Association of Heat Shock Protein 70 (HSP-70) and Endothelial Nitric Oxide Synthase (eNOS) in the Pathogenesis of Diabetic Retinopathy in Southeast Asian Population

Abstract

Present study was set to investigate the role of genetic polymorphisms of the oxidative and inflammatory pathway genes including Heat Shock Protein 70 (HSP 70) and endothelial Nitric Oxide Synthase (eNOS) in the onset of Diabetic Retinopathy (DR) among the southeast Asian population like Pakistan. A case-control association study was conducted for a total of 553 individuals (among which 160 were DR, 193 DNR while 200 were healthy controls) by screening Single Nucleotide Polymorphisms (SNPs) in HSP70 (promoter region: (-27G>C) through standard Polymerase Chain Reaction (PCR) while the eNOS [exon 7 SNP rs1799983 (c.894G>T; p.Glu298Asp) of eNOS was genotyped through PCR Restriction Fragment Length Polymorphism (PCR-RFLP) and an intron 4 VNTR] promoter regions was screened through standard PCR.For HSP70, a significant association of the C allele was found for diabetic individuals specifically the males (χ² =21.30, p<0.05, OR=2.58 [95% CI=1.68–3.97, p<0.05]) while no association of eNOS (rs1799983 and VNTR) was observed in the studied subject. The current study concluded that HSP70 polymorphism is associated with diabetic retinopathy while, eNOS seemed to have no role in diabetes retinopathy susceptibility in south Asian diabetic patients. Bioinformatic analysis also supported the genetic analysis where lack of association was observed for exonic SNP rs1799983 of eNOS with diabetic retinopathy.