Objective: Our objective was to study the association of the human microRNA-126 (miR-126) gene rs4636297 and rs1140713 polymorphisms and the plasma-circulating miR-126 level in acute myocardial infarction (AMI). Methods: The genotypes of the miR-126 gene rs4636297 and rs1140713 loci were characterized by the direct sequencing method in 350 AMI patients and 350 healthy controls. The level of plasma-circulating miR-126 was measured by reverse transcription real-time polymerase chain reaction. Results: Plasma-free miR-126 levels and Gensini scores (r = -0.684, p < 0.001), serum brain natriuretic peptide (BNP) levels (r = -0.808, p < 0.001), low-density lipoprotein cholesterol (LDL-C) levels (r = -0.769, p < 0.001), and cardiac troponin I (cTnI) levels (r = -0.754, p < 0.001) were negatively correlated. The risk of AMI for rs4636297 locus A allele carriers was significantly lower than G allele carriers (adjusted odds ratio = 0.79, 95% confidence interval (CI) = 0.65-0.93, p = 0.004). The rs1140713 locus T allele carriers were 1.56 times more likely to develop AMI than the C allele carriers (95% CI = 1.35-1.73, p < 0.001). The single nucleotide polymorphisms (SNPs) rs4636297 and rs1140713 of the miR-126 gene were correlated with the Gensini score, serum BNP, LDL-C, cTnI, and serum vascular endothelial growth factor levels in patients with AMI (p < 0.05). Conclusion: The miR-126 gene SNPs rs4636297 and rs1140713 are associated with AMI, possibly by influencing the expression levels of the miR-126 gene.
Keywords: acute myocardial infarction; gene polymorphism; microRNA-126.