query: Lymphadenopathy is observed in knockin mouse lacking the SHP-2 MAPK pathway.

positive: Dissection of signaling cascades through gp130 in vivo: reciprocal roles for STAT3- and SHP2-mediated signals in immune responses. We generated a series of knockin mouse lines, in which the cytokine receptor gp130-dependent STAT3 and/or SHP2 signals were disrupted, by replacing the mouse gp130 gene with human gp130 mutant cDNAs. The SHP2 signal-deficient mice (gp130F759/F759 were born normal but displayed splenomegaly and lymphadenopathy and an enhanced acute phase reaction. In contrast, the STAT3 signal-deficient mice (gp130FXQ/FXXQ) died perinatally, like the gp130-deficient mice (gp130D/D). The gp130F759/F759 mice showed prolonged gp130-induced STAT3 activation, indicating a negative regulatory role for SHP2. Th1-type cytokine production and IgG2a and IgG2b production were increased in the gp130F759/F759 mice, while they were decreased in the gp130FXXQ/FXXQ immune system. These results indicate that the balance of positive and negative signals generated through gp130 regulates the immune responses.

negative: Control of CNS Cell-Fate Decisions by SHP-2 and Its Dysregulation in Noonan Syndrome Within the developing mammalian CNS, growth factors direct multipotent precursors to generate neurons versus glia, a process that if perturbed might lead to neural dysfunction. In this regard, genetic mutations resulting in constitutive activation of the protein tyrosine phosphatase SHP-2 cause Noonan Syndrome (NS), which is associated with learning disabilities and mental retardation. Here, we demonstrate that genetic knockdown of SHP-2 in cultured cortical precursors or in the embryonic cortex inhibited basal neurogenesis and caused enhanced and precocious astrocyte formation. Conversely, expression of an NS SHP-2 mutant promoted neurogenesis and inhibited astrogenesis. Neural cell-fate decisions were similarly perturbed in a mouse knockin model that phenocopies human NS. Thus, SHP-2 instructs precursors to make neurons and not astrocytes during the neurogenic period, and perturbations in the relative ratios of these two cell types upon constitutive SHP-2 activation may contribute to the cognitive impairments in NS patients.

negative: Defective tryptophan catabolism underlies inflammation in mouse chronic granulomatous disease Half a century ago, chronic granulomatous disease (CGD) was first described as a disease fatally affecting the ability of children to survive infections. Various milestone discoveries have since been made, from an insufficient ability of patients’ leucocytes to kill microbes to the underlying genetic abnormalities. In this inherited disorder, phagocytes lack NADPH oxidase activity and do not generate reactive oxygen species, most notably superoxide anion, causing recurrent bacterial and fungal infections. Patients with CGD also suffer from chronic inflammatory conditions, most prominently granuloma formation in hollow viscera. The precise mechanisms of the increased microbial pathogenicity have been unclear, and more so the reasons for the exaggerated inflammatory response. Here we show that a superoxide-dependent step in tryptophan metabolism along the kynurenine pathway is blocked in CGD mice with lethal pulmonary aspergillosis, leading to unrestrained Vγ1+ γδ T-cell reactivity, dominant production of interleukin (IL)-17, defective regulatory T-cell activity and acute inflammatory lung injury. Although beneficial effects are induced by IL-17 neutralization or γδ T-cell contraction, complete cure and reversal of the hyperinflammatory phenotype are achieved by replacement therapy with a natural kynurenine distal to the blockade in the pathway. Effective therapy, which includes co-administration of recombinant interferon-γ (IFN-γ), restores production of downstream immunoactive metabolites and enables the emergence of regulatory Vγ4+ γδ and Foxp3+ αβ T cells. Therefore, paradoxically, the lack of reactive oxygen species contributes to the hyperinflammatory phenotype associated with NADPH oxidase deficiencies, through a dysfunctional kynurenine pathway of tryptophan catabolism. Yet, this condition can be reverted by reactivating the pathway downstream of the superoxide-dependent step.

negative: Murine embryonic stem cell differentiation is promoted by SOCS-3 and inhibited by the zinc finger transcription factor Klf4. Embryonic stem (ES) cells homozygous for a Shp-2 mutation (Shp-2(Delta46-110)) demonstrate leukemia inhibitory factor (LIF) hypersensitivity and increased LIF-stimulated phosphorylation of signal transducer and activator of transcription (STAT3). We hypothesized that LIF-responsive genes in Shp-2(Delta46-110) cells would represent potential candidates for molecules vital for ES cell self-renewal. Using microarray analysis, we detected 41 genes whose expression was modified by LIF in Shp-2(Delta46-110) ES cells. Induction of 2 significantly up-regulated genes, suppressor of cytokine signaling-3 (SOCS-3) and Kruppel-like factor 4 (Klf4), was verified using Northern blotting. ES cells overexpressing SOCS-3 had an increased capacity to differentiate to hematopoietic progenitors, rather than to self-renew. In contrast, ES cells overexpressing Klf4 had a greater capacity to self-renew based on secondary embryoid body (EB) formation. Klf4-transduced d6 EBs expressed higher levels of Oct-4, consistent with the notion that Klf4 promotes ES cell self-renewal. These findings verify the negative role of SOCS-3 on LIF signaling and provide a novel role for Klf4 in ES cell function.

negative: Regulation of Hippo pathway transcription factor TEAD by p38 MAPK-induced cytoplasmic translocation The Hippo pathway controls organ size and tissue homeostasis, with deregulation leading to cancer. The core Hippo components in mammals are composed of the upstream serine/threonine kinases Mst1/2, MAPK4Ks and Lats1/2. Inactivation of these upstream kinases leads to dephosphorylation, stabilization, nuclear translocation and thus activation of the major functional transducers of the Hippo pathway, YAP and its paralogue TAZ. YAP/TAZ are transcription co-activators that regulate gene expression primarily through interaction with the TEA domain DNA-binding family of transcription factors (TEAD). The current paradigm for regulation of this pathway centres on phosphorylation-dependent nucleocytoplasmic shuttling of YAP/TAZ through a complex network of upstream components. However, unlike other transcription factors, such as SMAD, NF-κB, NFAT and STAT, the regulation of TEAD nucleocytoplasmic shuttling has been largely overlooked. In the present study, we show that environmental stress promotes TEAD cytoplasmic translocation via p38 MAPK in a Hippo-independent manner. Importantly, stress-induced TEAD inhibition predominates YAP-activating signals and selectively suppresses YAP-driven cancer cell growth. Our data reveal a mechanism governing TEAD nucleocytoplasmic shuttling and show that TEAD localization is a critical determinant of Hippo signalling output.

negative: CD28 and ITK signals regulate autoreactive T cell trafficking Activation of self-reactive T cells and their trafficking to target tissues leads to autoimmune organ destruction. Mice lacking the co-inhibitory receptor cytotoxic T lymphocyte antigen-4 (CTLA-4) develop fatal autoimmunity characterized by lymphocytic infiltration into nonlymphoid tissues. Here, we demonstrate that the CD28 co-stimulatory pathway regulates the trafficking of self-reactive Ctla4(-/-) T cells to tissues. Concurrent ablation of the CD28-activated Tec family kinase ITK does not block spontaneous T cell activation but instead causes self-reactive Ctla4(-/-) T cells to accumulate in secondary lymphoid organs. Despite excessive spontaneous T cell activation and proliferation in lymphoid organs, Itk(-/-); Ctla4(-/-) mice are otherwise healthy, mount antiviral immune responses and exhibit a long lifespan. We propose that ITK specifically licenses autoreactive T cells to enter tissues to mount destructive immune responses. Notably, ITK inhibitors mimic the null mutant phenotype and also prevent pancreatic islet infiltration by diabetogenic T cells in mouse models of type 1 diabetes, highlighting their potential utility for the treatment of human autoimmune disorders.

negative: The p38/MK2-Driven Exchange between Tristetraprolin and HuR Regulates AU–Rich Element–Dependent Translation TNF expression of macrophages is under stringent translational control that depends on the p38 MAPK/MK2 pathway and the AU-rich element (ARE) in the TNF mRNA. Here, we elucidate the molecular mechanism of phosphorylation-regulated translation of TNF. We demonstrate that translation of the TNF-precursor at the ER requires expression of the ARE-binding and -stabilizing factor human antigen R (HuR) together with either activity of the p38 MAPK/MK2 pathway or the absence of the ARE-binding and -destabilizing factor tristetraprolin (TTP). We show that phosphorylation of TTP by MK2 decreases its affinity to the ARE, inhibits its ability to replace HuR, and permits HuR-mediated initiation of translation of TNF mRNA. Since translation of TTP's own mRNA is also regulated by this mechanism, an intrinsic feedback control of the inflammatory response is ensured. The phosphorylation-regulated TTP/HuR exchange at target mRNAs provides a reversible switch between unstable/non-translatable and stable/efficiently translated mRNAs.

negative: Crypt stem cells as the cells-of-origin of intestinal cancer Intestinal cancer is initiated by Wnt-pathway-activating mutations in genes such as adenomatous polyposis coli (APC). As in most cancers, the cell of origin has remained elusive. In a previously established Lgr5 (leucine-rich-repeat containing G-protein-coupled receptor 5) knockin mouse model, a tamoxifen-inducible Cre recombinase is expressed in long-lived intestinal stem cells. Here we show that deletion of Apc in these stem cells leads to their transformation within days. Transformed stem cells remain located at crypt bottoms, while fuelling a growing microadenoma. These microadenomas show unimpeded growth and develop into macroscopic adenomas within 3-5weeks. The distribution of Lgr5+ cells within stem-cell-derived adenomas indicates that a stem cell/progenitor cell hierarchy is maintained in early neoplastic lesions. When Apc is deleted in short-lived transit-amplifying cells using a different cre mouse, the growth of the induced microadenomas rapidly stalls. Even after 30weeks, large adenomas are very rare in these mice. We conclude that stem-cell-specific loss of Apc results in progressively growing neoplasia.

negative: Roles of induced expression of MAPK phosphatase-2 in tumor development in RET-MEN2A transgenic mice Germline mutations in the RET tyrosine kinase gene are responsible for the development of multiple endocrine neoplasia 2A and 2B (MEN2A and MEN2B). However, knowledge of the fundamental principles that determine the mutant RET-mediated signaling remains elusive. Here, we report increased expression of mitogen-activated protein kinase phosphatase-2 (MKP-2) in carcinomas developed in transgenic mice carrying RET with the MEN2A mutation (RET-MEN2A). The expression of MKP-2 was not only induced by RET-MEN2A or RET-MEN2B mutant proteins but also by the activation of endogenous RET by its ligand, glial cell line-derived neurotrophic factor (GDNF). MKP-2 expression was also evident in the MKK-f cell line, which was established from a mammary tumor developed in a RET-MEN2A transgenic mouse. Inhibition of MKP-2 attenuated the in vitro and in vivo proliferation of MKK-f cells, which was mediated by the suppression of cyclin B1 expression. Furthermore, we found that MKP-2 is highly expressed in medullary thyroid carcinomas derived from MEN2A patients. These findings suggest that the increased expression of MKP-2 may play a crucial role in oncogenic signaling downstream of mutant RET, leading to deregulation of cell cycle.

