Roger Willian de Labio

Promoter methylation analysis of SIRT3, SMARCA5, HTERT and CDH1 genes in aging and Alzheimer's disease.

Longevity related genes were investigated concerning promoter methylation. SIRT3, SMARCA5, HTERT and CDH1 promoters were analyzed in peripheral blood in relation to gender, age and Alzheimers disease (AD). Methylation Specific PCR assay (MSP) was used. There were no significant differences in methylation frequencies of SIRT3, SMARCA5 and CDH1 among young, elderly and AD groups (p> 0.05), showing no association with aging or AD. On the other hand, HTERT methylation frequency was associated with the aging process, in that AD patients differed from elderly controls (p=0.0086), probably due to telomere and immune dysfunctions involved in AD pathogenesis.

SORL1 and SIRT1 mRNA expression and promoter methylation levels in aging and Alzheimer’s Disease

Alzheimers Disease (AD) is a neurodegenerative disorder and the most common cause of dementia among the elderly. Efforts have been made to understand the genetic and epigenetic mechanisms involved in the development of this disease. As SORL1 (sortilin-related receptor) and SIRT1 (sirtuin 1) genes have been linked to AD pathogenesis, we aimed to investigate their mRNA expression and promoter DNA methylation in post mortem brain tissues (entorhinal and auditory cortices and hippocampus) from healthy elderly subjects and AD patients. We also evaluated these levels in peripheral blood leukocytes from young, healthy elderly and AD patients, investigating whether there was an effect of age on these profiles. The comparative CT method by Real Time PCR and MALDI-TOF mass spectrometry were used to analyze gene expression and DNA methylation, respectively. SORL1 gene was differently expressed in the peripheral blood leukocytes and might act as a marker of aging in this tissue. Furthermore, we found that SORL1 promoter DNA methylation might act as one of the mechanisms responsible for the differences in expression observed between blood and brain for both healthy elderly and AD patients groups. The impact of these studied genes on AD pathogenesis remains to be better clarified.

Analysis of HSPA8 and HSPA9 mRNA Expression and Promoter Methylation in the Brain and Blood of Alzheimer's Disease Patients

Alzheimers disease (AD) is the most common form of dementia in elderly. Chaperones may have a crucial role in AD due to their involvement in protein quality control, folding, and degradation. In this study, we investigated the mRNA and promoter DNA methylation levels of two chaperones, HSPA8 and HSPA9, in postmortem brain tissue (entorhinal and auditory cortices and hippocampus) from healthy elderly and AD subjects as well as in peripheral blood of healthy elderly and AD patients. mRNA quantification was performed by qRT-PCR and DNA methylation by mass spectrometry. In the peripheral blood, we did not observe a significant difference in HSPA8 and HSPA9 expression between elderly controls and AD. A significant downregulation of HSPA8 and HSPA9 was observed in AD across the three brain regions compared to the controls, suggesting their participation in AD pathogenesis. However, no important DNA methylation differences were observed, suggesting that other mechanism may be involved in controlling these genes expression.

Werner helicase polymorphism is not associated with Alzheimer's disease

Alzheimer disease (AD) is the most common neurodegenerative disorder in the elderly and is also considered a progeroid genetic syndrome. The etiology of AD is complex and the mechanisms underlying its pathophysiology remains to be clarified. Werner syndrome (WS) is a rare autosomal recessive disorder characterized as a segmental progeroid syndrome. The gene (WRN) was recently identified. Its product acts as a DNA helicase and exonuclease. This study investigates the association of AD with the WRN 1367 polymorphisms in samples of 67 DA patients, 56 elderly healthy and 66 young healthy controls. DNA was isolated from blood cells, amplified by PCR and digested with PmaCI. We observed that the genotype distributions of WRN 1367 variants were within Hardy-Weinberg equilibrium in all subject samples. Furthermore, chi-square test comparison for genotype distributions and allele frequencies did not reveal any significant difference among the three groups of subjects (P>0.05). These results support the idea that these variants are not involved as a risk factor for developing AD.

Frequency of Werner helicase 1367 polymorphism and age-related morbidity in an elderly Brazilian population

Werner syndrome (WS) is a premature aging disease caused by a mutation in the WRN gene. The gene was identified in 1996 and its product acts as a DNA helicase and exonuclease. Some specific WRN polymorphic variants were associated with increased risk for cardiovascular diseases. The identification of genetic polymorphisms as risk factors for complex diseases affecting older people can improve their prevention, diagnosis and prognosis. We investigated WRN codon 1367 polymorphism in 383 residents in a district of the city of São Paulo, who were enrolled in an Elderly Brazilian Longitudinal Study. Their mean age was 79.70 +/- 5.32 years, ranging from 67 to 97. This population was composed of 262 females (68.4%) and 121 males (31.6%) of European (89.2%), Japanese (3.3%), Middle Eastern (1.81%), and mixed and/or other origins (5.7%). There are no studies concerning this polymorphism in Brazilian population. These subjects were evaluated clinically every two years. The major health problems and morbidities affecting this cohort were cardiovascular diseases (21.7%), hypertension (83.7%), diabetes (63.3%), obesity (41.23%), dementia (8.0%), depression (20.0%), and neoplasia (10.8%). Their prevalence is similar to some urban elderly Brazilian samples. DNA was isolated from blood cells, amplified by PCR and digested with PmaCI. Allele frequencies were 0.788 for the cysteine and 0.211 for the arginine. Genotype distributions were within that expected for the Hardy-Weinberg equilibrium. Female gender was associated with hypertension and obesity. Logistic regression analysis did not detect significant association between the polymorphism and morbidity. These findings confirm those from Europeans and differ from Japanese population.

