Binding of high density lipoproteins to cell receptors promotes translocation of cholesterol from intracellular membranes to the cell surface.

作者：J. Peter Slotte, John F. Oram, E L Bierman · 发表于：Journal of Biological Chemistry · 年份：1987 · DOI：10.1016/s0021-9258(18)45142-3 · 被引用次数：192 · 研究领域：Cholesterol and Lipid Metabolism、Fatty Acid Research and Health、Peroxisome Proliferator-Activated Receptors

Cultured cells have on their cell surface a specific high-affinity binding site (receptor) for high density lipoproteins (HDL) which appears to promote cholesterol efflux. In this study we characterized the cellular mechanisms involved in HDL receptor-mediated transport of cholesterol from cultured human fibroblasts and bovine aortic endothelial cells. HDL3, chemically modified by tetranitromethane (TNM-HDL3), is not recognized by this receptor and was used as a control for efflux not mediated by HDL receptor binding. HDL3 and TNM-HDL3 were found to be equally effective in causing efflux of plasma membrane cholesterol radiolabeled with [3H]cholesterol. However, HDL3 was much more effective than TNM-HDL3 in causing efflux of [3H]cholesterol associated with intracellular membranes. By measuring movement of endogenously synthesized [3H]cholesterol to the plasma membrane, and into the medium, we found that HDL3 induced a rapid movement of [3H]cholesterol from a preplasma membrane compartment to the plasma membrane that preceded [3H]cholesterol efflux. This effect was not observed with TNM-HDL3. Thus, receptor binding of HDL3 appears to facilitate removal of cellular cholesterol from specific intracellular pools by initiation of translocation of intracellular cholesterol to the plasma membrane.