Sex Difference and Interaction of SIRT1 and FOXO3 Candidate Longevity Genes on Life Expectancy: A 10-year Prospective Longitudinal Cohort Study

SIRT1 and FOXO3 are both associated with longevity. Molecular biology research in many organisms (yeast, nematode worm Caenorhabditis elegans, and mice mammalian models) shows SIRT1 acts on the FOXO family of forkhead transcription factors to respond to oxidative stress better, shifting processes away from cell death towards stress resistance. Human population studies need epidemiologic evidence. We used an open cohort of 3,166 community-dwelling participants in China with follow-up from 2008 to 2018. The mean age at baseline was 84.6 years. In 16,375 person-years of follow-up, there were 1,968 mortality events. SIRT1 and FOXO3 exhibited mendelian randomization as there was no correlation with each other and with baseline study population characteristics. Some SIRT1 and FOXO3 SNPs showed protective effects for mortality risk. The FOXO3 protective effect was stronger in females, and the SIRT1 protective effect was stronger in male study participants. We did not see evidence of a synergistic effect of being carriers of both SIRT1 and FOXO3.

Abstract P176: Genes That Increase Human Lifespan By Protecting Against Risk Of Death From Cardiometabolic Diseases

Further to our FOXO3 findings last year, we asked whether other longevity gene variants work by mitigating mortality risk from aging-related diseases. In a longitudinal study, 3,584 American men of Japanese ancestry from the Kuakini Honolulu Heart Program were followed from baseline (Exam 4, 1991-93) until Dec 31, 2019 (1% of men) or death (99%). At baseline, 2,512 subjects had either diabetes (n=1,010), hypertension (n=1,919) or coronary heart disease (CHD; n=738), and 1,072 lacked any cardiometabolic diseases (CMD). DNA samples for genotyping were obtained at baseline. Genotype frequencies of SNPs in MAP3K5 , PIK3R1 , GHR, CTGF , EGFR , FLT1 , SIRT5 and SIRT7 were compared between subjects with and without ageing-related diseases . In subjects with CMD, MAP3K5 rs2076260 longevity-associated genotypes CC and CC + TT were associated with longer lifespan (covariate-adjusted hazard ratio [HR] 1.23 [95% CI: 1.12-1.35, p= 2.5x10 -5 ] in a major allele homozygote model, and 1.22 [95% CI: 1.11-1.33, p= 1.10x10 -5 ] in a heterozygote disadvantage model) compared with CT . For diabetes, hypertension and CHD, HR p -values were 0.019, 0.00048, 0.093, and 0.0024, 0.00040, 0.0014, in each respective genetic model. For PIK3R1 , subjects with cardiovascular disease (CVD) having the longevity-associated genotypes TT / CC of SNP rs7709243 had survival curves similar to those of subjects without a CVD (HR 1.26 [95% CI, 1.14-1.39; p =0.0000043]). In contrast, survival curves of subjects with the CT genotype were significantly lower compared with survival curves of subjects without a CVD ( p =0.0000012 compared with TT / CC , and p =0.0000028 compared with CT ). For GHR SNP rs4130113 , in a heterozygote disadvantage model GG vs longevity-associated AG genotype was associated with reduced mortality risk from hypertension (HR 1.23 [95% CI, 0.94-1.41; p =0.0041]). Men without CVD showed no association of longevity-associated genotype with lifespan. For each gene, men without the disease outlived men with disease ( p < 10 -6 ), but genotype had no effect on lifespan. In conclusion, for MAP3K5 , PIK3R1 and GHR , but not other longevity genes, longevity genotype increases lifespan only in individuals who have CMD, CVD or hypertension, likely by protection against disease-related cellular stress.

Platelet Microparticles Accelerate Proliferation and Growth of Mesenchymal Stem Cells through Longevity-Related Genes

Background: Due to their self-renewal and differentiation ability, the mesenchymal stem cells (MSCs) have been studied extensively. However, the MSCs lifespan is restricted; they undergo several divisions in vitro that cause several alternations in cellular features and relatively lessens their application. Thus, this study was aimed to assess the effect of platelet-derived microparticles (PMPs), a valuable source of proteins, microRNAs (miRNAs), and growth factors, on the expression of hTERT, c-MYC, p16, p53, and p21 as the most important aging and cell longevity genes alongside with population doubling time (PDT) of PMP-treated cells in comparison to a control group. Methods: Umbilical cord MSCs (UC-MSCs) were used in this study, whereby they reached a confluency of 30%. MSCs were treated by PMPs (50 µg/mL), and then, PDT was determined for both groups. Quantitative expression of hTERT, c-MYC, p16, p53, and p21 was examined through quantitative real-time PCR at various intervals (i.e. after five and thirty days as well as freezing-thawing process). Results: Our results demonstrated that the treated group had a shorter PDT in comparison to the control group (P<0.050). The real-Time PCR data also indicated that PMPs were able to remarkably up-regulate hTERT and c-MYC genes expression while down-regulating the expression of p16, p21, and p53 genes (P<0.050), especially following five days of treatment. Conclusion: According to these data, it appears that PMPs are a safe and effective candidate for prolonging the lifespan of UC-MSCs; however, further investigations are needed to corroborate this finding.

