RESUMO
Deregulated microRNA (miR)/transcription factor (TF)-based networks represent a hallmark of cancer. We report here a novel c-Myc/miR-23b/Sp1 feed-forward loop with a critical role in multiple myeloma (MM) and Waldenstrom's macroglobulinemia (WM) cell growth and survival. We have found miR-23b to be downregulated in MM and WM cells especially in the presence of components of the tumor bone marrow milieu. Promoter methylation is one mechanism of miR-23b suppression in myeloma. In gain-of-function studies using miR-23b mimics-transfected or in miR-23b-stably expressing MM and WM cell lines, we observed a significant decrease in cell proliferation and survival, along with induction of caspase-3/7 activity over time, thus supporting a tumor suppressor role for miR-23b. At the molecular level, miR-23b targeted Sp1 3'UTR and significantly reduced Sp1-driven nuclear factor-κB activity. Finally, c-Myc, an important oncogenic transcription factor known to stimulate MM cell proliferation, transcriptionally repressed miR-23b. Thus MYC-dependent miR-23b repression in myeloma cells may promote activation of oncogenic Sp1-mediated signaling, representing the first feed-forward loop with critical growth and survival role in myeloma.
Assuntos
Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , MicroRNAs/genética , Mieloma Múltiplo/genética , Proteínas Proto-Oncogênicas c-myc/genética , Fator de Transcrição Sp1/genética , Animais , Sequência de Bases , Sítios de Ligação , Caspase 3/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular/genética , Metilação de DNA , Modelos Animais de Doenças , Regulação para Baixo , Expressão Gênica , Perfilação da Expressão Gênica , Inativação Gênica , Genes Reporter , Humanos , MicroRNAs/química , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-myc/química , Proteínas Proto-Oncogênicas c-myc/metabolismo , Interferência de RNA , RNA Mensageiro/química , RNA Mensageiro/genética , Fator de Transcrição Sp1/química , Fator de Transcrição Sp1/metabolismoRESUMO
This review summarizes the results of the activities which have taken place in 2014 within the Standard Model Working Group of the "What Next" Workshop organized by INFN, Italy. We present a framework, general questions, and some indications of possible answers on the main issue for Standard Model physics in the LHC era and in view of possible future accelerators.
RESUMO
Preservation of functional ability is a well-recognized marker of longevity. At a molecular level, a major determinant of the physiological decline occurring with aging is the imbalance between production and accumulation of oxidative damage to macromolecules, together with a decreased efficiency of stress response to avoid or repair such damage. In this paper we investigated the association of 38 genes (311 SNPs) belonging to the pro-antioxidant pathways with physical and cognitive performances, by analyzing single SNP and gene-based associations with Hand Grip strength (HG), Activities of Daily Living (ADL), Walking Speed (WS), Mini Mental State Examination (MMSE) and Composite Cognitive Score (CCS) in a Cohort of 1089 Danish nonagenarians. Moreover, for each gene analyzed in the pro-antioxidant pathway, we tested the influence on longitudinal survival. In the whole sample, nominal associations were found for TXNRD1 variability with ADL and WS, NDUFS1 and UCP3 with HG and WS, GCLC and UCP2 with WS (p<0.05). Stronger associations although not holding the multiple comparison correction, were observed between MMSE and NDUFV1, MT1A and GSTP1 variability (p<0.009). Moreover, we found that association between genetic variability in the pro-antioxidant pathway and functional status at old age is influenced by sex. In particular, most significant associations were observed in nonagenarian females, between HG scores and GLRX and UCP3 variability, between ADL levels and TXNRD1, MMSE and MT1A genetic variability. In males, a borderline statistically significant association with ADL level was found for UQCRFS1 gene. Nominally significant associations in relation to survival were found in the female sample only with SOD2, NDUFS1, UCP3 and TXNRD1 variability, the latter two confirming previous observations reported in the same cohort. Overall, our work supports the evidence that genes belonging to the pro-anti-oxidant pathway are able to modulate physical and cognitive performance after the ninth decade of life, finally influencing extreme survival.
