Regulation of Scavenger Receptor Class BI Gene Expression by Angiotensin II in Vascular Endothelial Cells

Abstract

Abstract-High-density lipoprotein mediates a normal physiological process called reverse cholesterol transport. In this process, a scavenger receptor of the B class (SR-BI)/human homologue of SR-BI, CD36, and LIMPII analogous-1 (hSR-BI/CLA-1) facilitates the cellular uptake of cholesterol from high-density lipoprotein. 1,2 In this process, HDL particles shuttle cholesterol from extrahepatic tissues to the liver for further metabolism and excretion. 1 Enhanced reverse cholesterol transport lowers total body cholesterol and thereby reduces the risk of developing coronary artery disease. Thus, the plasma concentration of HDL is inversely related to the incidence of coronary artery disease. 3 The mouse scavenger receptor class BI (SR-BI) mediates selective uptake of HDL cholesterol ester into transfected Chinese hamster ovary cells. This finding provides an important link between a specific cell surface receptor and a pathway for the uptake of HDL. 4 Our previous reports show that human homologue of SR-BI, CD36, and LIMPII analogous-1 (hSR-BI/CLA-1), like mouse SR-BI, functions as a receptor for HDL. 5,6 However, the mechanisms by which HDL is atheroprotective are complex and not well understood.Endothelial dysfunction plays a pivotal role in the initiation and progression of atherosclerosis. In fact, the vascular endothelium modulates the vessel tone by releasing both relaxing and contractile factors, 7 regulates the adherence of mononuclear cells to its surface and the vascular permeability, 8,9 and produces substances involved in the regulation of hemostasis and tissue proliferation. 10 The release of NO by endothelial NO synthase (eNOS) is important in the regulation of cardiovascular homeostasis. Recent reports indicated that SR-BI and eNOS are colocalized in vascular endothelial cells. Thus, HDL activates eNOS via SR-BI, and the resulting

c-Jun N-terminal kinases inhibitor suppresses the TNF-α induced MCP-1 expression in human umbilical vein endothelial cells

“…Polymerase chain reactions (PCRs) were performed in a final volume of 20 ll in LightCycler (Roche, Mannheim, Germany) glass capillaries as described previously [13]. The reaction mixture consisted of 2 ll LightCycler-FastStart DNA Master SYBR Green I (Roche), 2.4 ll 25 mM MgCl2 stock solution, 11.6 ll sterile PCR-grade H 2 O, 2 ll of the cDNA template for each gene of interest, and 1 ll of 10 lM of each primer.…”

Extrahepatic High-Density Lipoprotein Receptor SR-BI and ApoA-I Protect Against Deep Vein Thrombosis in Mice

“…SR-BI, a member of the CD36 family of proteins, is a multiligand receptor expressed on many cells, such as hepatocytes, macrophages, endothelial cells (including endothelium in veins 15 ) and platelets. 14,16,17,18 It plays an important role in protection against murine atherosclerosis.…”

Human scavenger receptor class b type 1 is regulated by activators of peroxisome proliferators-activated receptor-γ in hepatocytes

“…Known amounts of DNA were then diluted to provide standards and a regression curve of crossing points versus concentration generated with the LightCycler. GAPDH was used as a standard, as described in an earlier study [15].…”

“…Previous reports, including results from our laboratory [6,10], showed that cells take up CE from HDL by a selective non-endocytotic pathway. Our previous studies showed that the human homologue of SR-B1 (hSR-B1), CD36 and LIMPII Analogous-1 (CLA-1), functions as a receptor for HDL, similar to the mouse homologue [6,[11][12][13][14][15].…”