Longevity-Associated FOXO3 Genotype and its Impact on Coronary Artery Disease Mortality in Japanese, Whites, and Blacks: A Prospective Study of Three American Populations

Novel protective effect of the FOXO3 longevity genotype on mechanisms of cellular aging in Okinawans

The genetic association of FOXO3 genotypes with human longevity is well established, although the mechanism is not fully understood. We now report on the relationship of the FOXO3 longevity variant rs2802292 with telomere length, telomerase activity, FOXO3 expression, and inflammatory cytokine levels in men and women. In agreement with earlier work, the FOXO3 longevity variant conferred protection against telomere shortening of peripheral blood mononuclear cells from adults aged 55 years and older. This was accompanied by higher levels of telomerase activity in mononuclear cells for carriers of the longevity-associated FOXO3 G-allele of SNP rs2802292 (P = 0.015). FOXO3 mRNA expression increased slightly with age in both young (P = 0.02) and old (P = 0.08) G-allele carriers. Older female G-allele carriers displayed a modest decline in levels of pro-inflammatory cytokine IL-6 with age (P = 0.07). In contrast, older male G-allele carriers displayed an age-dependent increase in levels of anti-inflammatory cytokine IL-10 with age (P = 0.04). Thus, FOXO3 may act through several different pro-longevity mechanisms, which may differ by age and sex.

FOXO3A-short is a novel regulator of non-oxidative glucose metabolism associated with human longevity

Intronic single-nucleotide polymorphisms (SNPs) in FOXO3A are associated with human longevity. Currently, it is unclear how these SNPs alter FOXO3A functionality and human physiology, thereby influencing lifespan. Here, we identify a primate-specific FOXO3A transcriptional isoform, FOXO3A-Short (FOXO3A-S), encoding a major longevity-associated SNP, rs9400239 (C or T), within its 5' untranslated region. The FOXO3A-S mRNA is highly expressed in the skeletal muscle and has very limited expression in other tissues. We find that the rs9400239 variant influences the stability and functionality of the primarily nuclear protein(s) encoded by the FOXO3A-S mRNA. Assessment of the relationship between the FOXO3A-S polymorphism and peripheral glucose clearance during insulin infusion (Rd clamp) in a cohort of Danish twins revealed that longevity T-allele carriers have markedly faster peripheral glucose clearance rates than normal lifespan C-allele carriers. In vitro experiments in human myotube cultures utilizing overexpression of each allele showed that the C-allele represses glycolysis independently of PI3K signaling, while overexpression of the T-allele represses glycolysis only in a PI3K-inactive background. Supporting this finding inducible knockdown of the FOXO3A-S C-allele in cultured myotubes increases the glycolytic rate. We conclude that the rs9400239 polymorphism acts as a molecular switch which changes the identity of the FOXO3A-S-derived protein(s), which in turn alters the relationship between FOXO3A-S and insulin/PI3K signaling and glycolytic flux in the skeletal muscle. This critical difference endows carriers of the FOXO3A-S T-allele with consistently higher insulin-stimulated peripheral glucose clearance rates, which may contribute to their longer and healthier lifespans.

Identification of Biomarkers Associated With CD8+ T Cells in Coronary Artery Disease and Their Pan-Cancer Analysis

Purpose

To identify biomarkers associated with CD8+ T cells in coronary artery disease (CAD) and initially explore their potential role in the tumor immune microenvironment.

Materials and Methods

CAD-related datasets GSE12288, GSE34198, and GSE66360, were downloaded from the GEO database. First, GSVA was performed based on the GSE12288 dataset. Then WGCNA analysis was performed to identify the most relevant module and candidate hub gene for CD8+ T cells, followed by GO and KEGG analysis of this module. Secondly, the relationship between candidate hub genes and CD8+ T cells was verified using GSE34198 and GSE66360, which led to the identification of hub genes. The relationship of hub genes with CD8+ T cells in cancer was analyzed using the TIMER database. Methylation analysis of hub genes was performed using the DiseaseMeth database. CAD, pan-cancer, pan-cell lines, and pan-normal tissues, correlations between hub genes. In addition, potential drugs and TFs associated with hub genes were predicted, and the ceRNA network was constructed. Finally, GSEA was performed separately for hub genes.