Assuntos
Atividades Cotidianas , Estresse Oxidativo , Polimorfismo de Nucleotídeo Único , Idoso , Idoso de 80 Anos ou mais , Cognição , Feminino , Humanos , MasculinoRESUMO
In a scenario of increasing life expectancy worldwide, it is mandatory to identify the characteristics of a healthy aging phenotype, including survival predictors, and to disentangle those related to environment/lifestyle versus those related to familiarity/genetics. To this aim we comprehensively characterised a cohort of 1,160 Italian subjects of 90 years and over (90+, mean age 93 years; age range 90-106 years) followed for 6 years survival, belonging to 552 sib-ships (familiar longevity) recruited (2005-2008) within the EU-funded GEHA project in three Italian geographic areas (Northern, Central and Southern Italy) different for urban/rural and socio-economical characteristics. On the whole, the following factors emerged as significant predictors of survival after 90 years of age: absence of cognitive impairment and physical disability, high hand grip strength scores and body mass index (BMI) values, "excellent/good" self-reported health, high haemoglobin and total cholesterol levels and low creatinine levels. These parameters, excluding BMI values, were also significantly associated within sib-ships, suggesting a strong familial/genetic component. Geographical micro-heterogeneity of survival predictors emerged, such as functional and physical status being more important in Southern than in Central and Northern Italy. In conclusion, we identified modifiable survival predictors related to specific domains, whose role and importance vary according to the geographic area considered and which can help in interpreting the genetic results obtained by the GEHA project, whose major aim is the comprehensive evaluation of phenotypic and genetic data.
Assuntos
Atividades Cotidianas , Envelhecimento/genética , Nível de Saúde , Longevidade/genética , Idoso de 80 Anos ou mais , Bases de Dados Factuais , Europa (Continente)/epidemiologia , Feminino , Seguimentos , Humanos , Itália/epidemiologia , Masculino , Fenótipo , Estudos Retrospectivos , Taxa de Sobrevida/tendênciasRESUMO
In 2004, the integrated European project GEHA (Genetics of Healthy Ageing) was initiated with the aim of identifying genes involved in healthy ageing and longevity. The first step in the project was the recruitment of more than 2500 pairs of siblings aged 90 years or more together with one younger control person from 15 areas in 11 European countries through a coordinated and standardised effort. A biological sample, preferably a blood sample, was collected from each participant, and basic physical and cognitive measures were obtained together with information about health, life style, and family composition. From 2004 to 2008 a total of 2535 families comprising 5319 nonagenarian siblings were identified and included in the project. In addition, 2548 younger control persons aged 50-75 years were recruited. A total of 2249 complete trios with blood samples from at least two old siblings and the younger control were formed and are available for genetic analyses (e.g. linkage studies and genome-wide association studies). Mortality follow-up improves the possibility of identifying families with the most extreme longevity phenotypes. With a mean follow-up time of 3.7 years the number of families with all participating siblings aged 95 years or more has increased by a factor of 5 to 750 families compared to when interviews were conducted. Thus, the GEHA project represents a unique source in the search for genes related to healthy ageing and longevity.
Assuntos
Envelhecimento/genética , Longevidade/genética , Seleção de Pacientes , Projetos de Pesquisa , Idoso , Idoso de 80 Anos ou mais , Cognição , Europa (Continente)/epidemiologia , Família , Feminino , Ligação Genética , Estudo de Associação Genômica Ampla , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Inquéritos e QuestionáriosRESUMO
BACKGROUND AND PURPOSE: Mitochondrial DNA (mtDNA) inherited variability (haplogroup/sub-haplogroup) is currently emerging as not being neutral with respect to several complex traits like neurodegenerative diseases. Here we investigated the association of European mtDNA haplogroups/sub-haplogroups with frontotemporal dementia (FTD). METHOD AND RESULTS: A case-control study was carried out on 114 patients with FTD (68 sporadic and 46 familial) and 180 controls, matched for age, gender and ethnicity. No association was found. CONCLUSIONS: European mtDNA haplogroups/sub-haplogroups are unlikely to play a major role in the risk of developing the disease.
Assuntos
DNA Mitocondrial/genética , Demência/genética , Haplótipos/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , DNA Mitocondrial/classificação , Demência/epidemiologia , Etnicidade/genética , Feminino , Predisposição Genética para Doença , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-IdadeRESUMO
The variability of the Succinic Semialdehyde Dehydrogenase (SSADH, or ALDH5A1) gene affects both pathological and normal phenotypes correlated to cognitive function. We tested the association between the C538T polymorphism of the SSADH gene and preservation of cognitive function in the elderly, and its possible effects on survival. A sample from southern Italy (514 subjects; 18-107 years) was screened for C538T variability. We found that, within the 65-85 years age range, the T/T genotype is overrepresented in subjects with impaired cognitive function (MMSE < or = 23) compared to those with conserved cognitive function (MMSE > 23). Furthermore, we found that the T/T genotype affects survival after 65 years of age. In fact, after this age, the survival function of T/T homozygous subjects is lower than that of the others. Given that the enzymatic activity of the protein encoded by allele T is 82.5% of the activity of the protein encoded by allele C, our results suggest that the efficiency of the SSADH enzyme is important for the preservation of cognitive function and survival in the elderly.
