Relationship Between Global DNA Methylation And Hydroxymethylation In Peripheral Blood Of Elderly Patients With Myocardial Infarction And Coronary Atheroslerosis

Background:Coronary atherosclerotic heart disease,or coronary heart disease,is the leading cause of death and disability in developed countries,contributing directly to the pathological basis of myocardial infarction.DNA methylation and hydroxymethylation showed an effect of epigenetic modification which also had close relationships to the coronary diseses.DNA hydroxyl methylation is oxidized to 5-hydroxymethylcytosine(5-hmC)in the presence of Ten-Eleven Translocation-2(TET2).Recent studies have shown a dispute of DNA methylation and hydroxymethylation in atherosclerosis and the level of DNA methylation and methylation of peripheral blood in the peripheral blood of elderly patients with myocardial infarction is not yet reported.Objective:To investigate the relationship between the levels of global DNA methylation and hydroxymethylation in peripheral blood of elderly patients with myocardial infarction and the degree of coronary atherosclerosis.Methods:The 43 elderly patients with myocardial infarction were enrolled as the study group and the 53 elderly patients with negative findings in coronary angiograms during the same period were collected as the control group.Peripheral blood samples were collected.The levels of global DNA methylation and hydroxymethylation in peripheral blood and the concentration of plasma TET2 were detected by enzyme-linked immunosorbent assay.TET2 mRNA expression were determined by RT-qPCR.Results:Compared with the control group,the levels of global DNA methylation and hydroxymethylation in peripheral blood of elderly patients with myocardial infarction were significantly increased(P =0.014;P =0.000).The concentration of plasma TET2 and its mRNA expression in patients with myocardial infarction were significantly higher than those in the control group(P = 0.004;P = 0.028).The levels of global DNA methylation and hydromethylation in myocardial infarction group were significantly correlated with the degree of coronary atherosclerosis(r =0.262,P = 0.017;r = 0.360,P =0.001).There was no significant difference of 5-mC between control and MI group with non-diabetic.But in the MI group with diabetic,5-mC level was significantly higher than that in the control group.Conclusion:The levels of global DNA methylation and hydroxymethylation in peripheral blood of elderly patients with myocardial infarction are significantly increased,which are significantly correlated with the degree of coronary atherosclerosis.