Results

CAD was shown to be associated with immune response by GSVA analysis. WGCNA identified the blue module as most related to CD8+ T cells and identified nine candidate hub genes. The relevance of CAD to immunity was further confirmed by GO and KEGG analysis of the module. Two additional datasets validated and identified three hub genes (FBXO7, RAD23A, and MKRN1) that significantly correlated with CD8+ T cells. In addition, we found that hub genes were positively associated with CD8+ T cells in TGCT, THCA, and KICH cancers by our analysis. Moreover, the hub gene was differentially methylated. We also analyzed the correlation between hub genes in CAD, different cancers, different cell lines, and different normal tissues. The results of all the analyses showed a positive correlation between them. Finally, we successfully constructed hub gene-associated TF-gene and ceRNA networks and predicted 11 drugs associated with hub genes. GSEA suggests that hub genes are related to multiple immune response processes.

Conclusion

FBXO7, RAD23A, and MKRN1 are significantly associated with CD8+ T cells in CAD and multiple cancers and may act through immune responses in CAD and cancer.

Cardiovascular health and healthy longevity in people with and without cardiometabolic disease: A prospective cohort study

BACKGROUND

Existing evidence suggest an association of cardiovascular health (CVH) level with cardiometabolic disease (CMD) and mortality, but the effect of CVH on life expectancy, particularly survival years in CMD patients, has not been well-established. This study aimed to investigate the association of CVH defined using the 7-item tool from the American Heart Association (AHA) with life expectancy in people with and without CMD.

METHODS

Between 2006 and 2010, a total of 341,331 participants (age 37-73 years) in the UK Biobank were examined and thereafter followed up to 2020. The CVH raised by the AHA included 4 behavioral (smoking, diet, physical activity, body mass index) and 3 biological (fasting glucose, blood cholesterol, blood pressure) metrics, coded on a three-point scale (0, 1, 2). The CVH score was the sum of 7 metrics (score range 0-14) and was then categorized into poor (scores 0-6), intermediate (7-11), and ideal (12-14) CVH. The flexible parametric survival models were applied to estimate life expectancy.

FINDINGS

During a median follow-up of 11.4 years, 18,420 (5.4%) deaths occurred. The multivariable-adjusted hazard ratio (HRs) of all-cause mortality were 2.21 (95% CI: 1.77 to 2.75) for male and 2.63 (95% CI: 2.22 to 3.12) for female with prevalent CMD and a poor CVH compared with CMD-free and ideal CVH group, an ideal CVH attenuated the CMD-related risk of mortality by approximately 62% for male and 53% for female. In CMD patients, an ideal CVH compared to poor CVH was associated with additional life years gain of 5.50 (95% CI: 3.94-7.05) for male 4.20 (95% CI: 2.77-5.62) for female at the age of 45 years. Corresponding estimates in those without CMD were 4.55 (95% CI: 3.62-5.48) and 4.89 (95% CI: 3.99-5.79), respectively. Ideal smoking status, fasting glucose and physical activity for male and ideal smoking status, cholesterol level and physical activity for female contributed to the greatest survival benefit.

INTERPRETATION

An ideal CVH is associated with a lower risk of premature mortality and longer life expectancy whether in general population or CMD patients. Our study highlights the benefits of maintaining better CVH across the life course and calls attention to the need for comprehensive strategies (healthy behavioral lifestyle and biological phenotypes) to preserve and restore a higher CVH level.

FUNDING

Scientific Research Foundation for Scholars of HZNU (Grant No. 4265C50221204119).

