ABSTRACT
Both lipoproteins and the endothelium play critical roles in the initiation and progression
of atherosclerosis. An understanding of the interactions between lipoproteins and
the endothelium facilitates our understanding of atherogenesis and could suggest new
therapeutic targets. Lipoproteins have important effects on endothelial cells. Atherogenic
lipoproteins such as remnants, low-density lipoprotein (LDL), and oxidized LDL act
on endothelial cells to cause upregulation of endothelial adhesion molecules and selectins,
promotion of oxygen radicals, increased apoptosis, and reduced endothelium-dependent
relaxation. Antiatherogenic lipoproteins such as HDL protect endothelial cells from
oxidative stress and apoptosis and reduce adhesion molecule expression. Conversely,
the endothelium has major effects on lipoprotein metabolism and function. Several
lipases, including lipoprotein lipase, hepatic lipase, endothelial lipase, and secretory
phospholipase A2, are bound to the endothelial cell matrix and have the ability to
hydrolyze lipoprotein triglycerides and phospholipids. Furthermore, endothelial cells
express a variety of lipoprotein receptors including the VLDL receptor, scavenger
receptor A, SR-BI, CD36, and LOX-1, although little is known about their function
on endothelial cells. Although a great deal is known about endothelial-lipoprotein
interactions, more research is needed in this important area.
KEYWORD
Endothelium - lipids - atherogenesis - lipoproteins - vascular biology