Effects of FOXO3 Polymorphisms on Survival to Extreme Longevity in Four Centenarian Studies

Multimodal Omics Approaches to Aging and Age-Related Diseases

Aging is associated with a progressive decline in physiological capacities and an increased risk of aging-associated disorders. An increasing body of experimental evidence shows that aging is a complex biological process coordinately regulated by multiple factors at different molecular layers. Thus, it is difficult to delineate the overall systematic aging changes based on single-layer data. Instead, multimodal omics approaches, in which data are acquired and analyzed using complementary omics technologies, such as genomics, transcriptomics, and epigenomics, are needed for gaining insights into the precise molecular regulatory mechanisms that trigger aging. In recent years, multimodal omics sequencing technologies that can reveal complex regulatory networks and specific phenotypic changes have been developed and widely applied to decode aging and age-related diseases. This review summarizes the classification and progress of multimodal omics approaches, as well as the rapidly growing number of articles reporting on their application in the field of aging research, and outlines new developments in the clinical treatment of age-related diseases based on omics technologies.

Discovering Biological Mechanisms of Exceptional Human Health Span and Life Span

Humans age at different rates and families with exceptional longevity provide an opportunity to understand why some people age slower than others. Unique features exhibited by centenarians include a family history of extended life span, compression of morbidity with resultant extension of health span, and longevity-associated biomarker profiles. These biomarkers, including low-circulating insulin-like growth factor 1 (IGF-1) and elevated high-density lipoprotein (HDL) cholesterol levels, are associated with functional genotypes that are enriched in centenarians, suggesting that they may be causative for longevity. While not all genetic discoveries from centenarians have been validated, in part due to exceptional life span being a rare phenotype in the general population, the APOE2 and FOXO3a genotypes have been confirmed in a number of populations with exceptional longevity. However, life span is now recognized as a complex trait and genetic research methods to study longevity are rapidly extending beyond classical Mendelian genetics to polygenic inheritance methodologies. Moreover, newer approaches are suggesting that pathways that have been recognized for decades to control life span in animals may also regulate life span in humans. These discoveries led to strategic development of therapeutics that may delay aging and prolong health span.

Chromatin remodeler Activity-Dependent Neuroprotective Protein (ADNP) contributes to syndromic autism

BACKGROUND

Individuals affected with autism often suffer additional co-morbidities such as intellectual disability. The genes contributing to autism cluster on a relatively limited number of cellular pathways, including chromatin remodeling. However, limited information is available on how mutations in single genes can result in such pleiotropic clinical features in affected individuals. In this review, we summarize available information on one of the most frequently mutated genes in syndromic autism the Activity-Dependent Neuroprotective Protein (ADNP).

RESULTS

Heterozygous and predicted loss-of-function ADNP mutations in individuals inevitably result in the clinical presentation with the Helsmoortel-Van der Aa syndrome, a frequent form of syndromic autism. ADNP, a zinc finger DNA-binding protein has a role in chromatin remodeling: The protein is associated with the pericentromeric protein HP1, the SWI/SNF core complex protein BRG1, and other members of this chromatin remodeling complex and, in murine stem cells, with the chromodomain helicase CHD4 in a ChAHP complex. ADNP has recently been shown to possess R-loop processing activity. In addition, many additional functions, for instance, in association with cytoskeletal proteins have been linked to ADNP.

CONCLUSIONS

We here present an integrated evaluation of all current aspects of gene function and evaluate how abnormalities in chromatin remodeling might relate to the pleiotropic clinical presentation in individual"s" with Helsmoortel-Van der Aa syndrome.

