text:
International Nuclear Information System (INIS)
A review of the more important passages for the field of the radiological protection, from the discovery, beginnings of the utilization of the radiations emitting, passing to the legislation proposals and the transformations that had been suffer to establish the international standards of radiological protection. The paradigms on the effects and chronologically the emanated discoveries of the cellular research and the measurement of cellular products in the species and the diverse alive beings making emphasis in evaluating the expression of the heat-shock proteins caused by low doses of gamma radiation, these are used as radiation bio monitors and of other agents that cause cellular stress and lastly a prospective of the future of the radiobiology. (Author)
HSP as bio dosemeters; HSP como biodosimetros
Energy Technology Data Exchange (ETDEWEB)
Manzanares A, E.; Vega C, H.R. [Grupo Academico de Radiobiologia, UAZ, A.P. 336, 98000 Zacatecas (Mexico)
A review of the more important passages for the field of the radiological protection, from the discovery, beginnings of the utilization of the radiations emitting, passing to the legislation proposals and the transformations that had been suffer to establish the international standards of radiological protection. The paradigms on the effects and chronologically the emanated discoveries of the cellular research and the measurement of cellular products in the species and the diverse alive beings making emphasis in evaluating the expression of the heat-shock proteins caused by low doses of gamma radiation, these are used as radiation bio monitors and of other agents that cause cellular stress and lastly a prospective of the future of the radiobiology. (Author)
Passive neutron dosemeter design
International Nuclear Information System (INIS)
A passive neutron dosemeter was designed to be used in mixed radiation fields. The design was carried out using Monte Carlo method. The dosemeter model was a 25.4 cm-diameter polyethylene sphere with a thermoluminescent dosemeter, TLD600, located at the sphere center. This model was irradiated with 50 monoenergetic neutron sources with energies from 10-8 to 20 MeV. A 506.71 cm2-area disk was used to model the source term whose center was located at 100 cm from polyethylene sphere's center. The dosemeter response was compared with the responses of SNOOPY, Harwell 95/0075 and PNR-4. With these responses it was calculated the dosemeter responses for 252Cf, 252Cf/D2O and 239PuBe neutron sources. The passive dosemeter relative response has the same shape of SNOOPY, Harwell 95/0075 and PNR-4 dosemeters. Due to the type of thermal neutron detector used in the passive dosemeter the absolute response per unit fluence, is lower than the absolute response of SNOOPY, Harwell 95/0075 and PNR-4 dosemeters. However the passive dosemeter response in function of the average neutron energy of the 252Cf, 252Cf/D2O and 239PuBe neutron energy was more linear
Calibration of farmer dosemeters
International Nuclear Information System (INIS)
The Farmer Dosemeters of Atomic Energy Medical Centre (AEMC) Jamshoro were calibrated in the Secondary Standard Dosimetry Laboratory (SSDL) at PINSTECH, using the NPL Secondary Standard Therapy level X-ray exposure meter. The results are presented in this report. (authors)
European intercomparison of diagnostic dosemeters: calibration of the reference dosemeters
International Nuclear Information System (INIS)
The paper describes both the organisational and technical steps taken in the calibration of the reference dosemeters used in the intercomparison of diagnostic dosemeters carried out in Europe in 1990. A brief account is given on the activities by the coordinating centres in the 19 countries and by the calibrating institution to establish the operational framework necessary for carrying out the calibration. The second part describes the calibration of the dosemeters against PTB's primary standards in terms of the equipment used and of the individual steps of measurement taken. An assessment of the uncertainties associated with the calibration is presented
Response of electret dosemeter to slow neutrons
International Nuclear Information System (INIS)
The response of the electret dosemeter to exposition of slow neutrons is studied. Different external coatings are used on the dosemeter (polyethylene, alminium, polyethylene + boron, aluminium + boron) and exposure curves (with and without water) are compared. (M.A.C.)
Colour dosemeters for high level radiation dosimetry
DEFF Research Database (Denmark)
Schönbacher, H.; Coninckx, F.; Miller, A.;
Development work was undertaken in order to produce a visual dosemeter system for measurement of radiation levels around the present and future high energy particle accelerators. This dosemeter should exhibit radiation induced colours in the visible part of the spectrum leading to a visual dose...... radiation; and (2) a paint containing a base substance with a pigment. The paint dosemeter remained unaffected by irradiation up to 3 x 10(4) Gy while the film dosemeter showed a measurable colour change from 10(4) Gy to 5 x 10(5) Gy. Above 10(6) Gy the film dosemeter is destroyed by radiation. Samples...
Calibration of neutron albedo dosemeters.
Schwartz, R B; Eisenhauer, C M
It is shown that by calibrating neutron albedo dosemeters under the proper conditions, two complicating effects will essentially cancel out, allowing accurate calibrations with no need for explicit corrections. The 'proper conditions' are: a large room (> or = 8 m on a side). use of a D2O moderated 252Cf source, and a source-to-phantom calibration distance of approximately 70 cm. PMID:12212898
Passive neutron dosemeter with activation detector
Energy Technology Data Exchange (ETDEWEB)
Valero L, C.; Banuelos F, A.; Guzman G, K. A.; Borja H, C. G.; Hernandez D, V. M.; Vega C, H. R., E-mail: email@example.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)
A passive neutron dosemeter with {sup 197}Au activation detector has been developed. The area dosemeter was made as a 20.5 {phi} x 20.5 cm{sup 2} polyethylene moderator, with a polyethylene pug where a {sup 197}Au foil can be located either parallel or perpendicular to moderator axis. Using Monte Carlo methods, with the MCNP5 code. With the fluence response and the fluence-to-equivalent dose conversion coefficients from ICRP-74, responses to H*(10) were also calculated, these were compared against responses of commercially available neutron area monitors and dosemeters. (Author)
Luszik-Bhadra, M
A field-dependent correction factor can be obtained by comparing the readings of two albedo neutron dosemeters fixed in opposite directions on a polyethylene sphere to the H*(10) reading as determined with a thermal neutron detector in the centre of the same sphere. The work shows that the field calibration technique as used for albedo neutron dosemeters can be generalised for all kind of dosemeters, since H*(10) is a conservative estimate of the sum of the personal dose equivalents Hp(10) in two opposite directions. This result is drawn from reference values as determined by spectrometers within the EVIDOS project at workplace of nuclear installations in Europe. More accurate field-dependent correction factors can be achieved by the analysis of several personal dosimeters on a phantom, but reliable angular responses of these dosemeters need to be taken into account. PMID:26493946
New dose quantities for personnel dosemeters
International Nuclear Information System (INIS)
In 1985, the Workshop External Dosimetry (AKD) of the German-Swiss 'Fachverband fuer Strahlenschutz' and the Physikalisch-Technische Bundesanstalt (PTB) organized an intercomparison experiment in order to find out whether commonly used personal dosemeters are able to indicate the new ICRU dose quantities (ICRU 39) Hs (0,07) and Hp(10) recommended for personal dosimetry. A total number of 30 representative dosimetry systems participated at the interlaboratory test. These systems make use mainly of L and RPL dosemeters, but also film dosemeters and direct reading dosemeters have been chosen. The irradiations have been performed over the energy range 25-662 keV using irradiations free in air as well as on the ICRU sphere phantom. Under an angle of 00, 450 and on the rotating phantom. The effect of phantom type has been investigated using the ICRU sphere and the Alderson human phantom. With respect to the ICRU quantities, three categories of personal dosemeters have been found dosemeter systems which simultaneously indicate the exposure X as well as H'(0,07) and H'(10) without any change of the evaluation technique or energy compensation filter, dosemeter systems which must be improved either in the evaluation procedure or by using additional detector readings, and dosemeter systems which must be changed in the energy compensation filters. In different papers the participants discuss their own results. Additional contributions of the seminar are presented, which discuss general subjects of introducing new dose quantities and other concepts of calibration quantities for external dosimetry. (orig./HP)
Glass as a gamma ray dosemeter
International Nuclear Information System (INIS)
The advantages of glass as a γ-rays dosemeter are studied. Experiments have shown that ordinary microscope object glass can be used as a dosemeter, which dose range for linear response extends from about 104-106 rads. Heat treatment of the irradiated samples accelerates the initial fading of coloration and stabilizes the residual optical density. On the other side cooling of them retards the initial fading. (author)
Self-indicating radiation alert dosemeter (SIRAD)
International Nuclear Information System (INIS)
In an event of a nuclear or dirty bomb explosion and a radiological accident, there is a need for self-indicating instant radiation dosemeter for monitoring radiation exposure. The self-indicating instant radiation alert dosemeter (SIRAD) is a credit card size radiation dosemeter for monitoring ionising radiation from a few hundredths of a Gray to a few Gray. It is always active and is ready to use. It needs no battery. The dosemeter develops colour instantly upon exposure, and the colour intensifies with dose. It has a colour chart so that the dose on the active element may be read by matching its colour with the chart that is printed next to it on the card. However, in this work, the dose is measured by the optical density of the element. The dosemeter cannot be reset. The response changes by 3 y at room temperature. It contains no hazardous materials. The dosemeter would meet the requirements of instantly monitoring high dose in an event of a nuclear or dirty bomb explosion or a radiation accident. (authors)
The relative merits of discriminating and non-discriminating dosemeters
DEFF Research Database (Denmark)
Marshal, T. O.; Christensen, Palle; Julius, H. W.;
The need for discriminating and non-discriminating personal dosemeters in the field of radiological protection is examined. The ability of various types of dosemeter to meet these needs is also discussed. It is concluded that there is a need for discriminating dosemeters but in the majority...... of cases a simple two element non-discriminating dosemeter will suffice. In cases where the use of discriminating dosemeters is justified, thermoluminescence dosemeters can be designed to provided information on radiation type and energy, but if further information is required the photographic film...
Thermoluminescent lithium fluorides dosemeters in personnel monitoring in the GDR
International Nuclear Information System (INIS)
Described are thermoluminescent (TL) dosemeters of lithium fluoride used in centralized personnel monitoring in the GDR. Results of large-scale experiment are presented to compare the accuracy of readings of lithium fluoride or teflon dosemeter and that of film dosemeters. 332 persons were controlled for the experiment. A phantom was irradiated simultaneously by X and gamma radiation. The experience in application of thermoluminescent dosemeters to personnel monitoring of radiation load of a whole body and body parts using rings is described. Two Types of TL ring dosemeters for measuring X, gamma and deta radiations are presented. Advantage and shortcomings of TL dosemeters are noted
Neutron dosimetry with TL albedo dosemeters at high energy accelerators
International Nuclear Information System (INIS)
The GSF-Personal Monitoring Service uses the TLD albedo dosemeter as standard neutron personal dosemeter. Due to its low sensitivity for fast neutrons however, it is generally not recommended for workplaces at high-energy accelerators. Test measurements with the albedo dosemeter were performed at the accelerator laboratories of GSI in Darmstadt and DESY in Hamburg to reconsider this hypothesis. It revealed that the albedo dosemeter can also be used as personal dosemeter at these workplaces, because at all measurement locations a significant part of neutrons with lower energies could be found, which were produced by scattering at walls or the ground. (authors)
Calibrations of pocket dosemeters using a comparison method
International Nuclear Information System (INIS)
This monograph is dedicated mainly to the calibration of pocket dosemeters. Various types of radiation sources used in hospitals and different radiation detectors with emphasis on ionization chambers are briefly presented. Calibration methods based on the use of a reference dosemeter were developed to calibrate all pocket dosemeters existing at the Radiation Physics and Metrology Laboratory. Some of these dosemeters were used in personnel dosimetry at hospitals. Moreover, a study was realized about factors that affect the measurements with pocket dosemeters in the long term, such as discharges due to cosmic radiation. A DBASE IV program was developed to store the information included in the hospital's registry
Neutron dosimetry with TL albedo dosemeters at high energy accelerators.
Haninger, T; Fehrenbacher, G
The GSF-Personal Monitoring Service uses the TLD albedo dosemeter as standard neutron personal dosemeter. Due to its low sensitivity for fast neutrons however, it is generally not recommended for workplaces at high-energy accelerators. Test measurements with the albedo dosemeter were performed at the accelerator laboratories of GSI in Darmstadt and DESY in Hamburg to reconsider this hypothesis. It revealed that the albedo dosemeter can also be used as personal dosemeter at these workplaces, because at all measurement locations a significant part of neutrons with lower energies could be found, which were produced by scattering at walls or the ground. PMID:17766258
Unbiased metal oxide semiconductor ionising radiation dosemeter
International Nuclear Information System (INIS)
To assess the application of MOS devices as low dose rate dosemeters, the sensitivity is the major factor although little studies have been performed on that subject. It is studied here, as well as thermal stability and linearity of the response curve. Other advantages are specified such as large measurable dose range, low cost, small size, possibility of integration. (D.L.)
Principle and use of dosemeters; Principe et utilisation des dosimetres
Energy Technology Data Exchange (ETDEWEB)
Genet, S.; Ribaud, I.
The institute of nuclear physics of Orsay is accepted by the Ministry of Labour to insure the surveillance of workers individual external exposure against the danger of ionizing radiations and to execute monitoring of radiation protection. The dosemeters studied in this report are the photographic film dosemeters ( for x rays, gamma rays and beta {sup -} rays), the trace detectors (fast neutrons) and the radio thermo luminescent dosemeters. For each type, the principle and how to use it are given. (N.C.).
Factors affecting polyamide prototypes design of Albedo dosemeters
International Nuclear Information System (INIS)
This work studies the most important factors which affect the response of albedo neutron dosemeters containing LiF TLDs with the aim to improve their sensitivity. It includes tests of thickness and shape of the polyamide moderator body prototypes, albedo window diameter and TLD position inside the moderator. Analyzing the results, an albedo neutron dosemeter prototype, B4C covered, was developed. The prototype has a response three times higher than the albedo dosemeter now in use in Brazil. (author)
Passive neutron dosemeter-spectrometer for high-energy accelerators
International Nuclear Information System (INIS)
A passive neutron dosemeter-spectrometer (PNDS) with fission fragments converters is described. The results obtained show that it is a convenient and reliable instrument for neutron dose equivalent measurement in the calibration performing and response investigations of personnel dosemeters in mixed radiation fields behind accelerator shielding. Because of the possibility of neutron spectrum estimation in a wide energy range PNDS using is promissing in the neutron radiation fields research and also as an accidental neutron dosemeter. 23 refs.; 10 figs.; 4 tabs
EURADOS intercomparison 2012 for neutron dosemeters
Energy Technology Data Exchange (ETDEWEB)
Fantuzzi, E. [ENEA-Radiation Protection Institute, Bologna (Italy); Chevallier, M.A. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France); Cruz-Suarez, R. [International Atomic Energy Agency, Vienna (Austria); Luszik-Bhadra, M. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Mayer, S. [Paul Scherrer Institute (PSI), Villigen (Switzerland); Thomas, D.J. [National Physical Laboratory (NPL), Teddington (United Kingdom); Tanner, R. [Public Health England, Oxon (United Kingdom); Vanhavere, F. [SCK-CEN, Belgian Nuclear Research Centre, Mol (Belgium)
EURADOS, within the work performed by Working Group 2 - Harmonization of Individual Monitoring in Europe, has started a self-sustained programme of regular intercomparisons and has successfully executed three intercomparisons for whole body photon dosemeters (IC2008, IC2010, IC2012) and one intercomparison for extremity dosemeters for photon and beta fields (IC2009). In 2012, the EURADOS intercomparison IC2012n was launched for personal neutron dosemeters routinely used to measure personal dose equivalent, Hp(10), in individual monitoring. No systems under development were allowed to participate. IC2012n was carried out by a EURADOS nominated Organization Group (OG) consisting of: Marie- Anne Chevallier (IRSN, F), Rodolfo Cruz-Suarez (IAEA, UN-Vienna), Marlies Luszik-Bhadra (PTB, D), Sabine Mayer (PSI, CH), David J. Thomas (NPL, UK), Rick Tanner (PHE, UK), Filip Vanhavere (SCK-CEN, B) led by a Coordinator, Elena Fantuzzi (ENEA, I). 31 participants registered for the comparison, with 34 dosimetry systems. In total 816 dosemeters were irradiated in selected neutron fields on an ISO slab phantom. The irradiations were performed at 2 European accredited laboratories which are both National Primary Metrology Laboratories for ionizing radiation: NPL (National Physical Laboratory, UK) and PTB (Physikalisch-Technische Bundesanstalt, D). All irradiations were carried out according to the irradiation plan developed by the OG. The overall results show that most, although not all, dosimetric systems perform acceptably well (within a factor of 2) for irradiations with a bare radionuclide source ({sup 252}Cf at 0 ), whilst more than half of the systems underestimate the reference value for irradiations from non-normal angles of incidence irradiations ({sup 252}Cf at 45 ) or for simulated workplace fields ({sup 252}Cf(D{sub 2}O) or {sup 252}Cf source behind a shadow cone). The performance for 250 keV mono-energetic neutron irradiations varies mainly reflecting the detection
Performance of the Harshaw DXT-RAD (TLD-100) dosemeter
Energy Technology Data Exchange (ETDEWEB)
Moor, D.M. [Defence Science and Technology Laboratory, Environmental Sciences Department, Alverstoke, Gosport, Hants PO12 2DL (United Kingdom)], E-mail: firstname.lastname@example.com; Horspool, B.; Stokes, R.P. [Defence Science and Technology Laboratory, Environmental Sciences Department, Alverstoke, Gosport, Hants PO12 2DL (United Kingdom)
The Defence Science and Technology Laboratory (Dstl) has type-tested the Harshaw DXT-RAD dosemeter against the International Standard ISO 12794:2000(E) 'Individual thermoluminescence dosemeters for extremities and eyes' [International Organization for Standardization, 2000. International Standard ISO 12794:2000(E). Nuclear energy-radiation protection-individual thermoluminescence dosemeters for extremities and eyes]. The tests carried out included batch homogeneity, reproducibility, linearity, detection threshold, environmental stability (temperature, humidity and light), self irradiation, isotropy, energy response, dose-rate response and neutron response. The DXT-RAD dosemeter satisfied all the requirements of ISO 12794:2000(E), with the exception of its response at low photon energies and intermediate beta energies. However, it should be noted that other forms of the DXT-RAD dosemeter with a thinner entrance window are available to give an improved response to low-energy radiations.
Barium dithionate as an EPR dosemeter.
Baran, M P; Bugay, O A; Kolesnik, S P; Maksimenko, V M; Teslenko, V V; Petrenko, T L; Desrosiers, M F
Electron paramagnetic resonance (EPR) dosimetry is growing in popularity and this success has encouraged the search for other dosimetric materials. Previous studies of gamma-irradiated barium dithionate (BaS(2)O(6) x 2H(2)O) have shown promise for its use as a radiation dosemeter. This work studies in greater detail several essential attributes of the system. Special attention has been directed to the study of EPR response dependences on microwave power, irradiation temperature, minimum detectable dose and post-irradiation stability. PMID:16565205
Thermal neutron dosimetry using MOSFET dosemeters
Energy Technology Data Exchange (ETDEWEB)
Fragopoulou, M., E-mail: firstname.lastname@example.com [Aristotle University of Thessaloniki, Physics Department, 54124 Thessaloniki (Greece); Siskos, S.; Manolopoulou, M.; Zamani, M. [Aristotle University of Thessaloniki, Physics Department, 54124 Thessaloniki (Greece); Sarrabayrouse, G. [LAAS du CNRS, University of Toulouse, 7 Av. Du Colonel Roche, 31077 Toulouse (France)
Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) with a LiF powder placed on their surface were used as neutron dosemeter. The effect of thermal neutron irradiation on the threshold voltage of the transistor was studied in order to determine the sensitivity of these detectors. Irradiations were performed at the thermal column of the reactor in IPTA, Demokritos, Athens and at the subcritical reactor of Nuclear Physics Laboratory, Thessaloniki. The sensitivity of the MOSFETs as a function of thermal neutron dose was found to be practically linear up to 100 mSv. The lower detectable dose appears to be depended on the dose rate.
Dosimetric characteristics of a TLD dosemeter with extremities
International Nuclear Information System (INIS)
It was designed a TLD dosemeter for the monitoring of the extremities. This one consists in a metallic ring with a circular orifice where is arranged a T L detector of LiF: Mg,Ti (Model JR1152C) 5 x 5 x 0.8 mm3 covered by a polyethylene fine layer. In this work were studied the dosimetric properties of the dosemeter for its application in the dosimetry of extremities for photonic radiation. the results obtained allow conclude that the designed dosemeter can be used for the extremities monitoring. (Author)
Household and workplace chemicals as retrospective luminescence dosemeters
DEFF Research Database (Denmark)
Thomsen, Kristina Jørkov; Bøtter-Jensen, L.; Murray, A.S.
, there are Other potential unheated crystalline materials found in the domestic and industrial environment which may also act as retrospective dosemeters, and may be considerably more sensitive. We have Surveyed the thermoluminescent and optically stimulated luminescent (OSL) characteristics of several...
Active electronic personal dosemeter in interventional radiology
International Nuclear Information System (INIS)
A recently developed active electronic personal dosemeter (AEPD) was utilised in order to measure the levels and the structure of occupational exposure to scattered X-ray radiation of medical staff who performed percutaneous revascularisation therapy that involves interventional radiology (IR) on the pelvis and upper leg arteries. The AEPDs, placed on the operators' and assistants' chests, that is, above the protective apron, continuously measured and recorded the received doses and, as a novelty, dose rates as a function of time, thus yielding a unique record of occupational doses and dose rates pattern at the working place. This paper presents and discusses one typical daily pattern in which seven percutaneous interventions were performed. (authors)
Response of Alanine Dosemeter to Heavy Ions
Institute of Scientific and Technical Information of China (English)
LiWenjian; SuXu; YangYingjie; YuanJianlei; DangBingrong; WangXiao; MaQiufeng; ZhouLibin; HaoJifang; MaoShuhong
The amino acid L-α-alanine has been investigated for use as a radiation detector in low and high LET radiation fields[1]. The radiatioa detector is cheap and easy to handle. The radiation inducing free radicals are stable at normal laboratory conditions for doses below 104 Gy over a long period of time, which makes the detector useful for intercomparison and documentation purposes. The dosimetric features of alanine-based electron spin resonance (ESR) detectors in high energy electron beams used in radiotherapy were considered[2]. The 5 mm long alanine detectors were found to be the most suitable for carrying out in vivo dosimetry on patients undergoing electron beam radiotherapy. However, data concerning dosimetry of the alanine dosemeter to heavy charged particles are lacking, especially in China.
Prediction analysis of dose equivalent responses of neutron dosemeters used at a MOX fuel facility.
Tsujimura, N; Yoshida, T; Takada, C
To predict how accurately neutron dosemeters can measure the neutron dose equivalent (rate) in MOX fuel fabrication facility work environments, the dose equivalent responses of neutron dosemeters were calculated by the spectral folding method. The dosemeters selected included two types of personal dosemeter, namely a thermoluminescent albedo neutron dosemeter and an electronic neutron dosemeter, three moderator-based neutron survey meters, and one special instrument called an H(p)(10) monitor. The calculations revealed the energy dependences of the responses expected within the entire range of neutron spectral variations observed in neutron fields at workplaces. PMID:21498409
Peptide substrate identification for yeast Hsp40 Ydj1 by screening the phage display library
Directory of Open Access Journals (Sweden)
Li Jingzhi
Full Text Available We have identified a peptide substrate for molecular chaperone Hsp40 Ydj1 by utilizing the combination of phage display library screening and isothemol titration calirimetry (ITC. The initial peptide substrate screening for Hsp40 Ydj1 has been carried out by utilizing a 7-mer phage display library. The peptide sequences from the bio-panning were synthesized and object to the direct affinity measurement for Hsp40 Ydj1 by isothemol titration calirimetry studies. The peptide which has the measurable affinity with Ydj1 shows enriched hydrophobic residues in the middle of the substrate fragment. The peptide substrate specificity for molecular chaperone Hsp40 has been analyzed.
Conversion from dosemeter readings to effective dose in individual dosimetric monitoring: effect of anisotropy of photon fields and dosemeter design
International Nuclear Information System (INIS)
Monte Carlo simulation (MCNP-4B code, ADAM phantom) was employed in order to estimate organ doses and doses to personal dosemeters of particular commercial design (one type of Harshaw dosemeter and two designs of RADOS dosemeters) in situations of irradiation of a person in photon radiation fields. For each photon energy and beam direction the partial conversion coefficients were calculated providing thus raw data for modeling of effective conversion coefficient in any photon radiation field. In practical situations, when specific orientation of a body in radiation field is not known or a person is changing his position and orientation, the most robust parameter representing geometry of exposure is anisotropy of radiation field. In order to assess effective conversion coefficients for variety of workplace conditions, both anisotropic field configuration and orientation of a person in radiation field were stochastically simulated and 95% percentile of stochastic distribution was taken as a value of effective conversion coefficient for given conditions of exposure. The value of effective conversion coefficient depends on anisotropy of radiation field and can be quantitatively derived for appropriate classes of anisotropy. For quasi-isotropic and moderately anisotropic fields effective conversion coefficient does not exceed unity (e.g. Hp(10) maintains conservatism) for all considered dosemeter types, while in strongly anisotropic fields Hp(10) is not conservative anymore and can underestimate effective dose. The described approach is illustrated by examples of appropriate effective conversion coefficients for several commonly used dosemeter types. (author)
The influence of the energy distribution of workplace fields on neutron personal dosemeter reading
International Nuclear Information System (INIS)
Variations in the energy dependence of response of neutron personal dosemeters cause systematic errors in the readings obtained in workplace fields. The magnitude of these errors has been determined theoretically by folding measured and calculated workplace energy distributions with dosemeter response functions, to determine the response of a given personal dosemeter in that field. These results have been analysed with consideration of the dosemeter response to various calibration spectra, and with reference to different workplaces. The dosemeters in the study are discussed in terms of the workplaces for which they can be suitably calibrated. Deficiencies in the published neutron energy distributions are identified
An international intercomparison of passive dosemeters, electronic dosemeters and dose rate meters used for environmental radiation measurements
DEFF Research Database (Denmark)
Bøtter-Jensen, L.; Thompson, I.M.G.
To assist towards the harmonisation within the EC countries, the Eastern European countries and the USA, of the measurement of environmental dose rates from photon radiation an EC sponsored intercomparison of environmental dose rate meters, electronic dosemeters and TL dosemeters was performed...... during 1994. The intercomparison was organised by the Physikalisch Technische Bundesanstalt (PTB), Braunschweig, Germany, and by the Riso National Laboratory, Roskilde, Denmark. This paper describes the intercomparison experiments performed at the newly established Riso Natural Environmental Radiation...... Measurement Stations during the period 12 to 18 June 1994. The chief aims of the experiments were to allow the participants to check their home calibrations of their detectors and to intercompare the dosemeter responses of the individual environmental radiation measurement systems used in the USA, Eastern...
Comparison on characteristics of radio-photoluminescent glass dosemeters and thermoluminescent dosemeters
International Nuclear Information System (INIS)
The radio-photoluminescent glass dosemeter (RPLGD) system is applicable for measurement of radiation dose of X-rays and gamma rays by using radio-photoluminescent glass (silver-activated phosphate glass). When the radio-photoluminescent glass is exposed to ionizing radiation, stable luminescent centres are created. During pulsed ultraviolet laser excitation (337.1 nm) in the reader, the centres emit a radiation induced orange fluorescent light (600-700 nm). This phenomenon is called radio-photoluminescence. This study compared the RPLGD system with lithium fluoride (LiF) thermoluminescence dosimetry system and the results of the study revealed that the RPLGD had not only good basic characteristics for reproducibility of readout value, dose linearity, energy dependence and fading, but also infinite repeatable measurements and could be one of the most important radiation dose measurement instruments. (authors)
Graphite mixed magnesium borate TL dosemeters for beta ray dosimetry
DEFF Research Database (Denmark)
Prokic, M; Christensen, Poul
Sintered MgB4O7:Dy dosemeters with graphite contents from 1 to 10% were investigated for application for personnel dosimetry. Data are given on dose response, dose threshold, reproducibility, beta energy response and fading. Furthermore, results from practical field experiments are presented...
Some characteristics of the AEOI Neutriran Albedo Neutron Personnel Dosemeter
International Nuclear Information System (INIS)
The Neutriran Albedo Personnel Neutron Dosemeter (NAPND) is based on the combination of a sensitive polymer such as polycarbonate (PC) in contact with 6LiF or 10B pellets in a cadmium cover. By adding a 10B pellet in front, the design of the dosemeter can be such that when worn on the body, direct thermal neutron induced alpha tracks (TNIAT), albedo neutron induced alpha tracks (ANIAT) and fast neutron induced recoil tracks (FNIRT) can be simultaneously detected in a single electrochemically etched PC foil. To establish a national personnel neutron dosimetry service in Iran, different parameters such as the effect of 10B(n,α)7Li convertor thickness, Cd thickness and its diameter, dosemeter distance from the phantom, dosemeter angle with phantom and directional response were studied using different phantoms. Under optimised conditions, a sensitivity of 1500 tracks.cm-2.mSv-1 for 252Cf neutrons with a lowest value of 0.05 mSv was measured. The results of these studies are reported and discussed. (author)
Radiological environmental monitoring with LiF-700-H dosemeters
Energy Technology Data Exchange (ETDEWEB)
Scarnichia, E.; Levanon, I.; Andres, P.; Miani, C.; Ramirez, S., E-mail: email@example.com [Comision Nacional de Energia Atomica, Centro Atomico Bariloche, Grupo Proteccion Radiologica, Exequiel Bustillo 5AV 9500, R8402AGP San Carlos de Bariloche, Rio Negro (Argentina)
Since 2008 a radiological environmental monitoring with LiF-700-H has been carried out as a result of increasing the Ra-6 research reactor core power. The information obtained is used to evaluate and to quantify analytically the air kerma rate, the fading and the associated uncertainty by developing software tools (deconvolution and uncertainty algorithms). LiF-700-H dosemeters were chosen because of their high sensitivity to low air kerma rates. They show a very good stability and a negligible fading for two-month working periods. The air kerma rate detection limit (based on the 3{sigma} criterion) during these working periods is about 0.4 n Gy/h. Air kerma rates of about 70 n Gy/h are measured with this detection limit. Following the Nist guidelines, an algorithm was developed in order to find the associated uncertainty. It considers several aspects, such as the source activity decay, distance source-dosemeter during the calibration procedure, irradiation time, calibration factor, dosemeter readout, dosemeter sensitivity, TLD reader stability and fading. The associated uncertainty is found to be about 25% for a 95% confidence interval (k = 2.025), which can be considered acceptable when taking into account the very low air kerma rates estimated. The LiF-700-H response to different energies and its relationship with climate changes over the calendar year are planned as future tasks. (Author)
Establishing local workplace field correction factors for neutron personal dosemeters
International Nuclear Information System (INIS)
The present personal neutron dosemeters still need local correction factors to be able to provide accuracy comparable with photon dosemeters. Characterisation of the local neutron field is an indispensable part of neutron dosimetry to obtain such correction factors. It is often overlooked that besides characterisation in the neutron energy also the directional distribution of neutrons plays a crucial part in this characterisation. The authors have done such characterisation in the energy and angle for four workplace fields in Paks NPP. For this a relatively simple approximation method was used using the Nprobe for the energy distribution and measurements on the six sides of the slab phantom with personal dosemeters for the directional distribution. This allowed one to estimate a reference neutron Hp(10) rate and to compare it with the response of several neutron personal dosemeters. In October 2011, a measurement campaign was set-up in Paks NPP, which is a VVER reactor type. The measurements were performed to estimate reference values for personal dose equivalent rates dHp(10)/dt and to evaluate the behaviour of several personal dosemeters at different locations inside the plant. Two locations in the pump room and two locations in the reactor hall were chosen. Instead of just assuming that the fluence is unidirectional or that the fluence is isotropic, an attempt was made to estimate the directional distribution of the neutron field using a relatively simple measurement procedure. A number of active and passive personal dosemeters were placed on the six faces of a slab phantom and the results were analysed to obtain partial fluences in several directions of incidence. This method has important limitations, but is relatively simple to perform. The results show that it is very important to include the directional distribution in the Hp(10) evaluation. When comparing Hp(10)/dt and H*(10)/dt, H*(10) can be considered a conservative value for Hp(10). In the pump room H
On the use of albedo dosemeters at the Dukovany nuclear power plant
International Nuclear Information System (INIS)
The response of the albedo dosemeter which is used as a personnel neutron dosemeter at the Dukovany nuclear power plant was studied. The design of the dosemeter was modified against the original version, whereby its dimensions were reduced and the dosemeter was augmented with a Cd shield to protect it against incident thermal neutrons. The study showed that the neutron spectrum inside the nuclear power plant varies over a wide range, and a correct interpretation of the albedo dosemeter data requires the use of a factor whose values can differ by as much as an order of magnitude. The results of the study allowed a procedure to be recommended for determining the Hp(10) value of the plant personnel using this device as an individual neutron dosemeter. (author)
Evaluation of BICRON NE MCP DXT-RAD passive extremity dosemeter
Yuen, P S; Frketich, G; Rotunda, J
Passive extremity dosemeters currently used in dosimetry communities worldwide have shortcomings. In general, an extremity dosemeter has too thick a detector element, and the dosemeter response is highly energy dependent for beta rays with energies ranging from 200 keV to 2 MeV. It often does not have dosemeter identification, causing problems in the chain of custody. It is often read manually, rendering reading/packing operations very labour intensive. As a result of collaboration between AECL and BICRON NE, a new extremity dosemeter, incorporating a highly sensitive LiF:Mg,Cu,P TLD and tentatively code named MCP DXT-RAD, was developed. It has been evaluated for radiological performance against an ISO draft standard for extremity dosemeters in twelve categories: homogeneity, detection threshold, beta ray energy response, beta angular response, photon energy response, photon angular response, reproducibility, stability under various climatic conditions, linearity, residue, self irradiation, and effect of ligh...
Test and optimization of two routine dosemeters for the dose quantity Hp(3)
International Nuclear Information System (INIS)
The individual monitoring service Seibersdorf uses two different passive dosemeter types based on thermo luminescence (TL) detectors for monitoring occupationally exposed persons in Austria. Whole body personal dosemeters for the personal dose equivalent quantities Hp(10) and Hp(0.07) worn on the trunk and dosemeters for the extremities for Hp(0.07) worn on a finger or wrist. Both routine dosemeters were calibrated and tested in terms of the personal dose equivalent Hp(3) assuming that the whole body dosemeter is worn on the chest (without or above a lead apron) and the modified ring/wrist dosemeter using a special strap worn on the forehead near the eyes (head band dosemeter). The test results show that it is possible to measure the dose quantity Hp(3) with these dosemeters that were originally not designed for this dose quantity. Only changes in the dose calculation algorithm and in the choice of the reference radiation quality were necessary to fulfil the requirements given in international standards for passive dosemeters in a wide energy (20 keV–1.3 MeV) and angular range (0°–60°). - Highlights: • Whole body dosemeter for Hp(10) and Hp(0.07) can also be used for Hp(3). • The dose algorithm for whole body dosemeter can be changed for Hp(3). • Extremity dosemeter for Hp(0.07) can also be used for Hp(3) on the forehead. • The reference energy has to be changed for Hp(3)
The use of extremity dosemeters in a hospital environment
International Nuclear Information System (INIS)
A general overview is given on the use of extremity dosemeters, their calibration, the units and phantoms to be used. One of the major applications of extremity dosemeters is to monitor the personnel in a hospital environment. In nuclear medicine, brachytherapy and interventional radiology (IR) skin doses to hands and legs can be substantial. Here, we report on two studies that are presently being undertaken in Belgium. The first one tries to map the dose distribution on the hands, in function of the manipulation in nuclear medicine. Some preliminary results are also given from a nationwide survey study for patient and personnel doses during IR and cardiology. The radiologists' hands, legs and forehead are monitored during a whole range of procedures in different hospitals. (authors)
Household and workplace chemicals as retrospective luminescence dosemeters
International Nuclear Information System (INIS)
In the development of techniques for the retrospective assessment of the dose absorbed by communities living and working adjacent to the site of a nuclear accident, attention has concentrated on the use of natural minerals such as quartz and feldspar as dosemeters. These minerals are widely found in household earthenware and almost all types of bricks and concrete. Their main disadvantages are variable and often low sensitivity, and the possibility of a comparatively large natural dose prior to the accident, depending on the age of the building and the type of building material. However, there are other potential unheated crystalline materials found in the domestic and industrial environment which may also act as retrospective dosemeters, and may be considerably more sensitive. We have surveyed the thermoluminescent and optically stimulated luminescent (OSL) characteristics of several such chemicals and this paper reports on the OSL sensitivity, the size of the residual dose immediately after manufacture, stability and derived minimum detection limits. (author)
Theoretical aspects of the design of a passive radon dosemeter.
Wilkinson, P; Saunders, B J
Some mathematical aspects of the development and design of a passive radon dosemeter are considered. In particular, a mathematical model is presented that is concerned with the gaseous diffusion of radon into a confined region bounded by a plastic material of known diffusion coefficient. The relationship between the time-integrated radon concentrations, inside and outside a sealed plastic container are derived. Estimates of the exposure of people to radon can be made using the time integrated radon concentration inside a calibrated container containing a CR-39 etched-track device. As a consequence of the analysis, it is possible to design a passive radon dosemeter that will be accurate, resistant to moisture and whose response will be independent of rapid variations in radon concentration. The possibility of using a container of this type for the measurement of diffusion coefficients is discussed.
Dose equivalent conversion coefficients, instrument and dosemeter responses for a set of neutron radiation fields
International Nuclear Information System (INIS)
The results are presented of calculations of spectrum (energy and angle) weighted conversion coefficients from fluence to the quantities effective dose equivalent, ambient dose equivalent (H*(10)), directional dose equivalent at 10 mm (H'(10)) and MADE; and of the responses per unit fluence of a spherical rem meter, a nuclear emulsion dosemeter, an albedo dosemeter and a PADC (CR39) dosemeter, for a set of neutron spectra. Calculations have been performed for both unidirectional fields and for rotational symmetry. The values of conversion coefficients and instrument and dosemeter responses are compared. (author)
Development of active environmental and personal neutron dosemeters.
Nakamura, T; Nunomiya, T; Sasaki, M
For neutron dosimetry in the radiation environment surrounding nuclear facilities, two types of environmental neutron dosemeters, the high-sensitivity rem counter and the high-sensitivity multi-moderator, the so-called Bonner ball, have been developed and the former is commercially available from Fuji Electric Co. By using these detectors, the cosmic ray neutrons at sea level have been sequentially measured for about 3 y to investigate the time variation of neutron spectrum and ambient dose equivalent influenced by cosmic and terrestrial effects. Our Bonner ball has also been selected as the neutron detector in the International Space Station and has already been used to measure neutrons in the US experimental module. The real time wide-range personal neutron dosemeter which uses two silicon semiconductor detectors has been developed for personal dosimetry and is commercially available from Fuji Electric Co. This dosemeter has good characteristics, fitted to the fluence-to-dose conversion factor in the energy range from thermal energies to several tens of mega-electron-volts and is now widely used in various nuclear facilities.
Indian Academy of Sciences (India)
Alexzander Asea
Currently two mechanisms are recognized by which heat shock proteins (HSP) are released from cells; a passive release mechanism, including necrotic cell death, severe blunt trauma, surgery and following infection with lytic viruses, and an active release mechanism which involves the non classical protein release pathway. HSPs are released both as free HSP and within exosomes. This review covers recent findings on the mechanism by which stress induces the release of HSP72 into the circulation and the biological significance of circulating HSP72 to host defense against disease.
On the calibration of radiotherapy dosemeters in Australia
International Nuclear Information System (INIS)
Full text: Dosemeters for external beam radiotherapy are calibrated in Australia by ARPANSA, against the national primary standards of exposure and absorbed dose. The primary standards are free air chambers for exposure at low and medium energy X-rays, a graphite cavity chamber for exposure at 60Co, and a graphite calorimeter for absorbed dose at 60Co and high energy (MV) X -rays. Radiotherapy dosemeters are calibrated against these standards using a well documented formalism to provide calibration factors suitable for use with dosimetry protocols. A dosemeter usually comprises an ionization chamber connected to an independent electrometer. These are calibrated separately if possible. A combined calibration factor is reported together with the electrometer calibration factor (sensitivity). The dosimetry protocol used in radiotherapy centres in Australia and New Zealand is currently the simplified version of the IAEA TRS277 protocol, published by the New Zealand NRL and recommended by the ACPSEM. This protocol requires the use of an exposure or air kerma calibration factor at 60Co (Nx or Nk) to evaluate the absorbed dose to air calibration factor ND. The chamber is then placed in a water phantom with its centre displaced from the reference point by peff. ARPANSA can also supply calibration factors in absorbed dose to water (ND,w), as required as input to the new IAEA CoP. If an absorbed dose to water calibration factor is used by the radiotherapy centre, the chamber should be placed with its centre at the reference point in the water phantom. ARPANSA has for some years coordinated the participation of Australian radiotherapy centres in the IAEA TLD Quality Audit service. Note that this service does not represent a calibration and should not be referred to as such. The only calibration is that provided by ARPANSA for a reference dosemeter at each radiotherapy centre. As soon as the ANSTO SSDL is operational, calibrations of reference dosemeters will also be available
Hsp40s specify functions of Hsp104 and Hsp90 protein chaperone machines.
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Michael Reidy
Full Text Available Hsp100 family chaperones of microorganisms and plants cooperate with the Hsp70/Hsp40/NEF system to resolubilize and reactivate stress-denatured proteins. In yeast this machinery also promotes propagation of prions by fragmenting prion polymers. We previously showed the bacterial Hsp100 machinery cooperates with the yeast Hsp40 Ydj1 to support yeast thermotolerance and with the yeast Hsp40 Sis1 to propagate [PSI+] prions. Here we find these Hsp40s similarly directed specific activities of the yeast Hsp104-based machinery. By assessing the ability of Ydj1-Sis1 hybrid proteins to complement Ydj1 and Sis1 functions we show their C-terminal substrate-binding domains determined distinctions in these and other cellular functions of Ydj1 and Sis1. We find propagation of [URE3] prions was acutely sensitive to alterations in Sis1 activity, while that of [PIN+] prions was less sensitive than [URE3], but more sensitive than [PSI+]. These findings support the ideas that overexpressing Ydj1 cures [URE3] by competing with Sis1 for interaction with the Hsp104-based disaggregation machine, and that different prions rely differently on activity of this machinery, which can explain the various ways they respond to alterations in chaperone function.
Mechanisms of Hsp90 regulation
Prodromou, Chrisostomos
Heat shock protein 90 (Hsp90) is a molecular chaperone that is involved in the activation of disparate client proteins. This implicates Hsp90 in diverse biological processes that require a variety of co-ordinated regulatory mechanisms to control its activity. Perhaps the most important regulator is heat shock factor 1 (HSF1), which is primarily responsible for upregulating Hsp90 by binding heat shock elements (HSEs) within Hsp90 promoters. HSF1 is itself subject to a variety of regulatory processes and can directly respond to stress. HSF1 also interacts with a variety of transcriptional factors that help integrate biological signals, which in turn regulate Hsp90 appropriately. Because of the diverse clientele of Hsp90 a whole variety of co-chaperones also regulate its activity and some are directly responsible for delivery of client protein. Consequently, co-chaperones themselves, like Hsp90, are also subject to regulatory mechanisms such as post translational modification. This review, looks at the many different levels by which Hsp90 activity is ultimately regulated. PMID:27515256
Results of an inquiry concerning experience gained in the use of thermoluminescent and phosphate glass dosemeters
International Nuclear Information System (INIS)
The report summarizes the results of an inquiry among users of thermoluminescent and phosphate glass dosemeters, carried out within the framework of the working group for 'external radiation dose measurement' of the Fachverband fuer Strahlenschutz eV. The data presented came in from 24 laboratories, showing their experience in the use of 38 different dosemeters. (orig.)
Development of Two-Dosemeter Algorithm for Better Estimation of Effective Dose Equivalent and Effective Dose
International Nuclear Information System (INIS)
An optimal algorithm, which suitably combines two dosemeter readings, one dosemeter on the chest and the other on the back, for better estimation of effective dose equivalent (HE) and effective dose (E), was developed by utilising hundreds of broad parallel photon beam irradiation geometries. The developed algorithm, weighting front (chest) and back dosemeter readings by 0.58 and 0.42, respectively, was found to be superior to other currently available algorithms, neither underestimating HE or E by more than 14%, nor overestimating by more than a few tens of a per cent for a broad range of frontal and dorsal incident beams. Like other algorithms, however, this algorithm tends to overestimate HE and E significantly for the lateral, overhead and underfoot beam directions. This study also suggests that this overestimation problem significantly decreases when one uses typical commercial dosemeters instead of isotropic-responding dosemeters. (author)
Electron scattering effects on absorbed dose measurements with LiF-dosemeters
International Nuclear Information System (INIS)
The investigation deals with absorbed dose measurements with solid wall-less dosemeters. Electron scattering complicates both measurement of absorbed dose and its theoretical interpretation. The introduction of the dosemeter in a medium causes perturbations of the radiation field. This perturbation and its effect on the distribution of the absorbed dose inside the dosemeter is studied. Plane-parallel LiF-teflon dosemeters (0.005 - 0.1 g.cm-2) are irradiated by a photon beam (137Cs) in different media. The investigation shows that corrections must be made for perturbations caused by electron scattering phenomena. Correction factors are given for use in accurate absorbed dose determinations with thermoluminescent dosemeters. (Auth.)
Performance of several active personal dosemeters in interventional radiology and cardiology
International Nuclear Information System (INIS)
Active personal dosemeters (APDs) are very useful instruments for optimizing radiation protection of workers and for increasing worker's awareness of unexpected exposures. The challenge of monitoring personal equivalent doses with APDs in interventional fluoroscopy is that they must be sensitive to low energy photon beams and be able to record high dose rates. The aim of this work is to verify both the performance and the reliability of four active personal dosemeters (APDs) and one direct ion storage (DIS) dosemeter in typical X-ray radiation fields used during interventional radiology and cardiology (IR/IC) procedures. The values of the personal dose equivalent at a depth of 10 mm measured by the APDs are compared with the response of a whole body thermoluminescence dosemeter (TLD) as a reference dosemeter. The response is found to be satisfactory in the tested situations.
A Method for evaluating personal dosemeters in workplace with neutron fields
International Nuclear Information System (INIS)
Passive detectors, as albedo or track-etch, still dominate the field of neutron personal dosimetry, mainly due to their low-cost, high-reliability and elevated throughput. However, the recent appearance in the market of electronic personal dosemeters for neutrons presents a new option for personal dosimetry. In addition to passive detectors, electronic personal dosemeters necessitate correction factors, concerning their energy and angular response dependencies. This paper reports on the results of a method to evaluate personal dosemeters for workplace where neutrons are present. The approach here uses few instruments and does not necessitate a large mathematical workload. Qualitative information on the neutron energy spectrum is acquired using a simple spectrometer (Nprobe), reference values for H*(10) are derived from measurements with ambient detectors (Studsvik, Berthold and Harwell) and angular information is measured using personal dosemeters (electronic and bubbles dosemeters) disposed in different orientations on a slab phantom. (authors)
A study of the irradiation temperature coefficient for L-alanine and DL-alanine dosemeters
International Nuclear Information System (INIS)
Alanine dosimetry is now well established both as a reference and routine dosemeter for industrial irradiation processing. Accurate dosimetry under the relatively harsh conditions of industrial processing requires a characterisation of the parameters that influence the dosemeter response. The temperature of the dosemeter during irradiation is a difficult quantity to measure so that the accuracy of the temperature coefficient that governs the dosemeter response becomes a critical factor. Numerous publications have reported temperature coefficients for several types of alanine dosemeters. The observed differences in the measured values were commonly attributed to the differences in the polymer binder or the experimental design of the measurement. However, the data demonstrated a consistent difference in the temperature coefficients between L-alanine and DL-alanine. Since there were no commonalities in the dosemeter composition or the measurement methods applied, a clear conclusion is not possible. To resolve this issue, the two isomeric forms of alanine dosemeters were prepared and irradiated in an identical manner. The results indicated that the DL-alanine temperature coefficient is more than 50% higher than the L-alanine temperature coefficient. (authors)
Dosimetric characteristics of a TLD dosemeter with extremities; Caracteristicas dosimetricas de un dosimetro TLD de extremidades
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Molina P, D.; Diaz B, E.; Lien V, R. [Centro de Proteccion e Higiene de las Radiaciones, CPHR, Apdo.Postal 6195, Habana 6, CP 10600, Ciudad Habana (Cuba)
It was designed a TLD dosemeter for the monitoring of the extremities. This one consists in a metallic ring with a circular orifice where is arranged a T L detector of LiF: Mg,Ti (Model JR1152C) 5 x 5 x 0.8 mm{sup 3} covered by a polyethylene fine layer. In this work were studied the dosimetric properties of the dosemeter for its application in the dosimetry of extremities for photonic radiation. the results obtained allow conclude that the designed dosemeter can be used for the extremities monitoring. (Author)
A digital interface for preset time or voltage measurements using an ionising radiation dosemeter
International Nuclear Information System (INIS)
A digital interface circuit has been built to terminate charge collection measurements made with an ionising radiation dosemeter. A compact portable measurement system has been assembled, comprising a digital voltmeter, a period timer and the digital interface module. Digital signals from both the voltmeter and the timer are compared with separate preset limits, and the dosemeter measurement is terminated when one of these limits is reached. The operation of the dosemeter is outlined, and the interface circuit is described in detail. Modifications to the voltmeter and timer are described, and comprehensive users' instructions are given
The assembly and intermolecular properties of the Hsp70-Tomm34-Hsp90 molecular chaperone complex.
Trcka, Filip; Durech, Michal; Man, Petr; Hernychova, Lenka; Muller, Petr; Vojtesek, Borivoj
Maintenance of protein homeostasis by molecular chaperones Hsp70 and Hsp90 requires their spatial and functional coordination. The cooperation of Hsp70 and Hsp90 is influenced by their interaction with the network of co-chaperone proteins, some of which contain tetratricopeptide repeat (TPR) domains. Critical to these interactions are TPR domains that target co-chaperone binding to the EEVD-COOH motif that terminates Hsp70/Hsp90. Recently, the two-TPR domain-containing protein, Tomm34, was reported to bind both Hsp70 and Hsp90. Here we characterize the structural basis of Tomm34-Hsp70/Hsp90 interactions. Using multiple methods, including pull-down assays, fluorescence polarization, hydrogen/deuterium exchange, and site-directed mutagenesis, we defined the binding activities and specificities of Tomm34 TPR domains toward Hsp70 and Hsp90. We found that Tomm34 TPR1 domain specifically binds Hsp70. This interaction is partly mediated by a non-canonical TPR1 two-carboxylate clamp and is strengthened by so far unidentified additional intermolecular contacts. The two-carboxylate clamp of the isolated TPR2 domain has affinity for both chaperones, but as part of the full-length Tomm34 protein, the TPR2 domain binds specifically Hsp90. These binding properties of Tomm34 TPR domains thus enable simultaneous binding of Hsp70 and Hsp90. Importantly, we provide evidence for the existence of an Hsp70-Tomm34-Hsp90 tripartite complex. In addition, we defined the basic conformational demands of the Tomm34-Hsp90 interaction. These results suggest that Tomm34 represents a novel scaffolding co-chaperone of Hsp70 and Hsp90, which may facilitate Hsp70/Hsp90 cooperation during protein folding.
Study of performance of a dosemeter based on thermoluminescent materials for external personnel monitoring
International Nuclear Information System (INIS)
The performance of a dosemeter based on thermoluminescent materials, 7 LiF and 6 LiF, was investigated. The verification if the dosemeter response complies with tests recommended by national and international regulatory organizations was performed. Tests of angular and energy dependence, reproducibility, detectability threshold, batch homogeneity and others were carried out and the obtained response is herein presented. Dosemeter response was evaluated in terms of Hp(10). The tests were carried out taking into account the IRD-RT No 001.01/95 and IEC 1066 reporters that gave the guidelines for this evaluation. The obtained response showed that the studied dosemeter complies with the tests and can be employed for individual monitoring. (author)
Conversion factors for the ICRU dose equivalent quantities for calibrating radiation dosemeters
International Nuclear Information System (INIS)
Report describing the application of conversion factors for monoenergetic photon radiation and for X and gamma reference radiation used for dosemeter calibration with the aid of spherical or rectangular phantoms (environmental and individual monitoring). (DG)
The role of phantom parameters on the response of the AEOI Neutriran Albedo Neutron Personnel Dosemeter
International Nuclear Information System (INIS)
The response of the AEOI Neutriran Albedo Neutron Personnel Dosemeter (NANPD) which can also be used for other albedo dosemeter types was determined on 18 different phantom configurations. The effects of type, geometry, material, thickness, dosemeter-to-phantom angle in particular with the presence of legs were investigated using a Pu-Be neutron source. It was concluded that the slab phantoms (single or double) and circular and elliptical cylinder phantoms seemed to provide a better response, whereas the ICRU sphere geometry does not seem to be appropriate for the calibration of albedo dosemeters. It is interesting to note that the presence of legs maintains the constancy of the response in a situation when a radiation worker bends down during work. (author)
The calibration of personal dosemeters used for evaluating exposure to solar UV in the workplace.
Sisto, R; Lega, D; Militello, A
In the framework of an epidemiological study regarding the correlation between solar UV radiation exposure and skin pathologies in a population of outdoor workers, the possibility of using polysulphone film personal dosemeters to quantify the Subjects UVB exposure has been evaluated. An original experimental set-up is presented. in a preliminary version, which ill be used both for solar irradiance spectroradiometric measurements and for the reading of personal dosemeters. The polysulphone absorption is similar to the CIE erythemal response curve. Due to UVB radiation exposure, the polysulphone film dosemeters photodegrade with a measrable absorbance change. The absorbance variation after the dosemeter exposure to UV radiation has been correlated to the UVB effective dose. The calibration curve obtained by this method may be particularly useful for the evaluation of small closes. The method will be used to quantify the personal exposure of workers whose exposure conditions are characterised by high variability. PMID:11878432
The calibration of personal dosemeters used for evaluating exposure to solar UV in the workplace
International Nuclear Information System (INIS)
In the framework of an epidemiological study regarding the correlation between solar UV radiation exposure and skin pathologies in a population of outdoor workers, the possibility of using polysulphone film personal dosemeters to quantify the subjects UVB exposure has been evaluated. An original experimental set-up is presented, in a preliminary version, which will be used both for solar irradiance spectroradiometric measurements and for the reading of personal dosemeters. The polysulphone absorption is similar to the CIE erythemal response curve. Due to UVB radiation exposure, the polysulphone film dosemeters photodegrade with a measurable absorbance change. The absorbance variation after the dosemeter exposure to UV radiation has been correlated to the UVB effective dose. The calibration curve obtained by this method may be particularly useful for the evaluation of small doses. The method will be used to quantify the personal exposure of workers whose exposure conditions are characterised by high variability. (author)
Determination of relevant parameters for the use of electronic dosemeters in pulsed fields of ionising radiation.
Zutz, H; Hupe, O; Ambrosi, P; Klammer, J
Active electronic dosemeters using counting techniques are used for radioprotection purposes in pulsed radiation fields in X-ray diagnostics or therapy. The disadvantage of the limited maximum measurable dose rate becomes significant in these radiation fields and leads to some negative effects. In this study, a set of relevant parameters for a dosemeter is described, which can be used to decide whether it is applicable in a given radiation field or not. The determination of these relevant parameters-maximum measurable dose rate in the radiation pulse, dead time of the dosemeter, indication per counting event and measurement cycle time-is specified. The results of the first measurements on the determination of these parameters for an electronic personal dosemeter of the type Thermo Fisher Scientific EPD Mk2 are shown.
Digital Dosemeters - 'ALARA OD' - Personal and Environmental Monitoring Assembly
International Nuclear Information System (INIS)
Full text: The importance of prompt dose reporting rises when dose is received within short-time interval or when the radiation source suffers technical failures. New dosimetry concept, where radiation exposure is recognized as a private /or/ group hazard of each person involved in occupational ionizing sources handling, taking into account actual radiation quality of the source, based among other principles, on the principle of establishing the well defined controlled area is introduced. New digital dosemeter device, produced by ALARA Instruments Ltd., measures small occupational doses, including the background. Device is based on ionizing GM tube, a set of modern EEPROM memory chips and Li compound battery set. It operates in two modes and the measurements are continuously performed no matter which mode is on. First mode integrates the dose (including background). If user or dosemeter device enter the higher radiation field area second mode will separately start to measure the dose which is at least two times higher than the surrounding background. The level above which the higher field is considered has to be preprogrammed during the calibration of device. Level depends on the workplace type /or/ environmental conditions where the device will be used. Device is suitable as well for the low level measurements and for the high radiation outputs. When used in the stronger fields, several devices can form a field monitoring system. Device is suitable for the various non-occupational purposes. With some telecommunication electronics and technical improvement, this device is usable as a point (Ort) environmental measuring station. Probe is sensitive to the background radiation and it is fast enough to record any change in normal environmental radiation field, send the data to the central station and raise alarm if necessary. We have built a prototype for environmental monitoring connectable to any kind of telecommunication net. (author)
1983 ORNL intercomparison of personnel neutron and gamma dosemeters
Energy Technology Data Exchange (ETDEWEB)
Swaja, R.E.; Sims, C.S.; Greene, R.T.
The Ninth Personnel Dosimetry Intercomparison Study was conducted during April 19-21, 1983, at the Oak Ridge National Laboratory. Dosemeters from 33 participating agencies were mounted on water-filled polyethylene elliptical phantoms and exposed to a range of low-level dose equivalents (0.02-0.45 mSv gamma and 0.49-11.14 mSv neutron) which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor served as the radiation source for six separate exposures which used four different shield conditions: unshielded and shielded with steel, steel/concrete, and concrete. Results of the neutron measurements indicate that it is not unusual for dose equivalent estimates made under the same conditions by different agencies to differ by more than a factor of 2. Albedo systems, which were the most popular neutron monitors in this study, provided the most accurate results with CR-39 recoil track being least accurate. Track and film neutron systems exhibited problems providing measurable indication of neutron exposure at dose equivalents of about 0.50 mSv. Gamma measurements showed that TLD and film systems generally overestimated dose equivalents in the mixed radiation fields with film exhibiting significant problems providing measurable indication of gamma exposure at dose equivalents lower than about 0.15 mSv. Under the conditions of this study in which exposures were carefully controlled and participants had information concerning exposure conditions and incident spectra prior to dosemeter analysis, only slightly more than half of all neutron and gamma dose equivalent estimates met regulatory accuracy standards relative to reference values. These results indicate that continued improvement of mixed-field personnel dosimetry is required by many participating organizations. 15 references, 30 tables.
1983 ORNL intercomparison of personnel neutron and gamma dosemeters
International Nuclear Information System (INIS)
The Ninth Personnel Dosimetry Intercomparison Study was conducted during April 19-21, 1983, at the Oak Ridge National Laboratory. Dosemeters from 33 participating agencies were mounted on water-filled polyethylene elliptical phantoms and exposed to a range of low-level dose equivalents (0.02-0.45 mSv gamma and 0.49-11.14 mSv neutron) which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor served as the radiation source for six separate exposures which used four different shield conditions: unshielded and shielded with steel, steel/concrete, and concrete. Results of the neutron measurements indicate that it is not unusual for dose equivalent estimates made under the same conditions by different agencies to differ by more than a factor of 2. Albedo systems, which were the most popular neutron monitors in this study, provided the most accurate results with CR-39 recoil track being least accurate. Track and film neutron systems exhibited problems providing measurable indication of neutron exposure at dose equivalents of about 0.50 mSv. Gamma measurements showed that TLD and film systems generally overestimated dose equivalents in the mixed radiation fields with film exhibiting significant problems providing measurable indication of gamma exposure at dose equivalents lower than about 0.15 mSv. Under the conditions of this study in which exposures were carefully controlled and participants had information concerning exposure conditions and incident spectra prior to dosemeter analysis, only slightly more than half of all neutron and gamma dose equivalent estimates met regulatory accuracy standards relative to reference values. These results indicate that continued improvement of mixed-field personnel dosimetry is required by many participating organizations. 15 references, 30 tables
Haninger, T; Henniger, J
A new official albedo dosemeter based on thermoluminescent detectors has been introduced in 2015 by the individual monitoring service of the Helmholtz Zentrum München for monitoring persons who are exposed occupationally against photon and neutron radiation. To enhance the sensitivity for fast neutrons, a new badge with an enlarged albedo window has been developed at TU Dresden. The properties of the new albedo dosemeter are discussed, and the results of official intercomparisons and field calibrations are shown. PMID:26405220
Quality assurance of personal beta particle dosemeters used for individual monitoring of occupationally exposed persons
International Nuclear Information System (INIS)
As a result of investigations and intercomparison measurements organised from 1996 to 1999 by PTB, several types of personal dosemeters, all based on TLD, were selected by the dosimetry services for the measurement of the personal dose equivalent Hp(0.07) in beta and/or photon radiation fields. These dosemeters have now the status of legal personal beta partial-body dosemeters. Workplaces at which beta radiation might significantly contribute to the doses to the extremities are to be found today with increasing frequency in radiation therapy, radiation source production and nuclear power plants. Quality assurance for beta personal dosemeters is stipulated by guidelines for the official dosimetry service and is carried out by way of the intercomparison measurements organised periodically by the PTB. The results are evaluated based on the recommendations of the German Commission on Radiological Protection (SSK). The procedure of these intercomparison measurements will be explained in detail. The experience gained from three series of comparisons with seven types of fingering dosemeters will be described and the results will be presented. The anonymity of the dosemeter types and of the participants in the intercomparison will be preserved. (authors)
Feasibility study of extremity dosemeter based on polyallyl-diglycol-carbonate (CR-39) for neutron exposure
International Nuclear Information System (INIS)
In nuclear facilities, some activities such as reprocessing, recycling and production of bare fuel rods expose the workers to mixed neutron-photon fields. For several workplaces, particularly in glove boxes, some workers expose their hands to mixed fields. The mastery of the photon extremity dosimetry is relatively good, whereas the neutron dosimetry still raises difficulties. In this context, the Inst. for Radiological Protection and Nuclear Safety (IRSN) has proposed a study on a passive neutron extremity dosemeter based on chemically etched CR-39 (PADC: polyallyl-diglycol-carbonate), named PN-3, already used in routine practice for whole body dosimetry. This dosemeter is a chip of plastic sensitive to recoil protons. The chemical etching process amplifies the size of the impact. The reading system for tracks counting is composed of a microscope, a video camera and an image analyser. This system is combined with the dose evaluation algorithm. The performance of the dosemeter PN-3 has been largely studied and proved by several laboratories in terms of passive individual neutron dosemeter which is used in routine production by different companies. This study focuses on the sensitivity of the extremity dosemeter, as well as its performance in the function of the level of the neutron energy. The dosemeter was exposed to monoenergetic neutron fields in laboratory conditions and to mixed fields in glove boxes at workplaces. (authors)
Individual monitoring with official electronic dosemeters in Germany - concepts and reality
International Nuclear Information System (INIS)
Full text: Active (electronic) personal dosemeters (APD) are radiometers, which are equipped as active or passive dosimeters. They can directly indicate a dose rate and/or the dose integrated during a certain period (direct-indicating, active electronic personal dosemeters mentioned) or only over a separate reader (direct-selectable, passive electronic personal dosemeters mentioned). A concept is presented for the use of passive or active electronic personal dosemeters in Germany as official dosemeters, e.g. in hospitals. The concept features a net-based approach for secure data communication between readers for passive and active electronic personal dosemeters und the official personal dosimetry monitoring service(s), taking the German policies (StrISchV und RoeV in hospitals) into account. The net-based solution includes a processor controlled interface via TCP/IP connected to the dosimetry reader(s), und reader interfaces, an official interim data bank and all the necessary equipment such as PC, Raid-configuration, USV support, network connection and further details. Investigations have been started to achieve highest-level data manipulation security, data completeness und data correctness. (author)
Personal neutron dosimetry in nuclear power plants using etched track and albedo thermoluminescence dosemeters
International Nuclear Information System (INIS)
Measurement of the personal dose equivalent rates for neutrons is a difficult task because available dosemeters do not provide the required energy response and sensitivity. Furthermore, the available wide calibration spectra recommended by the International Standard Organisation does not reproduce adequately the spectra encountered in practical situations of the nuclear industry. There is a real necessity to characterise the radiation field, in which workers can be exposed, and to calibrate personal dosemeters in order to determine the dose equivalent in these installations. For this reason, we measure the neutron spectrum with our Bonner sphere system and we fold this spectrum with energy-dependent fluence-to-dose conversion coefficients to obtain the reference dose equivalent rate. This reference value is then compared with the personal dosemeter reading to determine a field-specific correction factor. In this paper, we present the values of this field-specific correction factor for etched track and albedo thermoluminescence dosemeters at three measurement locations inside the containment building of the Vandellos II nuclear power plant. We have found that assigning to each personal dosemeter the mean value of the field-specific correction factors of the three measurement locations, allows the evaluation of neutron personal dose equivalent rate with a relative uncertainty of∼25 and 15% for the PADC and albedo dosemeters, respectively. (authors)
Personal neutron dosimetry in nuclear power plants using etched track and albedo thermoluminescence dosemeters.
Fernández, F; Bakali, M; Amgarou, K; Nourreddine, A; Mouhssine, D
Measurement of the personal dose equivalent rates for neutrons is a difficult task because available dosemeters do not provide the required energy response and sensitivity. Furthermore, the available wide calibration spectra recommended by the International Standard Organisation does not reproduce adequately the spectra encountered in practical situations of the nuclear industry. There is a real necessity to characterise the radiation field, in which workers can be exposed, and to calibrate personal dosemeters in order to determine the dose equivalent in these installations. For this reason, we measure the neutron spectrum with our Bonner sphere system and we fold this spectrum with energy-dependent fluence-to-dose conversion coefficients to obtain the reference dose equivalent rate. This reference value is then compared with the personal dosemeter reading to determine a field-specific correction factor. In this paper, we present the values of this field-specific correction factor for etched track and albedo thermoluminescence dosemeters at three measurement locations inside the containment building of the Vandellòs II nuclear power plant. We have found that assigning to each personal dosemeter the mean value of the field-specific correction factors of the three measurement locations, allows the evaluation of neutron personal dose equivalent rate with a relative uncertainty of approximately 25 and 15% for the PADC and albedo dosemeters, respectively. PMID:15353734
Whey protein hydrolysate enhances HSP90 but does not alter HSP60 and HSP25 in skeletal muscle of rats.
Directory of Open Access Journals (Sweden)
Carolina Soares Moura
Full Text Available Whey protein hydrolysate (WPH intake has shown to increase HSP70 expression. The aim of the present study was to investigate whether WPH intake would also influences HSP90, HSP60 and HSP25 expression, as well as associated parameters. Forty-eight male Wistar rats were divided into sedentary (unstressed and exercised (stressed groups, and were fed with three different sources of protein: whey protein (WP, whey protein hydrolysate (WPH and casein (CAS as a control, based on the AIN93G diet for 3 weeks. WPH intake increased HSP90 expression in both sedentary and exercised animals compared to WP or CAS, however no alteration was found from exercise or diet to HSP60 or HSP25. Co-chaperone Aha1 and p-HSF1 were also increased in the exercised animals fed with WPH in comparison with WP or CAS, consistent with enhanced HSP90 expression. VEGF and p-AKT were increased in the WPH exercised group. No alteration was found in BCKDH, PI3-Kinase (p85, GFAT, OGT or PGC for diet or exercise. The antioxidant system GPx, catalase and SOD showed different responses to diet and exercise. The data indicate that WPH intake enhanced factors related to cell survival, such as HSP90 and VEGF, but does not alter HSP60 or HSP25 in rat skeletal muscle.
Scattering correction for {sup 241}Am-Be calibration of an individual albedo neutron dosemeter
Energy Technology Data Exchange (ETDEWEB)
Freitas, Bruno M.; Martins, Marcelo M.; Patrao, Karla C.S.; Fonseca, Evaldo S.; Pereira, Walsan W.; Mauricio, Claudia L.P., E-mail: email@example.com, E-mail: email@example.com, E-mail: email@example.com, E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)
The Instituto de Radioprotecao e Dosimetria (IRD), RJ, Brazil, runs an individual albedo neutron dosemeter service. The albedo dosemeter response varies strongly with neutron energy, falling down very steeply in the energy range of radionuclide neutron source. Moreover the largest number of workers exposed to neutrons in Brazil is exposed to scattered and moderated {sup 241}Am-Be fields. Therefore a study of the response of albedo dosemeter due to neutron scattering from {sup 241}Am-Be source is very important for IRD albedo dosemeter calibration. In this work, it has been evaluated the scattering neutron correction in the calibration of the albedo dosemeter from a {sup 241}Am-Be source in the Low Scattering Laboratory of the Neutron Laboratory of the Brazilian National Metrology Laboratory of Ionizing Radiations, where IRD albedo neutron dosemeter is calibrated. It was used the shadow cone technique and Bonner sphere spectrometer with the BUMS (Bonner sphere Unfolding Made Simple) unfolding software. Using the results obtained for the values of H{sub p}(10) and the reading of IRD albedo neutron dosemeter, new calibration factors, considering the scattering in the laboratory, were calculated. These calculated factors for irradiation without the shadow cone are approximately the same for both studied distances and similar with the one calculated without taking in account the scattering contribution for a source-detector distance of 1.00 m (7% difference), but about 20% higher at 2.25 m. For the neutron scattered beam (with shadow cone), the calibration factor values are about 30% and 25% lower, respectively, for 1.00 and 2.25 m. (author)
Hsp10, Hsp70, and Hsp90 immunohistochemical levels change in ulcerative colitis after therapy
Directory of Open Access Journals (Sweden)
G. Tomasello
Full Text Available Ulcerative colitis (UC is a form of inflammatory bowel disease (IBD characterized by damage of large bowel mucosa and frequent extra-intestinal autoimmune comorbidities. The role played in IBD pathogenesis by molecular chaperones known to interact with components of the immune system involved in inflammation is unclear. We previously demonstrated that mucosal Hsp60 decreases in UC patients treated with conventional therapies (mesalazine, probiotics, suggesting that this chaperonin could be a reliable biomarker useful for monitoring response to treatment, and that it might play a role in pathogenesis. In the present work we investigated three other heat shock protein/molecular chaperones: Hsp10, Hsp70, and Hsp90. We found that the levels of these proteins are increased in UC patients at the time of diagnosis and decrease after therapy, supporting the notion that these proteins deserve attention in the study of the mechanisms that promote the development and maintenance of IBD, and as biomarkers of this disease (e.g., to monitor response to treatment at the histological level.