negative: Monitoring Tumorigenesis and Senescence In Vivo with a p16INK4a-Luciferase Model Monitoring cancer and aging in vivo remains experimentally challenging. Here, we describe a luciferase knockin mouse (p16(LUC)), which faithfully reports expression of p16(INK4a), a tumor suppressor and aging biomarker. Lifelong assessment of luminescence in p16(+/LUC) mice revealed an exponential increase with aging, which was highly variable in a cohort of contemporaneously housed, syngeneic mice. Expression of p16(INK4a) with aging did not predict cancer development, suggesting that the accumulation of senescent cells is not a principal determinant of cancer-related death. In 14 of 14 tested tumor models, expression of p16(LUC) was focally activated by early neoplastic events, enabling visualization of tumors with sensitivity exceeding other imaging modalities. Activation of p16(INK4a) was noted in the emerging neoplasm and surrounding stromal cells. This work suggests that p16(INK4a) activation is a characteristic of all emerging cancers, making the p16(LUC) allele a sensitive, unbiased reporter of neoplastic transformation.

negative: Salt-inducible kinase 2 links transcriptional coactivator p300 phosphorylation to the prevention of ChREBP-dependent hepatic steatosis in mice. Obesity and type 2 diabetes are associated with increased lipogenesis in the liver. This results in fat accumulation in hepatocytes, a condition known as hepatic steatosis, which is a form of nonalcoholic fatty liver disease (NAFLD), the most common cause of liver dysfunction in the United States. Carbohydrate-responsive element-binding protein (ChREBP), a transcriptional activator of glycolytic and lipogenic genes, has emerged as a major player in the development of hepatic steatosis in mice. However, the molecular mechanisms enhancing its transcriptional activity remain largely unknown. In this study, we have identified the histone acetyltransferase (HAT) coactivator p300 and serine/threonine kinase salt-inducible kinase 2 (SIK2) as key upstream regulators of ChREBP activity. In cultured mouse hepatocytes, we showed that glucose-activated p300 acetylated ChREBP on Lys672 and increased its transcriptional activity by enhancing its recruitment to its target gene promoters. SIK2 inhibited p300 HAT activity by direct phosphorylation on Ser89, which in turn decreased ChREBP-mediated lipogenesis in hepatocytes and mice overexpressing SIK2. Moreover, both liver-specific SIK2 knockdown and p300 overexpression resulted in hepatic steatosis, insulin resistance, and inflammation, phenotypes reversed by SIK2/p300 co-overexpression. Finally, in mouse models of type 2 diabetes and obesity, low SIK2 activity was associated with increased p300 HAT activity, ChREBP hyperacetylation, and hepatic steatosis. Our findings suggest that inhibition of hepatic p300 activity may be beneficial for treating hepatic steatosis in obesity and type 2 diabetes and identify SIK2 activators and specific p300 inhibitors as potential targets for pharmaceutical intervention.

negative: Regulated nucleo/cytoplasmic exchange of HOG1 MAPK requires the importin beta homologs NMD5 and XPO1. MAP kinase signaling modules serve to transduce extracellular signals to the nucleus of eukaryotic cells, but little is known about how signals cross the nuclear envelope. Exposure of yeast cells to increases in extracellular osmolarity activates the HOG1 MAP kinase cascade, which is composed of three tiers of protein kinases, namely the SSK2, SSK22 and STE11 MAPKKKs, the PBS2 MAPKK, and the HOG1 MAPK. Using green fluorescent protein (GFP) fusions of these kinases, we found that HOG1, PBS2 and STE11 localize to the cytoplasm of unstressed cells. Following osmotic stress, HOG1, but neither PBS2 nor STE11, translocates into the nucleus. HOG1 translocation occurs very rapidly, is transient, and correlates with the phosphorylation and activation of the MAP kinase by its MAPKK. HOG1 phosphorylation is necessary and sufficient for nuclear translocation, because a catalytically inactive kinase when phosphorylated is translocated to the nucleus as efficiently as the wild-type. Nuclear import of the MAPK under stress conditions requires the activity of the small GTP binding protein Ran-GSP1, but not the NLS-binding importin alpha/beta heterodimer. Rather, HOG1 import requires the activity of a gene, NMD5, that encodes a novel importin beta homolog. Similarly, export of dephosphorylated HOG1 from the nucleus requires the activity of the NES receptor XPO1/CRM1. Our findings define the requirements for the regulated nuclear transport of a stress-activated MAP kinase.

negative: Integrin-linked kinase expression is elevated in human cardiac hypertrophy and induces hypertrophy in transgenic mice. BACKGROUND Although numerous signaling pathways are known to be activated in experimental cardiac hypertrophy, the molecular basis of the hypertrophic response inherent in human heart diseases remains largely unknown. Integrin-linked kinase (ILK) is a multifunctional protein kinase that physically links beta-integrins with the actin cytoskeleton, suggesting a potential mechanoreceptor role. METHODS AND RESULTS Here, we show a marked increase in ILK protein levels in hypertrophic ventricles of patients with congenital and acquired outflow tract obstruction. This increase in ILK was associated with activation of the Rho family guanine triphosphatases, Rac1 and Cdc42, and known hypertrophic signaling kinases, including extracellular signal-related kinases (ERK1/2) and p70 S6 kinase. Transgenic mice with cardiac-specific expression of a constitutively active ILK (ILK(S343D)) or wild-type ILK (ILK(WT)) exhibited a compensated ventricular hypertrophic phenotype and displayed an activation profile of guanine triphosphatases and downstream protein kinases concordant with that seen in human hypertrophy. In contrast, transgenic mice with cardiomyocyte-restricted expression of a kinase-inactive ILK (ILK(R211A)) were unable to mount a compensatory hypertrophic response to angiotensin II in vivo. CONCLUSIONS Taken together, these results identify ILK-regulated signaling as a broadly adaptive hypertrophic response mechanism relevant to a wide range of clinical heart disease.

negative: Morin Attenuates Ovalbumin-Induced Airway Inflammation by Modulating Oxidative Stress-Responsive MAPK Signaling. Asthma is one of the most common inflammatory diseases characterized by airway hyperresponsiveness, inflammation, and remodeling. Morin, an active ingredient obtained from Moraceae plants, has been demonstrated to have promising anti-inflammatory activities in a range of disorders. However, its impacts on pulmonary diseases, particularly on asthma, have not been clarified. This study was designed to investigate whether morin alleviates airway inflammation in chronic asthma with an emphasis on oxidative stress modulation. In vivo, ovalbumin- (OVA-) sensitized mice were administered with morin or dexamethasone before challenge. Bronchoalveolar lavage fluid (BALF) and lung tissues were obtained to perform cell counts, histological analysis, and enzyme-linked immunosorbent assay. In vitro, human bronchial epithelial cells (BECs) were challenged by tumor necrosis factor alpha (TNF-α). The supernatant was collected for the detection of the proinflammatory proteins, and the cells were collected for reactive oxygen species (ROS)/mitogen-activated protein kinase (MAPK) evaluations. Severe inflammatory responses and remodeling were observed in the airways of the OVA-sensitized mice. Treatment with morin dramatically attenuated the extensive trafficking of inflammatory cells into the BALF and inhibited their infiltration around the respiratory tracts and vessels. Morin administration also significantly suppressed goblet cell hyperplasia and collagen deposition/fibrosis and dose-dependently inhibited the OVA-induced increases in IgE, TNF-α, interleukin- (IL-) 4, IL-13, matrix metalloproteinase-9, and malondialdehyde. In human BECs challenged by TNF-α, the levels of proteins such as eotaxin-1, monocyte chemoattractant protein-1, IL-8 and intercellular adhesion molecule-1, were consistently significantly decreased by morin. Western blotting and the 2',7'-dichlorofluorescein assay revealed that the increases in intracellular ROS and MAPK phosphorylation were abolished by morin, implying that ROS/MAPK signaling contributes to the relief of airway inflammation. Our findings indicate for the first time that morin alleviates airway inflammation in chronic asthma, which probably occurs via the oxidative stress-responsive MAPK pathway, highlighting a novel profile of morin as a potent agent for asthma management.

negative: Pancreatic tumor cells with mutant K-ras suppress ERK activity by MEK-dependent induction of MAP kinase phosphatase-2. Activating mutations within the K-ras gene occur in a high percentage of human pancreatic carcinomas. We reported previously that the presence of oncogenic, activated K-ras in human pancreatic carcinoma cell lines did not result in constitutive activation of the extracellular signal-regulated kinases (ERK1 and ERK2). In the present study, we further characterized the ERK signaling pathway in pancreatic tumor cell lines in order to determine whether the ERK pathway is subject to a compensatory downregulation. We found that the attenuation of serum-induced ERK activation was not due to a delay in the kinetics of ERK phosphorylation. Treatment with the tyrosine phosphatase inhibitor orthovanadate increased the level of ERK phosphorylation, implicating a vanadate-sensitive tyrosine phosphatase in the negative regulation of ERK. Furthermore, expression of a dual specificity phosphatase capable of inactivating ERK known as mitogen-activated protein (MAP) kinase phosphatase-2 (MKP-2) was elevated in most of the pancreatic tumor cell lines and correlated with the presence of active MAP kinase kinase (MEK). Taken together, these results suggest that pancreatic tumor cells expressing oncogenic K-ras compensate, in part, by upregulating the expression of MKP-2 to repress the ERK signaling pathway.

negative: LncRNA NEAT1/let-7a-5p axis regulates the cisplatin resistance in nasopharyngeal carcinoma by targeting Rsf-1 and modulating the Ras-MAPK pathway. The long non-coding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) was reported to be upregulated and be involved in oncogenic growth and drug resistance in nasopharyngeal carcinoma (NPC). However, the exact roles of NEAT1 and its underlying mechanisms in the drug resistance of NPC remain largely unclear. In this study, the expressions of NEAT1, let-72-5p and Rsf-1 mRNA were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The effects of NEAT1 and let-72-5p on cell proliferation and cisplatin resistance of NPC cells were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and 5-ethynyl-20-deoxyuridine (EdU) assay. Western blot analysis was performed to detect the protein levels of Rsf-1, Ras, p-Raf1, Raf1, p-MEK1, MEK1, p-ERK1/2 and ERK1/2. Xenograft tumor assay was done to elucidate the role of NEAT1 involved in NPC tumor growth in vivo. We found that NEAT1 was upregulated and let-7a-5p was downregulated in NPC tissues, as well as NPC cell lines. Inhibition of NEAT1 markedly repressed the cisplatin resistance of NPC cells. NEAT1 was demonstrated to interact with let-7a-5p. Besides, a negative correlation between NEAT1 and let-7a-5p expression was observed in NPC tissues. Rsf-1 was confirmed as a target of let-7a-5p. NEAT1 remarkably reversed the inhibitory effect of let-7q-5p on the cisplatin resistance of NPC cells in vitro. Additionally, NEAT1 knockdown inhibited the Ras-MAPK pathway in NPC cells. NEAT1 knockdown suppressed tumor growth in the presence of cisplatin in vivo. Overall, these findings suggest that NEAT1/let-7a-5p axis regulates the cisplatin resistance in NPC by targeting Rsf-1 and modulating the Ras-MAPK signaling pathway.