Assuntos
Envelhecimento/genética , Envelhecimento/psicologia , Cognição/fisiologia , Polimorfismo de Nucleotídeo Único , Succinato-Semialdeído Desidrogenase/genética , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/metabolismo , Sequência de Bases , Transtornos Cognitivos/enzimologia , Transtornos Cognitivos/genética , Primers do DNA/genética , Feminino , Frequência do Gene , Genótipo , Humanos , Itália/epidemiologia , Masculino , Succinato-Semialdeído Desidrogenase/fisiologia , Análise de SobrevidaRESUMO
Starting from the observation that human longevity patterns show regional variations, we applied Spatial Analysis (using the Geographic Information System) and Surname Analysis to highlight the effect of the population genetic structure on such patterns. The study was carried out in Calabria, a southern Italian region which is characterized by a wide variability of geographic features (high mountains and deep valleys which created geographic isolates in the past). We identified three zones of high longevity: a male and a female longevity zone were located near the town of Cosenza (northern Calabria), while a male longevity zone was located in a mountainous and quite isolated part of the province of Reggio Calabria (southern Calabria). The latter zone was characterized by the lowest Female/Male ratio in nonagenarians observed to date. By applying surname analysis (Fisher's alpha) we found a significant negative correlation between surname abundance and index of longevity, showing that this isolated zone of male longevity presents a high level of inbreeding. On the whole, the results showed the effectiveness of spatial analysis in revealing geographical longevity patterns, and highlighted the importance of the population genetic structure in shaping such patterns.
Assuntos
Demografia , Genética Populacional , Endogamia , Longevidade/genética , Nomes , Idoso de 80 Anos ou mais , Feminino , Sistemas de Informação Geográfica , Geografia , Humanos , Itália , MasculinoRESUMO
The definition of a precise and consistent aging phenotype that allows to measure the physical and cognitive decline, as well as the increase of mortality hazard late in life, is a major problem for studies aimed at finding the genetic factors modulating rate and quality of human aging. In this frame, it seems promising the concept of frailty which tends to figure out the subjects who are more vulnerable and more prone to negative outcomes, such as death or hospitalization. Cognitive, functional and psychological measures turned out to be the most effective measures to define frailty, as they condense most of the frailty cycle that occurs in the elderly and is probably responsible of the aging related physical decline. We used MMSE, Hand Grip strength, and GDS as variable parameters in a hierarchical Cluster Analysis (CA) in order to recognise aging phenotypes. By using a sample of 65-85 years old subjects we identified three frailty phenotypes that were consistent from both geriatric and genetic perspectives. Therefore, the method we propose may provide unbiased phenotypes suitable for the identification of genetic variants affecting the quality of aging in this age range. The CA method was less effective in ultranonagenarians, probably due to the high prevalence of frail subjects in this age group that makes difficult to distinguish discrete phenotypes.
Assuntos
Envelhecimento/genética , Análise por Conglomerados , Avaliação Geriátrica/métodos , Fenótipo , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Cognição/fisiologia , Depressão/fisiopatologia , Feminino , Força da Mão/fisiologia , Humanos , Masculino , Entrevista Psiquiátrica Padronizada , Reprodutibilidade dos TestesRESUMO
The human SIRT3 gene contains an intronic VNTR enhancer whose variability is correlated with life span. The SIRT3 5' flanking region encompasses the PSMD13 gene encoding the p40.5 regulator subunit of the 26S proteasome. Proteasome is a multicatalytic proteinase whose function declines with aging. SIRT3 and PSMD13 are linked in a head-to-head configuration (788-bp intergenic region). The molecular configuration of two genes that are both related to aging prompted us to search for shared regulatory mechanisms between them. Transfection experiments carried out in HeLa cells by deletion mutants of the PSMD13-SIRT3 intergenic region showed a complex pathway of coregulation acting in both directions. Furthermore, linkage disequilibrium (LD) analyses carried out in a sample of 710 subjects (18-108 years of age) screened for A21631G (marker of PSMD13), and for G477T and VNTR(intron5) (markers of SIRT3), revealed high LD, with significantly different PSMD13-SIRT3 haplotype pools between samples of centenarians and younger people.
