High-density lipoprotein protects macrophages from oxidized low-density lipoprotein-induced apoptosis by promoting efflux of 7-ketocholesterol via ABCG1.

ABSTRACT: Oxidized sterols consumed in the diet or formed on low-density lipoprotein (LDL) are toxic to endothelial cells and macrophages and are thought to have a central role in promoting atherogenesis. The ATP-binding cassette transporter ABCG1 was recently shown to promote efflux of cholesterol from macrophages to high-denisty lipoprotein (HDL). We show that HDL protects macrophages from apoptosis induced by loading with free cholesterol or oxidized LDL. The protective effect of HDL was reduced in Abcg1(-/-) macrophages, especially after loading with oxidized LDL. Similarly, HDL exerted a protective effect against apoptosis induced by 7-ketocholesterol, the major oxysterol present in oxidized LDL and atherosclerotic lesions, in Abcg1(+/+), but not in Abcg1(-/-) macrophages. In transfected 293 ce

SUBMITTER: Terasaka N 

PROVIDER: S-EPMC1986618 | biostudies-literature | 2007 Sep

REPOSITORIES: biostudies-literature