High-density lipoproteins protect endothelial cells from apoptosis induced by oxidized low-density lipoproteins

Abstract

Summary. Endotheliai lesion by oxidized low-density liproproteins(LDL) is one of the first stages in the development of atherosclerosis. The effect of these lipoproteins can range from a functional lesion of the endothelium to death of the endothelial cells by apoptosis. High-density lipoproteins (HDL) are one of the factors which can have a protective effect against the development of atheromatous plaques. The aim of this study is to establish whether the death of endothelial cells by apoptosis induced by oxidized LDLs is prevented by HDLs. ECV304 endothelial cells and bovine aorta endothelial cells were incubated with native LDLs, oxidized LDLs, and a combination of both oxidized LDLs and HDLs. Oxidized LDLs caused a significant increase of mortality mainly by apoptosis. However, when HDLs were added together with oxidized LDLs the percentage of total mortality, the degree of lipoprotein oxidation in the medium, and the percentage of cells in apoptosis were all significantly decreased. HDLs protect against the cytotoxicity of oxidized LDLs possibly by preventing the propagation of the oxidative chain in these lipoproteins.

A Review on the Traditional Chinese Medicinal Herbs and Formulae with Hypolipidemic Effect

“…These small dense LDL particles have weaker interaction with LDLR and stay longer than normal LDL in the blood so they readily penetrate through endothelial fenestrations to accumulate in the subendothelial space [ 30 ] where they are oxidized by reactive oxidative species (ROS) such as superoxide generated by endothelial cells [ 31 ] and activated leukocytes [ 32 ]. The oxidized LDL (ox-LDL) is a key component in the development of endothelial lesion [ 33 , 34 ]. It can induce endothelial expression and secretion of cytokines, growth factors, and several cell surface adhesion molecules that are capable of recruiting circulating monocytes and T lymphocytes into the intima.…”