FOXO3
Forkhead box protein O3 (AF6q21 protein) (Forkhead in rhabdomyosarcoma-like 1) [FKHRL1] [FOXO3A]
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Late-onset asthma (LOA) is beginning to account for an increasing proportion of asthma patients, which is often underdiagnosed in the elderly. Studies on the possible relations between aging-related genes and LOA contribute to the diagnosis and treatment of LOA. Forkhead Box O3 (FOXO3) and TP53 are two classic aging-related genes. DNA methylation varies greatly with age which may play an important role in the pathogenesis of LOA. We supposed that the differentially methylated sites of FOXO3 and TP53 associated with clinical phenotypes of LOA may be useful biomarkers for the early screening of LOA. The mRNA expression and DNA methylation of FOXO3 and TP53 in peripheral blood of 43 LOA patients (15 mild LOA, 15 moderate LOA and 13 severe LOA) and 60 healthy controls (HCs) were determined. The association of methylated sites with age was assessed by Cox regression to control the potential confounders. Then, the correlation between differentially methylated sites (DMSs; p-value < 0.05) and clinical lung function in LOA patients was evaluated. Next, candidate DMSs combining with age were evaluated to predict LOA by receiver operating characteristic (ROC) analysis and principal components analysis (PCA). Finally, HDM-stressed asthma model was constructed, and DNA methylation inhibitor 5-Aza-2'-deoxycytidine (5-AZA) were used to determine the regulation of DNA methylation on the expression of FOXO3 and TP53. Compared with HCs, the mRNA expression and DNA methylation of FOXO3 and TP53 vary significantly in LOA patients. Besides, 8 DMSs from LOA patients were identified. Two of the DMSs, chr6:108882977 (FOXO3) and chr17:7591672 (TP53), were associated with the severity of LOA. The combination of the two DMSs and age could predict LOA with high accuracy (AUC values = 0.924). In HDM-stressed asthma model, DNA demethylation increased the expression of FOXO3 and P53. The mRNA expression of FOXO3 and TP53 varies significantly in peripheral blood of LOA patients, which may be due to the regulation of DNA methylation. FOXO3 and TP53 methylation is a suitable blood biomarker to predict LOA, which may be useful targets for the risk diagnosis and clinical management of LOA.
Keywords
- Aging
- DNA methylation
- FOXO3
- Late-onset asthma
- TP53
Neurodegenerative diseases (ND) have been linked to the critical process in aging-cellular senescence. However, the temporal dynamics of cellular senescence in ND conditions is unresolved. Here, we show senescence features develop in human Huntington's disease (HD) neural stem cells (NSCs) and medium spiny neurons (MSNs), including the increase of p16 , a key inducer of cellular senescence. We found that HD NSCs reprogram the transcriptional targets of FOXO3, a major cell survival factor able to repress cell senescence, antagonizing p16 expression via the FOXO3 repression of the transcriptional modulator ETS2. Additionally, p16 promotes cellular senescence features in human HD NSCs and MSNs. These findings suggest that cellular senescence may develop during neuronal differentiation in HD and that the FOXO3-ETS2-p16 axis may be part of molecular responses aimed at mitigating this phenomenon. Our studies identify neuronal differentiation with accelerated aging of neural progenitors and neurons as an alteration that could be linked to NDs.
Keywords
- neurodegenerative disease
- neuronal differentiation
- neuronal senescence
- response mechanisms
- temporal dynamics
Aging is characterized by a progressive deterioration in metabolic functions. The present study aimed to investigate the antagonistic effects of ginsenoside Rg1 (Rg1) on the γ-ray irradiation-induced aging of mixed hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs). C57BL/6 mice were divided into a control group, a γ-ray irradiation group that served as an aging mouse model, and an Rg1 group. The Rg1 group was treated with Rg1 at dosage of 20 mg/kg/day for 7 days prior to γ-ray irradiation. The aging mouse model was established by exposing the mice to 6.5-Gy γ-ray total-body irradiation. Stem cell antigen 1 positive (Sca-1 ) HSC/HPCs isolated from the mice were examined using a senescence-associated β-galactosidase (SA-β-Gal) staining assay. The cell cycle of the HSC/HPCs was examined using flow cytometry. A mixed hematopoietic progenitor cell colony-forming unit (CFU-mix) assay was also conducted. The mRNA and protein expression levels of sirtuin 1 (SIRT1), SIRT3, forkhead box O3 (FOXO3) and superoxide dismutase (SOD2) were evaluated using western blot and reverse transcription-quantitative PCR assays. The results indicated that Rg1 treatment significantly increased white blood cell, red blood cell and platelet counts in peripheral blood compared with those in the γ-ray irradiation group (P<0.05). However, Rg1 significantly attenuated the senescence of Sca-1 HSC/HPCs in the γ-ray irradiation aging mice model. The proportion of SA-β-Gal stained HSC/HPCs was significantly decreased and CFU-Mix counts were significantly increased in the Rg1 group compared with the γ-ray irradiation group (P<0.05). Rg1 significantly increased the mRNA and protein levels of SIRT1, SIRT3, FOXO3 and SOD2 in the Sca-1 HSC/HPCs compared with those in the γ-ray irradiation group (P<0.05). The percentage of Sca-1 HSC/HPCs arrested at the G1 phase in the Rg1 group was significantly decreased compared with that in the γ-ray irradiation group (P<0.05). In conclusion, the present study indicates that Rg1 exerts anti-aging effects via the regulation of SIRT1-FOXO3 and SIRT3-SOD2 signaling pathways, and triggering the progression of Sca-1 HSC/HPCs from the G1 phase to the S phase in γ-ray irradiation-induced aging mice.
Keywords
- SIRT1
- SIRT3
- aging
- ginsenoside Rg1
- hematopoietic progenitor cells
- hematopoietic stem cells
- senescence
- γ-ray irradiation
Ageing phenotypes, such as years lived in good health (healthspan), total years lived (lifespan), and survival until an exceptional old age (longevity), are of interest to us all but require exceptionally large sample sizes to study genetically. Here we combine existing genome-wide association summary statistics for healthspan, parental lifespan, and longevity in a multivariate framework, increasing statistical power, and identify 10 genomic loci which influence all three phenotypes, of which five (near FOXO3, SLC4A7, LINC02513, ZW10, and FGD6) have not been reported previously at genome-wide significance. The majority of these 10 loci are associated with cardiovascular disease and some affect the expression of genes known to change their activity with age. In total, we implicate 78 genes, and find these to be enriched for ageing pathways previously highlighted in model organisms, such as the response to DNA damage, apoptosis, and homeostasis. Finally, we identify a pathway worthy of further study: haem metabolism.
MeSH Terms
- Aging
- Gene Expression
- Genetic Predisposition to Disease
- Genome-Wide Association Study
- Heme
- Humans
- Longevity
- Multifactorial Inheritance
- Parents
- Phenotype
- Quantitative Trait Loci
- Sex Factors
In recent years, the scientific interest in natural compounds with geroprotective activities has grown exponentially. Among the various naturally derived molecules, astaxanthin (ASX) represents a highly promising candidate geroprotector. By virtue of the central polyene chain, ASX acts as a scavenger of free radicals in the internal membrane layer and simultaneously controls oxidation on the membrane surface. Moreover, several studies have highlighted ASX's ability to modulate numerous biological mechanisms at the cellular level, including the modulation of transcription factors and genes directly linked to longevity-related pathways. One of the main relevant evolutionarily-conserved transcription factors modulated by astaxanthin is the forkhead box O3 gene (FOXO3), which has been recognized as a critical controller of cell fate and function. Moreover, FOXO3 is one of only two genes shown to robustly affect human longevity. Due to its tropism in the brain, ASX has recently been studied as a putative neuroprotective molecule capable of delaying or preventing brain aging in different experimental models of brain damage or neurodegenerative diseases. Astaxanthin has been observed to slow down brain aging by increasing brain-derived neurotrophic factor (BDNF) levels in the brain, attenuating oxidative damage to lipids, protein, and DNA and protecting mitochondrial functions. Emerging data now suggest that ASX can modulate Nrf2, FOXO3, Sirt1, and Klotho proteins that are linked to longevity. Together, these mechanisms provide support for a role of ASX as a potential geroneuroprotector.
Keywords
- FOXO3
- NRF2
- SIRT1
- astaxanthin
- geroprotector
- longevity
- neuroprotection
Ageing is associated with disrupted redox signalling and increased circulating inflammatory cytokines. Skeletal muscle homeostasis depends on the balance between muscle hypertrophy, atrophy and regeneration, however during ageing this balance is disrupted. The molecular pathways underlying the age-related decline in muscle regenerative potential remain elusive. microRNAs are conserved robust gene expression regulators in all tissues including skeletal muscle. Here, we studied satellite cells from adult and old mice to demonstrate that inhibition of miR-21 in satellite cells from old mice improves myogenesis. We determined that increased levels of proinflammatory cytokines, TNFα and IL6, as well as H O , increased miR-21 expression in primary myoblasts, which in turn resulted in their decreased viability and myogenic potential. Inhibition of miR-21 function rescued the decreased size of myotubes following TNFα or IL6 treatment. Moreover, we demonstrated that miR-21 could inhibit myogenesis in vitro via regulating [[IL6R]], PTEN and FOXO3 signalling. In summary, upregulation of miR-21 in satellite cells and muscle during ageing may occur in response to elevated levels of TNFα and IL6, within satellite cells or myofibrillar environment contributing to skeletal muscle ageing and potentially a disease-related decline in potential for muscle regeneration.
Keywords
- IL6
- IL6R
- aging
- cachexia
- miR-21
- microRNA
- muscle
- regeneration
- sarcopenia
Mammalian species differ up to 100-fold in their aging rates and maximum lifespans. Long-lived mammals appear to possess traits that extend lifespan and healthspan. Genomic analyses have not revealed a single pro-longevity function that would account for all longevity effects. In contrast, it appears that pro-longevity mechanisms may be complex traits afforded by connections between metabolism and protein functions that are impossible to predict by genomic approaches alone. Thus, metabolomics and proteomics studies will be required to understand the mechanisms of longevity. Several examples are reviewed that demonstrate the naked mole rat (NMR) shows unique proteomic signatures that contribute to longevity by overcoming several hallmarks of aging. SIRT6 is also discussed as an example of a protein that evolves enhanced enzymatic function in long-lived species. Finally, it is shown that several longevity-related proteins such as Cip1/p21, FOXO3, TOP2A, AKT1, RICTOR, INSR, and SIRT6 harbor posttranslational modification (PTM) sites that preferentially appear in either short- or long-lived species and provide examples of crosstalk between PTM sites. Prospects of enhancing lifespan and healthspan of humans by altering metabolism and proteoforms with drugs that mimic changes observed in long-lived species are discussed.
Keywords
- SIRT6
- aging
- long-lived mammals
- naked mole rats
- proteomics
Chronic obstructive pulmonary disease (COPD) is a chronic lung inflammatory disease which has a close relationship with aging. Genome-wide analysis reveals that DNA methylation markers vary obviously with age. DNA methylation variations in peripheral blood have the potential to be biomarkers for COPD. However, the specific DNA methylation of aging-related genes in the peripheral blood of COPD patients remains largely unknown. Firstly, 9 aging-related differentially expressed genes (DEGs) in COPD patients were screened out from the 25 aging-related genes profile through a comprehensive screening strategy. Secondly, qPCR and multiple targeted bisulfite enrichment sequencing (MethTarget) were used to detect the mRNA level and DNA methylation level of the 9 differentially expressed genes in the peripheral blood of 60 control subjects and 45 COPD patients. The candidate functional CpG sites were selected on the basis of the regulation ability of the target gene expression. Thirdly, the correlation was evaluated between the DNA methylation level of the key CpG sites and the clinical parameters of COPD patients, including forced expiratory volume in one second (FEV1), forced expiratory volume in one second as percentage of predicted volume (FEV1%), forced expiratory volume/ forced vital capacity (FEV/FVC), modified British medical research council (mMRC) score, acute exacerbation frequency and the situation of frequent of acute aggravation (CAT) score. Lastly, differentially methylated CpG sites unrelated to smoking were also determined in COPD patients. Of the 9 differentially expressed aging-related genes, the mRNA expression of 8 genes were detected to be significantly down-regulated in COPD group, compared with control group. Meanwhile, the methylated level of all aging-related genes was changed in COPD group containing 219 COPD-related CpG sites in total. Notably, 27 CpG sites of FOXO3 gene showed a lower False Discovery Rate (FDR) and higher methylation difference values. Also, some variable DNA methylation is associated with the severity of COPD. Additionally, of the 219 COPD-related CpG sites, 147 CpG sites were not related to smoking. These results identified that the mRNA expression and DNA methylation level of aging-related genes were changed in male COPD patients, which provides a molecular link between aging and COPD. The identified CpG markers are associated with the severity of COPD and provide new insights into the prediction and identification of COPD.
