RESUMO
ABSTRACT Objective Type 1 diabetes mellitus (T1DM) is an autoimmune disorder caused by a complex interaction between environmental and genetic risk factors. BTB domain and CNC homolog 2 (BACH2) gene encodes a transcription factor that acts on the differentiation and formation of B and T lymphocytes. BACH2 is also involved in the suppression of apoptosis and inflammation in pancreatic beta-cells, indicating a role for it in the development of T1DM. Therefore, the aim of this study was to evaluate the association of the BACH2 rs11755527 single nucleotide polymorphism (SNP) with T1DM. Subjects and methods This case-control study comprised 475 patients with T1DM and 598 nondiabetic individuals. The BACH2 rs11755527 (C/G) SNP was genotyped using real-time PCR with TaqMan MGB probes. Results Genotype distributions of rs11755527 SNP were in accordance with frequencies predicted by the Hardy-Weinberg equilibrium in case and control groups and were similar between groups (P = 0.729). The minor allele frequency was 43.6% in cases and 42.5% in controls (P = 0.604). Moreover, the G allele frequency did not differ between groups when considering different inheritance models and adjusting for age, gender, body mass index, and HLA DR/DQ genotypes of high-risk for T1DM. Although, well-known high-risk T1DM HLA DR/DQ genotypes were associated with T1DM in our population [OR= 7.42 (95% CI 3.34 - 17.0)], this association was not influenced by the rs11755527 SNP. Conclusion The BACH2 rs11755527 SNP seems not to be associated with T1DM in a Brazilian population.
Assuntos
Humanos , Masculino , Feminino , Adulto , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único/genética , Diabetes Mellitus Tipo 1/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Brasil , Estudos de Casos e Controles , Reação em Cadeia da Polimerase , Fatores de Risco , Frequência do Gene , Genótipo , Pessoa de Meia-IdadeRESUMO
It is well established that genetic factors play an important role in the development of both type 2 diabetes mellitus (DM2) and obesity, and that genetically susceptible subjects can develop these metabolic diseases after being exposed to environmental risk factors. Therefore, great efforts have been made to identify genes associated with DM2 and/or obesity. Uncoupling protein 1 (UCP1) is mainly expressed in brown adipose tissue, and acts in thermogenesis, regulation of energy expenditure, and protection against oxidative stress. All these mechanisms are associated with the pathogenesis of DM2 and obesity. Hence, UCP1 is a candidate gene for the development of these disorders. Indeed, several studies have reported that polymorphisms -3826A/G, -1766A/G and -112A/C in the promoter region, Ala64Thr in exon 2 and Met299Leu in exon 5 of UCP1 gene are possibly associated with obesity and/or DM2. However, results are still controversial in different populations. Thus, the aim of this study was to review the role of UCP1 in the development of these metabolic diseases.
Está bem estabelecido que fatores genéticos têm papel importante no desenvolvimento do diabetes melito tipo 2 (DM2) e obesidade e que indivíduos suscetíveis geneticamente podem desenvolver essas doenças metabólicas após exposição a fatores de risco ambientais. Assim, grandes esforços têm sido feitos para a identificação de genes associados ao DM2 e/ou à obesidade. A proteína desacopladora 1 (UCP1) é principalmente expressa no tecido adiposo marrom e atua na termogênese, regulação do gasto energético e proteção contra o estresse oxidativo, mecanismos associados tanto à patogênese do DM2 como à obesidade. Portanto, UCP1 é um gene candidato para o desenvolvimento dessas doenças. De fato, diversos estudos relataram que os polimorfismos -3826A/G, -1766A/G e -112A/C na região promotora, Ala64Thr no éxon 2 e Met299Leu no éxon 5 do gene UCP1 estão possivelmente associados à obesidade e/ou ao DM2. Entretanto, os resultados são ainda controversos em diferentes populações. Então, o objetivo deste estudo foi revisar o papel da UCP1 no desenvolvimento dessas doenças metabólicas.
Assuntos
Humanos , /genética , Canais Iônicos/fisiologia , Proteínas Mitocondriais/fisiologia , Obesidade/genética , Predisposição Genética para Doença , Canais Iônicos/genética , Proteínas Mitocondriais/genética , Polimorfismo GenéticoRESUMO
The increased prevalence of diabetes mellitus has caused a rise in the occurrence of its chronic complications, such as diabetic nephropathy (DN), which is associated with elevated morbidity and mortality. Familial aggregation studies have demonstrated that besides the known environmental risk factors, DN has a major genetic component. Therefore, it is necessary to identify genes associated with risk for or protection against DN. Ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) is expressed in several tissues, including the kidneys. Increased levels of ENPP1 expression inhibit tyrosine-kinase activity of the insulin receptor in several cell types, leading to insulin resistance. K121Q polymorphism of the ENPP1 gene seems to be associated with insulin resistance and DN development. The elucidation of genetic factors and their associations will provide better understanding of the pathogenesis of DN and, may consequently, lead to a more effective approach to prevention and treatment.
A crescente prevalência do diabetes melito tem causado aumento na ocorrência das suas complicações crônicas, como a nefropatia diabética (ND), a qual está associada com elevada morbidade e mortalidade. Estudos de agregação familiar demonstram que a ND tem um importante componente genético, além dos conhecidos fatores de risco ambientais. Portanto, existe a necessidade de se identificarem genes associados ao risco ou proteção à ND. A ectonucleotide pyrophosphatase/phosphodiesterase 1(ENPP1) é expressa em vários tecidos, incluindo nos rins. Foi encontrado que níveis aumentados de expressão da ENPP1 inibem a atividade tirosino-quinase do receptor da insulina em vários tipos celulares, causando resistência à insulina. O polimorfismo K121Q do gene ENNP1parece estar associado com resistência à insulina e com o desenvolvimento da ND. A elucidação dos fatores genéticos e de suas associações permitirá um melhor entendimento da patogênese da ND e, consequentemente, poderemos ter uma abordagem mais efetiva em sua prevenção e tratamento.