negative: Defective mast cell effector functions in mice lacking the CRACM1 pore subunit of store-operated calcium release–activated calcium channels CRACM1 (also called Orai1) constitutes the pore subunit of store-operated calcium release–activated calcium channels. A point mutation in the gene encoding CRACM1 is associated with severe combined immunodeficiency disease in humans. Here we generated CRACM1-deficient mice in which β-galactosidase activity 'reported' CRACM1 expression. CRACM1-deficient mice were smaller in size. Mast cells derived from CRACM1-deficient mice showed grossly defective degranulation and cytokine secretion, and the allergic reactions elicited in vivo were inhibited in CRACM1-deficient mice. We detected robust CRACM1 expression in skeletal muscles and some regions of the brain, heart and kidney but not in the lymphoid regions of thymus and spleen. In contrast, we found CRACM2 expression to be much higher in mouse T cells. In agreement with those findings, the store-operated calcium influx and development and proliferation of CRACM1-deficient T cells was unaffected. Thus, CRACM1 is crucial in mouse mast cell effector function, but mouse T cell calcium release–activated calcium channels are functional in the absence of CRACM1.

negative: A novel Ku70 function in colorectal homeostasis separate from nonhomologous end joining Ku70, a known nonhomologous end-joining (NHEJ) factor, also functions in tumor suppression, although this molecular mechanism remains uncharacterized. Previously, we showed that mice deficient for DNA ligase IV (Lig4), another key NHEJ factor, succumbed to aggressive lymphoma in the absence of tumor suppressor p53. However, the tumor phenotype is abrogated by the introduction of a hypomorphic mutant p53R172P, which impaired p53-mediated apoptosis but not cell-cycle arrest. However, Lig4−/−p53R172P mice succumbed to severe diabetes. To further elucidate the role of NHEJ and p53-mediated apoptosis in vivo, we bred Ku70−/− p53R172P mice. Unexpectedly, these mice were free of diabetes, although 80% of the mutant mice had abnormally enlarged colons with pronounced inflammation. Remarkably, most of these mutant mice progressed to dysplasia, adenoma and adenocarcinoma; this is in contrast to the Lig4−/−p53R172P phenotype, strongly suggesting an NHEJ-independent function of Ku70. Significantly, our analyses of Ku70−/−p53R172P colonic epithelial cells show nuclear stabilization of β-catenin accompanied by higher expression of cyclin D1 and c-Myc in affected colon sections than in control samples. This is not due to the p53 mutation, as Ku70−/− mice share this phenotype. Our results not only unravel a novel function of Ku70 essential for colon homeostasis, but also establish an excellent in vivo model in which to study how chronic inflammation and abnormal cellular proliferation underlie tumorigenesis and tumor progression in the colon.

negative: Loss of DExD/H box RNA helicase LGP2 manifests disparate antiviral responses. The DExD/H box RNA helicase retinoic acid-inducible gene I (RIG-I) and the melanoma differentiation-associated gene 5 (MDA5) are key intracellular receptors that recognize virus infection to produce type I IFN. A third helicase gene, Lgp2, is homologous to Rig-I and Mda5 but lacks a caspase activation and recruitment domain. We generated Lgp2-deficient mice and report that the loss of this gene greatly sensitizes cells to cytosolic polyinosinic/polycytidylic acid-mediated induction of type I IFN. However, negative feedback inhibition of IFN-beta transcription was found to be normal in the absence of LGP2, indicating that LGP2 is not the primary negative regulator of type I IFN production. Our data further indicate that Lgp2-/- mice exhibited resistance to lethal vesicular stomatitis virus infection, a virus whose replicative RNA intermediates are recognized specifically by RIG-I rather than by MDA5 to trigger the production of type I IFN. However, mice lacking LGP2 were observed to exhibit a defect in type I IFN production in response to infection by the encephalomyocarditis virus, the replication of which activates MDA5-dependent innate immune responses. Collectively, our data indicate a disparate regulatory role for LGP2 in the triggering of innate immune signaling pathways following RNA virus infection.

negative: The Ly49Q receptor plays a crucial role in neutrophil polarization and migration by regulating raft trafficking. Neutrophils rapidly undergo polarization and directional movement to infiltrate the sites of infection and inflammation. Here, we show that an inhibitory MHC I receptor, Ly49Q, was crucial for the swift polarization of and tissue infiltration by neutrophils. During the steady state, Ly49Q inhibited neutrophil adhesion by preventing focal-complex formation, likely by inhibiting Src and PI3 kinases. However, in the presence of inflammatory stimuli, Ly49Q mediated rapid neutrophil polarization and tissue infiltration in an ITIM-domain-dependent manner. These opposite functions appeared to be mediated by distinct use of effector phosphatase SHP-1 and SHP-2. Ly49Q-dependent polarization and migration were affected by Ly49Q regulation of membrane raft functions. We propose that Ly49Q is pivotal in switching neutrophils to their polarized morphology and rapid migration upon inflammation, through its spatiotemporal regulation of membrane rafts and raft-associated signaling molecules.

negative: Up-regulation of endothelial nitric-oxide synthase by endothelium-derived hyperpolarizing factor involves mitogen-activated protein kinase and protein kinase C signaling pathways. Cytochrome P450 (P450)-dependent metabolites of arachidonic acid, the epoxyeicosatrienoic acids (EETs), are proposed to be endothelium-derived hyperpolarizing factors (EDHF) that affect vascular tone; however, the effects of EDHF on endothelial-derived nitric oxide biosynthesis remain unknown. We examined the regulation of endothelial nitric-oxide synthase (eNOS) by EDHF and investigated the relevant signaling pathways involved. The P450 epoxygenases CYP102 F87V mutant, CYP2C11-CYPOR, and CYP2J2 were transfected into cultured bovine aortic endothelial cells, and the effects of endogenously formed or exogenously applied EETs on eNOS expression and activity were assessed. Transfection with the P450 epoxygenases led to increased eNOS protein expression, an effect that was attenuated by cotreatment with the P450 inhibitor 17-ODYA. Northern analysis demonstrated that P450 transfection led to increased eNOS mRNA levels consistent with an effect at the pretranslational level. P450 epoxygenase transfection resulted in increased eNOS activity as measured by the conversion of L-arginine to L-citrulline. Addition of synthetic EETs (50-200 nM) to the culture media also increased eNOS expression and activity. Treatment with mitogen-activated protein kinase (MAPK), MAPK kinase, and protein kinase C inhibitors apigenin, 2'-amino-3'-methoxyflavone (PD98059), and 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7), respectively, significantly inhibited the effects of P450 transfection on eNOS expression. Overexpression of P450 epoxygenases or addition of synthetic EETs increased Thr495 phosphorylation of eNOS, an effect that was inhibited by both apigenin and PD98059. Overexpression of P450 epoxygenases in rats resulted in increased aortic eNOS expression, providing direct evidence that EDHF can influence vascular eNOS levels in vivo. Based on this data, we conclude that EDHF up-regulates eNOS via activation of MAPK and protein kinase C signaling pathways.

negative: A point mutation in KINDLIN3 ablates activation of three integrin subfamilies in humans Monogenic deficiency diseases provide unique opportunities to define the contributions of individual molecules to human physiology and to identify pathologies arising from their dysfunction. Here we describe a deficiency disease in two human siblings that presented with severe bleeding, frequent infections and osteopetrosis at an early age. These symptoms are consistent with but more severe than those reported for people with leukocyte adhesion deficiency III (LAD-III). Mechanistically, these symptoms arose from an inability to activate the integrins expressed on hematopoietic cells, including platelets and leukocytes. Immortalized lymphocyte cell lines isolated from the two individuals showed integrin activation defects. Several proteins previously implicated in integrin activation, including Ras-associated protein-1 (RAP1) and calcium and diacylglycerol-regulated guanine nucleotide exchange factor-1 (CALDAG-GEF1), were present and functional in these cell lines. The genetic basis for this disease was traced to a point mutation in the coding region of the KINDLIN3 (official gene symbol FERMT3) gene. When wild-type KINDLIN-3 was expressed in the immortalized lymphocytes, their integrins became responsive to activation signals. These results identify a genetic disease that severely compromises the health of the affected individuals and establish an essential role of KINDLIN-3 in integrin activation in humans. Furthermore, allogeneic bone marrow transplantation was shown to alleviate the symptoms of the disease.

negative: Activation of AMP-activated protein kinase suppresses oxidized low-density lipoprotein-induced macrophage proliferation. Macrophage-derived foam cells play important roles in the progression of atherosclerosis. We reported previously that ERK1/2-dependent granulocyte/macrophage colony-stimulating factor (GM-CSF) expression, leading to p38 MAPK/ Akt signaling, is important for oxidized low density lipoprotein (Ox-LDL)-induced macrophage proliferation. Here, we investigated whether activation of AMP-activated protein kinase (AMPK) could suppress macrophage proliferation. Ox-LDL-induced proliferation of mouse peritoneal macrophages was assessed by [(3)H]thymidine incorporation and cell counting assays. The proliferation was significantly inhibited by the AMPK activator 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) and restored by dominant-negative AMPKalpha1, suggesting that AMPK activation suppressed macrophage proliferation. AICAR partially suppressed Ox-LDL-induced ERK1/2 phosphorylation and GM-CSF expression, suggesting that another mechanism is also involved in the AICAR-mediated suppression of macrophage proliferation. AICAR suppressed GM-CSF-induced macrophage proliferation without suppressing p38 MAPK/Akt signaling. GM-CSF suppressed p53 phosphorylation and expression and induced Rb phosphorylation. Overexpression of p53 or p27(kip) suppressed GM-CSF-induced macrophage proliferation. AICAR induced cell cycle arrest, increased p53 phosphorylation and expression, and suppressed GM-CSF-induced Rb phosphorylation via AMPK activation. Moreover, AICAR induced p21(cip) and p27(kip) expression via AMPK activation, and small interfering RNA (siRNA) of p21(cip) and p27(kip) restored AICAR-mediated suppression of macrophage proliferation. In conclusion, AMPK activation suppressed Ox-LDL-induced macrophage proliferation by suppressing GM-CSF expression and inducing cell cycle arrest. These effects of AMPK activation may represent therapeutic targets for atherosclerosis.

negative: Abnormal Spine Morphology and Enhanced LTP in LIMK-1 Knockout Mice In vitro studies indicate a role for the LIM kinase family in the regulation of cofilin phosphorylation and actin dynamics. In addition, abnormal expression of LIMK-1 is associated with Williams syndrome, a mental disorder with profound deficits in visuospatial cognition. However, the in vivo function of this family of kinases remains elusive. Using LIMK-1 knockout mice, we demonstrate a significant role for LIMK-1 in vivo in regulating cofilin and the actin cytoskeleton. Furthermore, we show that the knockout mice exhibited significant abnormalities in spine morphology and in synaptic function, including enhanced hippocampal long-term potentiation. The knockout mice also showed altered fear responses and spatial learning. These results indicate that LIMK-1 plays a critical role in dendritic spine morphogenesis and brain function.