Aging Hallmarks and the Role of Oxidative Stress

Aging is a complex biological process accompanied by a progressive decline in the physical function of the organism and an increased risk of age-related chronic diseases such as cardiovascular diseases, cancer, and neurodegenerative diseases. Studies have established that there exist nine hallmarks of the aging process, including (i) telomere shortening, (ii) genomic instability, (iii) epigenetic modifications, (iv) mitochondrial dysfunction, (v) loss of proteostasis, (vi) dysregulated nutrient sensing, (vii) stem cell exhaustion, (viii) cellular senescence, and (ix) altered cellular communication. All these alterations have been linked to sustained systemic inflammation, and these mechanisms contribute to the aging process in timing not clearly determined yet. Nevertheless, mitochondrial dysfunction is one of the most important mechanisms contributing to the aging process. Mitochondria is the primary endogenous source of reactive oxygen species (ROS). During the aging process, there is a decline in ATP production and elevated ROS production together with a decline in the antioxidant defense. Elevated ROS levels can cause oxidative stress and severe damage to the cell, organelle membranes, DNA, lipids, and proteins. This damage contributes to the aging phenotype. In this review, we summarize recent advances in the mechanisms of aging with an emphasis on mitochondrial dysfunction and ROS production.

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.

Association study to evaluate Foxo1 and Foxo3 gene polymorphisms in polycystic ovary syndrome: a preliminary case-control study and in silico analysis

BACKGROUND

Polycystic ovary syndrome (PCOS) is known as a multifactorial and multi-gene-mediated endocrine disorder among women of reproductive age. FoxO1 and FoxO3 are members of the forkhead transcriptional factors family that play a pivotal role in the function of ovaries. The current work is aimed at investigating the association between gene variants of FoxO1 and FoxO3 and the risk of PCOS in a sample of the Iranian population.

METHODS AND RESULTS

We recruited 200 women diagnosed with PCOS and 200 healthy women. Both polymerase PCR-RFLP and ARMS-PCR methods were used for genotyping. Sanger sequencing was recruited to confirm the genotyping results. The T allele of rs17592236 and the C allele of rs12585277 decreased PCOS risk by 29 and 28%, respectively. In contrast, the C allele of rs2253310 and G allele of rs2802292 increased the risk of PCOS by 1.39 and 1.63 folds, correspondingly. Bioinformatics results showed that some genes, including matrix metallopeptidase 9 (MMP-9), phosphoinositide-3-Kinase Regulatory Subunit 224 1 (PIK3R1), peroxisome proliferator-activated receptor Gamma (PPARG), and glycogen synthase 225 kinase-3 beta (GSK-3 beta) have significant interactions with FoxO1, suggesting that FoxO1 might have crucial roles in regulating different signaling pathways in ovarian cells.

CONCLUSION

We found that FoxO1 rs17592236C > T and rs12585277C > T had a protective role against PCOS, while FoxO3 rs2253310C > G and rs2802292G > T  enhanced the risk of this metabolic disorder in our population. Additional studies on larger populations with varying races are needed to confirm these findings.

A Genome-Wide Association Study of 2304 Extreme Longevity Cases Identifies Novel Longevity Variants

We performed a genome-wide association study (GWAS) of human extreme longevity (EL), defined as surviving past the 99th survival percentile, by aggregating data from four centenarian studies. The combined data included 2304 EL cases and 5879 controls. The analysis identified a locus in CDKN2B-AS1 (rs6475609, p = 7.13 × 10-8) that almost reached genome-wide significance and four additional loci that were suggestively significant. Among these, a novel rare variant (rs145265196) on chromosome 11 had much higher longevity allele frequencies in cases of Ashkenazi Jewish and Southern Italian ancestry compared to cases of other European ancestries. We also correlated EL-associated SNPs with serum proteins to link our findings to potential biological mechanisms that may be related to EL and are under genetic regulation. The findings from the proteomic analyses suggested that longevity-promoting alleles of significant genetic variants either provided EL cases with more youthful molecular profiles compared to controls or provided some form of protection from other illnesses, such as Alzheimer's disease, and disease progressions.

Optimizing Translational Research for Exceptional Health and Life Span: A Systematic Narrative of Studies to Identify Translatable Therapeutic Target(s) for Exceptional Health Span in Humans

BACKGROUND

Exceptional longevity as manifested by the lower incidence and delayed onset of age-related disabilities/diseases that include cardiovascular disease, Alzheimer's disease, cancer is believed to be influenced by inherent protective molecular factors in exceptionally long-lived individuals. Unraveling these protective factors could lead to the discovery of therapeutic target(s) and interventions to promote healthy aging.

