CD36 as a biomarker of atherosclerosis

Atherosclerosis is a chronic inflammatory disorder occurs as a result of mononuclear lymphocyte infiltration to the arterial wall accompanied by smooth muscle cell proliferation and damage in the arterial wall caused by extracellular matrix accumulation. Besides several genetic and environmental factors, increased serum cholesterol and oxidized low density lipoproteins are considered to be major risk factors of the disease. During atherosclerosis, lipoproteins such as LDL become trapped at the site of lesion and are converted to oxLDL. Smooth muscle cells become activated by oxLDL, start to proliferate, and migrate into the intima of the arterial wall. OxLDL provokes a cascade of cellular responses at the atherosclerotic lesion, ultimately leading to formation of atherosclerotic plaques. In this process, scavenger receptors could play a critical role because of their ability to bind oxLDL and their function in transporting lipids and cholesterol into and out of the cells. Scavenger receptors are expressed on macrophages and foam cells in atherosclerotic lesions. CD36 is the most important one among them playing role in atherosclerotic process. CD36 is a raft associated glycosylated protein with an 88kDa molecular weight and various ligands such as oxLDL, apoptotic cells, advanced glycation end products bind to this receptor. It has been shown that mice knockouts for the apolipoprotein E exhibited a marked decrease in atherosclerotic lesions if CD36 gene was made inactive. Previously we have shown that the aortas of cholesterol-fed rabbits showed typical atherosclerotic lesions, detected by macroscopic and microscopic examination, and exhibited an increase in CD36 mRNA expression. In this study, we planned to compare CD36 mRNA expressions in the aortic tissue and peripheral blood mononuclear cells in cholesterol induced atherosclerosis. Our results suggests that CD36 mRNA levels in peripheral blood mononuclear cells reflect the levels in aorta and this might be used as a marker for diagnosis of atherosclerosis.