Longevity Factor FOXO3: A Key Regulator in Aging-Related Vascular Diseases

Forkhead box O3 (FOXO3) has been proposed as a homeostasis regulator, capable of integrating multiple upstream signaling pathways that are sensitive to environmental changes and counteracting their adverse effects due to external changes, such as oxidative stress, metabolic stress and growth factor deprivation. FOXO3 polymorphisms are associated with extreme human longevity. Intriguingly, longevity-associated single nucleotide polymorphisms (SNPs) in human FOXO3 correlate with lower-than-average morbidity from cardiovascular diseases in long-lived people. Emerging evidence indicates that FOXO3 plays a critical role in vascular aging. FOXO3 inactivation is implicated in several aging-related vascular diseases. In experimental studies, FOXO3-engineered human ESC-derived vascular cells improve vascular homeostasis and delay vascular aging. The purpose of this review is to explore how FOXO3 regulates vascular aging and its crucial role in aging-related vascular diseases.

Evaluation of the Effect of rs13217795 Genotype and Minor Allele (C) on Clinical Chemistry and Genetic Risk of Diabetes Among the Elderly Individuals from Northern India

The forkhead box O family (FOXO) is expressed ubiquitously in a spatio-temporal manner and plays a key role in cellular metabolism, senescence, and aging. Genetic mutations in FOXO lead to metabolic diseases and cancer,and affect the longevity of individuals. Our study investigated how the genetic risk of type 2 diabetes mellitus (T2DM) altered due to an intronic variant rs13217795 of the longevity-associated <i>FOXO3</i> gene in the geriatric population of North India. Genotypic characteristics of rs13217795 were determined among 347 age sex-matched (177 diabetic cases, 170 healthy controls) elderly individuals by TaqMan SNP assays after clinical assessment. Clinical chemistry and circulating cytokines level were assessed by biochemical and immunoassays. Genotype frequencies were not significantly (<i>p</i> = 0.526) different between cases and controls. The minor allele (C) frequency in diabetic cases and controls was 0.47 and 0.49, respectively (OR = 0.94, 95% CI = 0.69–1.26, <i>p</i> &#x3e; 0.05). The minor allele was associated with lower fasting plasma glucose (FPG), fasting insulin, HOMA-IR, CRP, TNF-α, and IL-6 (<i>p</i> &#x3c; 0.05). The homozygous minor allele carriers showed significantly lower levels of FPG, HOMA-IR, and TNF-α in T2DM patients. The minor allele (C) of intronic polymorphism in <i>FOXO3</i> (rs13217795: T/C) confers the protective role characterized by its association with a decrease in glycemic and insulin resistance and proinflammatory markers.

A description of the relationship in healthy longevity and aging-related disease: from gene to protein

Human longevity is a complex phenotype influenced by both genetic and environmental factors. It is also known to be associated with various types of age-related diseases, such as Alzheimer's disease (AD) and cardiovascular disease (CVD). The central dogma of molecular biology demonstrates the conversion of DNA to RNA to the encoded protein. These proteins interact to form complex cell signaling pathways, which perform various biological functions. With prolonged exposure to the environment, the in vivo homeostasis adapts to the changes, and finally, humans adopt the phenotype of longevity or aging-related diseases. In this review, we focus on two different states: longevity and aging-related diseases, including CVD and AD, to discuss the relationship between genetic characteristics, including gene variation, the level of gene expression, regulation of gene expression, the level of protein expression, both genetic and environmental influences and homeostasis based on these phenotypes shown in organisms.

The correlation of salivary telomere length and single nucleotide polymorphisms of the ADIPOQ, SIRT1 and FOXO3A genes with lifestyle-related diseases in a Japanese population

Background

It has been reported that genetic factors are associated with risk factors and onset of lifestyle-related diseases, but this finding is still the subject of much debate.

Objective

The aim of the present study was to investigate the correlation of genetic factors, including salivary telomere length and three single nucleotide polymorphisms (SNPs) that may influence lifestyle-related diseases, with lifestyle-related diseases themselves.

Methods

In one year at a single facility, relative telomere length and SNPs were determined by using monochrome multiplex quantitative polymerase chain reaction and TaqMan SNP Genotyping Assays, respectively, and were compared with lifestyle-related diseases in 120 Japanese individuals near our university.

