Methylation status of CpG sites in the MCP-1 promoter is correlated to serum MCP-1 in Type 2 diabetes.

AIM: Monocyte chemoattractant protein-1 (MCP-1) is a potent chemokine and plays an important role in atherosclerosis of Type 2 diabetes. The aim of this study was to investigate the methylation status of CpG sites in the MCP-1 promoter in Type 2 diabetic patients and its correlation to serum MCP- 1 level, and blood glucose level.

METHODS: The 32 patients with Type 2 diabetes and 15 healthy controls were enrolled into the study. Bodymass index, blood pressure, blood lipid, blood glucose, glycosylated hemoglobin (HbA1c), and serum MCP-1 were measured. Genomic DNA was isolated fromthe peripheral blood mononuclear cells (PBMC). Methylation status of CpG sites in theMCP-1 promoter was determined using methylation specific polymerase chain reaction.

RESULTS: The promoter region (2890-3050 bp) was predominantly methylated in PBMC from controls.Methylation of CpGmotifs were less methylated in the patients than in the controls (25% vs 80%; p<0.001), while the level of MCP-1 in serum was higher in patients with Type 2 diabetes (193.95±74.96 vs 88.46±55.10; p<0.001). MCP-1 promoter methylation was significantly correlated to serum MCP-1, HbA1c, fasting blood glucose, and triglyceride.

CONCLUSION: These data suggest that hypomethylation of CpG sites in the MCP-1 promoter region may be affected by blood glucose and TG, which then increase the serum MCP-1 level and may play a role in the vascular complications of Type 2 diabetes.