METHODS

In this context, the National Institute on Aging has established a collection of translational longevity research projects (ie, the Long-Life Family Study, the Longevity Consortium, Longevity Genomics, and the Integrative Longevity Omics) which are generating large omics data sets spanning the human genome to phenome and have embarked on cross-species multiomic data analyses integrating human and nonhuman species that display wide variation in their life spans.

RESULTS

It is expected that these studies will discover key signaling pathways that influence exceptional health span and identify therapeutic targets for translation to enhance health and life span. Other efforts related to translational longevity research include the "Comprehensive Evaluation of Aging-Related Clinical Outcomes and Geroproteins study," which focuses on potential effects in humans of polypeptides/proteins whose circulating levels change with age, and for which experimental evidence indicates reversal or acceleration of aging changes. The "Predictive Human Mechanistic Markers Network" is devoted to the development of predictive markers of aging, for target engagement when testing novel interventions for healthy aging.

CONCLUSION

We describe here the significance, the unique study design, categories of data sets, analytical strategies, and a data portal to facilitate open science and sharing of resources from these longevity studies to identify and validate potential therapeutic targets for healthy aging.

Oxidative stress, aging, antioxidant supplementation and their impact on human health: An overview

Aging is characterized by a progressive loss of tissue and organ function due to genetic and environmental factors, nutrition, and lifestyle. Oxidative stress is one the most important mechanisms of cellular senescence and increased frailty, resulting in several age-linked, noncommunicable diseases. Contributing events include genomic instability, telomere shortening, epigenetic mechanisms, reduced proteome homeostasis, altered stem-cell function, defective intercellular communication, progressive deregulation of nutrient sensing, mitochondrial dysfunction, and metabolic unbalance. These complex events and their interplay can be modulated by dietary habits and the ageing process, acting as potential measures of primary and secondary prevention. Promising nutritional approaches include the Mediterranean diet, the intake of dietary antioxidants, and the restriction of caloric intake. A comprehensive understanding of the ageing processes should promote new biomarkers of risk or diagnosis, but also beneficial treatments oriented to increase lifespan.

Novel ADNP Syndrome Mice Reveal Dramatic Sex-Specific Peripheral Gene Expression With Brain Synaptic and Tau Pathologies

BACKGROUND

ADNP is essential for embryonic development. As such, de novo ADNP mutations lead to an intractable autism/intellectual disability syndrome requiring investigation.

METHODS

Mimicking humans, CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 editing produced mice carrying heterozygous Adnp p.Tyr718∗ (Tyr), a paralog of the most common ADNP syndrome mutation. Phenotypic rescue was validated by treatment with the microtubule/autophagy-protective ADNP fragment NAPVSIPQ (NAP).

RESULTS

RNA sequencing of spleens, representing a peripheral biomarker source, revealed Tyr-specific sex differences (e.g., cell cycle), accentuated in females (with significant effects on antigen processing and cellular senescence) and corrected by NAP. Differentially expressed, NAP-correctable transcripts, including the autophagy and microbiome resilience-linked FOXO3, were also deregulated in human patient-derived ADNP-mutated lymphoblastoid cells. There were also Tyr sex-specific microbiota signatures. Phenotypically, Tyr mice, similar to patients with ADNP syndrome, exhibited delayed development coupled with sex-dependent gait defects. Speech acquisition delays paralleled sex-specific mouse syntax abnormalities. Anatomically, dendritic spine densities/morphologies were decreased with NAP amelioration. These findings were replicated in the Adnp^+/- mouse, including Foxo3 deregulation, required for dendritic spine formation. Grooming duration and nociception threshold (autistic traits) were significantly affected only in males. Early-onset tauopathy was accentuated in males (hippocampus and visual cortex), mimicking humans, and was paralleled by impaired visual evoked potentials and correction by acute NAP treatment.

CONCLUSIONS

Tyr mice model ADNP syndrome pathology. The newly discovered ADNP/NAP target FOXO3 controls the autophagy initiator LC3 (microtubule-associated protein 1 light chain 3), with known ADNP binding to LC3 augmented by NAP, protecting against tauopathy. NAP amelioration attests to specificity, with potential for drug development targeting accessible biomarkers.