Results

In men and all participants, age was inversely correlated with relative telomere length with respective p values of 0.049 and 0.034. In men, the frequency of hypertension was significantly higher in the short relative telomere length group than in the long group with unadjusted p value of 0.039, and the difference in the frequency of hypertension between the two groups was of borderline statistical significance after adjustment for age (p = 0.057). Furthermore, in men and all participants, the sum of the number of affected lifestyle-related diseases, including hypertension, was significantly higher in the short relative telomere length group than in the long group, with p values of 0.004 and 0.029, respectively. For ADIPOQ rs1501299, men’s ankle brachial index was higher in the T/T genotype than in the G/G and G/T genotypes, with p values of 0.001 and 0.000, respectively. For SIRT1 rs7895833, men’s body mass index and waist circumference and all participants’ brachial-ankle pulse wave velocity were higher in the A/G genotype than in the G/G genotype, with respective p values of 0.048, 0.032 and 0.035. For FOXO3A rs2802292, women’s body temperature and all participants’ saturation of peripheral oxygen were lower in the G/T genotype than in the T/T genotype, with respective p values of 0.039 and 0.032. However, relative telomere length was not associated with physiological or anthropometric measurements except for height in men (p = 0.016). ADIPOQ rs1501299 in men, but not the other two SNPs, was significantly associated with the sum of the number of affected lifestyle-related diseases (p = 0.013), by genotype. For each SNPs, there was no significant difference in the frequency of hypertension or relative telomere length by genotype.

Conclusion

Relative telomere length and the three types of SNPs determined using saliva have been shown to be differentially associated with onset of and measured risk factors for lifestyle-related diseases consisting mainly of cardiovascular diseases and cancer.

FOXO3 longevity genotype mitigates the increased mortality risk in men with a cardiometabolic disease

FOXO3 is a prominent longevity gene. To date, no-one has examined whether longevity-associated FOXO3 genetic variants protect against mortality in all individuals, or only in those with aging-related diseases. We therefore tested longevity-associated FOXO3 single nucleotide polymorphisms in a haplotype block for association with mortality in 3,584 elderly American men of Japanese ancestry, 2,512 with and 1,072 without a cardiometabolic disease (CMD). At baseline (1991–1993), 1,010 CMD subjects had diabetes, 1,919 had hypertension, and 738 had coronary heart disease (CHD). Follow-up until Dec 31, 2019 found that in CMD-affected individuals, longevity-associated alleles of FOXO3 were associated with significantly longer lifespan: haplotype hazard ratio 0.81 (95% CI 0.72-0.91; diabetes 0.77, hypertension 0.82, CHD 0.83). Overall, men with a CMD had higher mortality than men without a CMD (P=6x10^-7). However, those men with a CMD who had the FOXO3 longevity genotype had similar survival as men without a CMD. In men without a CMD there was no association of longevity-associated alleles of FOXO3 with lifespan. Our study provides novel insights into the basis for the long-established role of FOXO3 as a longevity gene. We suggest that the FOXO3 longevity genotype increases lifespan only in at-risk individuals by protection against cardiometabolic stress.

Genetic variants of VEGFR-1 gene promoter in acute myocardial infarction

BACKGROUND

Coronary artery disease (CAD) including acute myocardial infarction (AMI) is a common complex disease caused by atherosclerosis. Vascular epithelial growth factor receptor-1 (VEGFR-1) stimulates angiogenesis and vascular permeability, and functions as a decoy to sequester VEGF and prevent initiation of intracellular signaling. VEGFR-1 knockout mice exhibit significantly higher mortality due to heart failure, cardiac hypertrophy, and cardiac dysfunction. An evident increase in macrophage infiltration and cardiac fibrosis are also observed after transverse aortic constriction. Therefore, VEGFR-1 gene variants may be involved in CAD. In this study, VEGFR-1 gene promoter was genetically and functionally analyzed in large cohorts of AMI patients and ethnic-matched controls.

RESULTS

A total of 16 DNA sequence variants (DSVs) including six single-nucleotide polymorphisms (SNPs) were found in the VEGFR-1 gene promoter and 5'-untranslated region. Five novel DSVs and one SNP were only identified in AMI patients group. These DSVs and SNP significantly altered the transcriptional activity of the VEGFR-1 gene promoter in both HEK-293 and H9c2 cells (P < 0.05). Further electrophoretic mobility shift assay indicated that the DSVs and SNPs evidently affected the binding of transcription factors.