MeSH Terms
- Adolescent
- Adult
- Age Factors
- Aged
- Aged, 80 and over
- Aging
- Case-Control Studies
- CpG Islands
- DNA Methylation
- Databases, Genetic
- Female
- Forced Expiratory Volume
- Forkhead Transcription Factors
- Genetic Predisposition to Disease
- Humans
- Lung
- Male
- Middle Aged
- Pulmonary Disease, Chronic Obstructive
- Risk Assessment
- Risk Factors
- Severity of Illness Index
- Sex Factors
- Transcriptome
- Vital Capacity
- Young Adult
Keywords
- Aging
- Aging-related genes
- COPD
- DNA methylation
A number of efforts are underway to better understand the role of genetic variation in successful aging and longevity. However, to date, only two genes have been consistently associated with longevity in humans: APOE and FOXO3, with the APOE ɛ2 allele also protective against dementia. Recently, using an exome-wide SNP array approach, a missense variant CLEC3B c.316G>A (rs13963 p.S106G) was reported to associate with longevity in two independent cohorts of Japanese and Chinese participants. Interestingly, CLEC3B p.S106G is more frequent in Caucasian populations. Herein, we examined the frequency of CLEC3B p.S106G in a Caucasian series of 1,483 neurologically healthy individuals with a specific subset >80 years of age. Although our findings do not support an association between CLEC3B p.S106G and aging without neurological disease (p = .89), we confirmed the association between the APOE ε2 allele and better survival without neurological disease (p = .001). Further assessment of healthy aged cohorts that retain intact neurological function will be critical to understand the etiology of neurodegenerative disease and the role of age at risk.
Keywords
APOE
CLEC3B
- Aging
- Human genetics
- Human health
Elevated uric acid (UA) is a key risk factor for many disorders, including metabolic syndrome, gout and kidney stones. Despite frequent occurrence of these disorders, the genetic pathways influencing UA metabolism and the association with disease remain poorly understood. In humans, elevated UA levels resulted from the loss of the of the urate oxidase (Uro) gene around 15 million years ago. Therefore, we established a Drosophila melanogaster model with reduced expression of the orthologous Uro gene to study the pathogenesis arising from elevated UA. Reduced Uro expression in Drosophila resulted in elevated UA levels, accumulation of concretions in the excretory system, and shortening of lifespan when reared on diets containing high levels of yeast extract. Furthermore, high levels of dietary purines, but not protein or sugar, were sufficient to produce the same effects of shortened lifespan and concretion formation in the Drosophila model. The insulin-like signaling (ILS) pathway has been shown to respond to changes in nutrient status in several species. We observed that genetic suppression of ILS genes reduced both UA levels and concretion load in flies fed high levels of yeast extract. Further support for the role of the ILS pathway in modulating UA metabolism stems from a human candidate gene study identifying SNPs in the ILS genes AKT2 and FOXO3 being associated with serum UA levels or gout. Additionally, inhibition of the NADPH oxidase (NOX) gene rescued the reduced lifespan and concretion phenotypes in Uro knockdown flies. Thus, components of the ILS pathway and the downstream protein NOX represent potential therapeutic targets for treating UA associated pathologies, including gout and kidney stones, as well as extending human healthspan.
MeSH Terms
- Animals
- Animals, Genetically Modified
- Cohort Studies
- Disease Models, Animal
- Drosophila melanogaster
- Feeding Behavior
- Female
- Gene Knockdown Techniques
- Gout
- Humans
- Insulin
- Kidney Calculi
- Longevity
- Male
- Metabolic Networks and Pathways
- Middle Aged
- NADPH Oxidases
- Polymorphism, Single Nucleotide
- Purines
- Signal Transduction
- Urate Oxidase
- Uric Acid
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. [i]FOXO3[/i] 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 [i]FOXO3[/i] variants located in intron 2. This haplotype block forms a putative aging chromatin hub in which [i]FOXO3[/i] 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 [i]FOXO3[/i] and its single-nucleotide polymorphisms (SNPs) in healthy aging, with a focus on the enhancer region encompassing the SNP [i]rs2802292[/i], which upregulates FOXO3 expression and can promote the activity of the aging hub in response to different stress stimuli. [i]FOXO3[/i] 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 [i]FOXO3[/i] association with longevity between genders, as its activity in females may be modulated by estrogens through estrogen receptor response elements located in the [i]rs2802292[/i]-encompassing region. Altogether, the molecular mechanisms described here may help establish whether the [i]rs2802292[/i] SNP can be taken advantage of in predictive medicine and define the potential of targeting FOXO3 for age-related diseases.
Keywords
- 3C, Chromosome conformation capture
- 5′UTR, Five prime untranslated region
- ACH, Active chromatin hub
- Aging
- Chromatin hub
- ER, Estrogen receptor
- ERE, Estrogen-responsive element
- FHRE, Forkhead response element
- FOXO3
- FOXO3, Forkhead box 3
- GPx, Glutathione peroxidase
- GWAS, Genome-wide association study
- HPS, Hamartomatous polyposis syndrome
- HSE, Heat shock element
- HSF1, Heat shock factor 1
- IGF-1, Insulin growth factor-1
- LD, Linkage disequilibrium
- Longevity
- PHTS, PTEN hamartoma tumor syndrome
- PJS, Peutz-Jeghers syndrome
- ROS, Reactive oxygen species
- SNP
- SNP, Single nucleotide polymorphism
- SNV, Single nucleotide variant
- SOD2, Superoxide dismutase 2
- TAD, Topologically associated domain
BACKGROUND This study aimed to investigate the association of single nucleotide polymorphisms (SNPs) of Forkhead box O3 (FOXO3) gene with type 2 diabetes mellitus (T2D). MATERIAL AND METHODS A total of 843 elderly residents from east China were enrolled in this study, which included 426 patients with type 2 diabetes and 417 controls. Four SNPs were analyzed by qPCR. Genotype frequencies of the 4 SNPs in FOXO3 of the patients and controls were analyzed using logistic regression analysis. The association between each SNP and clinical indicators was analyzed by linear regression analysis. RESULTS None of the 4 FOXO3 variants, rs13217795, rs2764264, rs2802292, and rs13220810, were associated with the risk of type 2 diabetes compared to controls. However, rs13217795, rs2764264, and rs2802292 were associated with lower blood glucose levels. Notably, further subgroup analysis indicated that the longevity-associated alleles of FOXO3 SNP (rs13217795, rs2764264, and rs2802292) were associated with lower blood glucose levels in women (TC versus TT, -0.724 mmol/L, P=0.005; CC versus TT, -1.093 mmol/L, P=0.03; TC versus TT, -0.801 mmol/L, P=0.002; CC versus TT, -1.212 mmol/L, P=0.001; TG versus TT, -0.754 mmol/L, P=0.004; and GG versus TT, -1.150 mmol/L, P=0.001) but not in men. CONCLUSIONS The results indicated that longevity-associated FOXO3 variants were correlated with lower blood glucose levels in elderly women with type 2 diabetes in east China.
MeSH Terms
- Aged
- Aged, 80 and over
- Asian Continental Ancestry Group
- Case-Control Studies
- China
- Diabetes Mellitus, Type 2
- Female
- Forkhead Box Protein O3
- Gene Frequency
- Genotype
- Humans
- Longevity
- Male
- Middle Aged
- Polymorphism, Single Nucleotide
Ageing is defined by the loss of functional reserve over time, leading to a decreased tissue homeostasis and increased age-related pathology. The accumulation of damage including DNA damage contributes to driving cell signaling pathways that, in turn, can drive different cell fates, including senescence and apoptosis, as well as mitochondrial dysfunction and inflammation. In addition, the accumulation of cell autonomous damage with time also drives ageing through non-cell autonomous pathways by modulation of signaling pathways. Interestingly, genetic and pharmacologic analysis of factors able to modulate lifespan and healthspan in model organisms and even humans have identified several key signaling pathways including IGF-1, NF-κB, FOXO3, mTOR, Nrf-2 and sirtuins. This review will discuss the roles of several of these key signaling pathways, in particular NF-κB and Nrf2, in modulating ageing and age-related diseases.
MeSH Terms
- Aging
- Animals
- Apoptosis
- Cellular Senescence
- Humans
- Longevity
- NF-E2-Related Factor 2
- NF-kappa B
- Signal Transduction
Keywords
- Age-related disease
- Apoptosis
- Inflammation
- NF-κB Nrf2
- Senescence
- Signaling pathways
- Sirtuins
FOXO3 has been consistently associated with longevity and with a reduction in the prevalence of cardiovascular disease. In this issue, Yan et al. (2019) report that FOXO3-activated vascular cells derived from human embryonic stem cells (ESCs) promote multiple vascular functions and reverse cellular aging through the transcriptional repression of CSRP1.
MeSH Terms
- Adolescent
- Cellular Senescence
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Humans
- Longevity
- Regeneration
Super-Seniors are healthy, long-lived individuals who were recruited at age 85 years or older with no history of cancer, cardiovascular disease, diabetes, dementia, or major pulmonary disease. In a 10-year follow-up, we aimed to determine whether surviving Super-Seniors showed compression of morbidity, and to test whether the allele frequencies of longevity-associated variants in APOE and FOXO3 were more extreme in such long-term survivors. Super-Seniors who survived and were contactable were re-interviewed 10 years after initial characterization. Health and lifestyle were characterized via questionnaire. Geriatric tests including the Timed Up and Go (TUG), Geriatric Depression Scale (GDS), Instrumental Activities of Daily Living (IADL) and the Mini-Mental State Exam (MMSE) were administered, and data were compared to results from on average 10 years earlier. As well, genotype and allele frequencies for SNPs rs7412 and rs429358 in APOE, and rs2802292 in FOXO3 were compared to the frequencies in the original collection of Super-Seniors and mid-life controls. Of the 480 Super-Seniors recruited from 2004 to 2007, 13 were alive, contactable, and consented to re-interview (mean age = 100.1 ± 3.3). Eight of these 13 participants (62%) still met Super-Senior health criteria. Diseases that occurred in late life were cardiovascular (5 of 13; 38%) and lung disease (1 of 13; 8%). MMSE and IADL scores declined in the decade between interviews, and GDS and TUG scores increased. The surviving group of centenarians had a higher frequency of APOE and FOXO3 longevity-associated variants even when compared to the original long-lived Super-Senior cohort. Although physical and mental decline occurred in the decade between interviews, the majority of Super-Seniors re-interviewed still met the original health criteria. These observations are consistent with reports of compression of morbidity at extreme ages, particularly in centenarians. The increased frequency of longevity- associated variants in this small group of survivors is consistent with studies that reported genetics as a larger contributor to longevity in older age groups.