negative: The Hippo signaling pathway restricts the oncogenic potential of an intestinal regeneration program. Although a developmental role for Hippo signaling in organ size control is well appreciated, how this pathway functions in tissue regeneration is largely unknown. Here we address this issue using a dextran sodium sulfate (DSS)-induced colonic regeneration model. We find that regenerating crypts express elevated Yes-associated protein (YAP) levels. Inactivation of YAP causes no obvious intestinal defects under normal homeostasis, but severely impairs DSS-induced intestinal regeneration. Conversely, hyperactivation of YAP results in widespread early-onset polyp formation following DSS treatment. Thus, the YAP oncoprotein must be exquisitely controlled in tissue regeneration to allow compensatory proliferation and prevent the intrinsic oncogenic potential of a tissue regeneration program.

negative: Integration of Smad and MAPK pathways: a link and a linker revisited. Cells develop by reading mixed signals. Nowhere is this clearer than in the highly dynamic processes that propel embryogenesis, when critical cell-fate decisions are made swiftly in response to well-orchestrated growthfactor combinations. Learning how diverse signaling pathways are integrated is therefore essential for understanding physiology. This requires the identification, in tangible molecular terms, of key nodes for pathway integration that operate in vivo. A report in this issue, on the integration of Smad and Ras/MAPK pathways during neural induction (Pera et al. 2003), provides timely insights into the relevance of one such node. Pera et al. (2003) report that FGF8 and IGF2—two growth factors that activate the Ras/MAPK pathway— favor neural differentiation and mesoderm dorsalization in Xenopus by inhibiting BMP (Bone Morphogenetic Protein) signaling. Mesoderm is formed from ectoderm in response to Nodal-related signals from the endoderm at the blastula stage and beyond (Fig. 1; for review, see De Robertis et al. 2000). BMP induces differentiation of ectoderm into epidermal cell fates at the expense of neural fates, and it ventralizes the mesoderm at the expense of dorsal fates (for review, see Weinstein and HemmatiBrivanlou 1999; De Robertis et al. 2000). Accordingly, neural differentiation and dorsal mesoderm formation are favored when BMP signaling is attenuated. Noggin, Chordin, Cerberus, and Follistatin, secreted by the Spemann organizer on the dorsal side at the gastrula stage, facilitate the formation of neural tissue by sequestering BMP (Weinstein and Hemmati-Brivanlou 1999; De Robertis et al. 2000). Experimentally blocking BMP signaling with a dominant-negative BMP receptor has a similar effect of promoting ectoderm neuralization (Weinstein and Hemmati-Brivanlou 1999). As it turns out, neural induction can also be achieved with FGF (fibroblast growth factor; Kengaku and Okamoto 1993; Lamb and Harland 1995; Hongo et al. 1999; Hardcastle et al. 2000; Streit et al. 2000; Wilson et al. 2000) and IGF (insulin-like growth factor; Pera et al. 2001; Richard-Parpaillon et al. 2002). Injection of transcripts encoding FGF8 or IFG2 into one animal-pole blastomere of a fourto eight-cell embryo results in an expanded neural plate at the injected side (Pera et al. 2003). Surprisingly, expression of a dominant-negative FGF receptor prevents neuralization of ectoderm explants by the BMP blocker Noggin (Launay et al. 1996). Likewise, the potent neuralizing effect of Chordin can be blocked by a dominant-negative FGF receptor or a morpholino oligonucleotide targeting the IGF receptor (Pera et al. 2003). Thus, the neuralizing effect of BMP inhibitors is somehow tied to FGF and IFG signaling. The question is, how? Because FGF8 and IFG2 activate MAPK, Pera et al. (2003) took heed from previous work showing that MAPK inhibits the BMP signal-transduction factor Smad1 (Kretzschmar et al. 1997a). Smad1 is directly phosphorylated by the BMP receptor, resulting in Smad1 activation (Kretzschmar et al. 1997b), and by MAPK in response to EGF, resulting in Smad1 inhibition (Kretzschmar et al. 1997a; Fig. 2). Smad transcription factors mediate gene responses to the entire TGF (Transforming Growth Factor) family, to which the BMPs belong (for review, see Massague 2000; Derynck and Zhang 2003). Smads 1, 5, and 8 act primarily downstream of BMP receptors and Smads 2 and 3 downstream of TGF , Activin and Nodal receptors. Smad proteins have two conserved globular domains—the MH1 and MH2 domains (Fig. 2). The MH1 domain is involved in DNA binding and the MH2 domain in binding to cytoplasmic retention factors, activated receptors, nucleoporins in the nuclear pore, and DNA-binding cofactors, coactivators, and corepressors in the nucleus (for review, see Shi and Massague 2003). Receptor-mediated phosphorylation occurs at the carboxy-terminal sequence SXS. This enables the nuclear accumulation of Smads and their association with the shared partner Smad4 to form transcriptional complexes that are interpreted by the cell as a function of the context (Massague 2000). Between the MH1 and MH2 domains lies a linker region of variable sequence and length. Attention was drawn to this region when it was found that EGF (epidermal growth factor), a classical activator of the Ras/ MAPK pathway, causes phosphorylation of the Smad1 linker at four MAPK sites (PXSP sequences; Kretzschmar et al. 1997a). This prevents the nuclear localization of Smad1 and inhibits BMP signaling. Mutation of these E-MAIL j-massague@ski.mskcc.org; FAX (212) 717-3298. Article and publication are at http://www.genesdev.org/cgi/doi/10.1101/ gad.1167003.

negative: B-catenin deficiency, but not Myc deletion, suppresses the immediate phenotypes of APC loss in the liver. Dysregulated Wnt signaling is seen in approximately 30% of hepatocellular carcinomas; thus, finding pathways downstream of the activation of Wnt signaling is key. Here, using cre-lox technology, we deleted the Apc gene in the adult mouse liver and observed a rapid increase in nuclear beta-catenin and c-Myc, which is associated with an induction of proliferation that led to hepatomegaly within 4 days of gene deletion. To investigate the downstream pathways responsible for these phenotypes, we analyzed the impact of inactivating APC in the context of deficiency of the potentially key effectors beta-catenin and c-Myc. beta-catenin loss rescues both the proliferation and hepatomegaly phenotypes after APC loss. However, c-Myc deletion, which rescues the phenotypes of APC loss in the intestine, had no effect on the phenotypes of APC loss in the liver. The consequences of the deregulation of the Wnt pathway within the liver are therefore strikingly different from those observed within the intestine, with the vast majority of Wnt targets being beta-catenin-dependent but c-Myc-independent in the liver.

negative: Senescent growth arrest in mesenchymal stem cells is bypassed by Wip1-mediated downregulation of intrinsic stress signaling pathways. Human mesenchymal stem cells (hMSCs) have been widely studied as a source of primary adult stem cells for cell therapy because of their multidifferentiation potential; however, the growth arrest (also known as "premature senescence") often found in hMSCs cultured in vitro has been a major obstacle to the in-depth characterization of these cells. In addition, the inability to maintain constant cell growth hampers the development of additional genetic modifications aimed at achieving desired levels of differentiation to specific tissues; however, the molecular mechanisms that govern this phenomenon remain unclear, with the exception of a few studies demonstrating that induction of p16INK4a is responsible for this senescence-like event. Here, we observed that the premature growth arrest in hMSCs occurs in parallel with the induction of p16INK4a, following abrogation of inhibitory phosphorylation of retinoblastoma protein. These stress responses were concurrent with increased formation of reactive oxygen species (ROSs) from mitochondria and increased p38 mitogen-activated protein kinase (MAPK) activity. The introduction of Wip1 (wild-type p53 inducible phosphatase-1), a well-studied stress modulator, significantly lowered p16INK4a expression and led to p38 MAPK inactivation, although it failed to affect the levels of ROSs. Moreover, the suppression of stress responses by Wip1 apparently extended the life span of hMSCs, compared with control conditions, while maintaining their multilineage differentiation potential. Based on these results, we suggest that senescent growth arrest in hMSCs may result from activation of stress signaling pathways and consequent onset of stress responses, due in part to ROS production during prolonged in vitro culture.

negative: Crosstalk between tumor and endothelial cells promotes tumor angiogenesis by MAPK activation of Notch signaling. While significant progress has been made in understanding the induction of tumor vasculature by secreted angiogenic factors, little is known regarding contact-dependent signals that promote tumor angiogenesis. Here, we report that the Notch ligand Jagged1 induced by growth factors via mitogen-activating protein kinase (MAPK) in head and neck squamous cell carcinoma (HNSCC) cells triggered Notch activation in neighboring endothelial cells (ECs) and promoted capillary-like sprout formation. Jagged1-expressing HNSCC cells significantly enhanced neovascularization and tumor growth in vivo. Moreover, the level of Jagged1 was significantly correlated with tumor blood vessel content and associated with HNSCC development. Our results elucidate a novel mechanism by which the direct interplay between tumor cells and ECs promotes angiogenesis through MAPK and Notch signaling pathways.

negative: Macrophages induce COX-2 expression in breast cancer cells: role of IL-1β autoamplification. Tumor-associated macrophages and high levels of cyclooxygenase-2 (COX-2) are associated with poor prognosis in breast cancer patients, but their potential interdependence has not been evaluated. The objective of this study was to determine whether macrophages regulate COX-2 expression in breast cancer cells. For this purpose, THP-1 cells were cocultured with HCC1954 breast cancer cells. Coculture led to increased COX-2 expression in the HCC1954 cells and elevated prostaglandin E(2) levels in conditioned media. Similar results were observed when THP-1 cells were incubated with HCC1937 breast cancer cells or when human monocyte-derived macrophages were cocultured with HCC1954 cells. Coculture triggered production of reactive oxygen species (ROS) in HCC1954 cells. COX-2 induction was blocked in cells preincubated with an reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor or by silencing p67PHOX, a subunit of NADPH oxidase. ROS production triggered activation of Src and mitogen-activated protein kinases (MAPKs). Blocking Src or MAPK activities or antagonizing the activator protein-1 (AP-1) transcription factor attenuated COX-2 induction in HCC1954 cells. Coculture caused rapid induction of interleukin-1β (IL-1β) in both breast cancer cells and macrophages. Increased IL-1β expression was blocked by an interleukin-1 receptor antagonist (IL-1Ra), suggesting autocrine and paracrine effects. Importantly, macrophage-induced COX-2 expression was blocked in HCC1954 cells preincubated with IL-1Ra or anti-IL-1β IgG. Together, these results indicate that macrophage-mediated induction of COX-2 in breast cancer cells is a consequence of IL-1β-mediated stimulation of ROS→Src→MAPK→AP-1 signaling. IL-1β-dependent induction of COX-2 in breast cancer cells provides a mechanism whereby macrophages contribute to tumor progression and potential therapeutic targets in breast cancer.

