Apolipoproteins A-I and B: biosynthesis, role in the development of atherosclerosis and targets for intervention against cardiovascular disease

Apolipoprotein (apo) AI and apoB are the major apolipoproteins of high- density lipoprotein (HDL) and low-density lipoprotein (LDL), respectively. ApoB assembles the precursor of LDL, very- low- density lipoprotein (VLDL), in the liver. The assembly starts with the formation of a primordial particle, which is converted to VLDL2. The VLDL2 particle is then transferred to the Golgi apparatus and can either be secreted or converted to triglyceriderich VLDL1. We have reviewed this assembly process, the process involved in the storage of triglycerides in cytosolic lipid droplets, and the relationship between these two processes. We also briefl y discuss the formation of HDL. ApoB mediates the interaction between LDL and the arterial wall. Two regions in apoB are involved in this binding. This interaction and its role in the development of atherosclerosis are reviewed. ApoB can be used to measure the number of LDL or VLDL particles present in plasma, as there is one molecule of apoB on each particle. By contrast, the amount of cholesterol and other lipids on each particle varies under different conditions. We address the possibility of using apoAI and apoB levels to estimate the risk of development of cardiovascular diseases and to monitor intervention to treat these diseases.