MeSH Terms
- Activities of Daily Living
- Aged, 80 and over
- Aging
- Dementia
- Female
- Follow-Up Studies
- Genotype
- Humans
- Life Style
- Longevity
- Male
- Morbidity
- Polymorphism, Single Nucleotide
- Surveys and Questionnaires
- Time Factors
Keywords
- Centenarians
- Healthy aging
- Longevity
- Oldest-old
- Super-seniors
Innate immunity utilizes components of sensory signal transduction such as bitter and sweet taste receptors. In fact, empirical evidence has shown bitter and sweet taste receptors to be an integral component of antimicrobial immune response in upper respiratory tract infections. Since an efficient immune response plays a key role in the attainment of longevity, it is not surprising that the rs978739 polymorphism of the bitter taste receptor TAS2R16 gene has been shown to be associated with longevity in a population of 941 individuals ranging in age from 20 to 106 years from Calabria (Italy). There are many possible candidate genes for human longevity, however of the many genes tested, only APOE and FOXO3 survived to association in replication studies. So, it is necessary to validate in other studies genes proposed to be associated with longevity. Thus, we analysed the association of the quoted polymorphism in a population of long lived individuals (LLIs) and controls from another Italian population from Cilento. The analysis has been performed on data previously obtained with genome-wide association study on a population of LLIs (age range 90-109 years) and young controls (age range 18-45 years) from Cilento (Italy). Statistical power calculations showed that the analysed cohort represented by 410 LLIs and 553 young controls was sufficiently powered to replicate the association between rs978739 and the longevity phenotype according to the effect size and frequencies described in the previous paper, under a dominant and additive genetic model. However, no evidence of association between rs978739 and the longevity phenotype was observed according to the additive or dominant model. There are several reasons for the failure of the confirmation of a previous study. However, the differences between the two studies in terms of environment of the population adopted and of the criteria of inclusion have made difficult the replication of the findings.
Keywords
- Bitter taste receptors
- Case control study
- GWAS
- Innate immunity
- Longevity
- TAS2R16 gene
FOXO3 is an evolutionarily conserved transcription factor that has been linked to longevity. Here we wanted to find out whether human vascular cells could be functionally enhanced by engineering them to express an activated form of FOXO3. This was accomplished via genome editing at two nucleotides in human embryonic stem cells, followed by differentiation into a range of vascular cell types. FOXO3-activated vascular cells exhibited delayed aging and increased resistance to oxidative injury compared with wild-type cells. When tested in a therapeutic context, FOXO3-enhanced vascular cells promoted vascular regeneration in a mouse model of ischemic injury and were resistant to tumorigenic transformation both in vitro and in vivo. Mechanistically, constitutively active FOXO3 conferred cytoprotection by transcriptionally downregulating CSRP1. Taken together, our findings provide mechanistic insights into FOXO3-mediated vascular protection and indicate that FOXO3 activation may provide a means for generating more effective and safe biomaterials for cell replacement therapies.
MeSH Terms
- Adult
- Animals
- Cell Differentiation
- Disease Models, Animal
- Embryonic Stem Cells
- Endothelial Cells
- Forkhead Box Protein O3
- Genetic Engineering
- Humans
- Ischemia
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Inbred NOD
- Mice, Nude
- Mice, SCID
- Regeneration
Keywords
- FOXO3
- aging
- gene editing
- stem cell
- vascular cells
Next-generation DNA sequencing has ushered in a new era of genotype-phenotype comparisons that have the potential to elucidate the genetic nature of complex traits. Since such methods rely on short sequence reads and since the human genome is composed largely of repetitive DNA elements larger than these read lengths many results cannot be mapped and are discarded, thus eliminating a large portion of the genome from analysis. Discerning associations in complex traits, such as longevity, will require either longer read lengths or methods to address these sequence complexities. Whole genome analysis, such as Genome Wide Association Studies (GWAS), also suffers from the repetitive nature of the human genome, as there exist many gaps in the availability of useable genetic markers, often in interesting regulatory regions. Methods are described here whereby some of these problems have been addressed by targeted DNA sequencing, full exploitation of available public databases, and a careful evaluation of genomic features where we use the FOXO3 gene as an example to identify functional variations and how they may relate to longevity.
MeSH Terms
- Forkhead Box Protein O3
- Genetic Association Studies
- High-Throughput Nucleotide Sequencing
- Humans
- Longevity
- Polymerase Chain Reaction
- Polymorphism, Single Nucleotide
- Sequence Analysis, DNA
Keywords
- Genome complexity
- Long-range DNA sequencing
- Long-range PCR
- Repetitive DNA
The forkhead box O3 (FOXO3, or FKHRL1) protein is a member of the FOXO subclass of transcription factors. FOXO proteins were originally identified as regulators of insulin-related genes; however, they are now established regulators of genes involved in vital biological processes, including substrate metabolism, protein turnover, cell survival, and cell death. [i]FOXO3[/i] is one of the rare genes that have been consistently linked to longevity in [i]in vivo[/i] models. This review provides an update of the most recent research pertaining to the role of FOXO3 in (i) the regulation of protein turnover in skeletal muscle, the largest protein pool of the body, and (ii) the genetic basis of longevity. Finally, it examines (iii) the role of microRNAs in the regulation of FOXO3 and its impact on the regulation of the cell cycle.
MeSH Terms
- Cell Cycle
- Forkhead Box Protein O3
- Humans
- Longevity
- Muscle, Skeletal
Keywords
- FOXO3
- longevity
- microRNA
- protein turnover
- skeletal muscle
- transcription factor
Intervertebral disk (IVD) degeneration is a prevalent age-associated musculoskeletal disorder and a major cause of chronic low back pain. Aging is the main risk factor for the disease, but the molecular mechanisms regulating IVD homeostasis during aging are unknown. The aim of this study was to investigate the function of FOXO, a family of transcription factors linked to aging and longevity, in IVD aging and age-related degeneration. Conditional deletion of all FOXO isoforms (FOXO1, 3, and 4) in IVD using the Col2a1Cre and AcanCreER mouse resulted in spontaneous development of IVD degeneration that was driven by severe cell loss in the nucleus pulposus (NP) and cartilaginous endplates (EP). Conditional deletion of individual FOXO in mature mice showed that FOXO1 and FOXO3 are the dominant isoforms and have redundant functions in promoting IVD homeostasis. Gene expression analyses indicated impaired autophagy and reduced antioxidant defenses in the NP of FOXO-deficient IVD. In primary human NP cells, FOXO directly regulated autophagy and adaptation to hypoxia and promoted resistance to oxidative and inflammatory stress. Our findings demonstrate that FOXO are critical regulators of IVD homeostasis during aging and suggest that maintaining or restoring FOXO expression can be a therapeutic strategy to promote healthy IVD aging and delay the onset of IVD degeneration.
MeSH Terms
- Aging
- Animals
- Cells, Cultured
- Forkhead Box Protein O1
- Forkhead Box Protein O3
- Homeostasis
- Humans
- Intervertebral Disc
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
Keywords
- FOXO
- aging
- autophagy
- intervertebral disk
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.
MeSH Terms
- 5' Untranslated Regions
- Alleles
- Binding Sites
- Cell Line
- Cell Survival
- Cells, Cultured
- Enhancer Elements, Genetic
- Forkhead Box Protein O3
- Heat Shock Transcription Factors
- Humans
- Introns
- Longevity
- Polymorphism, Single Nucleotide
- Promoter Regions, Genetic
- Stress, Physiological
- Transcriptional Activation
FOXO3 is one of the most prominent genes demonstrating a consistently reproducible genetic association with human longevity. The mechanisms by which these individual gene variants confer greater organismal lifespan are not well understood. We assessed the effect of longevity-associated FOXO3 alleles on age-related leukocyte telomere dynamics in a cross-sectional study comprised of samples from 121 healthy Okinawan-Japanese donors aged 21-95 years. We found that telomere length for carriers of the longevity associated allele of FOXO3 single nucleotide polymorphism rs2802292 displayed no significant correlation with age, an effect that was most pronounced in older (>50 years of age) participants. This is the first validated longevity gene variant identified to date showing an association with negligible loss of telomere length with age in humans in a cross-sectional study. Reduced telomere attrition may be a key mechanism for the longevity-promoting effect of the FOXO3 genotype studied.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Alleles
- Asian Continental Ancestry Group
- Cross-Sectional Studies
- Female
- Forkhead Box Protein O3
- Genotype
- Heterozygote
- Humans
- Japan
- Leukocytes
- Longevity
- Male
- Middle Aged
- Polymorphism, Single Nucleotide
- Telomere Shortening
- Young Adult
The evolutionarily conserved FOXO family of transcription factors has emerged as a significant arbiter of neural cell fate and function in mammals. From the neural stem cell (NSC) state through mature neurons under both physiological and pathological conditions, they have been found to modulate neural cell survival, stress responses, lineage commitment, and neuronal signaling. Lineage-specific FOXO knockout mice have provided an invaluable tool for the dissection of FOXO biology in the nervous system. Within the NSC compartments of the brain, FOXOs are required for the maintenance of NSC quiescence and for the clearance of reactive oxygen species. Within mature neurons, FOXO transcriptional activity is essential for the prevention of age-dependent axonal degeneration. Acutely, FOXO3 has been found to cause axonal degeneration upon withdrawal of neurotrophic factors. In more active neural signaling, FOXO6 promotes increased dendritic spine density of hippocampal neurons and is required for the consolidation of memories. In addition to the central nervous system (CNS), FOXOs also influence the functionality of the peripheral nervous system (PNS). FOXO1 knockout within the PNS results in a reduction of sympathetic tone and decreased levels of brain-derived norepinephrine and lower energy expenditure. FOXO3 knockout mice have impaired hearing which may be due to defects in synapse localization within the ear. Given the scope of FOXO activities in both the CNS and PNS, it will be of interest to study FOXOs within the context of neurodegenerative diseases such as Alzheimer's, Parkinson's, Huntington's, and amyotrophic lateral sclerosis. From within the nervous system, FOXOs may also regulate important parameters such as whole-body metabolism, motor function, and catecholamine production, making FOXOs key players in physiologic homeostasis.
MeSH Terms
- Animals
- Apoptosis
- Forkhead Transcription Factors
- Gene Expression Regulation
- Humans
- Mice
- Nervous System
- Neural Stem Cells
- Neurodegenerative Diseases
- Neurons
Keywords
- Aging
- FOXO
- Knockout
- Nervous system
- Neural stem cell
- Neurodegeneration
- Neurodevelopment
- Neurosignaling
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.
MeSH Terms
- Aged
- Aged, 80 and over
- Apolipoproteins E
- Cardiovascular Diseases
- Cohort Studies
- Depression
- Diabetes Mellitus
- Female
- Forkhead Box Protein O3
- Genotype
- Health Status
- Humans
- Longevity
- Male
- Membrane Transport Proteins
- Polymorphism, Single Nucleotide
- Self Report
- Sweden
FOXO3 is consistently annotated as a human longevity gene. However, functional variants and underlying mechanisms for the association remain unknown. Here, we perform resequencing of the FOXO3 locus and single-nucleotide variant (SNV) genotyping in three European populations. We find two FOXO3 SNVs, rs12206094 and rs4946935, to be most significantly associated with longevity and further characterize them functionally. We experimentally validate the in silico predicted allele-dependent binding of transcription factors (CTCF, SRF) to the SNVs. Specifically, in luciferase reporter assays, the longevity alleles of both variants show considerable enhancer activities that are reversed by IGF-1 treatment. An eQTL database search reveals that the alleles are also associated with higher FOXO3 mRNA expression in various human tissues, which is in line with observations in long-lived model organisms. In summary, we present experimental evidence for a functional link between common intronic variants in FOXO3 and human longevity.