negative: Activation of the estrogen receptor through phosphorylation by mitogen-activated protein kinase. The phosphorylation of the human estrogen receptor (ER) serine residue at position 118 is required for full activity of the ER activation function 1 (AF-1). This Ser118 is phosphorylated by mitogen-activated protein kinase (MAPK) in vitro and in cells treated with epidermal growth factor (EGF) and insulin-like growth factor (IGF) in vivo. Overexpression of MAPK kinase (MAPKK) or of the guanine nucleotide binding protein Ras, both of which activate MAPK, enhanced estrogen-induced and antiestrogen (tamoxifen)-induced transcriptional activity of wild-type ER, but not that of a mutant ER with an alanine in place of Ser118. Thus, the activity of the amino-terminal AF-1 of the ER is modulated by the phosphorylation of Ser118 through the Ras-MAPK cascade of the growth factor signaling pathways.

negative: Glucose deprivation-induced cytotoxicity and alterations in mitogen-activated protein kinase activation are mediated by oxidative stress in multidrug-resistant human breast carcinoma cells. We previously observed that glucose deprivation induces cell death in multidrug-resistant human breast carcinoma cells (MCF-7/ADR). As a follow up we wished to test the hypothesis that metabolic oxidative stress was the causative process or at least the link between causative processes behind the cytotoxicity. In the studies described here, we demonstrate that mitogen-activated protein kinase (MAPK) was activated within 3 min of being in glucose-free medium and remained activated for 3 h. Glucose deprivation for 2-4 h also caused oxidative stress as evidenced by a 3-fold greater steady state concentration of oxidized glutathione and a 3-fold increase in pro-oxidant production. Glucose and glutamate treatment rapidly suppressed MAPK activation and rescued cells from cytotoxicity. Glutamate and the peroxide scavenger, pyruvate, rescued the cells from cell killing as well as suppressed pro-oxidant production. In addition the thiol antioxidant, N-acetyl-L-cysteine, rescued cells from glucose deprivation-induced cytotoxicity and suppressed MAPK activation. These results suggest that glucose deprivation-induced cytotoxicity and alterations in MAPK signal transduction are mediated by oxidative stress in MCF-7/ADR. These results also support the speculation that a common mechanism of glucose deprivation-induced cytotoxicity in mammalian cells may involve metabolic oxidative stress.

negative: Tissue-Specific Knockout of the Insulin Receptor in Pancreatic β Cells Creates an Insulin Secretory Defect Similar to that in Type 2 Diabetes Dysfunction of the pancreatic beta cell is an important defect in the pathogenesis of type 2 diabetes, although its exact relationship to the insulin resistance is unclear. To determine whether insulin signaling has a functional role in the beta cell we have used the Cre-loxP system to specifically inactivate the insulin receptor gene in the beta cells. The resultant mice exhibit a selective loss of insulin secretion in response to glucose and a progressive impairment of glucose tolerance. These data indicate an important functional role for the insulin receptor in glucose sensing by the pancreatic beta cell and suggest that defects in insulin signaling at the level of the beta cell may contribute to the observed alterations in insulin secretion in type 2 diabetes.


query: Only a minority of cells survive development after differentiation into stress-resistant spores.

positive: Exploitative and Hierarchical Antagonism in a Cooperative Bacterium Social organisms that cooperate with some members of their own species, such as close relatives, may fail to cooperate with other genotypes of the same species. Such noncooperation may take the form of outright antagonism or social exploitation. Myxococcus xanthus is a highly social prokaryote that cooperatively develops into spore-bearing, multicellular fruiting bodies in response to starvation. Here we have characterized the nature of social interactions among nine developmentally proficient strains of M. xanthus isolated from spatially distant locations. Strains were competed against one another in all possible pairwise combinations during starvation-induced development. In most pairings, at least one competitor exhibited strong antagonism toward its partner and a majority of mixes showed bidirectional antagonism that decreased total spore production, even to the point of driving whole populations to extinction. Differential response to mixing was the primary determinant of competitive superiority rather than the sporulation efficiencies of unmixed populations. In some competitive pairings, the dominant partner sporulated more efficiently in mixed populations than in clonal isolation. This finding represents a novel form of exploitation in bacteria carried out by socially competent genotypes and is the first documentation of social exploitation among natural bacterial isolates. Patterns of antagonistic superiority among these strains form a highly linear dominance hierarchy. At least some competition pairs construct chimeric, rather than segregated, fruiting bodies. The cooperative prokaryote M. xanthus has diverged into a large number of distinct social types that cooperate with clone-mates but exhibit intense antagonism toward distinct social types of the same species. Most lengthy migration events in nature may thus result in strong antagonism between migratory and resident populations, and this antagonism may have large effects on local population sizes and dynamics. Intense mutual antagonism appears to be more prevalent in this prokaryotic social species than has been observed in the eukaryotic social slime mold Dictyostelium discoideum, which also exhibits multicellular development. The finding of several cases of facultative social exploitation among these natural isolates suggests that such exploitation may occur frequently in nature in many prokaryotes with cooperative traits.

negative: Efficacy of Beta1 Integrin and EGFR Targeting in Sphere-Forming Human Head and Neck Cancer Cells BACKGROUND Resistance to radiotherapy continues to be a limiting factor in the treatment of cancer including head and neck squamous cell carcinoma (HNSCC). Simultaneous targeting of β1 integrin and EGFR was shown to have a higher radiosensitizing potential than mono-targeting in the majority of tested HNSCC cancer models. As tumor-initiating cells (TIC) are thought to play a key role for therapy resistance and recurrence and can be enriched in sphere forming conditions, this study investigated the efficacy of β1 integrin/EGFR targeting without and in combination with X-ray irradiation on the behavior of sphere-forming cells (SFC). METHODS HNSCC cell lines (UTSCC15, UTSCC5, Cal33, SAS) were injected subcutaneously into nude mice for tumor up-take and plated for primary and secondary sphere formation under non-adhesive conditions which is thought to reflect the enrichment of SFC and their self-renewal capacity, respectively. Treatment was accomplished by inhibitory antibodies for β1 integrin (AIIB2) and EGFR (Cetuximab) as well as X-ray irradiation (2 - 6 Gy single doses). Further, flow cytometry for TIC marker expression and cell cycling as well as Western blotting for DNA repair protein expression and phosphorylation were employed. RESULTS We found higher primary and secondary sphere forming capacity of SAS cells relative to other HNSCC cell lines, which was in line with the tumor up-take rates of SAS versus UTSCC15 cells. AIIB2 and Cetuximab administration had minor cytotoxic and no radiosensitizing effects on SFC. Intriguingly, secondary SAS spheres, representing the fraction of surviving SFC upon passaging, showed greatly enhanced radiosensitivity compared to primary spheres. Intriguingly, neither AIIB2 nor Cetuximab significantly altered basal sphere forming capacity and radiosensitivity. While an increased accumulation of G0/G1 phase cells was observable in secondary SAS spheres, DNA double strand break repair indicated no difference on the basis of significantly enhanced ATM and Chk2 dephosphorylation upon irradiation. CONCLUSIONS In the HNSCC model, sphere-forming conditions select for cells, which are unsusceptible to both anti-β1 integrin and anti-EGFR inhibitory antibodies. With regard to primary and secondary sphere formation, our data suggest that both of these SFC fractions express distinct survival strategies independent from β1 integrin and EGFR and that future work is warranted to better understand SFC survival and enrichment before and after treatment to untangle the underlying mechanisms for identifying novel, druggable cancer targets in SFC.

negative: β1 integrin mediates an alternative survival pathway in breast cancer cells resistant to lapatinib INTRODUCTION The overexpression of human epidermal growth factor receptor (HER)-2 in 20% of human breast cancers and its association with aggressive growth has led to widespread use of HER2-targeted therapies, such as trastuzumab (T) and lapatinib (L). Despite the success of these drugs, their efficacy is limited in patients whose tumors demonstrate de novo or acquired resistance to treatment. The β1 integrin resides on the membrane of the breast cancer cell, activating several elements of breast tumor progression including proliferation and survival. METHODS We developed a panel of HER2-overexpressing cell lines resistant to L, T, and the potent LT combination through long-term exposure and validated these models in 3D culture. Parental and L/T/LT-resistant cells were subject to HER2 and β1 integrin inhibitors in 3D and monitored for 12 days, followed by quantification of colony number. Parallel experiments were conducted where cells were either stained for Ki-67 and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) or harvested for protein and analyzed by immunoblot. Results were subjected to statistical testing using analysis of variance and linear contrasts, followed by adjustment with the Sidak method. RESULTS Using multiple cell lines including BT474 and HCC1954, we reveal that in L and LT resistance, where phosphorylation of EGFR/HER1, HER2, and HER3 are strongly inhibited, kinases downstream of β1 integrin--including focal adhesion kinase (FAK) and Src--are up-regulated. Blockade of β1 by the antibody AIIB2 abrogates this up-regulation and functionally achieves significant growth inhibition of L and LT resistant cells in 3D, without dramatically affecting the parental cells. SiRNA against β1 as well as pharmacologic inhibition of FAK achieve the same growth inhibitory effect. In contrast, trastuzumab-resistant cells, which retain high levels of phosphorylated EGFR/HER1, HER2, and HER3, are only modestly growth-inhibited by AIIB2. CONCLUSIONS Our data suggest that HER2 activity, which is suppressed in resistance involving L but not T alone, dictates whether β1 mediates an alternative pathway driving resistance. Our findings justify clinical studies investigating the inhibition of β1 or its downstream signaling moieties as strategies to overcome acquired L and LT resistance.

negative: Oxidative stress in cancer associated fibroblasts drives tumor-stroma co-evolution: A new paradigm for understanding tumor metabolism, the field effect and genomic instability in cancer cells. Loss of stromal fibroblast caveolin-1 (Cav-1) is a powerful single independent predictor of poor prognosis in human breast cancer patients, and is associated with early tumor recurrence, lymph node metastasis and tamoxifen-resistance. We developed a novel co-culture system to understand the mechanism(s) by which a loss of stromal fibroblast Cav-1 induces a "lethal tumor micro-environment. " Here, we propose a new paradigm to explain the powerful prognostic value of stromal Cav-1. In this model, cancer cells induce oxidative stress in cancer-associated fibroblasts, which then acts as a "metabolic" and "mutagenic" motor to drive tumor-stroma co-evolution, DNA damage and aneuploidy in cancer cells. More specifically, we show that an acute loss of Cav-1 expression leads to mitochondrial dysfunction, oxidative stress and aerobic glycolysis in cancer associated fibroblasts. Also, we propose that defective mitochondria are removed from cancer-associated fibroblasts by autophagy/mitophagy that is induced by oxidative stress. As a consequence, cancer associated fibroblasts provide nutrients (such as lactate) to stimulate mitochondrial biogenesis and oxidative metabolism in adjacent cancer cells (the "Reverse Warburg Effect"). We provide evidence that oxidative stress in cancer-associated fibroblasts is sufficient to induce genomic instability in adjacent cancer cells, via a bystander effect, potentially increasing their aggressive behavior. Finally, we directly demonstrate that nitric oxide (NO) over-production, secondary to Cav-1 loss, is the root cause for mitochondrial dysfunction in cancer associated fibroblasts. In support of this notion, treatment with anti-oxidants (such as N-acetyl-cysteine, metformin and quercetin) or NO inhibitors (L-NAME) was sufficient to reverse many of the cancer-associated fibroblast phenotypes that we describe. Thus, cancer cells use "oxidative stress" in adjacent fibroblasts (i) as an "engine" to fuel their own survival via the stromal production of nutrients and (ii) to drive their own mutagenic evolution towards a more aggressive phenotype, by promoting genomic instability. We also present evidence that the "field effect" in cancer biology could also be related to the stromal production of ROS and NO species. eNOS-expressing fibroblasts have the ability to downregulate Cav-1 and induce mitochondrial dysfunction in adjacent fibroblasts that do not express eNOS. As such, the effects of stromal oxidative stress can be laterally propagated, amplified and are effectively "contagious"--spread from cell-to-cell like a virus--creating an "oncogenic/mutagenic" field promoting widespread DNA damage.

