Apolipoprotein E4 allele and ribosomal genes in Alzheimer's disease.

Ribosomal genes are involved in cellular transcription, translation and gene expression modulation process. An association between 28S/18S rRNA ratio levels with apoptosis and aging has been reported. Moulder et al. [22] and Hashimoto et al. [8] showed an association between apolipoprotein E4 allele and neuronal cell apoptosis through diverse mechanisms. The apoE 4 allele is considered a late-onset Alzheimer's disease (AD) risk factor associated with AD pathogenesis. We evaluated the association between apoE4 allele genotyping by PCR and rRNA 28S/18S ratio by slot blotting technique using peripheral blood samples of 18 Alzheimer's disease patients, 18 elderly controls and 18 young controls. A rRNA ratio decrease was observed in AD individuals confirming our previous results but this association is independently of the ApoE4 allele genotype. Thus our results pointed that two different mechanisms are involved in the etiology of Alzheimer disease each one leading independently to cell death. Further studies could investigate these factors.

APO A-V-1131T-->C polymorphism frequency and its association with morbidity in a Brazilian elderly population.

Identification of genetic polymorphisms as risk factors for complex diseases affecting older people can be relevant for their prevention, diagnosis and management. The -1131T-->C polymorphism of the apolipoprotein A-V gene (APO A-V) is tightly linked to lipid metabolism and has been associated with increased triglyceride levels and familial dyslipidemia. The aims of this study were to analyze the allele and genotype frequencies of this polymorphism in a Brazilian elderly population and to investigate any association between the polymorphism and major morbidities affecting elderly people. This polymorphism was investigated in 371 individuals, aged 66-97 years, in a Brazilian Elderly Longitudinal Population Study. Major morbidities investigated were: cerebrovascular diseases (CVD); myocardial infarction (MI); type 2 diabetes; hypertension; obesity; dementia; depression; and neoplasia. DNA was isolated and amplified by PCR and its products were digested with restriction enzyme Tru1I. T and C allele frequencies were 0.842 and 0.158, respectively. Our population showed allele frequencies that were similar to European and Afro-American and different from Asiatic populations. Genotype distributions were not within Hardy-Weinberg equilibrium only for the obesity subject sample. On the other hand, a significant association between the C allele and obesity in the presence of CVDxdepression interaction was observed. Logistic analysis showed no association of the polymorphism with each morbidity group. Therefore, the C allele in elderly Brazilian subjects may represent a risk factor for these morbidity interactions, which may lead to better comprehension of their pathophysiology.