Exposure to pesticides and heterozygote genotype of GSTP1-Alw26I are associated to Parkinson's disease.

OBJECTIVE: This study aimed to analyze the frequency of GSTP1-Alw26I polymorphism and to estimate its association with toxic substances in Parkinson's disease (PD). METHODS: A study group with 154 patients - subdivided into familial and sporadic PD groups - and 158 elderly individuals without the disease (control group) were evaluated. GSTP1-Alw26I polymorphism was analyzed by polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP). RESULTS: Patients were significantly more exposed to pesticides compared with the control group (p=0.0004), and the heterozygote genotype associated to exposure to pesticides also prevailed in patients (p=0.0001). Wild homozygote genotype was related to tobacco use (p=0.043) and alcoholism (p=0.033) in familial PD patients. CONCLUSION: Exposure to pesticides is associated to PD, whose effect can be enhanced when combined with the heterozygote genotype of GSTP1-Alw26I. Also, large genetic and environmental studies considering tobacco use, alcoholism, GSTP1 and PD are necessary to confirm our findings.

Exposure to pesticides and heterozygote genotype of GSTP1-Alw26I are associated to Parkinson's disease / Exposição a pesticidas e genótipo heterozigoto de GSTP1-Alw26I associam-se à doença de Parkinson

Objective This study aimed to analyze the frequency of GSTP1-Alw26I polymorphism and to estimate its association with toxic substances in Parkinson's disease (PD). Methods A study group with 154 patients - subdivided into familial and sporadic PD groups - and 158 elderly individuals without the disease (control group) were evaluated. GSTP1-Alw26I polymorphism was analyzed by polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP). Results Patients were significantly more exposed to pesticides compared with the control group (p=0.0004), and the heterozygote genotype associated to exposure to pesticides also prevailed in patients (p=0.0001). Wild homozygote genotype was related to tobacco use (p=0.043) and alcoholism (p=0.033) in familial PD patients. Conclusion Exposure to pesticides is associated to PD, whose effect can be enhanced when combined with the heterozygote genotype of GSTP1-Alw26I. Also, large genetic and environmental studies considering tobacco use, alcoholism, GSTP1 and PD are necessary to confirm our findings. .

Objetivo Analisar a frequência do polimorfismo GSTP1-Alw26I, assim como estimar sua associação com substâncias tóxicas na doença de Parkinson (DP). Métodos A casuística avaliada foi composta por um grupo de estudo, com 154 pacientes, subdivididos em DP familial e esporádica, e outro com 158 idosos sem a doença (grupo controle). O polimorfismo GSTP1-Alw26I foi analisado por reação em cadeia da polimerase/polimorfismo de comprimento do fragmento de restrição (PCR/RFLP). Resultados Os pacientes foram significativamente mais expostos a pesticidas, comparados com o grupo controle (p=0,0004), e o genótipo heterozigoto associado a exposição a pesticidas também prevaleceu nos pacientes (p=0,0001). O genótipo homozigoto selvagem apresentou relação com tabagismo (p=0,043) e etilismo (p=0,033) em pacientes com DP familial. Desse modo, a exposição a pesticidas está associada à DP, cujo efeito pode ser potencializado quando combinado ao genótipo heterozigoto de GSTP1-Alw26I. Estudos genético-ambientais envolvendo tabagismo, etilismo, GSTP1 e DP devem ser realizados em casuísticas numerosas, confirmando essa associação. .

Risk of premature ovarian failure is associated to the PvuII polymorphism at estrogen receptor gene ESR1.

PURPOSE: Estrogen plays an important role in the human reproductive system and it action is mediated mainly by two specific receptors: α (ERα) and ß (ERß). There were described polymorphic variants in ESR1 and ESR2 genes and studies showed controversial results regarding their association with premature ovarian failure. We aimed to determine the prevalence of ESR1 and ESR2 polymorphisms in Brazilian patients and controls. After associate the polymorphisms with premature ovarian failure (POF). METHODS: Genetic association study was performed with 70 women with POF and 73 normally menopaused controls. Detection of ESR1 (PvuII/and XbaI) and ESR2 (AluI and RsaI) gene polymorphisms were performed using TaqMan PCR. The single-nucleotide polymorphism (SNPs) and haplotype effects were analyzed by multivariate logistic regression and haplotype analysis and a p-value < 0.05 was considered significant. RESULTS: Individual SNP analysis revealed that PvuII polymorphism was statistically associated with POF (p = 0.034) under a recessive model. Regarding XbaI, AluI and RsaI SNPs, no statistical difference was observed between POF group and controls (p = 0.575, p = 0.258 and p = 0.483, respectively). Combined genotypes of ESR1 and ESR2 polymorphisms did not identify a risk haplotype associated with POF. CONCLUSION: In Brazilian population evaluated results have demonstrated that the genetic variation in ESR1 gene (PvuII polymorphism) is associated to POF risk.

