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: M600394-JLR200v1 48/3/565    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 Moumtzi, A. Articles by Hermetter, A. Search for Related Content PubMed PubMed Citation Articles by Moumtzi, A. Articles by Hermetter, A. Social Bookmarking                      What's this?

Journal of Lipid Research, Vol. 48, 565-582, March 2007
Copyright © 2007 by American Society for Biochemistry and Molecular Biology

Import and fate of fluorescent analogs of oxidized phospholipids in vascular smooth muscle cells

Alexandra Moumtzi^1,*, Michael Trenker^1,*, Karlheinz Flicker^*, Elfriede Zenzmaier^*, Robert Saf and Albin Hermetter^2,*

^* Institute of Biochemistry, Graz University of Technology, A-8010 Graz, Austria
Institute for Chemistry and Technology of Organic Materials, Graz University of Technology, A-8010 Graz, Austria

Published, JLR Papers in Press, November 29, 2006.

¹ A. Moumtzi and M. Trenker contributed equally to this work.

² To whom correspondence should be addressed. e-mail: albin.hermetter{at}tugraz.at

Lipid oxidation is now thought to be an initiating and sustaining event in atherogenesis. Oxidatively fragmented phospholipids, namely 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine (PGPC) and 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC), present in minimally modified LDL and atherosclerotic lesions, have been reported to elicit a wide range of pathophysiological responses in the cells of the vascular wall. Nevertheless, the question of their potential sites of action and their primary molecular targets remains open. To address this issue, a series of fluorescently labeled analogs, which differ with regard to structure and binding site of the fluorophore, were synthesized and used as tools for studying the uptake, intracellular stability, and distribution of PGPC and POVPC in vascular smooth muscle cells (VSMCs). We demonstrate that in accordance with their lysophospholipid-like structure, these highly similar molecules transferred rapidly either from aqueous phospholipid dispersions or preloaded native LDL into VSMCs, producing disparate fluorescence patterns irrespective of the attached fluorophore. PGPC derivatives were translocated to the lysosomes. In sharp contrast, POVPC analogs were initially captured in the plasma membrane, most likely in consequence of the formation of covalent adducts with free amino and sulfhydryl groups of proteins and phospholipids. LDL internalization is not required for cellular lipid uptake. Collectively, our data provide evidence that oxidized phospholipids, owing to their high exchangeability between lipoproteins and cell membranes, may act within a short time on different cellular sites in VSMCs and affect various lipid and protein components through physical or chemical interactions, which might then serve as starting points for intracellular signaling.

Supplementary key words atherosclerosis • lipoproteins • lipid synthesis • lipid transport

Abbreviations: AcOH, acetic acid; Alexa647, Alexa Fluor 647; apoB, apolipoprotein B-100; BODIPY, 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; 2-D, two-dimensional; DCC, N,N'-dicyclohexylcarbodiimide; DMAP, p-(N,N-dimethylamino)pyridine; ER, endoplasmic reticulum; EtOH, ethanol; FCS, fetal calf serum; HNE, 4-hydroxy-2-nonenal; MALDI-TOF, matrix-assisted laser desorption/ionization time-of-flight; MeOH, methanol; PGPC, 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine; PGPE, 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphoethanolamine; PLA₂, phospholipase A₂; PLD, phospholipase D; POPE, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine; POVPC, 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine; POVPE, 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphoethanolamine; PyrGPC, 1-(10-pyrenedecanoyl)-2-glutaroyl-sn-glycero-3-phosphocholine; PyrOPC, 1-(10-pyrenedecanoyl)-2-oleoyl-sn-glycero-3-phosphocholine; PyrOVPC, 1-(10-pyrenedecanoyl)-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine; R_f, relative mobility; SE, succinimidyl ester; VSMC, vascular smooth muscle cell

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

This article has been cited by other articles:

				M. Barton, R. Minotti, and E. Haas Inflammation and Atherosclerosis Circ. Res., October 12, 2007; 101(8): 750 - 751. [Full Text] [PDF]

				R. Chen, L. Yang, and T. M. McIntyre Cytotoxic Phospholipid Oxidation Products: CELL DEATH FROM MITOCHONDRIAL DAMAGE AND THE INTRINSIC CASPASE CASCADE J. Biol. Chem., August 24, 2007; 282(34): 24842 - 24850. [Abstract] [Full Text] [PDF]