MeSH Terms
- Age Factors
- Aged
- Aged, 80 and over
- Alleles
- CCCTC-Binding Factor
- Computer Simulation
- European Continental Ancestry Group
- Female
- Forkhead Box Protein O3
- Haplotypes
- Humans
- Insulin-Like Growth Factor I
- Introns
- Longevity
- Male
- Middle Aged
- Polymorphism, Single Nucleotide
- RNA, Messenger
- Serum Response Factor
Previous studies note specific FOXO3 single-nucleotide polymorphisms (SNPs) associated with human longevity. However, it is not clear if these SNPs influence mortality risk beyond the oldest 1 percentile of survival. Using data from four longevity studies (total n = 8,266, age range 96-119 years for cases), we tested gene-wide association between 107 SNPs and survival to at least the oldest 1 percentile of survival for the 1900 birth cohort (≥96, white males; ≥100 white females). This analysis replicated 17 previously published variants, several of which are significant expression quantitative trait loci of FOXO3; rs6911407 and rs2253310 have the most significant effect on FOXO3 expressions in brain tissue. We then performed a survival analysis to determine if any of these 107 SNPs impact upon mortality risk beyond the oldest 1 percentile. While none of the 17 published variants was significantly associated with mortality risk beyond this extreme age, an uncommon homozygote genotype of rs9384680 exhibited the strongest association with mortality risk (p = 2.68E-04) in only 11 females, a heretofore unreported association. These analyses replicate the previous association of common variants of FOXO3 with older age but these common variants do not modify risk for mortality at ages beyond the oldest 1 percentile age of survival.
MeSH Terms
- Aged, 80 and over
- Alleles
- Case-Control Studies
- Female
- Forkhead Box Protein O3
- Genetic Association Studies
- Genotype
- Hippocampus
- Homozygote
- Humans
- Longevity
- Male
- Polymorphism, Single Nucleotide
- Survival Analysis
Several pathologies such as neurodegeneration and cancer are associated with aging, which is affected by many genetic and environmental factors. Healthy aging conceives human longevity, possibly due to carrying the defensive genes. For instance, FOXO (forkhead box O) genes determine human longevity. FOXO transcription factors are involved in the regulation of longevity phenomenon via insulin and insulin-like growth factor signaling. Only one FOXO gene (FOXO DAF-16) exists in invertebrates, while four FOXO genes, that is, FOXO1, FOXO3, FOXO4, and FOXO6 are found in mammals. These four transcription factors are involved in the multiple cellular pathways, which regulate growth, stress resistance, metabolism, cellular differentiation, and apoptosis in mammals. However, the accurate mode of longevity by FOXO factors is unclear until now. This article describes briefly the existing knowledge that is related to the role of FOXO factors in human longevity.
MeSH Terms
- Forkhead Transcription Factors
- Humans
- Longevity
- Oxidative Stress
- Phosphorylation
- Signal Transduction
FOXO3 has been implicated in longevity in multiple populations. By DNA sequencing in long-lived individuals, we identified all single nucleotide polymorphisms (SNPs) in FOXO3 and showed 41 were associated with longevity. Thirteen of these had predicted alterations in transcription factor binding sites. Those SNPs appeared to be in physical contact, via RNA polymerase II binding chromatin looping, with sites in the FOXO3 promoter, and likely function together as a cis-regulatory unit. The SNPs exhibited a high degree of LD in the Asian population, in which they define a specific longevity haplotype that is relatively common. The haplotype was less frequent in whites and virtually nonexistent in Africans. We identified distant contact points between FOXO3 and 46 neighboring genes, through long-range physical contacts via CCCTC-binding factor zinc finger protein (CTCF) binding sites, over a 7.3 Mb distance on chromosome 6q21. When activated by cellular stress, we visualized movement of FOXO3 toward neighboring genes. FOXO3 resides at the center of this early-replicating and highly conserved syntenic region of chromosome 6. Thus, in addition to its role as a transcription factor regulating gene expression genomewide, FOXO3 may function at the genomic level to help regulate neighboring genes by virtue of its central location in chromatin conformation via topologically associated domains. We believe that the FOXO3 'interactome' on chromosome 6 is a chromatin domain that defines an aging hub. A more thorough understanding of the functions of these neighboring genes may help elucidate the mechanisms through which FOXO3 variants promote longevity and healthy aging.
MeSH Terms
- African Continental Ancestry Group
- Aged
- Aged, 80 and over
- Asian Continental Ancestry Group
- Base Sequence
- Binding Sites
- Case-Control Studies
- Chromatin
- Chromosomes, Human, Pair 6
- European Continental Ancestry Group
- Female
- Forkhead Box Protein O3
- Genome, Human
- Haplotypes
- Healthy Aging
- Heat-Shock Proteins
- Humans
- Laminin
- Longevity
- Male
- Membrane Proteins
- Phenotype
- Polymorphism, Single Nucleotide
- Protein Binding
- Ubiquitin-Protein Ligases
Keywords
FOXO3
- fluorescence in situ hybridization
- gene-gene interactions
- single nucleotide polymorphisms
- transcription factor binding
Helping neurons to compensate for proteotoxic stress and maintain function over time (neuronal compensation) has therapeutic potential in aging and neurodegenerative disease. The stress response factor FOXO3 is neuroprotective in models of Huntington's disease (HD), Parkinson's disease and motor-neuron diseases. Neuroprotective compounds acting in a FOXO-dependent manner could thus constitute bona fide drugs for promoting neuronal compensation. However, whether FOXO-dependent neuroprotection is a common feature of several compound families remains unknown. Using drug screening in C. elegans nematodes with neuronal expression of human exon-1 huntingtin (128Q), we found that 3ß-Methoxy-Pregnenolone (MAP4343), 17ß-oestradiol (17ßE2) and 12 flavonoids including isoquercitrin promote neuronal function in 128Q nematodes. MAP4343, 17ßE2 and isoquercitrin also promote stress resistance in mutant Htt striatal cells derived from knock-in HD mice. Interestingly, daf-16/FOXO is required for MAP4343, 17ßE2 and isoquercitrin to sustain neuronal function in 128Q nematodes. This similarly applies to the GSK3 inhibitor lithium chloride (LiCl) and, as previously described, to resveratrol and the AMPK activator metformin. Daf-16/FOXO and the targets engaged by these compounds define a sub-network enriched for stress-response and neuronally-active pathways. Collectively, these data highlights the dependence on a daf-16/FOXO-interaction network as a common feature of several compound families for prolonging neuronal function in HD.
MeSH Terms
- Aging
- Animals
- Animals, Genetically Modified
- Caenorhabditis elegans
- Caenorhabditis elegans Proteins
- Drug Evaluation, Preclinical
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Gene Expression Regulation
- Gene Knock-In Techniques
- Humans
- Huntingtin Protein
- Huntington Disease
- Lithium Chloride
- Mice
- Neurons
- Pregnenolone
- Quercetin
Aging is a main risk factor for intervertebral disc (IVD) degeneration, the main cause of low back pain. FOXO transcription factors are important regulators of tissue homeostasis and longevity. Here, we determined the expression pattern of FOXO in healthy and degenerated human IVD and the associations with IVD degeneration during mouse aging. FOXO expression was assessed by immunohistochemistry in normal and degenerated human IVD samples and in cervical and lumbar IVD from 6-, 12-, 24-, and 36-month-old C57BL/6J mice. Mouse spines were graded for key histological features of disc degeneration in all the time points and expression of two key FOXO downstream targets, sestrin 3 (SESN3) and superoxide dismutase (SOD2), was assessed by immunohistochemistry. Histological analysis revealed that FOXO proteins are expressed in all compartments of human and mouse IVD. Expression of FOXO1 and FOXO3, but not FOXO4, was significantly deceased in human degenerated discs. In mice, degenerative changes in the lumbar spine were seen at 24 and 36 months of age whereas cervical IVD showed increased histopathological scores at 36 months. FOXO expression was significantly reduced in lumbar IVD at 12-, 24-, and 36-month-old mice and in cervical IVD at 36-month-old mice when compared with the 6-month-old group. The reduction of FOXO expression in lumbar IVD was concomitant with a decrease in the expression of SESN3 and SOD2. These findings suggest that reduced FOXO expression occurs in lumbar IVD during aging and precedes the major histopathological changes associated with lumbar IVD degeneration. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2682-2691, 2017.
MeSH Terms
- Aged
- Aging
- Animals
- Forkhead Box Protein O1
- Forkhead Box Protein O3
- Humans
- Intervertebral Disc
- Intervertebral Disc Degeneration
- Male
- Mice, Inbred C57BL
- Middle Aged
Keywords
- FOXO
- aging
- intervertebral disc
Accumulation of damaged DNA in hematopoietic stem cells (HSC) is associated with chromosomal abnormalities, genomic instability, and HSC aging and might promote hematological malignancies with age. Despite this, the regulatory pathways implicated in the HSC DNA damage response have not been fully elucidated. One of the sources of DNA damage is reactive oxygen species (ROS) generated by both exogenous and endogenous insults. Balancing ROS levels in HSC requires FOXO3, which is an essential transcription factor for HSC maintenance implicated in HSC aging. Elevated ROS levels result in defective [i]Foxo3[/i] HSC cycling, among many other deficiencies. Here, we show that loss of FOXO3 leads to the accumulation of DNA damage in primitive hematopoietic stem and progenitor cells (HSPC), associated specifically with reduced expression of genes implicated in the repair of oxidative DNA damage. We provide further evidence that [i]Foxo3[/i] HSPC are defective in DNA damage repair. Specifically, we show that the base excision repair pathway, the main pathway utilized for the repair of oxidative DNA damage, is compromised in [i]Foxo3[/i] primitive hematopoietic cells. Treating mice [i]in vivo[/i] with [i]N[/i]-acetylcysteine reduces ROS levels, rescues HSC cycling defects, and partially mitigates HSPC DNA damage. These results indicate that DNA damage accrued as a result of elevated ROS in [i]Foxo3[/i] mutant HSPC is at least partially reversible. Collectively, our findings suggest that FOXO3 serves as a protector of HSC genomic stability and health.
MeSH Terms
- Acetylcysteine
- Animals
- Cell Cycle
- DNA Damage
- Forkhead Box Protein O3
- Hematopoietic Stem Cells
- Mice
- Mice, Inbred C57BL
- Oxidative Stress
- Reactive Oxygen Species
Keywords
- DNA damage response
- FOXO
- FOXO3
- ROS
- aging
- base excision repair (BER)
- hematopoietic stem cells
- oxidative DNA damage
- oxidative stress
- reactive oxygen species (ROS)
Age-associated immunological dysfunction (immunosenescence) is closely linked to perturbation of the gut microbiota. Here, we investigated whether syringaresinol (SYR), a polyphenolic lignan, modulates immune aging and the gut microbiota associated with this effect in middle-aged mice. Compared with age-matched control mice, SYR treatment delayed immunosenescence by enhancing the numbers of total CD3 T cells and naïve T cells. SYR treatment induced the expression of Bim as well as activation of FOXO3 in Foxp3 regulatory T cells (Tregs). Furthermore, SYR treatment significantly enhanced the Firmicutes/Bacteroidetes ratio compared with that in age-matched controls by increasing beneficial bacteria, Lactobacillus and Bifidobacterium, while reducing the opportunistic pathogenic genus, Akkermansia. In addition, SYR treatment reduced the serum level of lipopolysaccharide-binding protein, an inflammatory marker, and enhanced humoral immunity against influenza vaccination to the level of young control mice. Taken together, these findings suggest that SYR may rejuvenate the immune system through modulation of gut integrity and microbiota diversity as well as composition in middle-aged mice, which may delay the immunosenescence associated with aging.
MeSH Terms
- Aging
- Animals
- Area Under Curve
- Bifidobacterium
- CD3 Complex
- Female
- Forkhead Box Protein O3
- Furans
- Gastrointestinal Microbiome
- Immunosenescence
- Lactobacillus
- Lignans
- Male
- Mice, Inbred C57BL
- Mice, Inbred ICR
- Rats, Sprague-Dawley
- T-Lymphocyte Subsets
- Verrucomicrobia
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.
