Unravelling high density lipoprotein-apolipoprotein metabolism in human mutants and animal models.
Apolipoprotein A-I plays an essential structural and functional role in HDL metabolism and apolipoprotein A-II has important effects on HDL metabolism and function. Kinetic studies in humans have established that variation in plasma HDL-cholesterol and apolipoprotein A-I concentrations is primarily determined by variation in the rate of apolipoprotein A-I catabolism. In contrast, plasma apolipoprotein A-II levels are primarily determined by the rate of apolipoprotein A-II production. Genetic factors play an important role in modulating the plasma levels of HDL-cholesterol and apolipoproteins A-I and A-II. Studies in humans have established that mutations in genes encoding enzymes that esterify cholesterol (lecithin : cholesterol acyltransferase), transfer cholesterol (cholesteryl ester transfer protein) and hydrolyze lipids (hepatic lipase, lipoprotein lipase) regulate HDL-cholesterol and apolipoprotein A-I levels by modifying the lipid content (and therefore the size) of HDL particles. Recent studies in transgenic and knockout animals have confirmed the key role of HDL lipid-modifying proteins in HDL, apolipoprotein A-I and apolipoprotein A-II metabolism and have expanded our understanding of the role of lipid modification in determining plasma concentrations of HDL-cholesterol and apolipoprotein A-I, as well as the potential functional roles of apolipoprotein A-II.
Rader
D J
DJ
University of Pennsylvania School of Medicine, Philadelphia, USA.
Ikewaki
K
K
D000818:Animals; D001053:Apolipoproteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008075:Lipoproteins, HDL / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation
D001053:Apolipoproteins; D008075:Lipoproteins, HDL