RESUMO
Ulcerative colitis is a multifactorial disease in which genetic factors play a major role. Functional mutations in the genes related to innate immune response exacerbate mucosal damage coupled with persistent inflammation. The cytokine macrophage migration inhibitory factor (MIF), CD14, and Toll-like receptor 4 (TLR4) are the central players with clearly defined roles in inflammation. The aim of this study was to investigate the association between MIF-173G > C, CD14-159C > T, and TLR4-299A > G polymorphisms and mononuclear cell expression in patients with ulcerative colitis (UC). Genotyping of MIF-173G > C, CD14-159C > T, and TLR4-299A > G polymorphisms was performed by amplification refractory mutation system-polymerase chain reaction and allele-specific amplification in 139 and 176 patients with UC and controls, respectively. Simultaneously, the expression levels of intracellular MIF, mCD14, and mTLR4 were determined in mononuclear cells using a flow cytometer. Polymorphisms in CD14-159C > T and TLR4-299A > G significantly affected mCD14 and mTLR4 expression levels and also increased susceptibility to UC. Although intracellular MIF expression levels differed among patient and control groups, the polymorphism in MIF 173G > C was not observed to be associated with a risk of UC.
Assuntos
Colite Ulcerativa/genética , Regulação da Expressão Gênica , Receptores de Lipopolissacarídeos/genética , Fatores Inibidores da Migração de Macrófagos/genética , Polimorfismo Genético , Receptor 4 Toll-Like/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Citometria de Fluxo , Predisposição Genética para Doença , Genótipo , Humanos , Imunidade Inata/genética , Masculino , Pessoa de Meia-Idade , Receptor 4 Toll-Like/metabolismoRESUMO
OBJECTIVE: The present study was designed to investigate the role of X-ray cross-complementing group 1 (XRCC1) and apurinic/apyrimidinic endonuclease 1 (APE1) polymorphisms in apoptosis and the risk of ulcerative colitis (UC). MATERIALS AND METHODS: Blood samples from 384 unrelated subject (age range 18-65 years; 171 with UC, 213 healthy controls) were collected after colonoscopy. Genomic DNA was isolated and genotyped for XRCC1 Arg399Gln and APE1 Asp148Glu using a confronting two-pair primers polymerase chain reaction. Apoptosis and intracellular reactive oxygen species (ROS) levels in peripheral blood mononuclear cells were measured using annexin-V and H(2)DCFDA assay, respectively. RESULTS: The frequency of genotype Arg399Gln (heterozygous) of XRCC1 gene was significantly higher in patients with UC than the controls (odds ratio [OR] 1.73; 95% confidence interval [CI] 1.13-2.64; p = 0.01). Similarly the genotypic frequency of APE1 Asp148Glu showed statistically significant incidence among UC subjects (OR 1.54; 95% CI 1.02-2.33; p = 0.04). Polymorphism in XRCC1 Arg399Gln and APE1 Asp148Glu together considerably increased the risk of UC (OR 2.303; 95% CI 1.43-3.69; p = 0.0007). ROS levels were high in UC subjects compared with controls (p = 0.01). CONCLUSION: Polymorphisms in XRCC1 Arg399Gln and APE1 Asp148Glu significantly increased the rate of apoptosis and risk of ulcerative colitis.