Comparison of the performance of a set of nine electronic personal dosemeters
Energy Technology Data Exchange (ETDEWEB)
Ortega, X.; Ginjaume, M. [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya (Spain); Hernandez, A.; Villanueva, I.; Amor, I. [Consejo de Seguridad Nuclear (Spain); Aran, J. [UNESA (Spain)
The purpose of the present paper is to provide an overview of the performance of a set of nine models of commercially available electronic personal dosemeters (EPD). It aims at establishing calibration and testing procedures for such devices in order to assure its reliability for secondary and primary personal dosimetry. A Protocol, which includes calibration and testing procedures as well as performance requirements for EPDs, is proposed. This document, based on IEC 1283, IEC-1526 and ISO 4037-3 standards, is used to verify the technical performance of the selected dosemeters. In the choice of the dosemeters, models, presently in use and connected to centralised dosimetric systems, and thus, more likely to eventually become official dosimeters, have been preferred. The following features have been evaluated: - Physical characteristics (size, weight, case, switches, data accessibility). - Electrical performance (batteries). - Radiological performance (measured quantity and type of radiation, range of measurement, accuracy, alarm output, energy response, angular response, response time, dose rate response dependence, overload signal). - Mechanical performance (drop and vibration test). - Influence of several environmental parameters (temperature, relative humidity and external electromagnetic fields, magnetic fields and electrostatic discharges). Most dosemeters have performed within the established criteria for the majority of the tested parameters. Nevertheless, some deficiencies have also been found. Among the most relevant considerations one can make the following comments: - Poor energy response for beta and low-energy photon radiation. - Few dosemeters are able to measure shallow dose (H{sub p}(0.07)). - Two of the tested dosemeters failed the drop test. - Several devices didn't give an overload signal while they were being irradiated at a dose rate higher than the available range. - Some dosemeters produced spurious signals when they were exposed to
Measurement of doses to aviator pilots using thermoluminescent dosemeters
International Nuclear Information System (INIS)
During the development of their work, the aviator pilots are exposed at high levels of natural radiation of bottom caused mainly by the cosmic radiation of galactic origin and lot. For such reason, the Metropolitan Autonomous University (UAM) and the Union Association of Aviator Pilots (ASPA), subscribed an agreement with the purpose of to measure the doses of ionizing radiation received by the aviator pilots of diverse air companies that man different types of airships and to determine if these doses surpass the one limit of 0.11 mSv/h settled down by the IAEA for the public in general; and if therefore, these workers should be considered as personnel occupationally exposed. In this work the obtained results when measuring the absorbed dose received by Mexican civil aviator pilots during the development of their work, using thermoluminescent dosemeters of LiF:Mg,Cu,P + Ptfe of national production are presented. The obtained results during the years of 2001 and 2002 show that the monthly doses received by the pilots surpass the one it limits established for the public in general, for what they should be considered as personnel occupationally exposed. (Author)
Calibration of extremity dosemeters for gamma radiation fields
International Nuclear Information System (INIS)
In this work the kerma conversion factor are free in air, dose equivalent H(d,0) are presented, they were obtained theoretical and experimentally in finger and arm for gamma radiation fields. Extremity dosemeters put on surface finger and arm phantom have been irradiated. The finger phantom is a solid cylinder of PMMA polymethylmethacrylate 19 mm diameter and 300 mm height. The arm phantom is a 73 mm external diameter cylinder with PMMA walls 2.5 mm thick fill with water and 300 mm height. The radiation sources were cobalt 60 and cesium 137 from the Regional Center of Reference (CRR) of the National Commission of Atomic Energy (CNEA) and the Nuclear Regulatory Authority (ARN). Also in ISO wide X ray spectra W60, W110 and W200 have been irradiated. The results obtained show a good correlation with those published, they have a difference less than 7%. The factors will be applied to the evaluation of the equivalent doses coming from workers whose main irradiated zone is in the hands. (author)
Numerical and experimental results of the operational neutron dosemeter 'Saphydose-N'.
Lahaye, T; Chau, Q; Ménard, S; Ndontchueng-Moyo, M; Bolognese-Milsztajn, T; Rannou, A
Since 1993, the Institute for Radiological Protection and Nuclear Safety (IRSN) has lead, in association with Electricité de France (EDF), a R&D study of a neutron personal electronic dosemeter. This dosemeter, called 'Saphydose-N', is manufactured by the SAPHYMO company. This paper presents first the optimisation of some detector components using Monte Carlo calculations, and second the test of the manufactured Saphydose-N under radiation following the IEC 1323 standard's recommendations for active personal neutron dosemeters. The measurements with the manufactured dosemeter were performed on the one hand at PTB (Physikalisch-Technische Bundesanstalt) in mono-energetic neutron fields and, on the other hand at IRSN in neutron fields generated by a thermal facility (SIGMA), radionuclide ISO sources and a realistic spectrum (CANEL/T400). The manufactured dosemeter Saphydose-N was also tested during measurement campaigns of the European programme EVIDOS ('Evaluation of Individual Dosimetry in Mixed Neutron and Photon Radiation Fields') at different nuclear workplaces. The study showed that Saphydose-N complies with the recommendations of standard IEC 1323 and can be used at any workplace with no previous knowledge of the neutron field characteristics.
Validation of a MOSFET dosemeter system for determining the absorbed and effective radiation doses in diagnostic radiology.
Manninen, A-L; Kotiaho, A; Nikkinen, J; Nieminen, M T
This study aimed to validate a MOSFET dosemeter system for determining absorbed and effective doses (EDs) in the dose and energy range used in diagnostic radiology. Energy dependence, dose linearity and repeatability of the dosemeter were examined. The absorbed doses (ADs) were compared at anterior-posterior projection and the EDs were determined at posterior-anterior, anterior-posterior and lateral projections of thoracic imaging using an anthropomorphic phantom. The radiation exposures were made using digital radiography systems. This study revealed that the MOSFET system with high sensitivity bias supply set-up is sufficiently accurate for AD and ED determination. The dosemeter is recommended to be calibrated for energies 80 kVp. The entrance skin dose level should be at least 5 mGy to minimise the deviation of the individual dosemeter dose. For ED determination, dosemeters should be implanted perpendicular to the surface of the phantom to prevent the angular dependence error. PMID:25213263
Independent evaluation of optically stimulated luminescence (OSL) 'dot' dosemeters for environmental monitoring.
Timilsina, Bindu; Gesell, Thomas F
Optically stimulated luminescence (OSL) 'dot' dosemeters (manufactured by Landauer®) are reported to have a high degree of environmental stability, high level of sensitivity and provide wide range of dose measuring capabilities from 0.05 mGy to 100 Gy. The optical read out method is fast and relatively simple and permits repeated read out, but few studies have been performed about its application in monitoring radiation in the environment. This study was initiated to independently test the performance of OSL dot dosemeters for the application of measuring doses of radiation in the outdoor environment. Testing was performed in the laboratory to evaluate reproducibility and stability and in the field to evaluate accuracy relative to calibrated high-pressure ionisation chambers. The results showed that OSL dot dosemeters had good reproducibility and stability in both laboratory and field tests and met the performance requirements of standards of the American National Standards Institute.
Operational comparison of TLD albedo dosemeters and solid state nuclear tracks detectors in fuel fabrication facilities
International Nuclear Information System (INIS)
The authors carried out an operational study that compared the use of TLD albedo dosemeters and solid state nuclear tracks detector in plutonium environments of Japan Nuclear Cycle Development Inst., Tokai Works. A selected group of workers engaged in the fabrication process of MOX (Plutonium-Uranium mixed oxide) fuel wore both TLD albedo dosemeters and solid state nuclear tracks detectors. The TL readings were generally proportional to the counted etch-pits, and thus the dose equivalent results obtained from TLD albedo dosemeter agreed with those from solid state nuclear tracks detector within a factor of 1.5. This result indicates that, in the workplaces of the MOX fuel plants, the neutron spectrum remained almost constant in terms of time and space, and the appropriate range of field-specific correction with spectrum variations was small in albedo dosimetry. (authors)
Determination of Energy and Angular Response of an Albedo Neutron Personal Dosemeter
International Nuclear Information System (INIS)
The result of the determination of energy and angular response for the albedo neutron personal dosemeter used by CPHR, is described. The dosemeters consist of two pairs of LiF detectors (6LiF+7LiF) separated by a piece of boron-loaded plastic. For the study, the dosemeters were irradiated in three mixed neutron-gamma fields (thermal neutrons, moderated 241Am-Be and 241Am-Be) and at two incidence angles of radiation (0 deg. and 60 deg. ). The variation of the sensibility at different neutron spectra and incidence angles of radiation was determined. The methodology of dose evaluation, applying the obtained coefficients, was established. (author)
A three element etched track neutron dosemeter with good angular and energy response characteristics
International Nuclear Information System (INIS)
A weakness of all single element etched track neutron dosemeters is that the sensitivity falls off too rapidly with increasing angle of incidence. This can lead to significant errors in practical situations. A possible solution is to incorporate in a single dosemeter one or more planar etched track detectors set at an angle to the body surface so that the sensitivity to obliquely incident neutrons is enhanced. The response of a dosemeter in which three planar elements are set in a pyramid structure is investigated. Relationships are developed which allow the response to be estimated for any given direction of incidence and any given angle between face and base of the pyramid. The results indicate that the response is close to that required to measure Hp(10) for any given direction of neutron incidence if the angle between face and base is between 30o and 40o. (author)
Estimating effective dose for a cardiac catheterisation procedure with single or double personal dosemeters
International Nuclear Information System (INIS)
In most countries of the European Union legislation requires individual determination and registration of the dose to radiological workers exposed to ionising radiation to check whether dose limits are exceeded. To assess stochastic risk, ideally effective dose (E) should be known. In practice, personal dose equivalent [Hp(10)] is used as it can be measured with a personal dosemeter. The dosemeter reading may provide a reasonable assessment of Hp(10), but it may deviate strongly from E, in particular in radiology procedures for medical diagnosis or intervention when protective clothing like lead-equivalent apron and thyroid collar is worn. In the literature various correction factors and algorithms to convert readings of single or dual dosemeters to an estimate of E can be found. An illustrative example of a cardiac catheterisation procedure, in which dose calculations are made by Monte Carlo simulation of radiation transport, shows that such corrections may still yield considerable overestimation. (authors)
Measurements of eye lens doses in interventional cardiology using OSL and electronic dosemeters
International Nuclear Information System (INIS)
The purpose of this paper is to test the appropriateness of OSL and electronic dosemeters to estimate eye lens doses at interventional cardiology environment. Using TLD as reference detectors, personal dose equivalent was measured in phantoms and during clinical procedures. For phantom measurements, OSL dose values resulted in an average difference of 215 % vs. TLD. Tests carried out with other electronic dosemeters revealed differences up to ±20 % versus TLD. With dosemeters positioned outside the goggles and when TLD doses were >20 μSv, the average difference OSL vs. TLD was 29 %. Eye lens doses of almost 700 μSv per procedure were measured in two cases out of a sample of 33 measurements in individual clinical procedures, thus showing the risk of high exposure to the lenses of the eye when protection rules are not followed. The differences found between OSL and TLD are acceptable for the purpose and range of doses measured in the survey (authors)
Electrostatic interactions of Hsp-organizing protein tetratricopeptide domains with Hsp70 and Hsp90: computational analysis and protein engineering.
Kajander, Tommi; Sachs, Jonathan N; Goldman, Adrian; Regan, Lynne
The Hsp-organizing protein (HOP) binds to the C termini of the chaperones Hsp70 and Hsp90, thus bringing them together so that substrate proteins can be passed from Hsp70 to Hsp90. Because Hsp90 is essential for the correct folding and maturation of many oncogenic proteins, it has become a significant target for anti-cancer drug design. HOP binds to Hsp70 and Hsp90 via two independent tetratricopeptide (TPR) domains, TPR1 and TPR2A, respectively. We have analyzed ligand binding using Poisson-Boltzmann continuum electrostatic calculations, free energy perturbation, molecular dynamics simulations, and site-directed mutagenesis to delineate the contribution of different interactions to the affinity and specificity of the TPR-peptide interactions. We found that continuum electrostatic calculations could be used to guide protein design by removing unfavorable interactions to increase binding affinity, with an 80-fold increase in affinity for TPR2A. Contributions at buried charged residues, however, were better predicted by free energy perturbation calculations. We suggest using a combination of the two approaches for increasing the accuracy of results, with free energy perturbation calculations used only at selected buried residues of the ligand binding pocket. Finally we present the crystal structure of TPR2A in complex with its non-cognate Hsp70 ligand, which provides insight on the origins of specificity in TPR domain-peptide recognition. PMID:19586912
Performance of a coupled albedo/CR-39 personal dosemeter for fast neutron radiation
International Nuclear Information System (INIS)
Full text: The individual monitoring of neutron radiation still constitutes a difficult task, due to the wide energy range of the workplace fields and the large variation of the fluence-to-Hp(10) conversion coefficient in such energy interval, which is very difficult to reproduce by the response of a personal dosemeter. Consequently, the overall uncertainty in the dose evaluation procedure is mainly due to the energy dependence of the dosemeter response, which, for commonly employed dosimetric techniques such as the CR-39 and TLD-albedo, is higher than ±50 % in the [0.5 - 4] MeV energy range. This problem can be reduced by using a workplace specific calibration factor, only applicable in those cases where an a priori knowledge of the neutron spectrum is provided. In order to provide accurate dosimetric evaluations in unknown spectra condition, a study was performed by combining the reading of electrochemically etched CR-39 and TLD-albedo dosemeters simultaneously exposed. Irradiation tests on a ISO slab phantom were performed in reference neutron fields at IRSN-Cadarache. A relation was found between the response of the CR-39 or albedo dosemeter and the CR-39/albedo quotient, allowing to correct the reading of each dosemeter. The algorithm was tested in realistic neutron fields of Spanish nuclear power plants, where the energy distribution is known from BSS measurements. The satisfactory results allow proposing the CR-39/TLD-albedo double dosemeter to improve the accuracy of the dose evaluation procedure in the fast neutron individual monitoring. (author)
Eurados trial performance test for personal dosemeters for external beta radiation
DEFF Research Database (Denmark)
Christensen, P.; Bordy, J.M.; Ambrosi, P.;
On the initiative of the European Dosimetry Group (EURADOS) action group 'Harmonisation and Dosimetric Quality Assurance in Individual Monitoring for External Radiation' a trial performance test for whole-body and extremity personal dosemeters broadly representative of those in use in the EU was...... accomplished, This paper deals with the part of the performance test concerned with exposure to beta radiation. Fifteen dosimetric services participated with whole-body dosemeters intended to measure beta doses (H-p(0.07)) of which 13 used thermoluminescent (TL) detectors and two used photographic films. Eight...
Type testing of personal dosemeters for photon energy and angular response
DEFF Research Database (Denmark)
Julius, H.W.; Marshall, T.O.; Christensen, Poul;
Performance criteria for personal dosemeters have been recently proposed in the CEC document 'Technical Recommendations for Monitoring Individuals Occupationally Exposed to External Radiation' (EUR 5287, Revised). The current experiment was carried out to demonstrate that TLD-based dosimetry...... systems can comply with these requirements. The emphasis of the experiment was on the dosemeter response as a function of photon energy and angle of incidence of the radiation. The tests were based on the ICRU operational quantities H(p) (0.07) and H(p) (10). All measurements were compared with the true...
Characterisation of the Plasmodium falciparum Hsp70-Hsp90 organising protein (PfHop).
Gitau, Grace W; Mandal, Pradipta; Blatch, Gregory L; Przyborski, Jude; Shonhai, Addmore
Malaria is caused by Plasmodium species, whose transmission to vertebrate hosts is facilitated by mosquito vectors. The transition from the cold blooded mosquito vector to the host represents physiological stress to the parasite, and additionally malaria blood stage infection is characterised by intense fever periods. In recent years, it has become clear that heat shock proteins play an essential role during the parasite's life cycle. Plasmodium falciparum expresses two prominent heat shock proteins: heat shock protein 70 (PfHsp70) and heat shock protein 90 (PfHsp90). Both of these proteins have been implicated in the development and pathogenesis of malaria. In eukaryotes, Hsp70 and Hsp90 proteins are functionally linked by an essential adaptor protein known as the Hsp70-Hsp90 organising protein (Hop). In this study, recombinant P. falciparum Hop (PfHop) was heterologously produced in E. coli and purified by nickel affinity chromatography. Using specific anti-PfHop antisera, the expression and localisation of PfHop in P. falciparum was investigated. PfHop was shown to co-localise with PfHsp70 and PfHsp90 in parasites at the trophozoite stage. Gel filtration and co-immunoprecipitation experiments suggested that PfHop was present in a complex together with PfHsp70 and PfHsp90. The association of PfHop with both PfHsp70 and PfHsp90 suggests that this protein may mediate the functional interaction between the two chaperones.
Plasmodium falciparum Hsp70-z, an Hsp110 homologue, exhibits independent chaperone activity and interacts with Hsp70-1 in a nucleotide-dependent fashion.
Zininga, Tawanda; Achilonu, Ikechukwu; Hoppe, Heinrich; Prinsloo, Earl; Dirr, Heini W; Shonhai, Addmore
The role of molecular chaperones, among them heat shock proteins (Hsps), in the development of malaria parasites has been well documented. Hsp70s are molecular chaperones that facilitate protein folding. Hsp70 proteins are composed of an N-terminal nucleotide binding domain (NBD), which confers them with ATPase activity and a C-terminal substrate binding domain (SBD). In the ADP-bound state, Hsp70 possesses high affinity for substrate and releases the folded substrate when it is bound to ATP. The two domains are connected by a conserved linker segment. Hsp110 proteins possess an extended lid segment, a feature that distinguishes them from canonical Hsp70s. Plasmodium falciparum Hsp70-z (PfHsp70-z) is a member of the Hsp110 family of Hsp70-like proteins. PfHsp70-z is essential for survival of malaria parasites and is thought to play an important role as a molecular chaperone and nucleotide exchange factor of its cytosolic canonical Hsp70 counterpart, PfHsp70-1. Unlike PfHsp70-1 whose functions are fairly well established, the structure-function features of PfHsp70-z remain to be fully elucidated. In the current study, we established that PfHsp70-z possesses independent chaperone activity. In fact, PfHsp70-z appears to be marginally more effective in suppressing protein aggregation than its cytosol-localized partner, PfHsp70-1. Furthermore, based on coimmunoaffinity chromatography and surface plasmon resonance analyses, PfHsp70-z associated with PfHsp70-1 in a nucleotide-dependent fashion. Our findings suggest that besides serving as a molecular chaperone, PfHsp70-z could facilitate the nucleotide exchange function of PfHsp70-1. These dual functions explain why it is essential for parasite survival. PMID:26894764
Salivary Hsp72 does not track exercise stress and caffeine-stimulated plasma Hsp72 responses in humans
Fortes, Matthew B.; Whitham, Martin
Heat shock protein 72 (Hsp72) has been detected within saliva, and its presence may contribute to oral defence. It is currently unknown how physiological stress affects salivary Hsp72 or if salivary Hsp72 concentrations reflect plasma Hsp72 concentrations. We studied the effect of exercise upon salivary Hsp72 expression, and using caffeine administration, investigated the role of sympathetic stimulation upon salivary Hsp72 expression. Six healthy males performed two treadmill running exercise...
Sperm sorting procedure induces a redistribution of Hsp70 but not Hsp60 and Hsp90 in boar spermatozoa.
Spinaci, Marcella; Volpe, Sara; Bernardini, Chiara; de Ambrogi, Marco; Tamanini, Carlo; Seren, Eraldo; Galeati, Giovanna
Heat shock proteins, besides their protective function against stresses, have been recently indicated as key factors for sperm fertilizing ability. Since sexing sperm by high-speed flow-cytometry subjects them to different physical, mechanical, and chemical stresses, the present study was designed to verify, by immunofluorescence and Western blot, whether the sorting procedure induces any modification in the amount and cellular distribution of heat shock proteins 60, 70, and 90 (Hsp60, Hsp70, Hsp90). Immunolocalization and Western blot quantification of both Hsp60 and Hsp90 did not reveal differences between unsorted and sorted semen. On the contrary, a redistribution of Hsp70 immunoreactivity from the equatorial subsegment toward the equator of sperm cells was recorded after sorting; this relocation suggests capacitation-like changes of sperm membrane. This modification seems to be caused mainly by incubation with Hoechst 33342, while both passage of sperm through flow cytometer and laser beam represent only minor stimuli. A further Hsp70 redistribution seems to be due to the final steps of sperm sorting, charging, and deflection of drops, and to the dilution during collection. On the other hand, staining procedure and mechanical stress seem to be the factors most injurious to sperm viability. Moreover, Hsp70 relocation was deeply influenced by the storage method. In fact, storing sexed spermatozoa, after centrifugation, in a small volume in presence of seminal plasma induced a reversion of Hsp70 redistribution, while storage in the diluted catch fluid of collection tubes caused Hsp70 relocation in most sorted spermatozoa. PMID:16870948
Expression of stress response HSP70 gene in Asian paddle crabs, Charybdis japonica, exposure to endocrine disrupting chemicals, bisphenol A (BPA) and 4-nonylphenol (NP)
Park, Kiyun; Kwak, Ihn-Sil
The Asian paddle crab, Charybdis japonica, is a potential bio-indicator reflecting marine sediment toxicity as well as a commercially important species living along coastal areas in Korea. This study investigated its stress response by looking at the heat shock protein (HSP70) gene of C. japonica when the organism is exposed to bisphenol A (BPA) and 4-nonylphenol (NP). We characterized partial sequence of HSP70 as the stressresponse gene of C. japonica. The nucleotide sequence of C. japonica HSP70 is over 90% homologous with the corresponding gene of other crabs. Phylogenetic tree analysis revealed a close relationship between C. japonica HSP70 and HSP70 in other species of lobster and shrimps. HSP70 mRNA transcripts were detected in all the examined tissues of C. japonica, with the highest level in gills, the organ that most frequently came into contact with the external BPA or NP-laden water. As no reference data were available for C. japonica crab exposure, the BPA and NP 24-h LC50 values have not been previously determined. The expression of the C. japonica HSP70 gene to various BPA or NP concentrations during short and longer times was assessed. Gene expression was significantly induced in concentration- and time-dependent manners after BPA or NP exposures. These results support the postulation that crab C. japonica HSP70 could be a potential stress response molecular marker to monitor marine ecosystems.
EURADOS trial performance test for personal dosemeters for external beta radiation
International Nuclear Information System (INIS)
On the initiative of the European Dosimetry Group (EURADOS) action group 'Harmonisation and Dosimetric Quality Assurance in Individual Monitoring for External Radiation' a trial performance test for whole-body and extremity personal dosemeters broadly representative of those in use in the EU was accomplished. This paper deals with the part of the performance test concerned with exposure to beta radiation. Fifteen dosimetric services participated with whole-body dosemeters intended to measure beta doses (Hp(0.07)) of which 13 used thermoluminescent (TL) detectors and two used photographic films. Eight services participated with extremity dosemeters which all used TL detectors. A description is given of the irradiation set-up, the characteristics of the irradiation fields, the calibration quantity applied and the performance criteria used for the evaluation of the results. The paper discussed in detail the results obtained from the exercise. In particular, based on the replies to a questionnaire issued to each participant, the results are analysed in relation to important design characteristics of the dosemeters taking part in the test. (author)
A measurement of the response to fast neutrons of several materials dosemeters
International Nuclear Information System (INIS)
The response to fast neutrons was measured for three types of materials testing dosemeters: fast neutron dosimetry silicon diodes; beryllia, alumina and calcium fluoride TLDs; graphite walled ionisation chambers. The calibrations were made using a 3MW positive ion accelerator. The arrangement of the target, beam monitor and devices is described, and the measured fast neutron sensitivities are presented. (UK)
Future development of the demands on therapy dosemeters with ionization chambers
International Nuclear Information System (INIS)
Only little will change with the introduction of the European internal market with regard to the demands on ionization chamber dosemeters used in radiotherapy, provided that the harmonized standard is aligned with IEC publication 731. Type licences for domestic calibration will be replaced by European Communities licences. (orig.)
Development of an improved dosemeter for assessments of risk to the eye
International Nuclear Information System (INIS)
To develop an improved dosemeter to assess photon and beta exposures of the eye lens, and in response to issues surrounding the preferred values of Hlens to be used for guiding operational radiation protection, a programme of re-optimization of the current PHE thermoluminescence dosemeter has been performed. In particular, refinements of the filter located in front of the sensitive 7LiF:Mg,Cu,P element have been considered, so that the dose response characteristics of the device provide a better and more conservative estimate of risk. The investigation was performed using the Monte Carlo modelling software MCNP5, to produce a final design that featured a filter containing a 9.5 mm diameter polypropylene hemisphere truncated to a maximum thickness of 3.0 mm. The responses of this design in photon and electron fields are presented here, contrasted against those of the existing PHE eye dosemeter, with respect to the operational quantity Hp(3,E,θ) and both current and suggested values for the absorbed dose per fluence risk profile for the lens of the eye. - Highlights: • A programme of re-optimization of the current PHE eye dosemeter has been performed. • A design featuring a truncated hemispherical filter was found to be optimal. • The shape of the filter better resembles the rotational profile of the eye. • Response characteristics depend on the calibration conditions taken to provide the best risk estimate
Influence of dosemeter position for the assessment of eye lens dose during interventional cardiology
International Nuclear Information System (INIS)
The equivalent dose limit for the eye lens for occupational exposure recommended by the ICRP has been reduced to 20 mSv y-1 averaged over defined periods of 5 y, with no single year exceeding 50 mSv. The compliance with this new requirement could not be easy in some workplace such as interventional radiology and cardiology. The aim of this study is to evaluate different possible approaches in order to have a good estimate of the eye lens dose during interventional procedures. Measurements were performed with an X-ray system Philips Allura FD-10, using a PMMA phantom to simulate the patient scattered radiation and a Rando phantom to simulate the cardiologist. Thermoluminescence (TL) whole-body and TL eye lens dosemeters together with Philips DoseAware active dosemeters were located on different positions of the Rando phantom to estimate the eye lens dose in typical cardiology procedures. The results show that, for the studied conditions, any of the analysed dosemeter positions are suitable for eye lens dose assessment. However, the centre of the thyroid collar and the left ear position provide a better estimate. Furthermore, in practice, improper use of the ceiling-suspended screen can produce partial protection of some parts of the body, and thus large differences between the measured doses and the actual exposure of the eye could arise if the dosemeter is not situated close to the eye. (authors)
Pleurotus sajor-caju HSP100 complements a thermotolerance defect in hsp104 mutant Saccharomyces cerevisiae
Indian Academy of Sciences (India)
Jin-Ohk Lee; Mi-Jeong Jeong; Tack-Ryun Kwon; Seung-Kon Lee; Myung-Ok Byun; Ill-Min Chung; Soo-Chul Park
A putative Hsp100 gene was cloned from the fungus Pleurotus sajor-caju. mRNA expression studies demonstrated that this gene (designated PsHsp100) is highly induced by high temperature, induced less strongly by exposure to ethanol, and not induced by drought or salinity. Heat shock induction is detectable at 37°C and reaches a maximum level at 42°C. PsHsp100 mRNAlevels sharply increased within 15 min of exposure to high temperature, and reached a maximum expression level at 2 h that was maintained for several hours. These results indicate that PsHsp100 could work at an early step in thermotolerance. To examine its function, PsHsp100 was transformed into a temperature-sensitive hsp104 deletion mutant Saccharomyces cerevisiae strain to test the hypothesis that PsHSP100 is an protein that functions in thermotolerance. Overexpression of PsHSP100 complemented the thermotolerance defect of the hsp104 mutant yeast, allowing them survive even at 50°C for 4 h. These results indicate that PsHSP100 protein is functional as an HSP100 in yeast and could play an important role in thermotolerance in P. sajor-caju.
Pleurotus sajor-caju HSP100 complements a thermotolerance defect in hsp104 mutant Saccharomyces cerevisiae
Indian Academy of Sciences (India)
Jin-Ohk Lee; Mi-Jeong Jeong; Tack-Ryun Kwon; Seung-Kon Lee; Myung-Ok Byun; Ill-Min Chung; Soo-Chul Park
A putative Hsp100 gene was cloned from the fungus Pleurotus sajor-caju. mRNA expression studies demonstrated that this gene (designated PsHsp100) is highly induced by high temperature, induced less strongly by exposure to ethanol, and not induced by drought or salinity. Heat shock induction is detectable at 37°C and reaches a maximum level at 42°C. PsHsp100 mRNAlevels sharply increased within 15 min of exposure to high temperature, and reached a maximum expression level at 2 h that was maintained for several hours. These results indicate that PsHsp100 could work at an early step in thermotolerance. To examine its function, PsHsp100 was transformed into a temperature-sensitive hsp104 deletion mutant Saccharomyces cerevisiae strain to test the hypothesis that PsHSP100 is an protein that functions in thermotolerance. Overexpression of PsHSP100 complemented the thermotolerance defect of the hsp104 mutant yeast, allowing them survive even at 50°C for 4 h. These results indicate that PsHSP100 protein is functional as an HSP100 in yeast and could play an important role in thermotolerance in P. sajor-caju.
Radiation burden to hands from handling 99Mo-sup(99m)Tc generators measured by UVVVR finger dosemeters
International Nuclear Information System (INIS)
The doses to the fingers of seven technicians carrying out elutions of the 99Mo-sup(99m)Tc generators were monitored using LiF RTL dosemeters placed on the volar sides of the thumb, the index and middle fingers, and aluminophosphate glass RTL dosemeters fixed to the dorsal or the volar side of the ring finger. The finger doses corresponded to 0.4 to 1.9% of the annual permissible dose to hands. The maximum value measured in one technician was 14.3 mGy at a whole-body dose of 1.8 mGy as measured by a film dosemeter. (Ha)
Calibration of a special neutron dosemeter based on solid-state track detectors and fission radiators in various neutron fields
International Nuclear Information System (INIS)
The calibration of a personnel neutron dosemeter in different neutron fields is described. The badge-like dosemeter contains 5 detectors: polycarbonate foil (10 μm, Makrofol KG), 232Th, natural uranium, natural uranium with boron, and natural uranium with cadmium. Detector sensitivity and calibration factors have been calculated and measured in radiation fields of 252Cf fission neutrons, WWR-S reactor neutrons with and without Cd and Fe shielding, 3-MeV (d,t) generator neutrons, and 238PuBe neutrons. Measurement range and achievable accuracy are discussed from the point of view of applying the dosemeter in routine and emergency uses
Hsp70 Forms Antiparallel Dimers Stabilized by Post-translational Modifications to Position Clients for Transfer to Hsp90
Directory of Open Access Journals (Sweden)
Nina Morgner
Full Text Available Protein folding in cells is regulated by networks of chaperones, including the heat shock protein 70 (Hsp70 system, which consists of the Hsp40 cochaperone and a nucleotide exchange factor. Hsp40 mediates complex formation between Hsp70 and client proteins prior to interaction with Hsp90. We used mass spectrometry (MS to monitor assemblies formed between eukaryotic Hsp90/Hsp70/Hsp40, Hop, p23, and a client protein, a fragment of the glucocorticoid receptor (GR. We found that Hsp40 promotes interactions between the client and Hsp70, and facilitates dimerization of monomeric Hsp70. This dimerization is antiparallel, stabilized by post-translational modifications (PTMs, and maintained in the stable heterohexameric client-loading complex Hsp902Hsp702HopGR identified here. Addition of p23 to this client-loading complex induces transfer of GR onto Hsp90 and leads to expulsion of Hop and Hsp70. Based on these results, we propose that Hsp70 antiparallel dimerization, stabilized by PTMs, positions the client for transfer from Hsp70 to Hsp90.
Heat shock proteins in Trypanosoma cruzi: identification and localization of HSP70 and HSP60 proteins and structure of HSP60 genes (brief report).
de Marval, M G; Souto-Padron, T; Gottesdiener, K; Silva, R; van der Ploeg, L H; Rondinelli, E
To identify the members of the HSP70 and HSP60 families of Trypanosoma cruzi, we analysed 35S methionine epimastigote cells by two dimensional Western blot. At 29 degrees C, an HSP70 monoclonal antibody (anti-D. melanogaster) recognized eight isotypes. At least five of these were heat-induced. Polyclonal antibody against the 65 KDa antigen (anti-M. tuberculosis) recognized three isotypes with identical molecular weights, but different microliters. Only one isoform was heat induced. The cellular distribution of HSP70 and HSP60 was studied by immunoelectron microscopy. Anti-HSP70 reactive protein was localized in the cytoplasm, mitochondria and nucleus, while anti-HSP60 protein was found in the mitochondrion and in close association with the kinetoplast. To characterize the HSP60 gene and its proteins, we isolated a genomic T. cruzi clone encoding the HSP60 gene. T. cruzi HSP60 genes could be shown to be organized in 2100 nt tandem arrays. RELP in the HSP60 genes revealed that at least three different types of HSP60 genes were encoded in the T cruzi genome. The predicted open reading frame measured exhibits about 50% identity to other HSP60 described. Expression of these HSP60 genes could not be induced by 2 hours heat shock at 37 degrees C. Post-transcriptional mechanisms may be responsible for HSP60 induction in T. cruzi. PMID:7670543
Performance of a PADC personal neutron dosemeter at simulated and real workplace fields of the nuclear industry
International Nuclear Information System (INIS)
In the framework of the EVIDOS (Evaluation of Individual Dosimetry in Mixed Neutron and Photon Radiation Fields) project, funded by the EC, measurements with PADC personal neutron dosemeters were carried out at several workplace fields of the nuclear industry and at simulated workplace fields. The measured personal neutron dose equivalents of the PADC personal neutron dosemeter are compared with values that were assessed within the EVIDOS project by other partners. The detection limits for different spectra types are given. In cases were the neutron dose was too low to be measured by the PADC personal neutron dosemeter, the response is estimated by convoluting the responses to monoenergetic neutrons with the dose energy distribution measured within EVIDOS. The advantages and limitations of the PADC personal neutron dosemeter are discussed. (authors)
Use of a robotic manipulator in the simulation of the automation of a calibration process of dosemeters
International Nuclear Information System (INIS)
The development of a system based in a manipulative robot which simulates the operative sequence in a calibration process of dosemeters is presented. In this process it is performed the monitoring of the dosemeter positions and the calibrator by mean of an arm of articulated robot which develops the movement sequences and the taking a decision based on the information coming from the external sensors. (Author)
Echinococcus granulosus: in vitro effects of ivermectin and praziquantel on hsp60 and hsp70 levels.
Martinez, J; Perez-Serrano, J; Bernadina, W E; Rodriguez-Caabeiro, F
Martinez, J., Perez-Serrano, J., Bernadina, W. E., Rodriguez-Caabeiro, F. 1999 Echinococcus granulosus: In vitro effects of ivermectin and praziquantel on hsp60 and hsp70 levels. Experimental Parasitology93, 171-180. Organisms or cells exposed to injurious stresses such as heat shock or chemicals respond by increased (or altered) expression of heat-shock proteins (HSPs). Conversely, an earlier exposure to stress can prepare cells to cope with a subsequent more severe stress. In the present study, protoscolices of Echinococcus granulosus were subjected to several anthelmintic treatments, involving storage of the protoscolices for 18, 30, and 50 h with 0.1 mg/ml of ivermectin (IV), praziquantel (PZ), and a combination of each with albendazole (ALB). The organisms were analyzed for the effects of drug treatment on cell integrity and on levels of hsp60 and hsp70 production. Drug efficacy was evaluated by microscopy and by protein content measurement. Hsp60 and hsp70 were detected by Western blotting and incubation with anti-hsp60 and anti-hsp70 antibody, respectively, and quantitation of these proteins was obtained using image analysis. Incubation with IV alone produced the most damage to the protoscolices as indicated by viability loss, decreased protein content, and altered hsp60 and hsp70 levels; incubation with IV + ALB produced less damage as manifested by fewer changes in the aforementioned damage parameters but PZ and PZ + ALB, in this context, were poor anthelmintics. Exposure of protoscolices to thermal stress prior to anthelmintic treatment, in most cases, increased drug efficacy. It is concluded that in the E. granulosus model system drug efficacy is associated with decreased levels of hsp70 expression and increased levels of hsp60 expression.
Structure of the Hsp110:Hsc70 Nucleotide Exchange Machine
Schuermann, Jonathan P.; Jiang, Jianwen; Cuellar, Jorge; Llorca, Oscar; Wang, Liping; Gimenez, Luis E.; Jin, Suping; Taylor, Alexander B.; Demeler, Borries; Morano, Kevin A.; Hart, P. John; Valpuesta, Jose M.; Lafer, Eileen M.; Sousa, Rui
Hsp70s mediate protein folding, translocation, and macromolecular complex remodeling reactions. Their activities are regulated by proteins that exchange ADP for ATP from the nucleotide-binding domain (NBD) of the Hsp70. These nucleotide exchange factors (NEFs) include the Hsp110s, which are themselves members of the Hsp70 family. We report the structure of an Hsp110:Hsc70 nucleotide exchange complex. The complex is characterized by extensive protein:protein interactions and symmetric bridging...
Sulfatide-Hsp70 Interaction Promotes Hsp70 Clustering and Stabilizes Binding to Unfolded Protein
Directory of Open Access Journals (Sweden)
Yoichiro Harada
Full Text Available The 70-kDa heat shock protein (Hsp70, one of the major stress-inducible molecular chaperones, is localized not only in the cytosol, but also in extracellular milieu in mammals. Hsp70 interacts with various cell surface glycolipids including sulfatide (3'-sulfogalactosphingolipid. However, the molecular mechanism, as well as the biological relevance, underlying the glycolipid-Hsp70 interaction is unknown. Here we report that sulfatide promotes Hsp70 oligomerization through the N-terminal ATPase domain, which stabilizes the binding of Hsp70 to unfolded protein in vitro. We find that the Hsp70 oligomer has apparent molecular masses ranging from 440 kDa to greater than 669 kDa. The C-terminal peptide-binding domain is dispensable for the sulfatide-induced oligomer formation. The oligomer formation is impaired in the presence of ATP, while the Hsp70 oligomer, once formed, is unable to bind to ATP. These results suggest that sulfatide locks Hsp70 in a high-affinity state to unfolded proteins by clustering the peptide-binding domain and blocking the binding to ATP that induces the dissociation of Hsp70 from protein substrates.
Heat shock protein genes (hsp20, hsp75 and hsp90) from Pieris rapae: Molecular cloning and transcription in response to parasitization by Pteromalus puparum
Institute of Scientific and Technical Information of China (English)
Jia-Ying Zhu; Guo-Xing Wu; Gong-Yin Ye; Cui Hu
Most molecular work on the roles of heat shock proteins (hsps) in host-parasite interaction has focused on vertebrates,rather than invertebrates.Here the full length complementary DNA (cDNA) sequences of three hsp genes (hsp20,hsp75 and hsp90)were amplified from Pieris rapae,and their transcriptional responsiveness to parasitization by the endoparasitic wasp Pteromalus puparum were investigated.The cDNA sequence analysis of hsp20,hsp75 and hsp90 revealed open reading frames of 531,2 328 and 2 157 bp in length,which encode proteins with calculated molecular weights of 19.5,75.48 and 82.7 kDa,respectively.The comparison of amino acid sequences showed that P.rapae hsp20 shared highly divergent homology to that of other insects,while hsp75 and hsp90 showed high homology to their counterparts of other species.The expression analysis indicated that these three genes were influenced in response to parasitization by P.puparum.The hsp20 transcripts in parasitized pupae were higher compared to nonparasitized pupae.The expression of hsp75 and hsp90 were down-regulated following parasitization.The results indicate that hsps are involved in host-parasitoid interactions.
Abnormal interaction of motor neuropathy-associated mutant HspB8 (Hsp22) forms with the RNA helicase Ddx20 (gemin3)
Sun, Xiankui; Fontaine, Jean-Marc; Hoppe, Adam D.; Carra, Serena; DeGuzman, Cheryl; Martin, Jody L.; Simon, Stephanie; Vicart, Patrick; Welsh, Michael J.; Landry, Jacques; Benndorf, Rainer
A number of missense mutations in the two related small heat shock proteins HspB8 (Hsp22) and HspB1 (Hsp27) have been associated with the inherited motor neuron diseases (MND) distal hereditary motor neuropathy and Charcot-Marie-Tooth disease. HspB8 and HspB1 interact with each other, suggesting tha
Measurement models for passive dosemeters in view of uncertainty evaluation using the Monte Carlo method.
van Dijk, J W E
Two measurement models for passive dosemeters such as thermoluminescent dosemeter, optically stimulated luminescence, radio-photoluminescence, photographic film or track etch are discussed. The first model considers the dose evaluation with the reading equipment as a single measurement, the one-stage model. The second model considers the build-up of a latent signal or latent image in the detector during exposure and the evaluation using a reader system as two separate measurements, the two-stage model. It is discussed that the two-stage model better reflects the cause and effect relations and the course of events in the daily practice of a routine dosimetry service. The one-stage model will be non-linear in crucial input quantities which can give rise to erroneous behavior of the uncertainty evaluation based on the law of propagation of uncertainty. Input quantities that show an asymmetric probability distributions propagate through the one-stage model in a physically not relevant way.
Monitoring radiation dose to the hands in nuclear medicine: location of dosemeters
International Nuclear Information System (INIS)
The relatively high radiation dose which can be received by the hands of staff in nuclear medicine departments means that in many departments it is necessary to monitor such doses. A convenient method is to use a TLD sachet in a plastic strip around a finger. This study was done to determine whether a dosemeter worn at the base of the middle finger was adequate to monitor the dose to the surface of the whole hand. Dosemeters were worn at the finger tips, finger base and palm of both hands, on two people while preparing and dispensing radiopharmaceuticals, and two others while giving injections using syringe shields. The pattern of distribution of radiation dose to the hands was similar for all workers and for both types of work. A single, convenient site (base of middle finger) may therefore be used for monitoring radiation dose to the hand. (author)
Application of TL dosemeters for dose distribution measurements at high temperatures in nuclear reactors.
Osvay, M; Deme, S
Al2O3:Mg,Y ceramic thermoluminescence dosemeters were developed at the Institute of Isotopes for high dose applications at room temperatures. The glow curve of Al2O3:Mg,Y exhibits two peaks--one at 250 degrees C (I) and another peak at approximately 400 degrees C (II). In order to extend the application of these dosemeters to high temperatures, the effect of irradiation temperature was investigated using temperature controlled heating system during high dose irradiation at various temperatures (20-100 degrees C). The new calibration and measuring method has been successfully applied for dose mapping within the hermetic zone of the Paks Nuclear Power Plant even at high temperature parts of blocks.
Exposure levels to radiation in a nuclear medicine laboratory: measurements with thermoluminescence dosemeters
International Nuclear Information System (INIS)
Since 1996 in the Nuclear medicine Department and another routine and research departments of the National Institute of Medical and Nutrition Sciences (INCMNSZ) are working at least with 12 radioactive sources opened and sealed. However, it was unknown if with the Tl personal dosemeters with lithium fluoride crystals (LiF), could be possible to receive information about the equivalent dose for each radionuclide or if there was some radionuclide that by being low energy emissor or beta energy emissor, it did not represent an ionization power sufficient to excite the crystals of the thermoluminescent dosemeters (DTL). In this work the obtained results with control dosemeters of diverse source opened or sealed are shown, which were put at 1 cm of the LiF crystals during a time exposure 18 hours. Therefore the objective of this work is to verify which sources excite or not to DTL crystals and taking the pertinent safety measures for each radionuclide. The conclusion is that the majority of dosemeters were excited by beta or gamma radiation of the radionuclides and that LiF crystals are able to receive equivalent doses until 1200 mSv, being this a guarantee for the staff, that in an any moment could be exposed to high dose in his working day. Also it was corroborated that the radionuclides more energizer are: iodine-131, iodine-125 and sodium-22 while the phosphorus-32 must be managed with careful, since the exposure to hands can result significant, just like the technetium-99m (99m Tc). (Author)
Determination of the dose index in computerized tomography using thermoluminescent dosemeters
International Nuclear Information System (INIS)
In this work the obtained results of the determination of the dose index are presented in thorax studies in computed tomography and helical tomography carried out in Mexico using thermoluminescent dosemeters of LiF: Mg,Cu,P + Ptfe developed and manufactured in our country. The results showed that under similar conditions of irradiation and operation (pitch = 1), significant differences don't exist among the doses absorbed measures in the phantom due to the two types of used tomographs. (Author)
ENEA extremity dosemeter based on LiF(Mg,Cu,P) to evaluate Hp(3,alpha).
Mariotti, F; Fantuzzi, E; Morelli, B; Gualdrini, G; Botta, M C; Uleri, G; Bordy, J M; Denoziere, M
Recent epidemiological studies suggest a rather low-dose threshold (ORAMED) Project, whose WP2 is aimed at the quantity H(p)(3) and eye lens dosimetry in practice, are taken into account. The paper summarises the main aspects of the study carried out at ENEA-Radiation Protection Institute (Bologna, Italy) to provide practical solutions (in the use and the design) to evaluate the response of the ENEA TL extremity dosemeter in terms of H(p)(3).
Silva, E H; Knežević, Ž; Struelens, L; Covens, P; Ueno, S; Vanhavere, F; Buls, N
Recent studies demonstrated that lens opacities can occur at lower radiation doses than previously accepted. In view of these studies, the International Commission of Radiological Protection recommended in 2011 to reduce the eye lens dose limit from 150 mSv/y to 20 mSv/y. This implies in the need of monitoring doses received by the eye lenses. In this study, small rod radiophotoluminescent glass dosemeters (GD-300 series; AGC, Japan) were characterized in terms of their energy (ISO 4037 X-rays narrow spectrum series, S-Cs and S-Co) and angular dependence (0 up to 90 degrees, with 2 ISO energies: N-60 and S-Cs). All acquisitions were performed at SCK•CEN-Belgium, using the ORAMED proposed cylindrical phantom. For selected energies (N-60, N-80, N-100, N-120 and N-250), the response of dosemeters irradiated on the ISO water slab phantom, at the Ruđer Bošković Institute-Croatia, was compared to those irradiated on the cylindrical phantom. GD-300 series showed good energy dependence, relative to S-Cs, on the cylindrical phantom. From 0 up to 45 degrees, the dosemeters showed no significant angular dependence, regardless whether they were tested when placed vertically or horizontally on the cylindrical phantom. However, at higher angles, some angular dependence was observed, mainly when the dosemeters were irradiated with low-energy photons (N-60). Results showed that GD-300 series have good properties related to Hp(3), although some improvements may be necessary.
Hsp90: Friends, clients and natural foes.
Verma, Sharad; Goyal, Sukriti; Jamal, Salma; Singh, Aditi; Grover, Abhinav
Hsp90, a homodimeric ATPase, is responsible for the correct folding of a number of newly synthesized polypeptides in addition to the correct folding of denatured/misfolded client proteins. It requires several co-chaperones and other partner proteins for chaperone activity. Due to the involvement of Hsp90-dependent client proteins in a variety of oncogenic signaling pathways, Hsp90 inhibition has emerged as one of the leading strategies for anticancer chemotherapeutics. Most of Hsp90 inhibitors blocks the N terminal ATP binding pocket and prevents the conformational changes which are essential for the loading of co-chaperones and client proteins. Several other inhibitors have also been reported which disrupt chaperone cycle in ways other than binding to N terminal ATP binding pocket. The Hsp90 inhibition is associated with heat shock response, mediated by HSF-1, to overcome the loss of Hsp90 and sustain cell survival. This review is an attempt to give an over view of all the important players of chaperone cycle. PMID:27295069
Hsp90: Friends, clients and natural foes.
Verma, Sharad; Goyal, Sukriti; Jamal, Salma; Singh, Aditi; Grover, Abhinav
Hsp90, a homodimeric ATPase, is responsible for the correct folding of a number of newly synthesized polypeptides in addition to the correct folding of denatured/misfolded client proteins. It requires several co-chaperones and other partner proteins for chaperone activity. Due to the involvement of Hsp90-dependent client proteins in a variety of oncogenic signaling pathways, Hsp90 inhibition has emerged as one of the leading strategies for anticancer chemotherapeutics. Most of Hsp90 inhibitors blocks the N terminal ATP binding pocket and prevents the conformational changes which are essential for the loading of co-chaperones and client proteins. Several other inhibitors have also been reported which disrupt chaperone cycle in ways other than binding to N terminal ATP binding pocket. The Hsp90 inhibition is associated with heat shock response, mediated by HSF-1, to overcome the loss of Hsp90 and sustain cell survival. This review is an attempt to give an over view of all the important players of chaperone cycle.
Muscle cell atrophy induced by HSP gene silencing was counteracted by HSP overexpression
Choi, Inho; Lee, Joo-Hee; Nikawa, Takeshi; Gwag, Taesik; Park, Kyoungsook; Park, Junsoo
Heat shock proteins (HSP), as molecular chaperones, are known to assist protein quality control under various stresses. Although overexpression of HSP70 was found to contribute to muscle size retention under an unloading condition, it remains largely unclarified whether muscle atrophy is induced by active suppression of HSP expression. In this study, we pre-treated Hsp70 siRNA to rat L6 cells for the HSP gene silencing, and determined myotube diameter, HSP72 expression and anabolic and catabolic signaling activities in the absence or presence of triterpene celastrol (CEL), the HSP70 inducer. Relative to a negative control (NC), muscle cell diameter was reduced 0.89-fold in the siRNA-treated group, increased 1.2-fold in the CEL-treated group and retained at the size of NC in the siRNA+CEL group. HSP72 expression was decreased 0.35-fold by siRNA whereas the level was increased 6- to 8-fold in the CEL and siRNA+CEL groups. Expression of FoxO3 and atrogin-1 was increased 1.8- to 4.8-fold by siRNA, which was abolished by CEL treatment. Finally, phosphorylation of Akt1, S6K and ERK1/2 was not affected by siRNA, but was elevated 2- to 6-fold in the CEL and siRNA+CEL groups. Taken together, HSP downregulation by Hsp gene silencing led to muscle cell atrophy principally via increases in catabolic activities and that such anti-atrophic effect was counteracted by HSP overexpression.
Stadtmann, H; Grimbergen, T W M; Figel, M; Romero, A M; McWhan, A F; Gärtner, C
The European Dosimetry Group (EURADOS) first started performing international intercomparisons for whole-body dosemeters for individual monitoring services in 1998. Since 2008, these whole-body intercomparisons have been performed on a regular basis. In this latest intercomparison (IC2014), 96 monitoring services from 35 countries (mostly European) participated with 112 dosimetry systems. Unlike in the previous intercomparisons, the whole registration, communication and data exchange process was handled by a new on-line platform. All dosemeter irradiations were carried out in the Seibersdorf accredited dosimetry laboratory. The irradiation plan consisted of nine irradiation setups with five different photon radiation qualities (S-Cs, S-Co, RQR7, W-80 and W-150) and two different angles of radiation incidence (0° and 60°). The paper describes and analyses the individual results for the personal dose equivalent quantities Hp(10) and if requested, Hp(0.07), for all participating systems and compares these results with the ISO 14146 'trumpet curve' performance criteria. The results show that 100 systems (89 % of all systems) do fulfil the general ISO 14146 performance criteria. This paper gives an overview on the performance of the participating individual monitoring services and the influence of the dosemeter type on the observed response values. PMID:26763903
Targeting Hsp90 in Non-Cancerous Maladies.
Woodford, Mark R; Dunn, Diana M; Ciciarelli, Joseph G; Beebe, Kristin; Neckers, Len; Mollapour, Mehdi
Heat shock protein-90 (Hsp90) is a molecular chaperone critical to the folding, stability and activity of over 200 client proteins including many responsible for tumor initiation, progression and metastasis. Hsp90 chaperone function is linked to its ATPase activity and Hsp90 inhibitors interfere with this activity, thereby making Hsp90 an attractive target for cancer therapy. Also post-translational modification (PTM) and co-chaperone proteins modulate Hsp90 function, providing additional targets for secondary inhibition. Recent reports have shown that pathogens utilize both their own Hsp90 and that of their host for the propagation of infectious elements. In this review we will summarize our current knowledge of Hsp90 structure and function in both the pathogen and the host. We will focus on the role of Hsp90 in viral and parasitic diseases and the potential beneficial application of Hsp90 inhibitors alone and in combination with disease-specific inhibitors.
The nucleotide exchange factors of Hsp70 molecular chaperone
Directory of Open Access Journals (Sweden)
Andreas eBracher
Full Text Available Molecular chaperones of the Hsp70 family form an important hub in the cellular protein folding networks in bacteria and eukaryotes, connecting translation with the downstream machineries of protein folding and degradation. The Hsp70 folding cycle is driven by two types of cochaperones: J-domain proteins stimulate ATP hydrolysis by Hsp70, while nucleotide exchange factors (NEFs promote replacement of Hsp70-bound ADP with ATP. Bacteria and organelles of bacterial origin have only one known NEF type for Hsp70, GrpE. In contrast, a large diversity of Hsp70 NEFs has been discovered in the eukaryotic cell. These NEFs belong to the Hsp110/Grp170, HspBP1/Sil1 and BAG domain protein families. In this short review we compare the structures and molecular mechanisms of nucleotide exchange factors for Hsp70 and discuss how these cochaperones contribute to protein folding and quality control in the cell.
Structural and functional studies of Leishmania braziliensis Hsp90.
Silva, K P; Seraphim, T V; Borges, J C
The ubiquitous Hsp90 is critical for protein homeostasis in the cells, stabilizing "client" proteins in a functional state. Hsp90 activity depends on its ability to bind and hydrolyze ATP, involving various conformational changes that are regulated by co-chaperones, posttranslational modifications and small molecules. Compounds like geldanamycin (GA) and radicicol inhibit the Hsp90 ATPase activity by occupying the ATP binding site, which can lead client protein to degradation and also inhibit cell growth and differentiation in protozoan parasites. Our goal was to produce the recombinant Hsp90 of Leishmania braziliensis (LbHsp90) and construct of its N-terminal (LbHsp90N) and N-domain and middle-domain (LbHsp90NM), which lacks the C-terminal dimerization domain, in order to understand how Hsp90 works in protozoa. The recombinant proteins were produced folded as attested by spectroscopy experiments. Hydrodynamic experiments revealed that LbHsp90N and LbHsp90NM behaved as elongated monomers while LbHsp90 is an elongated dimer. All proteins prevented the in vitro citrate synthase and malate dehydrogenase aggregation, attesting that they have chaperone activity, and interacted with adenosine ligands with similar dissociation constants. The LbHsp90 has low ATPase activity (k(cat)=0.320min(-1)) in agreement with Hsp90 orthologs, whereas the LbHsp90NM has negligible activity, suggesting the importance of the dimeric protein for this activity. The GA interacts with LbHsp90 and with its domain constructions with different affinities and also inhibits the LbHsp90 ATPase activity with an IC(50) of 0.7μM. All these results shed light on the LbHsp90 activity and are the first step to understanding the Hsp90 molecular chaperone system in L. braziliensis. PMID:22910377
Thermoluminescent response of dosemeters TLD-100 exposed to distinct baker protocols, irradiation and reading
International Nuclear Information System (INIS)
The interest that motivated the realization of this work is the opposing discrepancy among the values of the efficiency thermoluminescent of heavy charged particles (PCP) regarding gamma radiation (ηPCP, γ) reported in different works and gathered recently for Horowitz (Ho 01). The measures of relative thermoluminescent efficiency have importance in relation to the dosimetry associated to medical therapy with heavy charged particle. The measurement of ηPCP, γ depends of multiple experimental factors. To understand this dependence it was quantified the effect of using different procedures experimental in the estimate of the relative thermoluminescent efficiency of dosemeters TLD-100 (LiF: Ti; Mg) for protons of 3 MeV regarding gamma rays of 60Co (ηPCP, γ), varying the lot, the presentation, the one baked and the team reader. When was used the same global procedure values they were obtained for (ηPCP, γ) inside the interval [0.30, 0.58] for the peak 5 and [0.35, 0.76] for the total thermoluminescent signal (Tl). At the use different equipment, baked and lot are obtained maximum differences of 30%, 12% and 6% respectively in the values of (ηPCP, γ) for the peak 5, and 25%, 28% and 7% for the total Tl signal. The changes more significant of 36% and 44% for peak 5 and total signal respectively are obtained when changing the presentation of the dosemeter. As a complementary investigation it was studied the distribution of the Tl signal of each peak in the deconvolution of the curve of brightness with regard to the total signal in exposed dosemeters to high fluence of protons (1x1010 p/cm2) varying the experimental protocol. It was found that the distribution of the Tl signal has a difference of the order of 5% when changing the used reading team. It was observed that the contribution of the peak 5 regarding the total signal are preserved when changing baked and that it results to be 8% greater for the presentation in dosemeters of 1 x 1 x 1 mm3 that for
Detection of irradiation-induced, membrane heat shock protein 70 (Hsp70) in mouse tumors using Hsp70 Fab fragment
International Nuclear Information System (INIS)
Background and purpose: The major stress-inducible heat shock protein 70 (Hsp70) is frequently overexpressed in highly aggressive tumors, and elevated intracellular Hsp70 levels mediate protection against apoptosis. Following therapeutic intervention, such as ionizing irradiation, translocation of cytosolic Hsp70 to the plasma membrane is selectively increased in tumor cells and therefore, membrane Hsp70 might serve as a therapy-inducible, tumor-specific target structure. Materials and methods: Based on the IgG1 mouse monoclonal antibody (mAb) cmHsp70.1, we produced the Hsp70-specific recombinant Fab fragment (Hsp70 Fab), as an imaging tool for the detection of membrane Hsp70 positive tumor cells in vitro and in vivo. Results: The binding characteristics of Hsp70 Fab towards mouse colon (CT26) and pancreatic (1048) carcinoma cells at 4 deg. C were comparable to that of cmHsp70.1 mAb, as determined by flow cytometry. Following a temperature shift to 37 deg. C, Hsp70 Fab rapidly translocates into subcellular vesicles of mouse tumor cells. Furthermore, in tumor-bearing mice Cy5.5-conjugated Hsp70 Fab, but not unrelated IN-1 control Fab fragment (IN-1 ctrl Fab), gradually accumulates in CT26 tumors between 12 and 55 h after i.v. injection. Conclusions: In summary, the Hsp70 Fab provides an innovative, low immunogenic tool for imaging of membrane Hsp70 positive tumors, in vivo.
H p(0.07) photon dosemeters for eye lens dosimetry: Calibration on a rod vs. a slab phantom
International Nuclear Information System (INIS)
In recent years, several papers dealing with eye lens dosimetry have been published as epidemiological studies are implying that the induction of cataracts occurs even at eye lens doses of less than 500 mGy. For that reason, the necessity to monitor the eye lens may become more important than it was before. However, only few dosemeters for the appropriate quantity Hp(3) are available. Partial-body dosemeters are usually designed to measure the quantity Hp(0.07) calibrated on a rod phantom representing a finger while a slab phantom much better represents the head. Therefore, in this work it was investigated whether dosemeters designed for the quantity Hp(0.07) calibrated on a rod phantom can also be worn on the head (close to the eyes) and still deliver correct results (Hp(0.07) on a head). For that purpose, different types of partial-body dosemeters from routine use were irradiated at different photon energies on both a rod and a slab phantom. It turned out that their response values are within ±5% independent of the phantom if the quantity value for the respective phantom is used. Thus, partial-body dosemeters designed for the quantity Hp(0.07) calibrated on a rod phantom may be worn on the head and used to monitor the eye lens dose due to photon radiation via the measurement of Hp(0.07) on the head. (authors)
Hsp90 inhibition decreases mitochondrial protein turnover.
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Daciana H Margineantu
Full Text Available BACKGROUND: Cells treated with hsp90 inhibitors exhibit pleiotropic changes, including an expansion of the mitochondrial compartment, accompanied by mitochondrial fragmentation and condensed mitochondrial morphology, with ultimate compromise of mitochondrial integrity and apoptosis. FINDINGS: We identified several mitochondrial oxidative phosphorylation complex subunits, including several encoded by mtDNA, that are upregulated by hsp90 inhibitors, without corresponding changes in mRNA abundance. Post-transcriptional accumulation of mitochondrial proteins observed with hsp90 inhibitors is also seen in cells treated with proteasome inhibitors. Detailed studies of the OSCP subunit of mitochondrial F1F0-ATPase revealed the presence of mono- and polyubiquitinated OSCP in mitochondrial fractions. We demonstrate that processed OSCP undergoes retrotranslocation to a trypsin-sensitive form associated with the outer mitochondrial membrane. Inhibition of proteasome or hsp90 function results in accumulation of both correctly targeted and retrotranslocated mitochondrial OSCP. CONCLUSIONS: Cytosolic turnover of mitochondrial proteins demonstrates a novel connection between mitochondrial and cytosolic compartments through the ubiquitin-proteasome system. Analogous to defective protein folding in the endoplasmic reticulum, a mitochondrial unfolded protein response may play a role in the apoptotic effects of hsp90 and proteasome inhibitors.
Effective dose assessment in the maxillofacial region using thermoluminescent (TLD) and metal oxide semiconductor field-effect transistor (MOSFET) dosemeters: a comparative study
J. Koivisto; D. Schulze; J. Wolff; D. Rottke
Objectives: The objective of this study was to compare the performance of metal oxide semiconductor field-effect transistor (MOSFET) technology dosemeters with thermoluminescent dosemeters (TLDs) (TLD 100; Thermo Fisher Scientific, Waltham, MA) in the maxillofacial area. Methods: Organ and effective
Influence of the stem effect on radioluminescence signals from optical fibre Al2O3:C dosemeters
DEFF Research Database (Denmark)
Marckmann, C.J.; Aznar, M.C.; Andersen, C.E.;
This paper analyses the influence of the Cerenkov radiation and other noise sources, the so-called stem effect, on radioluminescence (RL) signals generated in optical fibre Al2O3:C dosemeters used in medical dosimetry. The optical fibre dosemeter consists of a sensitive Al2O3:C crystal coupled...
Could Upregulated Hsp70 Protein Compensate for the Hsp90-Silence-Induced Cell Death in Glioma Cells?
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Chinmay Munje
Full Text Available The molecular chaperone heat shock protein 90 alpha (Hsp90α has been recognized in various tumours including glioma. This pilot study using a proteomic approach analyses the downstream effects of Hsp90 inhibition using 17-allylamino-17-demethoxygeldanamycin (17AAG and a short hairpin RNA (shRNA oligonucleotide targeting hsp90α (shhsp90α in the U87-MG glioma cell line. Preliminary data coupled with bioinformatic analysis identified several known and unknown Hsp90 client proteins that demonstrated a change in their protein expression after Hsp90 inhibition, signifying an alteration in the canonical pathways of cell cycle progression, apoptosis, cell invasion, angiogenesis, and metastasis. Members of the glycolysis pathway were upregulated, demonstrating increased dependency on glycolysis for energy source by the treated glioma cells. Upregulated proteins also include Hsp70 and members of its family such as Hsp27 and gp96, thereby suggesting the role of Hsp90 co-chaperones in compensating for Hsp90 function after Hsp90 inhibition. Considering Hsp70's role in antiapoptosis, it was postulated that a combination therapy involving a multitarget approach could be carried out. Consequently inhibition of both Hsp90 and Hsp70 in U87-MG glioma cells resulted in 60% cell death indicating the importance of combination therapy for glioma therapeutics.
Molecular mechanisms of canalization: Hsp90 and beyond
Indian Academy of Sciences (India)
Neeraj Salathia; Christine Queitsch
The Hsp90 chaperone machine facilitates the maturation of a diverse set of 'client' proteins. Many of these Hsp90 clients are essential nodes in signal transduction pathways and regulatory circuits, accounting for the important role Hsp90 plays in organismal development and responses to the environment. Recent findings suggest a broader impact of the chaperone on phenotype: fully functional Hsp90 canalizes wild-type phenotypes by suppressing underlying genetic and epigenetic variation. This variation can be expressed upon challenging the Hsp90 machinery by environmental stress, genetic or pharmaceutical targeting of Hsp90. The existence of Hsp90-buffered genetic and epigenetic variation together with plausible release mechanisms has wide-ranging implication for phenotype and possibly evolutionary processes. Here, we discuss the role of Hsp90 in canalization and organismal plasticity, and highlight important questions for future experimental inquiry.
STAT3 interacts directly with Hsp90.
Prinsloo, Earl; Kramer, Adam H; Edkins, Adrienne L; Blatch, Gregory L
Heat shock protein 90 (Hsp90) functionally modulates signal transduction. The signal transducer and activator of transcription 3 (STAT3) mediates interleukin-6 family cytokine signaling. Aberrant activation and mutation of STAT3 is associated with oncogenesis and immune disorders, respectively. Hsp90 and STAT3 have previously been shown to colocalize and coimmunoprecipitate in common complexes. Surface plasmon resonance spectroscopy revealed a direct, high affinity specific interaction between recombinant Hsp90β and STAT3β in the presence and absence of adenosine triphosphate (ATP) in molar excess. Furthermore, comparative analysis using a phosphomimetic mutation at tyrosine 705 showed that the direct interaction appeared to favor neither unactivated nor activated STAT3. Destabilizing mutation of STAT3 at arginine residues 414/417 to alanine in the DNA-binding domain, previously shown to disrupt nuclear translocation in vivo, reduced interaction with a STAT3 DNA binding site oligonucleotide and Hsp90β in vitro, indicating that STAT3 requires a functional DNA-binding domain for full direct interaction with Hsp90. Site-directed mutagenesis of a mammalian STAT3-EGFP-N1 fusion construct at RR414/417 and subsequent transfection into human MCF7 epithelial breast cancer cells showed no impaired nuclear translocation when observed by confocal laser scanning microscopy. However, costaining for Hsp90α/β isoforms and colocalization analysis revealed a defined decrease in pixel-on-pixel colocalization compared with the wild-type confirming the requirement of the DNA-binding domain for high-affinity interaction. PMID:22271514
Hsp90 modulates CAG repeat instability in human cells
Mittelman, David; Sykoudis, Kristen; Hersh, Megan; Lin, Yunfu; Wilson, John H.
The Hsp90 molecular chaperone has been implicated as a contributor to evolution in several organisms by revealing cryptic variation that can yield dramatic phenotypes when the chaperone is diverted from its normal functions by environmental stress. In addition, as a cancer drug target, Hsp90 inhibition has been documented to sensitize cells to DNA-damaging agents, suggesting a function for Hsp90 in DNA repair. Here we explore the potential role of Hsp90 in modulating the stability of nucleoti...
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E. N. Sheleenkova
Full Text Available The article gives a comparative analysis of existing and newly developed thermoluminescent detectors DTG-4, TTLD-580, TLD-1011(TM and DTVS-01 and dosemeters MKD-A and MKD-B for the purposes of individual dosimetric control of skin and eye lens exposure to radiation. The dependence of sensitivity of different thermoluminescent dosemeters, designed for dose equivalents measurements in skin and eye lens on the type (photons and ȕ-particles and energy of radiation was determined experimentally. There are conclusions about the limits of applicability of existing detectors and dosemeters under different radiation exposure conditions. The article evaluates the possibility of different dosimeter use for specific radiation exposure conditions.
Performance of a personal neutron dosemeter based on direct ion storage at workplace fields in the nuclear industry
International Nuclear Information System (INIS)
In the framework of the EVIDOS project, funded by the EC, measurements were carried out using dosemeters, based on ionisation chambers with direct ion storage (DIS-N), at several workplace fields, namely, at a fuel processing plant, a boiling and a pressurised water reactor, and near transport and storage casks. The measurements and results obtained with the DIS-N in these workplaces, which are representative for the nuclear industry, are described in this study. Different dosemeter configurations of converter and shielding materials were considered. The results are compared with values for personal dose equivalent which were assessed within the EVIDOS project by other partners. The advantages and limitations of the DIS-N dosemeter are discussed. (authors)
Characteristics and performance of the Sunna high dose dosemeter using green photoluminescence and UV absorption readout methods
Energy Technology Data Exchange (ETDEWEB)
Miller, S.D.; Murphy, M.K.; Tinker, M.R.; Kovacs, A.; McLaughlin, W
Growth in the use of ionising radiation for medical sterilisation and the potential for wide-scale international food irradiation have created the need for robust, mass-producible, inexpensive, and highly accurate radiation dosemeters. The Sunna dosemeter, lithium fluoride injection-moulded in a polyethylene matrix, can be read out using either green photoluminescence or ultraviolet (UV) absorption. The Sunna dosemeter can be mass-produced inexpensively with high precision. Both the photoluminescent and the UV absorption reader are simple and inexpensive. Both methods of analysis display negligible humidity effects, minimal dose rate dependence, acceptable post-irradiation effects, and permit measurements with a precision of nearly 1% 1s. The UV method shows negligible irradiation temperature effects from -30 deg. C to +60 deg. C. The photoluminescence method shows negligible irradiation temperature effects above room temperature for sterilisation dose levels and above. The dosimetry characteristics of these two readout methods are presented along with performance data in commercial sterilisation facilities. (author)
Applications of the HSP-matrix
DEFF Research Database (Denmark)
Bjarnø, Ole-Christian
In this paper different applications of the HSP matrix are discussed. The HSP High Speed Product Management)is a new management model in which dimensions related to organisation, technology, product and market are integrated to create synergy and focus in relation to faster new product developmen....... It is shown, that the model can be used as an extension of the classic product portfolio tools, among which the most well-known are the boston Consulting Group's and McKinsey & Co.'s versions....
FS23 binds to the N-terminal domain of human Hsp90:A novel small inhibitor for Hsp90
Institute of Scientific and Technical Information of China (English)
李健; 石峰; 陈丹琦; 曹慧玲; 熊兵; 沈竞康; 何建华
The N-terminal domain of heat shock protein 90 (Hsp90N) is responsible for the catalytic activity of Hsp90. The reported inhibitors of Hsp90 bind to this domain and would inhibit tumor growth and progression. Here, we synthesized FS23, a small molecule inhibitor of hsp90 and collected X-ray diffraction data of the complex crystal of Hsp90-FS23. High resolution X-ray crystallography shows that FS23 interacted with Hsp90N at the nucleotide binding cleft, and this suggests that FS23 may complete with nucleotides to bind to Hsp90N. The crystal structure and the interaction between Hsp90N and FS23 suggest a rational basis for the design of novel antitumor drugs.
Targeting Hsp70: A possible therapy for cancer.
Kumar, Sanjay; Stokes, James; Singh, Udai P; Scissum Gunn, Karyn; Acharya, Arbind; Manne, Upender; Mishra, Manoj
In all organisms, heat-shock proteins (HSPs) provide an ancient defense system. These proteins act as molecular chaperones by assisting proper folding and refolding of misfolded proteins and aid in the elimination of old and damaged cells. HSPs include Hsp100, Hsp90, Hsp70, Hsp40, and small HSPs. Through its substrate-binding domains, Hsp70 interacts with wide spectrum of molecules, ranging from unfolded to natively folded and aggregated proteins, and provides cytoprotective role against various cellular stresses. Under pathophysiological conditions, the high expression of Hsp70 allows cells to survive with lethal injuries. Increased Hsp70, by interacting at several points on apoptotic signaling pathways, leads to inhibition of apoptosis. Elevated expression of Hsp70 in cancer cells may be responsible for tumorigenesis and for tumor progression by providing resistance to chemotherapy. In contrast, inhibition or knockdown of Hsp70 reduces the size of tumors and can cause their complete regression. Moreover, extracellular Hsp70 acts as an immunogen that participates in cross presentation of MHC-I molecules. The goals of this review are to examine the roles of Hsp70 in cancer and to present strategies targeting Hsp70 in the development of cancer therapeutics. PMID:26898980
Experience on evaluation of passive neutron dosemeters according to ISO 21909
International Nuclear Information System (INIS)
This paper presents experience, found problems and lessons learnt during the evaluations of various TLD and CR-39 passive neutron dosemeters according to ISO 21909. Recommendations for the standard, being currently in revision, are also discussed. The edition 2005 of ISO 21909 is a good first step for having an international standard for testing passive neutron dosimetry systems. However, this standard has many imperfections and this paper tried to bring up some of them. Experience and optimisation of the whole evaluation process according to this standard were also discussed. (author)
Nuclear HSP90 and HSP70 in COPD patients treated with formoterol or formoterol and corticosteroids
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Holownia A
Full Text Available Abstract Objective Heat shock proteins assist cellular protein folding and are required for the normal activity of steroid receptors. In this study we assessed nuclear HSP90 and HSP70 proteins and mRNA levels in cells isolated from induced sputum of chronic obstructive pulmonary disease patients treated for 4 weeks with formoterol (F or formoterol+budesonide (F/ICS. Methods Nuclear heat shock protein levels were assessed by Western blot and specific mRNAs were quantified in cell lysates using qRT-PCR. Results Both HSP90 and HSP70 protein levels were higher in the F/ICS-treated patients in comparison with the F-treated group (by 31%, P Conclusions It is possible that increased nuclear heat shock proteins may play a role in the attenuation of the response to glucocorticoids in COPD patients.