Assuntos
Envelhecimento/genética , Proteínas Mitocondriais/genética , Regiões Promotoras Genéticas , Complexo de Endopeptidases do Proteassoma/genética , Sirtuínas/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Bases , Mapeamento Cromossômico , DNA/genética , DNA Intergênico , Feminino , Genes Reporter , Genética Populacional , Haplótipos , Células HeLa , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Repetições Minissatélites , Dados de Sequência Molecular , Deleção de Sequência , Sirtuína 3RESUMO
Frontotemporal dementia (FTD) is a complex dementing syndrome whose genetic/non genetic risk factors are mostly unknown. Aim of the present work was to investigate whether APOE and/or tau gene variability does affect the risk of FTD. A sample of FTD cases (sporadic: n = 54; familial: n = 46, one subject per family) was collected in a genetically homogeneous population (Calabria, southern Italy) and analyzed in comparison with an age- and sex-matched control group (n = 180) extracted from the same population. Logistic regression analysis showed that APOE gene variability affects the probability of disease, with allele epsilon4 increasing (exp(beta1) = 2.68 with [1.51-4.76] 95% confidence interval; p = 0.001) and allele epsilon2 decreasing (exp(beta1) = 0.28 with [0.12-0.66] 95% confidence interval; p = 0.003) the risk of FTD. On the contrary, tau gene variability was ineffectual (exp(beta1) non significantly different from 1 for either H1 or H2 haplotypes), although a small effect was observed by the H1 haplotype in increasing the protective effect of the epsilon2 allele (p = 0.007).
Assuntos
Apolipoproteínas E/genética , Demência/genética , Proteínas tau/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/patologia , DNA/genética , Análise Mutacional de DNA , Demência/patologia , Demência/psicologia , Feminino , Variação Genética , Haplótipos , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , RiscoRESUMO
The human sirtuin 3 (SIRT3) gene encodes a putative mitochondrial NAD-dependent deacetylase (SIRT3) which belongs to the evolutionary conserved family of sirtuin 2 proteins. Studies in model organisms have demonstrated that SIR2 genes control lifespan, while no data are available regarding a possible role of SIRT3 in human longevity. By analysing the genotype-specific survival function relevant to the G477T marker of SIRT3, we found that in males the TT genotype increases (p=0.0272), while the GT genotype decreases (p=0.0391) survival in the elderly. Since SIRT3 lies in a chromosomal region (11p15.5) where four genes potentially associated with longevity are located (HRAS1, Insulin-like Growth Factor 2, Proinsulin, and Tyrosine Hydroxylase) we tested for linkage-disequilibrium between G477T alleles and alleles of the above genes. The disequilibrium was not significant in any case, thus suggesting that SIRT3 itself, or a gene strictly linked to SIRT3, may have a role in human longevity.
Assuntos
Histona Desacetilases/genética , Longevidade/genética , Proteínas Mitocondriais/genética , Sirtuínas/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cromossomos Humanos Par 11/genética , Feminino , Genótipo , Haplótipos , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Polimorfismo de Fragmento de Restrição , Sirtuína 3 , Taxa de SobrevidaRESUMO
Heat shock proteins (HSPs) are crucial for maintenance of cell homeostasis and survival both during and after various stresses. The capability to cope with stress is believed to affect the chance of health and survival at organismal level. We have investigated whether the gene pool relevant to the (A/C)(-110) polymorphism in the promoter region of the HSP70-1 gene changes as the population ages and survival selection occurs. A total of 591 southern Italian subjects were enrolled in the study (263 males and 328 females; age range 18-109 years), free of clinically manifest diseases and with normal haemato-chemical parameters. A significant age-related decrease of the frequency of allele (A)(-110) was observed in females. The probability ratio of 0.403 (95% confidence interval [0.163, 0.910]) computed by considering female centenarians as cases and young women (18-49 years old) as controls showed that the (A)(-110) allele is unfavorable to longevity in females.
