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

J. Biol. Chem., Vol. 280, Issue 2, 1306-1320, January 14, 2005

This Article Full Text Full Text (PDF) All Versions of this Article: 280/2/1306    most recent M406309200v1 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 Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kramer, W. Articles by Schmitz, G. Search for Related Content PubMed PubMed Citation Articles by Kramer, W. Articles by Schmitz, G. Social Bookmarking                      What's this?

Aminopeptidase N (CD13) Is a Molecular Target of the Cholesterol Absorption Inhibitor Ezetimibe in the Enterocyte Brush Border Membrane^*

Werner Kramer, Frank Girbig, Daniel Corsiero, Anja Pfenninger, Wendelin Frick, Gerhard Jähne, Matthias Rhein, Wolfgang Wendler, Friedrich Lottspeich¶, Elisabeth O. Hochleitner¶, Evelyn Orsó||, and Gerd Schmitz||

From the Aventis Pharma Deutschland GmbH, ein Unternehmen der sanofi-aventis-Gruppe, D-65926 Frankfurt am Main, Germany, the ^¶Max-Planck-Institut für Biochemie, D-82152 Martinsried, Germany, and the ^||Institute for Clinical Chemistry and Laboratory Medicine, University of Regensburg, D-93042 Regensburg, Germany

Intestinal cholesterol absorption is an important regulator of serum cholesterol levels. Ezetimibe is a specific inhibitor of intestinal cholesterol absorption recently introduced into medical practice; its mechanism of action, however, is still unknown. Ezetimibe neither influences the release of cholesterol from mixed micelles in the gut lumen nor the transfer of cholesterol to the enterocyte brush border membrane. With membrane-impermeable Ezetimibe analogues we could demonstrate that binding of cholesterol absorption inhibitors to the brush border membrane of small intestinal enterocytes from the gut lumen is sufficient for inhibition of cholesterol absorption. A 145-kDa integral membrane protein was identified as the molecular target for cholesterol absorption inhibitors in the enterocyte brush border membrane by photoaffinity labeling with photoreactive Ezetimibe analogues (Kramer, W., Glombik, H., Petry, S., Heuer, H., Schäfer, H. L., Wendler, W., Corsiero, D., Girbig, F., and Weyland, C. (2000) FEBS Lett. 487, 293–297). The 145-kDa Ezetimibe-binding protein was purified by three different methods and sequencing revealed its identity with the membrane-bound ectoenzyme aminopeptidase N ((alanyl)aminopeptidase; EC 3.4.11.2; APN; leukemia antigen CD13). The enzymatic activity of APN was not influenced by Ezetimibe (analogues). The uptake of cholesterol delivered by mixed micelles by confluent CaCo-2 cells was partially inhibited by Ezetimibe and nonabsorbable Ezetimibe analogues. Preincubation of confluent CaCo-2 cells with Ezetimibe led to a strong decrease of fluorescent APN staining with a monoclonal antibody in the plasma membrane. Independent on its enzymatic activity, aminopeptidase N is involved in endocytotic processes like the uptake of viruses. Our findings suggest that binding of Ezetimibe to APN from the lumen of the small intestine blocks endocytosis of cholesterol-rich membrane microdomains, thereby limiting intestinal cholesterol absorption.

Received for publication, June 7, 2004 , and in revised form, October 12, 2004.

^* The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

To whom correspondence should be addressed: Aventis Pharma Deutschland GmbH, A Group of Sanofi-Aventis, Disease Group Metabolic Diseases, Industriepark Höchst, Bldg. G 879, D-65926 Frankfurt am Main, Germany. Tel.: 49-69-305-3557; Fax: 49-69-305-13333; E-mail: Werner.Kramer{at}aventis.com.

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

This article has been cited by other articles:

				M. A. Valasek, S. L. Clarke, and J. J. Repa Fenofibrate reduces intestinal cholesterol absorption via PPAR{alpha}-dependent modulation of NPC1L1 expression in mouse J. Lipid Res., December 1, 2007; 48(12): 2725 - 2735. [Abstract] [Full Text] [PDF]

				N. Petrovic, W. Schacke, J. R. Gahagan, C. A. O'Conor, B. Winnicka, R. E. Conway, P. Mina-Osorio, and L. H. Shapiro CD13/APN regulates endothelial invasion and filopodia formation Blood, July 1, 2007; 110(1): 142 - 150. [Abstract] [Full Text] [PDF]

				J. J. Clarenbach, M. Reber, D. Lutjohann, K. von Bergmann, and T. Sudhop The lipid-lowering effect of ezetimibe in pure vegetarians J. Lipid Res., December 1, 2006; 47(12): 2820 - 2824. [Abstract] [Full Text] [PDF]

				F. Lalloyer, C. Fievet, S. Lestavel, G. Torpier, J. van der Veen, V. Touche, S. Bultel, S. Yous, F. Kuipers, R. Paumelle, et al. The RXR Agonist Bexarotene Improves Cholesterol Homeostasis and Inhibits Atherosclerosis Progression in a Mouse Model of Mixed Dyslipidemia Arterioscler. Thromb. Vasc. Biol., December 1, 2006; 26(12): 2731 - 2737. [Abstract] [Full Text] [PDF]

				T. Plosch, J. K. Kruit, V. W. Bloks, N. C. A. Huijkman, R. Havinga, G. S. M. J. E. Duchateau, Y. Lin, and F. Kuipers Reduction of Cholesterol Absorption by Dietary Plant Sterols and Stanols in Mice Is Independent of the Abcg5/8 Transporter J. Nutr., August 1, 2006; 136(8): 2135 - 2140. [Abstract] [Full Text] [PDF]

				L. Yu, S. Bharadwaj, J. M. Brown, Y. Ma, W. Du, M. A. Davis, P. Michaely, P. Liu, M. C. Willingham, and L. L. Rudel Cholesterol-regulated Translocation of NPC1L1 to the Cell Surface Facilitates Free Cholesterol Uptake J. Biol. Chem., March 10, 2006; 281(10): 6616 - 6624. [Abstract] [Full Text] [PDF]

				E. Reboul, A. Klein, F. Bietrix, B. Gleize, C. Malezet-Desmoulins, M. Schneider, A. Margotat, L. Lagrost, X. Collet, and P. Borel Scavenger Receptor Class B Type I (SR-BI) Is Involved in Vitamin E Transport across the Enterocyte J. Biol. Chem., February 24, 2006; 281(8): 4739 - 4745. [Abstract] [Full Text] [PDF]

				L. Jakulj, M. D. Trip, T. Sudhop, K. von Bergmann, J. J. P. Kastelein, and M. N. Vissers Inhibition of cholesterol absorption by the combination of dietary plant sterols and ezetimibe: effects on plasma lipid levels J. Lipid Res., December 1, 2005; 46(12): 2692 - 2698. [Abstract] [Full Text] [PDF]

				M. Garcia-Calvo, J. Lisnock, H. G. Bull, B. E. Hawes, D. A. Burnett, M. P. Braun, J. H. Crona, H. R. Davis Jr., D. C. Dean, P. A. Detmers, et al. The target of ezetimibe is Niemann-Pick C1-Like 1 (NPC1L1) PNAS, June 7, 2005; 102(23): 8132 - 8137. [Abstract] [Full Text] [PDF]