Fig. 1

Anti-atherogenic features of HDL. Atherosclerosis is an inflammatory condition initiated by accumulation and subsequent oxidation of LDL in the arterial intima. Ox-LDL promotes differentiation of monocytes into macrophages that scavenge ox-LDL and transform into foam cells. Macrophages express cytokines which stimulate the endothelium to express adhesion molecules leading to interaction with circulating monocytes. 1) HDL inhibits expression of adhesion molecules on the epithelium and thereby inhibits monocyte chemotaxis and formation of foam cells. 2) HDL mediates cholesterol efflux and thereby decreases the accumulation of foam cells. 3) The primarily antioxidative effect of HDL is inhibition of oxidation of LDL. HDL: high-density lipoprotein; LDL: low-density lipoprotein; ox-LDL: oxidized low-density lipoprotein. (Inspired by Barter et al. 2004)