MeSH Terms
- Case-Control Studies
- China
- Female
- Forkhead Box Protein O3
- Haplotypes
- Humans
- Linkage Disequilibrium
- Longevity
- Male
- Polymorphism, Single Nucleotide
Having longer lived parents has been shown to be an important predictor of health trajectories and life span. As such, parental life span is an important phenotype that may uncover genes that affect longevity. A genome-wide association study of parental life span in participants of European and African ancestry from the Health and Retirement Study was conducted. A genome-wide significant association was observed for rs35715456 (log10BF = 6.3) on chromosome 18 for the dichotomous trait of having at least one long-lived parent versus not having any long-lived parent. This association was not replicated in an independent sample from the InCHIANTI and Framingham Heart Study. The most significant association among single nucleotide polymorphisms in longevity candidate genes (APOE, MINIPP1, FOXO3, EBF1, CAMKIV, and OTOL1) was observed in the EBF1 gene region (rs17056207, p = .0002). A promising genetic signal for parental life span was identified but was not replicated in independent samples.
MeSH Terms
- Aged
- Aged, 80 and over
- Chromosomes, Human, Pair 18
- Female
- Genome-Wide Association Study
- Humans
- Longevity
- Male
- Middle Aged
- Parents
- Phenotype
- Polymorphism, Single Nucleotide
- Trans-Activators
Keywords
- Epidemiology
- Genetics
- Life span
- Public health
- Successful aging
We recently reported that protection against coronary artery disease (CAD) mortality is the major contributor to longer life associated with FOXO3 genotype. The present study examined this relation in more detail. We performed a 15-year observational study of 3,584 older American men of Japanese ancestry from the Kuakini Honolulu Heart Program cohort and 1,595 White and 1,067 Black elderly individuals from the Health Aging and Body Composition study. Multivariate Cox regression models demonstrated that carriage of the longevity-associated G allele of FOXO3 single nucleotide polymorphisms rs2802292 was a protective factor against CAD mortality in all three populations. In Japanese and Whites, but not in Blacks, the protective effect of the G allele was little changed in models adjusted for other major risk factors. Population-attributable risk (PAR) models found that the nonprotective TT genotype contributed 15%, 9%, and 3% to CAD mortality risk in Japanese, White, and Black Americans, respectively, and was one of the top three contributing factors to CAD mortality. In Japanese, this effect size was comparable with hypertension (15%), but in Whites and Blacks PAR for hypertension was higher (29% and 26%, respectively). G-allele carriers had lower plasma TNF-α than noncarriers, suggesting inflammation as a potential mediating factor for CAD mortality risk. FOXO3 genotype is an important risk factor for CAD mortality in older populations. More research is needed to identify potential mechanisms and targets for intervention.
MeSH Terms
- African Americans
- Aged
- Aged, 80 and over
- Asian Americans
- Coronary Artery Disease
- European Continental Ancestry Group
- Forkhead Box Protein O3
- Genotype
- Humans
- Japan
- Longevity
- Male
- Middle Aged
- Polymorphism, Single Nucleotide
- Prospective Studies
- Risk Factors
- United States
Keywords
- Coronary artery disease
- Genetic
- Inflammation
- Longevity
- Mortality
The growth hormone/insulin-like growth factor (IGF) axis can be manipulated in animal models to promote longevity, and IGF-related proteins including IGF-I and IGF-binding protein-3 (IGFBP-3) have also been implicated in risk of human diseases including cardiovascular diseases, diabetes, and cancer. Through genomewide association study of up to 30 884 adults of European ancestry from 21 studies, we confirmed and extended the list of previously identified loci associated with circulating IGF-I and IGFBP-3 concentrations (IGF1, IGFBP3, GCKR, TNS3, GHSR, FOXO3, ASXL2, NUBP2/IGFALS, SORCS2, and CELSR2). Significant sex interactions, which were characterized by different genotype-phenotype associations between men and women, were found only for associations of IGFBP-3 concentrations with SNPs at the loci IGFBP3 and SORCS2. Analyses of SNPs, gene expression, and protein levels suggested that interplay between IGFBP3 and genes within the NUBP2 locus (IGFALS and HAGH) may affect circulating IGF-I and IGFBP-3 concentrations. The IGF-I-decreasing allele of SNP rs934073, which is an eQTL of ASXL2, was associated with lower adiposity and higher likelihood of survival beyond 90 years. The known longevity-associated variant rs2153960 (FOXO3) was observed to be a genomewide significant SNP for IGF-I concentrations. Bioinformatics analysis suggested enrichment of putative regulatory elements among these IGF-I- and IGFBP-3-associated loci, particularly of rs646776 at CELSR2. In conclusion, this study identified several loci associated with circulating IGF-I and IGFBP-3 concentrations and provides clues to the potential role of the IGF axis in mediating effects of known (FOXO3) and novel (ASXL2) longevity-associated loci.
MeSH Terms
- Adult
- Aging
- Female
- Gene Expression Regulation
- Genome-Wide Association Study
- Humans
- Insulin-Like Growth Factor Binding Protein 3
- Insulin-Like Growth Factor I
- Male
- Metabolome
- Quantitative Trait Loci
- Quantitative Trait, Heritable
- Regulatory Sequences, Nucleic Acid
Keywords
- IGF-I
- IGFBP-3
- aging
- genomewide association study
- growth hormone axis
- longevity
Recent research in nutritional control of aging suggests that cytosolic increases in the reduced form of nicotinamide adenine dinucleotide and decreasing nicotinamide adenine dinucleotide metabolism plays a central role in controlling the longevity gene products sirtuin 1 (SIRT1), adenosine monophosphate-activated protein kinase (AMPK) and forkhead box O3 (FOXO3). High nutrition conditions, such as the diabetic milieu, increase the ratio of reduced to oxidized forms of cytosolic nicotinamide adenine dinucleotide through cascades including the polyol pathway. This redox change is associated with insulin resistance and the development of diabetic complications, and might be counteracted by insulin C-peptide. My research and others' suggest that the SIRT1-liver kinase B1-AMPK cascade creates positive feedback through nicotinamide adenine dinucleotide synthesis to help cells cope with metabolic stress. SIRT1 and AMPK can upregulate liver kinase B1 and FOXO3, key factors that help residential stem cells cope with oxidative stress. FOXO3 directly changes epigenetics around transcription start sites, maintaining the health of stem cells. 'Diabetic memory' is likely a result of epigenetic changes caused by high nutritional conditions, which disturb the quiescent state of residential stem cells and impair tissue repair. This could be prevented by restoring SIRT1-AMPK positive feedback through activating FOXO3.
MeSH Terms
- AMP-Activated Protein Kinases
- Aging
- Animals
- C-Peptide
- Diabetes Complications
- Diabetic Angiopathies
- Disease Models, Animal
- Epigenesis, Genetic
- Feedback, Physiological
- Forkhead Box Protein O3
- Humans
- Hypoxia
- Insulin Resistance
- NAD
- Oxidation-Reduction
- Oxidative Stress
- Signal Transduction
- Sirtuin 1
Keywords
- Adenosine monophosphate-activated protein kinase
- C-peptide
- Sirtuin 1
The G allele of the FOXO3 single nucleotide polymorphism (SNP) rs2802292 exhibits a consistently replicated genetic association with longevity in multiple populations worldwide. The aims of this study were to quantify the mortality risk for the longevity-associated genotype and to discover the particular cause(s) of death associated with this allele in older Americans of diverse ancestry. It involved a 17-year prospective cohort study of 3584 older American men of Japanese ancestry from the Honolulu Heart Program cohort, followed by a 17-year prospective replication study of 1595 white and 1056 black elderly individuals from the Health Aging and Body Composition cohort. The relation between FOXO3 genotype and cause-specific mortality was ascertained for major causes of death including coronary heart disease (CHD), cancer, and stroke. Age-adjusted and multivariable Cox proportional hazards models were used to compute hazard ratios (HRs) for all-cause and cause-specific mortality. We found G allele carriers had a combined (Japanese, white, and black populations) risk reduction of 10% for total (all-cause) mortality (HR = 0.90; 95% CI, 0.84-0.95; P = 0.001). This effect size was consistent across populations and mostly contributed by 26% lower risk for CHD death (HR = 0.74; 95% CI, 0.64-0.86; P = 0.00004). No other causes of death made a significant contribution to the survival advantage for G allele carriers. In conclusion, at older age, there is a large risk reduction in mortality for G allele carriers, mostly due to lower CHD mortality. The findings support further research on FOXO3 and FoxO3 protein as potential targets for therapeutic intervention in aging-related diseases, particularly cardiovascular disease.
MeSH Terms
- Age Factors
- Aged
- Alleles
- Cause of Death
- Cohort Studies
- Coronary Artery Disease
- European Continental Ancestry Group
- Female
- Forkhead Box Protein O3
- Genetic Predisposition to Disease
- Heterozygote
- Humans
- Male
- Mortality
- Multivariate Analysis
- Risk Factors
- Tumor Necrosis Factor-alpha
Keywords
- FOXO3
- heart disease
- longevity
- mortality
FOXO3, AKT1 and IGF-2R are critical members of the insulin/IGF-1 signaling pathway. Previous studies showed that polymorphisms (SNPs) in FOXO3, AKT1 and IGF-2R were associated with human longevity in Caucasian population. However, the association of these SNPs in different ethnic groups is often inconsistent. Here, we investigated the association of genetic variants in three genes with human longevity in Han Chinese population. Twelve SNPs from FOXO3, AKT1 and IGF-2R were selected and genotyped in 1202 long-lived individuals (nonagenarians and centenarians) and younger individuals. Rs9486902 of FOXO3 was found to be associated with human longevity in both genders combined in this study (allelic P = 0.002, corrected P = 0.024). The other eleven SNPs were not significantly associated with human longevity in Han Chinese population. The haplotypes TTCTT, CCTTC and CTCCT of FOXO3 as well as GGTCGG and GGTCAG of AKT1 were shown to have a significant difference between case and control (P =0.006, 2.78×10-5, 4.68×10-6, 0.003,0.005, respectively). The estimated prevalence of diabetes and prediabetes in long-lived individuals was significantly lower than in common adult populations (P = 0.001, 2.3×10-26) .Therefore, the search for longevity-associated genes provides the identification of new potential targets beneficial for the treatment of diabetes.
MeSH Terms
- Adult
- Aged, 80 and over
- Asian Continental Ancestry Group
- China
- Diabetes Mellitus
- Female
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Gene Frequency
- Genotype
- Haplotypes
- Humans
- Linkage Disequilibrium
- Longevity
- Male
- Polymorphism, Single Nucleotide
- Prediabetic State
- Prevalence
- Proto-Oncogene Proteins c-akt
- Receptor, IGF Type 2
- Young Adult
Keywords
- AKT1
- FOXO3
- Gerotarget
- IGF-2R
- human longevity
- single nucleotide polymorphism (SNP)
The exceptional longevity phenotype, defined as living beyond the age of 95, results from complex interactions between environmental and genetic factors. Epigenetic mechanisms, such as DNA methylation and histone modifications, mediate the interaction of these factors. This review will provide an overview of animal model studies used to examine age-related epigenetic modifications. Key human studies will be used to illustrate the progress made in the identification of the genetic loci associated with exceptional longevity, including APOE and FOXO3 and genes/loci that are also differentially methylated between long-lived individuals and younger controls. Future studies should focus on elucidating whether identified longevity genetic loci directly influence epigenetic mechanisms, especially on differentially methylated regions associated with longevity.