Protective Effects of Familial Longevity Decrease With Age and Become Negligible for Centenarians

It is known that biological relatives of long-lived individuals demonstrate lower mortality and longer life span compared to relatives of shorter-lived individuals, and at least part of this advantage is likely to be genetic. Less information, however, is available about effects of familial longevity on age-specific mortality trajectories. We compared mortality patterns after age 50 years for 10 045 siblings of US centenarians and 12 308 siblings of shorter-lived individuals (died at age 65 years). Similar comparisons were made for sons and daughters of longer-lived parents (both parents lived 80 years and more) and shorter-lived parents (both parents lived less than 80 years) within each group of siblings. Although relatives of longer-lived individuals have lower mortality at younger ages compared to relatives of shorter-lived individuals, this mortality advantage practically disappears by age 100 years. To validate this observation further, we analyzed the survival of 3 408 US centenarians born in 1890-1897 with known information on maternal and paternal life span. We found using the Cox proportional hazards model that both maternal and paternal longevity (life span 80+ years) is not significantly associated with survival after age 100 years. The results are compatible with the predictions of reliability theory of aging suggesting higher initial levels of system redundancy (reserves) in individuals with protective familial/genetic background and hence lower initial mortality. Heterogeneity hypothesis is another possible explanation for the observed phenomena.

The 90 plus: longevity and COVID-19 survival

The world population is getting older and studies aiming to enhance our comprehension of the underlying mechanisms responsible for health span are of utmost interest for longevity and as a measure for health care. In this review, we summarized previous genetic association studies (GWAS) and next-generation sequencing (NGS) of elderly cohorts. We also present the updated hypothesis for the aging process, together with the factors associated with healthy aging. We discuss the relevance of studying older individuals and build databanks to characterize the presence and resistance against late-onset disorders. The identification of about 2 million novel variants in our cohort of more than 1000 elderly Brazilians illustrates the importance of studying highly admixed populations of non-European ancestry. Finally, the ascertainment of nonagenarians and particularly of centenarians who were recovered from COVID-19 or remained asymptomatic opens new avenues of research aiming to enhance our comprehension of biological mechanisms associated with resistance against pathogens.

New Directions in Research on Aging

Biology of aging is an active and rapidly expanding area of biomedical research. Over the years, focus of work in this field has been gradually shifting from studying the effects and symptoms of aging to searching for mechanisms of the aging process. Progress of this work led to an additional shift from looking for "the mechanism" of aging and formulating the corresponding "theories of aging" to appreciation that aging represents a net result of multiple physiological changes and their intricate interactions. It was also shown that mechanisms of aging include nutrient-dependent signaling pathways which have been remarkably conserved in the course of the evolution. Another important development in this field is increased emphasis on searching for pharmacological and environmental interventions that can extend healthspan or influence other aspects of aging. Progress in understanding the key role of aging as a risk factor for chronic disease provides impetus for these studies. Data from the recent pandemic provided additional evidence for the impact of age on resilience. Progress of work in this area also was influenced by major analytical and technological advances, including greatly improved methods for the study of gene expression, protein, lipids, and metabolites profiles, enhanced ability to produce various genetic modifications and novel approaches to assessment of biological age. Progress in research on the biology of aging provides reasons for optimism about the chances that safe and widely applicable anti-aging interventions with significant benefits for both individual and public health will be developed in the not too distant future.

Genetic, environmental and life-style factors associated with longevity. Protocol and response of the LONGECYL Study

OBJECTIVE

To describe the objectives, the methodological approach, the response rate of the Genetic, Environmental and Life-style Factors Study in Castilla y León (Spain).

METHOD

The Health Sentinel Network studied a sample of long-lived individuals aged 95 or more (LLI). The study included biological samples processed with the Global Screening Array v3.0 that contains a total of 730,059 markers. Written consent was obtained before the examination.

CONCLUSIONS

The LLI contacted were 944, and 760 were completed studied. The 87.4% of LLI were born in Castile and Leon and only 1% were non-native of Spain. Severe cognitive impairment was declared in 8.1% of men and 19.2% of women. Genotyping was performed in 739 LLI, the 78.3% of the contacted sample. Family doctors and nurses achieve high participation in population-based studies. DNA samples were taken from 94% of fully studied LLI, and 100% of these samples where successfully genotyped.