Interleukin-8-251T > a, interleukin-1α-889C > t and apolipoprotein e polymorphisms in Alzheimer's disease

An inflammatory process has been involved in numerous neurodegenerative disorders such as Parkinson’s disease, stroke and Alzheimer’s disease (AD). In AD, the inflammatory response is mainly located in the vicinity of amyloid plaques. Cytokines, such as interleukin-8 (IL-8) and interleukin-1α (IL-1α), have been clearly involved in this inflammatory process. Polymorphisms of several interleukin genes have been correlated to the risk of developing AD. The present study investigated the association of AD with polymorphisms IL-8 -251T > A (rs4073) and IL-1α-889C > T (rs1800587) and the interactive effect of both, adjusted by the Apolipoprotein E genotype. 199 blood samples from patients with AD, 146 healthy elderly controls and 95 healthy young controls were obtained. DNA samples were isolated from blood cells, and the PCR-RFLP method was used for genotyping. The genotype distributions of polymorphisms IL-8, IL-1α and APOE were as expected under Hardy-Weinberg equilibrium. The allele frequencies did not differ significantly among the three groups tested. As expected, the APOE4 allele was strongly associated with AD (p < 0.001). No association of AD with either the IL-1α or the IL-8 polymorphism was observed, nor was any interactive effect between both polymorphisms. These results confirm previous studies in other populations, in which polymorphisms IL-8 -251T > A and IL-1α-889C > T were not found to be risk factors for AD.

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

Abstract 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 66–97years, 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 CVD×depression 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.

Interleukin-8 Gene Polymorphism −251T>A and Alzheimer's Disease

Alex Augusto Vendraminia, Roger Willian de Labiob, Lucas Trevisani Rasmussenb, Thais Minettd, Paulo Henrique Ferreira Bertoluccid, Marilia de Arruda Cardoso Smithc and Spencer Luiz Marques Payaoa,b,∗ Mestrado em Biologia Oral, USC Universidade do Sagrado Corac ao, Bauru, Sao Paulo, Brazil Disciplina Genetica, Hemocentro FAMEMA, Faculdade de Medicina de Mar ilia, Marilia, Sao Paulo, Brazil Departamento de Morfologia, UNIFESP/EPM Universidade Federal de S ao Paulo, Escola Paulista de Medicina, Sao Paulo, Brazil Disciplina de Neurologia, UNIFESP/EPM, Sao Paulo, Brazil

Interleukin 8 (-251 T>A) polymorphism in children and teenagers infected with Helicobacter pylori

BackgroundHelicobacter pylori (H. pylori) is a gram-negative bacterium that colonizes the human stomach and causes a variety of gastric diseases. This study evaluated the correlations between the -251 (T>A) (rs4073) polymorphism of interleukin-8 (IL-8), the etiology of gastric disease, and H. pylori infection in pediatric and adolescent patients.MethodsDNA samples were obtained from 285 gastric biopsies from pediatric patients. H. pylori was detected by PCR, whereas PCR-RFLP was used to characterize the -251 (T>A) polymorphism of IL-8.ResultsThe histological analysis revealed the presence of gastritis in 158 patients (55.44%). H. pylori was found in 71 samples (24.9%). The -251 (T>A) polymorphism revealed that 58 (29.47%) samples were TT, 143 (50.18%) samples were TA, and 84 (20.35%) samples were AA.ConclusionsOur findings suggest that IL8-251 A allele may be an important risk factor for the development of gastric disease when associated with H. pylori infection.

Orchidectomy enhances the expression of endothelin-1 and ETB receptors in rat portal vein.

Functional studies have shown that orchidectomy increases the effects of phenylephrine on rat portal veins, but that it is completely prevented in the presence of both ETA and ETB receptor antagonists. Although it suggests the involvement of endothelin-1 (ET-1), the local production of this vasoactive peptide has not been directly quantified in portal veins. Therefore, the aim of the present study was to verify if orchidectomy increases the local expression of ET-1 as well as ETA and ETB receptors in the rat portal vein. Indeed, the genic expression of ET-1, ETA and ETB receptors in rat portal veins taken from control (CONT), orchidectomized (ORX) and ORX plus testosterone-replacement therapy (ORX + T) animals were determined by Real Time RT-PCR. The results showed that orchidectomy induced a significant increment in genic expression of ET-1and ETB receptors in the rat portal veins, which was completely reversed by testosterone replacement treatment. In conclusion, the results suggest that orchidectomy increases the production of ET-1 in the rat portal vein and that, at least partially, it may be related to the previously reported elevation of responses to phenylephrine.