Assuntos
Humanos , /enzimologia , Nefropatias Diabéticas/enzimologia , Resistência à Insulina/genética , Diester Fosfórico Hidrolases/genética , Polimorfismo Genético/genética , Pirofosfatases/genética , /genética , Nefropatias Diabéticas/genética , Marcadores Genéticos , Predisposição Genética para DoençaRESUMO
It is well established that genetic factors play an important role in the development of type 2 diabetes mellitus (DM2) and its chronic complications, and that genetically susceptible subjects can develop the disease after being exposed to environmental risk factors. Therefore, great efforts have been made to identify genes associated with DM2. Uncoupling protein 2 (UCP2) is expressed in several tissues, and acts in the protection against oxidative stress; in the negative regulation of insulin secretion by beta cells, and in fatty acid metabolism. All these mechanisms are associated with DM2 pathogenesis and its chronic complications. Therefore, UCP2 is a candidate gene for the development of these disorders. Indeed, several studies have reported that three common polymorphisms in UCP2 gene are possibly associated with DM2 and/or obesity. Only a few studies investigated these polymorphisms in relation to chronic complications of diabetes, with inconclusive results.
Está bem estabelecido que fatores genéticos têm papel importante no desenvolvimento do diabetes melito tipo 2 (DM2) bem como de suas complicações crônicas e que indivíduos geneticamente suscetíveis podem desenvolver essa doença após exposição a fatores de risco ambientais. Assim, grandes esforços têm sido feitos para a identificação de genes associados ao DM2. A proteína desacopladora 2 (UCP2) é expressa em diversos tecidos e atua na proteção contra o estresse oxidativo, na regulação negativa da secreção de insulina pelas células-beta e no metabolismo dos ácidos graxos, mecanismos associados tanto à patogênese do DM2 como a suas complicações crônicas. Portanto, o gene UCP2 é um gene candidato para o desenvolvimento dessas doenças. De fato, diversos estudos têm relatado que três polimorfismos comuns no gene UCP2 estão possivelmente associados ao DM2 e/ou à obesidade. Apenas poucos estudos investigaram esses polimorfismos em relação às complicações crônicas do diabetes, obtendo resultados pouco conclusivos.
Assuntos
Humanos , /genética , Canais Iônicos/genética , Proteínas Mitocondriais/genética , Polimorfismo Genético , /complicações , Doenças Mitocondriais/metabolismoRESUMO
There have been numerous studies genetically characterizing Old World Primates using microsatellites. However, few studies have been made of New World species and none on free-ranging Cebus apella, even though it is probably the most widely distributed species of monkey in the New World. The paucity of studies is due, in part, to the lack of polymorphisms described for this species. We studied two groups of wild tufted capuchins, Cebus apella nigritus, which inhabit Mata Santa Teresa, the Ecological Reserve of Ribeirão Preto, a 158-ha forest fragment in a semi-urban zone of Ribeirão Preto, SP, Brazil. Group 1 had about 60 animals, 35 of which were sampled, and group 2 had about 40 animals, 20 of which were sampled. These group sizes are much larger than the published reports of 6-30 for this species, despite, or perhaps due to the isolation and the size of the forest fragment. Allele PEPC59*1 was the most frequent of all alleles at all loci in both groups (55.7 and 55%), allele PEPC8*1 was the most common allele in group 2 (46.9%) and PEPC8*4 in group 1 (41.1%), allele PEPC3*2 was the most common in group 1 (35.7%) and allele PEPC3*4 in group 2 (31.6%). The genetic diversity, considering each locus in each group, varied from 61.9% at locus PEPC59 to 78.6% at locus PEPC3, both in group 1. The mean genetic diversity (H(S)), considering both groups for all of the loci, was 71.1%. The inter-group diversity (F(ST)) was 1.9%, indicating that these groups belong to the same population. These groups apparently have a high genetic diversity, despite their isolation in a limited forest fragment, although more data are needed to adequately characterize this population.
Assuntos
Animais , Variação Genética , Cebus/genética , Frequência do Gene/genética , Brasil , Genética Populacional , População Urbana , Repetições de Microssatélites/genética , ÁrvoresRESUMO
The polymorphisms and haplotypes identified by restriction fragment length polymorphisms (RFLPs) at the apolipoprotein A1-C3 gene cluster (ApoAl-C3) were studied in 75 Han-nationality-Chinese patients with NIDDM, 30 of which were complicated with hypertriglyceridemia. Fifty unrelated healthy subjects matched for age and body weight were chosen as controls. The results showed that after the RFLPs hydrolyzed by the restriction endonucleases SstI and MspI were hybridized with the human ApoAl gene cDNA fragment(l. 0 kb),S2 and M2 tnutational sites consistent with other reports were found . Significant frequency difference in genotype M1M1 was observed between the simple NIDDM and control group(62% vs 42%). In the NIDDM with hypertriglyceridemia group,both of the S2S2 and M2M2 genotypes had a frequency of 10% and the haplotype S2-M2 had a higher frequency than that in controls. This suggests the association of S2M2 haplotype with NIDDM complicated by hypertriglyceridemia.