Association of FOXO3a gene polymorphisms and ankylosing spondylitis susceptibility in Eastern Chinese Han population

OBJECTIVE

To investigate the association of FOXO3a polymorphisms and ankylosing spondylitis (AS) susceptibility in Eastern Chinese Han population.

METHODS

FOXO3a polymorphisms rs12206094, rs12212067, rs2253310, rs3800232, and rs4946933 were genotyped in 650 AS patients and 646 controls by the improved Multiple Ligase Detection Reaction.

RESULTS

The distribution of genotype in rs12212067 polymorphism was significantly different between AS patients and controls (P = 0.020), especially in male population (P = 0.009). There was significant difference of the genotype frequency distribution at rs3800232 between patients and controls in male population. The results of binary regression analysis showed that the rs12212067 GG genotype and rs3800232 TT genotype were obviously correlated with elevated AS risk, and the associations were still significant after being adjusted by age and gender (all P < 0.05). Interestingly, rs12212067 and rs3800232 genotypes were associated with disease activity of patients. Additionally, haplotype block rs12212067^G- rs3800232^T (OR = 1.403, 95%CI = 1.011-1.949) was further shown to confer promoting effect on developing AS.

CONCLUSION

Among Eastern Chinese Han population, FOXO3a polymorphism rs12212067 and rs3800232 may contribute to increased risk of developing AS, but well-designed multicenter studies are needed to further confirm these preliminary findings in the future.

Nature Versus Nurture: What Can be Learned from the Oldest-Old's Claims About Longevity?

Beneficial genetic or environmental factors that influence the length and quality of life can be evaluated while studying supercentenarians. The oldest-old can withstand serious/fatal illnesses more than their peers and/or their aging rate is decreased. Supercentenarians are an interesting group of individuals whose lifestyle is not particularly healthy according to the common guidelines, namely some of them seem to have similar harmful behaviors, but still manage to stay healthier for longer, and while eventually dying from the same degenerative diseases as the general population, they develop symptoms 20-30 years later. As there are not many supercentenarians by definition, it is worthwhile to diligently collect their data to enable future meta-analyses on larger samples; much can be learned from supercentenarians' habits and lifestyle choices about the aging process. Contributions of genetics, lifestyle choices, and epigenetics to their extended life span are discussed here.

Inflammaging in Endemic Areas for Infectious Diseases

Immunosenescence is marked by a systemic process named inflammaging along with a series of defects in the immunological activity that results in poor responses to infectious agents and to vaccination. Inflammaging, a state of low-grade chronic inflammation, usually leads to chronic inflammatory diseases and frailty in the elderly. However, some elderly escape from frailty and reach advanced age free of the consequences of inflammaging. This process has been called immunological remodeling, and it is the hallmark of healthy aging as described in the studies of centenarians in Italy. The biological markers of healthy aging are still a matter of debate, and the studies on the topic have focused on inflammatory versus remodeling processes and molecules. The sub-clinical inflammatory status associated with aging might be a deleterious event for populations living in countries where chronic infectious diseases are not prevalent. Nevertheless, in other parts of the world where they are, two possibilities may occur. Inflammatory responses may have a protective effect against these infectious agents. At the same time, the long-term consequences of protective immune responses during chronic infections may result in accelerated immunosenescence in these individuals. Therefore, the biological markers of healthy aging can vary according to environmental, cultural, and geographical settings that reflect worldwide, and in a non-biased, non-westernized perspective, the changes that we experience regarding our contacts with microorganisms and the outcomes of such contacts.

Whole-Exome Sequencing of an Exceptional Longevity Cohort

Centenarians represent a unique cohort to study the genetic basis for longevity and factors determining the risk of neurodegenerative disorders, including Alzheimer's disease (AD). The estimated genetic contribution to longevity is highest in centenarians and super-cententenarians, but few genetic variants have been shown to clearly impact this phenotype. While the genetic risk for AD and other dementias is now well understood, the frequency of known dementia risk variants in centenarians is not fully characterized. To address these questions, we performed whole-exome sequencing on 100 individuals of 98-108 years age in search of genes with large effect sizes towards the exceptional aging phenotype. Overall, we were unable to identify a rare protein-altering variant or individual genes with an increased burden of rare variants associated with exceptional longevity. Gene burden analysis revealed three genes of nominal statistical significance associated with extreme aging, including LYST, MDN1, and RBMXL1. Several genes with variants conferring an increased risk for AD and other dementias were identified, including TREM2, EPHA1, ABCA7, PLD3, MAPT, and NOTCH3. Larger centenarian studies will be required to further elucidate the genetic basis for longevity, and factors conferring protection against age-dependent neurodegenerative syndromes.