Developmental expression of Hsp90, Hsp70 and HSF during morphogenesis in the vetigastropod Haliotis asinina.
Gunter, Helen M; Degnan, Bernard M
Heat shock proteins (Hsps) have dual functions, participating in both the stress response and a broad range of developmental processes. At physiological temperatures, it has been demonstrated in deuterostomes (vertebrates) and ecdysozoans (insects) that Hsps are expressed in tissues that are undergoing differentiation and morphogenesis. Here we investigate the developmental expression of Hsp70, Hsp90 and their regulatory transcription factor heat shock transcription factor (HSF) in the marine gastropod Haliotis asinina, a representative of the 3rd major lineage of bilaterian animals, the Lophotrochozoa. HasHsp70, HasHsp90 and HasHSF are maternally expressed in H. asinina and are progressively restricted to the micromere lineage during cleavage. During larval morphogenesis, they are expressed in unique and overlapping patterns in the prototroch, foot, and mantle. Hsp expression peaked in these tissues during periods of cell differentiation and morphogenesis, returning to lower levels after morphogenesis was complete. These patterns of Hsp and HSF expression in H. asinina are akin to those observed in ecdysozoans and deuterostomes, with Hsps being activated in cells and tissues undergoing morphogenesis.
Expression of Helicobacter pylori Hsp60 protein and its immunogenicity
Institute of Scientific and Technical Information of China (English)
Yang Bai; Liang-Ren Li; Ji-De Wang; Ye Chen; Jian-Feng Jin; Zhao-Shan Zhang; Dian-Yuan Zhou; Ya-Li Zhang
AIM: To express Hsp60 protein of H pylori by a constructed vector and to evaluate its immunogenicity.METHODS: Hsp60 DNA was amplified by PCR and inserted into the prokaryotie expression vector pET-22b (+), which was transformed into BL21 (DE3) E. coli strain to express recombinant protein. Immunogenicity of expressed Hsp60 protein was evaluated with animal experiments.RESULTS: DNA sequence analysis showed Hsp60 DNA was the same as GenBank's research. Hsp60 recombinant protein accounted for 27.2 % of the total bacterial protein,and could be recognized by the serum from H pylori infected patients and Balb/c mice immunized with Hsp60 itself.CONCLUSION: Hsp60 recombinant protein might become a potential vaccine for controlling and treating H pylori infection.
Calibration of the IRD two-component TLD albedo neutron dosemeter in some moderated neutron fields
Energy Technology Data Exchange (ETDEWEB)
Freitas, Bruno M.; Silva, Ademir X. da, E-mail: email@example.com, E-mail: firstname.lastname@example.com [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Martins, Marcelo M.; Pereira, Walsan W.; Mauricio, Claudia L.P., E-mail: firstname.lastname@example.com, E-mail: email@example.com, E-mail: firstname.lastname@example.com [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)
In some stray neutron fields, like those found in practices involving the handling of radionuclide sources, the neutron calibration factor for albedo neutron dosemeter can vary widely compared to the factor for bare sources. This is the case for well logging, which is the area with the largest number of workers exposed to neutrons in Brazil. The companies employ routinely {sup 241}Am-Be neutron sources. The albedo response variation is mainly due to the presence of scattered and moderated neutrons. This paper studies the response variation of the two-component TLD albedo neutron dosemeter used in the neutron individual monitoring service of Instituto de Radioprotecao e Dosimetria, in different radionuclide neutron source beams. The neutron spectra were evaluated applying a Bonner sphere spectrometer with a {sup 6}LiI(Eu) detector in the Brazilian National Metrology Neutron Laboratory. Standard neutron sources of {sup 241}Am-Be and {sup 252}Cf were employed, besides {sup 238}Pu-Be. Measurements were also made with scattered and moderated neutron beams, including {sup 252}Cf(D{sub 2}O) reference spectrum, {sup 241}Am-Be moderated with paraffin and silicone and a thermal neutron flux facility. New neutron calibration factors, as a function of the incident to albedo neutron ratio, were proposed for use in the albedo algorithm for occupational fields where the primary neutron beam is one of those studied sources. (author)
Dosimetric monitoring by thermoluminescent dosemeters of employers working in ionizing radiation fields
International Nuclear Information System (INIS)
Radiation Protection Commission was established in the Ministry of Health and Environment as Regulatory Authority, organizes and supervises all activities related with radiation protection, as the license, inspection, dosemetric personal control, medical examination, radioactive waste management, etc. Actually in our country are exerting some activities, which intend to covert the principal tasks in the field of radiation protection. Such activities are dosemetric personnel control based on TLD, radioactive environmental monitoring, radioactive waste management, calibration of dosemetric equipment's, etc. This paper describes the realization of personnel monitoring by thermoluminescent dosemeters TLD - 100 chips and cards were furnished by IAEA some years ago. Various experiments to determine the dependence of the response of dosemeters versus dose and versus orientation, the fading and lower detectable dose. The personnel monitoring of workers that work in ionizing radiation field were in charge of Institute of Nuclear Physics (INP). Actually in Albania was established the personnel monitoring service for employers of INP, Oncological Centre, Nuclear Medicine Centre and some other nuclear units in Tirana city. On the near future year exists the possibility to extend personnel monitoring for all physicians and technicians of rontgendiagnostic units of Durres, Shkodra, Elbasan cities. (author). 4 refs, 2 tabs
Neutron dosimetry inside the containment building of Spanish nuclear power plants with PADC based dosemeters
International Nuclear Information System (INIS)
The Spanish Nuclear Safety Council (Consejo de Seguridad Nuclear, CSN) recommends performing neutron individual dose assignments at workplaces based on ambient dose equivalent measurements using area monitors and by estimating the amount of time that workers spend in the different monitored environments. In addition, some Spanish nuclear power plants estimate the neutron dose equivalent using albedo thermoluminescence dosemeters (TLD). In the period 2004-2006, our group, together with other research centers, participated in a project, funded by the CSN, with the support of the Spanish Nuclear Power Plants Association (UNESA), to investigate in situ which could be the best practical procedure for individual neutron dose monitoring in nuclear power plants. As part of this survey, several units of the UAB PADC based neutron dosemeter were exposed, on a methacrylate phantom simulating a human body, at four different places inside the containment building of the Asco I nuclear power plant. The influence of different types of calibration neutron fields is analysed and the dose equivalent for each point is estimated.
Altered Cross-Linking of HSP27 by Zerumbone as a Novel Strategy for Overcoming HSP27-Mediated Radioresistance
International Nuclear Information System (INIS)
Purpose: HSP27 or HSP25 negatively regulates apoptosis pathways after radiation or chemotherapeutic agents. Abrogation of HSP27 function may be a candidate target for overcoming radio- and chemoresistance. Methods and Materials: Zerumbone (ZER), a cytotoxic component isolated from Zingiber zerumbet smith. Clonogenic survival assay and flow cytometry after Annexin V staining were performed to determine in vitro sensitization effects of ZER with ionizing radiation. A nude mouse xenografting system was also applied to detect in vivo radiosensitizing effects of ZER. Results: ZER produced cross-linking of HSP27, which was dependent on inhibition of the monomeric form of HSP27. ZER was directly inserted between the disulfide bond in the HSP27 dimer and modified normal HSP27 dimerization. Pretreatment with ZER before radiation inhibited the binding affinity between HSP27 and apoptotic molecules, such as cytochrome c and PKCδ, and induced sensitization in vitro and in an in vivo xenografted nude mouse system. Structural analogs lacking only the carbonyl group in ZER, such as α-humulene (HUM) and 8-hydroxy-humulen (8-OH-HUM), did not affect normal cross-linking of HSP27 and did not induce radiosensitization. Conclusions: We suggest that altered cross-linking of HSP27 by ZER is a good strategy for abolishing HSP27-mediated resistance.
BIO 100 Course tutorial/ indigohelp
For more classes visit www.indigohelp.com BIO 100 Assignment: The Scientific Method BIO 100 Exercise: UNESCO Research BIO 100 CheckPoint: Living Organisms BIO 100 Assignment: PopEcoLab BIO 100 Assignment: Photosynthesis and Cellular Respiration BIO 100 Assignment: DemographyLab BIO 100 Final Project: UNESCO Paper BIO 100 CheckPoint: Theories of Biology BIO 100 Assignment: Pearson Lab Scavenger Hunt BIO 100 CheckPoint: Plants vs. Animals ...
Viability of the Fricke dosemeter doped with methylene blue; Viabilidade do dosimetro Fricke dopado com azul de metileno
Energy Technology Data Exchange (ETDEWEB)
Souza, V.L.B.; Santos, C.D.A.; Rodrigues, K.R.G.; Cunha, M.S.; Figueiredo, M.D.C.; Melo, R.T. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)
This work aims to find the possible utilization of the Fricke dosemeter doped with methylene blue (FMB) for the dosimetry of photodynamic therapy. The FMB was irradiated wit X rays and light emitted diodes demonstrating positive answers to the stimulus, being probably to be used for dosimetric objectives
In-vivo dosimetry in radiotherapy: a comparison of the response of semiconductor and thermoluminescence (TLD700) dosemeters
Energy Technology Data Exchange (ETDEWEB)
Vynckier, S. [Universite Catholique de Louvain, Brussels (Belgium). Cliniques Universitaires St. Luc; Greffe, J.L.; Loncol, T.; Vanneste, F.; Octave-Prignot, M.; Denis, J.M.; De Patoul, N.
Semiconductor dosemeters and thermoluminescence dosemeters were calibrated in view of in-vivo dosimetry. Their response in a 8 MV photon beam and the respective correction factors for the treatment conditions were systematically studied. A total of 249 entrance and exit measurements with this dual detector combination were performed, mainly for treatments of the head and neck region. The resulting entrance and exit doses were compared with the expected doses at these positions, calculated on basis of the treatment and patient parameters. The results at the entrance showed a value of 1.010 (2.8% for the ratio of the measured to the calculated dose by diodes, 1.013) 4.9% for the ratio of the measured to the calculated dose by TLD and 1.003 (3.6% for the ratio of the measured dose by TLD to diodes. With respect the exit dose, the results were 0.998) 4.9%, 1.016 (7.7% and 1.019) 7.0% respectively after correction for the heterogeneity`s. Although the standard deviation for the TLD dosemeters is systematically larger than the standard deviation for the diodes, it is concluded that both dosemeters will yield similar results for-in-vivo dosimetry, if utilized under the same conditions.
Rizk, C; Vanhavere, F
The personal dosimetry service at the Lebanese Atomic Energy Commission uses Harshaw 8814 cards with LiF:Mg,Ti detectors. The dosemeters are read in a Harshaw 6600 TLD reader. In the process of accreditation for the ISO 17025 standard((1)), different influence factors are investigated and the uncertainty has been determined. The Individual Monitoring Service Laboratory-LAEC reads the dosemeters once it receives them from the customer, and new cards are immediately given for the next wearing period. The wearing period is 2 months. The dosemeter results are reported to the customers without background subtraction. Both Hp(10) and Hp(0.07) are reported. For this paper, only the uncertainty on Hp(10) will be focussed. The following factors are taken into account for the uncertainty: calibration factor, dosemeter homogeneity and repeatability, energy and angular dependence, non-linearity, temperature dependence, etc. Also the detection limit was determined. One of the important factors is the correction for fading. This fading correction depends on the procedure used such as storage temperatures, the time-temperature profile of the read-out, pre-heat and annealing conditions. Pre- and post-irradiation fading curves were measured for a storage period up to 182 d at room temperature (15-25°C). The resulting final combined standard uncertainty on the reported doses is of the order of 24 % for doses of ∼1 mSv. PMID:26443544
Characterization of the Cardiac Overexpression of HSPB2 Reveals Mitochondrial and Myogenic Roles Supported by a Cardiac HspB2 Interactome.
Directory of Open Access Journals (Sweden)
Julianne H Grose
Full Text Available Small Heat Shock Proteins (sHSPs are molecular chaperones that transiently interact with other proteins, thereby assisting with quality control of proper protein folding and/or degradation. They are also recruited to protect cells from a variety of stresses in response to extreme heat, heavy metals, and oxidative-reductive stress. Although ten human sHSPs have been identified, their likely diverse biological functions remain an enigma in health and disease, and much less is known about non-redundant roles in selective cells and tissues. Herein, we set out to comprehensively characterize the cardiac-restricted Heat Shock Protein B-2 (HspB2, which exhibited ischemic cardioprotection in transgenic overexpressing mice including reduced infarct size and maintenance of ATP levels. Global yeast two-hybrid analysis using HspB2 (bait and a human cardiac library (prey coupled with co-immunoprecipitation studies for mitochondrial target validation revealed the first HspB2 "cardiac interactome" to contain many myofibril and mitochondrial-binding partners consistent with the overexpression phenotype. This interactome has been submitted to the Biological General Repository for Interaction Datasets (BioGRID. A related sHSP chaperone HspB5 had only partially overlapping binding partners, supporting specificity of the interactome as well as non-redundant roles reported for these sHSPs. Evidence that the cardiac yeast two-hybrid HspB2 interactome targets resident mitochondrial client proteins is consistent with the role of HspB2 in maintaining ATP levels and suggests new chaperone-dependent functions for metabolic homeostasis. One of the HspB2 targets, glyceraldehyde 3-phosphate dehydrogenase (GAPDH, has reported roles in HspB2 associated phenotypes including cardiac ATP production, mitochondrial function, and apoptosis, and was validated as a potential client protein of HspB2 through chaperone assays. From the clientele and phenotypes identified herein, it is
Characterization of the Cardiac Overexpression of HSPB2 Reveals Mitochondrial and Myogenic Roles Supported by a Cardiac HspB2 Interactome.
Grose, Julianne H; Langston, Kelsey; Wang, Xiaohui; Squires, Shayne; Mustafi, Soumyajit Banerjee; Hayes, Whitney; Neubert, Jonathan; Fischer, Susan K; Fasano, Matthew; Saunders, Gina Moore; Dai, Qiang; Christians, Elisabeth; Lewandowski, E Douglas; Ping, Peipei; Benjamin, Ivor J
Small Heat Shock Proteins (sHSPs) are molecular chaperones that transiently interact with other proteins, thereby assisting with quality control of proper protein folding and/or degradation. They are also recruited to protect cells from a variety of stresses in response to extreme heat, heavy metals, and oxidative-reductive stress. Although ten human sHSPs have been identified, their likely diverse biological functions remain an enigma in health and disease, and much less is known about non-redundant roles in selective cells and tissues. Herein, we set out to comprehensively characterize the cardiac-restricted Heat Shock Protein B-2 (HspB2), which exhibited ischemic cardioprotection in transgenic overexpressing mice including reduced infarct size and maintenance of ATP levels. Global yeast two-hybrid analysis using HspB2 (bait) and a human cardiac library (prey) coupled with co-immunoprecipitation studies for mitochondrial target validation revealed the first HspB2 "cardiac interactome" to contain many myofibril and mitochondrial-binding partners consistent with the overexpression phenotype. This interactome has been submitted to the Biological General Repository for Interaction Datasets (BioGRID). A related sHSP chaperone HspB5 had only partially overlapping binding partners, supporting specificity of the interactome as well as non-redundant roles reported for these sHSPs. Evidence that the cardiac yeast two-hybrid HspB2 interactome targets resident mitochondrial client proteins is consistent with the role of HspB2 in maintaining ATP levels and suggests new chaperone-dependent functions for metabolic homeostasis. One of the HspB2 targets, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), has reported roles in HspB2 associated phenotypes including cardiac ATP production, mitochondrial function, and apoptosis, and was validated as a potential client protein of HspB2 through chaperone assays. From the clientele and phenotypes identified herein, it is tempting to
MCNP simulation of the incident and Albedo neutron response of the IRD Albedo Neutron Dosemeter for {sup 241}Am-Be moderated sources
Energy Technology Data Exchange (ETDEWEB)
Freitas, Bruno M.; Martins, Marcelo M.; Mauricio, Claudia L.P.; Mauricio, Claudia L.P. da, E-mail: email@example.com [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Silva, Ademir X. [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear
The IRD TLD Albedo dosemeter measures both incident and albedo neutron component. The incident to Albedo ratio is used to take into account the energy dependence of its response. In this paper, the behavior of the IRD Albedo dosemeter response as a function of the incident to Albedo ratio for {sup 241}Am-Be sources was simulated to improve its algorithm. The simulation was performed in MCNPX transport code and presents a good agreement with experimental measurements. The results obtained in this work are very useful to improve the accuracy of the IRD Albedo dosemeter at real neutron workplace. (author)
MCNP simulation of the incident and Albedo neutron response of the IRD Albedo Neutron Dosemeter for 241Am-Be moderated sources
International Nuclear Information System (INIS)
The IRD TLD Albedo dosemeter measures both incident and albedo neutron component. The incident to Albedo ratio is used to take into account the energy dependence of its response. In this paper, the behavior of the IRD Albedo dosemeter response as a function of the incident to Albedo ratio for 241Am-Be sources was simulated to improve its algorithm. The simulation was performed in MCNPX transport code and presents a good agreement with experimental measurements. The results obtained in this work are very useful to improve the accuracy of the IRD Albedo dosemeter at real neutron workplace. (author)
The investigation of correspondence of indications of the albedo dosemeter DVGN-01 to personnel irradiation doses in the fields of neutron radiation at the JINR nuclear power installations
International Nuclear Information System (INIS)
The calculated results of the research correspondence of the indication of the individual albedo dosemeter DVGN-01 to the individual equivalent dose for neutrons Hp(10) and to the effective dose for neutrons Eeff in the neutron fields at the JINR Nuclear Power Installations (JNPI) at different geometries of irradiations are presented. It has been shown that the correction coefficients are required for specific estimation of doses by the dosemeter. The coefficients were calculated using the energy sensitivity curve of the dosemeter and the known neutron spectra at the JNPI. By using the correction factors the uncertainties of both doses would not exceed the limits given to the personnel according to standards
Improved Metabolic Control in Diabetes, HSP60, and Proinflammatory Mediators
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Claudio Blasi
Full Text Available The diabetes-atherosclerosis relationship remains to be fully defined. Repeated prolonged hyperglycemia, increased ROS production and endothelial dysfunction are important factors. One theory is that increased blood levels of heat shock protein (HSP60 are proinflammatory, through activation of innate immunity, and contribute to the progression of vascular disease. It was hypothesized that improvement of diabetes control in patients presenting with metabolic syndrome would lower HSP60, and anti-HSP60 antibody levels and decrease inflammatory markers. Paired sera of 17 Italian patients, before and after intensive treatment, were assayed for cytokines, HSP60 and anti-HSP60 antibodies. As expected, intensive treatment was associated with a decrease in HgbA1C (P<0.001 and BMI (P<0.001. After treatment, there was a significant decrease in IL-6 (P<0.05. HSP60 levels were before treatment −6.9+1.9, after treatment −7.1+2.0 ng/mL (P=ns. Overall HSP60 concentrations were lower than published reports. Anti-HSP60 antibody titers were high and did not decrease with treatment. In conclusion, improvement of diabetic control did not alter HSP60 concentrations or antiHSP60 antibody titers, but led to a reduction of IL-6 levels.
The Anti-inflammatory mechanisms of Hsp70
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Thiago J Borges
Full Text Available Immune responses to heat shock proteins (Hsp develop in virtually all inflammatory diseases; however, the significance of such responses is only now becoming clear. In experimental disease models, Hsp administration can prevent or arrest inflammatory damage, and in initial clinical trials in patients with chronic inflammatory diseases, Hsp peptides have been shown to promote the production of anti-inflammatory cytokines, indicating immunoregulatory potential of Hsp. Therefore, the presence of immune responses to Hsp in inflammatory diseases can be seen as an attempt of the immune system to correct the inflammatory condition. Hsp70 can modulate inflammatory responses in models of arthritis, colitis and graft rejection, and the mechanisms underlying this effect are now being elucidated. Incubation with microbial Hsp70 was seen to induce tolerogenic DCs and to promote a suppressive phenotype in myeloid-derived suppressor cells and monocytes. These DC could induce regulatory T cells (Tregs, independently of the antigens they presented. Some Hsp70 family members are associated with autophagy, leading to a preferential uploading of Hsp70 peptides in MHC class II molecules of stressed cells. Henceforth, conserved Hsp70 peptides may be presented in these situations and constitute targets of Tregs, contributing to downregulation of inflammation. Finally, an interfering effect in multiple intracellular inflammatory signaling pathways is also known for Hsp70. Altogether it seems attractive to use Hsp70, or its derivative peptides, for modulation of inflammation. This is a physiological immunotherapy approach, without the immediate necessity of defining disease specific auto-antigens. In this article, we present the evidence on anti-inflammatory effects of Hsp70 and discuss the need for experiments that will be crucial for the further exploration of the immuno-suppressive potential of this protein.
Hsp70/Hsp90 organising protein (hop): beyond interactions with chaperones and prion proteins.
Baindur-Hudson, Swati; Edkins, Adrienne L; Blatch, Gregory L
The Hsp70/Hsp90 organising protein (Hop), also known as stress-inducible protein 1 (STI1), has received considerable attention for diverse cellular functions in both healthy and diseased states. There is extensive evidence that intracellular Hop is a co-chaperone of the major chaperones Hsp70 and Hsp90, playing an important role in the productive folding of Hsp90 client proteins. Consequently, Hop is implicated in a number of key signalling pathways, including aberrant pathways leading to cancer. However, Hop is also secreted and it is now well established that Hop also serves as a receptor for the prion protein, PrP(C). The intracellular and extracellular forms of Hop most likely represent two different isoforms, although the molecular determinants of these divergent functions are yet to be identified. There is also a growing body of research that reports the involvement of Hop in cellular activities that appear independent of either chaperones or PrP(C). While Hop has been shown to have various cellular functions, its biological function remains elusive. However, recent knockout studies in mammals suggest that Hop has an important role in embryonic development. This review provides a critical overview of the latest molecular, cellular and biological research on Hop, critically evaluating its function in healthy systems and how this function is adapted in diseases states.
Identification of peptides in human Hsp20 and Hsp27 that possess molecular chaperone and anti-apoptotic activities
Nahomi, Rooban B.; DiMauro, Michael A.; Wang, Benlian; Nagaraj, Ram H.
Previous studies have identified peptides in the 'crystallin-domain' of the small heat-shock protein (sHSP) α-crystallin with chaperone and anti-apoptotic activities. We found that peptides in heat-shock protein Hsp20 (G71HFSVLLDVKHFSPEEIAVK91) and Hsp27 (D93RWRVSLDVNHFAPDELTVK113) with sequence homology to α-crystallin also have robust chaperone and anti-apoptotic activities. Both peptides inhibited hyperthermic and chemically induced aggregation of client proteins. The scrambled peptides of Hsp20 and Hsp27 showed no such effects. The chaperone activities of the peptides were better than those from αA- and αB-crystallin. HeLa cells took up the FITC-conjugated Hsp20 peptide and, when the cells were thermally stressed, the peptide was translocated from the cytoplasm to the nucleus. The two peptides inhibited apoptosis in HeLa cells by blocking cytochrome c release from the mitochondria and caspase-3 activation. We found that scrambling the last four amino acids in the two peptides (KAIV in Hsp20 and KTLV in Hsp27) made them unable to enter cells and ineffective against stress-induced apoptosis. Intraperitoneal injection of the peptides prevented sodium-selenite-induced cataract formation in rats by inhibiting protein aggregation and oxidative stress. Our study has identified peptides from Hsp20 and Hsp27 that may have therapeutic benefit in diseases where protein aggregation and apoptosis are contributing factors. PMID:25332102
Mps1 Mediated Phosphorylation of Hsp90 Confers Renal Cell Carcinoma Sensitivity and Selectivity to Hsp90 Inhibitors
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Mark R. Woodford
Full Text Available The molecular chaperone Hsp90 protects deregulated signaling proteins that are vital for tumor growth and survival. Tumors generally display sensitivity and selectivity toward Hsp90 inhibitors; however, the molecular mechanism underlying this phenotype remains undefined. We report that the mitotic checkpoint kinase Mps1 phosphorylates a conserved threonine residue in the amino-domain of Hsp90. This, in turn, regulates chaperone function by reducing Hsp90 ATPase activity while fostering Hsp90 association with kinase clients, including Mps1. Phosphorylation of Hsp90 is also essential for the mitotic checkpoint because it confers Mps1 stability and activity. We identified Cdc14 as the phosphatase that dephosphorylates Hsp90 and disrupts its interaction with Mps1. This causes Mps1 degradation, thus providing a mechanism for its inactivation. Finally, Hsp90 phosphorylation sensitizes cells to its inhibitors, and elevated Mps1 levels confer renal cell carcinoma selectivity to Hsp90 drugs. Mps1 expression level can potentially serve as a predictive indicator of tumor response to Hsp90 inhibitors.
The Malarial Exported PFA0660w Is an Hsp40 Co-Chaperone of PfHsp70-x.
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Michael O Daniyan
Full Text Available Plasmodium falciparum, the human pathogen responsible for the most dangerous malaria infection, survives and develops in mature erythrocytes through the export of proteins needed for remodelling of the host cell. Molecular chaperones of the heat shock protein (Hsp family are prominent members of the exportome, including a number of Hsp40s and a Hsp70. PFA0660w, a type II Hsp40, has been shown to be exported and possibly form a complex with PfHsp70-x in the infected erythrocyte cytosol. However, the chaperone properties of PFA0660w and its interaction with human and parasite Hsp70s are yet to be investigated. Recombinant PFA0660w was found to exist as a monomer in solution, and was able to significantly stimulate the ATPase activity of PfHsp70-x but not that of a second plasmodial Hsp70 (PfHsp70-1 or a human Hsp70 (HSPA1A, indicating a potential specific functional partnership with PfHsp70-x. Protein binding studies in the presence and absence of ATP suggested that the interaction of PFA0660w with PfHsp70-x most likely represented a co-chaperone/chaperone interaction. Also, PFA0660w alone produced a concentration-dependent suppression of rhodanese aggregation, demonstrating its chaperone properties. Overall, we have provided the first biochemical evidence for the possible role of PFA0660w as a chaperone and as co-chaperone of PfHsp70-x. We propose that these chaperones boost the chaperone power of the infected erythrocyte, enabling successful protein trafficking and folding, and thereby making a fundamental contribution to the pathology of malaria.
Molecular characterization of the Corynebacterium pseudotuberculosis hsp60-hsp10 operon, and evaluation of the immune response and protective efficacy induced by hsp60 DNA vaccination in mice
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Oliveira Sérgio C
Full Text Available Abstract Background Heat shock proteins (HSPs are important candidates for the development of vaccines because they are usually able to promote both humoral and cellular immune responses in mammals. We identified and characterized the hsp60-hsp10 bicistronic operon of the animal pathogen Corynebacterium pseudotuberculosis, a Gram-positive bacterium of the class Actinobacteria, which causes caseous lymphadenitis (CLA in small ruminants. Findings To construct the DNA vaccine, the hsp60 gene of C. pseudotuberculosis was cloned in a mammalian expression vector. BALB/c mice were immunized by intramuscular injection with the recombinant plasmid (pVAX1/hsp60. Conclusion This vaccination induced significant anti-hsp60 IgG, IgG1 and IgG2a isotype production. However, immunization with this DNA vaccine did not confer protective immunity.
The Complex Function of Hsp70 in Metastatic Cancer
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Kata Juhasz
Full Text Available Elevated expression of the inducible heat shock protein 70 (Hsp70 is known to correlate with poor prognosis in many cancers. Hsp70 confers survival advantage as well as resistance to chemotherapeutic agents, and promotes tumor cell invasion. At the same time, tumor-derived extracellular Hsp70 has been recognized as a "chaperokine", activating antitumor immunity. In this review we discuss localization dependent functions of Hsp70 in the context of invasive cancer. Understanding the molecular principles of metastasis formation steps, as well as interactions of the tumor cells with the microenvironment and the immune system is essential for fighting metastatic cancer. Although Hsp70 has been implicated in different steps of the metastatic process, the exact mechanisms of its action remain to be explored. Known and potential functions of Hsp70 in controlling or modulating of invasion and metastasis are discussed.
Reduced Hsp70 and Glutamine in Pediatric Severe Malaria Anemia
DEFF Research Database (Denmark)
Kempaiah, Prakasha; Dokladny, Karol; Karim, Zachary;
Severe malarial anemia [SMA, hemoglobin (Hb) 5.0 g/dL] is a leading cause of global morbidity and mortality among children residing in Plasmodium falciparum transmission regions. Exploration of molecular pathways through global gene expression profiling revealed that SMA was characterized...... in malaria pathogenesis is unexplored, we investigated Hsp70 and molecular pathways in children with SMA. Validation experiments revealed that leukocytic HSP70 transcripts were reduced in SMA relative to non-severe malaria, and that intraleukocytic hemozoin (PfHz) was associated with lower HSP70. HSP70....... Treatment of cultured peripheral blood mononuclear cells (PBMCs) with PfHz caused a time-dependent decrease in Hsp70 transcripts/protein, and NF-κB activation. Gln treatment of PBMCs overcame PfHz-induced suppression of HSP70 transcripts/protein, reduced NF-κB activation, and suppressed over...
Functional and structural analysis of maize hsp101 IRES.
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Augusto Samuel Jiménez-González
Full Text Available Maize heat shock protein of 101 KDa (HSP101 is essential for thermotolerance induction in this plant. The mRNA encoding this protein harbors an IRES element in the 5'UTR that mediates cap-independent translation initiation. In the current work it is demonstrated that hsp101 IRES comprises the entire 5'UTR sequence (150 nts, since deletion of 17 nucleotides from the 5' end decreased translation efficiency by 87% compared to the control sequence. RNA structure analysis of maize hsp101 IRES revealed the presence of three stem-loops toward its 5' end, whereas the remainder sequence contains a great proportion of unpaired nucleotides. Furthermore, HSP90 protein was identified by mass spectrometry as the protein preferentially associated with the maize hsp101 IRES. In addition, it has been found that eIFiso4G rather than eIF4G initiation factor mediates translation of the maize hsp101 mRNA.
Leptin regulation of Hsp60 impacts hypothalamic insulin signaling
Kleinridders, André; Lauritzen, Hans P.M.M.; Ussar, Siegfried; Christensen, Jane H.; Mori, Marcelo A.; Bross, Peter; Kahn, C. Ronald
Type 2 diabetes is characterized by insulin resistance and mitochondrial dysfunction in classical target tissues such as muscle, fat, and liver. Using a murine model of type 2 diabetes, we show that there is hypothalamic insulin resistance and mitochondrial dysfunction due to downregulation of the mitochondrial chaperone HSP60. HSP60 reduction in obese, diabetic mice was due to a lack of proper leptin signaling and was restored by leptin treatment. Knockdown of Hsp60 in a mouse hypothalamic c...
Hsp90 governs dispersion and drug resistance of fungal biofilms.
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Nicole Robbins
Full Text Available Fungal biofilms are a major cause of human mortality and are recalcitrant to most treatments due to intrinsic drug resistance. These complex communities of multiple cell types form on indwelling medical devices and their eradication often requires surgical removal of infected devices. Here we implicate the molecular chaperone Hsp90 as a key regulator of biofilm dispersion and drug resistance. We previously established that in the leading human fungal pathogen, Candida albicans, Hsp90 enables the emergence and maintenance of drug resistance in planktonic conditions by stabilizing the protein phosphatase calcineurin and MAPK Mkc1. Hsp90 also regulates temperature-dependent C. albicans morphogenesis through repression of cAMP-PKA signalling. Here we demonstrate that genetic depletion of Hsp90 reduced C. albicans biofilm growth and maturation in vitro and impaired dispersal of biofilm cells. Further, compromising Hsp90 function in vitro abrogated resistance of C. albicans biofilms to the most widely deployed class of antifungal drugs, the azoles. Depletion of Hsp90 led to reduction of calcineurin and Mkc1 in planktonic but not biofilm conditions, suggesting that Hsp90 regulates drug resistance through different mechanisms in these distinct cellular states. Reduction of Hsp90 levels led to a marked decrease in matrix glucan levels, providing a compelling mechanism through which Hsp90 might regulate biofilm azole resistance. Impairment of Hsp90 function genetically or pharmacologically transformed fluconazole from ineffectual to highly effective in eradicating biofilms in a rat venous catheter infection model. Finally, inhibition of Hsp90 reduced resistance of biofilms of the most lethal mould, Aspergillus fumigatus, to the newest class of antifungals to reach the clinic, the echinocandins. Thus, we establish a novel mechanism regulating biofilm drug resistance and dispersion and that targeting Hsp90 provides a much-needed strategy for improving
Oda, K; Nakayama, T; Umetani, K; Kajihara, M; Yamauchi, T
A novel technique for designing a radiator suitable for personal neutron dosemeter based on plastic track detector was discussed. A multi-layer structure has been proposed in the previous report, where the thicknesses of plural polyethylene (PE) layers and insensitive ones were determined by iterative calculations of double integral. In order to arrange this procedure and make it more systematic, unfolding calculation has been employed to estimate an ideal radiator containing an arbitrary hydrogen concentration. In the second step, realistic materials replaced it with consideration of minimisation of the layer number and commercial availability. A radiator consisting of three layers of PE, Upilex and Kapton sheets was finally designed, for which a deviation in the energy dependence between 0.1 and 20 MeV could be controlled within 18 %. An applicability of fluorescent nuclear track detector element has also been discussed. PMID:26378225
Measurement analysis using the Fricke dosemeter; Analise de medicoes com o dosimetro Fricke
Energy Technology Data Exchange (ETDEWEB)
Pedrosa, G.A.C. [Instituto Nacional de Metrologia (INMETRO), Rio de Janeiro, RJ (Brazil)], e-mail: firstname.lastname@example.com; Dantas, C.C. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear], e-mail: firstname.lastname@example.com; Campos, C.A. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)], e-mail: email@example.com
The Fricke dosemeter has been used for absolute determination of the radiation dose between 40 and 350 Gy for X-rays, Gamma rays and fast electrons energies. The great inconvenient of that dosimetric system is the impossibility of using for measurements of exposure or low dose rates. A Fricke dosimetry system was implanted at the Nuclear Sciences Regional Center (CRCN), in Recife, Pernambuco state, Brazil, for the determination of radiation doses for spectrometry and mass dosimetry with plasma source. The statistical analysis of the obtained results have shown that using the spectrometric method that system cna be used for maintenance of factors of CRCN standard calibrations and the dose assessment thru mail system of radiotherapy centers of the country.
Cosmic-radiation dosimetry using electronic personal dosemeter (EPD) at commercial aircraft altitude
International Nuclear Information System (INIS)
Electronic Personal Dosemeter (EPD) was examined for effectiveness in cosmic radiation dosimetry at aircraft altitude through the measurements in a Japan-US round trip. The EPD value (Hepd) of individual dose equivalent, penetrating, Hp(10), was considered to be almost equal the deep absorbed dose attributed to electrons at the aircraft altitude. By assuming the fractions and the effective quality factors for other components (muons, protons, and neutrons) based on model-calculation data, an empirical equation to estimate a conservative deep dose-equivalent at 5 cm-tissue depth, H(50), was given as H(50)=3.1 x Hepd. Estimated H(50) values in the international flights were 4.9 μSv h-1 from Tokyo to New York and 3.6 μSv h-1 from Los Angeles to Tokyo. These values agreed well with the predicted values presented by NCRP. (author)
Photon beam audits for radiation therapy clinics: A pilot mailed dosemeter study in Turkey
International Nuclear Information System (INIS)
A thermoluminescent dosemeter (TLD) mailed dose audit programme was performed at five radiotherapy clinics in Turkey. The intercomparison was organised by the Univ. of Wisconsin Radiation Calibration Laboratory (UWRCL), which was responsible for the technical aspects of the study including reference irradiations, distribution, collection and evaluation. The purpose of these audits was to perform an independent dosimetry check of the radiation beams using TLDs sent by mail. Acrylic holders, each with five TLD chips inside and instructions for their irradiation to specified absorbed dose to water of 2 Gy, were mailed to all participating clinics. TLD irradiations were performed with a 6 MV linear accelerator and 60Co photon beams. The deviations from the TL readings of UWRCL were calculated. Discrepancies inside the limits of ±5 % between the participant-stated dose, and the TLD-measured dose were considered acceptable. One out of 10 beams checked was outside this limit, with a difference of 5.8 %. (authors)
Ten years of personal neutron dosimetry with albedo dosemeters in The Netherlands.
Draaisma, F S; Verhagen, H W
Since 1987, the dosimetry service of the Netherlands Energy Research Foundation (ECN) has been certified by the Dutch government to perform personal dosimetry, using thermoluminescence dosemeters (TLDs). Performing neutron personal dosimetry requires a rather large investment in readers, TLDs and personnel to operate the service. About 800 persons are subjected to routine neutron monitoring in The Netherlands and their annual neutron doses are a relatively small fraction (less than 10%) of the annual Hp(10). In general, the measured neutron dose values are low (on average 93% of the users receive an annual neutron dose neutron) dose has tended to decrease since 1992, but incidentally high doses have been observed. Leaving these incidents out, the average collective annual neutron doses for the different users of neutron sources are about the same. PMID:12382755
Thermoluminescent dosemeters for determining the energy absorbed during X-ray radiography of the vertebral column
International Nuclear Information System (INIS)
The dose and absorbed energy during normal diagnostic X-ray of various sections of the vertebral column were determined with LiF-dosemeters in a phantom. The paper describes a method to be used to determine integral doses from the dose measurements. The energy absorbed for one X-ray picture of the vertebral column is between 5 and 30 mJ. Compared to other diagnostical X-rays the quantity of the energy absorbed during X-ray of the vertebral column is rather high and is only reached by X-rays in the pelvic region. The speculations on the rate of incidence of malignent neoplasms on the basis of diagnostical X-ray of the vertebral column reveal a value of 50 per 60 x 106 persons. This value is likely to overestimate the risk, seems, however, to be low in comparison to other risks of every day life (traffic accident, mountainering, etc). (orig./HP)
Kim, Jungho; Park, Hyeonseo; Kim, Yunho
Simulated workplace neutron fields have been developed at the Korea Research Institute of Standards and Science (KRISS). An (241)Am-Be neutron source and a cylindrical moderator composed of stainless steel and heavy water were installed in a 10-cm-thick concrete block with dimensions of 150 × 120 × 120 cm(3) The neutron energy spectrum at a distance of 66.5 cm was measured using a Bonner sphere spectrometer and was found to agree with the spectrum obtained from the Monte Carlo N-Particle Extended simulation to within 5 %. The neutron fluence-to-personal dose equivalent conversion coefficients were (20.8-43.6) pSv·cm(2) and were thus in good agreement with those of reactor fields. The results showed that the KRISS-simulated workplace neutron fields can be used for performance tests and the calibration service of neutron personal dosemeters. PMID:26541186
Nuclear HSP90 and HSP70 in COPD patients treated with formoterol or formoterol and corticosteroids
Holownia A; Mroz RM; Kielek A; Chyczewska E; Braszko JJ
Abstract Objective Heat shock proteins assist cellular protein folding and are required for the normal activity of steroid receptors. In this study we assessed nuclear HSP90 and HSP70 proteins and mRNA levels in cells isolated from induced sputum of chronic obstructive pulmonary disease patients treated for 4 weeks with formoterol (F) or formoterol+budesonide (F/ICS). Methods Nuclear heat shock protein levels were assessed by Western blot and specific mRNAs were quantified in cell lysates usi...
Hsp60 response in experimental and human temporal lobe epilepsy.
Marino Gammazza, Antonella; Colangeli, Roberto; Orban, Gergely; Pierucci, Massimo; Di Gennaro, Giancarlo; Lo Bello, Margherita; D'Aniello, Alfredo; Bucchieri, Fabio; Pomara, Cristoforo; Valentino, Mario; Muscat, Richard; Benigno, Arcangelo; Zummo, Giovanni; de Macario, Everly Conway; Cappello, Francesco; Di Giovanni, Giuseppe; Macario, Alberto J L
The mitochondrial chaperonin Hsp60 is a ubiquitous molecule with multiple roles, constitutively expressed and inducible by oxidative stress. In the brain, Hsp60 is widely distributed and has been implicated in neurological disorders, including epilepsy. A role for mitochondria and oxidative stress has been proposed in epileptogenesis of temporal lobe epilepsy (TLE). Here, we investigated the involvement of Hsp60 in TLE using animal and human samples. Hsp60 immunoreactivity in the hippocampus, measured by Western blotting and immunohistochemistry, was increased in a rat model of TLE. Hsp60 was also increased in the hippocampal dentate gyrus neurons somata and neuropil and hippocampus proper (CA3, CA1) of the epileptic rats. We also determined the circulating levels of Hsp60 in epileptic animals and TLE patients using ELISA. The epileptic rats showed circulating levels of Hsp60 higher than controls. Likewise, plasma post-seizure Hsp60 levels in patients were higher than before the seizure and those of controls. These results demonstrate that Hsp60 is increased in both animals and patients with TLE in affected tissues, and in plasma in response to epileptic seizures, and point to it as biomarker of hippocampal stress potentially useful for diagnosis and patient management.
Hsp60 response in experimental and human temporal lobe epilepsy
Gammazza, Antonella Marino; Colangeli, Roberto; Orban, Gergely; Pierucci, Massimo; Di Gennaro, Giancarlo; Bello, Margherita Lo; D'Aniello, Alfredo; Bucchieri, Fabio; Pomara, Cristoforo; Valentino, Mario; Muscat, Richard; Benigno, Arcangelo; Zummo, Giovanni; de Macario, Everly Conway; Cappello, Francesco; Di Giovanni, Giuseppe; Macario, Alberto J. L.
The mitochondrial chaperonin Hsp60 is a ubiquitous molecule with multiple roles, constitutively expressed and inducible by oxidative stress. In the brain, Hsp60 is widely distributed and has been implicated in neurological disorders, including epilepsy. A role for mitochondria and oxidative stress has been proposed in epileptogenesis of temporal lobe epilepsy (TLE). Here, we investigated the involvement of Hsp60 in TLE using animal and human samples. Hsp60 immunoreactivity in the hippocampus, measured by Western blotting and immunohistochemistry, was increased in a rat model of TLE. Hsp60 was also increased in the hippocampal dentate gyrus neurons somata and neuropil and hippocampus proper (CA3, CA1) of the epileptic rats. We also determined the circulating levels of Hsp60 in epileptic animals and TLE patients using ELISA. The epileptic rats showed circulating levels of Hsp60 higher than controls. Likewise, plasma post-seizure Hsp60 levels in patients were higher than before the seizure and those of controls. These results demonstrate that Hsp60 is increased in both animals and patients with TLE in affected tissues, and in plasma in response to epileptic seizures, and point to it as biomarker of hippocampal stress potentially useful for diagnosis and patient management. PMID:25801186
Overexpression of GmHsp90s, a heat shock protein 90 (Hsp90 gene family cloning from soybean, decrease damage of abiotic stresses in Arabidopsis thaliana.
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Jinyan Xu
Full Text Available Hsp90 is one of the most conserved and abundant molecular chaperones and is an essential component of the protective stress response; however, its roles in abiotic stress responses in soybean (Glycine max remain obscure. Here, 12 GmHsp90 genes from soybean were identified and found to be expressed and to function differentially under abiotic stresses. The 12 GmHsp90 genes were isolated and named GmHsp90A1-GmHsp90A6, GmHsp90B1, GmHsp90B2, GmHsp90C1.1, GmHsp90C1.2, GmHsp90C2.1 and GmHsp90C2.2 based on their characteristics and high homology to other Hsp90s according to a new nomenclature system. Quantitative real-time PCR expression data revealed that all the genes exhibited higher transcript levels in leaves and could be strongly induced under heat, osmotic and salt stress but not cold stress. Overexpression of five typical genes (GmHsp90A2, GmHsp90A4, GmHsp90B1, GmHsp90C1.1 and GmHsp90C2.1 in Arabidopsis thaliana provided useful evidences that GmHsp90 genes can decrease damage of abiotic stresses. In addition, an abnormal accumulation of proline was detected in some transgenic Arabidopsis plants suggested overexpressing GmHsp90s may affect the synthesis and response system of proline. Our work represents a systematic determination of soybean genes encoding Hsp90s, and provides useful evidence that GmHsp90 genes function differently in response to abiotic stresses and may affect the synthesis and response system of proline.
The β-ray energy and angular response of the EYE-D™ eye-lens dosemeter
International Nuclear Information System (INIS)
Following the recent ICRP recommendation to decrease the limit of occupational exposure to the eye lens from 150 mSv to 20 mSv/year, a dedicated individual eye-lens dosemeter, EYE-D™, was developed at the IFJ PAN. This dosemeter uses MCP-N (LiF:Mg,Cu,P) thermoluminescent detectors covered with a polyamide capsule and was so far optimized to achieve a flat photon energy and angular response for X-ray exposures typical in interventional radiology. To verify the applicability of this eye-lens dosemeter in external β-ray fields which arise, e.g. in nuclear medicine procedures, we measured and calculated its β-ray energy and angular response. Measurements, applying β-rays from Sr-90/Y-90 isotope, were performed at the Beta Secondary Standard type 2 (BSS 2) in CLOR. Calculations, using the PENELOPE Monte Carlo transport code which simulates coupled electron and photon transport in arbitrary materials, were performed for P-32, K-42 and Sr-90/Y-90 fields to simulate doses received by the eye lens within the human body. PENELOPE Monte Carlo transport code was also used to calculate doses received with EYE-D™ detectors. We found good agreement between the measured and calculated energy and angular responses which confirms the suitability of this dosemeter in assessing Hp(3) to estimate the eye lens. Obtained results and conclusions, however preliminary, conform with current ICRP recommendations when performing individual radiation protection dosimetry in external β-ray fields occurring in nuclear industry and nuclear medicine activities. -- Highlights: •The applicability of EYE-D™ eye-lens dosemeter in external β-ray fields have been investigated. •Measurements and calculations β-ray energy and angular response of EYE-D™ have been performed. •A comparison of calculations results with experimental data is presented. •Obtained results confirmed the suitability of this dosemeter in assessing Hp(3) to estimate the eye lens
C-terminal sequences of hsp70 and hsp90 as non-specific anchors for tetratricopeptide repeat (TPR) proteins.
Ramsey, Andrew J; Russell, Lance C; Chinkers, Michael
Steroid-hormone-receptor maturation is a multi-step process that involves several TPR (tetratricopeptide repeat) proteins that bind to the maturation complex via the C-termini of hsp70 (heat-shock protein 70) and hsp90 (heat-shock protein 90). We produced a random T7 peptide library to investigate the roles played by the C-termini of the two heat-shock proteins in the TPR-hsp interactions. Surprisingly, phages with the MEEVD sequence, found at the C-terminus of hsp90, were not recovered from our biopanning experiments. However, two groups of phages were isolated that bound relatively tightly to HsPP5 (Homo sapiens protein phosphatase 5) TPR. Multiple copies of phages with a C-terminal sequence of LFG were isolated. These phages bound specifically to the TPR domain of HsPP5, although mutation studies produced no evidence that they bound to the domain's hsp90-binding groove. However, the most abundant family obtained in the initial screen had an aspartate residue at the C-terminus. Two members of this family with a C-terminal sequence of VD appeared to bind with approximately the same affinity as the hsp90 C-12 control. A second generation pseudo-random phage library produced a large number of phages with an LD C-terminus. These sequences acted as hsp70 analogues and had relatively low affinities for hsp90-specific TPR domains. Unfortunately, we failed to identify residues near hsp90's C-terminus that impart binding specificity to individual hsp90-TPR interactions. The results suggest that the C-terminal sequences of hsp70 and hsp90 act primarily as non-specific anchors for TPR proteins.
Targeting membrane heat-shock protein 70 (Hsp70) on tumors by cmHsp70.1 antibody
Stangl, Stefan; Gehrmann, Mathias; Riegger, Julia; Kuhs, Kristin; Riederer, Isabelle; Sievert, Wolfgang; Hube, Kathrin; Mocikat, Ralph; Dressel, Ralf; Kremmer, Elisabeth; Pockley, Alan G.; Friedrich, Lars; Vigh, Laszlo; Skerra, Arne; Multhoff, Gabriele
Immunization of mice with a 14-mer peptide TKDNNLLGRFELSG, termed "TKD," comprising amino acids 450–461 (aa450–461) in the C terminus of inducible Hsp70, resulted in the generation of an IgG1 mouse mAb cmHsp70.1. The epitope recognized by cmHsp70.1 mAb, which has been confirmed to be located in the TKD sequence by SPOT analysis, is frequently detectable on the cell surface of human and mouse tumors, but not on isogenic cells and normal tissues, and membrane Hsp70 might thus serve as a tumor-specific target structure. As shown for human tumors, Hsp70 is associated with cholesterol-rich microdomains in the plasma membrane of mouse tumors. Herein, we show that the cmHsp70.1 mAb can selectively induce antibody-dependent cellular cytotoxicity (ADCC) of membrane Hsp70+ mouse tumor cells by unstimulated mouse spleen cells. Tumor killing could be further enhanced by activating the effector cells with TKD and IL-2. Three consecutive injections of the cmHsp70.1 mAb into mice bearing CT26 tumors significantly inhibited tumor growth and enhanced the overall survival. These effects were associated with infiltrations of NK cells, macrophages, and granulocytes. The Hsp70 specificity of the ADCC response was confirmed by preventing the antitumor response in tumor-bearing mice by coinjecting the cognate TKD peptide with the cmHsp70.1 mAb, and by blocking the binding of cmHsp70.1 mAb to CT26 tumor cells using either TKD peptide or the C-terminal substrate-binding domain of Hsp70. PMID:21187371
Determination of isodose curves in Radiotherapy using an Alanine/ESR dosemeter; Determinacion de curvas de isodosis en Radioterapia usando un dosimetro de Alanina/ESR
Energy Technology Data Exchange (ETDEWEB)
Chen, F.; Baffa, O.; Graeff, C.F.O. [Departamento de Fisica e Matematica. Universidade de Sao Paulo FFCLRP. 14040-901 Ribeirao Preto-SP (Brazil)
It was studied the possible use of an Alanine/ESR dosemeter in the isodose curves mapping in normal treatments of Radiotherapy. It was manufactured a lot of 150 dosemeters with base in a mixture of D-L Alanine dust (80 %) and paraffin (20 %). Each dosemeter has 4.7 mm diameter and 12 mm length. A group of 100 dosemeters of the lot were arranged inside 50 holes of the slice 25 of the phantom Rando Man. The phantom irradiation was realized in two opposed projections (AP and PA) in Co-60 equipment. A group of 15 dosemeters was take of the same lot for obtaining the calibration curve in a 1-20 Gy range. After irradiation the signal of each dosemeter was measured in an ESR spectrometer operating in the X-band ({approx} 9.5 GHz) and the wideness of Alanine ESR spectra central line was correlated with the radiation dose. The wideness dose calibration curve resulted linear with a correlation coefficient 0.9996. The isodose curves obtained show a profile enough similar at comparing with the theoretical curves. (Author)
Romero, Ana M; Grimbergen, Tom; McWhan, Andrew; Stadtmann, Hannes; Fantuzzi, Elena; Clairand, Isabelle; Neumaier, Stefan; Figel, Markus; Dombrowski, Harald
The European Radiation Dosimetry Group (EURADOS) has been organising dosimetry intercomparisons for many years in response to an identified requirement from individual monitoring services (IMS) for independent performance tests for dosimetry systems. The participation in intercomparisons gives IMS the opportunity to show compliance with their own quality management system, compare results with other participants and develop plans for improving their dosimetry systems. In response to growing demand, EURADOS has increased the number of intercomparisons for external radiation dosimetry. Most of these fit into the programme of self-financing intercomparisons for dosemeters routinely used by IMS. This programme is being coordinated by EURADOS working group 2 (WG2). Up to now, this programme has included four intercomparisons for whole-body dosemeters in photon fields, one for extremity dosemeters in photon and beta fields, and one for whole-body dosemeters in neutron fields. Other EURADOS working groups have organised additional intercomparisons including events in 2014 for eye-lens dosemeters and passive area dosemeters for environmental monitoring. In this paper, the organisation and achievements of these intercomparisons are compared in detail focusing on the similarities and differences in their execution. PMID:26759475
Conserved Distal Loop Residues in the Hsp104 and ClpB Middle Domain Contact Nucleotide-binding Domain 2 and Enable Hsp70-dependent Protein Disaggregation*
DeSantis, Morgan E.; Sweeny, Elizabeth A.; Snead, David; Leung, Eunice H.; Go, Michelle S.; Gupta, Kushol; Wendler, Petra; Shorter, James
The homologous hexameric AAA+ proteins, Hsp104 from yeast and ClpB from bacteria, collaborate with Hsp70 to dissolve disordered protein aggregates but employ distinct mechanisms of intersubunit collaboration. How Hsp104 and ClpB coordinate polypeptide handover with Hsp70 is not understood. Here, we define conserved distal loop residues between middle domain (MD) helix 1 and 2 that are unexpectedly critical for Hsp104 and ClpB collaboration with Hsp70. Surprisingly, the Hsp104 and ClpB MD dist...
Mesothelioma Cells Escape Heat Stress by Upregulating Hsp40/Hsp70 Expression via Mitogen-Activated Protein Kinases
Directory of Open Access Journals (Sweden)
Michael Roth
Full Text Available Therapy with hyperthermal chemotherapy in pleural diffuse malignant mesothelioma had limited benefits for patients. Here we investigated the effect of heat stress on heat shock proteins (HSP, which rescue tumour cells from apoptosis. In human mesothelioma and mesothelial cells heat stress (39–42°C induced the phosphorylation of two mitogen activated kinases (MAPK Erk1/2 and p38, and increased Hsp40, and Hsp70 expression. Mesothelioma cells expressed more Hsp40 and were less sensitive to heat stress compared to mesothelial cells. Inhibition of Erk1/2 MAPK by PD98059 or by Erk1 siRNA down-regulated heat stress-induced Hsp40 and Hsp70 expression and reduced mesothelioma cell survival. Inhibition of p38MAPK by SB203580 or siRNA reduced Hsp40, but not Hsp70, expression and also increased mesothelioma cell death. Thus hyperthermia combined with suppression of p38 MAPK or Hsp40 may represent a novel approach to improve mesothelioma therapy.
Targeting membrane heat-shock protein 70 (Hsp70) on tumors by cmHsp70.1 antibody
Stangl, Stefan; Gehrmann, Mathias; Riegger, Julia; Kuhs, Kristin; Riederer, Isabelle; Sievert, Wolfgang; Hube, Kathrin; Mocikat, Ralph; Dressel, Ralf; Kremmer, Elisabeth; Pockley, Alan G.; Friedrich, Lars; Vigh, Laszlo; Skerra, Arne; Multhoff, Gabriele
Immunization of mice with a 14-mer peptide TKDNNLLGRFELSG, termed "TKD," comprising amino acids 450–461 (aa450–461) in the C terminus of inducible Hsp70, resulted in the generation of an IgG1 mouse mAb cmHsp70.1. The epitope recognized by cmHsp70.1 mAb, which has been confirmed to be located in the TKD sequence by SPOT analysis, is frequently detectable on the cell surface of human and mouse tumors, but not on isogenic cells and normal tissues, and membrane Hsp70 might thus serve as a tumor-s...
Hsp90 phosphorylation, Wee1 and the cell cycle.
Mollapour, Mehdi; Tsutsumi, Shinji; Neckers, Len
Heat Shock Protein 90 (Hsp90) is an essential molecular chaperone in eukaryotic cells, and it maintains the functional conformation of a subset of proteins that are typically key components of multiple regulatory and signaling networks mediating cancer cell proliferation, survival, and metastasis. It is possible to selectively inhibit Hsp90 using natural products such as geldanamycin (GA) or radicicol (RD), which have served as prototypes for development of synthetic Hsp90 inhibitors. These compounds bind within the ADP/ATP-binding site of the Hsp90 N-terminal domain to inhibit its ATPase activity. As numerous N-terminal domain inhibitors are currently undergoing extensive clinical evaluation, it is important to understand the factors that may modulate in vivo susceptibility to these drugs. We recently reported that Wee1Swe1-mediated, cell cycle-dependent, tyrosine phosphorylation of Hsp90 affects GA binding and impacts cancer cell sensitivity to Hsp90 inhibition. This phosphorylation also affects Hsp90 ATPase activity and its ability to chaperone a selected group of clients, comprised primarily of protein kinases. Wee1 regulates the G2/M transition. Here we present additional data demonstrating that tyrosine phosphorylation of Hsp90 by Wee1Swe1 is important for Wee1Swe1 association with Hsp90 and for Wee1Swe1 stability. Yeast expressing non-phosphorylatable yHsp90-Y24F, like swe1∆ yeast, undergo premature nuclear division that is insensitive to G2/M checkpoint arrest. These findings demonstrate the importance of Hsp90 phosphorylation for proper cell cycle regulation. PMID:20519952
Comparison of neutron dose quantities and instrument and dosemeter readings at representative locations in an MOX fuel fabrication plant
Bartlett, D T; Tanner, R J; Haley, R M; Cooper, A J
The relationships between operational and protection quantities, and values of personal dosemeter and instrument readings have been determined for a recently designed MOX fuel fabrication plant. The relationships between the quantities, and the readings of personal dosemeters are sensitive to both the energy and direction distribution of neutron fluence. The energy distributions were calculated using the Monte Carlo code MCBEND. The direction distribution was addressed by calculating independently, spectral components for which the direction distribution could be reasonably assumed. At representative locations, and for assumed worker orientations, the radiation field is analysed as having, in general, three components--a direct, unidirectional component from the nearest identified discrete source, which is considered incident A-P, several unidirectional components from other such sources which are treated as a rotational component and a scattered isotropic component. The calculated spectra were folded with co...
New ICRU quantities for the environmental and individual monitoring. Standardization of individual dosemeters by using external beams of photon radiation
International Nuclear Information System (INIS)
The quantities introduced by ICRU for the radiological monitoring are commented, specially those implied in individual protection against external photons. A procedure is proposed in order to standardize the individual dosemeters by using the kerma in air references of CIEMAT-JEN. The reference radiation beams are described in connection with ISO standards. Provisional values are selected for the appropriate conversion and correction factors. (Author) 23 refs
Comparative Study on the Immunogenicity between Hsp70 DNA Vaccine and Hsp65 DNA Vaccine in Human Mycobacterium Tuberculosis
Institute of Scientific and Technical Information of China (English)
DAI; Wuxing; HUANG; Hailang; YUAN; Ye; HU; Jiajie; HUANGFU; Yongmu
The BALB/c mice were immunized with Hsp70 DNA and Hsp65 DNA vaccines in human Mycobacterium tuberculosis. Eight weeks after immunization, the eyeballs were removed, blood and spleen taken, and intraperitoneal macrophages were harvested. The lymphocytic stimulating index(SI) was used to measure the cellular proliferating ability and NO release to measure the phagocytic activity of the macrophages. With ELISA kit, the levels of interleukin-2 (IL-2) and interferon-γ(IFN-γ) in serum and the splenic lymphocytic cultured supernatant were detected. The results showed that after the mice were immunized with 100 μg/mouse of Hsp70 DNA vaccine intramuscularly, the splenic lymphocytic proliferating ability in the mice was significantly increased as compared with that in the control group, vector group and Hsp65 DNA vaccine group (P<0. 01); The contents of NO in the intraperitoneal macrophages of the mice were significantly lower than in the control group and Hsp65 DNA vaccine group (P<0. 01); The levels of serum IL-2 in the mice were significantly higher than in the control group, but there was no statistical difference between Hsp65 DNA group and vector group (P>0. 05); The contents of serum IFN-γ in the mice were significantly higher than in the control group, but significantly lower than in the Hsp65 DNA vaccine group (P<0. 05). It was indicated that immunization with Hsp70 DNA vaccine could obviously enhance the immune response, but its intensity seemed inferior to Hsp65 DNA vaccine. The anti-infection mechanisms and clinical use in the future of the vaccines of Hsp70 DNA and Hsp65 DNA are worth further studying.
A role for anti-HSP60 antibodies in arthritis
DEFF Research Database (Denmark)
Carlsen, Thomas Gelsing; Bennike, Tue; Christiansen, Gunna;
As a result of the high sequence similarity between HSP60 proteins, found in both prokaryotic and eukaryotic cells, it has been suggested, but never concluded, that anti-HSP60 antibodies could be of importance in the pathology of arthritis diseases explained by a concept named molecular mimicry...
Interactions between curcumin and Hsp90 and effects of curcumin on Hsp90 ATPase activity%姜黄素与Hsp90相互作用以及对Hsp90ATPase 活性的影响
Institute of Scientific and Technical Information of China (English)
范莹娟; 许建华
目的 研究姜黄素(curcumin)与Hsp90的结合作用,及其对Hsp90-ATPase 活性抑制作用.方法 采用荧光光谱实验,选取280 nm为激发波长,290~510 nm的波长范围内进行荧光光谱扫描,研究不同浓度curcumin与Hsp90的相互作用.采用孔雀绿磷钼酸铵-无机磷检测法,研究curcumin对Hsp90-ATPase活性抑制.结果 curcumin解离常数为(21.608±1.752) μmol·L-1,格尔德霉素(GA)为(17.372±1.200) μmol·L-1.当ATP为1 mmol·L-1时,GA作用于Hsp90的IC50值为0.38 μmol·L-1,curcumin的IC50值为3.75 μmol·L-1也有较强的Hsp90-ATPase抑制活性.结论 经过荧光光谱分析,可以确定curcumin与Hsp90的结合机制,且curcumin能抑制Hsp90-ATPase活性.
Measurement of staff doses in interventional procedures using LiF TL-detectors and a special diode dosemeter
Energy Technology Data Exchange (ETDEWEB)
Parviainen, T.; Toivonen, M.; Kosunen, A.; Karppinen, J. [Radiation and Nuclear Safety Authority, Helsinki (Finland); Ylitalo, A. [Satakunta Central Hospital, Division for Cardiology, Pori (Finland)
Personal doses vary considerably among the operational staff in cardiac examination procedures and interventions. Correspondingly, the fluoroscopy time may vary from a few minutes to more than 1 hour. Large personal doses in the range of 35 - 41 mSv were registered to some interventional radiologists and cardiologists in 2001 in Finland. Measurement of doses per intervention from hands, shoulders and ankles (parts of the body outside the lead apron) are therefore of interest, but small and highly sensitive dosemeters have not been commonly available for reliable and practical measurements. Thermoluminescent detectors of LiF:MgCu,P are sensitive enough, but residual luminescence from previous uses of detectors and the dose collected from natural background radiation between preparation for use and readout may be significant sources of uncertainty. The company Unfors Instrumens AB (Billdal, Sweden) has designed a light weight diode dosemeter with long cables between detectors and the electronic part for simultaneous measurement of doses from various parts of the body. The aim of this work is to report doses of the operating staff per a cardiac examination or intervention and study the capabilities of the diode dosemeter in staff dose measurements. (orig.)
Comparison of neutron dose quantities and instrument and dosemeter readings at representative locations in an MOX fuel fabrication plant
Bartlett, D. T.; Hager, L. G.; Tanner, R. J.; Haley, R. M.; Cooper, A. J.
The relationships between operational and protection quantities, and values of personal dosemeter and instrument readings have been determined for a recently designed MOX fuel fabrication plant. The relationships between the quantities, and the readings of personal dosemeters are sensitive to both the energy and direction distribution of neutron fluence. The energy distributions were calculated using the Monte Carlo code MCBEND. The direction distribution was addressed by calculating independently, spectral components for which the direction distribution could be reasonably assumed. At representative locations, and for assumed worker orientations, the radiation field is analysed as having, in general, three components—a direct, unidirectional component from the nearest identified discrete source, which is considered incident A-P, several unidirectional components from other such sources which are treated as a rotational component and a scattered isotropic component. The calculated spectra were folded with conversion coefficients for personal dose equivalent, Hp(10) slab (A-P, ROT and ISO), effective dose, E, (A-P, ROT and ISO), ambient dose equivalent, H*(10), personal dosemeter (AP, ROT and ISO) and survey instrument response characteristics.
The Progress of HSP22 Research%HSP22研究进展
Institute of Scientific and Technical Information of China (English)
陶希; 卢伟; 胡治平; 郑丽君; 宋涛
HSP22是小热休克蛋白超家族成员之一,主要在脑、心肌和骨骼肌广泛表达,而在子宫、前列腺、肺和肾脏等组织表达一般.当各种物理、化学等因素刺激时,可启动HSP22 mRNA快速表达;再通过HSP22 N末端区域和(或)C末端区域特定位点的突变或磷酸化反应,不同构象间相互转化及作用,在保持伴侣活性、激酶活性、触发炎性介质释放、抗凋亡与致凋亡和保护细胞骨架等方面起主要作用.其活性下降会导致遗传性末梢运动神经病、Alzheimer病、结蛋白相关心肌病、乳腺癌及白内障等相关疾病的发生发展.由于其在生命领域的特殊功能作用,目前生物医学界对其研究广泛.本文收集近期国内外文献,从分子和细胞水平综述了HSP22在基因表达、分子结构、生物学活性及与临床疾病关系的最新研究进展,以供学习交流.%HSP22 is a member of the superfamily of small heat-shock proteins, expressing predominantly in brain, heart and skeletal muscle, commonly in uterus , prostate , lung and kidney tissues. When activated by physical or chemistry factors , HSP22 mRNA express quickly in different tissues. Mutation in definite point or phosphorylation reaction in N terminal region and(or) C terminal region of HSP22, following reciprocal transformation and reaction in different conformation, which plays a critical role in the maintenance of chaperone activity, kinase activity, triggering the discharge of mediators of inflammation, anti-apoptosis or pro-apoptosis , protection of cytoskeleton, and so on. A decrease in the HSP22 activity may contribute to the development of heritage distal motor neuropathy, Alzheimer's disease, Desmin relevant cardiomyopathy, Breast cancer, Cataract, and so on. Because of its special functions and roles in life area, it was widely researched by persons in biomedicine territory now. In this review, we will collect literature of home and abroad and discuss recent
Anticancer Inhibitors of Hsp90 Function: Beyond the Usual Suspects.
Garg, Gaurav; Khandelwal, Anuj; Blagg, Brian S J
The 90-kDa heat-shock protein (Hsp90) is a molecular chaperone responsible for the stability and function of a wide variety of client proteins that are critical for cell growth and survival. Many of these client proteins are frequently mutated and/or overexpressed in cancer cells and are therefore being actively pursued as individual therapeutic targets. Consequently, Hsp90 inhibition offers a promising strategy for simultaneous degradation of several anticancer targets. Currently, most Hsp90 inhibitors under clinical evaluation act by blocking the binding of ATP to the Hsp90 N-terminal domain and thereby, induce the degradation of many Hsp90-dependent oncoproteins. Although, they have shown some promising initial results, clinical challenges such as induction of the heat-shock response, retinopathy, and gastrointestinal tract toxicity are emerging from human trials, which constantly raise concerns about the future development of these inhibitors. Novobiocin derivatives, which do not bind the chaperone's N-terminal ATPase pocket, have emerged over the past decade as an alternative strategy to inhibit Hsp90, but to date, no derivative has been investigated in the clinical setting. In recent years, a number of natural or synthetic compounds have been identified that modulate Hsp90 function via various mechanisms. These compounds not only offer new chemotypes for the development of future Hsp90 inhibitors but can also serve as chemical probes to unravel the biology of Hsp90. This chapter presents a synopsis of inhibitors that directly, allosterically, or even indirectly alters Hsp90 function, and highlights their proposed mechanisms of action. PMID:26916001
Interactions of p60, a mediator of progesterone receptor assembly, with heat shock proteins hsp90 and hsp70
DEFF Research Database (Denmark)
Chen, S; Prapapanich, V; Rimerman, R A;
mature PR complexes. In the present study we observe that a monoclonal antibody specific for p60 can, on the one hand, inhibit formation of mature PR complexes containing heat shock protein 90 (hsp90), p23, and immunophilins and, on the other, enhance recovery of early PR complexes containing hsp70...
Development of a extremity thermoluminescence dosemeter for photon dose equivalent assessment
International Nuclear Information System (INIS)
An extremely thermoluminescence dosimeter, to be used when the extremity may become the limiting organ, based on CaSO4:Dy pellet was developed to be worn as wristlet by technicians who work with unsealed sources or handle radioactive materials. This system permits photon dose equivalent assessment as well as the effective energy determination. Such dosemeter has to be worn in addition to a whole-body dosemeter. The system consists of two pieces of polyethylene with dimensions of 40 mm x 20 mm x 10 mm that can be superimposed and three discs of CaSO4:Dy plus Teflon (PTFE), as sensitive material, between different filters. The detectors are produced by the Dosimetric Materials Laboratory of IPEN and have diameter of 6.0 mm and a thickness of 0.8 mm. One detector is placed between plastic filters of 3.0 mm thickness that guarantees electronic equilibrium for 60Co gamma rays. Another detector is located between 1.0 mm thick lead filters plus 3.0 mm plastic filters. A third detector is sandwiched between filters of lead 0.8 mm thick with a central hole of 2.0 mm diameter and plastic filters of 3.0 mm thickness. The detectors are sealed in a plastic film 20 mg.cm-2 thick. All TL detectors are in contact with filters. The filter area is a little larger than the TL detector. The validation of the proposed dosimetric system was performed for 60Co gamma doses between 0.1 and 200 mGy. In this range the relationship dose-response is linear. The energy response of the dosimetric system was evaluated for an energy range between 30 and 662 keV. The maximum, relative to 60Co, energy dependence TL response is observed at 31.2 keV (factor 10.2). To obtain the dose equivalent and the effective energy from the correlation between the three TL readings was developed an algorithm. Taking into account the results obtained in simulated laboratory comparisons, better than ±5%, we conclude that the proposed dosimetric system agrees with the requirements for its application as extremity
Imaging of Hsp70-positive tumors with cmHsp70.1 antibody-conjugated gold nanoparticles
Directory of Open Access Journals (Sweden)
Gehrmann MK
Full Text Available Mathias K Gehrmann,1 Melanie A Kimm,2 Stefan Stangl,1 Thomas E Schmid,1 Peter B Noël,2 Ernst J Rummeny,2 Gabriele Multhoff11Department of Radiation Oncology, 2Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technische Universität München, Munich, GermanyAbstract: Real-time imaging of small tumors is still one of the challenges in cancer diagnosis, prognosis, and monitoring of clinical outcome. Targeting novel biomarkers that are selectively expressed on a large variety of different tumors but not normal cells has the potential to improve the imaging capacity of existing methods such as computed tomography. Herein, we present a novel technique using cmHsp70.1 monoclonal antibody-conjugated spherical gold nanoparticles for quantification of the targeted uptake of gold nanoparticles into membrane Hsp70-positive tumor cells. Upon binding, cmHsp70.1-conjugated gold nanoparticles but not nanoparticles coupled to an isotype-matched IgG1 antibody or empty nanoparticles are rapidly taken up by highly malignant Hsp70 membrane-positive mouse tumor cells. After 24 hours, the cmHsp70.1-conjugated gold nanoparticles are found to be enriched in the perinuclear region. Specificity for membrane Hsp70 was shown by using an Hsp70 knockout tumor cell system. Toxic side effects of the cmHsp70.1-conjugated nanoparticles are not observed at a concentration of 1–10 µg/mL. Experiments are ongoing to evaluate whether cmHsp70.1 antibody-conjugated gold nanoparticles are suitable for the detection of membrane-Hsp70-positive tumors in vivo.Keywords: heat shock protein 70, tumor biomarker, theranostics, multimodal CT, multispectral CT, k-edge
Structure, Function and Regulation of the Hsp90 Machinery
Directory of Open Access Journals (Sweden)
Jing Li
Full Text Available Heat shock protein 90 (Hsp90 is an ATP-dependent molecular chaperone which is essential in eukaryotes. It is required for the activation and stabilization of a wide variety of client proteins and many of them are involved in important cellular pathways. Since Hsp90 affects numerous physiological processes such as signal transduction, intracellular transport, and protein degradation, it became an interesting target for cancer therapy. Structurally, Hsp90 is a flexible dimeric protein composed of three different domains which adopt structurally distinct conformations. ATP binding triggers directionality in these conformational changes and leads to a more compact state. To achieve its function, Hsp90 works together with a large group of cofactors, termed co-chaperones. Co-chaperones form defined binary or ternary complexes with Hsp90, which facilitate the maturation of client proteins. In addition, posttranslational modifications of Hsp90, such as phosphorylation and acetylation, provide another level of regulation. They influence the conformational cycle, co-chaperone interaction, and inter-domain communications. In this review, we discuss the recent progress made in understanding the Hsp90 machinery.