CONCLUSIONS

The genetic variants in VEGFR-1 gene identified in AMI patients may alter the transcriptional activity of the VEGFR-1 gene promoter and change VEGFR-1 level, contributing to AMI development.

Genetic Variation in FOXO3 is Associated with Self-Rated Health in a Population-Based Sample of Older Individuals

Self-rated health (SRH) strongly predicts mortality. Twin studies estimate that genetic factors account for a substantial part of the variability in SRH. Variations in the gene FOXO3 (forkhead box O3), and in genes located at the APOE (apoplipoprotein E) locus, are associated with longevity. This study explores the relationship between SRH and genetic variation related to longevity, in a population-based cohort of older individuals. SRH was assessed among 1,520 individuals aged 75–87, and five single nucleotide polymorphisms (SNPs), in APOE, TOMM40 (translocase of outer mitochondrial membrane 40 homolog), and FOXO3 were genotyped. Two SNPs (rs10457180 and rs2802292) in FOXO3 were associated with SRH (OR = 2.18 [CI: 1.27–3.76], p = .005 and OR = 1.63 [CI: 1.11–2.40], p = .013), while no associations were found with SNPs in APOE and TOMM40. Several factors, such as depression, cardiovascular disease (CVD), and diabetes, were related to SRH, but the only factor that had any influence on the association with FOXO3 was CVD. Still, after including CVD as a covariate, the associations between FOXO3 SNPs and SRH remained significant. Our results suggest that FOXO3 is related to SRH in older individuals. This relationship seems to be influenced by CVD, but not by mental and cognitive status.

The longevity SNP rs2802292 uncovered: HSF1 activates stress-dependent expression of FOXO3 through an intronic enhancer

The HSF and FOXO families of transcription factors play evolutionarily conserved roles in stress resistance and lifespan. In humans, the rs2802292 G-allele at FOXO3 locus has been associated with longevity in all human populations tested; moreover, its copy number correlated with reduced frequency of age-related diseases in centenarians. At the molecular level, the intronic rs2802292 G-allele correlated with increased expression of FOXO3, suggesting that FOXO3 intron 2 may represent a regulatory region. Here we show that the 90-bp sequence around the intronic single nucleotide polymorphism rs2802292 has enhancer functions, and that the rs2802292 G-allele creates a novel HSE binding site for HSF1, which induces FOXO3 expression in response to diverse stress stimuli. At the molecular level, HSF1 mediates the occurrence of a promoter–enhancer interaction at FOXO3 locus involving the 5′UTR and the rs2802292 region. These data were confirmed in various cellular models including human HAP1 isogenic cell lines (G/T). Our functional studies highlighted the importance of the HSF1-FOXO3-SOD2/CAT/GADD45A cascade in cellular stress response and survival by promoting ROS detoxification, redox balance and DNA repair. Our findings suggest the existence of an HSF1-FOXO3 axis in human cells that could be involved in stress response pathways functionally regulating lifespan and disease susceptibility.

Genetic and epigenetic regulation of human aging and longevity

Here we summarize the latest data on genetic and epigenetic contributions to human aging and longevity. Whereas environmental and lifestyle factors are important at younger ages, the contribution of genetics appears more important in reaching extreme old age. Genome-wide studies have implicated ~57 gene loci in lifespan. Epigenomic changes during aging profoundly affect cellular function and stress resistance. Dysregulation of transcriptional and chromatin networks is likely a crucial component of aging. Large-scale bioinformatic analyses have revealed involvement of numerous interaction networks. As the young well-differentiated cell replicates into eventual senescence there is drift in the highly regulated chromatin marks towards an entropic middle-ground between repressed and active, such that genes that were previously inactive "leak". There is a breakdown in chromatin connectivity such that topologically associated domains and their insulators weaken, and well-defined blocks of constitutive heterochromatin give way to generalized, senescence-associated heterochromatin, foci. Together, these phenomena contribute to aging.

