Promoter methylation of SREBP-2 in circulating leukocytes correlates with relevant risk factors in patients with coronary artery disease

Objective To examine the correlation between the promoter methylation of Sterol regulatory-element binding protein-2 (SREBP-2) and miR-33a expression as well as serum markers in patients with coronary artery disease (CAD). Methods The case-control study. 100 participants who underwent coronary angiography from August 2017 to April 2018 in TaiheHospital, Hubei University of Medicine, were recruited in this study.The methylation level of two fragments, including 12 CpG sites in the promoter region of SREBP-2, have been detected by pyrosequencing in 50 patients with coronary artery disease (CAD) and 50 non-CAD controls. Serum miR-33a level and a panel of 15 CAD related biomarkers were examined by qPCR and routine biochemistry methods. Results Methylation level of one CpG site (F1-4 loci) in SREBP-2 promoter region were significant higher in CAD patients than in controls(4.56%±0.70% vs 3.54%±0.72%, t=-3.864, P<0.001); methylation level of F1-4 site was negatively correlates with the serum miR-33a levels and high-density lipoprotein cholesterol (HDL-C) levels(r=-0.318, P=0.001; r=-0.225, P=0.024, respectively). Furthermore, F1-4 hypermethylation was an independent risk factor of CAD, independent of age, gender, histories of hypertension, hyperlipidemia, and diabetes(OR=2.452, 95%CI=1.398-4.299, P=0.002). Conclusion These results suggest that DNA methylation and miRNA might cooperate to regulate the lipid metabolism in CAD. Key words: Coronary disease; Sterol regulatory element binding protein 2; DNA methylation; microRNAs; Lipid metabolism disorders