MeSH Terms
- Aging
- Animals
- Biomarkers
- Chromatin Assembly and Disassembly
- DNA Methylation
- Epigenesis, Genetic
- Genetic Association Studies
- Genetic Predisposition to Disease
- Genome-Wide Association Study
- Histones
- Humans
- Longevity
- Neurodegenerative Diseases
- Prognosis
- RNA, Untranslated
Keywords
- DNA methylation
- aging
- epigenetic
- genome-wide association studies
- histone modification
- longevity
- neurodegenerative disease
Aging constitutes the key risk factor for age-related diseases such as cancer and cardiovascular and neurodegenerative disorders. Human longevity and healthy aging are complex phenotypes influenced by both environmental and genetic factors. The fact that genetic contribution to lifespan strongly increases with greater age provides basis for research on which "protective genes" are carried by long-lived individuals. Studies have consistently revealed FOXO (Forkhead box O) transcription factors as important determinants in aging and longevity. FOXO proteins represent a subfamily of transcription factors conserved from Caenorhabditis elegans to mammals that act as key regulators of longevity downstream of insulin and insulin-like growth factor signaling. Invertebrate genomes have one FOXO gene, while mammals have four FOXO genes: FOXO1, FOXO3, FOXO4, and FOXO6. In mammals, this subfamily is involved in a wide range of crucial cellular processes regulating stress resistance, metabolism, cell cycle arrest, and apoptosis. Their role in longevity determination is complex and remains to be fully elucidated. Throughout this review, the mechanisms by which FOXO factors contribute to longevity will be discussed in diverse animal models, from Hydra to mammals. Moreover, compelling evidence of FOXOs as contributors for extreme longevity and health span in humans will be addressed.
MeSH Terms
- Aging
- Animals
- Forkhead Transcription Factors
- Humans
- Longevity
- Models, Animal
- Signal Transduction
Keywords
- FOXO transcription factors
- aging
- animal models
- insulin and IGF-1 signaling pathway
- longevity
The minor alleles of 3 FOXO3 single nucleotide polymorphisms (SNPs)- rs2802292 , rs2253310 , and rs2802288 -are associated with human longevity. The aim of the present study was to test these SNPs for association with blood pressure (BP) and essential hypertension (EHT). In a primary study involving Americans of Japanese ancestry drawn from the Family Blood Pressure Program II we genotyped 411 female and 432 male subjects aged 40-79 years and tested for statistical association by contingency table analysis and generalized linear models that included logistic regression adjusting for sibling correlation in the data set. Replication of rs2802292 with EHT was attempted in Japanese SONIC study subjects and of each SNP in a meta-analysis of genome-wide association studies of BP in individuals of European ancestry. In Americans of Japanese ancestry, women homozygous for the longevity-associated (minor) allele of each FOXO3 SNP had 6mm Hg lower systolic BP and 3mm Hg lower diastolic BP compared with major allele homozygotes (Bonferroni corrected P < 0.05 and >0.05, respectively). Frequencies of minor allele homozygotes were 3.3-3.9% in women with EHT compared with 9.5-9.6% in normotensive women ( P = 0.03-0.04; haplotype analysis P = 0.0002). No association with BP or EHT was evident in males. An association with EHT was seen for the minor allele of rs2802292 in the Japanese SONIC cohort ( P = 0.03), while in European subjects the minor allele of each SNP was associated with higher systolic and diastolic BP. Longevity-associated FOXO3 variants may be associated with lower BP and EHT in Japanese women.
MeSH Terms
- Adult
- Aged
- Blood Pressure
- Blood Pressure Determination
- Essential Hypertension
- Female
- Forkhead Box Protein O3
- Genome-Wide Association Study
- Genotype
- Humans
- Hypertension
- Longevity
- Middle Aged
- Polymorphism, Single Nucleotide
Hematopoietic stem cells (HSC) are primarily dormant but have the potential to become highly active on demand to reconstitute blood. This requires a swift metabolic switch from glycolysis to mitochondrial oxidative phosphorylation. Maintenance of low levels of reactive oxygen species (ROS), a by-product of mitochondrial metabolism, is also necessary for sustaining HSC dormancy. Little is known about mechanisms that integrate energy metabolism with hematopoietic stem cell homeostasis. Here, we identify the transcription factor FOXO3 as a new regulator of metabolic adaptation of HSC. ROS are elevated in Foxo3(-/-) HSC that are defective in their activity. We show that Foxo3(-/-) HSC are impaired in mitochondrial metabolism independent of ROS levels. These defects are associated with altered expression of mitochondrial/metabolic genes in Foxo3(-/-) hematopoietic stem and progenitor cells (HSPC). We further show that defects of Foxo3(-/-) HSC long-term repopulation activity are independent of ROS or mTOR signaling. Our results point to FOXO3 as a potential node that couples mitochondrial metabolism with HSC homeostasis. These findings have critical implications for mechanisms that promote malignant transformation and aging of blood stem and progenitor cells.
MeSH Terms
- Aging
- Animals
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Hematopoietic Stem Cells
- Homeostasis
- Mice
- Mitochondria
- Oxidative Stress
- Reactive Oxygen Species
- TOR Serine-Threonine Kinases
Keywords
- FOXO3
- HSC
- ROS
- metabolism
- mitochondria
MicroRNAs are critical post-transcriptional regulators of hematopoietic cell-fate decisions, though little remains known about their role in aging hematopoietic stem cells (HSCs). We found that the microRNA-212/132 cluster (Mirc19) is enriched in HSCs and is upregulated during aging. Both overexpression and deletion of microRNAs in this cluster leads to inappropriate hematopoiesis with age. Enforced expression of miR-132 in the bone marrow of mice led to rapid HSC cycling and depletion. A genetic deletion of Mirc19 in mice resulted in HSCs that had altered cycling, function, and survival in response to growth factor starvation. We found that miR-132 exerted its effect on aging HSCs by targeting the transcription factor FOXO3, a known aging associated gene. Our data demonstrate that Mirc19 plays a role in maintaining balanced hematopoietic output by buffering FOXO3 expression. We have thus identified it as a potential target that might play a role in age-related hematopoietic defects.
MeSH Terms
- Aging
- Animals
- Apoptosis
- Bone Marrow Cells
- Cell Differentiation
- Cell Line
- Cell Survival
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Gene Expression Regulation
- Hematopoiesis
- Hematopoietic Stem Cells
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- MicroRNAs
- Stem Cell Factor
Glucose homeostasis is a trait of healthy ageing and is crucial to the elderly, but less consideration has been given to the age composition in most studies involving genetics and hyperglycemia. Seven variants in FOXO3 were genotyped in three cohorts (n = 2037; LLI, MI_S and MI_N; mean age: 92.5 ± 3.6, 45.9 ± 8.2 and 46.8 ± 10.3, respectively) to compare the contribution of FOXO3 to fasting hyperglycemia (FH) between long-lived individuals (LLI, aged over 90 years) and middle-aged subjects (aged from 35-65 years). A different genetic predisposition of FOXO3 alleles to FH was observed between LLI and both of two middle-aged cohorts. In the LLI cohort, the longevity beneficial alleles of three variants with the haplotype "AGGC" in block 1 were significantly protective to FH, fasting glucose, hemoglobin A1C and HOMA-IR. Notably, combining multifactor dimensionality reduction and logistic regression, we identified a significant 3-factor interaction model (rs2802288, rs2802292 and moderate physical activity) associated with lower FH risk. However, not all of the findings were replicated in the two middle-aged cohorts. Our data provides a novel insight into the inconsistent genetic determinants between middle-aged and LLI subjects. FOXO3 might act as a shared genetic predisposition to hyperglycemia and lifespan.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Blood Glucose
- Cross-Sectional Studies
- Fasting
- Female
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Gene Expression
- Genetic Predisposition to Disease
- Glycated Hemoglobin A
- Humans
- Hyperglycemia
- Insulin
- Insulin Resistance
- Logistic Models
- Longevity
- Male
- Middle Aged
- Multifactor Dimensionality Reduction
Vitamin E has been suggested as nutritional intervention for the prevention of degenerative and age-related diseases. In this study, we aimed to elucidate the underlying mechanism of tocotrienol-rich fraction (TRF) in delaying cellular aging by targeting the proliferation signaling pathways in human diploid fibroblasts (HDFs). Tocotrienol-rich fraction was used to treat different stages of cellular aging of primary human diploid fibroblasts viz. young (passage 6), pre-senescent (passage 15) and senescent (passage 30). Several selected targets involved in the downstream of PI3K/AKT and RAF/MEK/ERK pathways were compared in total RNA and protein. Different transcriptional profiles were observed in young, pre-senescent and senescent HDFs, in which cellular aging increased AKT, FOXO3, CDKN1A and RSK1 mRNA expression level, but decreased ELK1, FOS and SIRT1 mRNA expression level. With tocotrienol-rich fraction treatment, gene expression of AKT, FOXO3, ERK and RSK1 mRNA was decreased in senescent cells, but not in young cells. The three down-regulated mRNA in cellular aging, ELK1, FOS and SIRT1, were increased with tocotrienol-rich fraction treatment. Expression of FOXO3 and P21Cip1 proteins showed up-regulation in senescent cells but tocotrienol-rich fraction only decreased P21Cip1 protein expression in senescent cells. Tocotrienol-rich fraction exerts gene modulating properties that might be responsible in promoting cell cycle progression during cellular aging.
MeSH Terms
- Antioxidants
- Cell Proliferation
- Cells, Cultured
- Cellular Senescence
- Diploidy
- Fibroblasts
- Humans
- Tocotrienols
- Vitamin E
Keywords
- Cellular aging
- Gene expression
- Human diploid fibroblasts
- Tocotrienol-rich fraction
- Vitamin E
Forkhead box class O (FOXO) transcription factors play a crucial role in longevity across species. Several polymorphisms in FOXO3 were previously reported to be associated with human longevity. However, only one Chinese replication study has been performed so far. To verify the role of FOXO3 in southern Chinese in the Red River Basin, a community-based case-control study was conducted, and seven polymorphisms were genotyped in 1336 participants, followed by a meta-analysis of eight case-control studies that included 5327 longevity cases and 4608 controls. In our case-control study, we found rs2802288*A and rs2802292*G were beneficial to longevity after Bonferroni correction (pallele = 0.005, OR = 1.266; pallele = 0.026, OR = 1.207). In addition, in the longevity group, carriers with rs2802288*A and rs2802292*G presented reduced HbA1c (p = 0.001), and homozygotes of rs2802292*GG presented improved HOMA-IR (p = 0.014). The meta-analysis further revealed the overall contribution of rs2802288*A and rs2802292*G to longevity. However, our stratified analysis revealed that rs2802292*G might act more strongly in Asians than Europeans, for enhancement of longevity. In conclusion, our study provides convincing evidence for a significant association between the rs2802288*A and rs2802292*G gene variants in FOXO3 and human longevity, and adds the Southern Chinese in the Red River Basin to the growing number of human replication populations.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Asian Continental Ancestry Group
- Case-Control Studies
- Female
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Genotype
- Humans
- Longevity
- Male
- Middle Aged
- Polymorphism, Single Nucleotide
The gene FOXO3, encoding the transcription factor forkhead box O-3 (FoxO3), is one of only two for which genetic polymorphisms have exhibited consistent associations with longevity in diverse human populations. Here, we review the multitude of actions of FoxO3 that are relevant to health, and thus healthy ageing and longevity. The study involved a literature search for articles retrieved from PubMed using FoxO3 as keyword. We review the molecular genetics of FOXO3 in longevity, then current knowledge of FoxO3 function relevant to ageing and lifespan. We describe how FoxOs are involved in energy metabolism, oxidative stress, proteostasis, apoptosis, cell cycle regulation, metabolic processes, immunity, inflammation and stem cell maintenance. The single FoxO in Hydra confers immortality to this fresh water polyp, but as more complex organisms evolved, this role has been usurped by the need for FoxO to control a broader range of specialized pathways across a wide spectrum of tissues assisted by the advent of as many as 4 FoxO subtypes in mammals. The major themes of FoxO3 are similar, but not identical, to other FoxOs and include regulation of cellular homeostasis, particularly of stem cells, and of inflammation, which is a common theme of age-related diseases. Other functions concern metabolism, cell cycle arrest, apoptosis, destruction of potentially damaging reactive oxygen species and proteostasis. The mechanism by which longevity-associated alleles of FOXO3 reduce age-related mortality is currently of great clinical interest. The prospect of optimizing FoxO3 activity in humans to increase lifespan and reduce age-related diseases represents an exciting avenue of clinical investigation. Research strategies directed at developing therapeutic agents that target FoxO3, its gene and proteins in the pathway(s) FoxO3 regulates should be encouraged and supported.