FOXO3 on the Road to Longevity: Lessons From SNPs and Chromatin Hubs

Health span is driven by a precise interplay between genes and the environment. Cell response to environmental cues is mediated by signaling cascades and genetic variants that affect gene expression by regulating chromatin plasticity. Indeed, they can promote the interaction of promoters with regulatory elements by forming active chromatin hubs.

FOXO3 encodes a transcription factor with a strong impact on aging and age-related phenotypes, as it regulates stress response, therefore affecting lifespan. A significant association has been shown between human longevity and several FOXO3 variants located in intron 2. This haplotype block forms a putative aging chromatin hub in which FOXO3 has a central role, as it modulates the physical connection and activity of neighboring genes involved in age-related processes.

Here we describe the role of FOXO3 and its single-nucleotide polymorphisms (SNPs) in healthy aging, with a focus on the enhancer region encompassing the SNP rs2802292, which upregulates FOXO3 expression and can promote the activity of the aging hub in response to different stress stimuli. FOXO3 protective effect on lifespan may be due to the accessibility of this region to transcription factors promoting its expression. This could in part explain the differences in FOXO3 association with longevity between genders, as its activity in females may be modulated by estrogens through estrogen receptor response elements located in the rs2802292-encompassing region. Altogether, the molecular mechanisms described here may help establish whether the rs2802292 SNP can be taken advantage of in predictive medicine and define the potential of targeting FOXO3 for age-related diseases.

Chasing the FOXO3: Insights into Its New Mitochondrial Lair in Colorectal Cancer Landscape

Colorectal cancer (CRC) poses a formidable challenge in terms of molecular heterogeneity, as it involves a variety of cancer-related pathways and molecular changes unique to an individual’s tumor. On the other hand, recent advances in DNA sequencing technologies provide an unprecedented capacity to comprehensively identify the genetic alterations resulting in tumorigenesis, raising the hope that new therapeutic approaches based on molecularly targeted drugs may prevent the occurrence of chemoresistance. Regulation of the transcription factor FOXO3a in response to extracellular cues plays a fundamental role in cellular homeostasis, being part of the molecular machinery that drives cells towards survival or death. Indeed, FOXO3a is controlled by a range of external stimuli, which not only influence its transcriptional activity, but also affect its subcellular localization. These regulation mechanisms are mediated by cancer-related signaling pathways that eventually drive changes in FOXO3a post-translational modifications (e.g., phosphorylation). Recent results showed that FOXO3a is imported into the mitochondria in tumor cells and tissues subjected to metabolic stress and cancer therapeutics, where it induces expression of the mitochondrial genome to support mitochondrial metabolism and cell survival. The current review discusses the potential clinical relevance of multidrug therapies that drive cancer cell fate by regulating critical pathways converging on FOXO3a.

Exceptional Longevity and Polygenic Risk for Cardiovascular Health

Studies investigating exceptionally long-lived (ELL) individuals, including genetic studies, have linked cardiovascular-related pathways, particularly lipid and cholesterol homeostasis, with longevity. This study explored the genetic profiles of ELL individuals (cases: n = 294, 95–106 years; controls: n = 1105, 55–65 years) by assessing their polygenic risk scores (PRS) based on a genome wide association study (GWAS) threshold of p < 5 × 10⁻⁵. PRS were constructed using GWAS summary data from two exceptional longevity (EL) analyses and eight cardiovascular-related risk factors (lipids) and disease (myocardial infarction, coronary artery disease, stroke) analyses. A higher genetic risk for exceptional longevity (EL) was significantly associated with longevity in our sample (odds ratio (OR) = 1.19–1.20, p = 0.00804 and 0.00758, respectively). Two cardiovascular health PRS were nominally significant with longevity (HDL cholesterol, triglycerides), with higher PRS associated with EL, but these relationships did not survive correction for multiple testing. In conclusion, ELL individuals did not have significantly lower polygenic risk for the majority of the investigated cardiovascular health traits. Future work in larger cohorts is required to further explore the role of cardiovascular-related genetic variants in EL.

