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: M500466-JLR200v1 47/3/605    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 Zimetti, F. Articles by Rothblat, G. H. Search for Related Content PubMed PubMed Citation Articles by Zimetti, F. Articles by Rothblat, G. H. Social Bookmarking                      What's this?

Journal of Lipid Research, Vol. 47, 605-613, March 2006
Copyright © 2006 by American Society for Biochemistry and Molecular Biology

Measurement of cholesterol bidirectional flux between cells and lipoproteins

Francesca Zimetti, Ginny K. Weibel, MyNgan Duong and George H. Rothblat¹

Gastrointestinal and Nutrition Division, Children's Hospital of Philadelphia, Philadelphia, PA 19104

Published, JLR Papers in Press, December 3, 2005.

¹ To whom correspondence should be addressed. e-mail: rothblat{at}email.chop.edu

We developed an assay that quantitates bidirectional cholesterol flux between cells and lipoproteins. Incubating Fu5AH cells with increasing concentrations of human serum resulted in increased influx and efflux; however, influx was 2- to 3-fold greater at all serum concentrations. With apolipoprotein B (apoB)-depleted serum, the ratio of influx to efflux (I/E) was close to 1, indicating cholesterol exchange. The apoB fraction of serum induced influx and little efflux, with I/E > 1. Using block lipid transport-1 to block scavenger receptor class B type I (SR-BI)-mediated flux with different acceptors, we determined that 50% to 70% of efflux was via SR-BI. With HDL, 90% of influx was via SR-BI, whereas with LDL or serum, 20% of influx was SR-BI-mediated. Cholesterol-enriched hepatoma cells produced increased efflux without a change in influx, resulting in reduced I/E. The assay was applied to cholesterol-normal and -enriched mouse peritoneal macrophages exposed to serum or LDL. The enrichment enhanced efflux without shifts in influx. With cholesterol-enriched macrophages, HDL efflux was enhanced and influx was greatly reduced. With all lipoproteins, cholesterol enrichment of murine peritoneal macrophages led to a reduced I/E. We conclude that this assay can simultaneously and accurately quantitate cholesterol bidirectional flux and can be applied to a variety of cells exposed to isolated lipoproteins or serum.

Supplementary key words efflux • influx • macrophages • hepatoma • ATP binding cassette transporter A1 • scavenger receptor class B type I • high density lipoprotein

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

This article has been cited by other articles:

				S. Rashid, M. Marcil, I. Ruel, and J. Genest Identification of a novel human cellular HDL biosynthesis defect Eur. Heart J., June 24, 2009; (2009) ehp250v1. [Abstract] [Full Text] [PDF]

				S. A. Fenske, A. Yesilaltay, R. Pal, K. Daniels, A. Rigotti, M. Krieger, and O. Kocher Overexpression of the PDZ1 Domain of PDZK1 Blocks the Activity of Hepatic Scavenger Receptor, Class B, Type I by Altering Its Abundance and Cellular Localization J. Biol. Chem., August 8, 2008; 283(32): 22097 - 22104. [Abstract] [Full Text] [PDF]

				M. P. Adorni, F. Zimetti, J. T. Billheimer, N. Wang, D. J. Rader, M. C. Phillips, and G. H. Rothblat The roles of different pathways in the release of cholesterol from macrophages J. Lipid Res., November 1, 2007; 48(11): 2453 - 2462. [Abstract] [Full Text] [PDF]

				T. J. F. Nieland, J. T. Shaw, F. A. Jaipuri, Z. Maliga, J. L. Duffner, A. N. Koehler, and M. Krieger Influence of HDL-cholesterol-elevating drugs on the in vitro activity of the HDL receptor SR-BI J. Lipid Res., August 1, 2007; 48(8): 1832 - 1845. [Abstract] [Full Text] [PDF]

				L. A. Morehouse, E. D. Sugarman, P.-A. Bourassa, T. M. Sand, F. Zimetti, F. Gao, G. H. Rothblat, and A. J. Milici Inhibition of CETP activity by torcetrapib reduces susceptibility to diet-induced atherosclerosis in New Zealand White rabbits J. Lipid Res., June 1, 2007; 48(6): 1263 - 1272. [Abstract] [Full Text] [PDF]

				S. Parathath, Y. F. Darlington, M. de la Llera Moya, D. Drazul-Schrader, D. L. Williams, M. C. Phillips, G. H. Rothblat, and M. A. Connelly Effects of amino acid substitutions at glycine 420 on SR-BI cholesterol transport function J. Lipid Res., June 1, 2007; 48(6): 1386 - 1395. [Abstract] [Full Text] [PDF]

				M. Dreux, T. Pietschmann, C. Granier, C. Voisset, S. Ricard-Blum, P.-E. Mangeot, Z. Keck, S. Foung, N. Vu-Dac, J. Dubuisson, et al. High Density Lipoprotein Inhibits Hepatitis C Virus-neutralizing Antibodies by Stimulating Cell Entry via Activation of the Scavenger Receptor BI J. Biol. Chem., July 7, 2006; 281(27): 18285 - 18295. [Abstract] [Full Text] [PDF]