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: M600055-JLR200v1 47/8/1833    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 Christoffersen, C. Articles by Dahlbäck, B. Search for Related Content PubMed PubMed Citation Articles by Christoffersen, C. Articles by Dahlbäck, B. Social Bookmarking                      What's this?

Journal of Lipid Research, Vol. 47, 1833-1843, August 2006
Copyright © 2006 by American Society for Biochemistry and Molecular Biology

Isolation and characterization of human apolipoprotein M-containing lipoproteins

Christina Christoffersen^*, Lars Bo Nielsen^*,1, Olof Axler, Astra Andersson, Anders H. Johnsen^* and Björn Dahlbäck^1,

^* Department of Clinical Biochemistry, Rigshospital, University of Copenhagen, Copenhagen DK-2100, Denmark
Department of Laboratory Medicine, Division of Clinical Chemistry, University of Lund, University Hospital, SE-20502 Malmö, Sweden

Published, JLR Papers in Press, May 8, 2006.

¹ To whom correspondence should be addressed. e-mail: larsbo{at}rh.dk (L.B.N.); bjorn.dahlback{at}med.lu.se (B.D.)

Apolipoprotein M (apoM) is a novel apolipoprotein with unknown function. In this study, we established a method for isolating apoM-containing lipoproteins and studied their composition and the effect of apoM on HDL function. ApoM-containing lipoproteins were isolated from human plasma with immunoaffinity chromatography and compared with lipoproteins lacking apoM. The apoM-containing lipoproteins were predominantly of HDL size; 5% of the total HDL population contained apoM. Mass spectrometry showed that the apoM-containing lipoproteins also contained apoJ, apoA-I, apoA-II, apoC-I, apoC-II, apoC-III, paraoxonase 1, and apoB. ApoM-containing HDL (HDL^apoM+) contained significantly more free cholesterol than HDL lacking apoM (HDL^apoM–) (5.9 ± 0.7% vs. 3.2 ± 0.5%; P < 0.005) and was heterogeneous in size with both small and large particles. HDL^apoM+ inhibited Cu²⁺-induced oxidation of LDL and stimulated cholesterol efflux from THP-1 foam cells more efficiently than HDL^apoM–. In conclusion, our results suggest that apoM is associated with a small heterogeneous subpopulation of HDL particles. Nevertheless, apoM designates a subpopulation of HDL that protects LDL against oxidation and stimulates cholesterol efflux more efficiently than HDL lacking apoM.

Abbreviations: apoM, apolipoprotein M; HRP, haptoglobin-related protein; PON1, paraoxonase 1

Supplementary key words cholesterol efflux • oxidation • apoM

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

This article has been cited by other articles:

				J. Ahnstrom, O. Axler, M. Jauhiainen, V. Salomaa, A. S. Havulinna, C. Ehnholm, R. Frikke-Schmidt, A. Tybjaerg-Hansen, and B. Dahlback Levels of apolipoprotein M are not associated with the risk of coronary heart disease in two independent case-control studies J. Lipid Res., September 1, 2008; 49(9): 1912 - 1917. [Abstract] [Full Text] [PDF]

				C. Christoffersen, J. Ahnstrom, O. Axler, E. I. Christensen, B. Dahlback, and L. B. Nielsen The Signal Peptide Anchors Apolipoprotein M in Plasma Lipoproteins and Prevents Rapid Clearance of Apolipoprotein M from Plasma J. Biol. Chem., July 4, 2008; 283(27): 18765 - 18772. [Abstract] [Full Text] [PDF]

				C. Wolfrum, J. J. Howell, E. Ndungo, and M. Stoffel Foxa2 Activity Increases Plasma High Density Lipoprotein Levels by Regulating Apolipoprotein M J. Biol. Chem., June 13, 2008; 283(24): 16940 - 16949. [Abstract] [Full Text] [PDF]

				N. Venteclef, A. Haroniti, J.-J. Tousaint, I. Talianidis, and P. Delerive Regulation of Anti-atherogenic Apolipoprotein M Gene Expression by the Orphan Nuclear Receptor LRH-1 J. Biol. Chem., February 15, 2008; 283(7): 3694 - 3701. [Abstract] [Full Text] [PDF]

				C. Christoffersen, M. Jauhiainen, M. Moser, B. Porse, C. Ehnholm, M. Boesl, B. Dahlback, and L. B. Nielsen Effect of Apolipoprotein M on High Density Lipoprotein Metabolism and Atherosclerosis in Low Density Lipoprotein Receptor Knock-out Mice J. Biol. Chem., January 25, 2008; 283(4): 1839 - 1847. [Abstract] [Full Text] [PDF]

				J. Ahnstrom, K. Faber, O. Axler, and B. Dahlback Hydrophobic ligand binding properties of the human lipocalin apolipoprotein M J. Lipid Res., August 1, 2007; 48(8): 1754 - 1762. [Abstract] [Full Text] [PDF]

				O. Axler, J. Ahnstrom, and B. Dahlback An ELISA for apolipoprotein M reveals a strong correlation to total cholesterol in human plasma J. Lipid Res., August 1, 2007; 48(8): 1772 - 1780. [Abstract] [Full Text] [PDF]