negative: Self-assembling peptides optimize the post-traumatic milieu and synergistically enhance the effects of neural stem cell therapy after cervical spinal cord injury. INTRODUCTION The hostile environment after spinal cord injury (SCI) can compromise effects of regenerative therapies. We hypothesized that optimizing the post-traumatic environment with QL6 self-assembling peptides (SAPs) before neural precursor cell (NPC) transplantation would improve cell survival, differentiation and functional recovery. METHODS A total of 90 Wistar rats received a clip-compression SCI at C7. Within each of two study arms, animals were randomized into 5 groups (NPC, SAP, NPC+SAP, vehicle, and sham). SAPs and NPCs were injected into the spinal cord 1day and 14days post-injury, respectively. Animals received growth factors over 7days and were immunosuppressed. Rats were sacrificed at 4weeks and sections of the cervical spinal cord prepared for immunohistochemistry (first study arm). Neurological function was assessed weekly for 8weeks using a battery of behavioral tests. Nine weeks post-SCI, the corticospinal tract was assessed using fiber-tracking (second arm). RESULTS SAP-treated animals had significantly more surviving NPCs which showed increased differentiation to neurons and oligodendrocytes compared to controls. SAPs alone or in combination with NPCs resulted in smaller intramedullary cysts and larger volume of preserved tissue compared to other groups. The combined treatment group showed reduced astrogliosis and chondroitin sulfate proteoglycan deposition. Synaptic connectivity was increased in the NPC and combined treatment groups. Corticospinal tract preservation and behavioral outcomes improved with combinatorial treatment. CONCLUSION Injecting SAPs after SCI enhances subsequent NPC survival, integration and differentiation and improves functional recovery. STATEMENT OF SIGNIFICANCE The hostile environment after spinal cord injury (SCI) can compromise effects of regenerative therapies. We hypothesized that improving this environment with self-assembling peptides (SAPs) before neural precursor cell (NPC) transplantation would support their beneficial effects. SAPs assemble once injected, providing a supportive scaffold for repair and regeneration. We investigated this in a rat model of spinal cord injury. More NPCs survived in SAP-treated animals and these showed increased differentiation compared to controls. SAPS alone or in combination with NPCs resulted in smaller cysts and larger volume of preserved tissue with the combined treatment also reducing scarring and improving behavioral outcomes. Overall, injection of SAPs was shown to improve the efficacy of NPC treatment, a promising finding for those with SCIs.

negative: Hypoxia in cancer: significance and impact on clinical outcome Hypoxia, a characteristic feature of locally advanced solid tumors, has emerged as a pivotal factor of the tumor (patho-)physiome since it can promote tumor progression and resistance to therapy. Hypoxia represents a “Janus face” in tumor biology because (a) it is associated with restrained proliferation, differentiation, necrosis or apoptosis, and (b) it can also lead to the development of an aggressive phenotype. Independent of standard prognostic factors, such as tumor stage and nodal status, hypoxia has been suggested as an adverse prognostic factor for patient outcome. Studies of tumor hypoxia involving the direct assessment of the oxygenation status have suggested worse disease-free survival for patients with hypoxic cervical cancers or soft tissue sarcomas. In head & neck cancers the studies suggest that hypoxia is prognostic for survival and local control. Technical limitations of the direct O2 sensing technique have prompted the use of surrogate markers for tumor hypoxia, such as hypoxia-related endogenous proteins (e.g., HIF-1α, GLUT-1, CA IX) or exogenous bioreductive drugs. In many—albeit not in all—studies endogenous markers showed prognostic significance for patient outcome. The prognostic relevance of exogenous markers, however, appears to be limited. Noninvasive assessment of hypoxia using imaging techniques can be achieved with PET or SPECT detection of radiolabeled tracers or with MRI techniques (e.g., BOLD). Clinical experience with these methods regarding patient prognosis is so far only limited. In the clinical studies performed up until now, the lack of standardized treatment protocols, inconsistencies of the endpoints characterizing the oxygenation status and methodological differences (e.g., different immunohistochemical staining procedures) may compromise the power of the prognostic parameter used.

negative: Isolated liver perfusion for non-resectable liver tumours: a review. Many treatments have been proposed for non-resectable primary or secondary hepatic cancer but the results have generally been disappointing. Isolated Hepatic Perfusion (IHP) was first attempted four decades ago but it gained acceptance only recently, after spectacular tumour responses were obtained by isolated limb perfusion with melphalan and tumour necrosis factor (TNF) for melanomas and sarcomas. Surgical isolation of the liver is a technically demanding operation that allows the safe administration of high doses of chemotherapeutics and TNF. Percutaneous techniques using balloon occlusion catheters are simpler but result in higher leakage rates from the perfusion circuit into the systemic circulation. Several phase I-II trials indicate that IHP can yield high tumour response rates, even when there is resistance to systemic chemotherapy. However, no significant advantage in overall survival has been demonstrated so far. IHP offers unique pharmacokinetic advantages for locoregional chemotherapy and biotherapy. It might also allow gene therapy with limited systemic exposure and toxicity. At present, IHP nevertheless remains an experimental treatment modality which should therefore be used in controlled trials only.

negative: Optogenetics reveal delayed afferent synaptogenesis on grafted human-induced pluripotent stem cell-derived neural progenitors. Reprogramming of somatic cells into pluripotency stem cell state has opened new opportunities in cell replacement therapy and disease modeling in a number of neurological disorders. It still remains unknown, however, to what degree the grafted human-induced pluripotent stem cells (hiPSCs) differentiate into a functional neuronal phenotype and if they integrate into the host circuitry. Here, we present a detailed characterization of the functional properties and synaptic integration of hiPSC-derived neurons grafted in an in vitro model of hyperexcitable epileptic tissue, namely organotypic hippocampal slice cultures (OHSCs), and in adult rats in vivo. The hiPSCs were first differentiated into long-term self-renewing neuroepithelial stem (lt-NES) cells, which are known to form primarily GABAergic neurons. When differentiated in OHSCs for 6 weeks, lt-NES cell-derived neurons displayed neuronal properties such as tetrodotoxin-sensitive sodium currents and action potentials (APs), as well as both spontaneous and evoked postsynaptic currents, indicating functional afferent synaptic inputs. The grafted cells had a distinct electrophysiological profile compared to host cells in the OHSCs with higher input resistance, lower resting membrane potential, and APs with lower amplitude and longer duration. To investigate the origin of synaptic afferents to the grafted lt-NES cell-derived neurons, the host neurons were transduced with Channelrhodopsin-2 (ChR2) and optogenetically activated by blue light. Simultaneous recordings of synaptic currents in grafted lt-NES cell-derived neurons using whole-cell patch-clamp technique at 6 weeks after grafting revealed limited synaptic connections from host neurons. Longer differentiation times, up to 24 weeks after grafting in vivo, revealed more mature intrinsic properties and extensive synaptic afferents from host neurons to the lt-NES cell-derived neurons, suggesting that these cells require extended time for differentiation/maturation and synaptogenesis. However, even at this later time point, the grafted cells maintained a higher input resistance. These data indicate that grafted lt-NES cell-derived neurons receive ample afferent input from the host brain. Since the lt-NES cells used in this study show a strong propensity for GABAergic differentiation, the host-to-graft synaptic afferents may facilitate inhibitory neurotransmitter release, and normalize hyperexcitable neuronal networks in brain diseases, for example, such as epilepsy.

negative: Beta adrenergic blockade decreases the immunomodulatory effects of social disruption stress During physiological or psychological stress, catecholamines produced by the sympathetic nervous system (SNS) regulate the immune system. Previous studies report that the activation of β-adrenergic receptors (βARs) mediates the actions of catecholamines and increases pro-inflammatory cytokine production in a number of different cell types. The impact of the SNS on the immune modulation of social defeat has not been examined. The following studies were designed to determine whether SNS activation during social disruption stress (SDR) influences anxiety-like behavior as well as the activation, priming, and glucocorticoid resistance of splenocytes after social stress. CD-1 mice were exposed to one, three, or six cycles of SDR and HPLC analysis of the plasma and spleen revealed an increase in catecholamines. After six cycles of SDR the open field test was used to measure behaviors characteristic of anxiety and indicated that the social defeat induced increase in anxiety-like behavior was blocked by pre-treatment with the β-adrenergic antagonist propranolol. Pre-treatment with the β-adrenergic antagonist propranolol did not significantly alter corticosterone levels indicating no difference in activation of the hypothalamic-pituitary-adrenal axis. In addition to anxiety-like behavior the SDR induced splenomegaly and increase in plasma IL-6, TNFα, and MCP-1 were each reversed by pre-treatment with propranolol. Furthermore, flow cytometric analysis of cells from propranolol pretreated mice reduced the SDR-induced increase in the percentage of CD11b(+) splenic macrophages and significantly decreased the expression of TLR2, TLR4, and CD86 on the surface of these cells. In addition, supernatants from 18h LPS-stimulated ex vivo cultures of splenocytes from propranolol-treated SDR mice contained less IL-6. Likewise propranolol pre-treatment abrogated the glucocorticoid insensitivity of CD11b(+) cells ex vivo when compared to splenocytes from SDR vehicle-treated mice. Together, this study demonstrates that the immune activation and priming effects of SDR result, in part, as a consequence of SNS activation.