Assuntos
Alelos , Proteínas de Choque Térmico HSP70/genética , Longevidade/genética , Regiões Promotoras Genéticas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo GenéticoRESUMO
Analyses of mtDNA and Y-chromosome variation were performed in a sample of Iraqis, a scarcely investigated population of the "Fertile Crescent." A total of 216 mtDNAs were screened for the diagnostic RFLP markers of the main Eurasian and African haplogroups. A subset of these samples, whose HVS-I sequences were previously obtained, was also examined by high-resolution restriction analysis. The Y-chromosome variation was investigated in 139 subjects by using 17 biallelic markers and the 49a,f/Taq I system. For both uniparental systems, the large majority of the haplogroups observed in the Iraqi population are those (H, J, T, and U for the mtDNA, and J(xM172) and J-M172 for the Y chromosome) considered to have originated in the Middle East and to have later spread all over Western Eurasia. However, about 9% of the mtDNAs and 30% of the Y-chromosomes most likely represent arrivals from distant geographic regions. The different proportion of long-range genetic input observed for the mtDNA and the Y chromosome appears to indicate that events of gene flow to this area might have involved mainly males rather than females.
Assuntos
Cromossomos Humanos Y/genética , DNA Mitocondrial/genética , Filogenia , Polimorfismo Genético , Geografia , Haplótipos/genética , Humanos , Iraque , Masculino , Polimorfismo de Fragmento de Restrição , Dinâmica Populacional , Análise de Componente PrincipalRESUMO
An informative set of biallelic polymorphisms was used to study the structure of Y-chromosome variability in a sample from the Mediterranean islands of Corsica and Sicily, and compared with data on Sardinia to gain insights into the ethnogenesis of these island populations. The results were interpreted in a broader Mediterranean context by including in the analysis neighboring populations previously studied with the same methodology. All samples studied were enclosed in the comparable spectrum of European Y-chromosome variability. Pronounced differences were observed between the islands as well as in the percentages of haplotypes previously shown to have distinctive patterns of continental phylogeography. Approximately 60% of the Sicilian haplotypes are also prevalent in Southern Italy and Greece. Conversely, the Corsican sample had elevated levels of alternative haplotypes common in Northern Italy. Sardinia showed a haplotype ratio similar to that observed in Corsica, but with a remarkable difference in the presence of a lineage defined by marker M26, which approaches 35% in Sardinia but seems absent in Corsica. Although geographically adjacent, the data suggest different colonization histories and a minimal amount of recent gene flow between them. Our results identify possible ancestral continental sources of the various island populations and underscore the influence of founder effect and genetic drift. The Y-chromosome data are consistent with comparable mtDNA data at the RFLP haplogroup level of resolution, as well as linguistic and historic knowledge.
Assuntos
Cromossomos Humanos Y/genética , Genética Populacional , Haplótipos , Filogenia , França , Humanos , Itália , Masculino , Ilhas do Mediterrâneo , SicíliaRESUMO
All the demographic surveys on the centenarians have highlighted that females outnumber males. The centenarians' male/female (M/F) ratio reported by most studies ranges between 1:4 and 1:7. A puzzling 1:2 ratio was observed in Calabria, a Southern Italian region. To our knowledge only in Sardinia a similar phenomenon had been previously observed. We have therefore used the data of the Italian Institute of Statistics to figure out the centenarians' M/F ratio in the Italian regions. We found that this ratio gradually decreases from South to North. Such a result is certainly due to many factors. Thus, we have explored the possibility, it is also influenced by the genetic structure of the Italian population. In fact, the distribution of the centenarians' M/F ratio turned out to be significantly correlated with the genetic structure of the Italian population as outlined by the principal component analysis.
Assuntos
Longevidade/genética , Idoso , Idoso de 80 Anos ou mais , Humanos , Itália/epidemiologia , Dinâmica Populacional , Vigilância da População , Razão de MasculinidadeRESUMO
The impressive performance of the research in mitochondrial genetics and human aging in the last decade outlines a new scenery in which the inherited variation of the mitochondrial genome (mtDNA) may play a role in rate and quality of aging. This variation in humans was initially looked at as nearly neutral, and useful just for the reconstruction of human population history. However, recent data suggest that different mtDNA molecules are qualitatively different from each other. The aim of this paper is to discuss current ideas on the relationships among mitochondrial function, mtDNA inherited variation, and aging. The main processes where the mitochondrion is involved and the importance these processes have on aging and death of individuals will be described. A possible connection between programmed death phenomena (mitoptosis, apoptosis, phenoptosis) and rate and quality of aging will be discussed. Finally, the possible role played in these processes by the mtDNA germline variation will be explored.
