Description

Different promoter methylation status of atherosclerosis-related genes in individual cell types of peripheral leukocytes

Jeeyeon Kim, Junha Hwang, Jong Wook Shin, Jei Kim

Neuroepigenetics Laboratory, Department of Neurology, School of Medicine and Hospital Chungnam National University, Daejeon, South Korea

Introduction: In atherosclerosis tissues, variable cell types (T-cells, B-cells, macrophage, and endothelial progenitor cells [EPC]) of peripheral leukocytes are infiltrated. The individual cells have different roles for the development of atherosclerosis. However, epigenetic changes of the individual cell types have not been well known. The present study evaluated whether the individual leukocytes has similar promoter methylation status in atherosclerosis-related genes, or not.

Methods: We, first, sorted peripheral leukocytes using CD19 for B-cells, CD3 for T-cells, and CD34 antibody for EPC (MicroBead Kit, Miltenyi Biotec) from buffy coat of one man and one woman.Then, promoter methylation status of atherosclerosis-related genes (ALOX12, NETO1, and, AIRE1) of CD19+, CD3+, CD34+ cells, and, non-sorted total peripheral leukocytes was evaluated using pyrosequencing. Finally, differences of the promoter methylation status were compared between total and individual cell types (B- and T-cell, and EPC)

Results: Of the three genes, promoter methylation of ALOX12 (CD19+, 45.9; CD3+, 62.2; CD34+, 46.9, Total, 35.7%, p=0.23) was significantly higher in CD3+ cells than others. Promoter methylation of NETO1 (CD19+, 28.1; CD3+, 19.0; CD34+, 67.0, Total, 8.12%, p<0.01) was higher in CD34+ cells than others. However, AIRE1 (CD19+, 65.3; CD3+, 70.1; CD34+, 70.7, Total, 67.6%) showed similar promoter methylation in all 4 cell types. Conclusion: The present study showed individual promoter methylation differences by specific genes and by cell types of peripheral leukocytes. Recently, peripheral leukocytes have been recommended as a useful tissue to evaluate atherosclerosis related epigenetic alterations. However, the present study provide rationale to be cautious when we choose peripheral leukocytes and specific genes to study epigenetic alterations related with atherosclerosis.