RESUMO
BACKGROUND: Polycystic ovary syndrome (PCOS) is a complex endocrine disorder that involves multiple factors. Although the etiology of PCOS is unknown, there is an involvement of sex steroid hormones in the pathophysiology of this syndrome. Therefore, polymorphisms in genes involved in the action of estrogen may contribute to a woman's susceptibility to PCOS. AIM: This study aimed to evaluate the association between the polymorphisms PvuII and XbaI in the estrogen receptor alpha (ESR1) gene and the occurrence of PCOS. The study also aimed to assess the influence of these polymorphisms on the metabolic and inflammatory profiles of women with PCOS. MATERIAL AND METHODS: This case-control study included 99 women with PCOS, diagnosed according to the Rotterdam criteria, and 104 age-matched healthy women. The polymorphisms were evaluated using polymerase chain reaction-restriction fragment length polymorphism. RESULTS: No association between the ESR1 gene polymorphisms and the presence of PCOS was observed. However, we found associations between the PvuII polymorphism and C-reactive protein levels, testosterone levels, family history of diabetes, and waist circumference. The XbaI polymorphism was associated with fasting glucose and a family history of hypertension. CONCLUSION: These polymorphisms are not associated with PCOS development, but they are involved in the phenotype of complications of the syndrome. Therefore, prior knowledge of these genomic variants might contribute to taking preventive measures that could delay the metabolic and reproductive complications commonly seen in women with PCOS.
Assuntos
Receptor alfa de Estrogênio/genética , Síndrome do Ovário Policístico/genética , Polimorfismo de Fragmento de Restrição , Adulto , Glicemia/genética , Glicemia/metabolismo , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , DNA-Citosina Metilases/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Mediadores da Inflamação/metabolismo , Resistência à Insulina/genética , Pessoa de Meia-Idade , Síndrome do Ovário Policístico/imunologia , Síndrome do Ovário Policístico/metabolismo , Adulto JovemRESUMO
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.
Assuntos
DNA-Citosina Metilases/genética , Glutationa S-Transferase pi/genética , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/genética , Praguicidas/toxicidade , Polimorfismo Genético/genética , DNA Metiltransferases Sítio Específica (Adenina-Específica)/genética , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Frequência do Gene , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Fatores de Risco , Fatores SexuaisRESUMO
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. .
Assuntos
Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , DNA-Citosina Metilases/genética , Glutationa S-Transferase pi/genética , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/genética , Praguicidas/toxicidade , Polimorfismo Genético/genética , DNA Metiltransferases Sítio Específica (Adenina-Específica)/genética , Estudos de Casos e Controles , Frequência do Gene , Heterozigoto , Reação em Cadeia da Polimerase , Fatores de Risco , Fatores SexuaisRESUMO
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.
Assuntos
Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Insuficiência Ovariana Primária/genética , Adulto , Brasil , DNA-Citosina Metilases/genética , Estrogênios/genética , Feminino , Genótipo , Haplótipos , Humanos , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Fatores de RiscoRESUMO
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.
Assuntos
DNA-Citosina Metilases/genética , Miócitos de Músculo Liso/enzimologia , Neoplasias/genética , Animais , Linhagem Celular Tumoral , Cromatina/metabolismo , Ilhas de CpG/genética , Metilação de DNA , DNA-Citosina Metilases/metabolismo , Regulação para Baixo , Genes Supressores de Tumor , Camundongos , Camundongos Transgênicos , Miócitos de Músculo Liso/metabolismo , Neoplasias/enzimologia , Tamanho do ÓrgãoRESUMO
Epigenetic alterations such as DNA methylation have been implicated in the development and progression of various cancers. DNA methylation consists of the reversible addition of a methyl group to the carbon 5 position of cytosine in CpG dinucleotides and is considered essential for normal embryonic development. However, global genomic hypomethylation and aberrant hypermethylation of regulatory regions of tumor suppressor genes have been associated with chromosomal instability and transcription repression, respectively, providing neoplastic cells with a selective advantage. DNA methyltransferases are the enzymes responsible for the addition of methyl groups to CpG dinucleotides, which, together with histone modifiers, initiate the events necessary for transcription repression to occur. It has been demonstrated that increased expression of DNA methyltransferases may contribute to tumor progression through methylation-mediated gene inactivation in various human cancers. Given their importance, this article reviews the main epigenetic mechanisms for regulating transcription and its implications in cancer development.