Structure and expression of a rice hsp70 gene
Institute of Scientific and Technical Information of China (English)
王群; 方荣祥
A genomic hsp70 gene was isolated from a rice IR36 genomic library and 4 794 bp of the gene have been sequenoed. The 5' flanking region of the gene contained a putative TATA box and a typical heat shock element sequence 5'-CTcgGAAccTTCgAG-3'. The amino acid sequence of the rice HSP70 deduced from the coding region shared 84%-92% homologies with those of HSP70s from other plant species. An intron 1939bp long was identified in the coding region at the codon specifying amino acid 72 (Asp), the similar position introns occurring in other intron-containing hsp70 genes. In addition, another intron of 57 bp was found in the 3'-untranslated region in the rice hsp70 gene. Southern blot hybridization showed that rice hsp70 gene family contained at least three members. Analysis of the RNA leveis with the gene-specific and non-specific probes revealed that the rice hsp70 gene expressed at normal temperature and the expression was enhanced by heat shock treatment.
Hsp90 selectively modulates phenotype in vertebrate development.
Directory of Open Access Journals (Sweden)
Patricia L Yeyati
Full Text Available Compromised heat shock protein 90 (Hsp90 function reveals cryptic phenotypes in flies and plants. These observations were interpreted to suggest that this molecular stress-response chaperone has a capacity to buffer underlying genetic variation. Conversely, the protective role of Hsp90 could account for the variable penetrance or severity of some heritable developmental malformations in vertebrates. Using zebrafish as a model, we defined Hsp90 inhibitor levels that did not induce a heat shock response or perturb phenotype in wild-type strains. Under these conditions the severity of the recessive eye phenotype in sunrise, caused by a pax6b mutation, was increased, while in dreumes, caused by a sufu mutation, it was decreased. In another strain, a previously unobserved spectrum of severe structural eye malformations, reminiscent of anophthalmia, microphthalmia, and nanophthalmia complex in humans, was uncovered by this limited inhibition of Hsp90 function. Inbreeding of offspring from selected unaffected carrier parents led to significantly elevated malformation frequencies and revealed the oligogenic nature of this phenotype. Unlike in Drosophila, Hsp90 inhibition can decrease developmental stability in zebrafish, as indicated by increased asymmetric presentation of anophthalmia, microphthalmia, and nanophthalmia and sunrise phenotypes. Analysis of the sunrise pax6b mutation suggests a molecular mechanism for the buffering of mutations by Hsp90. The zebrafish studies imply that mild perturbation of Hsp90 function at critical developmental stages may underpin the variable penetrance and expressivity of many developmental anomalies where the interaction between genotype and environment plays a major role.
Role of HSP100 proteins in plant stress tolerance. Final technical report
Energy Technology Data Exchange (ETDEWEB)
Vierling, E.
This research focused on the following areas: characterization of HSP100 genes and their expression during stress and development; requirement of HSP101 for thermotolerance; thermotolerance of plants over-expressing HSP100; and identifying interacting proteins that functionally interact with HSP104.
Performance of CVD diamond as an optically and thermally stimulated luminescence dosemeter
International Nuclear Information System (INIS)
Diamond is a material with extreme physical properties. Its radiation hardness, chemical inertness and tissue equivalence qualify it as an ideal material for radiation dosimetry. In the present work, the optically stimulated luminescence (OSL) and thermoluminescence (TL) characteristics of a 10 μm thick CVD diamond (polycrystalline diamond films prepared by chemical vapor deposition) film were studied in order to test its performance as a beta radiation dosemeter. The TL response is composed of four main TL glow peaks; two of these are in the range of 150-200 deg. C and two additional peaks in the 250-400 deg. C temperature range. The integrated TL as a function of radiation dose is linear up to 100 Gy and increases with increasing dose exposure. The dose dependence of the integrated OSL exhibits a similar behavior. The observed OSL/TL behavior for the CVD diamond film clearly demonstrate its capability for applications in radiation dosimetry with special relevance in medical dosimetry owing to the diamond's intrinsic material properties. (authors)
Thermoluminescent and optical processes in alkaline halogenides dosemeters contaminated with Europium
International Nuclear Information System (INIS)
Recent research results are presented about the properties of the optical processes of photo transferred thermoluminescence (TLFT), optical whitening (BO), thermoluminescence induced by light (TLL) and its effect in the thermoluminescent curve (Tl) produced by ionizing and non-ionizing radiation. The systematic analysis of all these processes, acquires a singular importance due that actually the alkaline halogenide crystals are object of intense investigations which analyse their potential applications as detectors and radiation dosemeters through stimulated optical luminescence techniques or thermoluminescence. The obtained data show that the Tl curve of material with this nature can be enormously affected by exposure of phosphorus to the environmental light or UV. This is in part due to liberation processes of charge bearers are shouted and makes a subsequent trapping in less temperature traps; at the same time that induce changes in the intensity of determined Tl bands. Additionally, also it is observed that mentioned phenomena are related as with wavelength of incident light as of the illumination time. Finally, the obtained information allows to conclude that although the illumination effect is extremely complex, it is associated and can be explained mainly with phenomena that implicate the electrons excitation trapped in form of F centers and trapping mechanisms or radioactive and non-radioactive recombination. (Author)
The influence of time-temperature on the behaviour of TLD-100 as personal dosemeters
International Nuclear Information System (INIS)
Since 1965, the survey of individual exposure for the people working in the medical field is carried out within the Institute of Hygiene and Public Health, by a central service belonging to the Romanian Ministry of Health. During this period 6500 persons per month were monitored, using film-badges. The relative low sensitivity of film dosemeters lead to a decrease of confidence in this old system. Furthermore, the film badges do not have appropriate filters for measuring the personal equivalent doses Hp(10) and Hp(0.07), as are the new recommendations of ICRP and IAEA. These facts made clear there is a necessity of changing this type of monitoring system with another one, having a higher sensitivity and allowing the measurement of personal equivalent doses Hp(10) and Hp(0.07). The decision was to switch to a TL dosimetry system, namely the Harshaw 6600 System. The performances of this new system have to be checked by the TL Dosimetry Group, at the Institute of Hygiene and Public Health, before being officially accepted as the new individual dosimetry system. The paper presents the results of some of the test performed on the TLD-100 chips, concerning the influence of the heating rate and pre-heat temperature and duration (the time-temperature profiles) and the fading of the detectors. (author)
Evaluation of the directional dose equivalent H,(0.07) for ring dosemeters
International Nuclear Information System (INIS)
The personnel dosimetry laboratory (LDP) of the Metrology department received an user's of radiation beta application that incidentally had irradiated 14 couples of ring dosemeters for extremities of the type TLD-100 given by the LDP. This sample of 14 couples of rings tentatively it was irradiated in the months of July-August of the year 2004, and he requested in an expedite way the evaluation of the received dose equivalent. The LSCD builds two calibration curves in terms of the directional dose equivalent H'(0.07) using two sources patterns of 90 Sr-90 Y for beta radiation: one of 74 MBq and another of 1850 MBq with traceability to the PTB. The first curve in the interval of 0 to 5 mSv, the second in the range of 5 to 50 mSv, taking into account effects by positioned of the rings in the phantom. Both calibration curves were validated by adjustment lack, symmetry of residuals and normality of the same ones. It is evaluated and analyzing the H'(0.007) for these 14 couples of rings using the Tukey test of media of a single road. It was found that the H, its could be classified in 4 groups, and that the probability that its has irradiated in a random way it was smaller to the level at α = 0.05. (Author)
Active personal dosemeters in interventional radiology: tests in laboratory conditions and in hospitals.
Clairand, I; Bordy, J-M; Daures, J; Debroas, J; Denozière, M; Donadille, L; Ginjaume, M; Itié, C; Koukorava, C; Krim, S; Lebacq, A-L; Martin, P; Struelens, L; Sans-Mercé, M; Tosic, M; Vanhavere, F
The work package 3 of the ORAMED project, Collaborative Project (2008-11) supported by the European Commission within its seventh Framework Programme, is focused on the optimisation of the use of active personal dosemeters (APDs) in interventional radiology and cardiology (IR/IC). Indeed, a lack of appropriate APD devices is identified for these specific fields. Few devices can detect low-energy X rays (20-100 keV), and none of them are specifically designed for working in pulsed radiation fields. The work presented in this paper consists in studying the behaviour of some selected APDs deemed suitable for application in IR/IC. For this purpose, measurements under laboratory conditions, both with continuous and pulsed X-ray beams, and tests in real conditions on site in different European hospitals were performed. This study highlights the limitations of APDs for this application and the need of improving the APD technology so as to fulfil all needs in the IR/IC field.
The effect of radiation on bioluminescent bacteria: possible use of luminescent bacteria as a biological dosemeter
International Nuclear Information System (INIS)
The purpose of the study was to investigate the response of the bioluminescent Photobacterium phosphoreum to radiation, and the possible use of the bacteria as a biological radiation dosemeter, i.e. a water-equivalent biological system that will compare beams not merely on the basis of absorbed dose, but also have intrinsic RBE values for different radiation beams. Samples were irradiated by a 12 MeV electron beam at a dose rate of 3.0 Gy min-1, by 60Co gamma rays at 2.85 Gy min-1, and by 100 kVsub(p) x-rays at a dose rate of 2.13 Gy min-1. To study dose-rate dependence, the survival fraction was obtained for a 12 MeV electron beam at 0.50 and 12 Gy min-1 for 20.0 Gy. The survival fraction proved to be independent of dose rate in this range. The results presented in this work indicate that by using bioluminescent bacteria, RBE measurements can be markedly simplified and the results interpreted unequivocally. (U.K.)
Inducible HSP70 Protects Radiation-Induced Salivary Gland Damage
Energy Technology Data Exchange (ETDEWEB)
Lee, Hae-June; Lee, Yoon-Jin; Kwon, Hee-Choong; Lee, Su-Jae; Bae, Sang-Woo; Lee, Yun-Sil [Korea Institute of Radiological Medical Sciences, Seoul (Korea, Republic of); Kim, Sung-Ho [Chonnam National University, Gwangju (Korea, Republic of)
Irradiation (IR) delivered to the head and neck is a common treatment for malignancies. Salivary glands in the irradiation field are severely damaged, and consequently this resulted in marked salivary hypofunction. While the exact mechanism of salivary gland damage remains enigmatic, fluid secreting acinar cells are lost, and saliva output is dramatically reduced. Previously we have reported that inducible heat shock protein 70 (HSP70i) induced radioresistance in vitro. Moreover, HSP70i localized to salivary glands by gene transfer has great potential for the treatment of salivary gland. Herein, we investigated whether HSP70 can use as radio protective molecules for radiation-induced salivary gland damage in vivo.
HSP20 phosphorylation and airway smooth muscle relaxation
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Mariam Ba
Full Text Available Mariam Ba1, Cherie A Singer1, Manoj Tyagi2, Colleen Brophy3, Josh E Baker4, Christine Cremo4, Andrew Halayko5, William T Gerthoffer21Department of Pharmacology, University of Nevada School of Medicine, Reno, NV, USA; 2Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL, USA; 3Harrington Department of Biochemistry, Arizona State University, Tempe, AZ, USA; 4Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, USA; 5Departments of Physiology and Internal Medicine, University of Manitoba, Winnipeg, MB, CanadaAbstract: HSP20 (HSPB6 is a small heat shock protein expressed in smooth muscles that is hypothesized to inhibit contraction when phosphorylated by cAMP-dependent protein kinase. To investigate this hypothesis in airway smooth muscle (ASM we showed that HSP20 was constitutively expressed as well as being inducible in cultured hASM cells by treatment with 1 µM isoproterenol or 10 µM salmeterol. In contrast, a mixture of proinflammatory mediators (interleukin-1β, tumor necrosis factor α, and interferon γ inhibited expression of HSP20 by about 50% in 48 hours. To determine whether phosphorylation of HSP20 is sufficient to induce relaxation, canine tracheal smooth muscle was treated with a cell permeant phosphopeptide that mimics the phosphorylation of HSP20. The HSP20 phosphopeptide antagonized carbacholinduced contraction by 60% with no change in myosin light chain phosphorylation. Recombinant full length HSP20 inhibited skeletal actin binding to smooth muscle myosin subfragment 1 (S1, and recombinant cell permeant TAT-HSP20 S16D mutant reduced F-actin filaments in cultured hASM cells. Carbachol stimulation of canine tracheal smooth muscle tissue caused redistribution of HSP20 from large macromolecular complexes (200–500 kDa to smaller complexes (<60 kDa. The results are consistent with HSP20 expression and macromolecular structure being dynamically regulated in airway
Federal Laboratory Consortium — Description/History: Chemistry and biology laboratories The Bio Engineering Laboratory (BeL) is theonly full spectrum biotechnology capability within the Department...
Effect of the energy dependence of response of neutron personal dosemeters routinely used in the UK on the accuracy of dose estimation
Tanner, R J; Thomas, D J
A large set of neutron energy distributions have been classified by workplace to provide a guide to the neutron fields to which workers in particular industries are likely to be exposed. These have been combined (folded) with the results of a major programme of neutron personal dosemeter response function measurements, to provide results for the systematic errors that those dosemeters would give in workplaces. Data for neutron doses recorded for UK classified workers have been taken from the CIDI tables, and related to the results from the folding process. It has hence been possible to draw conclusions about the probable systematic errors that result from the use of the currently available neutron personal dosemeters, which have inherent problems associated with their energy dependence of response.
Optical fibre dosemeter systems for clinical applications based on radioluminescence and optically stimulated luminescence from Al2O3:C
DEFF Research Database (Denmark)
Marckmann, C.J.; Andersen, C.E.; Aznar, M.C.;
Optical fibre dosemeter systems based on radioluminescence and optically stimulated luminescence (OSL) from carbon-doped aluminium oxide (Al2O3:C) crystals were developed for in vivo real-time dose rate and absorbed dose measurements in radiotherapy and mammography. A technique was also developed...... dosemeter system showed a repeatability within 0.15% at a dose level of 60 mGy when integrated over 100 s. The temperature dependence in the range 0-45 degrees C showed a reproducibility within 1.3% when the OSL signal was integrated over 100 s....... for making ultra-small dosemeter probes that can easily be placed inside patients in radiation treatment. These probes have shown excellent properties in both head and neck intensity-modulated radiation therapy treatment and in mammography. The dose-response of the OSL signal for the new optical fibre...
Phage displaying epitope of Candida albicans HSP90 and serodiagnosis
Institute of Scientific and Technical Information of China (English)
杨琼; 王丽; 卢大宁; 邢沈阳; 尹东; 朱筱娟
@@ Recently, the frequent use of immunosuppressants and chemotherapeutic drugs for cancers has caused an increase in the frequency of life-threatening systemic candidiasis.1 Studies by Matthews et al2 indicated HSP90 fragments are major targets for the immune system in infection due to C. albicans, and anti-epitope LKVIRK of HSP90 antibody is a serological marker for diagnosis of invasive candidiasis. Cloning and sequencing HSP90 antigen revealed that the linear epitope LKVIRK, localized near the C-terminus of the 47 kDa protein which circulates in the sera of patients with invasive candidiasis, as a heat-stable breakdown product of large more heat-labile antigen HSP90.2 In this study, epitope LKVIRK was displayed on the surface of phage fd to develop a new serological test for systemic candidiasis.
Pathways of allosteric regulation in Hsp70 chaperones.
Kityk, Roman; Vogel, Markus; Schlecht, Rainer; Bukau, Bernd; Mayer, Matthias P
Central to the protein folding activity of Hsp70 chaperones is their ability to interact with protein substrates in an ATP-controlled manner, which relies on allosteric regulation between their nucleotide-binding (NBD) and substrate-binding domains (SBD). Here we dissect this mechanism by analysing mutant variants of the Escherichia coli Hsp70 DnaK blocked at distinct steps of allosteric communication. We show that the SBD inhibits ATPase activity by interacting with the NBD through a highly conserved hydrogen bond network, and define the signal transduction pathway that allows bound substrates to trigger ATP hydrolysis. We identify variants deficient in only one direction of allosteric control and demonstrate that ATP-induced substrate release is more important for chaperone activity than substrate-stimulated ATP hydrolysis. These findings provide evidence of an unexpected dichotomic allostery mechanism in Hsp70 chaperones and provide the basis for a comprehensive mechanical model of allostery in Hsp70s. PMID:26383706
The interplay between inhibition of JAK2 and HSP90
Fridman, Jordan S.; Sarlis, Nicholas J
A recent article by Weigert et al. published in The Journal of Experimental Medicine described the in vitro generation of synthetic mutations in Janus kinase 2 (JAK 2) that decreased the potency of JAK2 (or JAK1/JAK2) inhibitors in artificial systems. The authors found that heat shock protein 90 (HSP90) inhibitors circumvented the potency shift and suggested that HSP90 inhibition may abrogate JAK inhibitor resistance in these experimental systems. However, the clinical relevance of these labo...
Regulatory Circuits of the AAA+ Disaggregase Hsp104
Franzmann, Titus M.; Czekalla, Anna; Walter, Stefan G.
Yeast Hsp104 is an AAA+ chaperone that rescues proteins from the aggregated state. Six protomers associate to form the functional hexamer. Each protomer contains two AAA+ modules, NBD1 and NBD2. Hsp104 converts energy provided by ATP into mechanical force used to thread polypeptides through its axial channel, thereby disrupting protein aggregates. But how the action of its 12 AAA+ domains is co-ordinated to catalyze disaggregation remained unexplained. Here, we identify a sophisticated allost...
Pathways of allosteric regulation in Hsp70 chaperones
Kityk, Roman; Vogel, Markus; Schlecht, Rainer; Bukau, Bernd; Mayer, Matthias P
Central to the protein folding activity of Hsp70 chaperones is their ability to interact with protein substrates in an ATP-controlled manner, which relies on allosteric regulation between their nucleotide-binding (NBD) and substrate-binding domains (SBD). Here we dissect this mechanism by analysing mutant variants of the Escherichia coli Hsp70 DnaK blocked at distinct steps of allosteric communication. We show that the SBD inhibits ATPase activity by interacting with the NBD through a highly ...
Perbedaan Kadar HSP90 pada Preeklamsi Berat dengan Kehamilan Normal
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Full Text Available Severe pre-eclampsia is the second highest cause of maternal mortality. Free radicals that stimulate heat shock protein 90 (HSP 90 are believed to determine severe pre-eclampsia. HSP90 is an important protein that helps the establishment and maintenance of other proteins. It also increases the life time of cells after various pathological conditions (chaperone function. The chaperone function is the adaptation key factor to endogenous stress in tissues. By recognizing HSP90 level in early detection of severe pre-eclampsia, prevention and management can be started early. This study aimed to prove that the HSP90 level in pregnancy with severe pre-eclampsia is higher than normal pregnancy. This was a quantitative study using cross sectional approach by testing the HSP90 level. The study was conducted during the period of September to November 2013, at the Obstetrics and Gynecological Unit, Moewardi Hospital Surakarta and Prodia Laboratory Jakarta. The number of subjects was 30 patients, consisting of 15 normal pregnant mothers and 15 pregnant mothers with pre-eclampsia . The calculation of serum HSP90 level was conducted using enzyme-linked immunosorbent assay (ELISA. Data were analyzed using t-test using SPSS for Windows version 17 for Windows. The mean of HSP90 in the severe pre-eclampsia group was 131.91±26.66 while the mean in the normal pregnancy group was 80.28±13.39 with p=0.00 (p<0.05. Level of HSP90 serum in severe pre-eclampsia is higher than in normal pregnancy, due to the occurrence of oxidative stress in severe pre-eclampsia
Hsp100/ClpB Chaperone Function and Mechanism
Energy Technology Data Exchange (ETDEWEB)
Vierling, Elizabeth [University of Massachusetts
The supported research investigated the mechanism of action of a unique class of molecular chaperones in higher plants, the Hsp100/ClpB proteins, with the ultimate goal of defining how these chaperones influence plant growth, development, stress tolerance and productivity. Molecular chaperones are essential effectors of cellular "protein quality control", which comprises processes that ensure the proper folding, localization, activation and turnover of proteins. Hsp100/ClpB proteins are required for temperature acclimation in plants, optimal seed yield, and proper chloroplast development. The model plant Arabidopsis thaliana and genetic and molecular approaches were used to investigate two of the three members of the Hsp100/ClpB proteins in plants, cytosolic AtHsp101 and chloroplast-localized AtClpB-p. Investigating the chaperone activity of the Hsp100/ClpB proteins addresses DOE goals in that this activity impacts how "plants generate and assemble components" as well as "allowing for their self repair". Additionally, Hsp100/ClpB protein function in plants is directly required for optimal "utilization of biological energy" and is involved in "mechanisms that control the architecture of energy transduction systems".
Hsp60 and human aging: Les liaisons dangereuses.
Cappello, Francesco; Conway de Macario, Everly; Marino Gammazza, Antonella; Bonaventura, Giuseppe; Carini, Francesco; Czarnecka, Anna M; Farina, Felicia; Zummo, Giovanni; Macario, Alberto J L
Stressors can cause abnormal intracellular accumulation of Hsp60 and its localization in extramitochondrial sites, secretion, and circulation, with immune system activation. Dysfunction of chaperones associated with their quantitative and qualitative decline with aging (chaperonopathies of aging) characterizes senescence and is a potential causal factor in the physiological deterioration that occurs with it. The role of Hsp60 in aging is not easy to elucidate, because aging is accompanied by pathologies (e.g., cardiovascular and neurodegenerative disorders, osteoporosis, diabetes, cancer, etc.) in which Hsp60 has been implicated but, although those disorders are more frequent in the elderly, they are not unique to them. Therefore, it is difficult to determine what is due to aging and what to an associated disease that can occur regardless of age. Does Hsp60 contribute to the pathogenesis? How and when does Hsp60 interact with the immune system and, thus, contributes to the initiation-progression of the generalized chronic inflammation characteristic of aging? These and related issues are discussed here in the light of reports showing the participation of Hsp60 in aging-associated disorders.
Hsp10: anatomic distribution, functions, and involvement in human disease.
David, Sabrina; Bucchieri, Fabio; Corrao, Simona; Czarnecka, Anna M; Campanella, Claudia; Farina, Felicia; Peri, Giovanni; Tomasello, Giovanni; Sciumè, Carmelo; Modica, Giuseppe; La Rocca, Giampiero; Anzalone, Rita; Giuffrè, Mario; Conway De Macario, Everly; Macario, Alberto J L; Cappello, Francesco; Zummo, Giovanni
There is growing evidence that molecular chaperones/heat shock proteins are involved in the pathogenesis of a number of human diseases, known as chaperonopathies. A better molecular understanding of the pathogenetic mechanisms is essential for addressing new strategies in diagnostics, therapeutics and clinical management of chaperonopathies, including those in which Hsp10 is involved. This chaperonin has been studied for a long time as a member of the mitochondrial protein-folding machine. However, although in normal cells Hsp10 is mainly localized in the mitochondrial matrix, it has also been found during and after stress in other subcellular compartments, such as cytosol, vesicles and secretory granules, alone or in combination with other proteins. In these extramitochondrial locales, Hsp10 plays an active role in cell signalling. For example, cancer cells often show altered levels of Hsp10, compared to normal cells. Hsp10 may also be found in the extracellular space and in the bloodstream, with a possible immunomodulatory activity. This minireview focuses on some studies to date on the involvement of Hsp10 in human disease pathogenesis.
Hsp60 is actively secreted by human tumor cells.
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Anna M Merendino
Full Text Available BACKGROUND: Hsp60, a Group I mitochondrial chaperonin, is classically considered an intracellular chaperone with residence in the mitochondria; nonetheless, in the last few years it has been found extracellularly as well as in the cell membrane. Important questions remain pertaining to extracellular Hsp60 such as how generalized is its occurrence outside cells, what are its extracellular functions and the translocation mechanisms that transport the chaperone outside of the cell. These questions are particularly relevant for cancer biology since it is believed that extracellular chaperones, like Hsp70, may play an active role in tumor growth and dissemination. METHODOLOGY/PRINCIPAL FINDINGS: Since cancer cells may undergo necrosis and apoptosis, it could be possible that extracellular Hsps are chiefly the result of cell destruction but not the product of an active, physiological process. In this work, we studied three tumor cells lines and found that they all release Hsp60 into the culture media by an active mechanism independently of cell death. Biochemical analyses of one of the cell lines revealed that Hsp60 secretion was significantly reduced, by inhibitors of exosomes and lipid rafts. CONCLUSIONS/SIGNIFICANCE: Our data suggest that Hsp60 release is the result of an active secretion mechanism and, since extracellular release of the chaperone was demonstrated in all tumor cell lines investigated, our observations most likely reflect a general physiological phenomenon, occurring in many tumors.
Heat Shock Protein 90 (Hsp90 Expression and Breast Cancer
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Christos A. Papadimitriou
Full Text Available Hsp90 is an abundant protein in mammalian cells. It forms several discrete complexes, each containing distinct groups of co-chaperones that assist protein folding and refolding during stress, protein transport and degradation. It interacts with a variety of proteins that play key roles in breast neoplasia including estrogen receptors, tumor suppressor p53 protein, angiogenesis transcription factor HIF-1alpha, antiapoptotic kinase Akt, Raf-1 MAP kinase and a variety of receptor tyrosine kinases of the erbB family. Elevated Hsp90 expression has been documented in breast ductal carcinomas contributing to the proliferative activity of breast cancer cells; whilst a significantly decreased Hsp90 expression has been shown in infiltrative lobular carcinomas and lobular neoplasia. Hsp90 overexpression has been proposed as a component of a mechanism through which breast cancer cells become resistant to various stress stimuli. Therefore, pharmacological inhibition of HSPs can provide therapeutic opportunities in the field of cancer treatment. 17-allylamino,17-demethoxygeldanamycin is the first Hsp90 inhibitor that has clinically been investigated in phase II trial, yielding promising results in patients with HER2-overexpressing metastatic breast cancer, whilst other Hsp90 inhibitors (retaspimycin HCL, NVP-AUY922, NVP-BEP800, CNF2024/BIIB021, SNX-5422, STA-9090, etc. are currently under evaluation.
Application of Bioinformatics in the Study of HSP70 Recombinant Vaccine of Echinococcus Granulosus%生物信息学技术在细粒棘球蚴热休克蛋白70重组疫苗研究中的应用
Institute of Scientific and Technical Information of China (English)
丁淑琴; 刘宏鹏; 张爱君; 张彩芳; 赵巍
目的 通过基因序列分析,寻找细粒棘球蚴(Echinococcus granulosus,Eg)热休克蛋白基因(Heat shock pm-tein7,HSP70),为包虫病防治筛选新的候选疫苗抗原.方法 ①登录 GenBank 公共数据库,检索 EgHSP70目的基因序列.②对克隆基因进行测序,结果输入DNAStax、BioSun分析软件和互联网 SWISS-MODEI 数据库,对重组 EgHSP70 的特性、抗原表位及构象进行预测分析.结果 ①获得了具有完整开放阅读框的 EgHSP70核苷酸序列.②DNAStar分析软件推算氨基酸序列结果显示,EgHSP70由133个理论氨基酸组成,分子量约为14.53kDa.DNAStar、BioSun分析软件确定了重组 EgHSP70 可能的抗原表位.与其他动物热休克蛋白70氨基酸的同源性分析结果显示EgHSP70具有高度的保守性.结论 生物信息学技术在 EgHSP70 重组疫苗研究中有一定的理论和应用价值.
Determination of kinetic parameters in Tl dosemeters of LiF: Mg, Cu, P + PTFE developed in the ININ
International Nuclear Information System (INIS)
The objective of this work, is the one of determining the kinetic parameters of the dosemeter of LiF: Mg, Cu, P + Ptfe; starting from the curves Tl obtained at being irradiated with alpha radiation (α), beta (β) and gamma (γ). As like to compare its sensitivity with each radiation type, considering the sensitivity of the TLD-100 as the unit. In the Chapter 1, the fundamental structure of the matter is described, making emphasis in the different radiation types, and their interaction with this. In the Chapter 2, the units are described but used in the dosimetry of the radiation. In the Chapter 3, the basic concepts of the phenomenon of Tl are described and those are explained characteristic of the deconvolution method to determine the kinetics of the one phenomenon. In the Chapter 4, the methodology is detailed that was used in the elaboration of this thesis work, describing the material Tl that were considered like reference, as well as the sources of ionizing radiation, with those that the dosemeters were irradiated and the equipment in the one that the curves Tl was obtained. Reference is made to the software used to carry out the deconvolution of the curves Tl that were obtained in the one experimental development. In the Chapter 5, the obtained results of this study are presented, showing the tables of homogenization of dosemeters and the reading of the same one; they are observed the curves Tl obtained to different radiation doses (alpha, beta and gamma), the intensity Tl in function of the dose. Also they are tabulated, the obtained results in the kinetic parameters of the three different study materials (TLD-100H, USA; TLD-100, USA and LiF: Mg, Cu, P + Ptfe developed in the l.N.l.N). They are analyzed shortly for each material Tl their sensitivity to the ionizing radiation as well as their kinetic parameters. The obtained results showed that the Tl dosemeters of LiF: Mg,Cu,P + Ptfe, they presented a bigger sensitivity that the TLD-100 when being
Fiber-optic-coupled dosemeter for remote optical sensing of radiation
International Nuclear Information System (INIS)
Remote sensing technologies for the detection and measurement of ionizing radiation exposure are of current interest for applications such as patient dose verification during radiotherapy and the monitoring of environmental contaminants. Fiberoptic-based sensing is attractive due to the advantages of small size, low cost, long life and freedom from electromagnetic interference. Several fiberoptic-based radiation sensing systems have been described that utilize radiation induced changes in the optical characteristics of the fiber such as reduced transmission as a result of darkening of the glass, optical phase shifts due to heating, or changes in the birefringence of a polarization-maintaining fiber. The measurement of radiation induced darkening is limited in both sensitivity and dynamic range and requires long fiber lengths. Phase shift measurements require the use of single-mode lasers, phase sensitive interferometric detection, long fiber lengths and complex signal processing techniques. Alternatively, thermoluminescent (TL) phosphor powders have been coated onto fiberoptic cables and remote dosimetry measurements performed using traditional laser heating techniques. The sensitivity is limited by the requirement for a very thin layer of phosphor material, due to problems associated with light scattering and efficient heating by thermal diffusion. In this paper we report the development of an all-optical, fiber-optic-coupled, thermoluminescence dosemeter for remote radiation sensing that offers significant advantages compared to previous technologies. We recently reported the development of an optically transparent, TL glass material having exceptionally good characteristics for traditional dosimetry applications. We also reported a modified TL glass incorporating a rare earth ion dopant in order to absorb light from a semiconductor laser and utilize the absorbed light energy to internally heat the glass and release the trapped electrons. (author)
Dosimetric studies of the eye lens using a new dosemeter – Surveys in interventional radiology departments
International Nuclear Information System (INIS)
During interventional radiology (IR) and cardiology (IC) procedures, medical staff can receive high doses to their eye lenses. The Retrospective Evaluation of Lens Injuries and Dose study organized in Argentina in 2010 found incipient opacity in 50% of IC physicians and 41% of IC technicians/nurses. These results, added to the recommendations of the International Commission on Radiological Protection, which lowered their former occupational equivalent dose limit for the lens, led us to assess the eye lens dose, Hp(3), during interventional procedures. To this end, a new dosemeter was designed and calibrated at the National Atomic Energy Commission of Argentina to evaluate Hp(3). Personal dose equivalent (Hp(10)), and Hp(3) were assessed for 3 months in two IC and IR departments. An Alderson phantom was used to simulate monthly exposures of five occupational staff members. Hp(3) and Hp(10) were obtained monthly for 14 occupational staff members exposed to 121 IR and IC procedures. We concluded that the annual effective dose and Hp(3) were lower than 0.3 and 10 mSv, respectively and the average cumulative Hp(3) for working life was lower than 400 and 200 mSv for physicians and technicians/scrub nurse, respectively. An occupational annual dose constraint of 0.3 mSv was calculated. - Highlights: • An eye lens dosimeters was designed at the Personal Dosimetry Laboratory of CNEA. • A successful dosimetric survey in two interventional departments was done. • The annual effective dose and the annual eye lens dose are lower than the ICRP dose thresholds. • In order to reduce doses actions should be promoted to maximize radiation protection
Developmental and hyperthermia-induced expression of the heat shock proteins HSP60 and HSP70 in tissues of the housefly Musca domestica: an in vitro study
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Sunita Sharma
Full Text Available The expression pattern of two major chaperones, the heat shock proteins (HSPs HSP60 and HSP70 was studied in vitro in tissues of the housefly Musca domestica during larval and adult stages of development to identify their immunological relatives and understand their functional significance in normal cellular activities and during thermal stress. Fluorographs of labeled polypeptides and western blots demonstrated that both HSPs are expressed constitutively and heat-induced in all the larval and adult cell types examined. The pattern of whole tissue immunocytochemical staining using anti-HSP60 and anti-HSP70 antibodies corresponded well with the observations from western blots or fluorographs. In developing oocytes, both constitutive and heat inducible expression of HSP60 were regulated in an oocyte stage-specific manner. In unstressed ovaries the expression of these proteins was less pronounced in early stage oocytes (1st - 8th than at later stages (9th and onward. The heat shock, however, induced both HSP70 and HSP60 to a significantly high level in early stage oocytes (1st-8th as compared to their respective controls. Our findings indicate the involvement of the HSP60 and HSP70 proteins in the development, growth and differentiation of both somatic and germ line tissues. Furthermore, the enhanced co-expression of HSP70 and HSP60 upon heat shock in various larval and adult cell types suggests the possible role of HSP60 in thermoprotection.
Stimulation of TLR4 by recombinant HSP70 requires structural integrity of the HSP70 protein itself
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Luong Michael
Full Text Available Abstract Background Toll-like receptor 4 (TLR4 is activated by bacterial endotoxin, a prototypical pathogen-associated molecular pattern (PAMP. It has been suggested that TLR4 can also be activated by damage-associated molecular pattern (DAMP proteins such as HSP70. It remains a challenge to provide unequivocal evidence that DAMP proteins themselves play a role in TLR4 activation, as the DAMP proteins used are often contaminated with endotoxin and other TLR ligands introduced during protein expression and/or purification. Results Here we report that the activation of TLR4 on primary human macrophage cultures by recombinant HSP70 is not solely due to contaminating endotoxin. Polymyxin B pretreatment of HSP70 preparations to neutralize contaminating endotoxin caused significant reductions in the amount of TNF-α induced by the recombinant protein as determined by ELISA. However, digestion of HSP70 with Proteinase K-agarose beads also dramatically reduced the TNF-α response of macrophages to HSP70, while leaving levels of contaminating endotoxin largely unchanged relative to controls. Conclusions These results indicate that the stimulatory effect of recombinant HSP70 requires both the presence of endotoxin and structural integrity of the heat shock protein itself.
Genome-scale co-evolutionary inference identifies functions and clients of bacterial Hsp90.
Press, Maximilian O; Li, Hui; Creanza, Nicole; Kramer, Günter; Queitsch, Christine; Sourjik, Victor; Borenstein, Elhanan
The molecular chaperone Hsp90 is essential in eukaryotes, in which it facilitates the folding of developmental regulators and signal transduction proteins known as Hsp90 clients. In contrast, Hsp90 is not essential in bacteria, and a broad characterization of its molecular and organismal function is lacking. To enable such characterization, we used a genome-scale phylogenetic analysis to identify genes that co-evolve with bacterial Hsp90. We find that genes whose gain and loss were coordinated with Hsp90 throughout bacterial evolution tended to function in flagellar assembly, chemotaxis, and bacterial secretion, suggesting that Hsp90 may aid assembly of protein complexes. To add to the limited set of known bacterial Hsp90 clients, we further developed a statistical method to predict putative clients. We validated our predictions by demonstrating that the flagellar protein FliN and the chemotaxis kinase CheA behaved as Hsp90 clients in Escherichia coli, confirming the predicted role of Hsp90 in chemotaxis and flagellar assembly. Furthermore, normal Hsp90 function is important for wild-type motility and/or chemotaxis in E. coli. This novel function of bacterial Hsp90 agreed with our subsequent finding that Hsp90 is associated with a preference for multiple habitats and may therefore face a complex selection regime. Taken together, our results reveal previously unknown functions of bacterial Hsp90 and open avenues for future experimental exploration by implicating Hsp90 in the assembly of membrane protein complexes and adaptation to novel environments. PMID:23874229
International Nuclear Information System (INIS)
This report presents an overview of the technologies which are currently used or presently developed for the production of bio-fuels in Europe and more particularly in France. After a brief history of this production since the beginning of the 20. century, the authors describe the support to agriculture and the influence of the Common Agricultural Policy, outline the influence of the present context of struggle against the greenhouse effect, and present the European legislative context. Data on the bio-fuels consumption in the European Union in 2006 are discussed. An overview of the evolution of the activity related to bio-fuels in France, indicating the locations of ethanol and bio-diesel production facilities, and the evolution of bio-fuel consumption, is given. The German situation is briefly presented. Production of ethanol by fermentation, the manufacturing of ETBE, the bio-diesel production from vegetable oils are discussed. Second generation bio-fuels are then presented (cellulose enzymatic processing), together with studies on thermochemical processes and available biomass resources
Dosimetric studies in children and adolescents using thermoluminescence dosemeters following radiation exposure from panoramic dental X-ray units
International Nuclear Information System (INIS)
For the determination of the somatic radiation exposure of children and adolescents by X-ray films with the status X panorama X-ray unit personal dosimetric measurements were carried out by means of thermoluminescence dosemeters (LiF and CaSO4) in 46 patients aged 7 to 16 years. The non-screen film 'ORWO TF 13' and the screen film 'ORWO TF 2' in connection with flexible intensifying screens were used. During the exposure the dosemeters were always fixed at the same measuring points being situated within or outside the mouth of the patient. The maximum radiation exposure was registered at those points where the transparent window of the hollow anode introduced into the mouth of the patient was directly opposite to the palatal and lingual, mucosa resp. With a maxillary or mandibular panorama film and the use of non-screen films doses of 60 to 80 mGy (6 - 8 rd) were determined. Using TF 2 screen films in connection with flexible intensifying screens the values for exposure time and radiation dose could be decreased by more than 50%. Basing on these results not only a strict indication but also the use of intensifying screens have to be required for the performance of radiodiagnostical examination with status X panorama X-ray units. (author)
Influence of the phantom shape (slab, cylinder or Alderson) on the performance of an Hp(3) eye dosemeter
International Nuclear Information System (INIS)
In the past, the operational quantity Hp(3) was defined for calibration purposes in a slab phantom. Recently, an additional phantom in the form of a cylinder has been suggested for eye lens dosimetry, as a cylinder much better approximates the shape of a human head. Therefore, this work investigates which of the two phantoms, slab or cylinder, is more suitable for calibrations and type tests of eye dosemeters. For that purpose, a typical Hp(3) eye dosemeter was irradiated on a slab, a cylinder and on a human-like Alderson phantom. It turned out that the response on the three phantoms is nearly equal for angles of radiation incidence up to 45 deg. and deviates only at larger angles of incidence. Thus, calibrations (usually performed at 0 deg. radiation incidence) are practically equivalent on both the slab and the cylinder phantoms. However, type tests (up to 75 deg. or even 90 deg. radiation incidence) should be carried out on a cylinder phantom, as also for large angles of incidence the response on the cylinder and the Alderson phantoms is rather similar, whereas the response on the slab significantly deviates from the one on the Alderson phantom. (authors)
Calibration of an eye lens dosemeter in terms of Hp(3) to be used in interventional radiology
International Nuclear Information System (INIS)
Recently, the International Commission on Radiological Protection has reviewed epidemiological evidences suggesting that there were tissue reaction effects in the eye lens below the previously considered absorbed dose threshold. A new statement related to the eye lens was issued that changed the absorbed dose threshold and reduced the dose limits for occupationally exposed persons. As consequence, some planned exposures require eye lens dosimetry and a debate was raised on the adequacy of the dosimetric quantity and on its method of measurement. The aim of this work was to study the methodology for calibrating the EYE-DTM holder with a TLD-100H Harshaw chip detector and to determine its angular and energy dependences in terms of personal dose equivalent, Hp(3). - Highlights: • Results of calibration of the eye lens dosemeters, in terms of Hp(3). • The proposal of phantoms and specific dosemeters for eye lens have proved viable. • The tests carried out met the limits of acceptance proposed by ISO. • The good performance of the tests may suggest a reduction in the acceptance limits
ANTI-HSP60 and ANTI-HSP70 antibody levels and micro/ macrovascular complications in type 1 diabetes: the EURODIAB Study
DEFF Research Database (Denmark)
Gruden, G.; Bruno, G.; Chaturvedi, N.;
diabetes is associated with a greatly increased risk of micro- and macrovascular complications. Therefore, we investigated whether anti-HSP60 and anti-HSP70 antibody levels were associated with micro- and macrovascular complications in type 1 diabetic patients. DESIGN: A cross-sectional nested case......-control study from the EURODIAB Study of 531 type 1 diabetic patients was performed. SUBJECTS: Cases (n = 363) were defined as those with one or more complications of diabetes; control subjects (n = 168) were all those with no evidence of any complication. We measured anti-HSP60 and anti-HSP70 antibody levels...... and investigated their cross-sectional associations with diabetic complications. RESULTS: Anti-HSP70 antibody levels were significantly greater in control than in case subjects, whereas anti-HSP60 antibody levels were similar in the two groups. In logistic regression analysis, anti-HSP70 levels in the upper...
The use of albedo neutron dosemeters for the measurement of low doses in mixed photon neutron radiation fields at transport casks for high active waste
International Nuclear Information System (INIS)
Radiation exposure of the police forces accompanying transports of spent fuel elements and high-active waste form reprocessing (HAW) is determined by means of albedo dosemeters. The official dosimetry services use this type of dosemeter to mesure the personal dose in mixed gamma/neutron radiation fields above all for routine monitoring of workers occupationally exposed to radiation. The present report describes the detailed set-up and functioning of the albedo dosemeter, the process of obtaining the photon and neutron personal dose from the detector indications as well as the determination of the detection limit of the total personal dose of the albedo dosemeter according to the methods specified in the valid standards. Determination of the detection limit is based on the experience gained during previous transports, on measurements performed at transport casks, on results of type tests at PTB (Federal Physical and Technical Authority), on the measurement uncertainties obtained from the annual intercomparison measurements of the PTB as well as on the test irradiation specially performed in the range of small neutron and photon doses under laboratory conditions. For the dosimetry systems of the dosimetry services and the specific transport conditions, a reference level of 100 μSv was specified with regard to the dose detection limit. (orig.)
About the measurements systems with pen and thermoluminescent dosemeters; Sobre los sistemas de medicion con dosimetros de pluma y los termoluminiscentes
Energy Technology Data Exchange (ETDEWEB)
Cortes I, M.E.; Ramirez G, F.P. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152. 07730 Mexico D.F. (Mexico)
In this work it is presented dosimetric data obtained with pen and thermoluminescent dosemeters, which are used by the Occupational Exposure Personnel (OEP) of the Mexican Petroleum Institute (IMP)(1). It was marked several great characteristics as for example, the differences among units which use one and another dosemeter type. Likewise, it is given to know diverse problems that were had in the IMP at relating the data obtained with these dosemeters (which utilizes OEP) and the ICRP 60 recommendations 1990. One of the most important difficulties is to satisfy the recommended limits by ICRP, particularly those that are referring to the units and their complex calculations. With respect to the unities, the ICRP makes reference at the concepts `dose equivalent` and `effective dose` with the sievert unit, that the General Regulations for Radiological Safety associates with `dose equivalent` and `effective dose equivalent`. It was illustrated the type of dosimetric statistics which are obtained with the TLD lectures and a OEP pen dosemeter during 1997. (Author)
Response of electret dosemeters to eletrons with energies of 3 MeV, 7 MeV, 11 MeV
International Nuclear Information System (INIS)
The response of the electret dosemeter to electrons of 3,7 and 11 MeV from an accelerator Mevatron 12 is studied. Two external coatings (polyethylene or nylon) are used and a comparative evaluation is presented. (M.A.C.)
Yeast Two-Hybrid and One-Hybrid Screenings Identify Regulators of hsp70 Gene Expression.
Saito, Youhei; Nakagawa, Takanobu; Kakihana, Ayana; Nakamura, Yoshia; Nabika, Tomomi; Kasai, Michihiro; Takamori, Mai; Yamagishi, Nobuyuki; Kuga, Takahisa; Hatayama, Takumi; Nakayama, Yuji
The mammalian stress protein Hsp105β, which is specifically expressed during mild heat shock and localizes to the nucleus, induces the major stress protein Hsp70. In the present study, we performed yeast two-hybrid and one-hybrid screenings to identify the regulators of Hsp105β-mediated hsp70 gene expression. Six and two proteins were detected as Hsp105β- and hsp70 promoter-binding proteins, respectively. A luciferase reporter gene assay revealed that hsp70 promoter activation is enhanced by the transcriptional co-activator AF9 and splicing mediator SNRPE, but suppressed by the coiled-coil domain-containing protein CCDC127. Of these proteins, the knockdown of SNRPE suppressed the expression of Hsp70 irrespective of the presence of Hsp105β, indicating that SNRPE essentially functions as a transcriptional activator of hsp70 gene expression. The overexpression of HSP70 in tumor cells has been associated with cell survival and drug resistance. We here identified novel regulators of Hsp70 expression in stress signaling and also provided important insights into Hsp70-targeted anti-cancer therapy. J. Cell. Biochem. 117: 2109-2117, 2016. © 2016 Wiley Periodicals, Inc. PMID:26873636
Co-expression of heat shock protein (HSP) 40 and HSP70 in Pinctada martensii response to thermal, low salinity and bacterial challenges.
Li, Jun; Zhang, Yuehuan; Liu, Ying; Zhang, Yang; Xiao, Shu; Yu, Ziniu
Heat shock protein (HSP) 40 proteins are a family of molecular chaperones that bind to HSP70 through their J-domain and regulate the function of HSP70 by stimulating its adenosine triphosphatase activity. In the present study, a HSP40 homolog named PmHSP40 was cloned from the hemocytes of pearl oyster Pinctada martensii using EST and rapid amplification of cDNA ends (RACE) techniques. The full-length cDNA of PmHSP40 was 1251 bp in length, which included a 5' untranslated region (UTR) of 75 bp, an open reading frame (ORF) of a 663 bp, and a 3' UTR of 513 bp. The deduced amino acid sequence of PmHSP40 contains a J domain in the N-terminus. In response to thermal and low salinity stress challenges, the expression of PmHSP40 in hemocytes and the gill were inducible in a time-dependent manner. After bacterial challenge, PmHSP40 transcripts in hemocytes increased and peaked at 6 h post injection. In the gill, PmHSP40 expression increased, similar to expression in hemocytes; however, transcript expression of PmHSP40 was significantly up-regulated at 12 h post injection. Furthermore, the transcripts of PmHSP70 showed similar kinetics as that of PmHSP40, with highest induction during thermal, low salinity stress and bacterial challenges. Altogether these results demonstrate that PmHSP40 is an inducible protein under thermal, low salinity and bacterial challenges, suggesting its involvement in both environmental and biological stresses, and in the innate immunity of the pearl oyster. PMID:26679110
In silico identification of carboxylate clamp type tetratricopeptide repeat proteins in Arabidopsis and rice as putative co-chaperones of Hsp90/Hsp70.
Directory of Open Access Journals (Sweden)
Bishun D Prasad
Full Text Available The essential eukaryotic molecular chaperone Hsp90 operates with the help of different co-chaperones, which regulate its ATPase activity and serve as adaptors to recruit client proteins and other molecular chaperones, such as Hsp70, to the Hsp90 complex. Several Hsp90 and Hsp70 co-chaperones contain the tetratricopeptide repeat (TPR domain, which interacts with the highly conserved EEVD motif at the C-terminal ends of Hsp90 and Hsp70. The acidic side chains in EEVD interact with a subset of basic residues in the TPR binding pocket called a 'carboxylate clamp'. Since the carboxylate clamp residues are conserved in the TPR domains of known Hsp90/Hsp70 co-chaperones, we carried out an in silico search for TPR proteins in Arabidopsis and rice comprising of at least one three-motif TPR domain with conserved amino acid residues required for Hsp90/Hsp70 binding. This approach identified in Arabidopsis a total of 36 carboxylate clamp (CC-TPR proteins, including 24 novel proteins, with potential to interact with Hsp90/Hsp70. The newly identified CC-TPR proteins in Arabidopsis and rice contain additional protein domains such as ankyrin, SET, octicosapeptide/Phox/Bem1p (Phox/PB1, DnaJ-like, thioredoxin, FBD and F-box, and protein kinase and U-box, indicating varied functions for these proteins. To provide proof-of-concept of the newly identified CC-TPR proteins for interaction with Hsp90, we demonstrated interaction of AtTPR1 and AtTPR2 with AtHsp90 in yeast two-hybrid and in vitro pull down assays. These findings indicate that the in silico approach used here successfully identified in a genome-wide context CC-TPR proteins with potential to interact with Hsp90/Hsp70, and further suggest that the Hsp90/Hsp70 system relies on TPR co-chaperones more than it was previously realized.
CancerHSP: anticancer herbs database of systems pharmacology
Tao, Weiyang; Li, Bohui; Gao, Shuo; Bai, Yaofei; Shar, Piar Ali; Zhang, Wenjuan; Guo, Zihu; Sun, Ke; Fu, Yingxue; Huang, Chao; Zheng, Chunli; Mu, Jiexin; Pei, Tianli; Wang, Yuan; Li, Yan; Wang, Yonghua
The numerous natural products and their bioactivity potentially afford an extraordinary resource for new drug discovery and have been employed in cancer treatment. However, the underlying pharmacological mechanisms of most natural anticancer compounds remain elusive, which has become one of the major obstacles in developing novel effective anticancer agents. Here, to address these unmet needs, we developed an anticancer herbs database of systems pharmacology (CancerHSP), which records anticancer herbs related information through manual curation. Currently, CancerHSP contains 2439 anticancer herbal medicines with 3575 anticancer ingredients. For each ingredient, the molecular structure and nine key ADME parameters are provided. Moreover, we also provide the anticancer activities of these compounds based on 492 different cancer cell lines. Further, the protein targets of the compounds are predicted by state-of-art methods or collected from literatures. CancerHSP will help reveal the molecular mechanisms of natural anticancer products and accelerate anticancer drug development, especially facilitate future investigations on drug repositioning and drug discovery. CancerHSP is freely available on the web at http://lsp.nwsuaf.edu.cn/CancerHSP.php.
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Energy Technology Data Exchange (ETDEWEB)
Energy from biomass has an amount of nearly 70% in the power generation from renewable energy source. In Germany, the share of bio energy in the energy consumption amounts nearly eight per cent. The contribution reports on the form, utilization and practical examples of application of bio energy under consideration of critical aspects. It also presents possibilities to guarantee a sustainable cultivation of energy crops and the precedence of the production of food stuffs.
Engineering BioBrick vectors from BioBrick parts
Directory of Open Access Journals (Sweden)
Knight Thomas F
Full Text Available Abstract Background The underlying goal of synthetic biology is to make the process of engineering biological systems easier. Recent work has focused on defining and developing standard biological parts. The technical standard that has gained the most traction in the synthetic biology community is the BioBrick standard for physical composition of genetic parts. Parts that conform to the BioBrick assembly standard are BioBrick standard biological parts. To date, over 2,000 BioBrick parts have been contributed to, and are available from, the Registry of Standard Biological Parts. Results Here we extended the same advantages of BioBrick standard biological parts to the plasmid-based vectors that are used to provide and propagate BioBrick parts. We developed a process for engineering BioBrick vectors from BioBrick parts. We designed a new set of BioBrick parts that encode many useful vector functions. We combined the new parts to make a BioBrick base vector that facilitates BioBrick vector construction. We demonstrated the utility of the process by constructing seven new BioBrick vectors. We also successfully used the resulting vectors to assemble and propagate other BioBrick standard biological parts. Conclusion We extended the principles of part reuse and standardization to BioBrick vectors. As a result, myriad new BioBrick vectors can be readily produced from all existing and newly designed BioBrick parts. We invite the synthetic biology community to (1 use the process to make and share new BioBrick vectors; (2 expand the current collection of BioBrick vector parts; and (3 characterize and improve the available collection of BioBrick vector parts.
RNAi knockdown of Hop (Hsp70/Hsp90 organising protein) decreases invasion via MMP-2 down regulation.
Walsh, Naomi; Larkin, AnneMarie; Swan, Niall; Conlon, Kevin; Dowling, Paul; McDermott, Ray; Clynes, Martin
We previously identified Hop as over expressed in invasive pancreatic cancer cell lines and malignant tissues of pancreatic cancer patients, suggesting an important role for Hop in the biology of invasive pancreatic cancer. Hop is a co-chaperone protein that binds to both Hsp70/Hsp90. We hypothesised that by targeting Hop, signalling pathways modulating invasion and client protein stabilisation involving Hsp90-dependent complexes may be altered. In this study, we show that Hop knockdown by small interfering (si)RNA reduces the invasion of pancreatic cancer cells, resulting in decreased expression of the downstream target gene, matrix metalloproteinases-2 (MMP-2). Hop in conditioned media co-immunoprecipitates with MMP-2, implicating a possible extracellular function for Hop. Knockdown of Hop expression also reduced expression levels of Hsp90 client proteins, HER2, Bcr-Abl, c-MET and v-Src. Furthermore, Hop is strongly expressed in high grade PanINs compared to lower PanIN grades, displaying differential localisation in invasive ductal pancreatic cancer, indicating that the localisation of Hop is an important factor in pancreatic tumours. Our data suggests that the attenuation of Hop expression inactivates key signal transduction proteins which may decrease the invasiveness of pancreatic cancer cells possibly through the modulation of Hsp90 activity. Therefore, targeting Hop in pancreatic cancer may constitute a viable strategy for targeted cancer therapy.
真菌HSP30的研究概况%Studies of HSP30 from Fungi
Institute of Scientific and Technical Information of China (English)
陈文静; 陈明; 许亦峰; 施碧红
热休克蛋白30是小分子热休克蛋白(small heat shock proteins,sHSPs)中的一种,也是真菌中研究最广泛的小分子热休克蛋白.多种真菌编码热休克蛋白的基因序列已经被克隆和检测,HSP30的研究主要集中在应激水平下的表达和转录水平的调控,HSP30在应激反应中的合成机制仍不是很清楚,综述了它的研究概况以及应用前景.%Heat shock protein 30 is one of small Heat Shock Proteins (sHSPs), and is being widely investigated in fungi. Genes encoding heat shock protein from different fungi have been cloned and tested.Studies on HSP30 was mainly focus on the expression of stress leves and transcriptional regulation, and the synthesis mechanism of HSP30 under stress response is still unclear. The research progress of HSP30 and its application prospect is reviewed.
RNAi knockdown of Hop (Hsp70/Hsp90 organising protein) decreases invasion via MMP-2 down regulation.
LENUS (Irish Health Repository)
Walsh, Naomi
We previously identified Hop as over expressed in invasive pancreatic cancer cell lines and malignant tissues of pancreatic cancer patients, suggesting an important role for Hop in the biology of invasive pancreatic cancer. Hop is a co-chaperone protein that binds to both Hsp70\\/Hsp90. We hypothesised that by targeting Hop, signalling pathways modulating invasion and client protein stabilisation involving Hsp90-dependent complexes may be altered. In this study, we show that Hop knockdown by small interfering (si)RNA reduces the invasion of pancreatic cancer cells, resulting in decreased expression of the downstream target gene, matrix metalloproteinases-2 (MMP-2). Hop in conditioned media co-immunoprecipitates with MMP-2, implicating a possible extracellular function for Hop. Knockdown of Hop expression also reduced expression levels of Hsp90 client proteins, HER2, Bcr-Abl, c-MET and v-Src. Furthermore, Hop is strongly expressed in high grade PanINs compared to lower PanIN grades, displaying differential localisation in invasive ductal pancreatic cancer, indicating that the localisation of Hop is an important factor in pancreatic tumours. Our data suggests that the attenuation of Hop expression inactivates key signal transduction proteins which may decrease the invasiveness of pancreatic cancer cells possibly through the modulation of Hsp90 activity. Therefore, targeting Hop in pancreatic cancer may constitute a viable strategy for targeted cancer therapy.
Sequence and domain conservation of the coelacanth Hsp40 and Hsp90 chaperones suggests conservation of function.
Bishop, Özlem Tastan; Edkins, Adrienne Lesley; Blatch, Gregory Lloyd
Molecular chaperones and their associated co-chaperones play an important role in preserving and regulating the active conformational state of cellular proteins. The chaperone complement of the Indonesian Coelacanth, Latimeria menadoensis, was elucidated using transcriptomic sequences. Heat shock protein 90 (Hsp90) and heat shock protein 40 (Hsp40) chaperones, and associated co-chaperones were focused on, and homologous human sequences were used to search the sequence databases. Coelacanth homologs of the cytosolic, mitochondrial and endoplasmic reticulum (ER) homologs of human Hsp90 were identified, as well as all of the major co-chaperones of the cytosolic isoform. Most of the human Hsp40s were found to have coelacanth homologs, and the data suggested that all of the chaperone machinery for protein folding at the ribosome, protein translocation to cellular compartments such as the ER and protein degradation were conserved. Some interesting similarities and differences were identified when interrogating human, mouse, and zebrafish homologs. For example, DnaJB13 is predicted to be a non-functional Hsp40 in humans, mouse, and zebrafish due to a corrupted histidine-proline-aspartic acid (HPD) motif, while the coelacanth homolog has an intact HPD. These and other comparisons enabled important functional and evolutionary questions to be posed for future experimental studies.
Atomic structure of Hsp90-Cdc37-Cdk4 reveals that Hsp90 traps and stabilizes an unfolded kinase.
Verba, Kliment A; Wang, Ray Yu-Ruei; Arakawa, Akihiko; Liu, Yanxin; Shirouzu, Mikako; Yokoyama, Shigeyuki; Agard, David A
The Hsp90 molecular chaperone and its Cdc37 cochaperone help stabilize and activate more than half of the human kinome. However, both the mechanism by which these chaperones assist their "client" kinases and the reason why some kinases are addicted to Hsp90 while closely related family members are independent are unknown. Our structural understanding of these interactions is lacking, as no full-length structures of human Hsp90, Cdc37, or either of these proteins with a kinase have been elucidated. Here we report a 3.9 angstrom cryo-electron microscopy structure of the Hsp90-Cdc37-Cdk4 kinase complex. Surprisingly, the two lobes of Cdk4 are completely separated with the β4-β5 sheet unfolded. Cdc37 mimics part of the kinase N lobe, stabilizing an open kinase conformation by wedging itself between the two lobes. Finally, Hsp90 clamps around the unfolded kinase β5 strand and interacts with exposed N- and C-lobe interfaces, protecting the kinase in a trapped unfolded state. On the basis of this structure and an extensive amount of previously collected data, we propose unifying conceptual and mechanistic models of chaperone-kinase interactions. PMID:27339980
Nematode Hsp90: highly conserved but functionally diverse.
Gillan, Victoria; Devaney, Eileen
Nematodes are amongst the most successful and abundant organisms on the planet with approximately 30 000 species described, although the actual number of species is estimated to be one million or more. Despite sharing a relatively simple and invariant body plan, there is considerable diversity within the phylum. Nematodes have evolved to colonize most ecological niches, and can be free-living or can parasitize plants or animals to the detriment of the host organism. In this review we consider the role of heat shock protein 90 (Hsp90) in the nematode life cycle. We describe studies on Hsp90 in the free-living nematode Caenorhabditis elegans and comparative work on the parasitic species Brugia pahangi, and consider whether a dependence upon Hsp90 can be exploited for the control of parasitic species. PMID:24721950
HSP25 Protects Radiation-Induced Salivary Gland Damage
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Lee, Hae June; Lee, Yoon Jin; Kwon, Hee Choong; Lee, Su Jae; Bae, Sang Woo; Lee, Yun Sil [Korea Institute of Radiological Medical Sciences, Seoul (Korea, Republic of); Kim, Sung Ho [Chonnam National Univ., Gwangju (Korea, Republic of)
Irradiation (IR) is a central treatment modality administered for head and neck malignancies. A significant consequence of this IR treatment is irreversible damage to salivary gland in the IR field. While the exact mechanism of salivary gland damage remains enigmatic, fluid secreting acinar cells are lost, and saliva output is dramatically reduced. Previously we have reported that heat shock protein 25 (HSP25) induced radioresistance in vitro. HSP25 interferes negatively with apoptosis through several pathways which involve its direct interaction with cytochrome c, protein kinase c delta or Akt. And localized gene transfer to salivary glands has great potential for the treatment of salivary gland. Herein, we investigated whether HSP25 can use as radio protective molecules for radiation-induced salivary gland damage in vivo.
Hsp90 inhibitors reduce influenza virus replication in cell culture
International Nuclear Information System (INIS)
The viral RNA polymerase complex of influenza A virus consists of three subunits PB1, PB2 and PA. Recently, the cellular chaperone Hsp90 was shown to play a role in nuclear import and assembly of the trimeric polymerase complex by binding to PB1 and PB2. Here we show that Hsp90 inhibitors, geldanamycin or its derivative 17-AAG, delay the growth of influenza virus in cell culture resulting in a 1-2 log reduction in viral titre early in infection. We suggest that this is caused by the reduced half-life of PB1 and PB2 and inhibition of nuclear import of PB1 and PA which lead to reduction in viral RNP assembly. Hsp90 inhibitors may represent a new class of antiviral compounds against influenza viruses
Genome-scale Co-evolutionary Inference Identifies Functions and Clients of Bacterial Hsp90
Press, Maximilian O.; Li, Hui; Creanza, Nicole; Kramer, Günter; Queitsch, Christine; Sourjik, Victor; Borenstein, Elhanan
The molecular chaperone Hsp90 is essential in eukaryotes, in which it facilitates the folding of developmental regulators and signal transduction proteins known as Hsp90 clients. In contrast, Hsp90 is not essential in bacteria, and a broad characterization of its molecular and organismal function is lacking. To enable such characterization, we used a genome-scale phylogenetic analysis to identify genes that co-evolve with bacterial Hsp90. We find that genes whose gain and loss were coordinate...
Mechanistic and Structural Insights into the Prion-Disaggregase Activity of Hsp104.
Sweeny, Elizabeth A; Shorter, James
Hsp104 is a dynamic ring translocase and hexameric AAA+ protein found in yeast, which couples ATP hydrolysis to disassembly and reactivation of proteins trapped in soluble preamyloid oligomers, disordered protein aggregates, and stable amyloid or prion conformers. Here, we highlight advances in our structural understanding of Hsp104 and how Hsp104 deconstructs Sup35 prions. Although the atomic structure of Hsp104 hexamers remains uncertain, volumetric reconstruction of Hsp104 hexamers in ATPγS, ADP-AlFx (ATP hydrolysis transition-state mimic), and ADP via small-angle x-ray scattering has revealed a peristaltic pumping motion upon ATP hydrolysis. This pumping motion likely drives directional substrate translocation across the central Hsp104 channel. Hsp104 initially engages Sup35 prions immediately C-terminal to their cross-β structure. Directional pulling by Hsp104 then resolves N-terminal cross-β structure in a stepwise manner. First, Hsp104 fragments the prion. Second, Hsp104 unfolds cross-β structure. Third, Hsp104 releases soluble Sup35. Deletion of the Hsp104 N-terminal domain yields a hypomorphic disaggregase, Hsp104(∆N), with an altered pumping mechanism. Hsp104(∆N) fragments Sup35 prions without unfolding cross-β structure or releasing soluble Sup35. Moreover, Hsp104(∆N) activity cannot be enhanced by mutations in the middle domain that potentiate disaggregase activity. Thus, the N-terminal domain is critical for the full repertoire of Hsp104 activities. PMID:26608812
Hsp90 Regulates NADPH Oxidase Activity and Is Necessary for Superoxide but Not Hydrogen Peroxide Production
Chen, Feng; Pandey, Deepesh; Chadli, Ahmed; Catravas, John D.; Chen, Teng; Fulton, David J. R.
The goal of this study was to identify whether heat-shock protein 90 (Hsp90) regulates the production of superoxide and other reactive oxygen species from the NADPH oxidases (Nox). We found that pharmacological and genetic inhibition of Hsp90 directly reduced Nox5-derived superoxide without secondarily modifying signaling events. Coimmunoprecipitation and bioluminescence resonance energy transfer studies suggest that the C-terminus of Nox5 binds to Hsp90. Long-term Hsp90 inhibition reduced No...
Inhibition of Hsp27 Radiosensitizes Head-and-Neck Cancer by Modulating Deoxyribonucleic Acid Repair
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Guttmann, David M.; Hart, Lori [Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Du, Kevin [Department of Radiation Oncology, New York University School of Medicine, New York, New York (United States); Seletsky, Andrew [Department of Biology, Drexel University, Philadelphia, Pennsylvania (United States); Koumenis, Constantinos, E-mail: firstname.lastname@example.com [Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania (United States)
Purpose: To present a novel method of tumor radiosensitization through Hsp27 knockdown using locked nucleic acid (LNA) and to investigate the role of Hsp27 in DNA double strand break (DSB) repair. Methods and Materials: Clonogenic survival assays, immunoblotting, the proximity ligation assay, and γH2AX foci analysis were conducted in SQ20B and FaDu human head-and-neck cancer cell lines treated with Hsp27 LNA and Hsp27 short hairpin RNA (shRNA). Additionally, nude mice with FaDu flank tumors were treated with fractionated radiation therapy after pretreatment with Hsp27 LNA and monitored for tumor growth. Results: Hsp27 LNA and Hsp27 shRNA radiosensitized head-and-neck cancer cell lines in an Hsp27-dependent manner. Ataxia-Telangectasia Mutated-mediated DNA repair signaling was impaired in irradiated cells with Hsp27 knockdown. ATM kinase inhibition abrogated the radiosensitizing effect of Hsp27. Furthermore, Hsp27 LNA and shRNA both attenuated DNA repair kinetics after radiation, and Hsp27 was found to colocalize with ATM in both untreated and irradiated cells. Last, combined radiation and Hsp27 LNA treatment in tumor xenografts in nude mice suppressed tumor growth compared with either treatment alone. Conclusions: These results support a radiosensitizing property of Hsp27 LNA in vitro and in vivo, implicate Hsp27 in double strand break repair, and suggest that Hsp27 LNA might eventually serve as an effective clinical agent in the radiotherapy of head-and-neck cancer.
Phenotypic diversity and altered environmental plasticity in Arabidopsis thaliana with reduced Hsp90 levels.
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Todd A Sangster
Full Text Available The molecular chaperone HSP90 aids the maturation of a diverse but select set of metastable protein clients, many of which are key to a variety of signal transduction pathways. HSP90 function has been best investigated in animal and fungal systems, where inhibition of the chaperone has exceptionally diverse effects, ranging from reversing oncogenic transformation to preventing the acquisition of drug resistance. Inhibition of HSP90 in the model plant Arabidopsis thaliana uncovers novel morphologies dependent on normally cryptic genetic variation and increases stochastic variation inherent to developmental processes. The biochemical activity of HSP90 is strictly conserved between animals and plants. However, the substrates and pathways dependent on HSP90 in plants are poorly understood. Progress has been impeded by the necessity of reliance on light-sensitive HSP90 inhibitors due to redundancy in the A. thaliana HSP90 gene family. Here we present phenotypic and genome-wide expression analyses of A. thaliana with constitutively reduced HSP90 levels achieved by RNAi targeting. HSP90 reduction affects a variety of quantitative life-history traits, including flowering time and total seed set, increases morphological diversity, and decreases the developmental stability of repeated characters. Several morphologies are synergistically affected by HSP90 and growth temperature. Genome-wide expression analyses also suggest a central role for HSP90 in the genesis and maintenance of plastic responses. The expression results are substantiated by examination of the response of HSP90-reduced plants to attack by caterpillars of the generalist herbivore Trichoplusia ni. HSP90 reduction potentiates a more robust herbivore defense response. In sum, we propose that HSP90 exerts global effects on the environmental responsiveness of plants to many different stimuli. The comprehensive set of HSP90-reduced lines described here is a vital instrument to further examine
Modelling the role of the Hsp70/Hsp90 system in the maintenance of protein homeostasis.
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Carole J Proctor
Full Text Available Neurodegeneration is an age-related disorder which is characterised by the accumulation of aggregated protein and neuronal cell death. There are many different neurodegenerative diseases which are classified according to the specific proteins involved and the regions of the brain which are affected. Despite individual differences, there are common mechanisms at the sub-cellular level leading to loss of protein homeostasis. The two central systems in protein homeostasis are the chaperone system, which promotes correct protein folding, and the cellular proteolytic system, which degrades misfolded or damaged proteins. Since these systems and their interactions are very complex, we use mathematical modelling to aid understanding of the processes involved. The model developed in this study focuses on the role of Hsp70 (IPR00103 and Hsp90 (IPR001404 chaperones in preventing both protein aggregation and cell death. Simulations were performed under three different conditions: no stress; transient stress due to an increase in reactive oxygen species; and high stress due to sustained increases in reactive oxygen species. The model predicts that protein homeostasis can be maintained during short periods of stress. However, under long periods of stress, the chaperone system becomes overwhelmed and the probability of cell death pathways being activated increases. Simulations were also run in which cell death mediated by the JNK (P45983 and p38 (Q16539 pathways was inhibited. The model predicts that inhibiting either or both of these pathways may delay cell death but does not stop the aggregation process and that eventually cells die due to aggregated protein inhibiting proteasomal function. This problem can be overcome if the sequestration of aggregated protein into inclusion bodies is enhanced. This model predicts responses to reactive oxygen species-mediated stress that are consistent with currently available experimental data. The model can be used to
Ratio of phosphorylated HSP27 to nonphosphorylated HSP27 biphasically acts as a determinant of cellular fate in gemcitabine-resistant pancreatic cancer cells.