Genotypic and Phenotypic Aspects of Longevity: Results from a Sicilian Survey and Implication for the Prevention and Treatment of Age-related Diseases

BACKGROUND

It is well known that long living individuals are a model of successful ageing and that the identification of both genetic variants and environmental factors that predispose to a long and healthy life is of tremendous interest for translational medicine.

METHODS

We present the preliminary findings obtained from an ongoing study on longevity conducted on a sample of Sicilian long-lived individuals.

RESULTS

We review the characteristics of longevity in Sicily, taking into account lifestyle, environment, genetics, hematochemical values, body composition and immunophenotype. In addition, we discuss the possible implications of our data for the prevention and/or treatment of age-related diseases.

CONCLUSION

As widely discussed in this review, the explanation of the role of genetics and lifestyle in longevity can provide important information on how to develop drugs and/or behaviours that can slow down or delay ageing. Thus, it will be possible to understand, through a "positive biology" approach, how to prevent and/or reduce elderly frailty and disability.

Redox-mediated regulation of aging and healthspan by an evolutionarily conserved transcription factor HLH-2/Tcf3/E2A

Physiological aging is a complex process, influenced by a plethora of genetic and environmental factors. While being far from fully understood, a number of common aging hallmarks have been elucidated in recent years. Among these, transcriptomic alterations are hypothesized to represent a crucial early manifestation of aging. Accordingly, several transcription factors (TFs) have previously been identified as important modulators of lifespan in evolutionarily distant model organisms. Based on a set of TFs conserved between nematodes, zebrafish, mice, and humans, we here perform a RNA interference (RNAi) screen in C. elegans to discover evolutionarily conserved TFs impacting aging. We identify a basic helix-loop-helix TF, named HLH-2 in nematodes (Tcf3/E2A in mammals), to exert a pronounced lifespan-extending effect in C. elegans upon impairment. We further show that its impairment impacts cellular energy metabolism, increases parameters of healthy aging, and extends nematodal lifespan in a ROS-dependent manner. We then identify arginine kinases, orthologues of mammalian creatine kinases, as a target of HLH-2 transcriptional regulation, serving to mediate the healthspan-promoting effects observed upon impairment of hlh-2 expression. Consistently, HLH-2 is shown to epistatically interact with core components of known lifespan-regulating pathways, i.e. AAK-2/AMPK and LET-363/mTOR, as well as the aging-related TFs SKN-1/Nrf2 and HSF-1. Lastly, single-nucelotide polymorphisms (SNPs) in Tcf3/E2A are associated with exceptional longevity in humans. Together, these findings demonstrate that HLH-2 regulates energy metabolism via arginine kinases and thereby affects the aging phenotype dependent on ROS-signaling and established canonical effectors.

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A C. elegans RNAi screen identifies conserved aging-related transcription factors.

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Impairment of transcription factor hlh-2 has the most pronounced effect on lifespan.

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C. elegans HLH-2 affects cellular energy homeostasis and redox signaling.

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HLH-2 modulates arginine kinase to interact with downstream longevity pathways.

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Polymorphisms (SNPs) in the hlh-2 orthologue Tcf3/E2A are linked to human longevity.

The genetics of human ageing

The past two centuries have witnessed an unprecedented rise in human life expectancy. Sustaining longer lives with reduced periods of disability will require an understanding of the underlying mechanisms of ageing, and genetics is a powerful tool for identifying these mechanisms. Large-scale genome-wide association studies have recently identified many loci that influence key human ageing traits, including lifespan. Multi-trait loci have been linked with several age-related diseases, suggesting shared ageing influences. Mutations that drive accelerated ageing in prototypical progeria syndromes in humans point to an important role for genome maintenance and stability. Together, these different strands of genetic research are highlighting pathways for the discovery of anti-ageing interventions that may be applicable in humans.