Assuntos
Envelhecimento/fisiologia , DNA Mitocondrial/genética , Mitocôndrias/genética , Apoptose/fisiologia , DNA Mitocondrial/classificação , Variação Genética , Humanos , Mitocôndrias/metabolismo , Modelos Biológicos , Fosforilação Oxidativa , FilogeniaRESUMO
The identification of a growing number of novel Mendelian disorders and private mutations in the Roma (Gypsies) points to their unique genetic heritage. Linguistic evidence suggests that they are of diverse Indian origins. Their social structure within Europe resembles that of the jatis of India, where the endogamous group, often defined by profession, is the primary unit. Genetic studies have reported dramatic differences in the frequencies of mutations and neutral polymorphisms in different Romani populations. However, these studies have not resolved ambiguities regarding the origins and relatedness of Romani populations. In this study, we examine the genetic structure of 14 well-defined Romani populations. Y-chromosome and mtDNA markers of different mutability were analyzed in a total of 275 individuals. Asian Y-chromosome haplogroup VI-68, defined by a mutation at the M82 locus, was present in all 14 populations and accounted for 44.8% of Romani Y chromosomes. Asian mtDNA-haplogroup M was also identified in all Romani populations and accounted for 26.5% of female lineages in the sample. Limited diversity within these two haplogroups, measured by the variation at eight short-tandem-repeat loci for the Y chromosome, and sequencing of the HVS1 for the mtDNA are consistent with a small group of founders splitting from a single ethnic population in the Indian subcontinent. Principal-components analysis and analysis of molecular variance indicate that genetic structure in extant endogamous Romani populations has been shaped by genetic drift and differential admixture and correlates with the migrational history of the Roma in Europe. By contrast, social organization and professional group divisions appear to be the product of a more recent restitution of the caste system of India.
Assuntos
DNA Mitocondrial/genética , Haplótipos/genética , Roma (Grupo Étnico)/genética , Cromossomo Y/genética , Emigração e Imigração , Europa (Continente) , Feminino , Frequência do Gene/genética , Variação Genética/genética , Humanos , Índia/etnologia , Masculino , Mutação/genética , Filogenia , Polimorfismo Genético/genética , Tamanho da AmostraRESUMO
We have analyzed a sample of 40 centenarians and 116 young controls from Sardinia, with a set of new Y chromosome binary markers, to evaluate if Y chromosome genes are involved in the high prevalence of males among centenarian Sardinians (1/2 vs. 1/4 in other populations studied). The results indicate that none of the seven lineages that account for >97% of the Y chromosome diversity in Sardinia provide an advantage with respect to the extreme longevity. However, our results, although based on the male-specific Y chromosome polymorphisms, give a clear profile of the pattern of genetic variability in Sardinia. Indeed they indicate that the Sardinian population had two main founder populations that have evolved in isolation for at least the last 5,000 years. These findings set the stage for future studies on longevity and other complex traits in Sardinia.
Assuntos
Envelhecimento , Marcadores Genéticos , Cromossomo Y , Idoso , Idoso de 80 Anos ou mais , Haplótipos , Humanos , Itália , Desequilíbrio de Ligação , Masculino , Filogenia , Polimorfismo GenéticoRESUMO
Previous studies have shown that mitochondrial DNA (mtDNA) haplogroup J is significantly over-represented in healthy centenarians with respect to younger controls, thus suggesting that this haplogroup predisposes to successful aging and longevity. On the other hand, the same haplogroup is reported to have elevated frequency in some complex diseases. To verify if centenarians clustered in a particular lineage within J we have sequenced the D-loop region from 18 centenarians and 18 younger controls, previously characterized to be J. Then the entire mtDNA molecule was sequenced in a sub-sample of nine centenarians to find possible functional mutations associated with haplogroup J in successful aging. No clustering of the J haplogroup mtDNA from centenarians was observed. In addition, most of the mutations found are known as disease-associated mutations. The general picture that emerges from the study is that the J haplogroup of centenarians is surprisingly similar to that found in complex diseases, as well as in Leber Hereditary Optic Neuropathy. This finding implies that the same mutations could predispose to disease or longevity, probably according to individual-specific genetic backgrounds and stochastic events. This data reveals another paradox of centenarians and confirms the complexity of the longevity trait.