Kang, Dongxu; Choi, Hye Jin; Kang, Sujin; Kim, So Young; Hwang, Yong-Sic; Je, Suyeon; Han, Zhezhu; Kim, Joo-Hang; Song, Jae J
Gemcitabine has been used most commonly as an anticancer drug to treat advanced pancreatic cancer patients. However, intrinsic or acquired resistance of pancreatic cancer to gemcitabine was also developed, which leads to very low five-year survival rates. Here, we investigated whether cellular levels of HSP27 phosphorylation act as a determinant of cellular fate with gemcitabine. In addition we have demonstrated whether HSP27 downregulation effectively could overcome the acquisition of gemcitabine resistance by using transcriptomic analysis. We observed that gemcitabine induced p38/HSP27 phosphorylation and caused acquired resistance. After acquisition of gemcitabine resistance, cancer cells showed higher activity of NF-κB. NF-κB activity, as well as colony formation in gemcitabine-resistant pancreatic cancer cells, was significantly decreased by HSP27 downregulation and subsequent TRAIL treatment, showing that HSP27 was a common network mediator of gemcitabine/TRAIL-induced cell death. After transcriptomic analysis, gene fluctuation after HSP27 downregulation was very similar to that of pancreatic cancer cells susceptible to gemcitabine, and then in opposite position to that of acquired gemcitabine resistance, which makes it possible to downregulate HSP27 to overcome the acquired gemcitabine resistance to function as an overall survival network inhibitor. Most importantly, we demonstrated that the ratio of phosphorylated HSP27 to nonphosphorylated HSP27 rather than the cellular level of HSP27 itself acts biphasically as a determinant of cellular fate in gemcitabine-resistant pancreatic cancer cells.
Stability of the human Hsp90-p50Cdc37 chaperone complex against nucleotides and Hsp90 inhibitors, and the influence of phosphorylation by casein kinase 2.
Olesen, Sanne H; Ingles, Donna J; Zhu, Jin-Yi; Martin, Mathew P; Betzi, Stephane; Georg, Gunda I; Tash, Joseph S; Schönbrunn, Ernst
The molecular chaperone Hsp90 is regulated by co-chaperones such as p50Cdc37, which recruits a wide selection of client protein kinases. Targeted disruption of the Hsp90-p50Cdc37 complex by protein-protein interaction (PPI) inhibitors has emerged as an alternative strategy to treat diseases characterized by aberrant Hsp90 activity. Using isothermal microcalorimetry, ELISA and GST-pull down assays we evaluated reported Hsp90 inhibitors and nucleotides for their ability to inhibit formation of the human Hsp90β-p50Cdc37 complex, reconstituted in vitro from full-length proteins. Hsp90 inhibitors, including the proposed PPI inhibitors gedunin and H2-gamendazole, did not affect the interaction of Hsp90 with p50Cdc37 in vitro. Phosphorylation of Hsp90 and p50Cdc37 by casein kinase 2 (CK2) did not alter the thermodynamic signature of complex formation. However, the phosphorylated complex was vulnerable to disruption by ADP (IC50 = 32 µM), while ATP, AMPPNP and Hsp90 inhibitors remained largely ineffective. The differential inhibitory activity of ADP suggests that phosphorylation by CK2 primes the complex for dissociation in response to a drop in ATP/ADP levels. The approach applied herein provides robust assays for a comprehensive biochemical evaluation of potential effectors of the Hsp90-p50Cdc37 complex, such as phosphorylation by a kinase or the interaction with small molecule ligands.
Stability of the Human Hsp90-p50Cdc37 Chaperone Complex against Nucleotides and Hsp90 Inhibitors, and the Influence of Phosphorylation by Casein Kinase 2
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Sanne H. Olesen
Full Text Available The molecular chaperone Hsp90 is regulated by co-chaperones such as p50Cdc37, which recruits a wide selection of client protein kinases. Targeted disruption of the Hsp90-p50Cdc37 complex by protein–protein interaction (PPI inhibitors has emerged as an alternative strategy to treat diseases characterized by aberrant Hsp90 activity. Using isothermal microcalorimetry, ELISA and GST-pull down assays we evaluated reported Hsp90 inhibitors and nucleotides for their ability to inhibit formation of the human Hsp90β-p50Cdc37 complex, reconstituted in vitro from full-length proteins. Hsp90 inhibitors, including the proposed PPI inhibitors gedunin and H2-gamendazole, did not affect the interaction of Hsp90 with p50Cdc37 in vitro. Phosphorylation of Hsp90 and p50Cdc37 by casein kinase 2 (CK2 did not alter the thermodynamic signature of complex formation. However, the phosphorylated complex was vulnerable to disruption by ADP (IC50 = 32 µM, while ATP, AMPPNP and Hsp90 inhibitors remained largely ineffective. The differential inhibitory activity of ADP suggests that phosphorylation by CK2 primes the complex for dissociation in response to a drop in ATP/ADP levels. The approach applied herein provides robust assays for a comprehensive biochemical evaluation of potential effectors of the Hsp90-p50Cdc37 complex, such as phosphorylation by a kinase or the interaction with small molecule ligands.
Stability of the Human Hsp90-p50Cdc37 Chaperone Complex against Nucleotides and Hsp90 Inhibitors, and the Influence of Phosphorylation by Casein Kinase 2
Olesen, Sanne H.; Ingles, Donna J.; Zhu, Jin-Yi; Martin, Mathew P.; Betzi, Stephane; Georg, Gunda I.; Tash, Joseph S.; Schönbrunn, Ernst
The molecular chaperone Hsp90 is regulated by co-chaperones such as p50Cdc37, which recruits a wide selection of client protein kinases. Targeted disruption of the Hsp90-p50Cdc37 complex by protein-protein interaction (PPI) inhibitors has emerged as an alternative strategy to treat diseases characterized by aberrant Hsp90 activity. Using isothermal microcalorimetry, ELISA and GST-pull down assays we evaluated reported Hsp90 inhibitors and nucleotides for their ability to inhibit formation of the human Hsp90β-p50Cdc37 complex, reconstituted in-vitro from full-length proteins. Hsp90 inhibitors, including the proposed PPI inhibitors gedunin and H2-gamendazole, did not affect the interaction of Hsp90 with p50Cdc37 in vitro. Phosphorylation of Hsp90 and p50Cdc37 by casein kinase 2 (CK2) did not alter the thermodynamic signature of complex formation. However, the phosphorylated complex was vulnerable to disruption by ADP (IC50 = 32 µM), while ATP, AMPPNP and Hsp90 inhibitors remained largely ineffective. The differential inhibitory activity of ADP suggests that phosphorylation by CK2 primes the complex for dissociation in response to a drop in ATP/ADP levels. The approach applied herein provides robust assays for a comprehensive biochemical evaluation of potential effectors of the Hsp90-p50Cdc37 complex, such as phosphorylation by a kinase or the interaction with small molecule ligands. PMID:25608045
Constitutively-active androgen receptor variants function independently of the HSP90 chaperone but do not confer resistance to HSP90 inhibitors.
Gillis, Joanna L; Selth, Luke A; Centenera, Margaret M; Townley, Scott L; Sun, Shihua; Plymate, Stephen R; Tilley, Wayne D; Butler, Lisa M
The development of lethal, castration resistant prostate cancer is associated with adaptive changes to the androgen receptor (AR), including the emergence of mutant receptors and truncated, constitutively active AR variants. AR relies on the molecular chaperone HSP90 for its function in both normal and malignant prostate cells, but the requirement for HSP90 in environments with aberrant AR expression is largely unknown. Here, we investigated the efficacy of three HSP90 inhibitors, 17-AAG, HSP990 and AUY922, against clinically-relevant AR missense mutants and truncated variants. HSP90 inhibition effectively suppressed the signaling of wild-type AR and all AR missense mutants tested. By contrast, two truncated AR variants, AR-V7 and ARv567es, exhibited marked resistance to HSP90 inhibitors. Supporting this observation, nuclear localization of the truncated AR variants was not affected by HSP90 inhibition and AR variant:HSP90 complexes could not be detected in prostate cancer cells. Interestingly, HSP90 inhibition resulted in accumulation of AR-V7 and ARv567es in both cell lines and human tumor explants. Despite the apparent independence of AR variants from HSP90 and their treatment-associated induction, the growth of cell lines with endogenous or enforced expression of AR-V7 or ARv567es remained highly sensitive to AUY922. This study demonstrates that functional AR variant signaling does not confer resistance to HSP90 inhibition, yields insight into the interaction between AR and HSP90 and provides further impetus for the clinical application of HSP90 inhibitors in advanced prostate cancer.
Expression of HSP72 in the gastric mucosa is regulated by gastric acid in rats-Correlation of HSP72 expression with mucosal protection
International Nuclear Information System (INIS)
Background and aim: The real mechanism of adaptive cytoprotection in the gastric mucosa is not well established. In the present study, we investigated the effect of acid suppressing agents on a 72-kDa heat shock protein (HSP72) expression, which is known as endogenous cytoprotective factor, in the gastric mucosa. Also, the association of gastric mucosal protective function against HCl-challenge was compared between HSP72-induced and -reduced group. Materials and methods: Expression of HSP72 was measured by Western blotting in the gastric mucosa before and after administration of famotidine or omeprazole. The gastric mucosal protective function against 0.6 N HCl was compared between control group and HSP72-reduced group. Also, the effect of increased expression of gastric HSP72 by additional administration of zinc sulfate or zinc L-carnosine, which is known as HSP72-inducer, on mucosal protective function was studied. Results: HSP72 expression in the gastric mucosa was reduced by acid suppressing agents. The lowest expression level of HSP72 was observed 12 h (famotidine, H2-receptor antagonist) or 48 h (omeprazole, proton pump inhibitor) after administration. The gastric mucosal protective ability against 0.6 N HCl was also reduced when HSP72 expression was decreased by famotidine or omeprazole. This phenomenon was reversed by HSP72 induction by additional administration of zinc derivatives. Conclusion: Our results might indicate that the expression of HSP72 in the gastric mucosa is physiologically regulated by gastric acid, and that HSP72 induction could be important in view of mucosal protection especially when HSP72 expression is reduced by administration of acid suppressing agents such as proton pump inhibitor or H2 receptor antagonist
Neonatal Death and Heart Failure in Mouse with Transgenic HSP60 Expression
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Tsung-Hsien Chen
Full Text Available Mitochondrial heat shock proteins, such as HSP60, are chaperones responsible for the folding, transport, and quality control of mitochondrial matrix proteins and are essential for maintaining life. Both prosurvival and proapoptotic roles have been proposed for HSP60, and HSP60 is reportedly involved in the initiation of autoimmune, metabolic, and cardiovascular diseases. The role of HSP60 in pathogenesis of these diseases remains unclear, partly because of the lack of mouse models expressing HSP60. In this study we generated HSP60 conditional transgenic mice suitable for investigating in vivo outcomes by expressing HSP60 at the targeted organ in disease models. Ubiquitous HSP60 induction in the embryonic stage caused neonatal death in mice at postnatal day 1. A high incidence of atrial septal defects was observed in HSP60-expressing mice, with increased apoptosis and myocyte degeneration that possibly contributed to massive hemorrhage and sponge-like cardiac muscles. Our results showed that neonatal heart failure through HSP60 induction likely involves developmental defects and excessive apoptosis. The conditional HSP60 mouse model is useful for studying crucial biological questions concerning HSP60.
Conserved structure and expression of hsp70 paralogs in teleost fishes
DEFF Research Database (Denmark)
Metzger, David C.H.; Hansen, Jakob Hemmer; Schulte, Patricia M.
fish. Phylogenetic and synteny analyses indicate that hsp70-1 and hsp70-2 are distinct paralogs that originated prior to the diversification of the teleosts. The promoters of both genes contain a TATA box and conserved heat shock elements (HSEs), but unlike mammalian HSP70s, both genes contain...
Hsp70 stabilizes lysosomes and reverts Niemann-Pick disease-associated lysosomal pathology
DEFF Research Database (Denmark)
Kirkegaard, Thomas; Roth, Anke G; Petersen, Nikolaj H T;
. In acidic environments Hsp70 binds with high affinity and specificity to BMP, thereby facilitating the BMP binding and activity of acid sphingomyelinase (ASM). The inhibition of the Hsp70-BMP interaction by BMP antibodies or a point mutation in Hsp70 (Trp90Phe), as well as the pharmacological and genetic...
Heat shock protein 70 (Hsp70) stimulates proliferation and cytolytic activity of natural killer cells
Multhoff, G; Mizzen, L; Winchester, CC; Milner, CM; Wenk, S; Eissner, G; Kampinga, HH; Laumbacher, B; Johnson, J
We previously demonstrated that lysis of tumor cells that express Hsp70, the highly stress-inducible member of the HSP70 family, on their plasma membrane is mediated by natural killer (NK) cells. Here, we studied the effects of different proteins of the HSP70 family in combination with interleukin 2
Expression of Hsp27 and Hsp70 in Lymphocytes and Plasma in Healthy Workers and Coal Miners with Lung Cancer
Institute of Scientific and Technical Information of China (English)
王海椒; 邢景才; 王峰; 韩文慧; 任侯卯; 邬堂春; 陈卫红
In coal mines, main occupational hazard is coal-mine dust, which can cause health problem including coal workers' pneumoconiosis and lung cancer. Some heat shock proteins (Hsps) have been reported as an acute response to a wide variety of stressful stimuli. Whether Hsps protect against chronic environmental coal-mine dust over years is unknown. It is also interesting to know that whether the expression of Hsp27 and Hsp70 proteins as a marker for exposure is associated risk of lung cancer among coal miners. ...
Several techniques for improving energy dependence of a commercial personal neutron dosemeter package based on PADC track detector
International Nuclear Information System (INIS)
The practical applicability of several techniques has been investigated for improving the energy dependence of PADC-based personal neutron dosemeter for a commercial dose-assessment service. Under a constraint of no modification in detector material and the fixed chemical processes, two technical attempts have been investigated: an analysis of etch-pit data obtained by microscopic observation and a design of radiator structure. In addition to the number of etch-pits, information of their distribution in terms of various parameters was analyzed. It was found that the two-window method was possibly applicable to the distribution in the etch-pit size and the gray-level. In the latter, a performance of radiator-degrader structure has been confirmed experimentally, and it was found to be one of most promising techniques.
Absorbed dose measurements in mammography using Monte Carlo method and ZrO{sub 2}+PTFE dosemeters
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Duran M, H. A.; Hernandez O, M. [Departamento de Investigacion en Polimeros y Materiales, Universidad de Sonora, Blvd. Luis Encinas y Rosales s/n, Col. Centro, 83190 Hermosillo, Sonora (Mexico); Salas L, M. A.; Hernandez D, V. M.; Vega C, H. R. [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Pinedo S, A.; Ventura M, J.; Chacon, F. [Hospital General de Zona No. 1, IMSS, Interior Alameda 45, 98000 Zacatecas (Mexico); Rivera M, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, IPN, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D. F.(Mexico)], e-mail: firstname.lastname@example.com
Mammography test is a central tool for breast cancer diagnostic. In addition, programs are conducted periodically to detect the asymptomatic women in certain age groups; these programs have shown a reduction on breast cancer mortality. Early detection of breast cancer is achieved through a mammography, which contrasts the glandular and adipose tissue with a probable calcification. The parameters used for mammography are based on the thickness and density of the breast, their values depend on the voltage, current, focal spot and anode-filter combination. To achieve an image clear and a minimum dose must be chosen appropriate irradiation conditions. Risk associated with mammography should not be ignored. This study was performed in the General Hospital No. 1 IMSS in Zacatecas. Was used a glucose phantom and measured air Kerma at the entrance of the breast that was calculated using Monte Carlo methods and ZrO{sub 2}+PTFE thermoluminescent dosemeters, this calculation was completed with calculating the absorbed dose. (author)
Improvement and calibration of a SSNT personal dosemeter and study of importance of albedo factor for dose calculation
International Nuclear Information System (INIS)
The Neutriran albedo neutron dosemeter has been improved and calibrated for neutron personal dosimetry. The Monte Carlo code MCNP4b was used to calculate the thermal neutrons backscattered from the body (albedo factor). Backscattering from the wall, ceiling and floor in calibration room was considered also via simulation by MCNP4C. A semi automated counting system applying a high-resolution scanner was used for counting of tracks. An 241Am source was used to produce similar alpha particles from 10B (n,α) 7Li reaction for the optimisation of scanner parameters to distinguish and separate the tracks in SSNTD, which lead to a better distinction between etched alpha tracks and, consequently, a higher linear region of dose characteristic. (authors)
Application of workplace correction factors to dosemeter results for the assessment of personal doses at nuclear facilities
International Nuclear Information System (INIS)
Ratios of Hp(10) and H*(10) were determined with reference instruments in a number of workplace fields within the nuclear industry and used to derive workplace-specific correction factors. When commercial survey meter results together with these factors were applied to the results of the locally used personal dosemeters their results improved and became within 0.7 and 1.7 of the reference values or better depending on the response of the survey meter. A similar result was obtained when a correction was determined with a prototype reference instrument for Hp(10) after adjustment of its response. Commercially available survey instruments both for photon and neutron H*(10) measurements agreed with the reference instruments in most cases to within 0.5-1.5. Those conclusions are derived from results reported within the EC supported EVIDOS contract. (authors)
A Modification of Gamma Surveymeter Dosemeter 3007A for Monitoring Use Ethernet by PLC T100MD Series
International Nuclear Information System (INIS)
It has been modified a gamma surveymeter Dosemeter 3007A. The Surveymeter represents analogous surveymeter, so that an interface for data acquisition is required. Acquisition system from surveymeter is added to the voltage amplifier module from 0 - 200 mV to 0 - 5 V. This voltage value will represent of doses 0 - 5 mR/hour. Hereinafter the analogous signal 0 - 5 V as signal of input to peripheral of PLC T100MD series. Data in the form of processed analogous signal presented at local display of PLC. For long distance monitoring, data have been sent to a computer from PLC by ethernet. After this modification, the surveymeter can be used to monitor from long distance. By using Internet Service Provider, monitoring can be done at any time and any where as long as network internet is available. (author)
Performance of the electronic personal dosemeter for neutron 'Saphydose-N' at different workplaces of nuclear facilities.
Lahaye, T; Chau, Q; Ménard, S; Lacoste, V; Muller, H; Luszik-Bhadra, M; Reginatto, M; Bruguier, P
This paper mainly aims at presenting the measurements and the results obtained with the electronic personal neutron dosemeter Saphydose-N at different facilities. Three campaigns were led in the frame of the European contract EVIDOS ('Evaluation of Individual Dosimetry in Mixed Neutron and Photon Radiation Fields'). The first one consisted in the measurements at the IRSN French research laboratory in reference neutron fields generated by a thermal facility (SIGMA), radionuclide ISO sources ((241)AmBe; (252)Cf; (252)Cf(D(2)O)\\Cd) and a realistic spectrum (CANEL/T400). The second one was performed at the Krümmel Nuclear Power Plant (Germany) close to the boiling water reactor and to a spent fuel transport cask. The third one was realised at Mol (Belgium), at the VENUS Research Reactor and at Belgonucléaire, a fuel processing factory.
Spatio-temporal regulation of Hsp90-ligand complex leads to immune activation.
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Yasuaki eTamura
Full Text Available Hsp90 is the most abundant cytosolic HSP and is known to act as a molecular chaperone. We found that an Hsp90-cancer antigen peptide complex was efficiently cross-presented by human monocyte-derived dendritic cells and induced peptide-specific cytotoxic T lymphocytes. Furthermore, we observed that the internalized Hsp90-peptide complex was strictly sorted to the Rab5+, EEA1+ static early endosome and the Hsp90-chaperoned peptide was processed and bound to MHC class I molecules through a endosome-recycling pathway. We also found that extracellular Hsp90 complexed with CpG-A or self-DNA stimulates production of a large amount of IFN-α from pDCs via static early endosome targeting. Thus, extracellular Hsp90 can target the antigen or nucleic acid to a static early endosome by spatio-temporal regulation. Moreover, we showed that Hsp90 associates with and delivers TLR7/9 from the ER to early endosomes for ligand recognition. Hsp90 inhibitor, geldanamycin derivative inhibited the Hsp90 association with TLR7/9, resulting in inhibition IFN-α production, leading to improvement of SLE symptoms. Interstingly, we observed that serum Hsp90 is clearly increased in patients with active SLE compared with that in patients with inactive disease. Serum Hsp90 detected in SLE patients binds to self-DNA and/or anti-DNA Ab, thus leading to stimulation of pDCs to produce IFN-α. Thus, Hsp90 plays a crucial role in the pathogenesis of SLE and that an Hsp90 inhibitor will therefore provide a new therapeutic approach to SLE and other nucleic acid-related autoimmune diseases. We will discuss how spatio-temporal regulation of Hsp90-ligand complexes within antigen-presenting cells affects the innate immunity and adaptive immunity.
Measurements of non-target organ doses using MOSFET dosemeters for selected IMRT and 3D CRT radiation treatment procedures.
Wang, Brian; Xu, X George
Many expressed concerns about the potential increase in second cancer risk from the widespread shift to intensity-modulated radiation therapy (IMRT) techniques from traditional 3-D conformal radiation treatment (3D CRT). This paper describes the study on in-phantom measurements of radiation doses in organ sites away from the primary tumour target. The measurements involved a RANDO((R)) phantom and Metal Oxide Semiconductor Field Effect Transistor dosemeters for selected 3D CRT and IMRT treatment plans. Three different treatment plans, 4-field 3D CRT, 6-field 3D CRT and 7-field IMRT for the prostate, were considered in this study. Steps to reconstruct organ doses from directly measured data were also presented. The dosemeter readings showed that the doses decrease as the distances increase for all treatment plans. At 40 cm from the prostate target, doses were <1% of the therapeutic dose. At this location, however, the IMRT plan resulted in an absorbed dose from photons, that is a factor of 3-5 higher than the 3D CRT treatment plans. This increase on absorbed dose is due to the increased exposure time for delivering the IMRT plan. The total monitor unit (MU) was 2850 for the IMRT case, while the MU was 1308 and 1260 for 6-field and 4-field 3D CRT cases, respectively. Findings from this case study involving the prostate treatments agree with those from previous studies that IMRT indeed delivers higher photon doses to locations that are away from the primary target. PMID:17627959
Use of a robotic manipulator in the simulation of the automation of a calibration process of dosemeters; Uso de un manipulador robotico en la simulacion de la automatizacion de un proceso de calibracion de dosimetros
Energy Technology Data Exchange (ETDEWEB)
Benitez R, J.S.; Najera H, M.C. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)
The development of a system based in a manipulative robot which simulates the operative sequence in a calibration process of dosemeters is presented. In this process it is performed the monitoring of the dosemeter positions and the calibrator by mean of an arm of articulated robot which develops the movement sequences and the taking a decision based on the information coming from the external sensors. (Author)
DEFF Research Database (Denmark)
Hediger, M. R.; Martinez, K. L.; Nygård, J.;
Biosensors based on nanowire field effect transistor (FET) have received much attention in recent years as a way to achieve ultra-sensitive and label-free sensing of molecules of biological interest. The BioFET-SIM computer model permits the analysis and interpretation of experimental sensor...... signals through its web-based interface www.biofetsim.org. The model also allows for predictions of the effects of changes in the experimental setup on the sensor signal. After an introduction to nanowire-based FET biosensors, this chapter reviews the theoretical basis of BioFET-SIM models describing both...... single and multiple charges on the analyte. Afterwards the usage of the interface and its relative command line version is briefly shown. Finally, possible applications of the BioFET-SIM model are presented. Among the possible uses of the interface, the effects on the predicted signal of pH, buffer ionic...
Specific Binding of Tetratricopeptide Repeat Proteins to Heat Shock Protein 70 (Hsp70) and Heat Shock Protein 90 (Hsp90) Is Regulated by Affinity and Phosphorylation.
Assimon, Victoria A; Southworth, Daniel R; Gestwicki, Jason E
Heat shock protein 70 (Hsp70) and heat shock protein 90 (Hsp90) require the help of tetratricopeptide repeat (TPR) domain-containing cochaperones for many of their functions. Each monomer of Hsp70 or Hsp90 can interact with only a single TPR cochaperone at a time, and each member of the TPR cochaperone family brings distinct functions to the complex. Thus, competition for TPR binding sites on Hsp70 and Hsp90 appears to shape chaperone activity. Recent structural and biophysical efforts have improved our understanding of chaperone-TPR contacts, focusing on the C-terminal EEVD motif that is present in both chaperones. To better understand these important protein-protein interactions on a wider scale, we measured the affinity of five TPR cochaperones, CHIP, Hop, DnaJC7, FKBP51, and FKBP52, for the C-termini of four members of the chaperone family, Hsc70, Hsp72, Hsp90α, and Hsp90β, in vitro. These studies identified some surprising selectivity among the chaperone-TPR pairs, including the selective binding of FKBP51/52 to Hsp90α/β. These results also revealed that other TPR cochaperones are only able to weakly discriminate between the chaperones or between their paralogs. We also explored whether mimicking phosphorylation of serine and threonine residues near the EEVD motif might impact affinity and found that pseudophosphorylation had selective effects on binding to CHIP but not other cochaperones. Together, these findings suggest that both intrinsic affinity and post-translational modifications tune the interactions between the Hsp70 and Hsp90 proteins and the TPR cochaperones.
Photon energy response of luminescence dosemeters and its impact on assessment of Hp(10) and Hp(0.07) in mixed fields of varying energies of photons and beta radiation.
Pradhan, A S
X and gamma rays continue to remain the main contributors to the dose to humans. As these photons of varying energies are encountered in various applications, the study of photon energy response of a dosemeter is an important aspect to ensure the accuracy in dose measurement. Responses of dosemeters have to be experimentally established because for luminescence dosemeters, they depend not only on the effective atomic number (ratio of mass energy absorption coefficients of dosemeter and tissue) of the detector, but also considerably on the luminescence efficiency and the material surrounding the dosemeters. Metal filters are generally used for the compensation of energy dependence below 200 keV and/or to provide photon energy discrimination. It is noted that the contribution to Hp(0.07) could be measured more accurately than Hp(10). For the dosemeters exhibiting high photon energy-dependent response, estimation of the beta component of Hp(0.07) becomes very difficult in the mixed field of beta radiation and photons of energy less than 100 keV. Recent studies have shown that the thickness and the atomic number of metal filters not only affect the response below 200 keV but also cause a significant over-response for high energy (>6 MeV) photons often encountered in the environments of pressurised heavy water reactors and accelerators. PMID:12382729
The molecular characterization and expression of heat shock protein 90 (Hsp90) and 26 (Hsp26) cDNAs in sea cucumber (Apostichopus japonicus)
Zhao, Huan; Yang, Hongsheng; Zhao, Heling; Chen, Muyan; Wang, Tianming
The heat shock proteins (HSPs) are a family of proteins whose expression is enhanced in response to environmental stressors. The Apostichopus japonicus hsp90 and hsp26 genes were cloned using expressed sequence tag and rapid amplification of cDNA ends techniques. The full-length cDNA of Aphsp90 and Aphsp26 contains 3,458 and 1,688 nucleotides encoding 720 and 236 amino acids, respectively. Multiple alignments indicated that the deduced amino acid sequences of ApHsp90 and ApHsp26 shared a high...
Bos indicus cattle possess greater basal concentrations of HSP27, alpha B-crystallin, and HSP70 in skeletal muscle in vivo compared with cattle.
Mullins, C R; Zerby, H N; Fitzpatrick, L A; Parker, A J
The objectives of the present study were to evaluate the basal concentrations of heat shock proteins (HSP) between and cattle and to determine if HSP basal concentrations change as an animal matures. A total of 40 cattle were used in a 2 × 2 factorial design to evaluate the effects of genotype and age (heifers and mature cows) on basal concentrations of heat shock protein 27 (HSP27), α B-crystallin (Cryab), and heat shock protein 70 (HSP70). Each experimental group of 10 animals was sampled on a separate day over a period of 4 wk during July 2014. A muscle sample was collected from the longissimus thoracis (LT) and concentrations of HSP were quantified using ELISA. There were no significant differences in HSP concentration for the interaction between age and genotype or for age alone. cattle had greater ( cattle. The results of this study show that basal in vivo HSP concentrations differ between and cattle. However, further studies are needed to investigate the relationship between HSP concentrations and meat tenderness with respect to genotypes to see if HSP concentrations account for at least some variability in tenderness differences.
The Double-Edged Sword: Conserved Functions of Extracellular Hsp90 in Wound Healing and Cancer
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Hance, Michael W.; Nolan, Krystal D.; Isaacs, Jennifer S., E-mail: email@example.com [Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Hollings Cancer Center, Charleston, SC 29412 (United States)
Heat shock proteins (Hsps) represent a diverse group of chaperones that play a vital role in the protection of cells against numerous environmental stresses. Although our understanding of chaperone biology has deepened over the last decade, the "atypical" extracellular functions of Hsps have remained somewhat enigmatic and comparatively understudied. The heat shock protein 90 (Hsp90) chaperone is a prototypic model for an Hsp family member exhibiting a duality of intracellular and extracellular functions. Intracellular Hsp90 is best known as a master regulator of protein folding. Cancers are particularly adept at exploiting this function of Hsp90, providing the impetus for the robust clinical development of small molecule Hsp90 inhibitors. However, in addition to its maintenance of protein homeostasis, Hsp90 has also been identified as an extracellular protein. Although early reports ascribed immunoregulatory functions to extracellular Hsp90 (eHsp90), recent studies have illuminated expanded functions for eHsp90 in wound healing and cancer. While the intended physiological role of eHsp90 remains enigmatic, its evolutionarily conserved functions in wound healing are easily co-opted during malignancy, a pathology sharing many properties of wounded tissue. This review will highlight the emerging functions of eHsp90 and shed light on its seemingly dichotomous roles as a benevolent facilitator of wound healing and as a sinister effector of tumor progression.
Institute of Scientific and Technical Information of China (English)
Objective To investigate the protective effects of heat shock protein 2700(Hsp27)on cis- platin inducing cytotoxicity in a temperature mutant SV40 large T antigen transformed rat embryo fibroblast (P1-Hsp27). Methods The cytotoxical effects of cisplatin on the proliferation status of P1-Hsp27 cells in the presence or absence of Hsp27 were measured by MTT assay. Results Cisplatin possessed dose-dependent cyto- toxicity on P1-Hsp27 cells. 48h after treatment, about 50% cells were dead in those cells exposed to 200μmol cisplatin. However, no obvious protective effects of Hsp27 on cisplatin induced cytotoxicity could be observed (P>0.05),except in those cells exposed to 500μmol cisplatin 12h after treatment. Conclusion Hsp27 has no obvious protective effects on cisplatin inducing cytotoxicity.
Expression of HSP70 family and HSP90 family in skeletal muscles of transport stressed pigs%运输应激猪骨骼肌中热应激蛋白HSP70和HSP90家族的表达
Institute of Scientific and Technical Information of China (English)
鲍恩东; Sultan,KR; 等
To demonstrate the expression of heat shock protein s(HSP)in skeletal muscles and to estimate the relationship between expression of HSP and pork quality, using Western blot four kinds of HSP which belongs to HSP70 family and HSP90 family respectively in porcine skeletal muscle tissues were determined after a long distance transport.All four HSP,namely HSP70,HSP72,HSP86 and HSP90,were regularly detected in M.longissimus dorsi and M.gluteus medius of both the transported and the cont rol group.The expression of HSP in control pigs showed that HSPs have some indep endent physiological from stress response undetermined functions.after 6 h trans port,the induction of the HSP70 and HSP72 in skeletal muscle tissues was slightly elevated(P>0.05).However,expression of the HSP 86 and the HSP90,especially HSP90,markedly decreased(P<0.01)in skelet al muscles.The results are implied that the reduction tendency of HSP90 fa mily is relative to pork quality and may serve as a potential marker for stress response.%利用Western blot技术,检测长途运输试验猪骨骼肌(背最长肌和臀大肌)中分属于HSP70家族和HSP90家族的4种应激蛋白(HSP70,HSP 72,HSP86和HSP90)的表达。所有运输应激猪和对照猪肌肉组织中均检测到了上述4种HSP。对照猪组织中HSP的表达说明HSP除了在受应激的细胞内行使生理功能外,还具有独立于应激刺激应答以外的其它作用。6 h的长途运输后,HSP的表达量明显不同,HSP70和HSP72在肌肉组织中的表达虽然有一定的增加,但统计学分析差异不显著(P>0.05);而HSP86和HSP90在骨骼肌中的表达明显下降,尤以HS P90下降最为显著(P<0.01)。提示HSP90家族成员与肉品品质相关,可能作为判断应激损伤的指征。
Genome-scale co-evolutionary inference identifies functions and clients of bacterial Hsp90.
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Maximilian O Press
Full Text Available The molecular chaperone Hsp90 is essential in eukaryotes, in which it facilitates the folding of developmental regulators and signal transduction proteins known as Hsp90 clients. In contrast, Hsp90 is not essential in bacteria, and a broad characterization of its molecular and organismal function is lacking. To enable such characterization, we used a genome-scale phylogenetic analysis to identify genes that co-evolve with bacterial Hsp90. We find that genes whose gain and loss were coordinated with Hsp90 throughout bacterial evolution tended to function in flagellar assembly, chemotaxis, and bacterial secretion, suggesting that Hsp90 may aid assembly of protein complexes. To add to the limited set of known bacterial Hsp90 clients, we further developed a statistical method to predict putative clients. We validated our predictions by demonstrating that the flagellar protein FliN and the chemotaxis kinase CheA behaved as Hsp90 clients in Escherichia coli, confirming the predicted role of Hsp90 in chemotaxis and flagellar assembly. Furthermore, normal Hsp90 function is important for wild-type motility and/or chemotaxis in E. coli. This novel function of bacterial Hsp90 agreed with our subsequent finding that Hsp90 is associated with a preference for multiple habitats and may therefore face a complex selection regime. Taken together, our results reveal previously unknown functions of bacterial Hsp90 and open avenues for future experimental exploration by implicating Hsp90 in the assembly of membrane protein complexes and adaptation to novel environments.
Identification and in silico analysis of the Citrus HSP70 molecular chaperone gene family
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Luciano G. Fietto
Full Text Available The completion of the genome sequencing of the Arabidopsis thaliana model system provided a powerful molecular tool for comparative analysis of gene families present in the genome of economically relevant plant species. In this investigation, we used the sequences of the Arabidopsis Hsp70 gene family to identify and annotate the Citrus Hsp70 genes represented in the CitEST database. Based on sequence comparison analysis, we identified 18 clusters that were further divided into 5 subgroups encoding four mitochondrial mtHsp70s, three plastid csHsp70s, one ER luminal Hsp70 BiP, two HSP110/SSE-related proteins and eight cytosolic Hsp/Hsc70s. We also analyzed the expression profile by digital Northern of each Hsp70 transcript in different organs and in response to stress conditions. The EST database revealed a distinct population distribution of Hsp70 ESTs among isoforms and across the organs surveyed. The Hsp70-5 isoform was highly expressed in seeds, whereas BiP, mitochondrial and plastid HSp70 mRNAs displayed a similar expression profile in the organs analyzed, and were predominantly represented in flowers. Distinct Hsp70 mRNAs were also differentially expressed during Xylella infection and Citrus tristeza viral infection as well as during water deficit. This in silico study sets the groundwork for future investigations to fully characterize functionally the Citrus Hsp70 family and underscores the relevance of Hsp70s in response to abiotic and biotic stresses in Citrus.
Tumor imaging and targeting potential of an Hsp70-derived 14-mer peptide.
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Mathias Gehrmann
Full Text Available BACKGROUND: We have previously used a unique mouse monoclonal antibody cmHsp70.1 to demonstrate the selective presence of a membrane-bound form of Hsp70 (memHsp70 on a variety of leukemia cells and on single cell suspensions derived from solid tumors of different entities, but not on non-transformed cells or cells from corresponding 'healthy' tissue. This antibody can be used to image tumors in vivo and target them for antibody-dependent cellular cytotoxicity. Tumor-specific expression of memHsp70 therefore has the potential to be exploited for theranostic purposes. Given the advantages of peptides as imaging and targeting agents, this study assessed whether a 14-mer tumor penetrating peptide (TPP; TKDNNLLGRFELSG, the sequence of which is derived from the oligomerization domain of Hsp70 which is expressed on the cell surface of tumor cells, can also be used for targeting membrane Hsp70 positive (memHsp70+ tumor cells, in vitro. METHODOLOGY/PRINCIPAL FINDINGS: The specificity of carboxy-fluorescein (CF- labeled TPP (TPP to Hsp70 was proven in an Hsp70 knockout mammary tumor cell system. TPP specifically binds to different memHsp70+ mouse and human tumor cell lines and is rapidly taken up via endosomes. Two to four-fold higher levels of CF-labeled TPP were detected in MCF7 (82% memHsp70+ and MDA-MB-231 (75% memHsp70+ cells compared to T47D cells (29% memHsp70+ that exhibit a lower Hsp70 membrane positivity. After 90 min incubation, TPP co-localized with mitochondrial membranes in memHsp70+ tumors. Although there was no evidence that any given vesicle population was specifically localized, fluorophore-labeled cmHsp70.1 antibody and TPP preferentially accumulated in the proximity of the adherent surface of cultured cells. These findings suggest a potential association between membrane Hsp70 expression and cytoskeletal elements that are involved in adherence, the establishment of intercellular synapses and/or membrane reorganization. CONCLUSIONS
DEFF Research Database (Denmark)
Grodal, Torben Kragh
The article argues on the basis of analyses of successful films for children that not only cultural determinants but also innate determinats are important, and that film studies should combine cultural studies with cognitive theory, evolutionary theory and neuroscience, an approach that is called...... Bio-culturalism....
Urban, Gerald A
Explosive growth in the field of Microsystem Technology has introduced a variety of promising products in major disciplines from microelectronics to life sciences. 'Biomes' is a discipline which focuses on microsystems for living systems. This work presents the exciting field of bio-microsystems.
Bio-technologies; Biotechnologies
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Grawitz, X. [Systems Bio Industries, 92 - Boulogne Billancourt (France)
This paper is a series of transparencies which describes the measures taken by Systems Bio-Industries company to adapt its central heating plants, turbines, engines and dryers to the new French 2910 by-law about thermal efficiency and environmental impact of heating plants. The project of development of a cogeneration system in the Angouleme site is briefly described. (J.S.)
Combination of Correctors Rescue ΔF508-CFTR by Reducing Its Association with Hsp40 and Hsp27.
Lopes-Pacheco, Miquéias; Boinot, Clément; Sabirzhanova, Inna; Morales, Marcelo M; Guggino, William B; Cebotaru, Liudmila
Correcting the processing of ΔF508-CFTR, the most common mutation in cystic fibrosis, is the major goal in the development of new therapies for this disease. Here, we determined whether ΔF508 could be rescued by a combination of small-molecule correctors, and identified the mechanism by which correctors rescue the trafficking mutant of cystic fibrosis transmembrane conductance regulator (CFTR). We transfected COS-7 cells with ΔF508, created HEK-293 stably expressing ΔF508, and utilized CFBE41o(-) cell lines stably transduced with ΔF508. As shown previously, ΔF508 expressed less protein, was unstable at physiological temperature, and rapidly degraded. When the cells were treated with the combination C18 + C4 the mature C-band was expressed at the cell surface. After treatment with C18 + C4, we saw a lower rate of protein disappearance after translation was stopped with cycloheximide. To understand how this rescue occurs, we evaluated the change in the binding of proteins involved in endoplasmic reticulum-associated degradation, such as Hsp27 (HspB1) and Hsp40 (DnaJ). We saw a dramatic reduction in binding to heat shock proteins 27 and 40 following combined corrector therapy. siRNA experiments confirmed that a reduction in Hsp27 or Hsp40 rescued CFTR in the ΔF508 mutant, but the rescue was not additive or synergistic with C4 + 18 treatment, indicating these correctors shared a common pathway for rescue involving a network of endoplasmic reticulum-associated degradation proteins.
Role of membrane Hsp70 in radiation sensitivity of tumor cells
International Nuclear Information System (INIS)
The major stress-inducible heat shock protein 70 (Hsp70) is frequently overexpressed in the cytosol and integrated in the plasma membrane of tumor cells via lipid anchorage. Following stress such as non-lethal irradiation Hsp70 synthesis is up-regulated. Intracellular located Hsp70 is known to exert cytoprotective properties, however, less is known about membrane (m)Hsp70. Herein, we investigate the role of mHsp70 in the sensitivity towards irradiation in tumor sublines that differ in their cytosolic and/or mHsp70 levels. The isogenic human colon carcinoma sublines CX+ with stable high and CX− with stable low expression of mHsp70 were generated by fluorescence activated cell sorting, the mouse mammary carcinoma sublines 4 T1 (4 T1 ctrl) and Hsp70 knock-down (4 T1 Hsp70 KD) were produced using the CRISPR/Cas9 system, and the Hsp70 down-regulation in human lung carcinoma sublines H1339 ctrl/H1339 HSF-1 KD and EPLC-272H ctrl/EPLC-272H HSF-1 KD was achieved by small interfering (si)RNA against Heat shock factor 1 (HSF-1). Cytosolic and mHsp70 was quantified by Western blot analysis/ELISA and flow cytometry; double strand breaks (DSBs) and apoptosis were measured by flow cytometry using antibodies against γH2AX and real-time PCR (RT-PCR) using primers and antibodies directed against apoptosis related genes; and radiation sensitivity was determined using clonogenic cell surviving assays. CX+/CX− tumor cells exhibited similar cytosolic but differed significantly in their mHsp70 levels, 4 T1 ctrl/4 T1 Hsp70 KD cells showed significant differences in their cytosolic and mHsp70 levels and H1339 ctrl/H1339 HSF-1 KD and EPLC-272H ctrl/EPLC-272H HSF-1 KD lung carcinoma cell sublines had similar mHsp70 but significantly different cytosolic Hsp70 levels. γH2AX was significantly up-regulated in irradiated CX− and 4 T1 Hsp70 KD with low basal mHsp70 levels, but not in their mHsp70 high expressing counterparts, irrespectively of their cytosolic Hsp70 content. After
Evaluation of neutron doses received at different organs in radiotherapy treatments using the UAB PADC based dosemeters in an anthropomorphic phantom
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Domingo, C., E-mail: firstname.lastname@example.com [Grup de Fisica de les Radiacions, Departament de Fisica, Edifici C, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Garcia-Fuste, M.J.; Morales, E.; Amgarou, K.; Castelo, J. [Grup de Fisica de les Radiacions, Departament de Fisica, Edifici C, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Sanchez-Doblado, F. [Hospital Universitario Virgen Macarena, Servicio de Radiofisica, Sevilla (Spain); Departamento de Fisiologia Medica y Biofisica, Facultad de Medicina, Universidad de Sevilla (Spain)
The NEUTOR project was set up to study radiotherapy patient exposures to the neutrons produced around the LINAC accelerator head by photon radiation above approx8 MeV. These neutrons may reach the patient directly, or they may interact with the surrounding materials until they become thermalised, scattering all over the treatment room and affecting the patient as well. A miniaturised version of the UAB PADC based neutron dosemeter is used, together with thermoluminescence Li-6/Li-7 pairs, in several positions inside an anthropomorphic female phantom to determine doses received by the patient at several organs or tissues. Irradiations were made at a 15 MV LINAC (Hospital Universitario Virgen de la Macarena, Sevilla, Spain), an 18 MV LINAC (Hospital General Universitario de Valencia, Spain) and a 23 MV LINAC (Universitaetsklinikum Heidelberg, Germany). Preliminary patient dose maps obtained from the UAB PADC dosemeter measurements (considering an average calibration factor for all neutron energies) are reported in this work.
Linares, Robert; Doering, Patrick; Linares, Bryant
The use of diamond for advanced applications has been the dream of mankind for centuries. Until recently this dream has been realized only in the use of diamond for gemstones and abrasive applications where tons of diamonds are used on an annual basis. Diamond is the material system of choice for many applications, but its use has historically been limited due to the small size, high cost, and inconsistent (and typically poor) quality of available diamond materials until recently. The recent development of high quality, single crystal diamond crystal growth via the Chemical Vapor Deposition (CVD) process has allowed physcists and increasingly scientists in the life science area to think beyond these limitations and envision how diamond may be used in advanced applications ranging from quantum computing, to power generation and molecular imaging, and eventually even diamond nano-bots. Because of diamond's unique properties as a bio-compatible material, better understanding of diamond's quantum effects and a convergence of mass production, semiconductor-like fabrication process, diamond now promises a unique and powerful key to the realization of the bio-electronic devices being envisioned for the new era of medical science. The combination of robust in-the-body diamond based sensors, coupled with smart bio-functionalized diamond devices may lead to diamond being the platform of choice for bio-electronics. This generation of diamond based bio-electronic devices would contribute substantially to ushering in a paradigm shift for medical science, leading to vastly improved patient diagnosis, decrease of drug development costs and risks, and improved effectiveness of drug delivery and gene therapy programs through better timed and more customized solutions. PMID:19745488
Impact of seropositivity to Chlamydia pneumoniae and anti-hHSP60 on cardiovascular events in hemodialysis patients
Esposito, Pasquale; Tinelli, Carmine; Libetta, Carmelo; Gabanti, Elisa; Rampino, Teresa; Dal Canton, Antonio
Autoimmunity to heat shock protein 60 (HSP60) has been related to atherosclerosis. Chlamydia pneumoniae (CP), the most studied infectious agent implicated in promoting atherosclerosis, produces a form of HSP60, which can induce an autoimmune response, due to high antigenic homology with human HSP60 (hHSP60). In this study, we evaluated the correlations among anti-hHSP60 antibodies, CP infection, and cardiovascular disease (CVD) in a high-risk population, such as patients undergoing hemodialys...
Determination of the dose index in computerized tomography using thermoluminescent dosemeters; Determinacion del indice de dosis en tomografia computada usando dosimetros termoluminiscentes
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Azorin, J.C.; Calderon, A. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-IPN, 11500 Mexico D.F. (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)
In this work the obtained results of the determination of the dose index are presented in thorax studies in computed tomography and helical tomography carried out in Mexico using thermoluminescent dosemeters of LiF: Mg,Cu,P + Ptfe developed and manufactured in our country. The results showed that under similar conditions of irradiation and operation (pitch = 1), significant differences don't exist among the doses absorbed measures in the phantom due to the two types of used tomographs. (Author)
MCNP SIMULATION OF THE HP(10) ENERGY RESPONSE OF A BRAZILIAN TLD ALBEDO NEUTRON INDIVIDUAL DOSEMETER, FROM THERMAL TO 20 MeV.
Freitas, B M; Martins, M M; Pereira, W W; da Silva, A X; Mauricio, C L P
The Brazilian Instituto de Radioproteção e Dosimetria (IRD) runs a neutron individual monitoring system with a home-made TLD albedo dosemeter. It has already been characterised and calibrated in some reference fields. However, the complete energy response of this dosemeter is not known, and the calibration factors for all monitored workplace neutron fields are difficult to be obtained experimentally. Therefore, to overcome such difficulties, Monte Carlo simulations have been used. This paper describes the simulation of the HP(10) neutron response of the IRD TLD albedo dosemeter using the MCNPX transport code, for energies from thermal to 20 MeV. The validation of the MCNPX modelling is done comparing the simulated results with the experimental measurements for ISO standard neutron fields of (241)Am-Be, (252)Cf, (241)Am-B and (252)Cf(D2O) and also for (241)Am-Be source moderated with paraffin and silicone. Bare (252)Cf are used for normalisation. PMID:26276807
Cloning and Expression of a Cytosolic HSP90 Gene in Chlorella vulgaris
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Zhengyi Liu
Full Text Available Heat shock protein 90 (HSP90, a highly conserved molecular chaperone, plays essential roles in folding, keeping structural integrity, and regulating the subset of cytosolic proteins. We cloned the cDNA of Chlorella vulgaris HSP90 (named CvHSP90 by combining homology cloning with rapid amplification of cDNA ends (RACE. Sequence analysis indicated that CvHSP90 is a cytosolic member of the HSP90 family. Quantitative RT-PCR was applied to determine the expression level of messenger RNA (mRNA in CvHSP90 under different stress conditions. C. vulgaris was kept in different temperatures (5–45°C for 1 h. The mRNA expression level of CvHSP90 increased with temperature from 5 to 10°C, went further from 35 to 40°C, and reached the maximum at 40°C. On the other hand, for C. vulgaris kept at 35°C for different durations, the mRNA expression level of CvHSP90 increased gradually and reached the peak at 7 h and then declined progressively. In addition, the expression level of CvHSP90 at 40 or 45 in salinity (‰ was almost fourfold of that at 25 in salinity (‰ for 2 h. Therefore, CvHSP90 may be a potential biomarker to monitor environment changes.
Calcium Homeostasis and Muscle Energy Metabolism Are Modified in HspB1-Null Mice
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Brigitte Picard
Full Text Available Hsp27—encoded by HspB1—is a member of the small heat shock proteins (sHsp, 12–43 kDa (kilodalton family. This protein is constitutively present in a wide variety of tissues and in many cell lines. The abundance of Hsp27 is highest in skeletal muscle, indicating a crucial role for muscle physiology. The protein identified as a beef tenderness biomarker was found at a crucial hub in a functional network involved in beef tenderness. The aim of this study was to analyze the proteins impacted by the targeted invalidation of HspB1 in the Tibialis anterior muscle of the mouse. Comparative proteomics using two-dimensional gel electrophoresis revealed 22 spots that were differentially abundant between HspB1-null mice and their controls that could be identified by mass spectrometry. Eighteen spots were more abundant in the muscle of the mutant mice, and four were less abundant. The proteins impacted by the absence of Hsp27 belonged mainly to calcium homeostasis (Srl and Calsq1, contraction (TnnT3, energy metabolism (Tpi1, Mdh1, PdhB, Ckm, Pygm, ApoA1 and the Hsp proteins family (HspA9. These data suggest a crucial role for these proteins in meat tenderization. The information gained by this study could also be helpful to predict the side effects of Hsp27 depletion in muscle development and pathologies linked to small Hsps.
The Invalidation of HspB1 Gene in Mouse Alters the Ultrastructural Phenotype of Muscles.
Kammoun, Malek; Picard, Brigitte; Astruc, Thierry; Gagaoua, Mohammed; Aubert, Denise; Bonnet, Muriel; Blanquet, Véronique; Cassar-Malek, Isabelle
Even though abundance of Hsp27 is the highest in skeletal muscle, the relationships between the expression of HspB1 (encoding Hsp27) and muscle characteristics are not fully understood. In this study, we have analysed the effect of Hsp27 inactivation on mouse development and phenotype. We generated a mouse strain devoid of Hsp27 protein by homologous recombination of the HspB1 gene. The HspB1-/- mouse was viable and fertile, showing neither apparent morphological nor anatomical alterations. We detected a gender dimorphism with marked effects in males, a lower body weight (P optical microscopy and transmission electron microscopy. Not any differences in the characteristics of muscle fibres (contractile and metabolic type, shape, perimeter, cross-sectional area) were detected except a trend for a higher proportion of small fibres. Different myosin heavy chains electrophoretic profiles were observed in the HspB1-/- mouse especially the presence of an additional isoform. Electron microscopy revealed ultrastructural abnormalities in the myofibrillar structure of the HspB1-/- mouse mutant mice (e.g. destructured myofibrils and higher gaps between myofibrils) especially in the m. Soleus. Combined with our previous data, these findings suggest that Hsp27 could directly impact the organization of muscle cytoskeleton at the molecular and ultrastructural levels. PMID:27512988
A novel biomarker for marine environmental pollution of HSP90 from Mytilus coruscus.
Liu, Huihui; Wu, Jiong; Xu, Mengshan; He, Jianyu
Heat shock protein 90 (HSP90) is a conserved molecular chaperone contributing to cell cycle control, organism development and the proper regulation of cytosolic proteins. The full-length HSP90 cDNA of Mytilus coruscus (McHSP90, KT946644) was 2420bp, including an ORF of 2169bp encoding a polypeptide of 722 amino acids with predicted pI/MW 4.89/83.22kDa. BLASTp analysis and phylogenetic relationship strongly suggested McHSP90 was a member of HSP90 family, and it was highly conserved with other known HSP90, especially in the HSP90 family signatures, ATP/GTP-Binding sites and 'EEVD' motif. The mRNA of McHSP90 in haemolymph was upregulated in all treatments including Vibrio alginolyticus and Vibrio harveyi challenge, metals stresses (copper and cadmium) and 180 CST fuel exposure. All the results implied the expression of McHSP90 could be affected by Vibrio challenge and environmental stress, which might help us gain more insight into the molecular mechanism of HSP against adverse stresses in mollusca.
Molecular cloning and characterization of the full-length Hsp90 gene from Matricaria recutita.
Ling, S P; Su, S S; Zhang, H M; Zhang, X S; Liu, X Y; Pan, G F; Yuan, Y
Heat shock protein 90 (Hsp90) is one of the most abundant and conserved chaperone proteins and plays important roles in plant growth and responses to environmental stimuli. However, little is known regarding the sequence and function of Hsp90s in Matricaria recutita. In the present study, we cloned the full-length cDNA sequence of the hsp90 gene from this species. Using rapid amplification of cDNA ends technologies with 2 degenerate primers that were designed based on the hsp90 gene sequence from other members of Asteraceae, we isolated and characterized an Hsp90 homolog gene from M. recutita (Mr-Hsp90). The full-length Mr-hsp90 cDNA sequence, containing 2097 base pairs, encodes a protein of 698 amino acids. Based on amino acid sequence identity, Mr-Hsp90 showed high similarity to other cloned Hsp90 proteins. The Mr-Hsp90 protein was closely clustered with the Lactuca sativa in a phylogenetic tree. These results indicate that the cloned sequence of Mr-Hsp90 is a member of the Hsp90 family, which is reported for the first time in M. recutita. Next, we conducted a salt stress experiment to determine the protein's function under salt stress conditions. Survival of chamomile seedlings subjected to heat-shock pretreatment was significantly increased compared with groups that had not undergone heat-shock pretreatment in a salt stress environment. This indicates that Mr-Hsp90 plays an important role in the salt resistance of chamomile seedlings. PMID:25526220
Cell stress promotes the association of phosphorylated HspB1 with F-actin.
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Joseph P Clarke
Full Text Available Previous studies have suggested that the small heat shock protein, HspB1, has a direct influence on the dynamics of cytoskeletal elements, in particular, filamentous actin (F-actin polymerization. In this study we have assessed the influence of HspB1 phosphorylation on its interaction(s with F-actin. We first determined the distribution of endogenous non-phosphorylated HspB1, phosphorylated HspB1 and F-actin in neuroendocrine PC12 cells by immunocytochemistry and confocal microscopy. We then investigated a potential direct interaction between HspB1 with F-actin by precipitating F-actin directly with biotinylated phalloidin followed by Western analyses; the reverse immunoprecipitation of HspB1 was also carried out. The phosphorylation influence of HspB1 in this interaction was investigated by using pharmacologic inhibition of p38 MAPK. In control cells, HspB1 interacts with F-actin as a predominantly non-phosphorylated protein, but subsequent to stress there is a redistribution of HspB1 to the cytoskeletal fraction and a significantly increased association of pHspB1 with F-actin. Our data demonstrate HspB1 is found in a complex with F-actin both in phosphorylated and non-phosphorylated forms, with an increased association of pHspB1 with F-actin after heat stress. Overall, our study combines both cellular and biochemical approaches to show cellular localization and direct demonstration of an interaction between endogenous HspB1 and F-actin using methodolgy that specifically isolates F-actin.
Hsp90 is a direct target of the anti-allergic drugs disodium cromoglycate and amlexanox.
Okada, Miki; Itoh, Hideaki; Hatakeyama, Takashi; Tokumitsu, Hiroshi; Kobayashi, Ryoji
Hsp90 (heat-shock protein 90) alone can act to prevent protein aggregation and promote refolding in vitro, but in vivo it operates as a part of a multichaperone complex, which includes Hsp70 and cohort proteins. Since the physiological function of Hsp90 is not yet fully understood, the development of specific antagonists might open new lines of investigation on the role of Hsp90. In an effort to discover Hsp90 antagonists, we screened many drugs and found that the anti-allergic drugs DSCG (disodium cromoglycate) and amlexanox target Hsp90. Both drugs were found to bind directly wild-type Hsp90 via the N- and C-terminal domains. Both drugs strongly suppressed the in vitro chaperone activity of native Hsp90 towards citrate synthase at 1.5-3.0 microM. Amlexanox suppressed C-terminal chaperone activity in vitro, but not N-terminal chaperone activity, and inhibited the association of cohort proteins, such as cyclophilin 40 and Hsp-organizing protein, to the C-terminal domain of Hsp90. These data suggest that amlexanox might disrupt the multichaperone complex, including Hsp70 and cohort proteins, both in vitro and in vivo. Although DSCG inhibited the in vitro chaperone activity of the N-terminal domain, the drug had no effect either on the C-terminal chaperone activity or on the association of the cohort proteins with the C-terminus of Hsp90. The physiological significance of these interactions in vivo remains to be investigated further, but undoubtedly must be taken into account when considering the pharmacology of anti-allergic drugs. DSCG and amlexanox may serve as useful tools for evaluating the physiological significance of Hsp90. PMID:12803546
Heterologous expression of the Hsp24 from Trichoderma asperellum improves antifungal ability of Populus transformant Pdpap-Hsp24 s to Cytospora chrysosperma and Alternaria alternate.
Ji, S D; Wang, Z Y; Fan, H J; Zhang, R S; Yu, Z Y; Wang, J J; Liu, Z H
The tolerance of plants to biotic and abiotic stresses could be improved by transforming with fungal resistance-related genes. In this study, the cDNA sequence (GenBank Acc. No. KP337939) of the resistance-related gene Hsp24 encoding the 24 kD heat shock protein was obtained from the biocontrol fungus Trichoderma asperellum ACCC30536. The promoter region of Hsp24 contained many cis-regulators related to stresses response, such as "GCN4" and "GCR1" etc. Hsp24 transcription in T. asperellum was up-regulated under six different environmental stresses, compared with the control. Furthermore, following heterologous transformation into Populus davidiana × P. alba var. Pyramidalis (Pdpap), Hsp24 was successfully transcribed in transformant Pdpap-Hsp24s. Pathogen-related genes (PRs) in four Pdpap-Hsp24s were up-regulated compared with those in the control Pdpap (Pdpap-Con). After co-culture of Pdpap-Hsp24s with the weak parasite Cytospora chrysosperma, the transcription of genes related to hormone signal pathway (JA and SA) were up-regulated in Pdpap-Hsp24s, and ethidium bromide (EtBr) and Nitro-blue tetrazolium (NBT) staining assays indicated that the cell membrane permeability and the active oxygen content of Pdpap-Hsp24s leaves were lower than that of the control Pdpap-Con. And when the Pdpap-Hsp24s were under the Alternaria alternate stress, the activities of superoxide dismutase (SOD) and peroxidase (POD) got higher in Pdpap-Hsp24s than that in Pdpap-Con, and the disease spots in Pdpap-Con leaves were obviously larger than those in Pdpap-Hsp24s leaves. In summary, Hsp24 of T. asperellum ACCC30536 is an important defense response gene, and its heterologous expression improved the resistance of transformant Pdpap-Hsp24s to C. chrysosperma and A. alternate. PMID:27193371
Activation of phospholipase A2 by Hsp70 in vitro
DEFF Research Database (Denmark)
Mahalka, Ajay K; Code, Christian; Rezaijahromi, Behnam;
We recently suggested a novel mechanism for the activation of phospholipase A2 (PLA2), with a (catalytically) highly active oligomeric state, which subsequently becomes inactivated by conversion into amyloid. This process can be activated by lysophosphatidylcholine which promotes both oligomeriza......We recently suggested a novel mechanism for the activation of phospholipase A2 (PLA2), with a (catalytically) highly active oligomeric state, which subsequently becomes inactivated by conversion into amyloid. This process can be activated by lysophosphatidylcholine which promotes both...... oligomerization and amyloid activation/inactivation. The heat shock protein 70 (Hsp70), has been demonstrated to be able to revert the conversion of a-synuclein and Alzheimer ß-peptide to amyloid fibrils in vitro. Accordingly, we would expect Hsp70 to sustain the lifetime of the active state of the enzyme...
Regulation of Hsp70 function by nucleotide-exchange factors
Gowda, Naveen Kumar Chandappa
Protein folding is the process in which polypeptides in their non-native states attain the unique folds of their native states. Adverse environmental conditions and genetic predisposition challenge the folding process and accelerate the production of proteotoxic misfolded proteins. Misfolded proteins are selectively recognized and removed from the cell by processes of protein quality control (PQC). In PQC molecular chaperones of the Heat shock protein 70 kDa (Hsp70) family play important role...
Low sequence identity but high structural and functional conservation: The case of Hsp70/Hsp90 organizing protein (Hop/Sti1) of Leishmania braziliensis.
Batista, Fernanda A H; Seraphim, Thiago V; Santos, Clelton A; Gonzaga, Marisvanda R; Barbosa, Leandro R S; Ramos, Carlos H I; Borges, Júlio C
Parasites belonging to the genus Leishmania are subjected to extensive environmental changes during their life cycle; molecular chaperones/co-chaperones act as protagonists in this scenario to maintain cellular homeostasis. Hop/Sti1 is a co-chaperone that connects the Hsp90 and Hsp70 systems, modulating their ATPase activities and affecting the fate of client proteins because it facilitates their transfer from the Hsp70 to the Hsp90 chaperone. Hop/Sti1 is one of the most prevalent co-chaperones, highlighting its importance despite the relatively low sequence identity among orthologue proteins. This multi-domain protein comprises three tetratricopeptides domains (TPR1, TPR2A and TPR2B) and two Asp/Pro-rich domains. Given the importance of Hop/Sti1 for the chaperone system and for Leishmania protozoa viability, the Leishmania braziliensis Hop (LbHop) and a truncated mutant (LbHop(TPR2AB)) were characterized. Structurally, both proteins are α-helix-rich and highly elongated monomeric proteins. Functionally, they inhibited the ATPase activity of Leishmania braziliensis Hsp90 (LbHsp90) to a similar extent, and the thermodynamic parameters of their interactions with LbHsp90 were similar, indicating that TPR2A-TPR2B forms the functional center for the LbHop interaction with LbHsp90. These results highlight the structural and functional similarity of Hop/Sti1 proteins, despite their low sequence conservation compared to the Hsp70 and Hsp90 systems, which are phylogenetic highly conserved.
Experimentally guided structural modeling and dynamics analysis of Hsp90-p53 interactions: allosteric regulation of the Hsp90 chaperone by a client protein.
Blacklock, Kristin; Verkhivker, Gennady M
A fundamental role of the Hsp90 chaperone system in mediating maturation of protein clients is essential for the integrity of signaling pathways involved in cell cycle control and organism development. Molecular characterization of Hsp90 interactions with client proteins is fundamental to understanding the activity of many tumor-inducing signaling proteins and presents an active area of structural and biochemical studies. In this work, we have probed mechanistic aspects of allosteric regulation of Hsp90 by client proteins via a detailed computational study of Hsp90 interactions with the tumor suppressor protein p53. Experimentally guided protein docking and molecular dynamics structural refinement have reconstructed the recognition-competent states of the Hsp90-p53 complexes that are consistent with the NMR studies. Protein structure network analysis has identified critical interacting networks and specific residues responsible for structural integrity and stability of the Hsp90-p53 complexes. Coarse-grained modeling was used to characterize the global dynamics of the regulatory complexes and map p53-induced changes in the conformational equilibrium of Hsp90. The variations in the functional dynamics profiles of the Hsp90-p53 complexes are consistent with the NMR studies and could explain differences in the functional role of the alternative binding sites. Despite the overall similarity of the collective movements and the same global interaction footprint, p53 binding at the C-terminal interaction site of Hsp90 may have a more significant impact on the chaperone dynamics, which is consistent with the stronger allosteric effect of these interactions revealed by the experimental studies. The results suggest that p53-induced modulation of the global dynamics and structurally stable interaction networks can target the regulatory hinge regions and facilitate stabilization of the closed Hsp90 dimer that underlies the fundamental stimulatory effect of the p53 client. PMID
Low sequence identity but high structural and functional conservation: The case of Hsp70/Hsp90 organizing protein (Hop/Sti1) of Leishmania braziliensis.
Batista, Fernanda A H; Seraphim, Thiago V; Santos, Clelton A; Gonzaga, Marisvanda R; Barbosa, Leandro R S; Ramos, Carlos H I; Borges, Júlio C
Parasites belonging to the genus Leishmania are subjected to extensive environmental changes during their life cycle; molecular chaperones/co-chaperones act as protagonists in this scenario to maintain cellular homeostasis. Hop/Sti1 is a co-chaperone that connects the Hsp90 and Hsp70 systems, modulating their ATPase activities and affecting the fate of client proteins because it facilitates their transfer from the Hsp70 to the Hsp90 chaperone. Hop/Sti1 is one of the most prevalent co-chaperones, highlighting its importance despite the relatively low sequence identity among orthologue proteins. This multi-domain protein comprises three tetratricopeptides domains (TPR1, TPR2A and TPR2B) and two Asp/Pro-rich domains. Given the importance of Hop/Sti1 for the chaperone system and for Leishmania protozoa viability, the Leishmania braziliensis Hop (LbHop) and a truncated mutant (LbHop(TPR2AB)) were characterized. Structurally, both proteins are α-helix-rich and highly elongated monomeric proteins. Functionally, they inhibited the ATPase activity of Leishmania braziliensis Hsp90 (LbHsp90) to a similar extent, and the thermodynamic parameters of their interactions with LbHsp90 were similar, indicating that TPR2A-TPR2B forms the functional center for the LbHop interaction with LbHsp90. These results highlight the structural and functional similarity of Hop/Sti1 proteins, despite their low sequence conservation compared to the Hsp70 and Hsp90 systems, which are phylogenetic highly conserved. PMID:27103305
Cytochemical identification of HSP110 during early mouse facial development.
Evrard, L; Vanmuylder, N; Dourov, N; Glineur, R; Louryan, S
Apoptotic cell death constitutes a common phenomenon observed during development. This process plays an important role in the regulation of cell populations and in early differentiation of embryonic organs. Several teratologic situations are considered as resulting in a dramatic increase of the apoptotic process. In mammalian cells, heat shock proteins (HSPs), expressed or increased in response to various stresses, act as molecular chaperones in physiological conditions. In order to determine specific histochemical markers of apoptotic cells in normal craniofacial development, we observed the expression of stress proteins (HSPs) 70, 86, and 110. The apoptotic pattern of mesectodermal cell death areas was confirmed using both nuclear staining (Feulgen) and specific labeling of DNA fragmentation (TUNEL). These areas are localized in the proximal parts of the first and second visceral arches. They are located in mesectodermal and ganglionic cells. Apoptotic mesectodermal populations strongly express HSP110, as shown by the cytochemical identification of HSP110 and by double staining HSP110-TUNEL, suggesting that this protein could be considered as a new marker for apoptotic embryonic cells, and could be used in further teratologic studies to better quantify induced cell death.
The HSP90 Inhibitor Ganetespib Radiosensitizes Human Lung Adenocarcinoma Cells
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Gomez-Casal, Roberto; Bhattacharya, Chitralekha [The University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213 (United States); Department of Medicine, The University of Pittsburgh, Pittsburgh, PA 15213 (United States); Epperly, Michael W. [The University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213 (United States); Department of Radiation Oncology, The University of Pittsburgh, Pittsburgh, PA 15213 (United States); Basse, Per H. [The University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213 (United States); Department of Immunology, The University of Pittsburgh, Pittsburgh, PA 15213 (United States); Wang, Hong [The University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213 (United States); Department of Biostatistics, The University of Pittsburgh, Pittsburgh, PA 15213 (United States); Wang, Xinhui [Harvard Medical School, Harvard University, 25 Shattuck Street, Boston, MA 02115 (United States); Proia, David A. [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States); Greenberger, Joel S. [The University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213 (United States); Department of Radiation Oncology, The University of Pittsburgh, Pittsburgh, PA 15213 (United States); Socinski, Mark A.; Levina, Vera, E-mail: firstname.lastname@example.com [The University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213 (United States); Department of Medicine, The University of Pittsburgh, Pittsburgh, PA 15213 (United States)
The molecular chaperone HSP90 is involved in stabilization and function of multiple client proteins, many of which represent important oncogenic drivers in NSCLC. Utilization of HSP90 inhibitors as radiosensitizing agents is a promising approach. The antitumor activity of ganetespib, HSP90 inhibitor, was evaluated in human lung adenocarcinoma (AC) cells for its ability to potentiate the effects of IR treatment in both in vitro and in vivo. The cytotoxic effects of ganetespib included; G2/M cell cycle arrest, inhibition of DNA repair, apoptosis induction, and promotion of senescence. All of these antitumor effects were both concentration- and time-dependent. Both pretreatment and post-radiation treatment with ganetespib at low nanomolar concentrations induced radiosensitization in lung AC cells in vitro. Ganetespib may impart radiosensitization through multiple mechanisms: such as down regulation of the PI3K/Akt pathway; diminished DNA repair capacity and promotion of cellular senescence. In vivo, ganetespib reduced growth of T2821 tumor xenografts in mice and sensitized tumors to IR. Tumor irradiation led to dramatic upregulation of β-catenin expression in tumor tissues, an effect that was mitigated in T2821 xenografts when ganetespib was combined with IR treatments. These data highlight the promise of combining ganetespib with IR therapies in the treatment of AC lung tumors.
草鱼hsp70和hsp90对温度急性变化的响应%Effect of rapid temperature change on expression of hsp70 and hsp90 in grass carp(Ctenopharyngodon idella)
Institute of Scientific and Technical Information of China (English)
周鑫; 董云伟; 王芳; 董双林
Grass carp ( Ctenopharyngodon idella) is one of the most important cultured fishes in China. During transportation in summer,massive mortality often occurs. As molecular chaperones,Hsps assist cells in their recovery from stress and promote cytoprotection. Limited reports described the expression of Hsps in grass carp at high temperatures, and the relationship between oxygen consumption, expression of heat shock protein and mortality needs to be investigated based on the oxygen- and capability- limited thermal tolerance theory (OCLTT) to further elucidate the thermal adaptation of this species to high temperature in view of integrated biology. In the present study,the expressions of hsp70 and hsp90 after rapid temperature increase were studied. Grass carps were acclimated at 20 t and then exposed to designated temperatures(20,22,24, 26,28,30,32,34 ℃) for 3 h heat shock. After 2 h-recovery at 20℃, liver, muscle and gill of tested fish were sampled and hsp70 and hsp90 were determined using semi-quantitive real-time PCR. Expression of hsps increased with temperature increase until 32℃ in muscle and gill, and then decreased at 34 ℃. In liver, expression of hsps kept increasing in all temperature treatments. These results indicated that hsp70 and hsp90 were sensitive to temperature increase in grass carp. Analyzed heat shock proteins data with previous results of oxygen consumption and lethal temperatures of grass carp, the physiological adaptations of grass carp could be explained by oxygen- and capability- limited thermal tolerance theory (OCLTT), which pointed out that the imbalance between oxygen demand and tissue oxygen supply ability was the primary factor which limited organisms' thermal tolerance and the ability of aerobic metabolism greatly limited the survival of organism beyond critical temperatures. With temperature increase, the maximum value of oxygen consumption in grass carp occurred at 28 ℃, and then the oxygen consumption decreased when
Molecular analysis of common wheat genes encoding three types of cytosolic heat shock protein 90 (Hsp90): functional involvement of cytosolic Hsp90s in the control of wheat seedling growth and disease resistance.
