Lower Methylation of the ANGPTL2 Gene in Leukocytes from Post-Acute Coronary Syndrome Patients

PLoS One. 2016 Apr 21;11(4):e0153920. doi: 10.1371/journal.pone.0153920. eCollection 2016.

Abstract

DNA methylation is believed to regulate gene expression during adulthood in response to the constant changes in environment. The methylome is therefore proposed to be a biomarker of health through age. ANGPTL2 is a circulating pro-inflammatory protein that increases with age and prematurely in patients with coronary artery diseases; integrating the methylation pattern of the promoter may help differentiate age- vs. disease-related change in its expression. We believe that in a pro-inflammatory environment, ANGPTL2 is differentially methylated, regulating ANGPTL2 expression. To test this hypothesis we investigated the changes in promoter methylation of ANGPTL2 gene in leukocytes from patients suffering from post-acute coronary syndrome (ACS). DNA was extracted from circulating leukocytes of post-ACS patients with cardiovascular risk factors and from healthy young and age-matched controls. Methylation sites (CpGs) found in the ANGPTL2 gene were targeted for specific DNA methylation quantification. The functionality of ANGPTL2 methylation was assessed by an in vitro luciferase assay. In post-ACS patients, C-reactive protein and ANGPTL2 circulating levels increased significantly when compared to healthy controls. Decreased methylation of specific CpGs were found in the promoter of ANGPTL2 and allowed to discriminate age vs. disease associated methylation. In vitro DNA methylation of specific CpG lead to inhibition of ANGPTL2 promoter activity. Reduced leukocyte DNA methylation in the promoter region of ANGPTL2 is associated with the pro-inflammatory environment that characterizes patients with post-ACS differently from age-matched healthy controls. Methylation of different CpGs in ANGPTL2 gene may prove to be a reliable biomarker of coronary disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Coronary Syndrome / genetics*
  • Angiopoietin-Like Protein 2
  • Angiopoietin-like Proteins
  • Angiopoietins / genetics*
  • Biomarkers / metabolism
  • Case-Control Studies
  • DNA Methylation*
  • Female
  • Humans
  • Leukocytes / metabolism*
  • Male
  • Middle Aged

Substances

  • ANGPTL2 protein, human
  • Angiopoietin-Like Protein 2
  • Angiopoietin-like Proteins
  • Angiopoietins
  • Biomarkers

Grants and funding

The work was funded by the Canadian Institute for Health Research (ET). Students were supported through fellowship (VT) and scholarship (SL) of the Canadian Institute for Health Research. GL holds a Canada Research Chair. Clinical research (JL, MG, DH, MJ, A Nigam) and basic research (ET, NTT) teams are supported by an annual grant of the Foundation of the Montreal Heart Institute. Clinical research in prevention is supported by the EPIC Foundation, the prevention center of the Montreal Heart Institute.