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: M200285-JLR200v1 43/12/2095    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ring, A. Articles by Stremmel, W. Search for Related Content PubMed PubMed Citation Articles by Ring, A. Articles by Stremmel, W. Social Bookmarking                      What's this?

Journal of Lipid Research, Vol. 43, 2095-2104, December 2002
Copyright © 2002 by Lipid Research, Inc.

Evidence for vesicles that mediate long-chain fatty acid uptake by human microvascular endothelial cells

Axel Ring^1,*, Jürgen Pohl^*, Alfred Völkl and Wolfgang Stremmel^2,*

^* Department of Internal Medicine IV, Ruprecht-Karls-University, Heidelberg, Germany
Department of Anatomy and Cell Biology, Ruprecht-Karls-University, Heidelberg, Germany

² To whom correspondence should be addressed. e-mail: wolfgang_stremmel{at}med.uni-heidelberg.de

This study analyzes the mechanisms of long-chain fatty acid (LCFA) uptake by human microvascular endothelial cells (HMEC). The time course revealed the presence of an early, carrier-mediated uptake component and a later component mediated by clathrin-coated vesicles (CCV) and caveolae, as evidenced by three different experimental approaches: 1) significant reduction of [³H]oleate uptake over 5 min by either inhibition of CCV formation by potassium depletion or hypertonic medium, or disruption of caveolae by filipin III or cyclodextrin. 2) Co-localization of intracellular 12-(N-methyl)-N-[(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]octadecanoic acid with CCV and caveolae using confocal laser scanning microscopy. 3) Enrichment of [³H]oleate in a subcellular fraction containing CCV and caveolae. Within 10 min, more than 75% of intracellular [³H]oleate remained unmetabolized, suggesting that HMEC preferentially shuttle LCFA through the cell using CCV and caveolae as carriers. The uptake of albumin paralleled that of oleate within the first 10 min, suggesting internalization of at least some LCFA bound to albumin. Compared to oleate and albumin, the uptake of sucrose and dextran was low, indicating a potential minor contribution of fluid-phase endocytosis to the total vesicular LCFA uptake.

The data indicate a previously unrecognized role of both CCV and caveolae for the uptake of LCFA by HMEC.

Abbreviations: CCV, clathrin-coated vesicles; FAT, fatty acid translocase, HMEC, human microvascular endothelial cells; LCFA, long-chain fatty acids; LSM, laser scanning microscopy; 12-NBD, stearate 12-(N-methyl)-N-[(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]stearate; NEM, N-ethylmaleimide

Supplementary key words clathrin-coated vesicles • caveolae • clathrin-coated vesicles

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

This article has been cited by other articles:

				B. Kiens Skeletal Muscle Lipid Metabolism in Exercise and Insulin Resistance Physiol Rev, January 1, 2006; 86(1): 205 - 243. [Abstract] [Full Text] [PDF]

				J. Pohl, A. Ring, U. Korkmaz, R. Ehehalt, and W. Stremmel FAT/CD36-mediated Long-Chain Fatty Acid Uptake in Adipocytes Requires Plasma Membrane Rafts Mol. Biol. Cell, January 1, 2005; 16(1): 24 - 31. [Abstract] [Full Text] [PDF]

				C. Roepstorff, B. Vistisen, K. Roepstorff, and B. Kiens Regulation of plasma long-chain fatty acid oxidation in relation to uptake in human skeletal muscle during exercise Am J Physiol Endocrinol Metab, October 1, 2004; 287(4): E696 - E705. [Abstract] [Full Text] [PDF]

				B. Vistisen, K. Roepstorff, C. Roepstorff, A. Bonen, B. van Deurs, and B. Kiens Sarcolemmal FAT/CD36 in human skeletal muscle colocalizes with caveolin-3 and is more abundant in type 1 than in type 2 fibers J. Lipid Res., April 1, 2004; 45(4): 603 - 609. [Abstract] [Full Text] [PDF]