Positive selection and enhancer evolution shaped lifespan and body mass in great apes

Within primates, the great apes are outliers both in terms of body size and lifespan, since they include the largest and longest-lived species in the order. Yet, the molecular bases underlying such features are poorly understood. Here, we leveraged an integrated approach to investigate multiple sources of molecular variation across primates, focusing on ~1,550 genes previously described as tumor suppressors, oncogenes, ageing genes in addition to a novel Build of the CellAge database of cell-senescence genes (version 2), herein presented for the first time. Specifically, we analyzed dN/dS rates, positive selection, gene expression (RNA-seq) and gene regulation (ChIP-seq). By analyzing the correlation between dN/dS, maximum lifespan and body mass we identified 67 genes that in primates co-evolved with those traits. Further, we identified 6 genes, important for immunity, neurodevelopment and telomere maintenance (including TERF2), under positive selection in the great ape ancestor. RNA-seq data, generated from the liver of six species representing all the primate lineages, revealed that ~8% of the longevity genes are differentially expressed in apes relative to other primates. Importantly, by integrating RNA-seq with ChIP-seq for H3K27ac (which marks active enhancers), we show that the differentially expressed longevity genes are significantly more likely than expected to be located near a novel ape-specific enhancer. Moreover, these particular ape-specific enhancers are enriched for young transposable elements, and specifically SINE-Vntr-Alus (SVAs). In summary, we demonstrate that multiple evolutionary forces have contributed to the evolution of lifespan and body size in primates.

Publisher Correction: A meta-analysis of genome-wide association studies identifies multiple longevity genes

A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-22613-2

Molecular regulation of lifespan extension in fertile ant workers

The evolution of sociality in insects caused a divergence in lifespan between reproductive and non-reproductive castes. Ant queens can live for decades, while most workers survive only weeks to a few years. In most organisms, longevity is traded-off with reproduction, but in social insects, these two life-history traits are positively linked. Once fertility is induced in workers, e.g. by queen removal, worker lifespan increases. The molecular regulation of this positive link between fecundity and longevity and generally the molecular underpinnings of caste-specific senescence are not well understood. Here, we investigate the transcriptomic regulation of lifespan and reproduction in fat bodies of three worker groups in the ant Temnothorax rugatulus . In a long-term experiment, workers that became fertile in the absence of the queen showed increased survival and upregulation of genes involved in longevity and fecundity pathways. Interestingly, workers that re-joined their queen after months exhibited intermediate ovary development, but retained a high expression of longevity and fecundity genes. Strikingly, the queen's presence causes a general downregulation of genes in worker fat bodies. Our findings point to long-term consequences of fertility induction in workers, even after re-joining their queen. Moreover, we reveal longevity genes and pathways modulated during insect social evolution. This article is part of the theme issue ‘Ageing and sociality: why, when and how does sociality change ageing patterns?’

Cost-free lifespan extension via optimization of gene expression in adulthood aligns with the developmental theory of ageing

Ageing evolves because the force of selection on traits declines with age but the proximate causes of ageing are incompletely understood. The ‘disposable soma’ theory of ageing (DST) upholds that competitive resource allocation between reproduction and somatic maintenance underpins the evolution of ageing and lifespan. In contrast, the developmental theory of ageing (DTA) suggests that organismal senescence is caused by suboptimal gene expression in adulthood. While the DST predicts the trade-off between reproduction and lifespan, the DTA predicts that age-specific optimization of gene expression can increase lifespan without reproduction costs. Here we investigated the consequences for lifespan, reproduction, egg size and individual fitness of early-life, adulthood and post-reproductive onset of RNAi knockdown of five ‘longevity’ genes involved in key biological processes in Caenorhabditis elegans . Downregulation of these genes in adulthood and/or during post-reproductive period increases lifespan, while we found limited evidence for a link between impaired reproduction and extended lifespan. Our findings demonstrate that suboptimal gene expression in adulthood often contributes to reduced lifespan directly rather than through competitive resource allocation between reproduction and somatic maintenance. Therefore, age-specific optimization of gene expression in evolutionarily conserved signalling pathways that regulate organismal life histories can increase lifespan without fitness costs.

Exome-Wide Association Study Identifies FN3KRP and PGP as New Candidate Longevity Genes

Despite enormous research efforts, the genetic component of longevity has remained largely elusive. The investigation of common variants, mainly located in intronic or regulatory regions, has yielded only little new information on the heritability of the phenotype. Here, we performed a chip-based exome-wide association study investigating 62 488 common and rare coding variants in 1248 German long-lived individuals, including 599 centenarians and 6941 younger controls (age &lt; 60 years). In a single-variant analysis, we observed an exome-wide significant association between rs1046896 in the gene fructosamine-3-kinase-related-protein (FN3KRP) and longevity. Noteworthy, we found the longevity allele C of rs1046896 to be associated with an increased FN3KRP expression in whole blood; a database look-up confirmed this effect for various other human tissues. A gene-based analysis, in which potential cumulative effects of common and rare variants were considered, yielded the gene phosphoglycolate phosphatase (PGP) as another potential longevity gene, though no single variant in PGP reached the discovery p-value (1 × 10E−04). Furthermore, we validated the previously reported longevity locus cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1). Replication of our results in a French longevity cohort was only successful for rs1063192 in CDKN2B-AS1. In conclusion, we identified 2 new potential candidate longevity genes, FN3KRP and PGP which may influence the phenotype through their role in metabolic processes, that is, the reverse glycation of proteins (FN3KRP) and the control of glycerol-3-phosphate levels (PGP).