Journal
CARDIOVASCULAR RESEARCH
Volume 68, Issue 3, Pages 425-432Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.cardiores.2005.07.003
Keywords
cholesterol; endothelial function; gene expression; lipoprotein; membrane transport
Categories
Funding
- NHLBI NIH HHS [HL 33742] Funding Source: Medline
Ask authors/readers for more resources
Objective: ATP-binding cassette transporter-1 (ABCA1) mediates the active efflux of cholesterol and phospholipids, playing an important role in cholesterol homeostasis and atherogenesis. Oxidized low density lipoprotein (oxLDL) is an atherogenic molecule associated with the vascular endothelial dysfunction and development of atherosclerotic plaque. This report describes the effect of copper-catalyzed oxLDL on the regulation of ABCA1 in human endothelial cells (ECs). Methods and results: oxLDL downregulated ABCA1 at both mRNA and protein levels in a dose-dependent manner. This inhibitory effect of oxLDL was observed with both minimally and extensively oxLDL. Transfection of the ABCA1 promoter luciferase revealed oxLDL to substantially decrease ABCA1 promoter activity at basal conditions and after stimulation by overexpressing the liver X receptor LXR alpha and retinoid X receptor RXR alpha. oxLDL also attenuated LXR activation by blocking LXR ligand binding and interfering with the generation of 27-hydroxycholesterol, an LXR endogenous ligand. Furthermore, oxLDL inhibited exogenous cholesterol- and oxysterol-induced endothelial ABCA1 induction. Conclusion: oxLDL downregulated ABCA1 by inhibiting LXR activation in endothelial cells. Such an effect may contribute to endothelial dysfunction and plaque formation. (c) 2005 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available