Native LDL upregulation of ATP-binding cassette transporter-1 in human vascular endothelial cells

Liao, Hailing and Langmann, Thomas and Schmitz, Gerd and Zhu, Yi (2002) Native LDL upregulation of ATP-binding cassette transporter-1 in human vascular endothelial cells. ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY, 22 (1). pp. 127-132. ISSN 1079-5642

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Abstract

ATP-binding cassette transporter-1 (ABCA1) mediates the lipid efflux from cells to apolipoproteins. In studying the gene expression and regulation of ABCA1 in human vascular endothelial cells (ECs), we found that native low density lipoprotein (LDL) elevates ABCA1 in both protein and mRNA levels in a time- and dose-dependent fashion. Transfection of full-length human ABCA1 in ECs lowers cellular cholesterol content and increases apolipoprotein (apo) A-I-mediated cholesterol efflux. Transfection of the ABCA1 promoter-luciferase reporter results in a 2-fold induction after LDL exposure. The responsive element was mapped within - 116 to -54 of the promoter region with use of promoter deletion constructs, as reported in other cells. A mutation of the DR4 site greatly diminished the LDL effect. Results showing that LDL increases the liver X receptor responsive element (LXRE)-driven luciferase activity demonstrate the effect of LDL on LXR activation. Furthermore, ligands of the retinoid X receptor and LXR activate ABCA1 in ECs at levels of both promoter activation and mRNA induction. Therefore, ABCA1 is expressed in vascular ECs and is transcriptionally upregulated by LDL. Overexpression of ABCA1 in these cells prevents overloading of cholesterol by increasing the efflux of cholesterol. Thus, ABCA1 plays an important role in the homeostasis of cholesterol in the vascular endothelium.

Item Type: Article
Uncontrolled Keywords: LOW-DENSITY-LIPOPROTEIN; REVERSE CHOLESTEROL TRANSPORT; TANGIER-DISEASE; NUCLEAR RECEPTOR; PLASMA-MEMBRANE; APOA-I; EFFLUX; GENE; ABC1; EXPRESSION; ABCA1; cholesterol; LDL; liver X receptor; endothelial cells
Subjects: 600 Technology > 610 Medical sciences Medicine
Divisions: Medicine > Lehrstuhl für Klinische Chemie und Laboratoriumsmedizin
Depositing User: Dr. Gernot Deinzer
Date Deposited: 15 Nov 2021 11:27
Last Modified: 15 Nov 2021 11:27
URI: https://pred.uni-regensburg.de/id/eprint/40693

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