Wang, Guan-Feng; Wei, Xuening; Fan, Renchun; Zhou, Huanbin; Wang, Xianping; Yu, Chunmei; Dong, Lingli; Dong, Zhenying; Wang, Xiaojie; Kang, Zhensheng; Ling, Hongqing; Shen, Qian-Hua; Wang, Daowen; Zhang, Xiangqi
Heat shock protein 90 (Hsp90) molecular chaperones play important roles in plant growth and responses to environmental stimuli. However, little is known about the genes encoding Hsp90s in common wheat. Here, we report genetic and functional analysis of the genes specifying cytosolic Hsp90s in this species. Three groups of homoeologous genes (TaHsp90.1, TaHsp90.2 and TaHsp90.3), encoding three types of cytosolic Hsp90, were isolated. The loci containing TaHsp90.1, TaHsp90.2 and TaHsp90.3 genes were assigned to groups 2, 7 and 5 chromosomes, respectively. TaHsp90.1 genes exhibited higher transcript levels in the stamen than in the leaf, root and culm. TaHsp90.2 and TaHsp90.3 genes were more ubiquitously transcribed in the vegetative and reproductive organs examined. Decreasing the expression of TaHsp90.1 genes through virus-induced gene silencing (VIGS) caused pronounced inhibition of wheat seedling growth, whereas the suppression of TaHsp90.2 or TaHsp90.3 genes via VIGS compromised the hypersensitive resistance response of the wheat variety Suwon 11 to stripe rust fungus. Our work represents the first systematic determination of wheat genes encoding cytosolic Hsp90s, and provides useful evidence for the functional involvement of cytosolic Hsp90s in the control of seedling growth and disease resistance in common wheat.
Identification of an allosteric pocket on human hsp70 reveals a mode of inhibition of this therapeutically important protein.
Rodina, Anna; Patel, Pallav D; Kang, Yanlong; Patel, Yogita; Baaklini, Imad; Wong, Michael J H; Taldone, Tony; Yan, Pengrong; Yang, Chenghua; Maharaj, Ronnie; Gozman, Alexander; Patel, Maulik R; Patel, Hardik J; Chirico, William; Erdjument-Bromage, Hediye; Talele, Tanaji T; Young, Jason C; Chiosis, Gabriela
Hsp70s are important cancer chaperones that act upstream of Hsp90 and exhibit independent anti-apoptotic activities. To develop chemical tools for the study of human Hsp70, we developed a homology model that unveils a previously unknown allosteric site located in the nucleotide binding domain of Hsp70. Combining structure-based design and phenotypic testing, we discovered a previously unknown inhibitor of this site, YK5. In cancer cells, this compound is a potent and selective binder of the cytosolic but not the organellar human Hsp70s and has biological activity partly by interfering with the formation of active oncogenic Hsp70/Hsp90/client protein complexes. YK5 is a small molecule inhibitor rationally designed to interact with an allosteric pocket of Hsp70 and represents a previously unknown chemical tool to investigate cellular mechanisms associated with Hsp70. PMID:24239008
HSP70: a promising target for laryngeal carcinoma radiaotherapy by inhibiting cleavage and degradation of nucleolin
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Xu Jing
Full Text Available Abstract Previous studies have shown that heat shock proteins (HSPs were upregulated in various types of tumors and were associated with histological grade, recurrence and metastasis of malignant tumors. In this study, we investigated whether heat shock protein 70 kDa (HSP70 was associated with histological grade of laryngeal squamous cell carcinomas (LSCC. We also determine the role of HSP70 in LSCC radiation resistance using a laryngeal carcinoma xenograft model by antisense HSP70 RNA technique. Immunohistochemistry data showed that HSP70 was detected in 96% of LSCC tissues (48 out of 50. The expression level of HSP70 was significantly lower in early stage of LSCC than that in late stage (P = 0.015. Radiation treatment result showed that the volumes and weights of implantation tumors in the group injected with antisense HSP70 oligos were significantly reduced comparing to the group injected with random oligos(p
Cell-surface expression of Hsp70 on hematopoietic cancer cells after inhibition of HDAC activity
DEFF Research Database (Denmark)
Jensen, Helle; Andresen, Lars; Hansen, Karen Aagaard;
small HSPs). Hsp70 belongs to the HSP70 family and is expressed at low levels in normal non-stressed cells. Its expression is however induced by different cellular stresses, such as heat shock and oxidative stress. The function of Hsp70 depends on its cellular location: Intracellular it has...... normal ER/Golgi transport did not affect Hsp70 surface expression. Intracellular Calcium and the transcription factor Sp1, that has previously been shown to be important for the intracellular stress mediated by HDAC-inhibitors, were not involved in Hsp70 surface expression. We also found that HDAC...... cytoprotective and anti-apoptotic functions, whereas it exerts immunostimulatory functions extracellularly. Secreted Hsp70 is for example involved in cross-presentation of cancer-derived antigenic peptides, a function which is currently explored in immunotherapeutic approaches against cancer. Additionally...
Does Hsp60 Provide a Link between Mitochondrial Stress and Inflammation in Diabetes Mellitus?
The focus of this review is to summarise the known relationships between the expression of heat shock protein 60 (Hsp60) and its association with the pathogenesis of Type 1 and Type 2 diabetes mellitus. Hsp60 is a mitochondrial stress protein that is induced by mitochondrial impairment. It is known to be secreted from a number of cell types and circulating levels have been documented in both Types 1 and 2 diabetes mellitus patients. The biological significance of extracellular Hsp60, however, remains to be established. We will examine the links between Hsp60 and cellular anti- and proinflammatory processes and specifically address how Hsp60 appears to affect immune inflammation by at least two different mechanisms: as a ligand for innate immune receptors and as an antigen recognised by adaptive immune receptors. We will also look at the role of Hsp60 during immune cell activation in atherosclerosis, a significant risk factor during the pathogenesis of diabetes mellitus. PMID:27478851
Combining Bio-inspired Sensing with Bio-inspired Locomotion
DEFF Research Database (Denmark)
Shaikh, Danish; Hallam, John; Christensen-Dalsgaard, Jakob
In this paper we present a preliminary Braitenberg vehicle–like approach to combine bio-inspired audition with bio-inspired quadruped locomotion in simulation. Locomotion gaits of the salamander–like robot Salamandra robotica are modified by a lizard's peripheral auditory system model that modula......In this paper we present a preliminary Braitenberg vehicle–like approach to combine bio-inspired audition with bio-inspired quadruped locomotion in simulation. Locomotion gaits of the salamander–like robot Salamandra robotica are modified by a lizard's peripheral auditory system model...
BIOS Security Analysis and a Kind of Trusted BIOS
Zhou, Zhenliu; Xu, Rongsheng
The BIOS's security threats to computer system are analyzed and security requirements for firmware BIOS are summarized in this paper. Through discussion about TCG's trust transitivity, a new approach about CRTM implementation based on BIOS is developed. In this paper, we also put forward a new trusted BIOS architecture-UTBIOS which is built on Intel Framework for EFI/UEFI. The trustworthiness of UTBIOS is based on trusted hardware TPM. In UTBIOS, trust encapsulation and trust measurement are used to construct pre-OS trust chain. Performance of trust measurement is also analyzed in the end.
Members of the Hsp70 family of proteins in the cell wall of Saccharomyces cerevisiae.
López-Ribot, J L; Chaffin, W L
Western blot (immunoblot) analysis of cell wall and cytosolic extracts obtained from parental and ssa1 and ssa2 single- and double-mutant strains of Saccharomyces cerevisiae showed that the heat shock protein 70 (Hsp70) products of these genes, previously thought to be restricted to the cell interior, are also present in the cell wall. A cell wall location was further confirmed by indirect immunofluorescence with intact cells and biotinylation of extracellular Hsp70. Hsp70s have been implicat...
Expression and Localization of an Hsp70 Protein in the Microsporidian Encephalitozoon cuniculi
Jolly, Carrie E.; Leonard, Cory A.; J. Russell Hayman
Microsporidia spore surface proteins are an important, under investigated aspect of spore/host cell attachment and infection. For comparison analysis of surface proteins, we required an antibody control specific for an intracellular protein. An endoplasmic reticulum-associated heat shock protein 70 family member (Hsp70; ECU02_0100; "C1") was chosen for further analysis. DNA encoding the C1 hsp70 was amplified, cloned and used to heterologously express the C1 Hsp70 protein, and...
Interaction of the Hsp90 cochaperone cyclophilin 40 with Hsc70
Carrello, Amerigo; Allan, Rudi K.; Morgan, Sarah L.; Owen, Barbara A. L.; Mok, Danny; Ward, Bryan K.; Minchin, Rodney F; Toft, David O.; Ratajczak, Thomas
The high-affinity ligand-binding form of unactivated steroid receptors exists as a multicomponent complex that includes heat shock protein (Hsp)90; one of the immunophilins cyclophilin 40 (CyP40), FKBP51, or FKBP52; and an additional p23 protein component. Assembly of this heterocomplex is mediated by Hsp70 in association with accessory chaperones Hsp40, Hip, and Hop. A conserved structural element incorporating a tetratricopeptide repeat (TPR) domain mediates the interaction of the immunophi...
Chlamydia trachomatis infection and anti-Hsp60 immunity: the two sides of the coin.
Directory of Open Access Journals (Sweden)
Francesco Cappello
Full Text Available Chlamydia trachomatis (CT infection is one of the most common causes of reproductive tract diseases and infertility. CT-Hsp60 is synthesized during infection and is released in the bloodstream. As a consequence, immune cells will produce anti-CT-Hsp60 antibodies. Hsp60, a ubiquitous and evolutionarily conserved chaperonin, is normally sequestered inside the cell, particularly into mitochondria. However, upon cell stress, as well as during carcinogenesis, the chaperonin becomes exposed on the cell surface (sf-Hsp60 and/or is secreted from cells into the extracellular space and circulation. Reports in the literature on circulating Hsp and anti-Hsp antibodies are in many cases short on details about Hsp60 concentrations, and about the specificity spectra of the antibodies, their titers, and their true, direct, pathogenetic effects. Thus, more studies are still needed to obtain a definitive picture on these matters. Nevertheless, the information already available indicates that the concurrence of persistent CT infection and appearance of sf-Hsp60 can promote an autoimmune aggression towards stressed cells and the development of diseases such as autoimmune arthritis, multiple sclerosis, atherosclerosis, vasculitis, diabetes, and thyroiditis, among others. At the same time, immunocomplexes composed of anti-CT-Hsp60 antibodies and circulating Hsp60 (both CT and human may form deposits in several anatomical locations, e.g., at the glomerular basal membrane. The opposite side of the coin is that pre-tumor and tumor cells with sf-Hsp60 can be destroyed with participation of the anti-Hsp60 antibody, thus stopping cancer progression before it is even noticed by the patient or physician.
Role of Subunit Exchange and Electrostatic Interactions on the Chaperone Activity of Mycobacterium leprae HSP18
Nandi, Sandip Kumar; Panda, Alok Kumar; Chakraborty, Ayon; Ray, Sougata Sinha; Biswas, Ashis
Mycobacterium leprae HSP18, a major immunodominant antigen of M. leprae pathogen, is a small heat shock protein. Previously, we reported that HSP18 is a molecular chaperone that prevents aggregation of different chemically and thermally stressed client proteins and assists refolding of denatured enzyme at normal temperature. We also demonstrated that it can efficiently prevent the thermal killing of E. coli at higher temperature. However, molecular mechanism behind the chaperone function of HSP18 is still unclear. Therefore, we studied the structure and chaperone function of HSP18 at normal temperature (25°C) as well as at higher temperatures (31–43°C). Our study revealed that the chaperone function of HSP18 is enhanced significantly with increasing temperature. Far- and near-UV CD experiments suggested that its secondary and tertiary structure remain intact in this temperature range (25–43°C). Besides, temperature has no effect on the static oligomeric size of this protein. Subunit exchange study demonstrated that subunits of HSP18 exchange at 25°C with a rate constant of 0.018 min-1. Both rate of subunit exchange and chaperone activity of HSP18 is found to increase with rise in temperature. However, the surface hydrophobicity of HSP18 decreases markedly upon heating and has no correlation with its chaperone function in this temperature range. Furthermore, we observed that HSP18 exhibits diminished chaperone function in the presence of NaCl at 25°C. At elevated temperatures, weakening of interactions between HSP18 and stressed client proteins in the presence of NaCl results in greater reduction of its chaperone function. The oligomeric size, rate of subunit exchange and structural stability of HSP18 were also found to decrease when electrostatic interactions were weakened. These results clearly indicated that subunit exchange and electrostatic interactions play a major role in the chaperone function of HSP18. PMID:26098662
Recovery From Radiation-induced Bone Marrow Damage by HSP25 Through Tie2 Signaling
International Nuclear Information System (INIS)
Purpose: Whole-body radiation therapy can cause severe injury to the hematopoietic system, and therefore it is necessary to identify a novel strategy for overcoming this injury. Methods and Materials: Mice were irradiated with 4.5 Gy after heat shock protein 25 (HSP25) gene transfer using an adenoviral vector. Then, peripheral blood cell counts, histopathological analysis, and Western blotting on bone marrow (BM) cells were performed. The interaction of HSP25 with Tie2 was investigated with mouse OP9 and human BM-derived mesenchymal stem cells to determine the mechanism of HSP25 in the hematopoietic system. Results: HSP25 transfer increased BM regeneration and reduced apoptosis following whole-body exposure to ionizing radiation (IR). The decrease in Tie2 protein expression that followed irradiation of the BM was blocked by HSP25 transfer, and Tie2-positive cells were more abundant among the BM cells of HSP25-transferred mice, even after IR exposure. Following systemic RNA interference of Tie2 before IR, HSP25-mediated radioprotective effects were partially blocked in both mice and cell line systems. Stability of Tie2 was increased by HSP25, a response mediated by the interaction of HSP25 with Tie2. IR-induced tyrosine phosphorylation of Tie2 was augmented by HSP25 overexpression; downstream events in the Tie2 signaling pathway, including phosphorylation of AKT and EKR1/2, were also activated. Conclusions: HSP25 protects against radiation-induced BM damage by interacting with and stabilizing Tie2. This may be a novel strategy for HSP25-mediated radioprotection in BM.
Increased light intensity induces heat shock protein Hsp60 in coral species
Chow, Ari M.; Ferrier-Pagès, Christine; Khalouei, Sam; Reynaud, Stéphanie; Brown, Ian R.
The effect of increased light intensity and heat stress on heat shock protein Hsp60 was examined in two coral species using a branched coral and a laminar coral, selected for their different resistance to environmental perturbation. Transient Hsp60 induction was observed in the laminar coral following either light or thermal stress. Sustained induction was observed when these stresses were combined. The branched coral exhibited comparatively weak transient Hsp60 induction after heat stress an...
The role of HSP70 in mediating age-dependent mortality in sepsis
McConnell, Kevin W.; Fox, Amy C.; Clark, Andrew T.; Chang, Nai-Yuan Nicholas; Dominguez, Jessica A.; Farris, Alton B.; Buchman, Timothy G.; Hunt, Clayton R.; Coopersmith, Craig M.
Sepsis is primarily a disease of the aged, with increased incidence and mortality occurring in aged hosts. Heat shock protein (HSP) 70 plays an important role in both healthy aging and the stress response to injury. The purpose of this study was to determine the role of HSP70 in mediating mortality and the host inflammatory response in aged septic hosts. Sepsis was induced in both young (6–12week old) and aged (16–17 month old) HSP70−/− and wild type (WT) mice to determine if HSP70 modulated outcome in an age-dependent fashion. Young HSP70−/− and WT mice subjected to cecal ligation and puncture (CLP), Pseudomonas aeruginosa pneumonia or Streptococcus pneumoniae pneumonia had no differences in mortality, suggesting HSP70 does not mediate survival in young septic hosts. In contrast, mortality was higher in aged HSP70−/− mice than aged WT mice subjected to CLP (p=0.01), suggesting HSP70 mediates mortality in sepsis in an age-dependent fashion. Compared to WT mice, aged septic HSP70−/− mice had increased gut epithelial apoptosis and pulmonary inflammation. In addition, HSP70−/−mice had increased systemic levels of TNF-α, IL-6, IL-10 and IL-1β compared to WT mice. These data demonstrate that HSP70 is a key determinant of mortality in aged but not young hosts in sepsis. HSP70 may play a protective role in an age-dependent response to sepsis by preventing excessive gut apoptosis and both pulmonary and systemic inflammation. PMID:21296977
Hsp70 Knockdown by siRNA Decreased Collagen Production in Keloid Fibroblasts
Shin, Jung U; Lee, Won Jai; Tran, Thanh-Nga; Jung, Inhee; Lee, Ju Hee
Purpose There are currently no consistently effective treatments for the excessive collagen produced by keloid fibroblasts. Previously, we reported that heat shock protein 70 (Hsp70) is up-regulated in keloid fibroblasts and keloid tissue. We, therefore, investigated whether Hsp70 is related to excessive collagen production in keloid fibroblasts. Materials and Methods We inhibited Hsp70 in keloid fibroblasts by RNA interference and examined the resulting collagen expression. Thus, we selected...
Measurement of doses to aviator pilots using thermoluminescent dosemeters; Medicion de la dosis a pilotos aviadores usando dosimetros termoluminiscentes
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Azorin N, J.; Cruz C, D. [UAM-I, 09340 Mexico D.F. (Mexico); Rivera M, T. [IPN, ESIME Culhuacan (Mexico)]. e-mail: firstname.lastname@example.com
During the development of their work, the aviator pilots are exposed at high levels of natural radiation of bottom caused mainly by the cosmic radiation of galactic origin and lot. For such reason, the Metropolitan Autonomous University (UAM) and the Union Association of Aviator Pilots (ASPA), subscribed an agreement with the purpose of to measure the doses of ionizing radiation received by the aviator pilots of diverse air companies that man different types of airships and to determine if these doses surpass the one limit of 0.11 mSv/h settled down by the IAEA for the public in general; and if therefore, these workers should be considered as personnel occupationally exposed. In this work the obtained results when measuring the absorbed dose received by Mexican civil aviator pilots during the development of their work, using thermoluminescent dosemeters of LiF:Mg,Cu,P + Ptfe of national production are presented. The obtained results during the years of 2001 and 2002 show that the monthly doses received by the pilots surpass the one it limits established for the public in general, for what they should be considered as personnel occupationally exposed. (Author)
Assessment of effective radiation dose of an extremity CBCT, MSCT and conventional X ray for knee area using MOSFET dosemeters.
Koivisto, Juha; Kiljunen, Timo; Wolff, Jan; Kortesniemi, Mika
The objective of this study was to assess and compare the organ and effective doses in the knee area resulting from different commercially available multislice computed tomography devices (MSCT), one cone beam computed tomography device (CBCT) and one conventional X-ray radiography device using MOSFET dosemeters and an anthropomorphic RANDO knee phantom. Measurements of the MSCT devices resulted in effective doses ranging between 27 and 48 µSv. The CBCT measurements resulted in an effective dose of 12.6 µSv. The effective doses attained using the conventional radiography device were 1.8 µSv for lateral and 1.2 µSv for anterior-posterior projections. The effective dose resulting from conventional radiography was considerably lower than those recorded for the CBCT and MSCT devices. The MSCT effective dose results were two to four times higher than those measured on the CBCT device. This study demonstrates that CBCT can be regarded as a potential low-dose 3D imaging technique for knee examinations. PMID:23825221
Tl response of LiF: Mg, Cu, P + PTFE (Mexico) and GR200A (China) dosemeters; Respuesta Tl de dosimetros de LiF: Mg, Cu, P + PTFE (Mexico) y GR200A (China)
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Gonzalez M, P.R. [ININ, A.P. 18-1027, Mexico D.F. (Mexico); Azorin N, J.; Furetta, C. [UAM-I, 09340 Mexico D.F. (Mexico)
TLD-100 was the commercial dosemeter more known since some decades ago. This dosemeter was considered for many research groups as the reference material for developing new Tl materials for ionizing radiation dosimetry. Actually it seems that TLD-100 is going to be replaced by the Chinese material GR200A, as reference material due that this material in addition to be considered as a tissue equivalent material, is 30 to 35 times more sensitive that TLD- 100. Results of the study of the Tl response of LiF: Mg, Cu, P + Ptfe developed at ININ-Mexico, comparing them with those of GR200A are presented. These results showed that the sensitivity (s = Tl intensity/weight x dose) to gamma radiation of the LiF: Mg, Cu, P + Ptfe dosimeters was 4.34 meanwhile that of the commercial dosemeter was 3.41. Detection threshold of the dosemeters studied was 2.22 and 0.52 {mu}Gy respectively Repeatability after 10 cycles Irradiation-reading-annealing was {+-}1.39% and {+-}1.86% respectively. Both types of dosemeters presented a linear response as a function of gamma radiation in the range from 0.02 mGy and 100 Gy. (Author)
Destruction or potentiation of different prions catalyzed by similar Hsp104 remodeling activities
Shorter, James; Lindquist, Susan
Yeast prions are protein-based genetic elements that self-perpetuate changes in protein conformation and function. A protein-remodeling factor, Hsp104, controls the inheritance of several yeast prions, including those formed by Sup35 and Ure2. Perplexingly, deletion of Hsp104 eliminates Sup35 and Ure2 prions, whereas overexpression of Hsp104 purges cells of Sup35 prions, but not Ure2 prions. Here, we used pure components to dissect how Hsp104 regulates prion formation, growth, and division. F...
Tumor-specific Hsp70 plasma membrane localization is enabled by the glycosphingolipid Gb3.
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Mathias Gehrmann
Full Text Available BACKGROUND: Human tumors differ from normal tissues in their capacity to present Hsp70, the major stress-inducible member of the HSP70 family, on their plasma membrane. Membrane Hsp70 has been found to serve as a prognostic indicator of overall patient survival in leukemia, lower rectal and non small cell lung carcinomas. Why tumors, but not normal cells, present Hsp70 on their cell surface and the impact of membrane Hsp70 on cancer progression remains to be elucidated. METHODOLOGY/PRINCIPAL FINDINGS: Although Hsp70 has been reported to be associated with cholesterol rich microdomains (CRMs, the partner in the plasma membrane with which Hsp70 interacts has yet to be identified. Herein, global lipid profiling demonstrates that Hsp70 membrane-positive tumors differ from their membrane-negative counterparts by containing significantly higher amounts of globotriaoslyceramide (Gb3, but not of other lipids such as lactosylceramide (LacCer, dodecasaccharideceramide (DoCer, galactosylceramide (GalCer, ceramide (Cer, or the ganglioside GM1. Apart from germinal center B cells, normal tissues are Gb3 membrane-negative. Co-localization of Hsp70 and Gb3 was selectively determined in Gb3 membrane-positive tumor cells, and these cells were also shown to bind soluble Hsp70-FITC protein from outside in a concentration-dependent manner. Given that the latter interaction can be blocked by a Gb3-specific antibody, and that the depletion of globotriaosides from tumors reduces the amount of membrane-bound Hsp70, we propose that Gb3 is a binding partner for Hsp70. The in vitro finding that Hsp70 predominantly binds to artificial liposomes containing Gb3 (PC/SM/Chol/Gb3, 17/45/33/5 confirms that Gb3 is an interaction partner for Hsp70. CONCLUSIONS/SIGNIFICANCE: These data indicate that the presence of Gb3 enables anchorage of Hsp70 in the plasma membrane of tumors and thus they might explain tumor-specific membrane localization of Hsp70.
Chaperonopathies and chaperonotherapy. Hsp60 as therapeutic target in cancer: potential benefits and risks.
Cappello, Francesco; Angileri, Francesca; de Macario, Everly Conway; Macario, Alberto J L
In this minireview we focus on Hsp60 as a target for anticancer therapy. We discuss the new concepts of chaperonopathies and chaperonotherapy and present information on Hsp60 localization in the cell membrane of human tumor cells. We describe novel mechanisms for Hsp60 reaching the extracellular environment that involve membrane-associated stages, as well as data on anti-Hsp60 antibodies found in human sera, both in normal subjects and patients affected by autoimmune diseases. Finally, we discuss possible therapeutic applications of anti-Hsp60 antibodies in cancer treatment, evaluating also side effects on non-tumor cells. In conclusion, the way for investigating Hsp60-targeted anti-tumor therapy is open, at least for those tumors that express Hsp60 on its surface and/or secrete it outside the cell, as is the search for the molecular mechanisms involved in Hsp60 translocation from cytosol to cell membrane: elucidation of this mechanism will greatly facilitate the optimization of chaperonotherapy centered on Hsp60 with anti-tumor efficacy and minimal side effects.
Hsp70 chaperone systems: diversity of cellular functions and mechanism of action.
Mayer, M P; Bukau, B
Hsp70 chaperone systems play an essential role in the life cycle of many proteins not only in an hostile environment but also under normal growth conditions. In the course of evolution the diversification of functions was accompanied by an amplification of components of the Hsp70 system. Here strategies are reviewed how different Hsp70 systems work independently or cooperate with each other in a functional network to perform their housekeeping tasks even under stress conditions. We further discuss how co-chaperones which act as targeting factors regulate the cycle of substrate binding and release upon which the Hsp70 chaperone activity depends.
Induction of hsp70 by the herbicide oxyfluorfen (Goal) in the Egyptian Nile fish, Oreochromis niloticus.
Hassanein, H M; Banhawy, M A; Soliman, F M; Abdel-Rehim, S A; Müller, W E; Schröder, H C
This paper deals with the expression of the biomarker hsp70 in the liver and kidney of the freshwater fish Oreochromis niloticus following exposure to the herbicide oxyfluorfen (Goal). Fishes were exposed to three concentrations, the 96-h LC50 (3 mg/L), the 96-h (1/2)LC50 (1.5 mg/L), and the 96-h (1/4)LC50 (0.75 mg/L) of oxyfluorfen for 6, 15, and 24 days, respectively, and samples were taken at three different time periods for each concentration. The livers responded to the herbicide by an induction of the expression of both the constitutive (hsp75; Mr 75 kDa) and the inducible (hsp73; Mr 73 kDa) hsp70 proteins. In kidney, the herbicide induced a time-dependent increase in the expression of the constitutive hsp70 (hsp75) as well, but the inducible hsp70 (hsp73) required much longer incubation periods to reach maximal levels (15 and 24 days). Our results suggest that expression of hsp70 in fish is a sensitive indicator of cellular responses to herbicide exposure in the aquatic environment. PMID:10341045
Potentiated Hsp104 variants suppress toxicity of diverse neurodegenerative disease-linked proteins
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Meredith E. Jackrel
Full Text Available Protein misfolding is implicated in numerous lethal neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS and Parkinson disease (PD. There are no therapies that reverse these protein-misfolding events. We aim to apply Hsp104, a hexameric AAA+ protein from yeast, to target misfolded conformers for reactivation. Hsp104 solubilizes disordered aggregates and amyloid, but has limited activity against human neurodegenerative disease proteins. Thus, we have previously engineered potentiated Hsp104 variants that suppress aggregation, proteotoxicity and restore proper protein localization of ALS and PD proteins in Saccharomyces cerevisiae, and mitigate neurodegeneration in an animal PD model. Here, we establish that potentiated Hsp104 variants possess broad substrate specificity and, in yeast, suppress toxicity and aggregation induced by wild-type TDP-43, FUS and α-synuclein, as well as missense mutant versions of these proteins that cause neurodegenerative disease. Potentiated Hsp104 variants also rescue toxicity and aggregation of TAF15 but not EWSR1, two RNA-binding proteins with a prion-like domain that are connected with the development of ALS and frontotemporal dementia. Thus, potentiated Hsp104 variants are not entirely non-specific. Indeed, they do not unfold just any natively folded protein. Rather, potentiated Hsp104 variants are finely tuned to unfold proteins bearing short unstructured tracts that are not recognized by wild-type Hsp104. Our studies establish the broad utility of potentiated Hsp104 variants.
Proteomics shows Hsp70 does not bind peptide sequences indiscriminately in vivo
International Nuclear Information System (INIS)
Heat shock protein 70 (Hsp70) binds peptide and has several functions that include protein folding, protein trafficking, and involvement with immune function. However, endogenous Hsp70-binding peptides had not previously been identified. Therefore, we eluted and identified several hundred endogenously bound peptides from Hsp70 using liquid chromatography ion trap mass spectrophotometry (LC-ITMS). Our work shows that the peptides are capable of binding Hsp70 as previously described. They are generally 8-26 amino acids in length and correspond to specific regions of many proteins. Through computationally assisted analysis of peptides eluted from Hsp70 we determined variable amino acid sequences, including a 5 amino acid core sequence that Hsp70 favorably binds. We also developed a computer algorithm that predicts Hsp70 binding within proteins. This work helps to define what peptides are bound by Hsp70 in vivo and suggests that Hsp70 facilitates peptide selection by aiding a funneling mechanism that is flexible but allows only a limited number of peptides to be processed
Cord blood CD4+ T cells respond to self heat shock protein 60 (HSP60.
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Joost A Aalberse
Full Text Available BACKGROUND: To prevent harmful autoimmunity most immune responses to self proteins are controlled by central and peripheral tolerance. T cells specific for a limited set of self-proteins such as human heat shock protein 60 (HSP60 may contribute to peripheral tolerance. It is not known whether HSP60-specific T cells are present at birth and thus may play a role in neonatal tolerance. We studied whether self-HSP60 reactive T cells are present in cord blood, and if so, what phenotype these cells have. METHODOLOGY/PRINCIPAL FINDINGS: Cord blood mononuclear cells (CBMC of healthy, full term neonates (n = 21, were cultured with HSP60 and Tetanus Toxoid (TT to study antigen specific proliferation, cytokine secretion and up-regulation of surface markers. The functional capacity of HSP60-induced T cells was determined with in vitro suppression assays. Stimulation of CBMC with HSP60 led to CD4(+ T cell proliferation and the production of various cytokines, most notably IL-10, Interferon-gamma, and IL-6. HSP60-induced T cells expressed FOXP3 and suppressed effector T cell responses in vitro. CONCLUSION: Self-reactive HSP60 specific T cells are already present at birth. Upon stimulation with self-HSP60 these cells proliferate, produce cytokines and express FOXP3. These cells function as suppressor cells in vitro and thus they may be involved in the regulation of neonatal immune responses.
Investigation of HSP60 gene expression in mRNA level in heart at dilated cardiomyopathy
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Riabenko D. V.
Full Text Available The expression of HSP60 in the mRNA level in human hearts at the end-stage of dilated cardiomyopathy (DCM as well as in the hearts of mice with disease model similar to human DCM was investigated. We observed a significant increase in the Hsp60 mRNA level at the beginning of the disease and decrease to a normal level at the end stage. As the Hsp60 level was increased during the disease up to the end stage we can presume some changes in the regulation of Hsp60 synthesis or its degradation at DCM progression
两种粉虱Hsp60基因的克隆与表达%Cloning and Expression of Hsp60 Gene in Two Whitefly
Institute of Scientific and Technical Information of China (English)
郭莉莉; 肖林云; 余昊; 王运兵
以近缘昆虫Hsp60基因保守区域设计兼并引物,PCR扩增烟粉虱(Bemisiatabaci)地中海(MED)隐种与温室白粉虱(Trialeurodes vaporariorum)Hsp60基因cDNA,并检测了Hsp60基因受温度影响的表达情况.结果表明,烟粉虱MED隐种Hsp60基因cDNA的开放性阅读框长1 821bp,编码607个氨基酸;温室白粉虱Hsp60基因cDNA的开放性阅读框长1 788 bp,编码596个氨基酸,Hsp60基因在昆虫纲低级阶元水平和高级阶元水平系统进化上能得到一个较理想结果.温室白粉虱Hsp60基因表达量受温度影响显著(P<0.05),而烟粉虱MED隐种则不显著(P>0.05).
Clinical application of bio ceramics
Anu, Sharma; Gayatri, Sharma
Ceramics are the inorganic crystalline material. These are used in various field such as biomedical, electrical, electronics, aerospace, automotive and optical etc. Bio ceramics are the one of the most active areas of research. Bio ceramics are the ceramics which are biocompatible. The unique properties of bio ceramics make them an attractive option for medical applications and offer some potential advantages over other materials. During the past three decades, a number of major advances have been made in the field of bio ceramics. This review focuses on the use of these materials in variety of clinical scenarios.
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Francisco Javier León Correa
Full Text Available Desde el inicio de la publicación de la revista Cuadernos de Bioética, hemos podido comprobar una evolución importante en el desarrollo de esta disciplina, tanto en España como en Latinoamérica, que son los ámbitos donde muy especialmente se difunde. Trataré de señalar los aspectos que considero de mayor interés en los inicios y desarrollo de esta nueva disciplina, para poder entender mejor los retos actuales que enfrenta y cuáles son las líneas que ha seguido la revista en esta andadura inicial, y que deberá seguir para responder a los retos de los próximos años. Es un reto la realidad que vivimos en nuestros países, con la aprobación de leyes impuestas desde los poderes públicos con muy poca o ninguna discusión social que se parezca de lejos al diálogo tolerante racional que propugna la Bioética; con las reformas aceleradas e indecisas de los sistemas de salud; con el cambio del rol del médico y de la relación médico-paciente desde un paternalismo aún presente a un modelo participativo o contractual sin defi nir claramente; con importantes desigualdades en el acceso a la atención de salud dentro de cada propio país, pero a la vez con un creciente reconocimiento de los derechos de los pacientes y de su necesaria participación para mejorar la calidad de la asistencia clínica. Tiene especial importancia valorar cuáles han sido los instrumentos del éxito y de la difusión de la Bioética clínica, y cuáles pueden ser las nuevas propuestas para el desarrollo de la Bioética como una disciplina de debate ético social y político, ligada a las exigencias éticas de la justicia y el desarrollo social. Hemos de ver cuál ha sido el aporte en estos quince años de la revista Cuadernos de Bioética, con la colaboración de cientos de autores de diversos países, en que se ha mantenido fi el a la propuesta de los que la iniciamos en Santiago de Compostela en el año 1990: construir un buen aporte al debate actual de Bio
Protective Role of Hsp27 Protein Against Gamma Radiation-Induced Apoptosis and Radiosensitization Effects of Hsp27 Gene Silencing in Different Human Tumor Cells
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Purpose: The ability of heat shock protein 27 (Hsp27) to protect cells from stressful stimuli and its increased levels in tumors resistant to anticancer therapeutics suggest that it may represent a target for sensitization to radiotherapy. In this study, we investigate the protective role of Hsp27 against radiation-induced apoptosis and the effect of its attenuation in highly expressing radioresistant cancer cell lines. Methods and Materials: We examined clonogenic death and the kinetics of apoptotic events in different tumor cell lines overexpressing or underexpressing Hsp27 protein irradiated with photons. The radiosensitive Jurkat cell line, which does not express Hsp27 constitutively or in response to γ-rays, was stably transfected with Hsp27 complementary DNA. Attenuation of Hsp27 expression was accomplished by antisense or RNAi (interfering RNA) strategies in SQ20B head-and-neck squamous carcinoma, PC3 prostate cancer, and U87 glioblastoma radioresistant cells. Results: We measured concentration-dependent protection against the cytotoxic effects of radiation in Jurkat-Hsp27 cells, which led to a 50% decrease in apoptotic cells at 48 hours in the highest expressing cells. Underlying mechanisms leading to radiation resistance involved a significant increase in glutathione levels associated with detoxification of reactive oxygen species, a delay in mitochondrial collapse, and caspase activation. Conversely, attenuation of Hsp27 in SQ20B cells, characterized by their resistance to apoptosis, sensitizes cells to irradiation. This was emphasized by increased apoptosis, decreased glutathione basal level, and clonogenic cell death. Sensitization to irradiation was confirmed in PC3 and U87 radioresistant cells. Conclusion: Hsp27 gene therapy offers a potential adjuvant to radiation-based therapy of resistant tumors
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Trewhella, J. (Jill)
Bioforensics presents significant technical challenges. Determining if an outbreak is natural or not, and then providing evidence to trace an outbreak to its origin is very complex. Los Alamos scientists pioneered research and development that has generated leading edge strain identification methods based on sequence data. Molecular characterization of environmental background samples enable development of highly specific pathogen signatures. Economic impacts of not knowing the relationships at the molecular level Many different kinds of data are needed for DNA-based bio-forensics.
A network-based approach for predicting Hsp27 knock-out targets in mouse skeletal muscles
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Joëlle Henry-Berger
Full Text Available Thanks to genomics, we have previously identified markers of beef tenderness, and computed a bioinformatic analysis that enabled us to build an interactome in which we found Hsp27 at a crucial node. Here, we have used a network-based approach for understanding the contribution of Hsp27 to tenderness through the prediction of its interactors related to tenderness. We have revealed the direct interactors of Hsp27. The predicted partners of Hsp27 included proteins involved in different functions, e.g. members of Hsp families (Hsp20, Cryab, Hsp70a1a, and Hsp90aa1, regulators of apoptosis (Fas, Chuk, and caspase-3, translation factors (Eif4E, and Eif4G1, cytoskeletal proteins (Desmin and antioxidants (Sod1. The abundances of 15 proteins were quantified by Western blotting in two muscles of HspB1-null mice and their controls. We observed changes in the amount of most of the Hsp27 predicted targets in mice devoid of Hsp27 mainly in the most oxidative muscle. Our study demonstrates the functional links between Hsp27 and its predicted targets. It suggests that Hsp status, apoptotic processes and protection against oxidative stress are crucial for post-mortem muscle metabolism, subsequent proteolysis, and therefore for beef tenderness.
Diversity of cytosolic HSP70 Heat Shock Protein from decapods and their phylogenetic placement within Arthropoda.
Baringou, Stephane; Rouault, Jacques-Deric; Koken, Marcel; Hardivillier, Yann; Hurtado, Luis; Leignel, Vincent
The 70kDa heat shock proteins (HSP70) are considered the most conserved members of the HSP family. These proteins are primordial to the cell, because of their implications in many cellular pathways (e. g., development, immunity) and also because they minimize the effects of multiple stresses (e. g., temperature, pollutants, salinity, radiations). In the cytosol, two ubiquitous HSP70s with either a constitutive (HSC70) or an inducible (HSP70) expression pattern are found in all metazoan species, encoded by 5 or 6 genes (Drosophila melanogaster or yeast and human respectively). The cytosolic HSP70 protein family is considered a major actor in environmental adaptation, and widely used in ecology as an important biomarker of environmental stress. Nevertheless, the diversity of cytosolic HSP70 remains unclear amongst the Athropoda phylum, especially within decapods. Using 122 new and 311 available sequences, we carried out analyses of the overall cytosolic HSP70 diversity in arthropods (with a focus on decapods) and inferred molecular phylogenies. Overall structural and phylogenetic analyses showed a surprisingly high diversity in cytosolic HSP70 and revealed the existence of several unrecognised groups. All crustacean HSP70 sequences present signature motifs and molecular weights characteristic of non-organellar HSP70, with multiple specific substitutions in the protein sequence. The cytosolic HSP70 family in arthropods appears to be constituted of at least three distinct groups (annotated as A, B and C), which comprise several subdivisions, including both constitutive and inducible forms. Group A is constituted by several classes of Arthropods, while group B and C seem to be specific to Malacostraca and Hexapoda/Chelicerata, respectively. The HSP70 organization appeared much more complex than previously suggested, and far beyond a simple differentiation according to their expression pattern (HSC70 versus HSP70). This study proposes a new classification of cytosolic
Hsp90 as a "Chaperone" of the Epigenome: Insights and Opportunities for Cancer Therapy.
Isaacs, Jennifer S
The cellular functions of Hsp90 have historically been attributed to its ability to chaperone client proteins involved in signal transduction. Although numerous stimuli and the signaling cascades they activate contribute to cancer progression, many of these pathways ultimately require transcriptional effectors to elicit tumor-promoting effects. Despite this obvious connection, the majority of studies evaluating Hsp90 function in malignancy have focused upon its regulation of cytosolic client proteins, and particularly members of receptor and/or kinase families. However, in recent years, Hsp90 has emerged as a pivotal orchestrator of nuclear events. Discovery of an expanding repertoire of Hsp90 clients has illuminated a vital role for Hsp90 in overseeing nuclear events and influencing gene transcription. Hence, this chapter will cast a spotlight upon several regulatory themes involving Hsp90-dependent nuclear functions. Highlighted topics include a summary of chaperone-dependent regulation of key transcription factors (TFs) and epigenetic effectors in malignancy, as well as a discussion of how the complex interplay among a subset of these TFs and epigenetic regulators may generate feed-forward loops that further support cancer progression. This chapter will also highlight less recognized indirect mechanisms whereby Hsp90-supported signaling may impinge upon epigenetic regulation. Finally, the relevance of these nuclear events is discussed within the framework of Hsp90's capacity to enable phenotypic variation and drug resistance. These newly acquired insights expanding our understanding of Hsp90 function support the collective notion that nuclear clients are major beneficiaries of Hsp90 action, and their impairment is likely responsible for many of the anticancer effects elicited by Hsp90-targeted approaches.
Institute of Scientific and Technical Information of China (English)
冯作化; 黄波; 张桂梅; 李东; 王洪涛
Objective: To investigate the feasibility of decreasing the dosage of tumor antigen peptides by dendritic cell (DC)-presenting and the characteristics of modification of DC by heat shock protein (Hsp70) and antigen peptides. Methods: Peptides were bound to Hsp70 and used to modify DC in vitro. The metabolism of the modified DC and the cytokines secreted by the modified DC were determined. The activation of lymphocytes by the modified DC and Hsp70-H22 peptides was tested. The cytotoxicity of the activated lymphocytes to H22 tumor cells was analyzed. The inhibitory effect of tumor in mice by the injection of DC and Hsp70-H22 peptides was tested. Results: 0.15μg of H22 peptides bound with Hsp70 could make 2×105 DC mature. 4×103 matured DC could activate 2×106 lymphocytes. The same amount of lymphocytes could be activated to produce similar cytotoxicity to tumor cells by either DC modified by 0.003μg of peptides bound with Hsp70 or by direct stimulation with 0.15μg of peptides bound with Hsp70. The dosage of peptides could be reduced by about 50 folds if the modified DC was used for injection instead of Hsp70-peptides. Peptides from normal hepatocytes, bound with Hsp70, could not make DC mature, nor activate lymphocytes through DC. Conclusion: The dosage of Hsp70-H22 peptides can be reduced significantly by DC-presenting to activate lymphocytes. Peptides from normal cells could not activate lymphocytes by either Hsp70-presenting or DC-presenting and they have little chance to induce autoimmunity.
Decreased Hsp90 expression in infiltrative lobular carcinoma: an immunohistochemical study
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Zagouri Flora
Full Text Available Abstract Background Elevated Hsp90 expression has been documented in breast ductal carcinomas, whereas decreased Hsp90 expression has been reported in precursor lobular lesions. This study aims to assess Hsp90 expression in infiltrative lobular carcinomas of the breast. Methods Tissue specimens were taken from 32 patients with infiltrative lobular carcinoma. Immunohistochemical assessment of Hsp90 was performed both in the lesion and the adjacent normal breast ducts and lobules; the latter serving as control. Concerning Hsp90 assessment: i the percentage of positive cells and ii the intensity were separately analyzed. Subsequently, the Allred score was adopted and calculated. The intensity was treated as an ordinal variable-score (0: negative, low: 1, moderate: 2, high: 3. Statistical analysis followed. Results All infiltrative lobular carcinoma foci mainly presented with a positive cytoplasmic immunoreaction for Hsp90. Compared to the adjacent normal ducts and lobules, infiltrative lobular carcinoma exhibited a statistically significant decrease in Hsp90 expression, both in terms of Hsp90 positive cells (% and Allred score (74.2 ± 11.2 vs. 59.1 ± 14.2 p = 0.0001; 7.00 ± 0.95 vs. 6.22 ± 1.01, p = 0.007, Wilcoxon matched-pairs signed-ranks test. Concerning the intensity of Hsp90 immunostaining only a marginal decrease was noted (2.16 ± 0.68 vs. 1.84 ± 0.63, p = 0.087, Wilcoxon matched-pairs signed-ranks test. Conclusion ILC lesions seem to exhibit decreased Hsp90 expression, a finding contrary to what might have been expected, given that high Hsp90 expression is a trait of invasive ductal carcinomas.
Cytosolic HSP90 Cochaperones HOP and FKBP Interact with Freshly Synthesized Chloroplast Preproteins of Arabidopsis
Institute of Scientific and Technical Information of China (English)
Christine Fellerer; Regina Schweiger; Katharina Sch(o)ngruber; Jürgen Soll; Serena Schwenkert
Most chloroplast and mitochondrial proteins are synthesized in the cytosol of the plant cell and have to be imported into the organelles post-translationally.Molecular chaperones play an important role in preventing protein aggregation of freshly translated preproteins and assist in maintaining the preproteins in an import competent state.Preproteins can associate with HSPT0,HSP90,and 14-3-3 proteins in the cytosol.In this study,we analyzed a large set of wheat germ-translated chloroplast preproteins with respect to their chaperone binding.Our results demonstrate that the formation of distinct 14-3-3 or HSP90 containing preprotein complexes is a common feature in post-translational protein transport in addition to preproteins that seem to interact solely with HSP70.We were able to identify a diverse and extensive class of preproteins as HSP90 substrates,thus providing a tool for the investigation of HSP90 client protein association.The analyses of chimeric HSP90 and 14-3-3 binding preproteins with exchanged transit peptides indicate an involvement of both the transit peptide and the mature part of the proteins,in HSP90 binding.We identified two partner components of the HSP90 cycle,which were present in the preprotein containing high-molecular-weight complexes,the HSP70/HSP90 organizing protein HOP,as well as the immunophilin FKBP73.The results establish chloroplast preproteins as a general class of HSP90 client proteins in plants using HOP and FKBP as novel cochaperones.
Use of an enzyme-linked immunosorbent assay (Elisa) for the determination of HSP 70
International Nuclear Information System (INIS)
It has been suggested that HSP 70 is a good indicator to quantify thermotolerance. The authors developed an enzyme-linked immunosorbent assay (Elisa) for measuring the total amount of HSP 70 in mammalian cells. Microtitration plates were incubated with various concentrations of cell lysate in PBS. Milk proteins were used to block non-specific protein binding sites in the wells. Monoclonal antibody against purified HSP 70 raised in a mouse was added, followed by peroxidase conjugated goat-anti-mouse antibody. After washing, the bound peroxidase activity was measured colorimetrically to calculate the original amount of HSP 70 antigen. Kinetic studies indicate that the linear range of the assay corresponds to the amount of HSP 70 from 103-104 HA-1 cells (0.1-2.0 μg cytosolic proteins in each well). Elisa is a highly sensitive method for quantifying HSP 70 and can be easily used to measure the total amount of HSP 70 instead of the synthesis rate of HSP 70 by pulse radiolabeling. The authors are currently developing the sensitive Elisa system for measurement of thermotolerance in human tumors. A comparison of measurement of HSP 70 by pulse labeling the cells with 35S-methionine and by Elisa has been done in HA-1 cells. HA-1 cells were exposed to 450C, 10 min, then incubated at 370C for 0-24 h. These results show that the rate of HSP synthesis increased several fold, although the total amount of HSP 70 is increased less than 2 fold during thermotolerance induction. These results are consistent with data in the literature obtained by other techniques
Heating of tissues in vivo by pulsed focused ultrasound to stimulate enhanced HSP expression
Kujawska, Tamara; Wójcik, Janusz; Nowicki, Andrzej
The main aim of this work was numerical modeling of temperature fields induced in soft tissues in vivo by pulsed focused ultrasound during neurodegenerative disease treatment and experimental verification of the proposed model for a rat liver. The new therapeutic approach to neurodegenerative diseases consists of stimulation of enhanced expression of the Heat Shock Proteins (HSP) which are responsible for immunity of cells to stress. During therapy the temperature rise in tissues in vivo should not exceed 6 °C above level of the thermal norm (37 °C). First, the 3D acoustic pressure field, and the rate of heat production per unit volume due to that field, were calculated using our 3D numerical solver capable of predicting nonlinear propagation of pulsed high intensity waves generated from circular focused acoustic sources in multilayer configuration of attenuating media. The two-layer configuration of media (water—rat liver) assumed in calculations fairly well approximated both the real anatomic dimensions of rat liver and the geometric scheme of our experimental set-up. A numerical solution of the Pennes bio-heat transfer equation which accounted for the effects of heat diffusion, blood perfusion and metabolism rates, was employed to calculate the temperature fields induced in the rat liver by the ultrasonic beam. The numerical simulation results were verified experimentally using a thermocouple inserted in the liver of a rat under anesthesia at the beam focus. The quantitative analysis of the obtained results enabled estimation of the effects of several acoustic and thermal parameters of the rat liver in vivo on the temperature rise, as well as determination of exposure time for ultrasonic beams with varied acoustic power generated by a 2-MHz circular transducer of 15-mm diameter and 25-mm focal length, in order to avoid the tissue overheating that leads to cells necrosis, which would be unacceptable in neurodegenerative disease treatment.
Quantitative patterns of Hsps in tubular adenoma compared with normal and tumor tissues reveal the value of Hsp10 and Hsp60 in early diagnosis of large bowel cancer.
Rappa, Francesca; Pitruzzella, Alessandro; Marino Gammazza, Antonella; Barone, Rosario; Mocciaro, Emanuele; Tomasello, Giovanni; Carini, Francesco; Farina, Felicia; Zummo, Giovanni; Conway de Macario, Everly; Macario, Alberto Jl; Cappello, Francesco
Large bowel carcinogenesis involves accumulation of genetic alterations leading to transformation of normal mucosa into dysplasia and, lastly, adenocarcinoma. It is pertinent to elucidate the molecular changes occurring in the pre-neoplastic lesions to facilitate early diagnosis and treatment. Heat shock proteins (Hsps), many of which are molecular chaperones, are implicated in carcinogenesis, and their variations with tumor progression encourage their study as biomarkers. There are many reports on Hsps and cancer but none to our knowledge on their systematic quantification in pre-neoplastic lesions of the large bowel. We performed immunohistochemical determinations of Hsp10, Hsp60, Hsp70, and Hsp90 in biopsies of large bowel tubular adenomas with moderate grade of dysplasia and compared to normal mucosa and adenocarcinoma with a moderate grade of differentiation (G2). A significant elevation of Hsp10 and Hsp60 only, i.e., in the absence of elevation of Hsp70 or Hsp90, in both epithelium and lamina propria was found in tubular adenoma by comparison with normal mucosa. In contrast, adenocarcinoma was characterized by the highest levels of Hsp10 and Hsp60 in epithelium and lamina propria, accompanied by the highest levels of Hsp70 only in epithelium and of Hsp90 only in lamina propria, by comparison with normal and tubular adenoma counterparts. Hsp10 and Hsp60 are promising biomarkers for early diagnosis of tubular adenoma and for its differentiation from more advanced malignant lesions. Hsp10 and Hsp60 may be implicated in carcinogenesis from its very early steps and, thus, are potentially convenient targets for therapy.
Fitzpatrick, Roberta Bronson
BioOne is a Web-based aggregation of full-text, high-impact bioscience research journals. Most of its titles are published by small societies or non-commercial publishers and have not been previously available in electronic format. This column describes the BioOne database and gives some basic information about the best ways to search its content.
Bio-threat microparticle simulants
Farquar, George Roy; Leif, Roald N
A bio-threat simulant that includes a carrier and DNA encapsulated in the carrier. Also a method of making a simulant including the steps of providing a carrier and encapsulating DNA in the carrier to produce the bio-threat simulant.
Targeting Plasmodium falciparum Hsp90: Towards Reversing Antimalarial Resistance
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Dea Shahinas
Full Text Available Malaria continues to exact a great human toll in tropical settings. Antimalarial resistance is rife and the parasite inexorably develops mechanisms to outwit our best drugs, including the now first-line choice, artesunate. Novel strategies to circumvent resistance are needed. Here we detail drug development focusing on heat shock protein 90 and its central role as a chaperone. A growing body of evidence supports the role for Hsp90 inhibitors as adjunctive drugs able to restore susceptibility to traditionally efficacious compounds like chloroquine.
Analysis of Hsp90 cochaperone interactions reveals a novel mechanism for TPR protein recognition.
Chadli, Ahmed; Bruinsma, Elizabeth S; Stensgard, Bridget; Toft, David
The chaperone Hsp90 is required for the appropriate regulation of numerous key signaling molecules, including the progesterone receptor (PR). Many important cochaperones bind Hsp90 through their tetratricopeptide repeat (TPR) domains. Two such proteins, GCUNC45 and FKBP52, assist PR chaperoning and are thought to interact sequentially with PR-Hsp90 complexes. TPR proteins bind to the C-terminal MEEVD sequence of Hsp90, but GCUNC45 has been shown also to bind to a novel site near the N-terminus. We now show that FKBP52 is also able to bind to this site, and that these two cochaperones act competitively, through Hsp90, to modulate PR activity. The N-terminal site involves noncontiguous amino acids within or near the ATP binding pocket of Hsp90. TPR interactions at this site are thus strongly regulated by nucleotide binding and Hsp90 conformation. We propose an expanded model for client chaperoning in which the coordinated use of TPR recognition sites at both N- and C-terminal ends of Hsp90 enhances its ability to coordinate interactions with multiple TPR partners.
Phosphorylation and oligomerization states of native pig brain HSP90 studied by mass spectrometry
DEFF Research Database (Denmark)
Garnier, C.; Lafitte, D.; Jorgensen, T.J.;
HSP90 is one of the most abundant proteins in the cytosol of eukaryotic cells. HSP90 forms transient or stable complexes with several key proteins involved in signal transduction including protooncogenic protein kinases and nuclear receptors, it interacts with cellular structural elements...
Identification and characterization of cytosolic Hansenula polymorpha proteins belonging to the Hsp70 protein family
Titorenko, Vladimir I.; Evers, Melchior E.; Diesel, Andre; Samyn, Bart; Beeumen, Josef van; Roggenkamp, Rainer; Kiel, Jan A.K.W.; Klei, Ida J. van der; Veenhuis, Marten
We have isolated two members of the Hsp70 protein family from the yeast Hansenula polymorpha using affinity chromatography. Both proteins were located in the cytoplasm. One of these, designated Hsp72, was inducible in nature (e.g. by heat shock). The second protein (designated Hsc74) was constitutiv
Hsp60, a novel target for antitumor therapy: structure-function features and prospective drugs design.
Pace, Andrea; Barone, Giampaolo; Lauria, Antonino; Martorana, Annamaria; Piccionello, Antonio Palumbo; Pierro, Paola; Terenzi, Alessio; Almerico, Anna Maria; Buscemi, Silvestre; Campanella, Claudia; Angileri, Francesca; Carini, Francesco; Zummo, Giovanni; de Macario, Everly Conway; Cappello, Francesco; Macario, Alberto J L
Heat shock protein 60 kDa (Hsp60) is a chaperone classically believed to be involved in assisting the correct folding of other mitochondrial proteins. Hsp60 also plays a role in cytoprotection against cell stressors, displaying for example, antiapoptotic potential. Despite the plethora of studies devoted to the mechanism of Hsp60's function, especially in prokaryotes, fundamental issues still remain unexplored, including the definition of its role in cancer. Key questions still unanswered pertain to the differences in structure-function features that might exist between the well-studied prokaryotic GroEL and the largely unexplored eukaryotic Hsp60 proteins. In this article we discuss these differences in sequence, structure, and roles of Hsp60, focusing on the human ortholog with the view of devising compounds to block its ability to favour tumor-cell growth and survival. Compounds currently known to directly or indirectly affect Hsp60 functions, such as protein folding, HIF-1α accumulation, or Hsp60-induced cell proliferation, are discussed along with strategies that might prove effective for developing Hsp60-targeting drugs for anticancer therapy.
Spermatogenesis arrest caused by conditional deletion of Hsp90α in adult mice
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Chiaki Kajiwara
It is controversial whether a functional androgen receptor (AR on germ cells, including spermatogonia, is essential for their development into sperm and, thus, initiation and maintenance of spermatogenesis. It was recently shown that many spermatocytes underwent apoptosis in the testes of Hsp90α KO mice. We had generated Hsp90α KO mice independently and confirmed this phenotype. However, the important question of whether Hsp90α is required to maintain spermatogenesis in adult mice in which testicular maturation is already completed could not be addressed using these conventional KO mice. To answer this question, we generated a tamoxifen-inducible deletion mutant of Hsp90α and found that conditional deletion of Hsp90α in adult mice caused even more severe apoptosis in germ cells beyond the pachytene stage, leading to complete arrest of spermatogenesis and testicular atrophy. Importantly, immunohistochemical analysis revealed that AR expression in WT testis was more evident in spermatogonia than in spermatocytes, whereas its expression was aberrant and ectopic in Hsp90α KO testis, raising the possibility that an AR abnormality in primordial germ cells is involved in spermatogenesis arrest in the Hsp90α KO mice. Our results suggest that the AR, specifically chaperoned by Hsp90α in spermatogonia, is critical for maintenance of established spermatogenesis and for survival of spermatocytes in adult testis, in addition to setting the first wave of spermatogenesis before puberty.
Impact of ecologically relevant heat shocks on Hsp developmental function in the vetigastropod Haliotis asinina.
Gunter, Helen M; Degnan, Bernard M
Heat shock proteins (Hsps) are essential for cellular maintenance, normal differentiation and morphogenesis, and protection against a range of environmental stresses. It is unknown which of these roles takes precedence when they are required simultaneously. Here we examined the impact of thermal stress on the complex developmental expression patterns of HasHsp70 and HasHsp90A in the vetigastropod Haliotis asinina. We find that near-lethal heat shocks do not alter the spatial demarcation of Hsp expression despite such treatments impacting on the external character of the embryos. Using a suite of molecular markers that are both coexpressed with the Hsps (i.e. in ventrolateral ectoderm and prototroch) and expressed in tissues that have lower (basal) Hsp expression (e.g. serotonergic nervous system and shell gland), we determined that Hsp-expressing tissues do not incur markedly less thermal damage than adjacent tissues. To explore the relationship of Hsp expression with sensitivity of specific cell territories to heat shock, we focused on the formation of the prototroch, a tissue where HasHsp70 and HasHsp90A are coexpressed. By heat shocking at specific developmental stages, we determined that the most sensitive period of prototroch development is during its early specification and differentiation, which overlaps with the time the Hsps are expressed at their highest levels in these cells. This correlation is consistent with heat shock impairing the function of Hsps in regions of the H. asinina embryo undergoing morphogenesis.
Quercetin suppresses heat shock-induced nuclear translocation of Hsp72
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Antoni Gawron
Full Text Available The effect of quercetin and heat shock on the Hsp72 level and distribution in HeLa cells was studied by Western blotting, indirect immunofluorescence and immunogold electron microscopy. In control cells and after quercetin treatment, Hsp72 was located both in the cytoplasm and in the nucleus in comparable amounts. After hyperthermia, the level of nuclear Hsp72 raised dramatically. Expression of Hsp72 in cytoplasm was also higher but not to such extent as that observed in the nucleus. Preincubation of heated cells with quercetin inhibited strong Hsp72 expression observed after hyperthermia and changed the intracellular Hsp72 distribution. The cytoplasmic level of protein exceeded the nuclear one, especially around the nucleus, where the coat of Hsp72 was noticed. Observations indicating that quercetin was present around and in the nuclear envelope suggested an involvement of this drug in the inhibition of nuclear translocation. Our results indicate that pro-apoptotic activity of quercetin may be correlated not only with the inhibition of Hsp72 expression but also with suppression of its migration to the nucleus.
Reduced glycogen availability is associated with an elevation in HSP72 in contracting human skeletal muscle
DEFF Research Database (Denmark)
Febbraio, Mark A; Steensberg, Adam; Walsh, Rory;
glycogen content was 40 % lower in the depleted compared with the control leg and this difference was maintained throughout the experiment (P < 0.05; main treatment effect). Neither HSP72 gene nor protein expression was different pre-exercise. However, both HSP72 gene and protein increased (P < 0.05) post...
The FNIP co-chaperones decelerate the Hsp90 chaperone cycle and enhance drug binding
Woodford, Mark R.; Dunn, Diana M.; Blanden, Adam R.; Capriotti, Dante; Loiselle, David; Prodromou, Chrisostomos; Panaretou, Barry; Hughes, Philip F.; Smith, Aaron; Ackerman, Wendi; Haystead, Timothy A.; Loh, Stewart N.; Bourboulia, Dimitra; Schmidt, Laura S.; Marston Linehan, W.; Bratslavsky, Gennady; Mollapour, Mehdi
Heat shock protein-90 (Hsp90) is an essential molecular chaperone in eukaryotes involved in maintaining the stability and activity of numerous signalling proteins, also known as clients. Hsp90 ATPase activity is essential for its chaperone function and it is regulated by co-chaperones. Here we show that the tumour suppressor FLCN is an Hsp90 client protein and its binding partners FNIP1/FNIP2 function as co-chaperones. FNIPs decelerate the chaperone cycle, facilitating FLCN interaction with Hsp90, consequently ensuring FLCN stability. FNIPs compete with the activating co-chaperone Aha1 for binding to Hsp90, thereby providing a reciprocal regulatory mechanism for chaperoning of client proteins. Lastly, downregulation of FNIPs desensitizes cancer cells to Hsp90 inhibitors, whereas FNIPs overexpression in renal tumours compared with adjacent normal tissues correlates with enhanced binding of Hsp90 to its inhibitors. Our findings suggest that FNIPs expression can potentially serve as a predictive indicator of tumour response to Hsp90 inhibitors. PMID:27353360
Cell-surface expression of Hsp70 on hematopoietic cancer cells after inhibition of HDAC activity
DEFF Research Database (Denmark)
Jensen, Helle; Andresen, Lars; Hansen, Karen Aagaard;
We show that inhibition of HDAC activity leads to surface expression of Hsp70 on various hematopoietic cancer cells, an occurance that was not observed on naïve or activated peripheral blood cells. HDAC inhibitor-mediated Hsp70 surface expression was confined to the apoptotic Annexin V-positive c......We show that inhibition of HDAC activity leads to surface expression of Hsp70 on various hematopoietic cancer cells, an occurance that was not observed on naïve or activated peripheral blood cells. HDAC inhibitor-mediated Hsp70 surface expression was confined to the apoptotic Annexin V......-positive cells and blocked by inhibition of apoptosis. Other chemotherapeutic inducers of apoptosis such as etoposide and camptothecin also led to a robust induction of Hsp70 surface expression. Hsp70 expression was, however, not caused by induction of apoptosis per se, as activated CD4 T cells remained Hsp70...... surface-negative despite effective induction of apoptosis. Interestingly, inhibition of endolysosomes or normal ER/Golgi transport did not affect Hsp70 surface expression. Intracellular calcium and the transcription factor Sp1, which has been shown previously to be important for the intracellular stress...
Regulation of CLC-1 chloride channel biosynthesis by FKBP8 and Hsp90β
Peng, Yi-Jheng; Huang, Jing-Jia; Wu, Hao-Han; Hsieh, Hsin-Ying; Wu, Chia-Ying; Chen, Shu-Ching; Chen, Tsung-Yu; Tang, Chih-Yung
Mutations in human CLC-1 chloride channel are associated with the skeletal muscle disorder myotonia congenita. The disease-causing mutant A531V manifests enhanced proteasomal degradation of CLC-1. We recently found that CLC-1 degradation is mediated by cullin 4 ubiquitin ligase complex. It is currently unclear how quality control and protein degradation systems coordinate with each other to process the biosynthesis of CLC-1. Herein we aim to ascertain the molecular nature of the protein quality control system for CLC-1. We identified three CLC-1-interacting proteins that are well-known heat shock protein 90 (Hsp90)-associated co-chaperones: FK506-binding protein 8 (FKBP8), activator of Hsp90 ATPase homolog 1 (Aha1), and Hsp70/Hsp90 organizing protein (HOP). These co-chaperones promote both the protein level and the functional expression of CLC-1 wild-type and A531V mutant. CLC-1 biosynthesis is also facilitated by the molecular chaperones Hsc70 and Hsp90β. The protein stability of CLC-1 is notably increased by FKBP8 and the Hsp90β inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) that substantially suppresses cullin 4 expression. We further confirmed that cullin 4 may interact with Hsp90β and FKBP8. Our data are consistent with the idea that FKBP8 and Hsp90β play an essential role in the late phase of CLC-1 quality control by dynamically coordinating protein folding and degradation. PMID:27580824
Functional analysis of the Hikeshi-like protein and its interaction with HSP70 in Arabidopsis
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Koizumi, Shinya; Ohama, Naohiko; Mizoi, Junya [Laboratory of Plant Molecular Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Shinozaki, Kazuo [RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, Kanagawa 230-0045 (Japan); Yamaguchi-Shinozaki, Kazuko, E-mail: firstname.lastname@example.com [Laboratory of Plant Molecular Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan)
Highlights: • HKL, a Hikeshi homologous gene is identified in Arabidopsis. • HKL interacts with two HSP70 isoforms and regulates the subcellular localization of HSC70-1. • The two HSP70 translocate into nucleus in response to heat stress. • Overexpression of HKL confers thermotolerance in transgenic plants. - Abstract: Heat shock proteins (HSPs) refold damaged proteins and are an essential component of the heat shock response. Previously, the 70 kDa heat shock protein (HSP70) has been reported to translocate into the nucleus in a heat-dependent manner in many organisms. In humans, the heat-induced translocation of HSP70 requires the nuclear carrier protein Hikeshi. In the Arabidopsis genome, only one gene encodes a protein with high homology to Hikeshi, and we named this homolog Hikeshi-like (HKL) protein. In this study, we show that two Arabidopsis HSP70 isoforms accumulate in the nucleus in response to heat shock and that HKL interacts with these HSP70s. Our histochemical analysis revealed that HKL is predominantly expressed in meristematic tissues, suggesting the potential importance of HKL during cell division in Arabidopsis. In addition, we show that HKL regulates HSP70 localization, and HKL overexpression conferred thermotolerance to transgenic Arabidopsis plants. Our results suggest that HKL plays a positive role in the thermotolerance of Arabidopsis plants and cooperatively interacts with HSP70.
Assay strategies for the discovery and validation of therapeutics targeting Brugia pahangi Hsp90.
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Tony Taldone
Full Text Available The chemotherapy of lymphatic filariasis relies upon drugs such as diethylcarbamazine and ivermectin that largely target the microfilarial stages of the parasite, necessitating continued treatment over the long reproductive life span of the adult worm. The identification of compounds that target adult worms has been a long-term goal of WHO. Here we describe a fluorescence polarization assay for the identification of compounds that target Hsp90 in adult filarial worms. The assay was originally developed to identify inhibitors of Hsp90 in tumor cells, and relies upon the ability of small molecules to inhibit the binding of fluorescently labelled geldanamycin to Hsp90. We demonstrate that the assay works well with soluble extracts of Brugia, while extracts of the free-living nematode C. elegans fail to bind the probe, in agreement with data from other experiments. The assay was validated using known inhibitors of Hsp90 that compete with geldanamycin for binding to Hsp90, including members of the synthetic purine-scaffold series of compounds. The efficacy of some of these compounds against adult worms was confirmed in vitro. Moreover, the assay is sufficiently sensitive to differentiate between binding of purine-scaffold compounds to human and Brugia Hsp90. The assay is suitable for high-throughput screening and provides the first example of a format with the potential to identify novel inhibitors of Hsp90 in filarial worms and in other parasitic species where Hsp90 may be a target.
Determination of the dose rapidity of a {sup 90} Sr beta radiation source using thermoluminescent dosemeters; Determinacion de la rapidez de dosis de una fuente de radiacion beta de {sup 90}Sr usando dosimetros termoluminiscentes
Energy Technology Data Exchange (ETDEWEB)
Gonzalez M, P.R.; Azorin N, J.; Rivera M, T. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)
The thermoluminescent dosemeters developed in Mexico, have been used efficiently in environmental and personal dosimetry. When the dose rate of some source is not known can be estimated with the use of thermoluminescent dosemeters taking in account the geometrical array used in the irradiations for reproducibility of the results in posterior irradiations. In this work it was estimated the dose rate of a {sup 90} Sr-{sup 90} Y beta radiation source which is property of the Nuclear Sciences Institute, UNAM, therefore it was l ended to the Metropolitan Autonomous University- Iztapalapa Unit for the characterization of new Tl materials, taking account of the institutional collaboration agreements. (Author)
Mild eccentric exercise increases Hsp72 content in skeletal muscles from adult and late middle-aged rats
Lewis, Evan J. H.; Ramsook, Andrew H.; Locke, Marius; Amara, Catherine E.
The loss of muscle mass with age or sarcopenia contributes to increased morbidity and mortality. Thus, preventing muscle loss with age is important for maintaining health. Hsp72, the inducible member of the Hsp70 family, is known to provide protection to skeletal muscle and can be increased by exercise. However, ability to increase Hsp72 by exercise is intensity-dependent and appears to diminish with advanced age. Thus, other exercise modalities capable of increasing HSP content and potential...
The Effects of Venlafaxine and Dexamethasone on the Expression of HSP70 in Rat C6 Glioma Cells
Yu, Jaehak; Roh, Sungwon; Lee, Jun-Seok; Yang, Byung-Hwan; Choi, Mi Ran; Chai, Young Gyu; Kim, Seok Hyeon
Objective The present study aimed to determine the intracellular action of the antidepressant, venlafaxine, in C6 glioma cells using heat shock protein 70 (HSP70) immunocytochemistry and HSP70 Western blots; HSP70 is known to be associated with stress and depression. Methods The extent of HSP70 expression was measured after rat C6 glioma cells were treated with 1) dexamethasone only, 2) venlafaxine only, 3) simultaneous venlafaxine and dexamethasone, or 4) dexamethasone after venlafaxine pret...
Relative thermoluminescent efficiencies proton/gamma and helium/gamma of peaks of high temperature in TLD-100 dosemeters
International Nuclear Information System (INIS)
The increase of the applications of ion beams in radiotherapy treatments has generated interest in the study of the thermoluminescent materials (TL) that allow to determine the applied doses. A way to quantify the TL response from these materials to ions is by means of the relative thermoluminescent efficiency. In the group of Thermoluminescent dosimetry of the Institute of Physics of the UNAM (IFUNAM) the thermoluminescent response of the TLD-100 dosemeters has been studied, which present a glow curve characteristic with several peaks that correspond to traps and luminescent centers in the material. The stable peaks know each other as 4, 5, 6a, 6b, 7, 8, 9 and 10. The efficiencies should be measured using the response so much to the radiation of interest (in this case protons and helium ions) as the response to gamma radiation. In previous works with ions of low energy taken place in the Pelletron accelerator of the IFUNAM was only measured the TL efficiency for the peak 5 and the total signal. It had not been possible to measure the efficiency of the peaks of high temperature (6a-10) because, for the gamma radiation, the peaks of high temperature show very small signals; however, recently Massillon carries out measures of efficiency TL of peaks of high temperature for ions of intermediate energy using a protocol special of reading and of deconvolution that allows to measure the signals coming from the peaks of high temperature. In this work is implemented this same protocol to complete the study of TL efficiencies at low energy of protons and helium and to determine if the values of efficiency depend on the used reading protocol. For it is reported it measures of the relative efficiency of the peaks of high temperature from the TLD-100 exposed to protons of 1.5 MeV and nuclei of helium of 3 and 7.5 MeV. (Author)
Increased levels of IgG antibodies against human HSP60 in patients with spondyloarthritis.
