RESUMO
Inorganic arsenic (iAs) is an important pollutant associated with various chronic-degenerative diseases. The cytoprotective protein nuclear factor erythroid 2-related factor (NRF2) has been proposed as an important responsive mechanism against iAs exposure. The aim of this study was to determine whether the risk of skin lesions in people exposed to iAs-contaminated water could be modified by the presence of single nucleotide polymorphisms in the NRF2 coding gene. We studied 117 individuals with long-term iAs exposure and 120 nonexposed individuals. Total As was determined in water, meanwhile iAs and its metabolites were measured in urine. The iAs-induced skin lesion status was evaluated by expert dermatologists. We sequenced the promoter region of NRF2 in a sample of 120 healthy donors. We found four polymorphisms previously reported and one novel polymorphism in the 5' regulatory region of the NRF2. In this study, we did not find allelic and genotype association of NRF2 polymorphisms with iAs-related skin lesion. However, the analysis of haplotypes composed by -653GA, and -617CA NRF2 single nucleotide polymorphisms showed a significant association with protection against skin lesions in the low-As exposure group. This is the first report studying the association between NRF2 polymorphisms and susceptibility of As-related skin lesions. Increasing the sample size will allow us to confirm this data.
Assuntos
Intoxicação por Arsênico/genética , Arsênio/efeitos adversos , Fator 2 Relacionado a NF-E2/genética , Polimorfismo de Nucleotídeo Único , Dermatopatias/induzido quimicamente , Dermatopatias/genética , Poluentes Químicos da Água/efeitos adversos , Adolescente , Adulto , Intoxicação por Arsênico/diagnóstico , Intoxicação por Arsênico/prevenção & controle , Estudos de Casos e Controles , Estudos Transversais , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Regiões Promotoras Genéticas , Fatores de Proteção , Fatores de Risco , Dermatopatias/diagnóstico , Dermatopatias/prevenção & controle , Adulto JovemRESUMO
Human exposure to arsenicals is associated with inflammatory-related diseases including different kinds of cancer as well as non-cancerous diseases like neuro-degenerative diseases, atherosclerosis, hypertension, and diabetes. Interindividual susceptibility has been mainly addressed by evaluating the role of genetic polymorphism in metabolic enzymes in inorganic arsenic (iAs) metabolism. Glutathione S-transferase omega 1-1 (GSTO1-1), which had been associated with iAs metabolism, is also known to participate in inflammatory and apoptotic cellular responses. The polymorphism A140D of GSTO1-1 has been not only associated with distinct urinary profile of arsenic metabolites in populations chronically exposed to iAs in drinking water, but also with higher risk of childhood leukemia and lung disease in non-exposed populations, suggesting that GSTO1-1 involvement in other physiologic processes different from toxics metabolism could be more relevant than is thought. We evaluated the association of the presence of A140D and E208K polymorphisms of GSTO1-1 gene with the expression of genes codifying for proteins involved in the inflammatory and apoptotic response in a human population chronically exposed to iAs through drinking water. A140D polymorphism was associated with higher expression of genes codifying for IL-8 and Apaf-1 mainly in heterozygous individuals, while E208K was associated with higher expression of IL-8 and TGF- gene, in both cases, the association was independently of iAs exposure level; however, the exposure to iAs increased slightly but significantly the influence of A140D and E208K polymorphisms on such genes expression. These results suggest an important role of GSTO1-1 in the inflammatory response and the apoptotic process and indicate that A140D and E208K polymorphisms could increase the risk of developing inflammatory and apoptosis-related diseases in As-exposed populations.
Assuntos
Fator Apoptótico 1 Ativador de Proteases/genética , Intoxicação por Arsênico/enzimologia , Arsênio/toxicidade , Glutationa Transferase/genética , Inflamação/genética , Interleucina-8/genética , Polimorfismo Genético/efeitos dos fármacos , Adolescente , Adulto , Apoptose/efeitos dos fármacos , Apoptose/genética , Fator Apoptótico 1 Ativador de Proteases/metabolismo , Arsênio/urina , Criança , Pré-Escolar , Água Potável , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Feminino , Contaminação de Alimentos , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Fator de Crescimento Transformador beta/metabolismo , Adulto JovemRESUMO
Our objective was to evaluate alterations in sperm chromatin structure in men occupationally exposed to a mixture of organophosphorus pesticides (OP) because these alterations have been proposed to compromise male fertility and offspring development. Chromatin susceptibility to in situ acid-induced denaturation structure was assessed by the sperm chromatin structure assay (SCSA). Urinary levels of alkylphosphates (DAP) were used to assess exposure. Diethylthiophosphate (DETP) was the most frequent OP metabolite found in urine samples indicating that compounds derived from thiophosphoric acid were mainly used. Chromatin structure was altered in most samples. About 75% of semen samples were classified as having poor fertility potential (>30% of Percentage of DNA Fragmentation Index [DFI%]), whereas individuals without OP occupational exposure showed average DFI% values of 9.9%. Most parameters of conventional semen analysis were within normality except for the presence of immature cells (IGC) in which 82% of the samples were above reference values. There were significant direct associations between urinary DETP concentrations and mean DFI and SD-DFI but marginally (P = 0.079) with DFI%, after adjustment for potential confounders, including IGC. This suggests that OP exposure alters sperm chromatin condensation, which could be reflected in an increased number of cells with greater susceptibility to DNA denaturation. This study showed that human sperm chromatin is a sensitive target to OP exposure and may contribute to adverse reproductive outcomes. Further studies on the relevance of protein phosphorylation as a possible mechanism by which OP alter sperm chromatin are required.