Genetic polymorphism of glutathion S-transferase P1 (GSTP1) Ile105Val and susceptibility to atherogenesis in patients with type 2 diabetes mellitus

Abstract

One of the characteristics of type 2 diabetes mellitus (T2DM) is the state of persistent oxidative stress (OS) that has been implicated in the pathogenesis of diseases such is atherosclerosis mainly through chronic hyperglycemia that stimulates production of reactive oxygen species (ROS) and increases OS. Glutathione S-transferase P1 (GSTP1) is a member of the cytosolic GST superfamily. It plays an important role in neutralizing OS as an enzyme. Also, it participates in regulation of stress signaling and protects cells against apoptosis via its noncatalytic ligand-binding activity. GSTP1 Ile105Val functional polymorphism influences protein catalytic activity and stability and the aim of this study was to determine whether this gene variation influences susceptibility to atherogenesis in T2DM patients. A total of 240 individuals (140 patients with T2DM, accompanied with clinical manifestations of atherosclerosis, and 100 healthy controls) were included in this study. Genomic DNA was isolated from peripheral blood cells and genotyping was performed using polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) analysis. We obtained no statistically significant differences in the distribution of alleles and genotypes between cases and controls (P>0.05) but association between Ile/Val (OR=0.6, 95%CI=0.35-1.05, P=0.08) and Val/Val (OR=0.45, 95%CI=0.18-1.11, P=0.08) genotypes and disease approached significance (P=0.08). Our results indicated that a larger study group is needed to establish the true relationship between potentialiy protective allele Val and the disease, and to determine the influence of other GSTP1 polymorphisms on atherogenesis in T2DM patients.