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Astrid Hjelholt
Full Text Available Spondyloarthritis (SpA comprises a heterogeneous group of inflammatory diseases, with strong association to human leukocyte antigen (HLA-B27. A triggering bacterial infection has been considered as the cause of SpA, and bacterial heat shock protein (HSP seems to be a strong T cell antigen. Since bacterial and human HSP60, also named HSPD1, are highly homologous, cross-reactivity has been suggested in disease initiation. In this study, levels of antibodies against bacterial and human HSP60 were analysed in SpA patients and healthy controls, and the association between such antibodies and disease severity in relation to HLA-B27 was evaluated.Serum samples from 82 patients and 50 controls were analysed by enzyme-linked immunosorbent assay (ELISA for immunoglobulin (IgG1, IgG2, IgG3 and IgG4 antibodies against human HSP60 and HSP60 from Chlamydia trachomatis, Salmonella enteritidis and Campylobacter jejuni. Disease severity was assessed by the clinical scorings Bath Ankylosing Spondylitis Disease Activity Index (BASDAI, Bath Ankylosing Spondylitis Functional Index (BASFI and Bath Ankylosing Spondylitis Metrology Index (BASMI. Levels of IgG1 and IgG3 antibodies against human HSP60, but not antibodies against bacterial HSP60, were elevated in the SpA group compared with the control group. Association between IgG3 antibodies against human HSP60 and BASMI was shown in HLA-B27⁺ patients. Only weak correlation between antibodies against bacterial and human HSP60 was seen, and there was no indication of cross-reaction. These results suggest that antibodies against human HSP60 is associated with SpA, however, the theory that antibodies against human HSP60 is a specific part of the aetiology, through cross-reaction to bacterial HSP60, cannot be supported by results from this study. We suggest that the association between elevated levels of antibodies against human HSP60 and disease may reflect a general activation of the immune system and an increased
温室粉虱和烟粉虱3个隐种中热激蛋白基因hsp70和hsp90含量的比较分析%Comparative analysis of the copy numbers of hsp70 and hsp90 in Trialeurodes vaporariorum and three cryptic species of Bemisia tabaci complex (Hemiptera: Aleyrodidae)
Institute of Scientific and Technical Information of China (English)
韦姣; 吕志创; 王韧; 万方浩
[目的]昆虫适应新环境的能力与其对温度的耐受能力密切相关.热激蛋白HSP70和HSP90具有提高生物体温度耐受性的功能.烟粉虱Bemisia tabaci (Gennadius)不同隐种和不同种粉虱对温度的适应能力有差异,这与它们的热激蛋白基因拷贝数的差异可能相关.[方法]利用实时荧光定量PCR方法,检测入侵型烟粉虱MED隐种和MEAM1隐种、本地型烟粉虱AsiaⅡ1隐种以及温室粉虱Trialeurodes vaporariorum (Westwood)基因组DNA中热激蛋白基因hsp70和hsp90的拷贝数.[结果]不同种类的粉虱和烟粉虱不同隐种体内的hsp70和hsp90的含量均有较大差异,其中hsp70和hsp90拷贝数在入侵型烟粉虱MED和MEAM1隐种中含量较其他两种均高,而在土著种AsiaⅡ1隐种中含量最低,在温室粉虱中居中.此外,相同物种雌雄成虫hsp70和hsp90的拷贝数也不同,雌虫hsp70和hsp90拷贝数约为雄虫的2倍.[结论]不同种粉虱及烟粉虱不同隐种的hsp70和hsp90的拷贝数可能与其耐热性差异相关.本研究为解释不同种粉虱、烟粉虱不同隐种及其不同性别的耐热性差异机制提供了进一步的依据.
Expression and Purification of Goose HSP70 and Compound Formation with Virus Polypeptide
Institute of Scientific and Technical Information of China (English)
WANG Bao-wei; WU Xiao-ping; ZHANG Xu-hui; JIA Xiao-hui; ZHANG Ming-ai; LONG Fang-yu; YANG Zhi-gang; WANG Lei
The experiment was conducted to study the specific expression of HSP70 caused by heat shock,HSP70 purification and the characteristics of coalescence with antigenic peptide in the formation of the complex.Sixty healthy 6-week-old male Wulong geese were selected and randomly divided into three groups.The control group was slaughtered without heat treatment.Treatment group 1 was shocked with an acute heat treatment at(42±1)℃ for 5 h before they were immediately slaughtered.Treatment group 2 was kept for 12 h after the heat treatment under normal conditions in order to recover and was then slaughtered.Cardiac tissue was taken in order to make paraffin sections for the immunohistochemistry experiment and the liver tissue was used to purify HSP70.The geese heart HSP70 expression differences in the three groups were determined and at the same time the experiments of HSP70 purification and appraisal in the liver tissue were carried on.HSP70 purification and synthesis of HBV PreS1 multi-peptides unified the complex,which was determined by bi-specific antibody enzyme-linked immune sandwich assay.The results indicated that widespread HSP70 positive pellets in the cardiac muscle were found under hot shock conditions.HSP70 expression in the treatment group 1 was centered in the karyotheca and its periphery,but in treatment group 2,it was centered in the surrounding cell membrane.The HSP70 purification could be obtained through two sets of purification plans;both the synthesis peptide and the HSP70 purification form the complex under certain conditions.The double antibody sandwich ELISA technique was applied to detect if the complex had been formed.Positive results showed that the complex was formed.The specific expression of HSP70 under heat shock shifted with time,suggesting that HSP70 possibly had some function in cell protection.High-purity HSP70 protein can be obtained under low-pressure chromatography conditions,and in comparison with each other,it was better in the
A platform to view huntingtin exon 1 aggregation flux in the cell reveals divergent influences from chaperones hsp40 and hsp70.
Ormsby, Angelique R; Ramdzan, Yasmin M; Mok, Yee-Foong; Jovanoski, Kristijan D; Hatters, Danny M
Our capacity for tracking how misfolded proteins aggregate inside a cell and how different aggregation states impact cell biology remains enigmatic. To address this, we built a new toolkit that enabled the high throughput tracking of individual cells enriched with polyglutamine-expanded Htt exon 1 (Httex1) monomers, oligomers, and inclusions using biosensors of aggregation state and flow cytometry pulse shape analysis. Supplemented with gel filtration chromatography and fluorescence-adapted sedimentation velocity analysis of cell lysates, we collated a multidimensional view of Httex1 aggregation in cells with respect to time, polyglutamine length, expression levels, cell survival, and overexpression of protein quality control chaperones hsp40 (DNAJB1) and hsp70 (HSPA1A). Cell death rates trended higher for Neuro2a cells containing Httex1 in inclusions than with Httex1 dispersed through the cytosol at time points of expression over 2 days. hsp40 stabilized monomers and suppressed inclusion formation but did not otherwise change Httex1 toxicity. hsp70, however, had no major effect on aggregation of Httex1 but increased the survival rate of cells with inclusions. hsp40 and hsp70 also increased levels of a second bicistronic reporter of Httex1 expression, mKate2, and increased total numbers of cells in culture, suggesting these chaperones partly rectify Httex1-induced deficiencies in quality control and growth rates. Collectively, these data suggest that Httex1 overstretches the protein quality control resources and that the defects can be partly rescued by overexpression of hsp40 and hsp70. Importantly, these effects occurred in a pronounced manner for soluble Httex1, which points to Httex1 aggregation occurring subsequently to more acute impacts on the cell. PMID:24196953
A Platform to View Huntingtin Exon 1 Aggregation Flux in the Cell Reveals Divergent Influences from Chaperones hsp40 and hsp70*
Ormsby, Angelique R.; Ramdzan, Yasmin M.; Mok, Yee-Foong; Jovanoski, Kristijan D.; Hatters, Danny M.
Our capacity for tracking how misfolded proteins aggregate inside a cell and how different aggregation states impact cell biology remains enigmatic. To address this, we built a new toolkit that enabled the high throughput tracking of individual cells enriched with polyglutamine-expanded Htt exon 1 (Httex1) monomers, oligomers, and inclusions using biosensors of aggregation state and flow cytometry pulse shape analysis. Supplemented with gel filtration chromatography and fluorescence-adapted sedimentation velocity analysis of cell lysates, we collated a multidimensional view of Httex1 aggregation in cells with respect to time, polyglutamine length, expression levels, cell survival, and overexpression of protein quality control chaperones hsp40 (DNAJB1) and hsp70 (HSPA1A). Cell death rates trended higher for Neuro2a cells containing Httex1 in inclusions than with Httex1 dispersed through the cytosol at time points of expression over 2 days. hsp40 stabilized monomers and suppressed inclusion formation but did not otherwise change Httex1 toxicity. hsp70, however, had no major effect on aggregation of Httex1 but increased the survival rate of cells with inclusions. hsp40 and hsp70 also increased levels of a second bicistronic reporter of Httex1 expression, mKate2, and increased total numbers of cells in culture, suggesting these chaperones partly rectify Httex1-induced deficiencies in quality control and growth rates. Collectively, these data suggest that Httex1 overstretches the protein quality control resources and that the defects can be partly rescued by overexpression of hsp40 and hsp70. Importantly, these effects occurred in a pronounced manner for soluble Httex1, which points to Httex1 aggregation occurring subsequently to more acute impacts on the cell. PMID:24196953
Dynamic Analysis of the Expression of HSP70 during Experimental Tooth Movement in Rats
Institute of Scientific and Technical Information of China (English)
In this study, the expression of HSP70 during experimental tooth movement was dynamically observed and the relationship between HSP70 and orthodontic periodontal tissue remodeling were observed. The orthodontic appliance was placed between the right maxillary first molar and maxillary central incisors of adult SD rats to establish a rat molar movement model. Immunohistochemistry was performed 1, 3, 5, 7 and 14 day(s) after orthodontic force application to observe the expression and localization of inducible HSP70. The expression of HSP70 was strongly positive in the early stage of the tooth movement, became gradually less positive, and was weakly positive in the restoration stage. There was difference in staining pattern between different parts of PDL during the same period. These results suggest that the expression of HSP70 and difference in staining pattern among different parts of PDL during orthodontic tooth movement in rats may be implicated in stress response and remodeling of periodontal tissue.
Expression of HSP70 in Peripheral Lymphocytes of the Patients with Allergic Rhinitis
Institute of Scientific and Technical Information of China (English)
刘立思; 肖成峰; 张明; 程磊; 王鄂芬; 邬堂春
The expression levels of heat shock protein 70 (HSP70) from peripheral lymphocytes ofthe patients with allergic rhinitis (AR) and the clinical implication were investigated. In the morn-ing, 3 ml of fasting venous blood was taken out. The lymphocytes were isolated by using Ficoll-Hypaque and the expression of HSP70 in the lymphocytes was detected by using Western blot. Inthe AR patients the HSP70 level (41.49± 15.77 integrated optical density, IOD) were significantlyhigher than that in the control group (23.89±10. 13 IOD, P<0.05). Western blot demonstratedthat HSP70 bands in AR patients were more intensive than those in the control group. It was con-cluded that the elevated HSP70 level in peripheral lymphocytes of the AR patients might contributeto the development of AR.
Adult Heat Tolerance Variation in Drosophila melanogaster is Not Related to Hsp70 Expression
DEFF Research Database (Denmark)
Jensen, Louise Toft; Cockerell, Fiona Elizabeth; Kristensen, Torsten Nygaard;
Expression of heat-inducible Hsp70 is considered closely linked to thermotolerance in Drosophila melanogaster and other ectotherms. However, intra-specific variation of Hsp70 expression levels and its relationship to heat resistance has only been investigated in a few studies. Although...... in adult heat tolerance. Therefore, although Hsp70 expression is a major component of the cellular heat stress response, its influence on intra-specific heat tolerance variation may be life-stage specific. J. Exp. Zool. 313A:35-44, 2010. © 2009 Wiley-Liss, Inc...... in Drosophila larvae Hsp70 expression may be a key determinant of heat tolerance, the evidence for this in adults is equivocal. We therefore examined heat-induced Hsp70 expression and several measurements of adult heat tolerance in three independent collections of D. melanogaster, measured in three laboratories...
Expression analysis of NOS family and HSP genes during thermal stress in goat ( Capra hircus)
Yadav, Vijay Pratap; Dangi, Satyaveer Singh; Chouhan, Vikrant Singh; Gupta, Mahesh; Dangi, Saroj K.; Singh, Gyanendra; Maurya, Vijay Prakash; Kumar, Puneet; Sarkar, Mihir
Approximately 50 genes other than heat shock protein (HSP) expression changes during thermal stress. These genes like nitric oxide synthase (NOS) need proper attention and investigation to find out their possible role in the adaptation to thermal stress in animals. So, the present study was undertaken to demonstrate the expressions of inducible form type II NOS (iNOS), endothelial type III NOS (eNOS), constitutively expressed enzyme NOS (cNOS), HSP70, and HSP90 in peripheral blood mononuclear cells (PBMCs) during different seasons in Barbari goats. Real-time polymerase chain reaction, western blot, and immunocytochemistry were applied to investigate messenger RNA (mRNA) expression, protein expression, and immunolocalization of examined factors. The mRNA and protein expressions of iNOS, eNOS, cNOS, HSP70, and HSP90 were significantly higher ( P cellular integrity and homeostasis in goats.
Crosstalk between p38, Hsp25 and Akt in spinal motor neurons after sciatic nerve injury
Murashov, A. K.; Ul Haq, I.; Hill, C.; Park, E.; Smith, M.; Wang, X.; Wang, X.; Goldberg, D. J.; Wolgemuth, D. J.
The p38 stress-activated protein kinase pathway is involved in regulation of phosphorylation of Hsp25, which in turn regulates actin filament dynamic in non-neuronal cells. We report that p38, Hsp25 and Akt signaling pathways were specifically activated in spinal motor neurons after sciatic nerve axotomy. The activation of the p38 kinase was required for induction of Hsp25 expression. Furthermore, Hsp25 formed a complex with Akt, a member of PI-3 kinase pathway that prevents neuronal cell death. Together, our observations implicate Hsp25 as a central player in a complex system of signaling that may both promote regeneration of nerve fibers and prevent neuronal cell death in the injured spinal cord.
Roles of Hsp70s in Stress Responses of Microorganisms, Plants, and Animals
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Anmin Yu
Full Text Available Hsp70s (heat shock protein 70s are a class of molecular chaperones that are highly conserved and ubiquitous in organisms ranging from microorganisms to plants and humans. Most research on Hsp70s has focused on the mechanisms of their functions as molecular chaperones, but recently, studies on stress responses are coming to the forefront. Hsp70s play key roles in cellular development and protecting living organisms from environmental stresses such as heat, drought, salinity, acidity, and cold. Moreover, functions of human Hsp70s are related to diseases including neurological disorders, cancer, and virus infection. In this review, we provide an overview of the specific roles of Hsp70s in response to stress, particularly abiotic stress, in all living organisms.
Dexamethasone regulates CFTR expression in Calu-3 cells with the involvement of chaperones HSP70 and HSP90.
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Luiz Felipe M Prota
Full Text Available BACKGROUND: Dexamethasone is widely used for pulmonary exacerbation in patients with cystic fibrosis, however, not much is known about the effects of glucocorticoids on the wild-type cystic fibrosis channel transmembrane regulator (CFTR. Our aim was to determine the effects of dexamethasone treatment on wild-type CFTR expression. METHODS AND RESULTS: Dose-response (1 nM to 10 µM and time course (3 to 48 h curves were generated for dexamethasone for mRNA expression in Calu-3 cells using a real-time PCR. Within 24 h, dexamethasone (10 nM showed a 0.3-fold decrease in CFTR mRNA expression, and a 3.2-fold increase in αENaC mRNA expression compared with control groups. Dexamethasone (10 nM induced a 1.97-fold increase in the total protein of wild-type CFTR, confirmed by inhibition by mifepristone. To access surface protein expression, biotinylation followed by Western blotting showed that dexamethasone treatment led to a 2.35-fold increase in the amount of CFTR in the cell surface compared with the untreated control groups. Once protein translation was inhibited with cycloheximide, dexamethasone could not increase the amount of CFTR protein. Protein stability was assessed by inhibition of protein synthesis with cycloheximide (50 µg/ml at different times in cells treated with dexamethasone and in untreated cells. Dexamethasone did not alter the degradation of wild-type CFTR. Assessment of the B band of CFTR within 15 min of metabolic pulse labeling showed a 1.5-fold increase in CFTR protein after treatment with dexamethasone for 24 h. Chaperone 90 (HSP90 binding to CFTR increased 1.55-fold after treatment with dexamethasone for 24 h, whereas chaperone 70 (HSP70 binding decreased 0.30 fold in an immunoprecipitation assay. CONCLUSION: Mature wild-type CFTR protein is regulated by dexamethasone post transcription, involving cotranslational mechanisms with HSP90 and HSP70, which enhances maturation and expression of wild-type CFTR.
Molecular cloning and expression analysis of heat shock protein 20 (HSP20) from the pearl oyster Pinctada martensii.
Lei, Q N; Wu, Y Y; Liang, H Y; Wang, Z X; Zheng, Z; Deng, Y W
Small heat shock proteins (HSPs) are molecular chaperones with ATP-independent properties. They are involved in a variety of physiological and stress processes. In this study, the full-length HSP 20 (HSP20) from Pinctada martensii, designated as PmHSP20, was obtained from hemocytes using rapid amplification of cDNA ends technology. The PmHSP20 cDNA was 952 bp in length, containing an open reading frame of 534 bp that encoded 177-amino acid residues, with an isoelectric point of 5.86 and molecular weight of 20.24 kDa. The sequence of this deduced polypeptide contained typical structure and function domains conserved in the HSP20 family, providing evidence that PmHSP20 belongs to the HSP20 family. The PmHSP20 mRNA expression levels were detected in various tissues of P. martensii and in hemocytes after challenges with the bacteria Vibrio harveyi and lipopolysaccharide (LPS) using quantitative real-time polymerase chain reaction amplification. The results indicated that PmHSP20 is constitutively expressed in all tissues tested and might be involved in the immune response. The upregulation of PmHSP20 after V. harveyi and LPS challenge suggests that PmHSP20 plays an important role in anti-bacterial immunity. Studies on PmHSP20 are a valuable resource to further explore the immune system in pearl oysters and might enhance our knowledge of molluscan innate immunity. PMID:27420982
The molecular chaperone Hsp70 activates protein phosphatase 5 (PP5) by binding the tetratricopeptide repeat (TPR) domain.
Connarn, Jamie N; Assimon, Victoria A; Reed, Rebecca A; Tse, Eric; Southworth, Daniel R; Zuiderweg, Erik R P; Gestwicki, Jason E; Sun, Duxin
Protein phosphatase 5 (PP5) is auto-inhibited by intramolecular interactions with its tetratricopeptide repeat (TPR) domain. Hsp90 has been shown to bind PP5 to activate its phosphatase activity. However, the functional implications of binding Hsp70 to PP5 are not yet clear. In this study, we find that both Hsp90 and Hsp70 bind to PP5 using a luciferase fragment complementation assay. A fluorescence polarization assay shows that Hsp90 (MEEVD motif) binds to the TPR domain of PP5 almost 3-fold higher affinity than Hsp70 (IEEVD motif). However, Hsp70 binding to PP5 stimulates higher phosphatase activity of PP5 than the binding of Hsp90. We find that PP5 forms a stable 1:1 complex with Hsp70, but the interaction appears asymmetric with Hsp90, with one PP5 binding the dimer. Solution NMR studies reveal that Hsc70 and PP5 proteins are dynamically independent in complex, tethered by a disordered region that connects the Hsc70 core and the IEEVD-TPR contact area. This tethered binding is expected to allow PP5 to carry out multi-site dephosphorylation of Hsp70-bound clients with a range of sizes and shapes. Together, these results demonstrate that Hsp70 recruits PP5 and activates its phosphatase activity which suggests dual roles for PP5 that might link chaperone systems with signaling pathways in cancer and development.
Investigating hsp Gene Expression in Liver of Channa striatus under Heat Stress for Understanding the Upper Thermal Acclimation
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Gopal Krishna Purohit
Full Text Available Changes in hsp gene expression profiles in murrel Channa striatus experimentally exposed to temperature stress (36°C for 4, 15, and 30 days were investigated; fish collected from aquaculture ponds and maintained in laboratory at the pond temperature (25 ± 1°C served as control. Channa collected from a hot spring runoff (36°C was included in the study to examine the hsp profiles beyond 30 days of exposure. Gene expression analyses of a battery of hsps in liver tissues were carried out by quantitative RT-PCR and protein expressions were analyzed by immunoblotting. hsps could be grouped into three clusters based on similarity in response to heat stress: hsp70, hsp78, and hsp60, whose transcript level continued to increase with duration of exposure; hsp90 and hsp110 that increased to a much higher level and then decreased; hsp27 and hsp47 that did not significantly vary as compared to control. The results suggest that Hsp70, Hsp78, and Hsp60 are involved in thermal acclimation and long term survival at high temperature. Fish living in the hot spring runoff appears to continuously express hsps that can be approximated by long term induction of hsps in farmed fish if temperature of their environment is raised to 36°C.
Zinc-L-carnosine binds to molecular chaperone HSP70 and inhibits the chaperone activity of the protein.
Haga, Asami; Okamoto, Tomoya; Yamada, Shintaroh; Kubota, Toshihiko; Sanpei, Ann; Takahashi, Shota; Nakayama, Masahiro; Nagai, Miki; Otaka, Michiro; Miyazaki, Toshio; Nunomura, Wataru; Grave, Ewa; Itoh, Hideaki
In this study, we have investigated the specific binding proteins of Zinc-L-carnosine (Polaprezinc) using Polaprezinc-affinity column chromatography in vitro. A protein having a 70-kDa molecular mass was eluted by the linear gradient of 0-1.0 mM Polaprezinc from the affinity column and the protein was identified as the molecular chaperone HSP70 by immunoblotting. The chaperone activity of HSP70 was completely suppressed by Polaprezinc. The ATPase activity of HSP70 was affected to some extent by the reagent. In the circular dichroism (CD) spectrum, the secondary structure of HSP70 was changed in the presence of Polaprezinc, i.e. it decreased in the α-helix. We have determined the Polaprezinc-binding domain of HSP70 by using recombinant HSP70N- and C-domains. Although Polaprezinc could bind to both the N-terminal and the C-terminal of HSP70, the HSP70N-domain has a high affinity to the drug. Regarding the peptide cleavage of the HSP70N- and C-domains with proteinase K, the intact HSP70N still remained in the presence of Polaprezinc. On the other hand, the quantity of the intact C-domain slightly decreased under the same conditions along with the newly digested small peptides appeared. It has been suggested that Polaprezinc binds to HSP70 especially in the N-domains, suppresses the chaperone activity and delays an ATPase activities of HSP70. PMID:23687308
HDJC9, a novel human type C DnaJ/HSP40 member interacts with and cochaperones HSP70 through the J domain
International Nuclear Information System (INIS)
HSP40s are a subfamily of heat shock proteins (HSPs) and play important roles in regulation of cell proliferation, survival and apoptosis by serving as chaperones for HSP70s. Up to date hundreds of HSP40 proteins derived from various species ranging from Escherichia coli to homo sapiens have been identified. Here we report the cloning and characterization of a novel human type C DnaJ homologue, HDJC9, containing a typical N-terminal J domain. HDJC9 is upregulated at both mRNA and protein levels upon various stress and mitogenic stimulations. HDJC9 is mainly localized in cell nuclei under normal culture conditions while it is transported into cytoplasm and plasma membrane upon heat shock stress through a non-classical and lipid-dependent pathway. HDJC9 can interact with HSP70s and activate the ATPase activity of HSP70s, both of which are dependent on the J domain. Our data suggest that HDJC9 is a novel cochaperone for HSP70s
DEFF Research Database (Denmark)
Wenzel, Henrik
-20% for transportation. At that time, the electric car/fuel cell car has probably had time enough to mature, and it has a much higher energy efficiency. Therefore, bio-ethanol is not the right intermediate (short term) technology, and it is not the right long term technology either......Throughout the world, nations are seeking ways to decrease CO2 emissions and to reduce their dependency on fossil fuels, especially oil and gas deriving from so-called politically unstable regions. The efforts comprise the energy sector (heat and electricity) as well as the transport sector......, that biomass substitutes gas in the heat & power sector and gas substitute oil in the transport sector. By taking this path, we overall achieve almost twice as high a CO2 reduction and save almost twice as much oil, as if we want to substitute the oil via car engines through conversion to ethanol. We must...
NMNAT2:HSP90 Complex Mediates Proteostasis in Proteinopathies.
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Yousuf O Ali
Full Text Available Nicotinamide mononucleotide adenylyl transferase 2 (NMNAT2 is neuroprotective in numerous preclinical models of neurodegeneration. Here, we show that brain nmnat2 mRNA levels correlate positively with global cognitive function and negatively with AD pathology. In AD brains, NMNAT2 mRNA and protein levels are reduced. NMNAT2 shifts its solubility and colocalizes with aggregated Tau in AD brains, similar to chaperones, which aid in the clearance or refolding of misfolded proteins. Investigating the mechanism of this observation, we discover a novel chaperone function of NMNAT2, independent from its enzymatic activity. NMNAT2 complexes with heat shock protein 90 (HSP90 to refold aggregated protein substrates. NMNAT2's refoldase activity requires a unique C-terminal ATP site, activated in the presence of HSP90. Furthermore, deleting NMNAT2 function increases the vulnerability of cortical neurons to proteotoxic stress and excitotoxicity. Interestingly, NMNAT2 acts as a chaperone to reduce proteotoxic stress, while its enzymatic activity protects neurons from excitotoxicity. Taken together, our data indicate that NMNAT2 exerts its chaperone or enzymatic function in a context-dependent manner to maintain neuronal health.
Expression analysis of HSP70 in the testis of Octopus tankahkeei under thermal stress.
Long, Ling-Li; Han, Ying-Li; Sheng, Zhang; Du, Chen; Wang, You-Fa; Zhu, Jun-Quan
The gene encoding heat shock protein 70 (HSP70) was identified in Octopus tankahkeei by homologous cloning and rapid amplification of cDNA ends (RACE). The full-length cDNA (2471 bp) consists of a 5'-untranslated region (UTR) (89 bp), a 3'-UTR (426 bp), and an open reading frame (1956 bp) that encodes 651 amino acid residues with a predicted molecular mass of 71.8 kDa and an isoelectric point of 5.34. Based on the amino acid sequence analysis and multiple sequence alignment, this cDNA is a member of cytoplasmic hsp70 subfamily of the hsp70 family and was designated as ot-hsp70. Tissue expression analysis showed that HSP70 expression is highest in the testes when all examined organs were compared. Immunohistochemistry analysis, together with hematoxylin-eosin staining, revealed that the HSP70 protein was expressed in all spermatogenic cells, but not in fibroblasts. In addition, O. tankahkeei were heat challenged by exposure to 32 °C seawater for 2 h, then returned to 13 °C for various recovery time (0-24 h). Relative expression of ot-hsp70 mRNA in the testes was measured at different time points post-challenge by quantitative real-time PCR. A clear time-dependent mRNA expression of ot-hsp70 after thermal stress indicates that the HSP70 gene is inducible. Ultrastructural changes of the heat-stressed testis were observed by transmission electron microscopy. We suggest that HSP70 plays an important role in spermatogenesis and testis protection against thermal stress in O. tankahkeei.
Compound A, a selective glucocorticoid receptor modulator, enhances heat shock protein Hsp70 gene promoter activation.
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Ilse M Beck
Full Text Available Compound A possesses glucocorticoid receptor (GR-dependent anti-inflammatory properties. Just like classical GR ligands, Compound A can repress NF-κB-mediated gene expression. However, the monomeric Compound A-activated GR is unable to trigger glucocorticoid response element-regulated gene expression. The heat shock response potently activates heat shock factor 1 (HSF1, upregulates Hsp70, a known GR chaperone, and also modulates various aspects of inflammation. We found that the selective GR modulator Compound A and heat shock trigger similar cellular effects in A549 lung epithelial cells. With regard to their anti-inflammatory mechanism, heat shock and Compound A are both able to reduce TNF-stimulated IκBα degradation and NF-κB p65 nuclear translocation. We established an interaction between Compound A-activated GR and Hsp70, but remarkably, although the presence of the Hsp70 chaperone as such appears pivotal for the Compound A-mediated inflammatory gene repression, subsequent novel Hsp70 protein synthesis is uncoupled from an observed CpdA-induced Hsp70 mRNA upregulation and hence obsolete in mediating CpdA's anti-inflammatory effect. The lack of a Compound A-induced increase in Hsp70 protein levels in A549 cells is not mediated by a rapid proteasomal degradation of Hsp70 or by a Compound A-induced general block on translation. Similar to heat shock, Compound A can upregulate transcription of Hsp70 genes in various cell lines and BALB/c mice. Interestingly, whereas Compound A-dependent Hsp70 promoter activation is GR-dependent but HSF1-independent, heat shock-induced Hsp70 expression alternatively occurs in a GR-independent and HSF1-dependent manner in A549 lung epithelial cells.
Administration of Mycobacterium leprae rHsp65 aggravates experimental autoimmune uveitis in mice.
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Eliana B Marengo
Full Text Available The 60 kDa heat shock protein family, Hsp60, constitutes an abundant and highly conserved class of molecules that are highly expressed in chronic-inflammatory and autoimmune processes. Experimental autoimmune uveitis [EAU] is a T cell mediated intraocular inflammatory disease that resembles human uveitis. Mycobacterial and homologous Hsp60 peptides induces uveitis in rats, however their participation in aggravating the disease is poorly known. We here evaluate the effects of the Mycobacterium leprae Hsp65 in the development/progression of EAU and the autoimmune response against the eye through the induction of the endogenous disequilibrium by enhancing the entropy of the immunobiological system with the addition of homologous Hsp. B10.RIII mice were immunized subcutaneously with interphotoreceptor retinoid-binding protein [IRBP], followed by intraperitoneally inoculation of M. leprae recombinant Hsp65 [rHsp65]. We evaluated the proliferative response, cytokine production and the percentage of CD4(+IL-17(+, CD4(+IFN-gamma(+ and CD4(+Foxp3(+ cells ex vivo, by flow cytometry. Disease severity was determined by eye histological examination and serum levels of anti-IRBP and anti-Hsp60/65 measured by ELISA. EAU scores increased in the Hsp65 group and were associated with an expansion of CD4(+IFN-gamma(+ and CD4(+IL-17(+ T cells, corroborating with higher levels of IFN-gamma. Our data indicate that rHsp65 is one of the managers with a significant impact over the immune response during autoimmunity, skewing it to a pathogenic state, promoting both Th1 and Th17 commitment. It seems comprehensible that the specificity and primary function of Hsp60 molecules can be considered as a potential pathogenic factor acting as a whistleblower announcing chronic-inflammatory diseases progression.
Differences in the curing of [PSI+] prion by various methods of Hsp104 inactivation.
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Yang-Nim Park
Full Text Available [PSI(+] yeast, containing the misfolded amyloid conformation of Sup35 prion, is cured by inactivation of Hsp104. There has been controversy as to whether inactivation of Hsp104 by guanidine treatment or by overexpression of the dominant negative Hsp104 mutant, Hsp104-2KT, cures [PSI(+] by the same mechanism- inhibition of the severing of the prion seeds. Using live cell imaging of Sup35-GFP, overexpression of Hsp104-2KT caused the foci to increase in size, then decrease in number, and finally disappear when the cells were cured, similar to that observed in cells cured by depletion of Hsp104. In contrast, guanidine initially caused an increase in foci size but then the foci disappeared before the cells were cured. By starving the yeast to make the foci visible in cells grown with guanidine, the number of cells with foci was found to correlate exactly with the number of [PSI(+] cells, regardless of the curing method. Therefore, the fluorescent foci are the prion seeds required for maintenance of [PSI(+] and inactivation of Hsp104 cures [PSI(+] by preventing severing of the prion seeds. During curing with guanidine, the reduction in seed size is an Hsp104-dependent effect that cannot be explained by limited severing of the seeds. Instead, in the presence of guanidine, Hsp104 retains an activity that trims or reduces the size of the prion seeds by releasing Sup35 molecules that are unable to form new prion seeds. This Hsp104 activity may also occur in propagating yeast.
Hsp105 family proteins suppress staurosporine-induced apoptosis by inhibiting the translocation of Bax to mitochondria in HeLa cells
International Nuclear Information System (INIS)
Hsp105 (Hsp105α and Hsp105β), major heat shock proteins in mammalian cells, belong to a subgroup of the HSP70 family, HSP105/110. Previously, we have shown that Hsp105α has completely different effects on stress-induced apoptosis depending on cell type. However, the molecular mechanisms by which Hsp105α regulates stress-induced apoptosis are not fully understood. Here, we established HeLa cells that overexpress either Hsp105α or Hsp105β by removing doxycycline and examined how Hsp105 modifies staurosporine (STS)-induced apoptosis in HeLa cells. Apoptotic features such as the externalization of phosphatidylserine on the plasma membrane and nuclear morphological changes were induced by the treatment with STS, and the STS-induced apoptosis was suppressed by overexpression of Hsp105α or Hsp105β. In addition, we found that overexpression of Hsp105α or Hsp105β suppressed the activation of caspase-3 and caspase-9 by preventing the release of cytochrome c from mitochondria. Furthermore, the translocation of Bax to mitochondria, which results in the release of cytochrome c from the mitochondria, was also suppressed by the overexpression of Hsp105α or Hsp105β. Thus, it is suggested that Hsp105 suppresses the stress-induced apoptosis at its initial step, the translocation of Bax to mitochondria in HeLa cells
International Nuclear Information System (INIS)
After having indicated the various possible origins of biomass, this paper considers the issue of bio-energies, i.e., energies produced with biomass related to forest or agriculture production. Some indicators are defined (share of renewable energies, share of biomass in the energy production and consumption, number of production units). Stake holders are identified. Then, major and emerging trends are identified and discussed. The major trends are: development and diversification of renewable energies, development of bio-fuels with the support of incentive policies, prevalence of the wood-energy sector on the whole renewable energies, increase of surfaces dedicated to bio-fuels since the end of the 1990's, a French biogas sector which is late with respect to other countries. The emerging trends are: the important role of oil price in the development of bio-fuels, a necessary public support for the development of biogas, mobilization of research and development of competitiveness poles for bio-industries. Some prospective issues are also discussed in terms of uncertainties (soil availabilities, environmental performance of bio-fuels, available biomass resource, need of a technological advance, and evolution of energy needs on a medium term, tax and public policy). Three hypotheses of bio-energy evolutions are discussed
Bio diesel production from algae
International Nuclear Information System (INIS)
Algae appear to be an emerging source of biomass for bio diesel that has the potential to completely displace fossil fuel. Two thirds of earth's surface is covered with water, thus alga e would truly be renewable option of great potential for global energy needs. This study discusses specific and comparative bio diesel quantitative potential of Cladophora sp., also highlighting its biomass (after oil extraction), pH and sediments (glycerine, water and pigments) quantitative properties. Comparison of Cladophora sp., with Oedogonium sp., and Spirogyra sp., (Hossain et al., 2008) shows that Cladophora sp., produce higher quantity of bio diesel than Spirogyra sp., whereas biomass and sediments were higher than the both algal specimens in comparison to the results obtained by earlier workers. No prominent difference in pH of bio diesel was found. In Pakistan this is a first step towards bio diesel production from algae. Results indicate that Cladophora sp., provide a reasonable quantity of bio diesel, its greater biomass after oil extraction and sediments make it a better option for bio diesel production than the comparing species. (author)
Jones, Julian
This new work is dedicated to glasses and their variants which can be used as biomaterials to repair diseased and damaged tissues. Bio-glasses are superior to other biomaterials in many applications, such as healing bone by signaling stem cells to become bone cells. Key features: First book on biomaterials to focus on bio-glassesEdited by a leading authority on bio-glasses trained by one of its inventors, Dr Larry HenchSupported by the International Commission on Glass (ICG)Authored by members of the ICG Biomedical Glass Committee, with the goal of creating a seamless textb
Mapping the Hsp90 Genetic Network Reveals Ergosterol Biosynthesis and Phosphatidylinositol-4-Kinase Signaling as Core Circuitry Governing Cellular Stress
O'Meara, Teresa R.; Valaei, Seyedeh Fereshteh; Diezmann, Stephanie; Cowen, Leah E.
Candida albicans is a leading human fungal pathogen that causes life-threatening systemic infections. A key regulator of C. albicans stress response, drug resistance, morphogenesis, and virulence is the molecular chaperone Hsp90. Targeting Hsp90 provides a powerful strategy to treat fungal infections, however, the therapeutic utility of current inhibitors is compromised by toxicity due to inhibition of host Hsp90. To identify components of the Hsp90-dependent circuitry governing virulence and drug resistance that are sufficiently divergent for selective targeting in the pathogen, we pioneered chemical genomic profiling of the Hsp90 genetic network in C. albicans. Here, we screen mutant collections covering ~10% of the genome for hypersensitivity to Hsp90 inhibition in multiple environmental conditions. We identify 158 HSP90 chemical genetic interactors, most of which are important for growth only in specific environments. We discovered that the sterol C-22 desaturase gene ERG5 and the phosphatidylinositol-4-kinase (PI4K) gene STT4 are HSP90 genetic interactors under multiple conditions, suggesting a function upstream of Hsp90. By systematic analysis of the ergosterol biosynthetic cascade, we demonstrate that defects in ergosterol biosynthesis induce cellular stress that overwhelms Hsp90's functional capacity. By analysis of the phosphatidylinositol pathway, we demonstrate that there is a genetic interaction between the PI4K Stt4 and Hsp90. We also establish that Stt4 is required for normal actin polarization through regulation of Wal1, and suggest a model in which defects in actin remodeling induces stress that creates a cellular demand for Hsp90 that exceeds its functional capacity. Consistent with this model, actin inhibitors are synergistic with Hsp90 inhibitors. We highlight new connections between Hsp90 and virulence traits, demonstrating that Erg5 and Stt4 enable activation of macrophage pyroptosis. This work uncovers novel circuitry regulating Hsp90
Interaction of the Hsp90 cochaperone cyclophilin 40 with Hsc70.
Carrello, Amerigo; Allan, Rudi K; Morgan, Sarah L; Owen, Barbara A L; Mok, Danny; Ward, Bryan K; Minchin, Rodney F; Toft, David O; Ratajczak, Thomas
The high-affinity ligand-binding form of unactivated steroid receptors exists as a multicomponent complex that includes heat shock protein (Hsp)90; one of the immunophilins cyclophilin 40 (CyP40), FKBP51, or FKBP52; and an additional p23 protein component. Assembly of this heterocomplex is mediated by Hsp70 in association with accessory chaperones Hsp40, Hip, and Hop. A conserved structural element incorporating a tetratricopeptide repeat (TPR) domain mediates the interaction of the immunophilins with Hsp90 by accommodating the C-terminal EEVD peptide of the chaperone through a network of electrostatic and hydrophobic interactions. TPR cochaperones recognize the EEVD structural motif common to both Hsp90 and Hsp70 through a highly conserved clamp domain. In the present study, we investigated in vitro the molecular interactions between CyP40 and FKBP52 and other stress-related components involved in steroid receptor assembly, namely Hsp70 and Hop. Using a binding protein-retention assay with CyP40 fused to glutathione S-transferase immobilized on glutathione-agarose, we have identified the constitutively expressed form of Hsp70, heat shock cognate (Hsc)70, as an additional target for CyP40. Deletion mapping studies showed the binding determinants to be similar to those for CyP40-Hsp90 interaction. Furthermore, a mutational analysis of CyP40 clamp domain residues confirmed the importance of this motif in CyP40-Hsc70 interaction. Additional residues thought to mediate binding specificity through hydrophobic interactions were also important for Hsc70 recognition. CyP40 was shown to have a preference for Hsp90 over Hsc70. Surprisingly, FKBP52 was unable to compete with CyP40 for Hsc70 binding, suggesting that FKBP52 discriminates between the TPR cochaperone-binding sites in Hsp90 and Hsp70. Hop, which contains multiple units of the TPR motif, was shown to be a direct competitor with CyP40 for Hsc70 binding. Similar to Hop, CyP40 was shown not to influence the adenosine
Navigating the Bio-Politics of Childhood
Lee, Nick; Motzkau, Johanna
Childhood research has long shared a bio-political terrain with state agencies in which children figure primarily as "human futures". In the 20th century bio-social dualism helped to make that terrain navigable by researchers, but, as life processes increasingly become key sites of bio-political action, bio-social dualism is becoming less useful…
Growth of cerium oxide thin layers for the manufacture of dosemeters and/or irradiation detectors by magnetron RF cathodic sputtering
International Nuclear Information System (INIS)
Oxide thin films deposited on silicon substrate are interesting for the manufacture of dosemeters and detectors of gas, humidity, temperature and irradiation. The irradiation dose measurement is required for assessing the risks and advantages of the use of ionizing radiations in fields such as biology, medicine and more generally in all the civil and military nuclear applications. According to literature, cerium oxide seems to be potentially interesting for the manufacture of dosemeters and/or irradiation detectors. The influence of the deposition parameters, such as the inter-electrodes distance, the temperature, the RF power, the work pressure, on the crystalline quality of the CeO2 layers deposited on a silicon (111) substrate by magnetron RF cathodic sputtering has been studied. All these thin films have been characterized by X-ray diffraction and by Raman spectroscopy. At the present time, studies are carried out on 'flash' annealing in order to improve the crystalline state of the thin layers. The aim is to study the influence of gamma and neutrons irradiations on the electric properties of capacities made of CeO2 thin films. (O.M.)
Analysis of neutron and photon response of a TLD-ALBEDO personal dosemeter on an ISO slab phantom using TRIPOLI-4.3 Monte Carlo code.
Lee, Y K
TRIPOLI-4.3 Monte Carlo transport code has been used to evaluate the QUADOS (Quality Assurance of Computational Tools for Dosimetry) problem P4, neutron and photon response of an albedo-type thermoluminescence personal dosemeter (TLD) located on an ISO slab phantom. Two enriched 6LiF and two 7LiF TLD chips were used and they were protected, in front or behind, with a boron-loaded dosemeter-holder. Neutron response of the four chips was determined by counting 6Li(n,t)4He events using ENDF/B-VI.4 library and photon response by estimating absorbed dose (MeV g(-1)). Ten neutron energies from thermal to 20 MeV and six photon energies from 33 keV to 1.25 MeV were used to study the energy dependence. The fraction of the neutron and photon response owing to phantom backscatter has also been investigated. Detailed TRIPOLI-4.3 solutions are presented and compared with MCNP-4C calculations. PMID:16381740
Phosphorylation of an envelope-associated Hsp70 homolog in amyloplasts isolated from cultured cells of sycamore (Acer pseudoplatanus L.).
Checa, S K; Viale, A M
The presence of Hsp70 and Hsp60 molecular chaperones in amyloplasts isolated from cultured sycamore cells was analyzed by immunoblotting. Hsp70 homologs were located in both amyloplast envelope and stromal fractions, but no Hsp60 homologs were detected in any of the different suborganellar fractions. Incubation of whole amyloplasts or their envelope fraction with Mg2+ gamma-32P-ATP resulted in a rapid phosphorylation of the envelope-associated Hsp70 homolog, which constitutes a major target of phosphorylation in these plastids.
2010 World bio-energy conference
International Nuclear Information System (INIS)
After having evoked the bio-energy price awarded to a Brazilian for his works on the use of eucalyptus as energy source, this report proposes a synthesis of the highlights of the conference: discussions about sustainability, bio-energies as an opportunity for developing countries, the success of bio-energies in Sweden, and more particularly some technological advances in the field of biofuels: a bio-LPG by Biofuel-solution AB, catalysis, bio-diesel from different products in a Swedish farm, a second generation ethanol by the Danish company Inbicon, a large scale methanization in Goteborg, a bio-refinery concept in Sweden, bio-gases
Client Proteins and Small Molecule Inhibitors Display Distinct Binding Preferences for Constitutive and Stress-Induced HSP90 Isoforms and Their Conformationally Restricted Mutants.
Directory of Open Access Journals (Sweden)
Thomas L Prince
Full Text Available The two cytosolic/nuclear isoforms of the molecular chaperone HSP90, stress-inducible HSP90α and constitutively expressed HSP90β, fold, assemble and maintain the three-dimensional structure of numerous client proteins. Because many HSP90 clients are important in cancer, several HSP90 inhibitors have been evaluated in the clinic. However, little is known concerning possible unique isoform or conformational preferences of either individual HSP90 clients or inhibitors. In this report, we compare the relative interaction strength of both HSP90α and HSP90β with the transcription factors HSF1 and HIF1α, the kinases ERBB2 and MET, the E3-ubiquitin ligases KEAP1 and RHOBTB2, and the HSP90 inhibitors geldanamycin and ganetespib. We observed unexpected differences in relative client and drug preferences for the two HSP90 isoforms, with HSP90α binding each client protein with greater apparent affinity compared to HSP90β, while HSP90β bound each inhibitor with greater relative interaction strength compared to HSP90α. Stable HSP90 interaction was associated with reduced client activity. Using a defined set of HSP90 conformational mutants, we found that some clients interact strongly with a single, ATP-stabilized HSP90 conformation, only transiently populated during the dynamic HSP90 chaperone cycle, while other clients interact equally with multiple HSP90 conformations. These data suggest different functional requirements among HSP90 clientele that, for some clients, are likely to be ATP-independent. Lastly, the two inhibitors examined, although sharing the same binding site, were differentially able to access distinct HSP90 conformational states.
Research Advances of HSP27's Role in Cardiovascular Diseases%HSP27在心血管疾病中作用的研究进展
Institute of Scientific and Technical Information of China (English)
热休克蛋白27(HSP27)是小分子HSP家族中的重要成员,细胞在外界自由基、热、缺血和毒性物质等刺激下可诱导其产生,在各种肿瘤和正常组织中特别是心脏组织中呈高表达.在对抗细心肌凋亡、抗缺血损伤、抗炎性反应中HSP27都有着积极的作用,对血管平滑肌细胞的增殖、迁移和动脉粥样硬化的发生和发展过程都有调控作用.HSP27可能成为治疗心血管疾病的新途径.%HSP27 is an important member of small molecular weight heat shock protein( HSP ) family, the external stimulation of free radicals, heat, ischemic and toxic substances can induce the generation of HSP27 in the cell, presenting high expression in a variety of tumors and normal tissues, with especially high expression in cardiac tissue, which have a positive effect in the anti-apoptosis, anti-ischemia injury and anti-inflammatory. It has a regulatory role in the vascular smooth muscle cell proliferation and migration and the occurrence and development of atherosclerosis. HSP27 may be a new therapeutic strategy of cardiovascular diseases.
Induction of hsp60 in the rotifer, Brachionus plicatilis exposed to dispersed and undispersed crude oil
Energy Technology Data Exchange (ETDEWEB)
Wheelock, C.; Tjeerdema, R.; Wolfe, M. [Univ. of California, Santa Cruz, CA (United States). Dept. of Chemistry and Biochemistry
The use of chemical dispersants to treat oil spills remains a controversial area. Questions arise as to whether the dispersed oil is in fact more toxic than the original spill, potentially increasing the exposure of organisms in the water column to the dispersed components. Stress proteins, including hsp60, are a group of highly conserved proteins that are induced in response to a wide variety of environmental agents, including UV light, heavy metals, and xenobiotics. They are constitutively expressed, but Brachionus plicatilis has been used to document increased hsp60 levels in response to different environmental stresses. Hsp60 was therefore selected as a sublethal endpoint for B. plicatilis exposed to a range of concentrations of a water accommodated fraction (WAF) of Prudhoe Bay Crude Oil (PBCO), a PCBO/dispersant (Corexit 9527) fraction and a mixture of Corexit 9527 alone. All exposures were done at concentrations below the no observable effect level (NOEL) and at two different salinities, 22 ppt and 34 ppt. Laemmli SDS-PAGE techniques followed by Western Blotting using hsp60 specific antibodies and chemiluminescent detection were used to isolate, identify and measure induced hsp60 as a percentage of control values. Hsp60 induction exhibited a biphasic response with maximal induction occurring at lower concentrations of all three different mixtures, WAF, PBCO/Corexit 9527, and Corexit 9527 alone. Preliminary data found that the dispersed oil is indeed more toxic in terms of hsp60 induction than both the undispersed oil and the dispersing agent alone.
HSF1-TPR interaction facilitates export of stress-induced HSP70 mRNA.
Skaggs, Hollie S; Xing, Hongyan; Wilkerson, Donald C; Murphy, Lynea A; Hong, Yiling; Mayhew, Christopher N; Sarge, Kevin D
Stress conditions inhibit mRNA export, but mRNAs encoding heat shock proteins continue to be efficiently exported from the nucleus during stress. How HSP mRNAs bypass this stress-associated export inhibition was not known. Here, we show that HSF1, the transcription factor that binds HSP promoters after stress to induce their transcription, interacts with the nuclear pore-associating TPR protein in a stress-responsive manner. TPR is brought into proximity of the HSP70 promoter after stress and preferentially associates with mRNAs transcribed from this promoter. Disruption of the HSF1-TPR interaction inhibits the export of mRNAs expressed from the HSP70 promoter, both endogenous HSP70 mRNA and a luciferase reporter mRNA. These results suggest that HSP mRNA export escapes stress inhibition via HSF1-mediated recruitment of the nuclear pore-associating protein TPR to HSP genes, thereby functionally connecting the first and last nuclear steps of the gene expression pathway, transcription and mRNA export.
Conformational diversity in the TPR domain-mediated interaction of protein phosphatase 5 with Hsp90.
Cliff, Matthew J; Harris, Richard; Barford, David; Ladbury, John E; Williams, Mark A
Protein phosphatase 5 (Ppp5) is one of several proteins that bind to the Hsp90 chaperone via a tetratricopeptide repeat (TPR) domain. We report the solution structure of a complex of the TPR domain of Ppp5 with the C-terminal pentapeptide of Hsp90. This structure has the "two-carboxylate clamp" mechanism of peptide binding first seen in the Hop-TPR domain complexes with Hsp90 and Hsp70 peptides. However, NMR data reveal that the Ppp5 clamp is highly dynamic, and that there are multiple modes of peptide binding and mobility throughout the complex. Although this interaction is of very high affinity, relatively few persistent contacts are found between the peptide and the Ppp5-TPR domain, thus explaining its promiscuity in binding both Hsp70 and Hsp90 in vivo. We consider the possible implications of this dynamic structure for the mechanism of relief of autoinhibition in Ppp5 and for the mechanisms of TPR-mediated recognition of Hsp90 by other proteins.
Stress-induced interaction between p38 MAPK and HSP70
International Nuclear Information System (INIS)
Highlights: ► HSP70 interacts to p38 MAPK in vitro and in vivo. ► HSP70 co-localizes with p38 MAPK in the nucleus upon stress. ► HSP70 is involved in the nuclear phosphorylation of MK2 by p38 MAPK. -- Abstract: p38 MAPK, one of the four MAPK subfamilies in mammalian cells, is activated by environmental stresses and pro-inflammatory cytokines, playing fundamental roles in many biological processes. Despite all that is known on the structure and functions of p38, many questions still exist. The coupling of activation and nuclear translocation represents an important aspect of p38 signaling. In our effort in exploring the potential chaperone for p38 translocation, we performed an endogenous pull-down assay and identified HSP70 as a potential interacting protein of p38. We confirmed the interaction between p38 and HSP70 in vitro and in vivo, and identified their interaction domains. We also showed stress-induced nuclear co-localization of these two proteins. Our preliminary result indicated that HSP70 was related to the phosphorylation of MK2, a specific nuclear downstream target of p38, suggesting HSP70 is a potential chaperone for the nuclear translocation of p38.
Expression analysis of NOS family and HSP genes during thermal stress in goat (Capra hircus).
Yadav, Vijay Pratap; Dangi, Satyaveer Singh; Chouhan, Vikrant Singh; Gupta, Mahesh; Dangi, Saroj K; Singh, Gyanendra; Maurya, Vijay Prakash; Kumar, Puneet; Sarkar, Mihir
Approximately 50 genes other than heat shock protein (HSP) expression changes during thermal stress. These genes like nitric oxide synthase (NOS) need proper attention and investigation to find out their possible role in the adaptation to thermal stress in animals. So, the present study was undertaken to demonstrate the expressions of inducible form type II NOS (iNOS), endothelial type III NOS (eNOS), constitutively expressed enzyme NOS (cNOS), HSP70, and HSP90 in peripheral blood mononuclear cells (PBMCs) during different seasons in Barbari goats. Real-time polymerase chain reaction, western blot, and immunocytochemistry were applied to investigate messenger RNA (mRNA) expression, protein expression, and immunolocalization of examined factors. The mRNA and protein expressions of iNOS, eNOS, cNOS, HSP70, and HSP90 were significantly higher (P P < 0.05) during peak winter season as compared with moderate season. The iNOS, eNOS, cNOS, HSP70, and HSP90 were mainly localized in plasma membrane and cytoplasm of PBMCs. To conclude, data generated in the present study indicate the possible involvement of the NOS family genes in amelioration of thermal stress so as to maintain cellular integrity and homeostasis in goats. PMID:26205811
Molecular cloning of HSP70 in Mycoplasma ovipneumoniae and comparison with that of other mycoplasmas.
Li, M; Ma, C J; Liu, X M; Zhao, D; Xu, Q C; Wang, Y J
Mycoplasma ovipneumoniae, a bacterial species that specifically affects ovine and goat, is the cause of ovine infectious pleuropneumonia. We cloned, sequenced and analyzed heat shock protein 70 (HSP70) (dnaK) gene of M. ovipneumoniae. The full length open reading frame of the M. ovipneumoniae HSP70 gene consists of 1812 nucleotides, with a G+C content of 34.16%, encoding 604 amino acids. Comparative analysis with the HSP70 sequences of 15 Mycoplasma species revealed 59 to 87% DNA sequence identity, with an amino acid sequence identity range of 58 to 94%. M. ovipneumoniae and M. hyopneumoniae shared the highest DNA and amino acid sequence identity (87 and 94%, respectively). Based on phylogenetic analysis, both the DNA and amino acid identities of M. ovipneumoniae with other mycoplasmal HSP70 were correlated with the degree of relationship between the species. The C-terminus of the HSP70 was cloned into a bacterial expression vector and expressed in Escherichia coli cells. The recombinant C-terminal portion of HSP70 protein strongly reacted with convalescent sera from M. ovipneumoniae-infected sheep, based on an immunoblotting assay. This indicates that HSP70 is immunogenic in a natural M. ovipneumoniae infection and may be a relevant antigen for vaccine development.
Increased Levels of IgG Antibodies against Human HSP60 in Patients with Spondyloarthritis
DEFF Research Database (Denmark)
Nielsen, Astrid Hjelholt; Carlsen, Thomas; Deleuran, Bent;
Introduction: Spondyloarthritis (SpA) comprises a heterogeneous group of inflammatory diseases, with strong association to human leukocyte antigen (HLA)-B27. SpA is suggested triggered by bacterial infection, and bacterial heat shock protein (HSP) seems to be a strong T cell antigen. Since...... severity in relation to HLA-B27 was evaluated. Material & Methods: Serum samples from 82 patients and 50 controls were analysed by enzyme-linked immunosorbent assay (ELISA) for immunoglobulin (Ig)G1, IgG2, IgG3 and IgG4 antibodies against human HSP60 and HSP60 from Chlamydia trachomatis, Salmonella...... against human HSP60, but not antibodies against bacterial HSP60, were elevated in the SpA group compared with the control group. Association between IgG3 antibodies against human HSP60 and BASMI was shown in HLA-B27+ patients. Only weak correlation between antibodies against bacterial and human HSP60 was...
Identification and characterization of the GhHsp20 gene family in Gossypium hirsutum.
Ma, Wei; Zhao, Ting; Li, Jie; Liu, Bingliang; Fang, Lei; Hu, Yan; Zhang, Tianzhen
In higher plants, Heat Shock Protein 20 (Hsp20) plays crucial roles in growth, development and responses to abiotic stresses. In this study, 94 GhHsp20 genes were identified in G. hirsutum, and these genes were phylogenetically clustered into 14 subfamilies. Out of these, 73 paralogous gene pairs remained in conserved positions on segmental duplicated blocks and only 14 genes clustered into seven tandem duplication event regions. Transcriptome analysis showed that 82 GhHsp20 genes were expressed in at least one tested tissues, indicating that the GhHsp20 genes were involved in physiological and developmental processes of cotton. Further, expression profiles under abiotic stress exhibited that two-thirds of the GhHsp20 genes were responsive to heat stress, while 15 genes were induced by multiple stresses. In addition, qRT-PCR confirmed that 16 GhHsp20 genes were hot-induced, and eight genes were up-regulated under multiple abiotic stresses and stress-related phytohormone treatments. Taken together, our results presented here would be helpful in laying the foundation for understanding the complex mechanisms of GhHsp20 mediated developmental processes and abiotic stress signaling transduction pathways in cotton. PMID:27580529
The Hsp110 molecular chaperone stabilizes apolipoprotein B from endoplasmic reticulum-associated degradation (ERAD).
Hrizo, Stacy L; Gusarova, Viktoria; Habiel, David M; Goeckeler, Jennifer L; Fisher, Edward A; Brodsky, Jeffrey L
Apolipoprotein B (apoB) is the most abundant protein in low density lipoproteins and plays key roles in cholesterol homeostasis. The co-translational degradation of apoB is controlled by fatty acid levels in the endoplasmic reticulum (ER) and is mediated by the proteasome. To define the mechanism of apoB degradation, we employed a cell-free system in which proteasome-dependent degradation is recapitulated with yeast cytosol, and we developed an apoB yeast expression system. We discovered that a yeast Hsp110, Sse1p, associates with and stabilizes apoB, which contrasts with data indicating that select Hsp70s and Hsp90s facilitate apoB degradation. However, the Ssb Hsp70 chaperones have no effect on apoB turnover. To determine whether our results are relevant in mammalian cells, Hsp110 was overexpressed in hepatocytes, and enhanced apoB secretion was observed. This study indicates that chaperones within distinct complexes can play unique roles during ER-associated degradation (ERAD), establishes a role for Sse1/Hsp110 in ERAD, and identifies Hsp110 as a target to lower cholesterol. PMID:17823116
Expression analysis of NOS family and HSP genes during thermal stress in goat ( Capra hircus)
Yadav, Vijay Pratap; Dangi, Satyaveer Singh; Chouhan, Vikrant Singh; Gupta, Mahesh; Dangi, Saroj K.; Singh, Gyanendra; Maurya, Vijay Prakash; Kumar, Puneet; Sarkar, Mihir
Approximately 50 genes other than heat shock protein (HSP) expression changes during thermal stress. These genes like nitric oxide synthase (NOS) need proper attention and investigation to find out their possible role in the adaptation to thermal stress in animals. So, the present study was undertaken to demonstrate the expressions of inducible form type II NOS (iNOS), endothelial type III NOS (eNOS), constitutively expressed enzyme NOS (cNOS), HSP70, and HSP90 in peripheral blood mononuclear cells (PBMCs) during different seasons in Barbari goats. Real-time polymerase chain reaction, western blot, and immunocytochemistry were applied to investigate messenger RNA (mRNA) expression, protein expression, and immunolocalization of examined factors. The mRNA and protein expressions of iNOS, eNOS, cNOS, HSP70, and HSP90 were significantly higher ( P < 0.05) during peak summer, and iNOS and eNOS expressions were also observed to be significantly higher ( P < 0.05) during peak winter season as compared with moderate season. The iNOS, eNOS, cNOS, HSP70, and HSP90 were mainly localized in plasma membrane and cytoplasm of PBMCs. To conclude, data generated in the present study indicate the possible involvement of the NOS family genes in amelioration of thermal stress so as to maintain cellular integrity and homeostasis in goats.
Cell-surface expression of Hsp70 on hematopoietic cancer cells after inhibition of HDAC activity
DEFF Research Database (Denmark)
Jensen, Helle
The function of Hsp70 depends on its cellular location: When located intracellularly it exerts cytoprotective and anti-apoptotic functions, whereas it exerts immunostimulatory functions when located extracellularly. Secreted Hsp70 is for example involved in cross-presentation of cancer-derived an......The function of Hsp70 depends on its cellular location: When located intracellularly it exerts cytoprotective and anti-apoptotic functions, whereas it exerts immunostimulatory functions when located extracellularly. Secreted Hsp70 is for example involved in cross-presentation of cancer......-derived antigenic peptides, a function which is currently explored in immunotherapeutic approaches against cancer. Additionally, membrane-bound Hsp70 can stimulate antigen presenting cells to release proinflammatory cytokines and can provide a target structure for NK cell-mediated lysis. Human cancer cells...... frequently express Hsp70 on their cell surface, whereas the corresponding normal tissues do not. In addition, several clinically applied reagents, such as alkyl-lysophospholipides, chemotherapeutic agents, and anti-inflammatory reagents, have been found to enhance Hsp70 cell surface expression on cancer...
ClpB/Hsp100 proteins and heat stress tolerance in plants.
Mishra, Ratnesh Chandra; Grover, Anil
High-temperature stress can disrupt cellular proteostasis, resulting in the accumulation of insoluble protein aggregates. For survival under stressful conditions, it is important for cells to maintain a pool of native soluble proteins by preventing and/or dissociating these aggregates. Chaperones such as GroEL/GroES (Hsp60/Hsp10) and DnaK/DnaJ/GrpE (Hsp70/Hsp40/nucleotide exchange factor) help cells minimize protein aggregation. Protein disaggregation is accomplished by chaperones belonging to the Caseinolytic Protease (Clp) family of proteins. ClpB/Hsp100 proteins are strikingly ubiquitous and are found in bacteria, yeast and multi-cellular plants. The expression of these proteins is regulated by heat stress (HS) and developmental cues. Bacteria and yeast contain one and two forms of ClpB proteins, respectively. Plants possess multiple forms of these proteins that are localized to different cellular compartments (i.e. cytoplasm/nucleus, chloroplast or mitochondria). Overwhelming evidence suggests that ClpB/Hsp100 proteins play decisive roles in cell adaptation to HS. Mutant bacteria and yeast cells lacking active ClpB/Hsp100 proteins are critically sensitive to high-temperature stress. Likewise, Arabidopsis, maize and rice mutants lacking cytoplasmic ClpB proteins are very sensitive to heat. In this study, we present the structural and functional attributes of plant ClpB forms. PMID:26121931
A mathematical model of the hsp70 regulation in the cell.
Peper, A; Grimbergen, C A; Spaan, J A; Souren, J E; van Wijk, R
A mathematical model of the regulation process of the heat shock protein hsp70 in the cell is presented. The model describes the damaging effect of elevated temperature on proteins; the interaction of free hsp70 with injured proteins and its chaperone role in nascent protein translation; the relation between the amount of free hsp70 and the formation of the activated trimer form of the heat shock factor protein (HSF); the binding of activated HSF with the heat shock elements on the DNA; the transcription of mRNA of hsp70 and the synthesis of hsp70. The reaction of the model to a temporal rise in temperature shows an initial decline and a subsequent sharp rise to an ultimately increased level of free hsp70 in the cell. The response of the model to both a single and two consecutive heat shocks appears to closely resemble experimental data on hsp70 synthesis. This general agreement demonstrates the structure of the model to be sound and suitable as a basis for further modelling the complex tolerance mechanism of the cell. PMID:9483450
Complexity of rice Hsp100 gene family: lessons from rice genome sequence data
Indian Academy of Sciences (India)
Gaurav Batra; Vineeta Singh Chauhan; Amanjot Singh; Neelam K Sarkar; Anil Grover
Elucidation of genome sequence provides an excellent platform to understand detailed complexity of the various gene families. Hsp100 is an important family of chaperones in diverse living systems. There are eight putative gene loci encoding for Hsp100 proteins in Arabidopsis genome. In rice, two full-length Hsp100 cDNAs have been isolated and sequenced so far. Analysis of rice genomic sequence by in silico approach showed that two isolated rice Hsp100 cDNAs correspond to Os05g44340 and Os02g32520 genes in the rice genome database. There appears to be three additional proteins (encoded by Os03g31300, Os04g32560 and Os04g33210 gene loci) that are variably homologous to Os05g44340 and Os02g32520 throughout the entire amino acid sequence. The above five rice Hsp100 genes show significant similarities in the signature sequences known to be conserved among Hsp100 proteins. While Os05g44340 encodes cytoplasmic Hsp100 protein, those encoded by the other four genes are predicted to have chloroplast transit peptides.
Molecular cloning of heat shock protein 10 (Hsp10) and 60 (Hsp60) cDNAs and their expression analysis under thermal stress in the sea cucumber Apostichopus japonicus.
Xu, Dongxue; Sun, Lina; Liu, Shilin; Zhang, Libin; Ru, Xiaoshang; Zhao, Ye; Yang, Hongsheng
Hsp10 and Hsp60 are important heat shock proteins (HSPs), which might be indispensable in the heat shock response and many other physiological processes. We obtained full-length cDNAs of genes hsp10 and hsp60 and classified their mRNA expression levels under thermal stress in the sea cucumber Apostichopus japonicus. Full-length hsp10 cDNA was 1528 bp containing a 5' untranslated region (UTR) of 83 bp, a 3' UTR of 1133 bp and an open reading frame (ORF) of 312 bp encoding 103 amino acid residues. Full-length hsp60 cDNA was 2560 bp containing a 118-bp 5' UTR, a 678-bp 3' UTR and a 1764-bp ORF encoding 586 amino acid residues. The deduced amino acid sequences of Hsp10 and Hsp60 shared the highest identity with sequences of the sea urchin Strongylocentrotus purpuratus, and phylogenetic trees showed that the evolution of Hsp10 and Hsp60 was almost in accord with the evolution of species. Further analysis by real-time PCR showed that the expression of hsp10 and hsp60 mRNA was highly up-regulated at 26 °C compared with other three groups (20, 22, 24 °C), and their expression in the intestine was in a time-dependent manner at 26 °C. The results suggested that hsp10 and hsp60 were involved in the heat-shock response in the sea cucumber A. japonicus. PMID:24721556
Hole, Torstein Nielsen; Jeno, Lucas Matias; Holtermann, Kristin; Raaheim, Arild; Velle, Gaute; Simonelli, Anne Laure; Vandvik, Vigdis
The bioCEED Survey 2015 is a baseline study of major tertiary-level biology education in Norway. The survey addresses themes such as learning in practice, transferable skills, motivation, laboratory and field learning, didactical approaches specifically relevant to biology education, knowledge needs and experiences of biologists in the workforce. The bioCEED Survey 2015 reports the results from four separate sub-surveys of tertiary-level biology education, mapping the experiences, attitu...
Institute of Scientific and Technical Information of China (English)
Yan Yongnian; Wang Xiaohong; Xiong Zhuo; Liu Haixia; Li Shengjie
In this paper we made a thorough and systematic expatiation of the definition, connotation and composition of bio-manufacture. Based on the different development stages and process of bioengineering, its main research direction and corresponding researches were reviewed. Furthermore, from the viewpoint of disciplinary crossing, integration and development, the main technological development direction of bio-engineering in the coming years was pointed out.
Glutamine May Repress the Weak LPS and Enhance the Strong Heat Shock Induction of Monocyte and Lymphocyte HSP72 Proteins but May Not Modulate the HSP72 mRNA in Patients with Sepsis or Trauma
Directory of Open Access Journals (Sweden)
Efrossini Briassouli
Full Text Available Objective. We assessed the lipopolysaccharide (LPS or heat shock (HS induction of heat shock protein-72 (HSP72 in peripheral blood mononuclear cells (PBMCs of patients with severe sepsis (SS or trauma-related systemic inflammatory response syndrome (SIRS, compared to healthy individuals (H; we also investigated any pre- or posttreatment modulating glutamine (Gln effect. Methods. SS (11, SIRS (10, and H (19 PBMCs were incubated with 1 μg/mL LPS or 43°HS. Gln 10 mM was either added 1 h before or 1 h after induction or was not added at all. We measured monocyte (m, lymphocyte (l, mRNA HSP72, HSP72 polymorphisms, interleukins (ILs, monocyte chemoattractant protein-1 (MCP-1, and cortisol levels. Results. Baseline lHSP72 was higher in SS p<0.03, and mHSP72 in SIRS p<0.02, compared to H. Only HS induced l/mHSP72/mRNA HSP72; LPS induced IL-6, IL-8, IL-10, and MCP-1. Induced mRNA was related to l/mHSP72, and was related negatively to cytokines. Intracellular l/mHSP72/HSP72 mRNA was related to serum ILs, not being influenced by cortisol, illness severity, and HSP72 polymorphisms. Gln did not induce mRNA in any group but modified l/mHSP72 after LPS/HS induction unpredictably. Conclusions. HSP72 mRNA and l/mHSP72 are higher among critically ill patients, further induced by HS, not by LPS. HSP72 proteins and HSP72 mRNA are related to serum ILs and are negatively related to supernatant cytokines, not being influenced by HSP72 polymorphisms, cortisol, or illness severity. Gln may depress l/mHSP72 after LPS exposure and enhance them after HS induction, but it may not affect early induced HSP72 mRNA.
Hsp60 is targeted to a cryptic mitochondrion-derived organelle ("crypton") in the microaerophilic protozoan parasite Entamoeba histolytica.
Mai, Z; Ghosh, S; Frisardi, M; Rosenthal, B; Rogers, R; Samuelson, J
Entamoeba histolytica is a microaerophilic protozoan parasite in which neither mitochondria nor mitochondrion-derived organelles have been previously observed. Recently, a segment of an E. histolytica gene was identified that encoded a protein similar to the mitochondrial 60-kDa heat shock protein (Hsp60 or chaperonin 60), which refolds nuclear-encoded proteins after passage through organellar membranes. The possible function and localization of the amebic Hsp60 were explored here. Like Hsp60 of mitochondria, amebic Hsp60 RNA and protein were both strongly induced by incubating parasites at 42 degreesC. 5' and 3' rapid amplifications of cDNA ends were used to obtain the entire E. histolytica hsp60 coding region, which predicted a 536-amino-acid Hsp60. The E. histolytica hsp60 gene protected from heat shock Escherichia coli groEL mutants, demonstrating the chaperonin function of the amebic Hsp60. The E. histolytica Hsp60, which lacked characteristic carboxy-terminal Gly-Met repeats, had a 21-amino-acid amino-terminal, organelle-targeting presequence that was cleaved in vivo. This presequence was necessary to target Hsp60 to one (and occasionally two or three) short, cylindrical organelle(s). In contrast, amebic alcohol dehydrogenase 1 and ferredoxin, which are bacteria-like enzymes, were diffusely distributed throughout the cytosol. We suggest that the Hsp60-associated, mitochondrion-derived organelle identified here be named "crypton," as its structure was previously hidden and its function is still cryptic.
Effect of some parameters in the response of the Perspex 3042, Lot L amber dosemeters; Efectos de algunos parametros en la respuesta de los dosimetros ambar Perspex 3042, Lote L
Energy Technology Data Exchange (ETDEWEB)
Prieto M, E.F.; Barrera G, G. [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN). Calle 30, No. 502, esq. 5ta. Avenida, Playa, Ciudad de La Habana (Cuba)]. e-mail: firstname.lastname@example.com
The answer of the dosimetric systems is affected by several factors, for what should know as these factors they influence in each one of the different dosimetric systems and by this way to minimize its effect in the value of the absorbed dose and to obtain exact dose values. One of the dosimetric systems more used in the high dose dosimetry like routine dosemeter for the control of the irradiation process are the Perspex dosemeters, for their speed in the obtaining the information, their easy manipulation and the precision that they present. To this dosemeters group they belong the same as the Red and Clear the Amber, which are adequate for the measurement of the radiation dose in the range of high doses. The objective of the present work is to obtain the calibration curves of the dosemeters Amber Perspex 3042, Lot L under our work conditions, like they are the irradiation temperatures and of storage and to know the influence of the rate dose in the value of the absorbed dose for different measurement wavelengths, as well as, the relationship among the one post-irradiation time and the specific absorbance value induced in function of the absorbed dose. (Author)
Pro-inflammatory cytokines downregulate Hsp27 and cause apoptosis of human retinal capillary endothelial cells
Nahomi, Rooban B.; Palmer, Allison; Roth, Katelyn E.; Fort, Patrice E.; Nagaraj, Ram H.
