HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: M300319-JLR200v1 45/2/272    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Webb, N. R. Articles by van der Westhuyzen, D. R. Search for Related Content PubMed PubMed Citation Articles by Webb, N. R. Articles by van der Westhuyzen, D. R. Social Bookmarking                      What's this?

Journal of Lipid Research, Vol. 45, 272-280, February 2004
Copyright © 2004 by American Society for Biochemistry and Molecular Biology

ApoB-containing lipoproteins in apoE-deficient mice are not metabolized by the class B scavenger receptor BI

Nancy R. Webb^a,b, Maria C. de Beer^a,b, Frederick C. de Beer^a,b and Deneys R. van der Westhuyzen^a,b

^a Department of Internal Medicine, University of Kentucky Medical Center, Lexington, KY 40536
^b Department of Veterans Affairs Medical Center, Lexington, KY 40511

To whom correspondence should be addressed. e-mail: nrwebb1{at}uky.edu

The scavenger receptor class B type I (SR-BI) recognizes a broad variety of lipoprotein ligands, including HDL, LDL, and oxidized LDL. In this study, we investigated whether SR-BI plays a role in the metabolism of cholesterol-rich lipoprotein remnants that accumulate in apolipoprotein E (apoE)^-/- mice. These particles have an unusual apolipoprotein composition compared with conventional VLDL and LDL, containing mostly apoB-48 as well as substantial amounts of apoA-I and apoA-IV. To study SR-BI activity in vivo, the receptor was overexpressed in apoE^-/- mice by adenoviral vector-mediated gene transfer. An 10-fold increase in liver SR-BI expression resulted in no detectable alterations in VLDL-sized particles and a modest depletion of cholesterol in intermediate density lipoprotein/LDL-sized lipoprotein particles. This decrease was not attributable to altered secretion of apoB-containing lipoproteins in SR-BI-overexpressing mice. To directly assess whether SR-BI metabolizes apoE^-/- mouse lipoprotein remnants, in vitro assays were performed in both CHO cells and primary hepatocytes expressing high levels of SR-BI. This analysis showed a remarkable deficiency of these particles to serve as substrates for selective lipid uptake, despite high-affinity, high-capacity binding to SR-BI.

Taken together, these data establish that SR-BI does not play a direct role in the metabolism of apoE^-/- mouse lipoprotein remnants.

Abbreviations: apoE, apolipoprotein E; CE, cholesteryl ester; CEt, cholesteryl ether; LDLR, LDL receptor; SR-BI, scavenger receptor class B type I

Supplementary key words selective lipid uptake • lipoprotein metabolism • adenoviral vector • hepatocytes • apolipoprotein B • apolipoprotein E

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				H. Wiersma, N. Nijstad, T. Gautier, J. Iqbal, F. Kuipers, M. M. Hussain, and U. J. F. Tietge Scavenger receptor BI facilitates hepatic very low density lipoprotein production in mice J. Lipid Res., March 1, 2010; 51(3): 544 - 553. [Abstract] [Full Text] [PDF]

				M. Van Eck, M. Hoekstra, R. Out, I. S. T. Bos, J. K. Kruijt, R. B. Hildebrand, and T. J. C. Van Berkel Scavenger receptor BI facilitates the metabolism of VLDL lipoproteins in vivo J. Lipid Res., January 1, 2008; 49(1): 136 - 146. [Abstract] [Full Text] [PDF]

				A. Nilsson and R.-D. Duan Absorption and lipoprotein transport of sphingomyelin J. Lipid Res., January 1, 2006; 47(1): 154 - 171. [Abstract] [Full Text] [PDF]

				R. Out, M. Hoekstra, S. C. A. de Jager, P. de Vos, D. R. van der Westhuyzen, N. R. Webb, M. Van Eck, E. A. L. Biessen, and T. J. C. Van Berkel Adenovirus-mediated hepatic overexpression of scavenger receptor class B type I accelerates chylomicron metabolism in C57BL/6J mice J. Lipid Res., June 1, 2005; 46(6): 1172 - 1181. [Abstract] [Full Text] [PDF]

				Z. Zhao, M. C. de Beer, L. Cai, R. Asmis, F. C. de Beer, W. J.S. de Villiers, and D. R. van der Westhuyzen Low-Density Lipoprotein From Apolipoprotein E-Deficient Mice Induces Macrophage Lipid Accumulation in a CD36 and Scavenger Receptor Class A-Dependent Manner Arterioscler Thromb Vasc Biol, January 1, 2005; 25(1): 168 - 173. [Abstract] [Full Text] [PDF]

				R. Out, J. K. Kruijt, P. C. N. Rensen, R. B. Hildebrand, P. de Vos, M. Van Eck, and T. J. C. Van Berkel Scavenger Receptor BI Plays a Role in Facilitating Chylomicron Metabolism J. Biol. Chem., April 30, 2004; 279(18): 18401 - 18406. [Abstract] [Full Text] [PDF]