negative: Evaluation of oxidative status and depression-like responses in Brown Norway rats with acute myeloid leukemia It has been proved that oxidative stress increases when leukemia is accompanied by depression. This fact may indicate the role of oxidative stress in the development of depression in cancer patients. The aim of this study was to determine whether the acute myeloid leukemia of Brown Norway rats, which is accompanied by oxidative stress, evoked behavioral and receptor changes resembling alterations characteristic of rat models of depression. The rats were divided into two groups: leukemic rats and healthy control. Leukemia was induced through intraperitoneal injection of 10(7) promyelocytic leukemia cells to the Brown Norway rats. Depression-like behavior was evaluated in the forced swim test at 30 or 34 days after leukemic cells injection. The rats were killed after the evaluation and the spleen, brain cortex and hippocampus were excised. The red-ox state was assessed in homogenates of tissues by measuring total glutathione (GSH) content, the ferric ion reducing ability of plasma (FRAP) level, expression of heme oxygenase-1 (HO-1), biliverdin reductase (BvR) and ferritin mRNA, superoxide dismutase (SOD) activity, as well as malondialdehyde (MDA) concentration. Radioligand binding assay was used to assess of the effect of leukemia on cortical receptors. Leukemic cells were identified using RM-124 antibody by FACS Calibur flow cytometry. Leukemia influenced locomotory activity as well as forced swim test behavior in a 34-day series of experiments. Signs of oxidative stress in leukemic rats were observed in each examined stage of leukemia development. The FRAP values and glutathione contents, were significantly lowered whereas HO-1 mRNA expression, and malonodialdehyde concentrations were significantly increased in the spleen and brain structures of leukemic rats in comparison with the healthy controls. A significant increase in the potency of glycine to displace [(3)H]L-689,560 from the strychnine-insensitive glycine site of the N-methyl-D-aspartic (NMDA) receptors receptor complex in cortical homogenates of the leukemic rats in 30- and 34-day experimental series was observed in comparison with the control. Upregulation of 5-HT(2A) receptors was observed in rat cortex after 30 days of leukemia development but not in 34-days series compared with the control. It is concluded that disturbances in antioxidant system in brain cortex were accompanied by an activation of glycine sites of the NMDA receptor complex, regardless of stage of leukemia development, which are characteristic of model of depression. Findings of our study demonstrate the link between glutamatergic activity, oxidative stress and leukemia.

negative: Advances in techniques of testing mycobacterial drug sensitivity, and the use of sensitivity tests in tuberculosis control programmes. In a paper arising out of an informal international consultation of specialists in the bacteriology of tuberculosis held in 1961, an attempt was made to formulate criteria, and specify technical procedures, for reliable tests of sensitivity (the absolute-concentration method, the resistance-ratio method and the proportion method) to the 3 main antituberculosis drugs (isoniazid, streptomycin and p-aminosalicylic acid). Seven years later, a further consultation was held to review the latest developments in the field and to suggest how sensitivity tests might be put to practical use in tuberculosis control programmes. The participants reached agreement on how to define drug sensitivity and resistance, and stressed the importance of using a discrimination approach to the calibration of sensitivity tests. Their views are contained in the present paper, which also includes descriptions of the sensitivity tests used by the Medical Research Council of Great Britain for first- and second-line drugs (minimal inhibitory concentration and resistance-ratio methods), the two main variants of the proportion method developed by the Institut Pasteur, Paris, and a method for calibrating sensitivity tests.

negative: Protection from olanzapine-induced metabolic toxicity in mice by acetaminophen and tetrahydroindenoindole Objective:In mice and in humans, treatment with the second-generation antipsychotic drug olanzapine (OLZ) produces excessive weight gain, adiposity and secondary metabolic complications, including loss of glucose and insulin homeostasis. In mice consuming a high-fat (HF) diet, a similar phenotype develops, which is inhibited by the analgesic acetaminophen (APAP) and by the antioxidant tetrahydroindenoindole (THII). Therefore, we examined the ability of APAP and THII to prevent metabolic changes in mice receiving OLZ.Design and Measurement:C57BL/6J mice received either a normal diet or a HF diet, and were administered daily dosages of OLZ (3 mg kg−1 body weight), alone or with APAP (30 mg kg−1 body weight) or THII (4.5 mg kg−1 body weight), for 10 weeks. Parameters of body composition and metabolism, including glucose and insulin homeostasis and oxidative stress, were examined. Results:OLZ treatment doubled the HF diet-induced increases in body weight and percent body fat. These increases were partially prevented by both APAP and THII, although food consumption was constant in all groups. The THII protection was associated with an increase in whole body and mitochondrial respiration. OLZ also exacerbated, and both APAP and THII prevented, HF diet-induced loss of glucose tolerance and insulin resistance. As increased body fat promotes insulin resistance by a pathway involving oxidative stress, we evaluated production of reactive oxygen and lipid peroxidation in white adipose tissue (WAT). HF diet caused an increase in lipid peroxidation, NADPH-dependent O2 uptake and H2O2 production, which were further exacerbated by OLZ. APAP, THII and the NADPH oxidase inhibitor, diphenyleneiodonium chloride, each abolished oxidative stress in WAT.Conclusions:We conclude that both APAP and THII intervene in the development of obesity and metabolic complications associated with OLZ treatment.

negative: Examining BCL-2 family function with large unilamellar vesicles. The BCL-2 (B cell CLL/Lymphoma) family is comprised of approximately twenty proteins that collaborate to either maintain cell survival or initiate apoptosis(1). Following cellular stress (e.g., DNA damage), the pro-apoptotic BCL-2 family effectors BAK (BCL-2 antagonistic killer 1) and/or BAX (BCL-2 associated X protein) become activated and compromise the integrity of the outer mitochondrial membrane (OMM), though the process referred to as mitochondrial outer membrane permeabilization (MOMP)(1). After MOMP occurs, pro-apoptotic proteins (e.g., cytochrome c) gain access to the cytoplasm, promote caspase activation, and apoptosis rapidly ensues(2). In order for BAK/BAX to induce MOMP, they require transient interactions with members of another pro-apoptotic subset of the BCL-2 family, the BCL-2 homology domain 3 (BH3)-only proteins, such as BID (BH3-interacting domain agonist)(3-6). Anti-apoptotic BCL-2 family proteins (e.g., BCL-2 related gene, long isoform, BCL-xL; myeloid cell leukemia 1, MCL-1) regulate cellular survival by tightly controlling the interactions between BAK/BAX and the BH3-only proteins capable of directly inducing BAK/BAX activation(7,8). In addition, anti-apoptotic BCL-2 protein availability is also dictated by sensitizer/de-repressor BH3-only proteins, such as BAD (BCL-2 antagonist of cell death) or PUMA (p53 upregulated modulator of apoptosis), which bind and inhibit anti-apoptotic members(7,9). As most of the anti-apoptotic BCL-2 repertoire is localized to the OMM, the cellular decision to maintain survival or induce MOMP is dictated by multiple BCL-2 family interactions at this membrane. Large unilamellar vesicles (LUVs) are a biochemical model to explore relationships between BCL-2 family interactions and membrane permeabilization(10). LUVs are comprised of defined lipids that are assembled in ratios identified in lipid composition studies from solvent extracted Xenopus mitochondria (46.5% phosphatidylcholine, 28.5% phosphatidylethanoloamine, 9% phosphatidylinositol, 9% phosphatidylserine, and 7% cardiolipin)(10). This is a convenient model system to directly explore BCL-2 family function because the protein and lipid components are completely defined and tractable, which is not always the case with primary mitochondria. While cardiolipin is not usually this high throughout the OMM, this model does faithfully mimic the OMM to promote BCL-2 family function. Furthermore, a more recent modification of the above protocol allows for kinetic analyses of protein interactions and real-time measurements of membrane permeabilization, which is based on LUVs containing a polyanionic dye (ANTS: 8-aminonaphthalene-1,3,6-trisulfonic acid) and cationic quencher (DPX: p-xylene-bis-pyridinium bromide)(11). As the LUVs permeabilize, ANTS and DPX diffuse apart, and a gain in fluorescence is detected. Here, commonly used recombinant BCL-2 family protein combinations and controls using the LUVs containing ANTS/DPX are described.

negative: Vegetarian diet improves insulin resistance and oxidative stress markers more than conventional diet in subjects with Type 2 diabetes AIMS The aim of this study was to compare the effects of calorie-restricted vegetarian and conventional diabetic diets alone and in combination with exercise on insulin resistance, visceral fat and oxidative stress markers in subjects with Type 2 diabetes. METHODS A 24-week, randomized, open, parallel design was used. Seventy-four patients with Type 2 diabetes were randomly assigned to either the experimental group (n = 37), which received a vegetarian diet, or the control group (n = 37), which received a conventional diabetic diet. Both diets were isocaloric, calorie restricted (-500 kcal/day). All meals during the study were provided. The second 12 weeks of the diet were combined with aerobic exercise. Participants were examined at baseline, 12 weeks and 24 weeks. Primary outcomes were: insulin sensitivity measured by hyperinsulinaemic isoglycaemic clamp; volume of visceral and subcutaneous fat measured by magnetic resonance imaging; and oxidative stress measured by thiobarbituric acid reactive substances. Analyses were by intention to treat. RESULTS Forty-three per cent of participants in the experimental group and 5% of participants in the control group reduced diabetes medication (P < 0.001). Body weight decreased more in the experimental group than in the control group [-6.2 kg (95% CI -6.6 to -5.3) vs. -3.2 kg (95% CI -3.7 to -2.5); interaction group × time P = 0.001]. An increase in insulin sensitivity was significantly greater in the experimental group than in the control group [30% (95% CI 24.5-39) vs. 20% (95% CI 14-25), P = 0.04]. A reduction in both visceral and subcutaneous fat was greater in the experimental group than in the control group (P = 0.007 and P = 0.02, respectively). Plasma adiponectin increased (P = 0.02) and leptin decreased (P = 0.02) in the experimental group, with no change in the control group. Vitamin C, superoxide dismutase and reduced glutathione increased in the experimental group (P = 0.002, P < 0.001 and P = 0.02, respectively). Differences between groups were greater after the addition of exercise training. Changes in insulin sensitivity and enzymatic oxidative stress markers correlated with changes in visceral fat. CONCLUSIONS A calorie-restricted vegetarian diet had greater capacity to improve insulin sensitivity compared with a conventional diabetic diet over 24 weeks. The greater loss of visceral fat and improvements in plasma concentrations of adipokines and oxidative stress markers with this diet may be responsible for the reduction of insulin resistance. The addition of exercise training further augmented the improved outcomes with the vegetarian diet.

negative: Mechanisms linking obesity to insulin resistance and type 2 diabetes Obesity is associated with an increased risk of developing insulin resistance and type 2 diabetes. In obese individuals, adipose tissue releases increased amounts of non-esterified fatty acids, glycerol, hormones, pro-inflammatory cytokines and other factors that are involved in the development of insulin resistance. When insulin resistance is accompanied by dysfunction of pancreatic islet β-cells — the cells that release insulin — failure to control blood glucose levels results. Abnormalities in β-cell function are therefore critical in defining the risk and development of type 2 diabetes. This knowledge is fostering exploration of the molecular and genetic basis of the disease and new approaches to its treatment and prevention.