The formation of acellular capillaries in the retina, a hallmark feature of diabetic retinopathy, is caused by apoptosis of endothelial cells and pericytes. The biochemical mechanism of such apoptosis remains unclear. Small heat shock proteins play an important role in the regulation of apoptosis. In the diabetic retina, pro-inflammatory cytokines are upregulated. In this study, we investigated the effects of pro-inflammatory cytokines on small heat shock protein 27 (Hsp27) in human retinal endothelial cells (HREC). In HREC cultured in the presence of cytokine mixtures (CM), a significant downregulation of Hsp27 at the protein and mRNA level occurred, with no effect on HSF-1, the transcription factor for Hsp27. The presence of high glucose (25 mM) amplified the effects of cytokines on Hsp27. CM activated indoleamine 2,3-dioxygenase (IDO) and enhanced the production of kynurenine and ROS. An inhibitor of IDO, 1-methyl tryptophan (MT), inhibited the effects of CM on Hsp27. CM also upregulated NOS2 and, consequently, nitric oxide (NO). A NOS inhibitor, L-NAME, and a ROS scavenger blocked the CM-mediated Hsp27 downregulation. While a NO donor in the culture medium did not decrease the Hsp27 content, a peroxynitrite donor and exogenous peroxynitrite did. The cytokines and high glucose-induced apoptosis of HREC were inhibited by MT and L-NAME. Downregulation of Hsp27 by a siRNA treatment promoted apoptosis in HREC. Together, these data suggest that pro-inflammatory cytokines induce the formation of ROS and NO, which, through the formation of peroxynitrite, reduce the Hsp27 content and bring about apoptosis of retinal capillary endothelial cells. PMID:24252613
Localization of Hsp27 in the Rat Submandibular Gland Following the Application of Various Surgical Treatments
International Nuclear Information System (INIS)
Salivary glands repair and regenerate following various types of injuries and surgical procedures. However, the tissue responses induced in the contralateral glands have yet to be elucidated in detail. Hsp27, a member of the heat-shock protein (Hsp) family, is strongly expressed in physiological environments, particularly during development. Hsp27 was previously shown to play a role in the regulation of acinar cell proliferation and differentiation in the rat submandibular gland. The present study performed the following surgical treatments on the right submandibular glands of adult rats: 1) duct ligation followed by unligation after one week; 2) partial sialoadenectomy; and 3) total sialoadenectomy. Immunohistochemistry for Hsp27 and Ki67 was performed in the experimental and normal contralateral glands, and localization was histologically and morphometrically analyzed. The results obtained revealed the localization of Hsp27 to the intercalated duct in the submandibular glands of non-treated rats. The expression of Hsp27 was strongly induced in both the uninjured contralateral control glands as well as treated glands of experimental rats regardless of the surgical procedure performed. The number of Hsp27-immunopositive cells increased rapidly following surgery, and subsequently returned to the same level as that in non-treated rats after 4 weeks. However, no marked changes were observed in the number of Ki67-immunopositive proliferating cells. Therefore, the change in the number of Hsp27-immunopositive cells may have contributed to compensatory hypertrophy. The results of the present study indicate that the expression of Hsp27 in the intercalated duct in the submandibular gland may play a role in the differentiation of acinar cells
PP2A mediated AMPK inhibition promotes HSP70 expression in heat shock response.
Directory of Open Access Journals (Sweden)
Ting Wang
Full Text Available BACKGROUND: Under stress, AMP-activated protein kinase (AMPK plays a central role in energy balance, and the heat shock response is a protective mechanism for cell survival. The relationship between AMPK activity and heat shock protein (HSP expression under stress is unclear. METHODOLOGY/PRINCIPAL FINDINGS: We found that heat stress induced dephosphorylation of AMPKα subunit (AMPKα in various cell types from human and rodent. In HepG2 cells, the dephosphorylation of AMPKα under heat stress in turn caused dephosphorylation of acetyl-CoA carboxylase and upregulation of phosphoenolpyruvate carboxykinase, two downstream targets of AMPK, confirming the inhibition of AMPK activity by heat stress. Treatment of HepG2 cells with phosphatase 2A (PP2A inhibitor okadaic acid or inhibition of PP2A expression by RNA interference efficiently reversed heat stress-induced AMPKα dephosphorylation, suggesting that heat stress inhibited AMPK through activation of PP2A. Heat stress- and other HSP inducer (CdCl(2, celastrol, MG132-induced HSP70 expression could be inhibited by AICAR, an AMPK specific activator. Inhibition of AMPKα expression by RNA interference reversed the inhibitory effect of AICAR on HSP70 expression under heat stress. These results indicate that AMPK inhibition under stress contribute to HSP70 expression. Mechanistic studies showed that activation of AMPK by AICAR had no effect on heat stress-induced HSF1 nuclear translocation, phosphorylation and binding with heat response element in the promoter region of HSP70 gene, but significantly decreased HSP70 mRNA stability. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that during heat shock response, PP2A mediated AMPK inhibition upregulates HSP70 expression at least partially through stabilizing its mRNA, which suggests a novel mechanism for HSP induction under stress.
Correlation of HSP110 expression with all-trans retinoic acid-induced apoptosis.
Evrard, L; Vanmuylder, N; Dourov, N; Hermans, C; Biermans, J; Werry-Huet, A; Rooze, M; Louryan, S
In a previous study, we observed the strong expression of a stress protein of the HSP100/Clp family (HSP110) in apoptotic mesectodermal cells during early mouse facial development. In the present study, we describe the strong expression of the same HSP110 in mesectodermal cells undergoing apoptosis after all-trans retinoic acid (RA) administration. We used a teratological model known to increase cell deaths mainly in the first and second branchial arches during mammalian cephalogenesis: the treatment of E9 mouse embryos with all-trans RA, which results in craniofacial malformations comparable to those that characterize mandibulofacial dysostosis in man. Pregnant NMRI mice were treated with 60 mg/kg body weight of all-trans RA, given orally on day 9 of gestation; embryos were taken 4, 12 or 24 hr after RA administration. The apoptotic pattern of RA-induced cell deaths was confirmed using the dUTP biotin nick-end labeling (TUNEL) method and transmission electron microscopy (TEM). HSP110 expression was detected using an immunohistochemical approach. The increase in the number of TUNEL-positive cells and HSP110-positive cells after all-trans RA administration was quantified in the first branchial arch using a computerized method. Twelve hours after RA administration, the increase in the number of HSP110-positive cells is greater than the increase in the number of TUNEL-positive cells. Twenty-four hours after RA administration, only TUNEL-positive cells remain strong in number. We suggest that HSP110 expression could represent a biochemical event of apoptotic cell death induced by RA, associated with early stages of the apoptotic process. In order to find out if HSP110 expression resulted from neosynthesis, we performed in situ hybridization, which demonstrated that the expression of HSP110 occurred at the level of mRNA.
Probing molecular mechanisms of the Hsp90 chaperone: biophysical modeling identifies key regulators of functional dynamics.
Directory of Open Access Journals (Sweden)
Anshuman Dixit
Full Text Available Deciphering functional mechanisms of the Hsp90 chaperone machinery is an important objective in cancer biology aiming to facilitate discovery of targeted anti-cancer therapies. Despite significant advances in understanding structure and function of molecular chaperones, organizing molecular principles that control the relationship between conformational diversity and functional mechanisms of the Hsp90 activity lack a sufficient quantitative characterization. We combined molecular dynamics simulations, principal component analysis, the energy landscape model and structure-functional analysis of Hsp90 regulatory interactions to systematically investigate functional dynamics of the molecular chaperone. This approach has identified a network of conserved regions common to the Hsp90 chaperones that could play a universal role in coordinating functional dynamics, principal collective motions and allosteric signaling of Hsp90. We have found that these functional motifs may be utilized by the molecular chaperone machinery to act collectively as central regulators of Hsp90 dynamics and activity, including the inter-domain communications, control of ATP hydrolysis, and protein client binding. These findings have provided support to a long-standing assertion that allosteric regulation and catalysis may have emerged via common evolutionary routes. The interaction networks regulating functional motions of Hsp90 may be determined by the inherent structural architecture of the molecular chaperone. At the same time, the thermodynamics-based "conformational selection" of functional states is likely to be activated based on the nature of the binding partner. This mechanistic model of Hsp90 dynamics and function is consistent with the notion that allosteric networks orchestrating cooperative protein motions can be formed by evolutionary conserved and sparsely connected residue clusters. Hence, allosteric signaling through a small network of distantly connected
Radiation therapy induces circulating serum Hsp72 in patients with prostate cancer
International Nuclear Information System (INIS)
Background and purpose: Hsp72 found in the extracellular milieu has been shown to play an important role in immune regulation. The impact of common cancer therapies on extracellular release of Hsp72 however, has been to date undefined. Materials and methods: Serum from 13 patients undergoing radiation therapy (XRT) for prostate cancer with or without hormonal therapy (ADT) was measured for levels of circulating serum Hsp72 and pro-inflammatory cytokines (IL-6 and TNF-α) using the classical sandwich ELISA technique and the relative expression of CD8+ T lymphocytes and natural killer (NK) cells was measured using flow cytometry. Mouse orthotopic xenograft of human prostate cancer tumors (DU-145 and PC-3) were used to validate and further characterize the response noted in the clinical setting. The biological significance of tumor released Hsp72 was studied in human dendritic cells (DC) in vitro. Results: Circulating serum Hsp72 levels increased an average of 3.5-fold (median per patient 4.8-fold) with XRT but not with ADT (p = 0.0002). Increases in IL-6 (3.3-fold), TNF-α (1.8-fold), CD8+ CTL (2.1-fold) and NK cells (3.2-fold) also occurred. Using PC-3 and DU-145 human prostate cancer xenograft models in mice, we confirmed that XRT induces Hsp72 release primarily from implanted tumors. In vitro studies using supernatant recovered from irradiated human prostate cancer cells point to exosomes containing Hsp72 as a possible stimulator of pro-inflammatory cytokine production and costimulatory molecules expression in human DC. Conclusions: The current study confirms for the first time in an actual clinical setting elevation of circulating serum Hsp72 with XRT. The accompanying studies in mice and in vitro identify the released exosomes containing Hsp72 as playing a pivotal role in stimulating pro-inflammatory immune responses. These findings, if validated, may lead to new treatment paradigms for common human malignancies.
Cloning and expression analysis of a HSP70 gene from Korean rockfish (Sebastes schlegeli).
Mu, Weijie; Wen, Haishen; Li, Jifang; He, Feng
The gene encoding HSP70 was isolated from Korean rockfish Sebastes schlegeli by homologous cloning and rapid amplification of cDNA ends (RACE). The full-length of HSP70 cDNA was composed of 2259 bp and encoded a polypeptide of 639 amino acids. BLAST analysis showed that HSP70 of S. schlegeli shared high identities with those of the Lates calcarifer, Oreochromis niloticus, Seriola quinqueradiata HSP70s (88-89%). Our current study also revealed that HSP70 of Korean rockfish was expressed in many tissues by RT-PCR under unstressed condition. Quantitative real-time PCR showed that the expression patterns of Korean rockfish HSP70 were developmental stage-dependency. The expression of HSP70 was measured by quantitative real-time PCR after different oxygen treatments. The results showed that expression of HSP70 increased significantly after exposure to hypoxia for 30 min in gill and ovary, and then decreased for 60 min, and the level in spleen and liver gradually increased and reached the highest at 60 min. In addition, in gill, spleen and liver, the HSP70 mRNA level reached the maximum in hypoxia group after one hour different oxygen concentration stress. Increased amounts of serum thyroxine (T4), and triiodothyronine (T3) were also found during 30 min hypoxia treatment and 60 min normoxia group in our study. All of the results provide information to further study the mechanism of physiology and immune function under stress conditions of ovoviviparous teleosts. PMID:23877000
Treatment of Arabidopsis thaliana seeds with an HSP90 inhibitor increases plant resistance
Kozeko, Liudmyla
Resistance of plants to unfavourable conditions is an important feature to use them as an autotrophic link of Life Support Systems in space exploration missions. It significantly depends on basic and stress-induced levels of heat shock proteins (HSP) in cells. It is known that HSP90 can bind and maintain heat shock transcription factors (HSF) as a monomer that lacks DNA binding activity and thereby regulate HSP expression. Modulation of activity of the HSP synthesis and resistance by HSP90 in plants is not well investigated. The objective of this study was to determine how treatment of seeds with an HSP90 inhibitor affects environmental responsiveness in Arabidopsis thaliana. Seed treatment with geldanamycin (GDA) was used to reduce HSP90 function. The affect of space flight stressors was simulated by gamma-irradiation and thermal upshift. Two series of experiments were carried out: 1) exposure of dry seeds to gamma-irradiation (1 kGy, ^{60}Co); 2) heat shock of seedlings. It was shown that GDA treatment of seeds stimulated the seedling growth after seed irradiation. It also increased both the basic thermotolerance (45°C for 45 min) and induced thermotolerance (45°C for 1,5-2,5 h after pretreatment at 37°C for 2 h) in seedlings. In addition, seed treatment with GDA had a prolonged effect on the HSP70 production in seedlings under normal and stressful conditions. It shows that the stimulatory effects of GDA may be caused by induction of HSP70 synthesis. The obtained data demonstrate that pre-treatment of seeds with GDA before planting allows inducing the stress resistance at least at early growth stages of plants.
Hsp27 enhances recovery of splicing as well as rephosphorylation of SRp38 after heat shock
Marin Vinader, L.; Shin, C.; Onnekink, C; Manley, J L; Lubsen, N H
A heat stress causes a rapid inhibition of splicing. Exogenous expression of Hsp27 did not prevent that inhibition but enhanced the recovery of splicing afterward. Another small heat shock protein, αB-crystallin, had no effect. Hsp27, but not αB-crystallin, also hastened rephosphorylation of SRp38—dephosphorylated a potent inhibitor of splicing—after a heat shock, although it did not prevent dephosphorylation by a heat shock. The effect of Hsp27 on rephosphorylation of SRp38 required phosphor...
Resistance to HSP90 inhibition involving loss of MCL1 addiction
Busacca, S.; Law, E. W P; Powley, I R; Proia, D A; Sequeira, M.; Le Quesne, J; Klabatsa, A.; Edwards, J. M.; Matchett, K. B.; Luo, J. L.; Pringle, J. H.; El-Tanani, M.; MacFarlane, M; Fennell, D A
Inhibition of the chaperone heat-shock protein 90 (HSP90) induces apoptosis, and it is a promising anti-cancer strategy. The mechanisms underpinning apoptosis activation following HSP90 inhibition and how they are modified during acquired drug resistance are unknown. We show for the first time that, to induce apoptosis, HSP90 inhibition requires the cooperation of multi BH3-only proteins (BID, BIK, PUMA) and the reciprocal suppression of the pro-survival BCL-2 family member MCL1, which occurs...
HSP70 expression in the copper butterfly Lycaena tityrus across altitudes and temperatures
DEFF Research Database (Denmark)
Karl, I.; Sørensen, Jesper Givskov; Loeschcke, Volker;
The ability to express heat-shock proteins (HSP) under thermal stress is an essential mechanism for ectotherms to cope with unfavourable conditions. In this study, we investigate if Copper butterflies originating from different altitudes and/or being exposed to different rearing and induction...... temperatures show differences in HSP70 expression. HSP70 expression increased substantially at the higher rearing temperature in low-altitude butterflies, which might represent an adaptation to occasionally occurring heat spells. On the other hand, high-altitude butterflies showed much less plasticity...
Hsp27gene in Drosophila ananassae subgroup was split by a recently acquired intron
Indian Academy of Sciences (India)
InDrosophila , heat shock protein 27 (Hsp27) is a critical single-copy intron-free nuclear gene involved in the defense responseagainst fungi and bacteria, and is a regulator of adult lifespan. In the present study, 33 homologousHsp27nucleotide sequencesfrom differentDrosophilaspecies were amplified by PCR and reverse transcription PCR, and the phylogenetic relationshipswere analysed using neighbour-joining, maximum-likelihood and Bayesian methods. The phylogenetic topologies from anal-ysis with different algorithms were similar, suggesting that theHsp27gene was split by a recently acquired intron during theevolution of theDrosophila ananassaesubgroup
Reactive oxygen species generated by a heat shock protein (Hsp) inducing product contributes to Hsp70 production and Hsp70-mediated protective immunity in Artemia franciscana against pathogenic vibrios.
Baruah, Kartik; Norouzitallab, Parisa; Linayati, Linayati; Sorgeloos, Patrick; Bossier, Peter
The cytoprotective role of heat shock protein (Hsp70) described in a variety of animal disease models, including vibriosis in farmed aquatic animals, suggests that new protective strategies relying upon the use of compounds that selectively turn on Hsp genes could be developed. The product Tex-OE® (hereafter referred to as Hspi), an extract from the skin of the prickly pear fruit, Opuntia ficus indica, was previously shown to trigger Hsp70 synthesis in a non-stressful situation in a variety of animals, including in a gnotobiotically (germ-free) cultured brine shrimp Artemia franciscana model system. This model system offers great potential for carrying out high-throughput, live-animal screens of compounds that have health benefit effects. By using this model system, we aimed to disclose the underlying cause behind the induction of Hsp70 by Hspi in the shrimp host, and to determine whether the product affects the shrimp in inducing resistance towards pathogenic vibrios. We provide unequivocal evidences indicating that during the pretreatment period with Hspi, there is an initial release of reactive oxygen species (hydrogen peroxide and/or superoxide anion), generated by the added product, in the rearing water and associated with the host. The reactive molecules generated are the triggering factors responsible for causing Hsp70 induction within Artemia. We have also shown that Hspi acts prophylactically at an optimum dose regimen to confer protection against pathogenic vibrios. This salutary effect was associated with upregulation of two important immune genes, prophenoloxidase and transglutaminase of the innate immune system. These findings suggest that inducers of stress protein (e.g. Hsp70) are potentially important modulator of immune responses and might be exploited to confer protection to cultured shrimp against Vibrio infection. PMID:24950414
The regulatory mechanism of Hsp90α secretion from endothelial cells and its role in angiogenesis during wound healing
International Nuclear Information System (INIS)
Research highlights: → Growth factors such as bFGF, VEGF, PDGF and SDF-1 stimulate Hsp90α secretion from endothelial cells. → Secreted Hsp90α localizes on the leading edge of activated endothelial cells. → Secreted Hsp90α promotes angiogenesis in wound healing. -- Abstract: Heat shock protein 90α (Hsp90α) is a ubiquitously expressed molecular chaperone, which is essential for the maintenance of eukaryote homeostasis. Hsp90α can also be secreted extracellularly and is associated with several physiological and pathological processes including wound healing, cancer, infectious diseases and diabetes. Angiogenesis, defined as the sprouting of new blood vessels from pre-existing capillaries via endothelial cell proliferation and migration, commonly occurs in and contributes to the above mentioned processes. However, the secretion of Hsp90α from endothelial cells and also its function in angiogenesis are still unclear. Here we investigated the role of extracellular Hsp90α in angiogenesis using dermal endothelial cells in vitro and a wound healing model in vivo. We find that the secretion of Hsp90α but not Hsp90β is increased in activated endothelial cells with the induction of angiogenic factors and matrix proteins. Secreted Hsp90α localizes on the leading edge of endothelial cells and promotes their angiogenic activities, whereas Hsp90α neutralizing antibodies reverse the effect. Furthermore, using a mouse skin wound healing model in vivo, we demonstrate that extracellular Hsp90α localizes on blood vessels in granulation tissues of wounded skin and promotes angiogenesis during wound healing. Taken together, our study reveals that Hsp90α can be secreted by activated endothelial cells and is a positive regulator of angiogenesis, suggesting the potential application of Hsp90α as a stimulator for wound repair.
The regulatory mechanism of Hsp90{alpha} secretion from endothelial cells and its role in angiogenesis during wound healing
Energy Technology Data Exchange (ETDEWEB)
Song, Xiaomin [National Engineering Laboratory for Anti-tumor Protein Therapeutics, Tsinghua University, Beijing 100084 (China); Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, Beijing 100084 (China); Cancer Biology Laboratory, School of Life Sciences, Tsinghua University, Beijing 100084 (China); Luo, Yongzhang, E-mail: email@example.com [National Engineering Laboratory for Anti-tumor Protein Therapeutics, Tsinghua University, Beijing 100084 (China); Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, Beijing 100084 (China); Cancer Biology Laboratory, School of Life Sciences, Tsinghua University, Beijing 100084 (China)
Research highlights: {yields} Growth factors such as bFGF, VEGF, PDGF and SDF-1 stimulate Hsp90{alpha} secretion from endothelial cells. {yields} Secreted Hsp90{alpha} localizes on the leading edge of activated endothelial cells. {yields} Secreted Hsp90{alpha} promotes angiogenesis in wound healing. -- Abstract: Heat shock protein 90{alpha} (Hsp90{alpha}) is a ubiquitously expressed molecular chaperone, which is essential for the maintenance of eukaryote homeostasis. Hsp90{alpha} can also be secreted extracellularly and is associated with several physiological and pathological processes including wound healing, cancer, infectious diseases and diabetes. Angiogenesis, defined as the sprouting of new blood vessels from pre-existing capillaries via endothelial cell proliferation and migration, commonly occurs in and contributes to the above mentioned processes. However, the secretion of Hsp90{alpha} from endothelial cells and also its function in angiogenesis are still unclear. Here we investigated the role of extracellular Hsp90{alpha} in angiogenesis using dermal endothelial cells in vitro and a wound healing model in vivo. We find that the secretion of Hsp90{alpha} but not Hsp90{beta} is increased in activated endothelial cells with the induction of angiogenic factors and matrix proteins. Secreted Hsp90{alpha} localizes on the leading edge of endothelial cells and promotes their angiogenic activities, whereas Hsp90{alpha} neutralizing antibodies reverse the effect. Furthermore, using a mouse skin wound healing model in vivo, we demonstrate that extracellular Hsp90{alpha} localizes on blood vessels in granulation tissues of wounded skin and promotes angiogenesis during wound healing. Taken together, our study reveals that Hsp90{alpha} can be secreted by activated endothelial cells and is a positive regulator of angiogenesis, suggesting the potential application of Hsp90{alpha} as a stimulator for wound repair.
Expression and Significance of HSP70 and MGMT in Breast Neoplasms%HSP70和MGMT在乳腺肿瘤中的表达和意义
Institute of Scientific and Technical Information of China (English)
吴荣薇; 薄爱华; 王发亮; 芦广萍
目的:探讨乳腺肿瘤组织中热休克蛋白HSP70和DNA修复酶O6-甲基鸟嘌呤-DNA甲基转移酶(O6-methyguanine-DNA methytransferase,MGMT)的表达及临床意义.方法:采用免疫组织化学SABC法检测65例乳腺肿瘤组织中HSP70和MGMT的表达情况.结果:乳腺肿瘤中HSP70的阳性率为80.00%(52/65),MGMT的阳性率为60.00%(39/65),二者呈中度相关性(r=0.46).其中,有淋巴结转移组的阳性率高于无转移组(P<0.05).结论:HSP70和MGMT的表达率与淋巴结转移情况有关.检测HSP70与MGMT对乳腺肿瘤预后和化疗方案的选择有指导意义.
Ionizing radiation improves glioma-specific targeting of superparamagnetic iron oxide nanoparticles conjugated with cmHsp70.1 monoclonal antibodies (SPION-cmHsp70.1)
Shevtsov, Maxim A.; Nikolaev, Boris P.; Ryzhov, Vyacheslav A.; Yakovleva, Ludmila Y.; Marchenko, Yaroslav Y.; Parr, Marina A.; Rolich, Valerij I.; Mikhrina, Anastasiya L.; Dobrodumov, Anatolii V.; Pitkin, Emil; Multhoff, Gabriele
The stress-inducible 72 kDa heat shock protein Hsp70 is known to be expressed on the membrane of highly aggressive tumor cells including high-grade gliomas, but not on the corresponding normal cells. Membrane Hsp70 (mHsp70) is rapidly internalized into tumor cells and thus targeting of mHsp70 might provide a promising strategy for theranostics. Superparamagnetic iron oxide nanoparticles (SPIONs) are contrast negative agents that are used for the detection of tumors with MRI. Herein, we conjugated the Hsp70-specific antibody (cmHsp70.1) which is known to recognize mHsp70 to superparamagnetic iron nanoparticles to assess tumor-specific targeting before and after ionizing irradiation. In vitro experiments demonstrated the selectivity of SPION-cmHsp70.1 conjugates to free and mHsp70 in different tumor cell types (C6 glioblastoma, K562 leukemia, HeLa cervix carcinoma) in a dose-dependent manner. High-resolution MRI (11 T) on T2-weighted images showed the retention of the conjugates in the C6 glioma model. Accumulation of SPION-cmHsp70.1 nanoparticles in the glioma resulted in a nearly 2-fold drop of values in comparison to non-conjugated SPIONs. Biodistribution analysis using NLR-M2 measurements showed a 7-fold increase in the tumor-to-background (normal brain) uptake ratio of SPION-cmHsp70.1 conjugates in glioma-bearing rats in comparison to SPIONs. This accumulation within Hsp70-positive glioma was further enhanced after a single dose (10 Gy) of ionizing radiation. Elevated accumulation of the magnetic conjugates in the tumor due to radiosensitization proves the combination of radiotherapy and application of Hsp70-targeted agents in brain tumors.The stress-inducible 72 kDa heat shock protein Hsp70 is known to be expressed on the membrane of highly aggressive tumor cells including high-grade gliomas, but not on the corresponding normal cells. Membrane Hsp70 (mHsp70) is rapidly internalized into tumor cells and thus targeting of mHsp70 might provide a promising strategy
Co-effects of extremely low frequency electromagnetic field (ELF-EMF) and temper-ature on hsp22 and hsp26 expression in Drosophila melanogaster%高温下极低频电磁场暴露对果蝇hsp22和hsp26基因影响的研究
Institute of Scientific and Technical Information of China (English)
张晶; 张紫燕; 杨传俊; 蔡澎
Objective To study the combined effect of extremely low frequency electromagnetic fields ( ELF-EMF ) exposure (50 Hz and 3 mT) and high temperature exposure on hsp22 and hsp26 expression in Drosophila melanogaster. Methods Under the conditions of 50 Hz and 3 mT ELF-EMF,the male and female D.melanogaster was separately exposed for 2 h at 25℃, 27.5℃, 30℃, 32.5℃,and 35℃, respectively.The death rate, exercise capacity and the hsp22 and hsp26 expression levels of D.melanogaster were detected after exposure;or at 25℃and 35℃at 2 h, 4 h, 8 h, and 24 h, respectively.The hsp22 and hsp26 expression levels of D.melanogaster were tested after exposure .Results After exposure for 2 h at 25℃, 27.5℃, 30℃, 32.5℃, and 35℃, temperature had a significant effect (P0.05).After exposure for 2 h at 25℃, 27.5℃, 30℃, 32.5℃, and 35℃, the hsp22 and hsp26 expression levels of D.melanogaster were significantly impacted(P<0.01) by gender, temperature, ELF-EMF and exposure time, and tem-perature was the most important factor .Gender, temperature, ELF-EMF and exposure time had some interaction with the results.Conclusion ELF-EMF can influence the expression levels of hsp22 and hsp26.ELF-EMF exposure contributes to heat tolerance in D.melanogaster through accelerated expression of hsp22 and hsp26.%目的:探讨在高温(35℃)条件下,极低频电磁场( extremely low frequency electromagnetic fields ,ELF-EMF)对雌雄黑腹果蝇hsp22和hsp26基因表达水平的影响。方法在25、27.5、30、32.5、35℃下,1日龄雌、雄黑腹果蝇在50 Hz、3 mT ELF-EMF暴露2 h,测定其死亡率、运动能力和hsp22、hsp26表达水平;在25和35℃下,1日龄雌、雄黑腹果蝇在50 Hz、3 mT ELF-EMF暴露2、4、8、24 h,测定其hsp22、hsp26表达水平。结果在25、27.5、30、32.5、35℃下暴露2 h,温度变化对果蝇的死亡率、运动能力和hsp22、hsp26表达水平有极显著影响(P<0.01),ELF-EMF对hsp
Posch, C.
Nature still outperforms the most powerful computers in routine functions involving perception, sensing and actuation like vision, audition, and motion control, and is, most strikingly, orders of magnitude more energy-efficient than its artificial competitors. The reasons for the superior performance of biological systems are subject to diverse investigations, but it is clear that the form of hardware and the style of computation in nervous systems are fundamentally different from what is used in artificial synchronous information processing systems. Very generally speaking, biological neural systems rely on a large number of relatively simple, slow and unreliable processing elements and obtain performance and robustness from a massively parallel principle of operation and a high level of redundancy where the failure of single elements usually does not induce any observable system performance degradation. In the late 1980`s, Carver Mead demonstrated that silicon VLSI technology can be employed in implementing ``neuromorphic'' circuits that mimic neural functions and fabricating building blocks that work like their biological role models. Neuromorphic systems, as the biological systems they model, are adaptive, fault-tolerant and scalable, and process information using energy-efficient, asynchronous, event-driven methods. In this paper, some basics of neuromorphic electronic engineering and its impact on recent developments in optical sensing and artificial vision are presented. It is demonstrated that bio-inspired vision systems have the potential to outperform conventional, frame-based vision acquisition and processing systems in many application fields and to establish new benchmarks in terms of redundancy suppression/data compression, dynamic range, temporal resolution and power efficiency to realize advanced functionality like 3D vision, object tracking, motor control, visual feedback loops, etc. in real-time. It is argued that future artificial vision systems
International Nuclear Information System (INIS)
Nature still outperforms the most powerful computers in routine functions involving perception, sensing and actuation like vision, audition, and motion control, and is, most strikingly, orders of magnitude more energy-efficient than its artificial competitors. The reasons for the superior performance of biological systems are subject to diverse investigations, but it is clear that the form of hardware and the style of computation in nervous systems are fundamentally different from what is used in artificial synchronous information processing systems. Very generally speaking, biological neural systems rely on a large number of relatively simple, slow and unreliable processing elements and obtain performance and robustness from a massively parallel principle of operation and a high level of redundancy where the failure of single elements usually does not induce any observable system performance degradation. In the late 1980's, Carver Mead demonstrated that silicon VLSI technology can be employed in implementing ''neuromorphic'' circuits that mimic neural functions and fabricating building blocks that work like their biological role models. Neuromorphic systems, as the biological systems they model, are adaptive, fault-tolerant and scalable, and process information using energy-efficient, asynchronous, event-driven methods. In this paper, some basics of neuromorphic electronic engineering and its impact on recent developments in optical sensing and artificial vision are presented. It is demonstrated that bio-inspired vision systems have the potential to outperform conventional, frame-based vision acquisition and processing systems in many application fields and to establish new benchmarks in terms of redundancy suppression/data compression, dynamic range, temporal resolution and power efficiency to realize advanced functionality like 3D vision, object tracking, motor control, visual feedback loops, etc. in real-time. It is argued that future artificial vision systems
Bio-oil fractionation and condensation
Brown, Robert C; Jones, Samuel T; Pollard, Anthony
A method of fractionating bio-oil vapors which involves providing bio-oil vapors comprising bio-oil constituents is described. The bio-oil vapors are cooled in a first stage which comprises a condenser having passages for the bio-oil separated by a heat conducting wall from passages for a coolant. The coolant in the condenser of the first stage is maintained at a substantially constant temperature, set at a temperature in the range of 75 to 100.degree. C., to condense a first liquid fraction of liquefied bio-oil constituents in the condenser of the first stage. The first liquid fraction of liquified bio-oil constituents from the condenser in the first stage is collected. Also described are steps for subsequently recovering further liquid fractions of liquefied bio-oil constituents. Particular compositions of bio-oil condensation products are also described.
Chemical proteomics-driven discovery of oleocanthal as an Hsp90 inhibitor.
Margarucci, Luigi; Monti, Maria Chiara; Cassiano, Chiara; Mozzicafreddo, Matteo; Angeletti, Mauro; Riccio, Raffaele; Tosco, Alessandra; Casapullo, Agostino
Hsp90, a key target in cancer therapy, has been identified as the main partner of oleocanthal, an olive oil bioactive compound. A combination of chemical and biological assays disclosed its mechanism of action at the molecular level. PMID:23703283
Changing of the HSP70 Content in the Baikal Endemic Sponges Lubomirskiidae Under Conditions of Hyperthermia
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Itskovich V.B.
Full Text Available Baikal endemic sponges (Lubomirskiidae make up the bulk of the benthos biomass of the lake. For the first time the changes in the content of HSP70 in response to elevated environment temperature were analyzed in three endemic species of Baikal sponges: Baikalospongia bacillifera (Dybowski, 1880, B. intermedia (Dybowski, 1880 and Swartschewskia papyracea (Dybowski, 1880. Interspecific variability of constitutive HSP70 level was revealed for representatives of the three analyzed Lubomirskiidae species. After exposure at 13 °С for 3 and 7 days opposite changes were noted in the amount of HSP70. Under conditions of hyperthermia the protein level decrease at Baikalospongia species, while at the S. papyracea HSP70 content slightly increased. The differences in the mechanisms of stress adaptation probably affect the thermal resistance of the species, as well as are evidence supporting their specific status.
Trichostatin A Extends the Lifespan of Drosophila melanogaster by Elevating hsp22 Expression
Institute of Scientific and Technical Information of China (English)
Dan TAO; Jun LU; Hui SUN; Yan-Mei ZHAO; Zhi-Gen YUAN; Xiao-Xue LI; Bai-Qu HUANG
The level of acetylation of histones in nucleosomes is related to the longevity of yeast and animals. However, the mechanisms by which acetylation and deacetylation affect longevity remain unclear.In present study, we investigated the influence of histone acetylation modification on the expression of hsp22gene and the lifespan in Drosophila melanogaster using histone deacetylase (HDAC) inhibitor Trichostatin A (TSA). The results showed that TSA could extend the lifespan of Drosophila melanogaster. Furthermore,TSA significantly promoted the hsp22 gene transcription, and affected the chromatin morphology at the locus of hsp22 gene along the polytene chromosome. Present data implicate that TSA may affect the lifespan of Drosophila through changing the level of histone acetylation and influencing the expression of hsp22 gene that is related to aging.
Hsp60 and p70S6K form a complex in human cardiomyocytes
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Kroupskaya I. V.
Full Text Available Molecular chaperon Hsp60 and protein kinase p70S6K play an important functional role in the regulation of cardiomyocytes vital function or apoptosis. Aim. To study a possibility of in vivo complex formation between Hsp60 and p70S6K in cardiomyocytes. Methods. Co-immunoprecipitation, Western-blot analysis. Results. We have identified in vivo interaction between molecular chaperone Hsp60 and two isoforms of proteinkinase p70S6K in human myocardium, normal and affected by cardiomyopathy. Conclusions. The results obtained suggest a possible participation of molecular chaperon Hsp60 in regulation of p70S6K activity in stressinduced apoptotic signaling pathway in cardiomyocytes.
BAG-1/SODD, HSP70, and HSP90 are potential prognostic markers of poor survival in node-negative breast carcinoma.
Davidson, Ben; Valborg Reinertsen, Kristin; Trinh, Don; Reed, Wenche; Bøhler, Per Johannes
The objective of this study was to analyze the expression and clinical role of 13 signaling molecules in a large cohort of breast carcinoma patients with long follow-up period. Breast carcinomas (n=410) were analyzed for protein expression of phosphorylated mitogen-activated protein kinases (p-ERK, p-JNK, p-p38) and phosphoinositide 3-kinase signaling pathway proteins (p-AKT, p-mTOR, p-p70S6K); the BAG family proteins BAG-1 and BAG-4/SODD; the antiapoptotic protein Bcl-2; the inhibitor of apoptosis family member Survivin; and the heat shock protein family members HSP27, HSP70, and HSP90. Protein expression was studied for association with clinicopathological parameters and survival. Significantly higher expression of p-AKT (Pmarkers in node-negative breast carcinoma that merit further research. PMID:27038683
A rat retinal damage model predicts for potential clinical visual disturbances induced by Hsp90 inhibitors
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Zhou, Dan, E-mail: email@example.com [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States); Liu, Yuan; Ye, Josephine; Ying, Weiwen; Ogawa, Luisa Shin; Inoue, Takayo; Tatsuta, Noriaki; Wada, Yumiko; Koya, Keizo [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States); Huang, Qin [Department of Pathology and Laboratory Medicine, Veterans Affairs Boston Healthcare System, 1400 VFW Parkway, West Roxbury, MA 02132 (United States); Bates, Richard C.; Sonderfan, Andrew J. [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States)
In human trials certain heat shock protein 90 (Hsp90) inhibitors, including 17-DMAG and NVP-AUY922, have caused visual disorders indicative of retinal dysfunction; others such as 17-AAG and ganetespib have not. To understand these safety profile differences we evaluated histopathological changes and exposure profiles of four Hsp90 inhibitors, with or without clinical reports of adverse ocular effects, using a rat retinal model. Retinal morphology, Hsp70 expression (a surrogate marker of Hsp90 inhibition), apoptotic induction and pharmacokinetic drug exposure analysis were examined in rats treated with the ansamycins 17-DMAG and 17-AAG, or with the second-generation compounds NVP-AUY922 and ganetespib. Both 17-DMAG and NVP-AUY922 induced strong yet restricted retinal Hsp70 up-regulation and promoted marked photoreceptor cell death 24 h after the final dose. In contrast, neither 17-AAG nor ganetespib elicited photoreceptor injury. When the relationship between drug distribution and photoreceptor degeneration was examined, 17-DMAG and NVP-AUY922 showed substantial retinal accumulation, with high retina/plasma (R/P) ratios and slow elimination rates, such that 51% of 17-DMAG and 65% of NVP-AUY922 present at 30 min post-injection were retained in the retina 6 h post-dose. For 17-AAG and ganetespib, retinal elimination was rapid (90% and 70% of drugs eliminated from the retina at 6 h, respectively) which correlated with lower R/P ratios. These findings indicate that prolonged inhibition of Hsp90 activity in the eye results in photoreceptor cell death. Moreover, the results suggest that the retina/plasma exposure ratio and retinal elimination rate profiles of Hsp90 inhibitors, irrespective of their chemical class, may predict for ocular toxicity potential. - Highlights: • In human trials some Hsp90 inhibitors cause visual disorders, others do not. • Prolonged inhibition of Hsp90 in the rat eye results in photoreceptor cell death. • Retina/plasma ratio and retinal
Activating HSP72 in Rodent Skeletal Muscle Increases Mitochondrial Number and Oxidative Capacity and Decreases Insulin Resistance
Henstridge, Darren C.; Bruce, Clinton R.; Drew, Brian G.; Tory, Kálmán; Kolonics, Attila; Estevez, Emma; Chung, Jason; Watson, Nadine; Gardner, Timothy; Lee-Young, Robert S.; Connor, Timothy; Watt, Matthew J.; Carpenter, Kevin; Hargreaves, Mark; McGee, Sean L.; Hevener, Andrea L.; Febbraio, Mark A.
Induction of heat shock protein (HSP)72 protects against obesity-induced insulin resistance, but the underlying mechanisms are unknown. Here, we show that HSP72 plays a pivotal role in increasing skeletal muscle mitochondrial number and oxidative metabolism. Mice overexpressing HSP72 in skeletal muscle (HSP72Tg) and control wild-type (WT) mice were fed either a chow or high-fat diet (HFD). Despite a similar energy intake when HSP72Tg mice were compared with WT mice, the HFD increased body weight, intramuscular lipid accumulation (triacylglycerol and diacylglycerol but not ceramide), and severe glucose intolerance in WT mice alone. Whole-body VO2, fatty acid oxidation, and endurance running capacity were markedly increased in HSP72Tg mice. Moreover, HSP72Tg mice exhibited an increase in mitochondrial number. In addition, the HSP72 coinducer BGP-15, currently in human clinical trials for type 2 diabetes, also increased mitochondrial number and insulin sensitivity in a rat model of type 2 diabetes. Together, these data identify a novel role for activation of HSP72 in skeletal muscle. Thus, the increased oxidative metabolism associated with activation of HSP72 has potential clinical implications not only for type 2 diabetes but also for other disorders where mitochondrial function is compromised. PMID:24430435
Identification and in silico analysis of the Citrus HSP70 molecular chaperone gene family
Fietto, Luciano G.; Maximiller D.L. Costa; Cosme D Cruz; De Souza, Alessandra A.; Machado, Marcos A; Fontes, Elizabeth P. B.
The completion of the genome sequencing of the Arabidopsis thaliana model system provided a powerful molecular tool for comparative analysis of gene families present in the genome of economically relevant plant species. In this investigation, we used the sequences of the Arabidopsis Hsp70 gene family to identify and annotate the Citrus Hsp70 genes represented in the CitEST database. Based on sequence comparison analysis, we identified 18 clusters that were further divided into 5 subgroups enc...
The effect of glutamine infusion on the inflammatory response and HSP70 during human experimental endotoxaemia
Andreasen, Anne Sofie; Pedersen-Skovsgaard, Theis; Mortensen, Ole Hartvig; van Hall, Gerrit; Moseley, Pope Lloyd; Pedersen, Bente Klarlund
Introduction Glutamine supplementation has beneficial effects on morbidity and mortality in critically ill patients, possibly in part through an attenuation of the proinflammatory cytokine response and a stimulation of heat shock protein (HSP)70. We infused either alanine-glutamine or saline during endotoxin challenge and measured plasma cytokines and HSP70 protein expression. Methods This crossover study, conducted in eight healthy young men, was double-blind, randomized and placebo-controll...
Hsp104 Overexpression Cures Saccharomyces cerevisiae [PSI+] by Causing Dissolution of the Prion Seeds
Park, Yang-Nim; Zhao, Xiaohong; Yim, Yang-In; Todor, Horia; Ellerbrock, Robyn; Reidy, Michael; Eisenberg, Evan; Masison, Daniel C.; Greene, Lois E.
The [PSI+] yeast prion is formed when Sup35 misfolds into amyloid aggregates. [PSI+], like other yeast prions, is dependent on the molecular chaperone Hsp104, which severs the prion seeds so that they pass on as the yeast cells divide. Surprisingly, however, overexpression of Hsp104 also cures [PSI+]. Several models have been proposed to explain this effect: inhibition of severing, asymmetric segregation of the seeds between mother and daughter cells, and dissolution of the prion seeds. First...
Tah1 helix-swap dimerization prevents mixed Hsp90 co-chaperone complexes
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Morgan, Rhodri M. L.; Pal, Mohinder; Roe, S. Mark; Pearl, Laurence H., E-mail: email@example.com; Prodromou, Chrisostomos, E-mail: firstname.lastname@example.com [University of Sussex, Falmer, Brighton BN1 9RQ (United Kingdom)
A helix swap involving the fifth helix between two adjacently bound Tah1 molecules restores the normal binding environment of the conserved MEEVD peptide of Hsp90. Dimerization also explains how other monomeric TPR-domain proteins are excluded from forming inappropriate mixed co-chaperone complexes with Hsp90 and Tah1. Specific co-chaperone adaptors facilitate the recruitment of client proteins to the Hsp90 system. Tah1 binds the C-terminal conserved MEEVD motif of Hsp90, thus linking an eclectic set of client proteins to the R2TP complex for their assembly and regulation by Hsp90. Rather than the normal complement of seven α-helices seen in other tetratricopeptide repeat (TPR) domains, Tah1 unusually consists of the first five only. Consequently, the methionine of the MEEVD peptide remains exposed to solvent when bound by Tah1. In solution Tah1 appears to be predominantly monomeric, and recent structures have failed to explain how Tah1 appears to prevent the formation of mixed TPR domain-containing complexes such as Cpr6–(Hsp90){sub 2}–Tah1. To understand this further, the crystal structure of Tah1 in complex with the MEEVD peptide of Hsp90 was determined, which shows a helix swap involving the fifth α-helix between two adjacently bound Tah1 molecules. Dimerization of Tah1 restores the normal binding environment of the bound Hsp90 methionine residue by reconstituting a TPR binding site similar to that in seven-helix-containing TPR domain proteins. Dimerization also explains how other monomeric TPR-domain proteins are excluded from forming inappropriate mixed co-chaperone complexes.
Immunohistochemical changes in the expression of HSP27 in exercised human vastus lateralis muscle
DEFF Research Database (Denmark)
Folkesson, M; Mackey, Abigail; Holm, L;
27 protein in muscle fibres from five of nine subjects. The number of fibres with accumulation of HSP27 in RE ranged from 0% to 32% with a mean of 6.3% of the total number of fibres. CONCLUSION: We conclude that this rapid HSP27 protein relocation after RE is an important player in the cellular...... remodelling of human muscle fibres in response to exercise involving high-force contractions, but not in response to endurance exercises....
Extensive Citrullination Promotes Immunogenicity of HSP90 through Protein Unfolding and Exposure of Cryptic Epitopes.
Travers, Timothy S; Harlow, Lisa; Rosas, Ivan O; Gochuico, Bernadette R; Mikuls, Ted R; Bhattacharya, Sanjoy K; Camacho, Carlos J; Ascherman, Dana P
Post-translational protein modifications such as citrullination have been linked to the breach of immune tolerance and clinical autoimmunity. Previous studies from our laboratory support this concept, demonstrating that autoantibodies targeting citrullinated isoforms of heat shock protein 90 (HSP90) are associated with rheumatoid arthritis complicated by interstitial lung disease. To further explore the relationship between citrullination and structural determinants of HSP90 immunogenicity, we employed a combination of ELISA-based epitope profiling, computational modeling, and mass-spectrometric sequencing of peptidylarginine deiminase (PAD)-modified protein. Remarkably, ELISAs involving selected citrullinated HSP90β/α peptides identified a key epitope corresponding to an internal Arg residue (R502 [HSP90β]/R510 [HSP90α]) that is normally buried within the crystal structure of native/unmodified HSP90. In vitro time/dose-response experiments reveal an ordered pattern of PAD-mediated deimination events culminating in citrullination of R502/R510. Conventional as well as scaled molecular dynamics simulations further demonstrate that citrullination of selected Arg residues leads to progressive disruption of HSP90 tertiary structure, promoting exposure of R502/R510 to PAD modification and subsequent autoantibody binding. Consistent with this process, ELISAs incorporating variably deiminated HSP90 as substrate Ag indicate a direct relationship between the degree of citrullination and the level of ex vivo Ab recognition. Overall, these data support a novel structural paradigm whereby citrullination-induced shifts in protein structure generate cryptic epitopes capable of bypassing B cell tolerance in the appropriate genetic context.
A Clp/Hsp100 Chaperone Functions in Myxococcus xanthus Sporulation and Self-Organization
Yan, Jinyuan; Garza, Anthony G.; Michael D. Bradley; Welch, Roy D.
The Clp/Hsp100 proteins are chaperones that play a role in protein degradation and reactivation. In bacteria, they exhibit a high degree of pleiotropy, affecting both individual and multicellular phenotypes. In this article, we present the first characterization of a Clp/Hsp100 homolog in Myxococcus xanthus (MXAN_4832 gene locus). Deletion of MXAN_4832 causes defects in both swarming and aggregation related to cell motility and the production of fibrils, which are an important component of th...
Using Lymphocyte and Plasma Hsp70 as Biomarkers for Assessing Coke Oven Exposure among Steel Workers
Yang, Xiaobo; Zheng, Jinping; Bai, Yun; Tian, Fengjie; Yuan, Jing; Sun, Jianya; Liang, Huashan; Guo, Liang; Tan, Hao; Chen, Weihong; Tanguay, Robert M.; Wu, Tangchun
Background Hsp70, an early-response protein induced when organisms are confronted with simple or complicated environmental stresses, can act as either a cellular protector or a danger signal. Objectives The goal of this study was to evaluate levels of lymphocyte and/or plasma Hsp70 as biomarkers for assessing exposure response to complex coke oven emissions (COEs). Methods We recruited 101 coke oven workers and determined levels of polycyclic aromatic hydrocarbon (PAH) exposure, urinary 1-hyd...
Enhanced Hsp70 expression protects against acute lung injury by modulating apoptotic pathways.
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Gabriella Aschkenasy
Full Text Available The Acute respiratory distress syndrome (ARDS is a highly lethal inflammatory lung disorder. Apoptosis plays a key role in its pathogenesis. We showed that an adenovirus expressing the 70 kDa heat shock protein Hsp70 (AdHSP protected against sepsis-induced lung injury. In this study we tested the hypothesis that AdHSP attenuates apoptosis in sepsis-induced lung injury. Sepsis was induced in rats via cecal ligation and double puncture (2CLP. At the time of 2CLP PBS, AdHSP or AdGFP (an adenoviral vector expressing green fluorescent protein were injected into the tracheas of septic rats. 48 hours later, lungs were isolated. One lung was fixed for TUNEL staining and immunohistochemistry. The other was homogenized to isolate cytosolic and nuclear protein. Immunoblotting, gel filtration and co-immunoprecipitation were performed in these extracts. In separate experiments MLE-12 cells were incubated with medium, AdHSP or AdGFP. Cells were stimulated with TNFα. Cytosolic and nuclear proteins were isolated. These were subjected to immunoblotting, co-immunoprecipitation and a caspase-3 activity assay. TUNEL assay demonstrated that AdHSP reduced alveolar cell apoptosis. This was confirmed by immunohistochemical detection of caspase 3 abundance. In lung isolated from septic animals, immunoblotting, co-immunoprecipitation and gel filtration studies revealed an increase in cytoplasmic complexes containing caspases 3, 8 and 9. AdHSP disrupted these complexes. We propose that Hsp70 impairs apoptotic cellular pathways via interactions with caspases. Disruption of large complexes resulted in stabilization of lower molecular weight complexes, thereby, reducing nuclear caspase-3. Prevention of apoptosis in lung injury may preserve alveolar cells and aid in recovery.
Heat Shock Protein 90 (HSP90 and Her2 in Adenocarcinomas of the Esophagus
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Julia Slotta-Huspenina
Full Text Available Her2 overexpression and amplification can be found in a significant subset of esophageal adenocarcinomas. The activity of Her2 has been shown to be modulated by molecular chaperones such as HSP90. We analyzed expression/amplification data for HSP90 and Her2 on 127 primary resected esophageal adenocarcinomas in order to evaluate a possible relationship between these two molecules. HSP90 expression determined by immunohistochemistry was observed in various levels. Thirty nine (39 tumors (30.7% were classified as Her2-positive according to their immunoreactivity and amplification status. There was a significant correlation between HSP90 expression and Her2-status (p = 0.008. This could also be demonstrated by quantitative protein expression analysis with reverse phase protein arrays (r = 0.9; p < 0.001. Her2-status was associated withpT-category (p = 0.041, lymph node metastases (p = 0.049 and tumor differentiation (p = 0.036 with a higher percentage of cases with negative Her2 status in lower tumor stagesA negative Her2-status was also associated with better survival in univariate and multivariate analysis (p = 0.001 and p = 0.014. For HSP90, no associations between clinical and pathological parameters were found. The observed association between HSP90 expression and Her2 suggests a co-regulation of these molecules in at least a subset of esophageal adenocarcinomas. Anti-HSP90 drugs, which recently have been introduced in cancer treatment, may also be an option for these tumors by targeting HSP90 alone or in combination with Her2.
HSP70 overexpression may play a protective role in the mouse embryos stimulated by CUMS
Li, Xiao-Hong; Pang, Hou-Qing; QIN, LANG; Jin, Song; Zeng, Xun; Bai, Yu; Li, Shang-Wei
Background We evaluated whether heat shock protein HSP70 plays a protective role in the embryos of Kunming mice subjected to chronic unpredictable mild stress. Methods Female mice were stimulated for 4 weeks with nine stressors and then divided into mild, moderate and severe stress groups. Superovulation was induced with a gonadotropin preparation (PMSG/HCG) and HSP70 expression in 2-cell embryos and day 4 embryos was detected by immunofluorescence (IF) and real-time polymerase chain reaction...
Antigen capture ELISA for the heat shock protein (hsp60) of Chlamydia trachomatis.
Horner, P J; Ali, M.; Parker, D.; Weber, J. N.; Taylor-Robinson, D.; McClure, M O
AIMS: To develop an indirect ELISA using the heat shock protein (hsp60) of Chlamydia trachomatis as antigen. METHODS: The hsp60 gene was amplified by PCR, expressed in the vector pDEV-107 and transformed into Escherichia coli. The recombinant protein, expressed as a beta-galactosidase fusion product, was captured onto a solid phase using a monoclonal antibody directed against beta-galactosidase. Following incubation with goat anti-human antibody conjugated to peroxidase and colour development...
Study on HSP70 Gene Expression in Different Tissue of Cyprinus carpio%鲤鱼HSP70基因组织表达差异研究
Institute of Scientific and Technical Information of China (English)
林亚秋; 李瑞文
[Objective] The aim of this study was to investigate whether HSP70 can be used as a stress monitoring indicator in Cyprinus carpio breeding. [Method] Based on HSP70 sequence of Cyprinus carpio (AY120894), one pair of primers was designed and synthesized, while the total RNA of liver tissues in Cyprinus carpio was extracted. Some cDNA fragments of Cyprinus carpio HSP70 were cloned by RT-PCR, and its differential expression in various tissues such as heart, intestine, mucus, gonad, swim bladder, gill and fin in Cyprinus carpio was also studied. [Result] The cDNA sequence of 480 bp was obtained from Cyprinus carpio HSP70 gene by RT-PCR amplification. Homology comparison between the deduced amino acid sequence after sequencing and that of other types of fish showed that the homology among Cyprinus carpio, Danio rerio, Ohcorhynehus mylciss, Paralichthys olivaceus, Xiphophoorus maculates and Carassius auratus was 96%, 98%, 98%, 96%, 96% and 96% respectively. The expression of HSP70 was detected in eight tissues of Cyprinus carpio. The expression was the highest in heart, followed by swim bladder and fin, but there was no significant difference between them (P>0.05). There was no significant difference among the expression in three tissues of intestine, mucus and fat (P>0.05), but their expression was significantly higher than those in gonad and gill (P<0.05). [Conclusion] HSP70 gene expression is a suitable criterion for monitoring the stress degree, stress capacity and healthy conditions in Cyprinus carpio breeding.
Silencing of Hsp27 and Hsp72 in glioma cells as a tool for programmed cell death induction upon temozolomide and quercetin treatment
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Jakubowicz-Gil, Joanna, E-mail: email@example.com [Department of Comparative Anatomy and Anthropology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin (Poland); Langner, Ewa [Department of Medical Biology, Institute of Agricultural Medicine, Jaczewskiego 2, 20-950 Lublin (Poland); Bądziul, Dorota [Department of Comparative Anatomy and Anthropology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin (Poland); Wertel, Iwona [1st Department of Gynaecology, University School of Medicine, Staszica 16, 20-081 Lublin (Poland); Rzeski, Wojciech [Department of Medical Biology, Institute of Agricultural Medicine, Jaczewskiego 2, 20-950 Lublin (Poland); Department of Immunology and Virology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin (Poland)
The aim of the present study was to investigate whether silencing of Hsp27 or Hsp72 expression in glioblastoma multiforme T98G and anaplastic astrocytoma MOGGCCM cells increases their sensitivity to programmed cell death induction upon temozolomide and/or quercetin treatment. Transfection with specific siRNA was performed for the Hsp gene silencing. As revealed by microscopic observation and flow cytometry, the inhibition of Hsp expression was correlated with severe apoptosis induction upon the drug treatment studied. No signs of autophagy were detected. This was correlated with a decreased mitochondrial membrane potential, increased level of cytochrome c in the cytoplasm, and activation of caspase 3 and caspase 9. All these results suggest that the apoptotic signal was mediated by an internal pathway. Additionally, in a large percentage of cells treated with temozolomide, with or without quercetin, granules within the ER system were found, which was accompanied by an increased level of caspase 12 expression. This might be correlated with ER stress. Quercetin and temozolomide also changed the shape of nuclei from circular to "croissant like" in both transfected cell lines. Our results indicate that blocking of Hsp27 and Hsp72 expression makes T98G cells and MOGGCCM cells extremely vulnerable to apoptosis induction upon temozolomide and quercetin treatment and that programmed cell death is initiated by an internal signal. - Highlights: • Hsps gene silencing induced severe apoptosis upon temozolomide–quercetin treatment • Apoptosis in transfected glioma cells was initiated by internal signal • Programmed cell death was preceded by ER stress • Temozolomide–quercetin treatment changed nuclei shape in transfected glioma cells.
An Impermeant Ganetespib Analog Inhibits Extracellular Hsp90-Mediated Cancer Cell Migration that Involves Lysyl Oxidase 2-like Protein
International Nuclear Information System (INIS)
Extracellular Hsp90 (eHsp90) activates a number of client proteins outside of cancer cells required for migration and invasion. Therefore, eHsp90 may serve as a novel target for anti-metastatic drugs as its inhibition using impermeant Hsp90 inhibitors would not affect the numerous vital intracellular Hsp90 functions in normal cells. While some eHsp90 clients are known, it is important to establish other proteins that act outside the cell to validate eHsp90 as a drug target to limit cancer spread. Using mass spectrometry we identified two precursor proteins Galectin 3 binding protein (G3BP) and Lysyl oxidase 2-like protein (LOXL2) that associate with eHsp90 in MDA-MB231 breast cancer cell conditioned media and confirmed that LOXL2 binds to eHsp90 in immunoprecipitates. We introduce a novel impermeant Hsp90 inhibitor STA-12-7191 derived from ganetespib and show that it is markedly less toxic to cells and can inhibit cancer cell migration in a dose dependent manner. We used STA-12-7191 to test if LOXL2 and G3BP are potential eHsp90 clients. We showed that while LOXL2 can increase wound healing and compensate for STA-12-7191-mediated inhibition of wound closure, addition of G3BP had no affect on this assay. These findings support of role for LOXL2 in eHsp90 stimulated cancer cell migration and provide preliminary evidence for the use of STA-12-7191 to inhibit eHsp90 to limit cancer invasion
An Impermeant Ganetespib Analog Inhibits Extracellular Hsp90-Mediated Cancer Cell Migration that Involves Lysyl Oxidase 2-like Protein
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McCready, Jessica [Department of Natural Sciences, Assumption College, Worcester, MA 01609 (United States); Wong, Daniel S. [Department of Developmental Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111 (United States); Cell and Molecular Physiology Program, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States); Burlison, Joseph A.; Ying, Weiwen [Synta Pharmaceuticals, Lexington, MA 02421 (United States); Jay, Daniel G., E-mail: firstname.lastname@example.com [Department of Developmental Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111 (United States); Cell and Molecular Physiology Program, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States)
Extracellular Hsp90 (eHsp90) activates a number of client proteins outside of cancer cells required for migration and invasion. Therefore, eHsp90 may serve as a novel target for anti-metastatic drugs as its inhibition using impermeant Hsp90 inhibitors would not affect the numerous vital intracellular Hsp90 functions in normal cells. While some eHsp90 clients are known, it is important to establish other proteins that act outside the cell to validate eHsp90 as a drug target to limit cancer spread. Using mass spectrometry we identified two precursor proteins Galectin 3 binding protein (G3BP) and Lysyl oxidase 2-like protein (LOXL2) that associate with eHsp90 in MDA-MB231 breast cancer cell conditioned media and confirmed that LOXL2 binds to eHsp90 in immunoprecipitates. We introduce a novel impermeant Hsp90 inhibitor STA-12-7191 derived from ganetespib and show that it is markedly less toxic to cells and can inhibit cancer cell migration in a dose dependent manner. We used STA-12-7191 to test if LOXL2 and G3BP are potential eHsp90 clients. We showed that while LOXL2 can increase wound healing and compensate for STA-12-7191-mediated inhibition of wound closure, addition of G3BP had no affect on this assay. These findings support of role for LOXL2 in eHsp90 stimulated cancer cell migration and provide preliminary evidence for the use of STA-12-7191 to inhibit eHsp90 to limit cancer invasion.
Molecular cloning and characterization of the MsHSP17.7 gene from Medicago sativa L.
Li, Zhen-Yi; Long, Rui-Cai; Zhang, Tie-Jun; Yang, Qing-Chuan; Kang, Jun-Mei
Heat shock proteins (HSPs) are ubiquitous protective proteins that play crucial roles in plant development and adaptation to stress, and the aim of this study is to characterize the HSP gene in alfalfa. Here we isolated a small heat shock protein gene (MsHSP17.7) from alfalfa by homology-based cloning. MsHSP17.7 contains a 477-bp open reading frame and encodes a protein of 17.70-kDa. The amino acid sequence shares high identity with MtHSP (93.98 %), PsHSP17.1 (83.13 %), GmHSP17.9 (74.10 %) and SlHSP17.6 (79.25 %). Phylogenetic analysis revealed that MsHSP17.7 belongs to the group of cytosolic class II small heat shock proteins (sHSP), and likely localizes to the cytoplasm. Quantitative RT-PCR indicated that MsHSP17.7 was induced by heat shock, high salinity, peroxide and drought stress. Prokaryotic expression indicated that the salt and peroxide tolerance of Escherichia coli was remarkably enhanced. Transgenic Arabidopsis plants overexpressing MsHSP17.7 exhibited increased root length of transgenic Arabidopsis lines under salt stress compared to the wild-type line. The malondialdehyde (MDA) levels in the transgenic lines were significantly lower than in wild-type, although proline levels were similar between transgenic and wild-type lines. MsHSP17.7 was induced by heat shock, high salinity, oxidative stress and drought stress. Overexpression analysis suggests that MsHSP17.7 might play a key role in response to high salinity stress. PMID:27193169
Heat acclimation attenuates physiological strain and the HSP72, but not HSP90 alpha, mRNA response to acute normobaric hypoxia
Gibson, OR; Turner, G.; Tuttle, JA; Taylor, L.; Watt, PW; Maxwell, NS
Heat acclimation (HA) attenuates physiological strain in hot conditions via phenotypic and cellular adaptation. The aim of this study was to determine whether HA reduced physiological strain, and heat shock protein (HSP) 72 and HSP90α mRNA responses in acute normobaric hypoxia. Sixteen male participants completed ten 90-min sessions of isothermic HA (40°C/40% relative humidity) or exercise training [control (CON); 20°C/40% relative humidity]. HA or CON were preceded (HYP1) and proceeded (HYP2...
Variation in Hsp70-1A Expression Contributes to Skin Color Diversity.
Murase, Daiki; Hachiya, Akira; Fullenkamp, Rachel; Beck, Anita; Moriwaki, Shigeru; Hase, Tadashi; Takema, Yoshinori; Manga, Prashiela
The wide range in human skin color results from varying levels of the pigment melanin. Genetic mechanisms underlying coloration differences have been explored, but identified genes do not account for all variation seen in the skin color spectrum. Post-transcriptional and post-translational regulation of factors that determine skin color, including melanin synthesis in epidermal melanocytes, melanosome transfer to keratinocytes, and melanosome degradation, is also critical for pigmentation. We therefore investigated proteins that are differentially expressed in melanocytes derived from either white or African American skin. Two-dimensional gel electrophoresis and mass spectrometry demonstrated that heat shock protein 70-1A (Hsp70-1A) protein levels were significantly higher in African American melanocytes compared with white melanocytes. Hsp70-1A expression significantly correlated with levels of tyrosinase, the rate-limiting melanogenic enzyme, consistent with a proposed role for Hsp70 family members in tyrosinase post-translational modification. In addition, pharmacologic inhibition and small interfering RNA-mediated downregulation of Hsp70-1A correlated with pigmentation changes in cultured melanocytes, modified human skin substitutes, and ex vivo skin. Furthermore, Hsp70-1A inhibition led to increased autophagy-mediated melanosome degradation in keratinocytes. Our data thus reveal that epidermal Hsp70-1A contributes to the diversity of skin color by regulating the amount of melanin synthesized in melanocytes and modulating autophagic melanosome degradation in keratinocytes. PMID:27094592
Expression of HSP90 and HIF-1α in human colorectal cancer tissue and its significance
Institute of Scientific and Technical Information of China (English)
Qiu-Ran; Xu; Xin; Liu; Ying-Min; Yao; Qing-Guang; Liu
Objective:To investigate the expression of HSP90 and HIF-1αin human colorectal cancer tissue,the influence of HSP90 and HIF-1αon human colorectal cancer biological behavior and their related factors.Methods:The expression of HSP90 and HIF-1 a protein in human colorectal cancer as well as normal tissue were detected by imnmnohistochemical method.Results:The positive expression rates of HSP90 and HIF-1αprotein in normal human colorectal tissue as well as colorectal cancer tissue were 30%vs.63.0%,15.0%vs.71.7%,respectively.There were significant difference(P=0.035 and P=0.005 respectively).The expression of HSP90 was significantly correlated with the differentiation,Dukes stages and lymph node metastasis(P<0.05),while the expression of HIF-1 a was significantly correlated with the Dukes stages and lymph node metastasis(P<0.05).Association analysis showed that the expression of HSF90 protein was significantly correlated with that of HIF-1αprotein(P<0.01).Conclusions:The expression of HSP90 and HIF—1αprotein may be related to the development,metastasis and invasion of human colorectal cancer,and their synergistic effects may participate in the development of the colorectal carcinoma.
Immunohistochemistry of human Hsp60 in health and disease: from autoimmunity to cancer.
Cappello, Francesco; de Macario, Everly Conway; Zummo, Giovanni; Macario, Alberto J L
Hsp60 (also called Cpn60) is a chaperonin with essential functions for cell physiology and survival. Additionally, its involvement in the pathogenesis of a number of diseases (e.g., some autoimmune disorders and cancer) is becoming evident with new research. For example, the distribution and levels of Hsp60 in cells and tissues have been found altered in many pathologic conditions, and the significance of these alterations is being investigated in a number of laboratories. The aim of this ongoing research is to determine the meaning of these Hsp60 alterations with regard to pathogenetic mechanisms, diagnosis, classification of lesions, and assessing of prognosis and response to treatment. Hsp60 occurs in the mitochondria, i.e., its typical residence according to classic knowledge, and also in other locales, such as the cytosol, the cell membrane, the intercellular space, and biological fluids (e.g., blood and cerebrospinal fluid). Detection and quantitative determinations in all these locations are becoming essential components of laboratory pathology in clinics and research. Consequently, immunohistochemistry targeting Hsp60 is also becoming essential for pathologists and researchers interested in disorders involving this chaperonin. In this chapter, we briefly summarize some recent discoveries on the participation of Hsp60 in the pathogenesis of human diseases and describe in detail how to perform immunohistochemical reactions for detecting the chaperonin, determining its location, and measuring its levels of expression.
J-dot targeting of an exported HSP40 in Plasmodium falciparum-infected erythrocytes.
Petersen, Wiebke; Külzer, Simone; Engels, Sonja; Zhang, Qi; Ingmundson, Alyssa; Rug, Melanie; Maier, Alexander G; Przyborski, Jude M
Plasmodium falciparum exports a large number of proteins to its host cell, the mature human erythrocyte, where they are involved in host cell modification. Amongst the proteins trafficked to the host cell, many are heat shock protein (HSP)40 homologues. We previously demonstrated that at least two exported PfHSP40s (referred to as PFE55 and PFA660) localise to mobile structures in the P. falciparum-infected erythrocyte (Kulzer et al., 2010), termed J-dots. The complete molecular content of these structures has not yet been completely resolved, however it is known that they also contain an exported HSP70, PfHSP70x, and are potentially involved in transport of the major cytoadherance ligand, PfEMP1, through the host cell. To understand more about the nature of the association of exported HSP40s with J-dots, here we have studied the signal requirements for recruitment of the proteins to these structures. By expressing various exported GFP chimeras, we can demonstrate that the predicted substrate binding domain is necessary and sufficient for J-dot targeting. This targeting only occurs in human erythrocytes infected with P. falciparum, as it is not conserved when expressing a P. falciparum HSP40 in Plasmodium berghei-infected murine red blood cells, suggesting that J-dots are P. falciparum-specific. This data reveals a new mechanism for targeting of exported proteins to intracellular structures in the P. falciparum-infected erythrocyte. PMID:27063072
Effect of betaine on HSP70 expression and cell survival during adaptation to osmotic stress.
Petronini, P G; De Angelis, E M; Borghetti, A F; Wheeler, K P
Induced expression of the HSP70 gene in 3T3 and SV-3T3 cells was monitored by measurements of the synthesis of HSP70 and of the cellular contents of both HSP70 and its mRNA. The presence of betaine (N-trimethylglycine) at concentrations of 2.5-25 mM decreased the induction of HSP70 gene expression caused by incubation of 3T3 and SV-3T3 cells in hypertonic (0.5 osM) medium. This effect was accompanied by an enhancement of SV-3T3 cell adaptation, assayed by colony formation, to the hyperosmotic conditions. In contrast, the presence of betaine did not affect HSP70 gene expression induced in these cells by heat shock. After 6 h incubation with 25 mM betaine under hypertonic (0.5 osM) conditions the intracellular concentration of betaine in SV-3T3 cells was about 195 mM, compared with about 70 mM under isotonic (0.3 osM) conditions. Hence, with this concentration of extracellular betaine, the marked increase in the accumulation of betaine within the cells presumably counteracts the imposed osmotic pressure and eliminates the signal that otherwise initiates increased expression of the HSP70 gene. PMID:8343134
Inhibition of Plasmodium falciparum Hsp90 Contributes to the Antimalarial Activities of Aminoalcohol-carbazoles.
Wang, Tai; Mäser, Pascal; Picard, Didier
Malaria caused by the protozoan parasite Plasmodium falciparum (Pf) remains a major public health problem throughout the developing world. One molecular target that should receive more attention is the molecular chaperone Hsp90. It is essential and highly conserved in all eukaryotes, including in protozoan parasites. We have identified an amino-alcohol carbazole (N-CBZ) as a PfHsp90-selective inhibitor by virtually docking a large set of antimalarial compounds, previously found in a phenotypic screen, into a PfHsp90-specific pocket. By correlating the ability of 30 additional N-CBZ derivatives to bind directly to PfHsp90 with their Pf-inhibitory activity, we found that these types of compounds are more likely to inhibit Pf growth if they bind PfHsp90. For plausible targets such as PfHsp90, our workflow may help identifying the molecular target for compounds found by screening large chemical libraries for a desired biological effect and, conversely, ensuring biological effectiveness for compounds affecting a particular target. PMID:27312008
Combined HSP90 and kinase inhibitor therapy: Insights from The Cancer Genome Atlas.
Schwartz, Harvey; Scroggins, Brad; Zuehlke, Abbey; Kijima, Toshiki; Beebe, Kristin; Mishra, Alok; Neckers, Len; Prince, Thomas
The merging of knowledge from genomics, cellular signal transduction and molecular evolution is producing new paradigms of cancer analysis. Protein kinases have long been understood to initiate and promote malignant cell growth and targeting kinases to fight cancer has been a major strategy within the pharmaceutical industry for over two decades. Despite the initial success of kinase inhibitors (KIs), the ability of cancer to evolve resistance and reprogram oncogenic signaling networks has reduced the efficacy of kinase targeting. The molecular chaperone HSP90 physically supports global kinase function while also acting as an evolutionary capacitor. The Cancer Genome Atlas (TCGA) has compiled a trove of data indicating that a large percentage of tumors overexpress or possess mutant kinases that depend on the HSP90 molecular chaperone complex. Moreover, the overexpression or mutation of parallel activators of kinase activity (PAKA) increases the number of components that promote malignancy and indirectly associate with HSP90. Therefore, targeting HSP90 is predicted to complement kinase inhibitors by inhibiting oncogenic reprogramming and cancer evolution. Based on this hypothesis, consideration should be given by both the research and clinical communities towards combining kinase inhibitors and HSP90 inhibitors (H90Ins) in combating cancer. The purpose of this perspective is to reflect on the current understanding of HSP90 and kinase biology as well as promote the exploration of potential synergistic molecular therapy combinations through the utilization of The Cancer Genome Atlas. PMID:26070366