High density lipoproteins and arteriosclerosis - Role of cholesterol efflux and reverse cholesterol transport

High density lipoprotein (HDL) cholesterol is an important risk factor for coronary heart disease, and HDL exerts various potentially antiatherogenic properties, including the mediation of reverse transport of cholesterol fro m cells of the arterial wall to the liver and steroidogenic organs. Enhance ment of cholesterol efflux and of reverse cholesterol transport (RCT) is co nsidered an important target for antiatherosclerotic drug therapy. Levels a nd composition of HDL subclasses in plasma are regulated by many factors, i ncluding apolipoproteins, lipolytic enzymes, lipid transfer proteins, recep tors, and cellular transporters. In vitro experiments as well as genetic fa mily and population studies and investigation of transgenic animal models h ave revealed that HDL cholesterol plasma levels do not necessarily reflect the efficacy and antiatherogenicity of RCT. Instead, the concentration of H DL subclasses, the mobilization of cellular lipids for afflux, and the kine tics of HDL metabolism are important determinants of RCT and the risk of at herosclerosis.