The expression of ABCG1 transporter gene in peripheral blood mononuclear cells of patients with atherosclerosis

Abstract

The antiatherogenic role of high-density lipoproteins (HDL) was demonstrated by numerous experimental, clinical and epidemiological studies. The mechanism underlying the antiatherogenic potential of HDL is based on their involvement in reverse cholesterol transport (RCT) from peripheral tissues into the liver. Transmembrane transporter ABCG1 is a key RCT protein. Its function is to remove cholesterol from cells and transfer it to HDL. The role of ABCG1 transporter in the development of atherosclerosis in humans remains unexplored. The goal of our study was to investigate the expression of ABCG1 gene in patients with atherosclerosis. Real-time PCR was applied to study ABCG1 mRNA content in leukocytes, monocytes, and macrophages activated with macrophage colony-stimulating factor (M-CSF) from patients with atherosclerosis and healthy people. The amount of ABCG1 protein in monocytes and macrophages of patients and healthy donors was assayed by immunoblotting. It was found that the level of ABCG1 mRNA (p < 0.001) and ABCG1 protein (p < 0.05) was lower in macrophages of patients with atherosclerosis. The level of ABCG1 mRNA in monocytes of patients with artery occlusion was lower than in patients with features of lesser stenosis and the control group (p < 0.05). No correlation was found between ABCG1 gene expression and total and HDL cholesterol levels in the blood plasma. It can be concluded that reduced ABCG1 gene expression in monocytes and macrophages may be critical for the atherosclerosis progression.