Organomegaly and tumors in transgenic mice with targeted expression of HpaII methyltransferase in smooth muscle cells.

Current data suggest that angiogenesis, smooth muscle cell migration, differentiation and proliferation may be epigenetically regulated. Prokaryotic DNA methyltransferases have been proposed as tools to modify mammalian DNA methylation. In order to assess the impact of DNA hypermethylation on smooth muscle pathophysiology, we expressed an HpaII site-specific methyltransferase transgene in smooth muscle cells in mice. The enzyme is expected to target only a subset (CCGG) of unmethylated CpG dinucleotides, thus avoiding possible deleterious effects of widespread hypermethylation. Transgenics of two independent lines were born at expected frequencies, showed no obvious abnormalities and were fertile. Nevertheless, ~30% of > 1 year-old transgenics developed organomegaly and ~20% showed a range of tumors. Global DNA methylation was unchanged in transgenic tissue whether hyperplastic or normal, but tumor DNA showed a pronounced global hypermethylation. DNA hypermethylation was not indiscriminate, as five tested tumor suppressor genes showed promoter CpG and non-CpG hypermethylation and transcriptional down-regulation, whereas the methylation status of one intergenic CpG islands, repeated elements (n=2) and non-tumor suppressor gene promoters (n=3) was unchanged. Our work is the first report on the effects of HpaII methyltransferase on endogenous chromatin and in a whole animal. Furthermore, our data expand previous findings that imply that global DNA hypomethylation is not an obligate oncogenic pathway at least in the tumor types examined here.

First evidence of methylation in the genome of Drosophila willistoni.

DNA methylation has been studied abundantly in vertebrates and recent evidence confirms that this phenomenon could be disseminated among some invertebrates groups, including Drosophila species. In this paper, we used the Methylation-Sensitive Restriction Endonuclease (MSRE) technique and Southern blot with specific probes, to detect methylation in the Drosophila willistoni species. We found differential cleavage patterns between males and females that cannot be explained by Mendelian inheritance, pointing to a DNA methylation phenomenon different from the Drosophila melanogaster one. The sequencing of some of these bands showed that these fragments were formed by different DNA elements, among which rDNA. We also characterized the D. willitoni dDnmt2 sequence, through a Mega Blast search against the D. willistoni Trace Archive Database using the D. melanogaster dDnmt2 nucleotide sequence as query. The complete analysis of D. willistoni dDnmt2 sequence showed that its promoter region is larger, its dDnmt2 nucleotide sequence is 33% divergent from the D. melanogaster one, Inverted Terminal Repeats (ITRs) are absent and only the B isoform of the enzyme is produced. In contrast, ORF2 is more conserved. Comparing the D. willistoni and D. melanogaster dDnmt2 protein sequences, we found higher conservation in motifs from the large domain, responsible for the catalysis of methyl transfer, and great variability in the region that carries out the recognition of specific DNA sequences (TRD). Globally, our results reveal that methylation of the D. willistoni genome could be involved in a singular process of species-specific dosage compensation and that the DNA methylation in the Drosophila genus can have diverse functions. This could be related to the evolutionary history of each species and also to the acquisition time of the dDnmt2 gene.

Nucleotide sequence of the gene encoding the BstLVI DNA methyltransferase: comparison with other amino-DNA methyltransferases.

The nucleotide sequence of a 2837-base pairs (bp) EcoRI-PvuI fragment of Bacillus stearothermophilus LV chromosomal DNA encoding the bstLVIM gene was determined. It revealed a large open reading frame (ORF) of 1737 bp specifying a methylase of 579 amino acid (aa) residues and Mr 66,831. This was in agreement with the size estimated for the M. BstLVI ( approximately 67 kDa) purified from Escherichia coli cells harboring a recombinant plasmid containing the bstLVIM gene and with results of transcription-translation experiments performed in vitro. Upstream the bstLVIM gene and in the opposite transcriptional orientation, there is a 81-aa ORF that showed great homology with the regulatory C proteins identified in other type II restriction and modification (R-M) systems. This 81-aa ORF precedes a truncated ORF of 86 aa which in turn may represent the structural gene for the BstLVI restriction endonuclease.