Poster Sessions

MOLBIO/BIOCHEM/BIOPHYS-2

Mona Ghias

M. Ghias, B. Vaisman, A. Remaley

The Expression of Scavenger Receptor-B1 in the Endothelium Prevents Atherosclerosis

The SR-BI receptor plays a key role in cholesterol trafficking and lipoprotein metabolism. It is responsible for the selective uptake of cholesterol ester from HDL by hepatocytes and steroidogenic cells, and participates in cholesterol efflux in different types of cells. It has been previously shown that SR-B1 expression in the liver is atheroprotective. We recently determined that lung and aortic endothelial cells also have a relatively high level of expression of SR-B1. In order to investigate the possible role of SRB1 in the endothelium, transgenic mice with mouse SR-B1 gene under control of an endothelial specific Tie2 promoter were created. The transgene was transferred also on apoE-Ko, and SR-B1-Ko backgrounds. Mice on normal and SRB1-Ko background were placed on a high fat/high cholesterol diet for three months. The expression of SR-B1 in the endothelium did not significantly change the plasma lipid and lipoprotein profiles in the various mouse models. Analysis of the aorta of these mice revealed that on apoE-Ko and normal background transgenic mice had, respectively, 25% and 33% less lesions than control mice. The created mouse models will enable future studies to determine the mechanism for the atheroprotective effect of SR-B1 in the endothelial cells.