MeSH Terms
- Animals
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Humans
- Longevity
Multipotent skin-derived precursors (SKPs) are dermal stem cells with the capacity to reconstitute the dermis and other tissues, such as muscles and the nervous system. Thus, the easily available human SKPs (hSKPs) hold great promises in regenerative medicine. However, long-term expansion is difficult for hSKPs in vitro. We previously demonstrated that hSKPs senesced quickly under routine culture conditions. To identify the underlying mechanisms so as to find an effective way to expand hSKPs, time-dependent microarray analysis of gene expression in hSKPs during in vitro culture was performed. We found that the senescence of hSKPs had a unique gene expression pattern that differs from reported typical senescence. Subsequent investigation ruled out the role of DNA damage and classical p53 and p16(INK4a) signaling in hSKP senescence. Examination of cyclin-dependent kinase inhibitors revealed the involvement of p15(INK4b) and p27(KIP1). Further exploration about upstream signals indicated the contribution of Akt hypo-activity and FOXO3 to hSKP senescence. Forced activation of Akt and knockdown of FOXO3, p15(INK4b) and p27(KIP1) effectively inhibited hSKP senescence and promoted hSKP proliferation. The unique senescent phenotype of human dermal stem cells and the role of Akt-FOXO3-p27(KIP1)/p15(INK4b) signaling in regulating hSKP senescence provide novel insights into the senescence and self-renewal regulation of adult stem cells. The present study also points out a way to propagate hSKPs in vitro so as to fulfill their promises in regenerative medicine.
MeSH Terms
- Aging
- Cell Proliferation
- Cells, Cultured
- Cyclin-Dependent Kinase Inhibitor p15
- Cyclin-Dependent Kinase Inhibitor p27
- Cyclin-Dependent Kinases
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Humans
- Proto-Oncogene Proteins c-akt
- Signal Transduction
- Skin
- Stem Cells
Aging is a natural process involving complex interplay between environment, metabolism, and genes. Sirtuin genes and their downstream targets have been associated with lifespan in numerous organisms from nematodes to humans. Several target proteins of the sirtuin genes are key sensors and/or effectors of oxidative stress pathways including FOXO3, SOD3, and AKT1. To examine the relationship between single nucleotide polymorphisms (SNP) at candidate genes in these pathways and human lifespan, we performed a molecular epidemiologic study of an elderly cohort (≥65 years old.). Using age at death as a continuous outcome variable and assuming a co-dominant genetic model within the framework of multi-variable linear regression analysis, the genotype-specific adjusted mean age at death was estimated for individual SNP genotypes while controlling for age-related risk factors including smoking, body mass index, alcohol consumption and co-morbidity. Significant associations were detected between human lifespan and SNPs in genes SIRT3, SIRT5, SIRT6, FOXO3 and SOD3. Individuals with either the CC or CT genotype at rs107251 within SIRT6 displayed >5-year mean survival advantages compared to the TT genotype (5.5 and 5.9 years, respectively; q-value = 0.012). Other SNPs revealed genotype-specific mean survival advantages ranging from 0.5 to 1.6 years. Gender also modified the effect of SNPs in SIRT3, SIRT5 and AKT1 on lifespan. Our novel findings highlight the impact of sirtuins and sirtuin-related genotypes on lifespan, the importance of evaluating gender and the advantage of using age as a continuous variable in analyses to report mean age at death.
MeSH Terms
- Aged
- Aged, 80 and over
- Female
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Humans
- Longevity
- Male
- Polymorphism, Single Nucleotide
- Proto-Oncogene Proteins c-akt
- Sex Factors
- Sirtuins
- Superoxide Dismutase
Human lifespan is determined greatly by genetic factors and some investigations have identified putative genes implicated in human longevity. Although some genetic loci have been associated with longevity, most of them are difficult to replicate due to ethnic differences. In this study, we analyzed the association of 18 reported gene single nucleotide polymorphisms (SNPs) with longevity in 1075 samples consisting of 567 nonagenarians/centenarians and 508 younger controls using the GenomeLab SNPstream Genotyping System. Our results confirm the association of the forkhead box O3 (FOXO3) variant (rs13217795) and the ATM serine/threonine kinase (ATM) variant (rs189037) genotypes with longevity (p=0.0075 and p=0.026, using the codominant model and recessive model, respectively). Of note is that we first revealed the association of insulin-like growth factor binding protein 3 (IGFBP-3) gene polymorphism rs11977526 with longevity in Chinese nonagenarians/centenarians (p=0.033 using the dominant model and p=0.035 using the overdominant model). The FOXO3 and IGFBP-3 form important parts of the insulin/insulin-like growth factor-1 signaling pathway (IGF-1) implicated in human longevity, and the ATM gene is involved in sensing DNA damage and reducing oxidative stress, therefore our results highlight the important roles of insulin pathway and oxidative stress in the longevity in the Chinese population.
MeSH Terms
- Age Factors
- Aged, 80 and over
- Asian Continental Ancestry Group
- Ataxia Telangiectasia Mutated Proteins
- Case-Control Studies
- China
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Gene Frequency
- Genotype
- Humans
- Insulin-Like Growth Factor Binding Protein 3
- Longevity
- Phenotype
- Polymorphism, Single Nucleotide
E2F1 and FOXO3 are two transcription factors that have been shown to participate in cellular senescence. Previous report reveals that E2F1 enhanced cellular senescence in human fibroblast cells, while FOXO transcription factors play against senescence by regulation reactive oxygen species scavenging proteins. However, their functional interplay has been unclear. Here we use E2F1 knock-out murine Embryonic fibroblasts (MEFs), knockdown RNAi constructs, and ectopic expression of E2F1 to show that it functions by negatively regulating FOXO3. E2F1 attenuates FOXO3-mediated expression of MnSOD and Catalase without affecting FOXO3 protein stability, subcellular localization, or phosphorylation by Akt. We mapped the interaction between E2F1 and FOXO3 to a region including the DNA binding domain of E2F1 and the C-terminal transcription-activation domain of FOXO3. We propose that E2F1 inhibits FOXO3-dependent transcription by directly binding FOXO3 in the nucleus and preventing activation of its target genes. Moreover, knockdown of the Caenorhabditis elegans E2F1 ortholog efl-1 significantly extends lifespan in a manner that requires the activity of the C. elegans FOXO gene daf-16. We conclude that there is an evolutionarily conserved signaling connection between E2F1 and FOXO3, which regulates cellular senescence and aging by regulating the activity of FOXO3. We speculate that drugs and/or therapies that inhibit this physical interaction might be good candidates for reducing cellular senescence and increasing longevity.
MeSH Terms
- Aging
- Animals
- Binding Sites
- Caenorhabditis elegans
- Caenorhabditis elegans Proteins
- Catalase
- Cell Line
- Cellular Senescence
- E2F Transcription Factors
- E2F1 Transcription Factor
- Embryo, Mammalian
- Fibroblasts
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Gene Expression Regulation, Developmental
- HEK293 Cells
- Humans
- Longevity
- Mice
- Protein Binding
- Protein Interaction Domains and Motifs
- RNA, Small Interfering
- Signal Transduction
- Superoxide Dismutase
- Transcription Factors
Keywords
- E2F Transcription Factor
- FOXO
- Oxidative Stress
- Senescence
- Transcription Regulation
Logistic regression analysis based on data from 822 Han Chinese oldest old aged 92 demonstrated that interactions between carrying FOXO1A-266 or FOXO3-310 or FOXO3-292 and tea drinking at around age 60 or at present time were significantly associated with lower risk of cognitive disability at advanced ages. Associations between tea drinking and reduced cognitive disability were much stronger among carriers of the genotypes of FOXO1A-266 or FOXO3-310 or FOXO3-292 compared with noncarriers, and it was reconfirmed by analysis of three-way interactions across FOXO genotypes, tea drinking at around age 60, and at present time. Based on prior findings from animal and human cell models, we postulate that intake of tea compounds may activate FOXO gene expression, which in turn may positively affect cognitive function in the oldest old population. Our empirical findings imply that the health benefits of particular nutritional interventions, including tea drinking, may, in part, depend upon individual genetic profiles.
MeSH Terms
- Aged, 80 and over
- Aging
- Alleles
- Asian Continental Ancestry Group
- China
- Cognition
- Cognition Disorders
- Drinking Behavior
- Evidence-Based Medicine
- Female
- Forkhead Box Protein O1
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Gene Expression
- Genotype
- Humans
- Longitudinal Studies
- Male
- Phenotype
- Risk Factors
- Surveys and Questionnaires
- Tea
Keywords
- Cognitive disability
- FOXO genotypes
- GxE interactions
- Oldest old.
- Tea drinking
To determine the relation between height, FOXO3 genotype and age of death in humans. Observational study of 8,003 American men of Japanese ancestry from the Honolulu Heart Program/Honolulu-Asia Aging Study (HHP/HAAS), a genetically and culturally homogeneous cohort followed for over 40 years. A Cox regression model with age as the time scale, stratified by year of birth, was used to estimate the effect of baseline height on mortality during follow-up. An analysis of height and longevity-associated variants of the key regulatory gene in the insulin/IGF-1 signaling (IIS) pathway, FOXO3, was performed in a HHP-HAAS subpopulation. A study of fasting insulin level and height was conducted in another HHP-HAAS subpopulation. A positive association was found between baseline height and all-cause mortality (RR = 1.007; 95% CI 1.003-1.011; P = 0.002) over the follow-up period. Adjustments for possible confounding variables reduced this association only slightly (RR = 1.006; 95% CI 1.002-1.010; P = 0.007). In addition, height was positively associated with all cancer mortality and mortality from cancer unrelated to smoking. A Cox regression model with time-dependent covariates showed that relative risk for baseline height on mortality increased as the population aged. Comparison of genotypes of a longevity-associated single nucleotide polymorphism in FOXO3 showed that the longevity allele was inversely associated with height. This finding was consistent with prior findings in model organisms of aging. Height was also positively associated with fasting blood insulin level, a risk factor for mortality. Regression analysis of fasting insulin level (mIU/L) on height (cm) adjusting for the age both data were collected yielded a regression coefficient of 0.26 (95% CI 0.10-0.42; P = 0.001). Height in mid-life is positively associated with mortality, with shorter stature predicting longer lifespan. Height was, moreover, associated with fasting insulin level and the longevity genotype of FOXO3, consistent with a mechanistic role for the IIS pathway.
MeSH Terms
- Aged
- Asian Americans
- Body Height
- Fasting
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Genotype
- Humans
- Insulin
- Longevity
- Male
- Middle Aged
- Polymorphism, Single Nucleotide
- Proportional Hazards Models
In June 2013, a workshop was convened in San Francisco to explore, in depth, the role of the Forkhead transcription factor FOXO3 (and related FOXOs) in development, aging, and, in particular, exceptional longevity. The presentations covered results derived from model systems, computational analysis and bioinformatics, and genomics and genome-wide association studies of a number of cohorts. Although the data collectively strongly reinforce FOXO3 and the FOXO/FOXO3 pathway as very important determinants in aging and life span, much of the detail of how the latter is achieved still remains unknown, in part, because of the very large number of genes (~2,200 in Caenorhabditis elegans) the transcription factor is involved in helping regulate. Particularly challenging at the present time is understanding the association of apparently nonfunctional specific variants (single nucleotide polymorphisms) of FOXO3 and exceptional longevity in humans, a finding replicated in a number of studies. Nonetheless, as summarized in this report, valuable information and insights were presented at the workshop on the transcription factor including but not limited to its role in determining longevity in C elegans and Drosophila (in flies, eg, an important interaction in aging occurs between dFOXO and the transforming growth factor-β/activin pathway), stem cell function and aging (notably in hematopoiesis), downstream regulatory activity (eg, by binding near sites of RNAse occupancy and altering chromatin structure), and as a potential target for the development a healthy aging drug (in this example, using compounds developed and screened to effect FOXO function in cancer cells).
