Experimental Gerontology 39 (2004) 263–268

in the SHC1 gene and longevity in humans

Simon P. , Diana van Jeroen , Suzan van , b a,b b a Marian Beekman , Bernd W. Brandt , P. Eline Slagboom , Rudi G.J. Westendorp , 1 on behalf of the ‘Long Life’ study group

aSection of Gerontology and Geriatrics, Department of General Internal Medicine, Leiden University Medical Center, P.O. Box 9503, RC Leiden 2300, The Netherlands bSection of Molecular Epidemiology, Department of Medical Statistics, Leiden University Medical Center, P.O. Box 9600, RA Leiden 2300, The Netherlands

Received 2 July 2003; received in revised form 30 September 2003; accepted 7 October 2003

Abstract

Mice in which the specific region of the SHC gene is deleted live 30% longer without apparent disease. These mice have lower levels of oxidative stress and apoptosis, both of which have been linked to old age survival in man. This makes SHC1 an important candidate gene for longevity in humans. We found no variations in the p66 specific region of the SHC1 gene in 30 young and 30 extreme long-lived subjects. Thus in man, no common sequence variations occur in p66 specific region of the SHC1 gene. In two independent cohorts of respectively 730 and 563 subjects aged 85 and over, we tested the only known non-synonymous polymorphism, Met410Val, for association with longevity using a prospective follow-up design. In the first cohort, we found increasing valine allele frequency in three strata of increasing age at death (2.8–5.2%). Moreover, compared to Met/Met carriers, mortality rate was a factor of 0.71 (95% CI 0.45–1.13) reduced for Met/Val carriers in the combined cohorts, with similar risk estimates in both cohorts. Low valine allele frequency resulted, however, in low power to detect statistical significance. These data suggest that an association between the Met410Val polymorphism and longevity in humans may exist.

Keywords: Longevity; Polymorphism; Insulin signaling; Human; Oxidative stress; Apoptosis

abnormalities (Migliaccio et al., 1999). Cells derived from p66SHC2/2 mice show increased resistance to apoptosis in reaction to oxidative stress (Migliaccio et al., 1999), and intracellular oxidant levels were found to be decreased (Nemoto and Finkel, 2002). Apoptosis (Campisi, 2003) and reactive oxygen species (Martin et al., 1996) have been suggested to play a role in human longevity. Recently, it was shown in mice fed a high-fat diet that deletion of the p66SHC gene reduces vascular cell apoptosis and early atherogenesis (Napoli et al., 2003). Taken together, these findings implicate the p66SHC1 gene as an important candidate gene for human longevity.

1. Introduction

The SHC gene, named after its Src and Collagen homologous regions, has been related to longevity in mice, but the role of SHC1 gene variants with respect to human longevity has not yet been investigated. Mice in which the p66SHC specific region of the SHC gene is knocked out (p66SHC2/2) have a higher resistance to paraquat, which causes oxidative stress, and live up to 30% longer in the absence of other phenotypic

The human SHC1 adaptor protein is encoded by one gene but has three isoforms: p66SHC1, p52SHC1 and p46SHC1. All three are adaptor proteins in the insulin-signaling pathway, but their downstream effects differ (Migliaccio et al., 1997). Both p52SHC1 and p46SHC1 are associated with MAPK signaling and are highly conserved throughout evolution;

E-mail address: d.van_heemst@lumc.nl (D. van Heemst). 1 The ‘Long Life’ study group. A. Ayrinhac, E.A. Baldal, M. Beekman, G.J. Blauw, D.I. Boomsma, P.M. Brakefield, B.W. Brandt, R. Bijlsma, S. van Gerwen, D. van Heemst, B.T. Heijmans, J.C. van Houwelingen, D.L. Knook, I. Meulenbelt, P.H.E.M. de Meijer, S.P. Mooijaart, J. Pijpe, M. Schoenmaker, P.E. Slagboom, R.G.J. Westendorp, L.P.W.G.M. van de Zande and B.J. Zwaan.

0531-5565/$ - see front matter q 2003 Elsevier Inc. All rights reserved. doi:10.1016/j.exger.2003.10.001

S.P. Mooijaart et al. / Experimental Gerontology 39 (2004) 263–268

Met*!°val       36 138I s I | yCH2 PTB CHI SH2gt Met?Val; | y3l7IPTB CHI SH2Met?>°Val| y"PTB CHI SH2     p66p52p46

Fig. 1. The SHC1 protein isoforms. The p66SHC1 protein is 583 amino acids long and is translated from the long transcript of the SHC1 gene. The p52 and p46 isoforms are 473 and 428 amino acids long, respectively, and are translated from both the long and the short transcript of the gene. The position of the methionine to valine variant is shown for the different proteins. Serine 36 (S36) in p66SHC1 is phosphorylated in reaction to oxidative damage (Le et al., 2001). Serine 138 (S138) in p66SHC1 is phosphorylated in reaction to insulin binding, resulting in down-regulation of SHC1 (Faisal et al., 2002). Tyrosine residue at position 427 (Y427) of p66SHC1 is phosphorylated upon growth factor stimulation, causing inhibition of the MAPK pathway (Migliaccio et al., 1997) CH2, collagen homology domain 2; PTB, phosphothyrosine binding domain; CH1, collagen homology domain 1; SH2, Src homology domain 2.

2. Methods

p66SHC1 signaling is associated with apoptosis and is only seen in vertebrates (Luzi et al., 2000). The SHC1 gene contains one known coding variation, which corresponds to Met225Val in the p46 isoform, Met300Val in the p52 isoform and to Met410Val in the p66 isoform (Fig. 1) (Almind et al., 1999). No association of the Met300Val variation was found with birth weight and length, impaired insulin secretion, insulin resistance, and type 2 Diabetes Mellitus (Almind et al., 1999). However, these observations do not exclude the possibility that the variant specifically affects the function of p66SHC1 and not of p46SHC1 and p52SHC1. Neither the p66SHC1 specific part of the SHC1 gene nor its upstream promoter region have been investigated for variations in humans.

2.1. Subject selection