negative: Predictors of survival after acute paraquat poisoning. Acute paraquat poisoning is often fatal. Many studies have investigated successful treatment modalities, but no standard treatment yet exists. The purpose of this study was to determine the predictors of survival after acute paraquat poisoning in 602 patients. The paraquat exposure was assessed based on the amount of ingested paraquat and a semiquantitative measure of the urine level of paraquat. Initial clinical parameters including vital signs, hemoglobin, white-blood-cell count, pH, PaCO2, PaO2, blood urea nitrogen, creatinine, aspartate aminotransferase, alanine aminotransferase, total bilirubin, amylase, and glucose were obtained at the time of arrival at the emergency room. Outcomes after acute paraquat poisoning were categorized as survivors and nonsurvivors. Multiple logistic regression analysis was applied to assess the predictors of survival after acute paraquat poisoning. Some patients (55.5%) survived after oral ingestion of paraquat, whereas all those exposed to paraquat percutaneous or inhalational route survived. The amount of paraquat (24.5% concentrate of 1,1'-dimethyl-4,4'-bipyridium dichloride) ingested was 45.6 +/- 74.1 mL (mean +/- SD). In addition to degree of paraquat exposure, survival after acute paraquat poisoning was associated with age, respiratory rate, pH, PaCO2, hemoglobin, white-blood-cell count, blood urea nitrogen, amylase, and the number of failed organs in multiple logistic regression analysis. In conclusion, young age, percutaneous or inhalational route, exposure to less paraquat, and lesser degrees of leukocytosis, acidosis, and renal, hepatic, and pancreatic failures on admission are good prognostic factors of survival after acute paraquat poisoning.

negative: Proteomic approach to characterize biochemistry of meat quality defects. Proteomics can be used to characterize quality defects including pale, soft, and exudative (PSE) meat (pork and poultry), woody broiler breast meat, reddish catfish fillets, meat toughness, and beef myoglobin oxidation. PSE broiler meat was characterized by 15 proteins that differed in abundance in comparison to normal broiler breast meat, and eight proteins were differentially expressed in woody breast meat in comparison to normal breast meat. Hemoglobin was the only protein that was differentially expressed between red and normal catfish fillets. However, inducing low oxygen and/or heat stress conditions to catfish fillets did not lead to the production of red fillets. Proteomic data provided information pertaining to the protein differences that exist in meat quality defects. However, these data need to be evaluated in conjunction with information pertaining to genetics, nutrition, environment of the live animal, muscle to meat conversion, meat quality analyses and sensory attributes to understand causality, protein biomarkers, and ultimately how to prevent quality defects.

negative: Influence of smoking cessation after diagnosis of early stage lung cancer on prognosis: systematic review of observational studies with meta-analysis OBJECTIVE To systematically review the evidence that smoking cessation after diagnosis of a primary lung tumour affects prognosis. DESIGN Systematic review with meta-analysis. DATA SOURCES CINAHL (from 1981), Embase (from 1980), Medline (from 1966), Web of Science (from 1966), CENTRAL (from 1977) to December 2008, and reference lists of included studies. STUDY SELECTION Randomised controlled trials or observational longitudinal studies that measured the effect of quitting smoking after diagnosis of lung cancer on prognostic outcomes, regardless of stage at presentation or tumour histology, were included. DATA EXTRACTION Two researchers independently identified studies for inclusion and extracted data. Estimates were combined by using a random effects model, and the I(2) statistic was used to examine heterogeneity. Life tables were used to model five year survival for early stage non-small cell lung cancer and limited stage small cell lung cancer, using death rates for continuing smokers and quitters obtained from this review. RESULTS In 9/10 included studies, most patients studied were diagnosed as having an early stage lung tumour. Continued smoking was associated with a significantly increased risk of all cause mortality (hazard ratio 2.94, 95% confidence interval 1.15 to 7.54) and recurrence (1.86, 1.01 to 3.41) in early stage non-small cell lung cancer and of all cause mortality (1.86, 1.33 to 2.59), development of a second primary tumour (4.31, 1.09 to 16.98), and recurrence (1.26, 1.06 to 1.50) in limited stage small cell lung cancer. No study contained data on the effect of quitting smoking on cancer specific mortality or on development of a second primary tumour in non-small cell lung cancer. Life table modelling on the basis of these data estimated 33% five year survival in 65 year old patients with early stage non-small cell lung cancer who continued to smoke compared with 70% in those who quit smoking. In limited stage small cell lung cancer, an estimated 29% of continuing smokers would survive for five years compared with 63% of quitters on the basis of the data from this review. CONCLUSIONS This review provides preliminary evidence that smoking cessation after diagnosis of early stage lung cancer improves prognostic outcomes. From life table modelling, the estimated number of deaths prevented is larger than would be expected from reduction of cardiorespiratory deaths after smoking cessation, so most of the mortality gain is likely to be due to reduced cancer progression. These findings indicate that offering smoking cessation treatment to patients presenting with early stage lung cancer may be beneficial.

negative: Key role for IL-21 in experimental autoimmune uveitis. IL-21 is a pleiotropic type 1 cytokine that shares the common cytokine receptor γ-chain, γ(c), with IL-2, IL-4, IL-7, IL-9, and IL-15. IL-21 is most homologous to IL-2. These cytokines are encoded by adjacent genes, but they are functionally distinct. Whereas IL-2 promotes development of regulatory T cells and confers protection from autoimmune disease, IL-21 promotes differentiation of Th17 cells and is implicated in several autoimmune diseases, including type 1 diabetes and systemic lupus erythematosus. However, the roles of IL-21 and IL-2 in CNS autoimmune diseases such as multiple sclerosis and uveitis have been controversial. Here, we generated Il21-mCherry/Il2-emGFP dual-reporter transgenic mice and showed that development of experimental autoimmune uveitis (EAU) correlated with the presence of T cells coexpressing IL-21 and IL-2 into the retina. Furthermore, Il21r(-/-) mice were more resistant to EAU development than wild-type mice, and adoptive transfer of Il21r(-/-) T cells induced much less severe EAU, underscoring the need for IL-21 in the development of this disease and suggesting that blocking IL-21/γ(c)-signaling pathways may provide a means for controlling CNS auto-inflammatory diseases.

negative: Global and regional risk of disabling sequelae from bacterial meningitis: a systematic review and meta-analysis. Few data sources are available to assess the global and regional risk of sequelae from bacterial meningitis. We aimed to estimate the risks of major and minor sequelae caused by bacterial meningitis, estimate the distribution of the different types of sequelae, and compare risk by region and income. We systematically reviewed published papers from 1980 to 2008. Standard global burden of disease categories (cognitive deficit, bilateral hearing loss, motor deficit, seizures, visual impairment, hydrocephalus) were labelled as major sequelae. Less severe, minor sequelae (behavioural problems, learning difficulties, unilateral hearing loss, hypotonia, diplopia), and multiple impairments were also included. 132 papers were selected for inclusion. The median (IQR) risk of at least one major or minor sequela after hospital discharge was 19.9% (12.3-35.3%). The risk of at least one major sequela was 12.8% (7.2-21.1%) and of at least one minor sequela was 8.6% (4.4-15.3%). The median (IQR) risk of at least one major sequela was 24.7% (16.2-35.3%) in pneumococcal meningitis; 9.5% (7.1-15.3%) in Haemophilus influenzae type b (Hib), and 7.2% (4.3-11.2%) in meningococcal meningitis. The most common major sequela was hearing loss (33.9%), and 19.7% had multiple impairments. In the random-effects meta-analysis, all-cause risk of a major sequela was twice as high in the African (pooled risk estimate 25.1% [95% CI 18.9-32.0%]) and southeast Asian regions (21.6% [95% CI 13.1-31.5%]) as in the European region (9.4% [95% CI 7.0-12.3%]; overall I(2)=89.5%, p<0.0001). Risks of long-term disabling sequelae were highest in low-income countries, where the burden of bacterial meningitis is greatest. Most reported sequelae could have been averted by vaccination with Hib, pneumococcal, and meningococcal vaccines.

negative: Origin of nitrite and nitrate in nasal and exhaled breath condensate and relation to nitric oxide formation. BACKGROUND Raised concentrations of nitrate and nitrite have been found in exhaled breath condensate (EBC) in airway disease, and it has been postulated that this reflects increased nitric oxide (NO) metabolism. However, the chemical and anatomical origin of nitrate and nitrite in the airways has not yet been sufficiently studied. METHODS The fraction of exhaled NO at an exhalation flow rate of 50 ml/s (FE(NO)) and nitrite and nitrate in EBC, nasal condensate, and saliva were measured in 17 tracheostomised and 15 non-tracheostomised subjects, all of whom were non-smokers without respiratory disease. Tracheal and oral samples were taken from the tracheostomised subjects and nasal (during velum closure) and oral samples from the non-tracheostomised subjects. Measurements were performed before and after sodium nitrate ingestion (10 mg/kg) and use of antibacterial mouthwash (chlorhexidine 0.2%). RESULTS In tracheostomised subjects oral FE(NO) increased by 90% (p<0.01) while tracheal FE(NO) was not affected 60 minutes after nitrate ingestion. Oral EBC nitrite levels were increased 23-fold at 60 minutes (p<0.001) whereas the nitrite levels in tracheal EBC showed only a minor increase (fourfold, p<0.05). Nitrate was increased the same amount in oral and tracheal EBC at 60 minutes (2.5-fold, p<0.05). In non-tracheostomised subjects oral FE(NO) and EBC nitrite increased after nitrate ingestion and after chlorhexidine mouthwash they approached baseline levels again (p<0.001). Nasal NO, nitrate, and nitrite were not affected by nitrate intake or mouthwash. At baseline, mouthwash with deionised water did not affect nitrite in oral EBC or saliva, whereas significant reductions were seen after antibacterial mouthwash (p<0.05 and p<0.001, respectively). CONCLUSIONS Besides the salivary glands, plasma nitrate is taken up by the lower airways but not the nasal airways. Nitrate levels in EBC are thus influenced by dietary intake. Nitrate is reduced to nitrite by bacterial activity which takes place primarily in the oropharyngeal tract of healthy subjects. Only oropharyngeal nitrite seems to contribute to exhaled NO in non-inflamed airways, and there is also a substantial contribution of nitrite from the oropharyngeal tract during standard collection of EBC.

negative: A multiple indicators multiple causes model of late-life depression in Latin American countries BACKGROUND The Euro-D depression scale consists of symptom clusters that may be differentially related to demographic and cognitive characteristics in older adults. This hypothesis needs further investigation and the role of measurement bias on substantive conclusions remains to be established. METHOD The study sample comprised 10,405 community-dwelling older adults from six Latin American countries. We applied a Multiple Indicators Multiple Causes (MIMIC) model for a concurrent investigation of measurement bias and of the association between Euro-D symptom clusters and background variables. RESULTS The factorial validity of Euro-D, with a two-dimensional structure--affective suffering and motivation disturbance, was consistently supported in all countries. Although complete measurement invariance could not be assumed across countries, measurement bias was minor. Both Euro-D factors were unrelated to age, but related to gender, as well as to impairment in memory and verbal fluency. Gender differences were larger for affective suffering than for motivation disturbance, whereas differences in verbal fluency impairment were more strongly related to motivation disturbance. LIMITATIONS Our analytic strategies could only examine invariance at the level of indicator thresholds. The generalisability of current findings needs to be examined in clinical populations. A wider set of cognitive tests is needed. We did not examine the compositional factors that could have accounted for the variation in Euro-D scores across countries, as this was beyond the aims of the paper. CONCLUSION The current study adds evidence for the construct validity of Euro-D and for the possible differential association of depression symptom-clusters with gender and verbal fluency in older adults. An understanding of the heterogeneity of late-life depression may carry clinical implications for the diagnosis and treatment of depression in old age.