Association of Paraoxonase-2 (C1053G) Gene Polymorphism with the Expression of Paraoxonase-2 Gene in Patients of Ischemic Stroke - A Pilot Study in Indian Population

Background and Objective: Oxidative stress plays an important role in atherosclerosis and ischemic stroke. Due to antioxidant properties of Paraoxonase-2, we studied the implication of Paraoxonase-2 gene polymorphism (C1053G) on expression of Paraoxonase-2 gene at mRNA level in ischemic stroke patients. Material and Methods: 40 patients of ischemic stroke and 40 age and sex-matched controls were included. Paraoxonase-2 genotypes were evaluated by Polymerase Chain Reaction and Restriction Fragment Length Polymorphism and expression of Paraoxonase-2 gene at mRNA level was determined by quantitative real time Polymerase Chain Reaction analysed as delta-CT (Delta CT). Result and Discussion: The observed allele frequencies in patients for C and G allele were 0.61 and 0.39 respectively, and were 0.72 and 0.28 in control group. No significant association was found in C allele of C1053G polymorphism and ischemic stroke. The average Delta CT value is significantly (p = 0.0001) higher in patients group (7.68 +/- 2.0) as compared to controls (5.70 +/- 1.8). We found a significant difference in the average delta-CT value (p = 0.0001), wherein down-regulated paraoxonase-2 gene expression (approximately 0.25 fold) was observed in case of patients as compared to controls. Down-regulated expression of paraoxonase-2 gene was observed in patients with GG genotype as compared to CG and CC genotypes in patients with ischemic stroke (p = 0.0001). Conclusion: Down-regulated Paraoxonase-2 gene expression, as evidenced by low mRNA levels in GG genotype may be one of the contributory factors in the progression of ischemic stroke.