Methylation of the estrogen receptor gene is associated with aging and atherosclerosis in the cardiovascular system

Objective: Methylation of the promoter region of the estrogen receptor gene alpha ( ER α ) occurs as a function of age in human colon, and results in inactivation of gene transcription. In this study, we sought to determine whether such age-related methylation occurs in the cardiovascular system, and whether it is associated with atherosclerotic disease. Methods: We used Southern blot analysis to determine the methylation state of the ER α gene in human right atrium, aorta, internal mammary artery, saphenous vein, coronary atherectomy samples, as well as cultured aortic endothelial cells and smooth muscle cells. Results: An age related increase in ER α gene methylation occurs in the right atrium (range 6 to 19%, R =0.36, P