Aberrant DNA methylation of M1-macrophage genes in coronary artery disease

Chetan Bakshi,Veena Dhawan,Rajesh Vijayvergiya

doi:10.1038/s41598-018-38040-1

Chetan Bakshi, Veena Dhawan + Show 1 more

Open Access

https://doi.org/10.1038/s41598-018-38040-1

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Abstract

M1 and M2 macrophage balance in atherosclerosis has attracted much interest. Though, it remains unknown how macrophage heterogeneity is regulated. Moreover, the regulation of macrophage polarization and activation also involve DNA methylation. However, it remains ambiguous which genes are under direct regulation by DNA methylation. Our aim was to evaluate the gene-specific promoter DNA methylation status of M1/M2 polarization markers in PBMCs of CAD patients. A case-control study was performed with 25 CAD patients and 25 controls to study the promoter DNA methylation status of STAT1, STAT6, MHC2, IL12b, iNOS, JAK1, JAK2 and SOCS5 using MS-HRM analysis. Our data indicates that there was a clear-cut difference in the pattern of gene-specific promoter DNA methylation of CAD patients in comparison to controls. A significant difference was observed between the percentage methylation of STAT1, IL12b, MHC2, iNOS, JAK1 and JAK2 in CAD patients and control subjects. In conclusion, our data show that MS-HRM assay is a rapid and inexpensive method for qualitatively identifying aberrant gene-specific promoter DNA methylation changes in CAD. Furthermore, we propose that gene-specific promoter DNA methylation based on monocyte/macrophage might aid as diagnostic marker for clinical application or DNA methylation-related drug interventions may offer novel possibilities for atherosclerotic disease management.

Highlights

Coronary artery disease (CAD), a most common cardiovascular disease (CVD), is a foremost cause of mortality globally[1]
Bisulfite treatment of genomic deoxyribonucleic acid (DNA) leads to fragmentation of genomic DNA due to the presence of endonucleases in bisulphite mix, resulting in appearance of smearing pattern when applied on agarose gel
By using the optimized Methylation sensitive-high resolution melting (MS-HRM) assay, we evaluated gene-specific promoter methylation in a total of 50 genomic DNA samples isolated from peripheral blood mononuclear cells (PBMCs) of: a) 25 CAD patients, and b) 25 healthy controls

Summary

Introduction

Coronary artery disease (CAD), a most common cardiovascular disease (CVD), is a foremost cause of mortality globally[1]. Macrophage heterogeneity within atherosclerotic lesions has attracted much interest owing to the importance of balance between M1 and M2 population in determining the plaque outcome and its possible therapeutic implications[10,11] It remains unknown how macrophage heterogeneity is regulated and its contribution in the initiation and propagation of atherosclerosis. DNA methylation is a mechanism which involves the addition of a methyl group to CpG dinucleotide nearby gene promoters, CpG shores and gene bodies, thereby causing transcriptional repression[19,20,21] Both positive and negative correlations between CAD and global DNA methylation of long interspersed nuclear element-1 (LINE-1) and ALU repeats have been reported in the literature[22,23,24,25,26]. Till date, most investigations have primarily focused on post-translational histone modifications and the role of epigenetic mechanisms, DNA methylation needs to be further defined in cardiovascular pathophysiology

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