Chapter 1 - Role of Phospholipid Transfer Protein in HDL Remodeling and Atherosclerosis

Abstract

This chapter discusses the role of phospholipid transfer protein (PLTP) in high density lipoprotein (HDL) remodeling and atherosclerosis. PLTP plays an important role in the regulation of HDL metabolism. The regulatory role of PLTP is achieved via its two main functions, PLTP and the ability to modulate HDL size and composition in a process called HDL remodeling. The regulation of HDL metabolism is achieved by the concerted action of a number of plasma and cellular factors such as cellular receptors, scavenger receptor class B type 1 and ATP-binding cassette transporter A1, as well as plasma proteins such as cholesteryl ester transfer protein (CETP), lecithin-cholesterol acyltransferase, and the endothelial-bound enzymes, lipoprotein lipase (LPL) and triglyceride (TG) hydrolase hepatic lipase (HL). Preβ-HDL particles, a subpopulation of HDL, act as efficient acceptors in the efflux process of cholesterol at the plasma membrane of peripheral cells. PLTP is able to generate preb-HDL particles through HDL remodeling and has a major role also in maintaining plasma HDL levels owing to its ability to transport surface remnants produced by lipolysis of triglyceride-rich lipoproteins. Thus, PLTP can be envisioned to play an important role in the prevention of atherosclerosis. In humans, both CETP and PLTP catalyze the conversion of HDL in vitro into larger and smaller particles, including preb-HDL. The physiological significance of this process is that it increases the production of preb-HDL and thereby enhances the capacity of HDL to accept cellular cholesterol.