RESUMO
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
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.
Assuntos
Envelhecimento/genética , DNA Mitocondrial/genética , Longevidade/genética , Idoso , Idoso de 80 Anos ou mais , Análise Mutacional de DNA , DNA Mitocondrial/química , Feminino , Haplótipos/genética , Humanos , Masculino , Mutação , Mutação de Sentido Incorreto , Análise de Sequência de DNARESUMO
RATIONALE: Recent studies have found decreased serotonin (5-HT) transmission within the nucleus accumbens following withdrawal from chronic cocaine. OBJECTIVE: We sought to investigate whether increasing brain 5-HT levels would decrease behavioral responses that occur following cocaine withdrawal, namely increased preference for a cocaine environment and anxiety. METHODS: The conditioned place preference and the defensive burying paradigms were used to measure the behavioral responses that occur 1 week following cocaine withdrawal. RESULTS: We show that pharmacological agents that increase 5-HT transmission (sertraline or 5-hydoxytryptophan, 5-HTP) abolish the preference of subchronically cocaine-treated, abstinent rats for a cocaine-associated environment. Similar results were seen when sertraline was microinjected into the nucleus accumbens. Conversely, rats acutely conditioned with cocaine showed an increased preference for a cocaine-associated environment when pretreated with these drugs. Sertraline also decreased the heightened anxiety-like behaviors found in subchronically treated cocaine rats. CONCLUSIONS: These results indicate that drugs that augment 5-HT function may reduce the desire for cocaine following cocaine withdrawal, and thus facilitate cocaine abstinence in dependent subjects.