Assuntos
DNA-Citosina Metilases/metabolismo , Epigênese Genética , Neoplasias/genética , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/antagonistas & inibidores , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA , DNA Metiltransferase 3A , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , HumanosRESUMO
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.
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Metilação de DNA , Proteínas de Drosophila/genética , Drosophila/genética , Genoma , Sequência de Aminoácidos , Animais , Southern Blotting , Mapeamento Cromossômico , DNA/genética , DNA-Citosina Metilases/genética , Drosophila/citologia , Feminino , Masculino , Dados de Sequência Molecular , Análise de Sequência de DNARESUMO
BACKGROUND: Determination of the diversity within the tet(M) sequence from N gonorrhoeae is a useful epidemiologic tool for monitoring the movement or importation of strains within a geographic region. Only two distinct tet(M) genes in clinical gonococcal isolates have been described up to now: the Dutch and the American types. GOAL: The study involved surveillance of the tet(M) gene types in high-level-tetracycline-resistant gonococcal isolates from Uruguay during the period 1996 to 1999. STUDY DESIGN: Among 181 gonococcal isolates, those showing MICs >/=16 microg/ml to tetracycline were analyzed for detection and characterization of the tet(M) gene by a polymerase chain reaction (PCR) and further HpaII restriction fragment polymorphism methods, respectively. The plasmid content and antibiogram were determined. RESULTS: Twenty-two of 181 isolates (12%) exhibited high levels of resistance to tetracycline (MICs >/=16 microg/ml) and harbored a putative 25.2-Mda plasmid that contained the tet(M) gene. A high percentage of isolates (95%; 21/22) presented the Dutch type tet(M) gene. One isolate from 1999 revealed a new restriction pattern. Such a pattern had been previously noted in 1991. This new restriction pattern has not been described previously as occurring in isolates of N gonorrhoeae. The tet(M) amplimer sequence showed 100% identity with a previously described tet(M)-carrying plasmid from N meningitidis. CONCLUSION: A new HpaII restriction pattern of the tet(M) gene is present in low frequency. The tet(M) sequence was different from the gonococcal tet(M) sequences already known and not typable with the use of a differential PCR assay. Accordingly, with the genetic diversity already present within the tet(M) sequence of N gonorrhoeae isolates, we should be aware of the sensitivity of the PCR assays in use for tetracycline-resistant N gonorrhoeae detection.
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Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana , Gonorreia/epidemiologia , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/genética , Tetraciclina/farmacologia , Antibacterianos/uso terapêutico , Sequência de Bases , DNA-Citosina Metilases , Gonorreia/tratamento farmacológico , Gonorreia/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Vigilância da População/métodos , Tetraciclina/uso terapêutico , Uruguai/epidemiologiaRESUMO
Increased amounts of chromatin condensation (i.e., localized areas of high DNA density, or chromatin higher order packing state) have been described in NIH 3T3 cells transformed with the Ha-ras oncogene. The structural basis for this oncogene-mediated alteration in nuclear organization is unknown. Since DNA methylation is likely to be involved in regulating the nucleosomal level of DNA packaging, we studied the role of DNA methylation in higher-order chromatin organization induced by Ha-ras. CpG-methylated DNA content was estimated in "condensed" chromatin of Ha-ras-transformed NIH 3T3 cell lines which differ in ras expression and ras-induced metastatic ability but present approximately the same values of "condensed" chromatin areas. The question posed was that if DNA methylation were involved with the chromatin higher-order organization induced by Ha-ras in these cell lines, the methylated DNA density in the "condensed" chromatin would also be the same. The DNA evaluation was performed by video image analysis in Feulgen-stained cells previously subjected to treatment with Msp I and Hpa II restriction enzymes, which distinguish between methylated and non-methylated DNA. The amount of methylated CpG sequences not digested by Hpa II in "condensed" chromatin regions was found to vary in the studied ras-transformed cell lines. DNA CpG methylation status is thus suggested not to be involved with the higher order chromatin condensation induced by ras transformation in the mentioned NIH 3T3 cell lines.
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Cromatina/química , Metilação de DNA , DNA/metabolismo , Genes ras , Corantes de Rosanilina , Células 3T3 , Animais , Linhagem Celular Transformada , Cromatina/genética , Corantes , DNA-Citosina Metilases , Desoxirribonuclease HpaII , Processamento de Imagem Assistida por Computador , Camundongos , Microscopia de VídeoRESUMO
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.