MeSH Terms
- Aging
- Animals
- Biomarkers
- Evidence-Based Medicine
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Genomics
- Humans
- Longevity
- Phenotype
- Polymorphism, Single Nucleotide
- San Francisco
- Transcription Factors
- Transforming Growth Factor beta
Keywords
- Aging
- FOXO3
- Longevity
- Transcription factor.
Aging is a major risk factor for osteoarthritis (OA). Forkhead-box class O (FoxO) transcription factors regulate mechanisms of cellular aging, including protein quality control, autophagy and defenses against oxidative stress. The objective of this study was to analyze FoxO transcription factors in normal, aging and OA cartilage. Knee joints from humans ages 23-90 and from mice at the age of 4-24 months and following surgically induced OA were analyzed for expression of FoxO proteins. Regulation of FoxO protein expression and activation was analyzed in cultured chondrocytes. Human cartilage expressed FOXO1 and FOXO3 but not FOXO4 proteins. FOXO1 and FOXO3 were more strongly expressed the superficial and mid zone as compared to the deep zone and were mainly localized in nuclei. During human joint aging, expression of FOXO1 and FOXO3 was markedly reduced in the superficial zone of cartilage regions exposed to maximal weight bearing. In OA cartilage, chondrocyte clusters showed strong FOXO phosphorylation and cytoplasmic localization. Similar patterns of FOXO expression in normal joints and changes in aging and OA were observed in mouse models. In cultured chondrocytes, IL-1β and TNF-α suppressed FOXO1, while TGF-β and PDGF increased FOXO1 and FOXO3 expression. FOXO1 and FOXO3 phosphorylation was increased by IL-1β, PDGF, bFGF, IGF-1, and the oxidant t-BHP. Normal articular cartilage has a tissue specific signature of FoxO expression and activation and this is profoundly altered in aging and OA in humans and mice. Changes in FoxO expression and activation may be involved in cartilage aging and OA.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Animals
- Arthritis, Experimental
- Cartilage, Articular
- Cell Cycle Proteins
- Cells, Cultured
- Chondrocytes
- Forkhead Box Protein O1
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Humans
- Knee Joint
- Mice
- Middle Aged
- Osteoarthritis, Knee
- Phosphorylation
- Transcription Factors
- Young Adult
Keywords
- Aging
- Cartilage
- FoxO
- Osteoarthritis
The insulin-like signaling pathway maintains a relatively short wild-type lifespan in Caenorhabditis elegans by phosphorylating and inactivating DAF-16, the ortholog of the FOXO transcription factors of mammalian cells. DAF-16 is phosphorylated by the AKT kinases, preventing its nuclear translocation. Calcineurin (PP2B phosphatase) also limits the lifespan of C. elegans, but the mechanism through which it does so is unknown. Herein, we show that TAX-6•CNB-1 and UNC-43, the C. elegans Calcineurin and Ca(2 )/calmodulin-dependent kinase type II (CAMKII) orthologs, respectively, also regulate lifespan through DAF-16. Moreover, UNC-43 regulates DAF-16 in response to various stress conditions, including starvation, heat or oxidative stress, and cooperatively contributes to lifespan regulation by insulin signaling. However, unlike insulin signaling, UNC-43 phosphorylates and activates DAF-16, thus promoting its nuclear localization. The phosphorylation of DAF-16 at S286 by UNC-43 is removed by TAX-6•CNB-1, leading to DAF-16 inactivation. Mammalian FOXO3 is also regulated by CAMKIIA and Calcineurin. DOI:http://dx.doi.org/10.7554/eLife.00518.001.
MeSH Terms
- Animals
- Caenorhabditis elegans
- Caenorhabditis elegans Proteins
- Calcineurin
- Calcium-Calmodulin-Dependent Protein Kinase Type 2
- Cell Nucleus
- Forkhead Transcription Factors
- Oxidative Stress
- Phosphorylation
- Protein Binding
- Protein Transport
- Transcription Factors
Keywords
- C. elegans
- CAMKII
- DAF-16
- FOXO
- aging
- calcineurin
- lifespan
Evidence from model organisms suggests that the insulin/IGF-1 signaling pathway has an important, evolutionarily conserved influence over rate of aging and thus longevity. In humans, the FOXO3 gene is the only widely replicated insulin/IGF-1 signaling pathway gene associated with longevity across multiple populations. Therefore, we conducted a nested case-control study of other insulin/IGF-1 signaling genes and longevity, utilizing a large, homogeneous, long-lived population of American men of Japanese ancestry, well characterized for aging phenotypes. Genotyping was performed of single nucleotide polymorphisms, tagging most of the genetic variation across several genes in the insulin/IGF-1 signaling pathway or related gene networks that may be influenced by FOXO3, namely, ATF4, CBL, CDKN2, EXO1, and JUN. Two initial, marginal associations with longevity did not remain significant after correction for multiple comparisons, nor were they correlated with aging-related phenotypes.
MeSH Terms
- Activating Transcription Factor 4
- Aged, 80 and over
- Aging
- Asian Americans
- Case-Control Studies
- Cohort Studies
- DNA Repair Enzymes
- Exodeoxyribonucleases
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Gene Frequency
- Genes, jun
- Genes, p16
- Genetic Variation
- Genotype
- Humans
- Insulin
- Insulin Resistance
- Insulin-Like Growth Factor I
- Japan
- Longevity
- Longitudinal Studies
- Male
- Polymorphism, Genetic
- Polymorphism, Single Nucleotide
- Proto-Oncogene Proteins c-cbl
- Signal Transduction
Keywords
- Human.
- Insulin signaling genes
- Longevity
- Molecular genetics
Progressive accumulation of defective mitochondria is a common feature of aged cells. SIRT3 is a NAD( )-dependent protein deacetylase that regulates mitochondrial function and metabolism in response to caloric restriction and stress. FOXO3 is a direct target of SIRT3 and functions as a forkhead transcription factor to govern diverse cellular responses to stress. Here we show that hydrogen peroxide induces SIRT3 to deacetylate FOXO3 at K271 and K290, followed by the upregulation of a set of genes that are essential for mitochondrial homeostasis (mitochondrial biogenesis, fission/fusion, and mitophagy). Consequently, SIRT3-mediated deacetylation of FOXO3 modulates mitochondrial mass, ATP production, and clearance of defective mitochondria. Thus, mitochondrial quantity and quality are ensured to maintain mitochondrial reserve capacity in response to oxidative damage. Maladaptation to oxidative stress is a major risk factor underlying aging and many aging-related diseases. Hence, our finding that SIRT3 deacetylates FOXO3 to protect mitochondria against oxidative stress provides a possible direction for aging-delaying therapies and disease intervention.
MeSH Terms
- Acetylation
- Aging
- Animals
- Aorta
- Caloric Restriction
- Cattle
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Human Umbilical Vein Endothelial Cells
- Humans
- Mitochondria
- Oxidation-Reduction
- Oxidative Stress
- Protein Interaction Maps
- Reactive Oxygen Species
- Sirtuin 3
Keywords
- Aging
- BAEC
- CR
- EC
- FOXO3
- Free radicals
- HUVEC
- Mitochondrial biogenesis
- Mitochondrial fission/fusion
- Mitochondrial homeostasis
- Mitophagy
- OCR
- Oxidative stress
- ROS
- SIRT3
- bovine aortic endothelial cell
- caloric restriction
- endothelial cell
- human umbilical vein endothelial cell
- oxygen consumption rate
- reactive oxygen species
Sirtuin 1 (SIRT1) regulates inflammation, aging (life span and health span), calorie restriction/energetics, mitochondrial biogenesis, stress resistance, cellular senescence, endothelial functions, apoptosis/autophagy, and circadian rhythms through deacetylation of transcription factors and histones. SIRT1 level and activity are decreased in chronic inflammatory conditions and aging, in which oxidative stress occurs. SIRT1 is regulated by a NAD( )-dependent DNA repair enzyme, poly(ADP-ribose) polymerase-1 (PARP1), and subsequent NAD( ) depletion by oxidative stress may have consequent effects on inflammatory and stress responses as well as cellular senescence. SIRT1 has been shown to undergo covalent oxidative modifications by cigarette smoke-derived oxidants/aldehydes, leading to posttranslational modifications, inactivation, and protein degradation. Furthermore, oxidant/carbonyl stress-mediated reduction of SIRT1 leads to the loss of its control on acetylation of target proteins including p53, RelA/p65, and FOXO3, thereby enhancing the inflammatory, prosenescent, and apoptotic responses, as well as endothelial dysfunction. In this review, the mechanisms of cigarette smoke/oxidant-mediated redox posttranslational modifications of SIRT1 and its roles in PARP1 and NF-κB activation, and FOXO3 and eNOS regulation, as well as chromatin remodeling/histone modifications during inflammaging, are discussed. Furthermore, we have also discussed various novel ways to activate SIRT1 either directly or indirectly, which may have therapeutic potential in attenuating inflammation and premature senescence involved in chronic lung diseases.
MeSH Terms
- Active Transport, Cell Nucleus
- Animals
- Cellular Senescence
- Forkhead Box Protein O3
- Forkhead Transcription Factors
- Histones
- Humans
- Inflammation
- NF-kappa B
- Nitric Oxide Synthase Type III
- Oxidation-Reduction
- Oxidative Stress
- Poly (ADP-Ribose) Polymerase-1
- Poly(ADP-ribose) Polymerases
- Signal Transduction
- Sirtuin 1
- Transcription Factor RelA
Keywords
- COPD
- FOXO3
- Free radicals
- GSH
- Inflammation
- NF-κB
- Oxidants
- Redox signaling
- SIRT1
- Senescence
- Tobacco smoke
FOXO3 is a member of the FOXO (forkhead box class O) transcription factor family and has roles in cell cycle control, apoptosis, neural and hematopoietic cell differentiation and DNA repair among other functions. Several human studies provide evidence for an association between aging, longevity and variation in FOXO3. Recently variation has been identified in exon 2 of ovine FOXO3. This exon encodes the C-terminus of the DNA-binding domain and a transcription activation domain that is the key regulator of transcriptional activity in target genes. The association of genetic variation in exon 2 with lifespan was investigated in 1,732 New Zealand (NZ) sheep. Of the seven haplotypes detected, the presence of the D haplotype, which codes for an amino acid substitution (a conserved methionine residue is replaced by a valine) at residue 407, is associated with a decrease of 0.39 years in mean age (P = 0.034). Significant differences in mean age were also detected between genotypes containing D (AD: 4.7 ± 0.21; BD: 4.7 ± 0.25) and genotypes that did not contain D (AA: 5.1 ± 0.14; AB: 4.9 ± 0.18; BB: 5.3 ± 0.25). Other genotypes were rare in the sheep investigated and were not analyzed. This suggests that genetic variation in ovine FOXO3 influences the lifespan of sheep either directly or indirectly by impacting on factors that lead to reduced productivity and increased likelihood of culling.
MeSH Terms
- Alleles
- Amino Acid Motifs
- Amino Acid Sequence
- Animals
- Forkhead Transcription Factors
- Gene Frequency
- Gene Order
- Haplotypes
- Longevity
- Molecular Sequence Data
- Sequence Alignment
- Sheep