出版社：American Society for Biochemistry and Molecular Biology
摘要：Unlike macrophages, the hepatic parenchymal cells express cholesterol-7α-hydroxylase (CYP7A1) which regulates the conversion of cholesterol into bile acids, the major quantitative pathway maintaining cholesterol homeostasis. We examined if CYP7A1 expression in RAW 264.7 macrophages could prevent the accumulation of cholesterol when they were incubated with acetyl-LDL. A single cell clone (designated as 7αRAW cells) that stably expresses rat CYP7A1 displayed similar rates of growth as non-transfected RAW cells. The CYP7A1 enzymatic activity expressed by microsomes obtained from 7αRAW cells was similar to that expressed by microsomes obtained from mouse liver. Incubating non-transfected RAW with increasing amounts of acetyl-LDL caused a parallel accumulation of cholesterol, whereas 7αRAW cells displayed a complete resistance to cholesterol accumulation. 7αRAW cells displayed increased expression of both ABCA1 mRNA (3.1-fold, P P 3H]cholesterol to both delipidated apolipoprotein A1 and to HDL. Thus, CYP7A1 expression in RAW cultured macrophages prevented the accumulation of cholesterol from acetyl-LDL via both increased metabolism and efflux of cholesterol. —Moore, G. L., and R. A. Davis. Expression of cholesterol-7 α-hydroxylase in murine macrophages prevents cholesterol loading by acetyl-LDL. J. Lipid Res. 2002. 43: 629–635.
关键词：atherosclerosis ; bile acids ; cholesterol-7 α-hydroxylase ; lipoproteins