Genetic susceptibility of five tagSNPs in the endothelin-1 (EDN1) gene to coronary artery disease in a Chinese Han population

Endothelin-1 (ET-1) plays important roles in endothelial dysfunction, vascular physiology, inflammation, and atherosclerosis. Nonetheless, the role of ET-1 (EDN1) gene variants on coronary artery disease (CAD) risk remains poorly understood. The aim of the present study was to evaluate the role of EDN1 gene polymorphisms on individual susceptibility to CAD. We genotyped five tagSNPs (single-nucleotide polymorphisms) (rs6458155, rs4145451, rs9369217, rs3087459, and rs2070699) within EDN1 gene in 525 CAD patients and 675 control subjects. In a multivariate logistic regression analysis, we detected an association of rs6458155 in EDN1 gene with the CAD risk; compared with the TT homozygotes, the CT heterozygotes (odds ratio (OR) = 1.53, 95% confidence interval (CI) = 1.02–2.29, P=0.040) and the CC homozygotes (OR = 1.55, 95% CI = 1.01–2.36, P=0.043) were statistically significantly associated with the increased risk for CAD. A similar trend of the association was found in dominant model (OR = 1.53, 95% CI = 1.05–2.25, P=0.029). Consistently, the haplotype rs6458155C-rs4145451C containing rs6458155 C allele exhibited the increased CAD risk (OR = 1.22, 95% CI = 1.03–1.43, and P=0.018). In addition, CT genotype of rs6458155 conferred the increased plasma ET-1 levels compared with TT genotype (P<0.05). No association of the other four tagSNPs in EDN1 gene with CAD risk was observed. In conclusion, our study provides the first evidence that EDN1 tagSNP rs6458155 is associated with CAD risk in the Chinese Han population, which is probably due to the influence of the circulating ET-1 levels.

Limitations and risks of meta-analyses of longevity studies

Searching for genetic determinants of human longevity has been challenged by the rarity of data sets with large numbers of individuals who have reached extreme old age, inconsistent definitions of the phenotype, and the difficulty of defining appropriate controls. Meta-analysis - a statistical method to summarize results from different studies - has become a common tool in genetic epidemiology to accrue large sample sizes for powerful genetic association studies. In conducting a meta-analysis of studies of human longevity however, particular attention must be made to the definition of cases and controls (including their health status) and on the effect of possible confounders such as sex and ethnicity upon the genetic effect to be estimated. We will show examples of how a meta-analysis can inflate the false negative rates of genetic association studies or it can bias estimates of the association between a genetic variant and extreme longevity.

Genetic Association Analysis of Common Variants in FOXO3 Related to Longevity in a Chinese Population

Recent studies suggested that forkhead box class O3 (FOXO3) functions as a key regulator for the insulin/insulin-like growth factor-1signaling pathway that influence aging and longevity. This study aimed to comprehensively elucidate the association of common genetic variants in FOXO3 with human longevity in a Chinese population. Eighteen single-nucleotide polymorphisms (SNPs) in FOXO3 were successfully genotyped in 616 unrelated long-lived individuals and 846 younger controls. No nominally significant effects were found. However, when stratifying by gender, four SNPs (rs10499051, rs7762395, rs4946933 and rs3800230) previously reported to be associated with longevity and one novel SNP (rs4945815) showed significant association with male longevity (P-values: 0.007–0.032), but all SNPs were not associated with female longevity. Correspondingly, males carrying the G-G-T-G haplotype of rs10499051, rs7762395, rs4945815 and rs3800230 tended to have longer lifespan than those carrying the most common haplotype A-G-C-T (odds ratio = 2.36, 95% confidence interval = 1.20–4.63, P = 0.013). However, none of the associated SNPs and haplotype remained significant after Bonferroni correction. In conclusion, our findings revealed that the FOXO3 variants we tested in our population of Chinese men and women were associated with longevity in men only. None of these associations passed Bonferroni correction. Bonferroni correction is very stringent for association studies. We therefore believe the effects of these nominally significant variants on human longevity will be confirmed by future studies.