THE EXPOSOME IN HUMAN EVOLUTION: FROM DUST TO DIESEL

Global exposures to air pollution and cigarette smoke are novel in human evolutionary history and are associated with about 16 million premature deaths per year. We investigate the history of the human exposome for relationships between novel environmental toxins and genetic changes during human evolution in six phases. Phase I: With increased walking on savannas, early human ancestors inhaled crustal dust, fecal aerosols, and spores; carrion scavenging introduced new infectious pathogens. Phase II: Domestic fire exposed early Homo to novel toxins from smoke and cooking. Phases III and IV: Neolithic to preindustrial Homo sapiens incurred infectious pathogens from domestic animals and dense communities with limited sanitation. Phase V: Industrialization introduced novel toxins from fossil fuels, industrial chemicals, and tobacco at the same time infectious pathogens were diminishing. Thereby, pathogen-driven causes of mortality were replaced by chronic diseases driven by sterile inflammogens, exogenous and endogenous. Phase VI: Considers future health during global warming with increased air pollution and infections. We hypothesize that adaptation to some ancient toxins persists in genetic variations associated with inflammation and longevity.

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.

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.

The Genetics of Aging: A Vertebrate Perspective

Aging negatively impacts vitality and health. Many genetic pathways that regulate aging were discovered in invertebrates. However, the genetics of aging is more complex in vertebrates because of their specialized systems. This Review discusses advances in the genetic regulation of aging in vertebrates from work in mice, humans, and organisms with exceptional lifespans. We highlight challenges for the future, including sex-dependent differences in lifespan and the interplay between genes and environment. We also discuss how the identification of reliable biomarkers of age and development of new vertebrate models can be leveraged for personalized interventions to counter aging and age-related diseases.

APOE Alleles and Extreme Human Longevity

We assembled a collection of 28,297 participants from seven studies of longevity and healthy aging comprising New England Centenarian, Long Life Family, Longevity Gene Population, Southern Italian Centenarian, Japanese Centenarian, the Danish Longevity, and the Health and Retirement Studies to investigate the association between the APOE alleles ε2ε3 and ε4 and extreme human longevity and age at death. By using three different genetic models and two definitions of extreme longevity based on either a threshold model or age at death, we show that ε4 is associated with a substantially decreased odds for extreme longevity, and increased risk for death that persists even beyond ages reached by less than 1% of the population. We also show that carrying the ε2ε2 or ε2ε3 genotype is associated with significantly increased odds to reach extreme longevity, with decreased risk for death compared with carrying the genotype ε3ε3 but with only a modest reduction in risk for death beyond an age reached by less than 1% of the population.

Association of immunoglobulin GM allotypes with longevity in long-living individuals from Southern Italy

Background

The aim of this study was to analyse the role of GM allotypes, i.e. the hereditary antigenic determinants expressed on immunoglobulin polypeptide chains, in the attainment of longevity. The role played by immunoglobulin allotypes in the control of immune responses is well known as well as the role of an efficient immune response in longevity achievement. So, it is conceivable that particular GM allotypes may contribute to the generation of an efficient immune response that supports successful ageing, hence longevity.

Methods

In order to show if GM allotypes play a role in the achievement of longevity, we typed the DNA of 95 Long-living individuals (LLIs) and 96 young control individuals (YCs) from South Italy for GM3/17 and GM23+/− alleles.

Results

To demonstrate the role of GM allotypes in the attainment of longevity we compared genotype and allele frequencies of GM allotypes between LLIs and YCs. A global chi-square test (3 × 2) shows that the distribution of genotypes at the GM 3/17 locus is highly significantly different in LLIs from that observed in YCs (p < 0.0001). The 2 × 2 chi-square test shows that the carriers of the GM3 allele contribute to this highly significant difference. Accordingly, GM3 allele is significantly overrepresented in LLIs. No significant differences were instead observed regarding GM23 allele.

Conclusion

These preliminary results show that GM3 allotype is significantly overrepresented in LLIs. To best of our knowledge, this is the first study performed to assess the role of GM allotypes in longevity. So, it should be necessary to verify the data in a larger sample of individuals to confirm GM role in the attainment of longevity.