| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
* Department of Molecular Genetics and McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390
Department of Physiology and Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390
1 To whom correspondence should be addressed. e-mail: liqing.yu{at}utsouthwestern.edu (L.U.); herbert.stangl{at}meduniwien.ac.at (H.S.)
Scavenger receptor class B type I (SR-BI) is expressed in macrophages, but its role in sterol trafficking in these cells remains controversial. We examined the effect of sterol loading on SR-BI expression in human monocytes/macrophages, mouse peritoneal macrophages, and a cultured mouse macrophage cell line (J774 cells). Sterol loading using either acetylated LDL or 25-hydroxycholesterol resulted in a time- and concentration-dependent decrease in SR-BI protein and mRNA levels. Treatment of lipid-loaded J774 cells with cyclodextrin or HDL to promote cellular sterol efflux was associated with an increase in SR-BI expression. Studies were performed to determine if the sterol-associated downregulation of SR-BI in macrophages was mediated by either sterol regulatory element binding proteins (SREBPs) or the liver X receptor (LXR). Expression of constitutively active SREBPs failed to alter the expression of a luciferase reporter placed downstream of a 2,556 bp 5' flanking sequence from the mouse SR-BI gene. Reduction in SR-BI expression was also seen in sterol-loaded peritoneal macrophages from mice expressing no LXR
and LXRß.
We conclude that SR-BI levels in macrophages are responsive to changes in intracellular sterol content and that these sterol-associated changes are not mediated by LXR and are unlikely to be mediated by an SREBP pathway.
Abbreviations: ABC, ATP binding cassette; ac-LDL, acetylated LDL; BAC, bacterial artificial chromosome; FCS, fetal calf serum; 25-HC, 25-hydroxycholesterol; LDLR, LDL receptor; LXR, liver X receptor; M-CSF, macrophage colony-stimulating factor; M-SFM, macrophage serum-free medium; NCLPPS, newborn calf lipoprotein-deficient serum; ox-LDL, oxidized LDL; PPAR, peroxisomal proliferator-activated receptor; RAP, receptor-associated protein; SCAP, SREBP cleavage-activating protein; SF-1, steroidogenic factor 1; SR-BI, scavenger receptor class B type I; SREBP, sterol regulatory element binding protein
Supplementary key words cholesterol • regulation • mouse scavenger receptor class B type I promoter
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  L. Yvan-Charvet, T. A. Pagler, N. Wang, T. Senokuchi, M. Brundert, H. Li, F. Rinninger, and A. R. Tall SR-BI inhibits ABCG1-stimulated net cholesterol efflux from cells to plasma HDL J. Lipid Res., January 1, 2008; 49(1): 107 - 114. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. L. Weibel, E. T. Alexander, M. R. Joshi, D. J. Rader, S. Lund-Katz, M. C. Phillips, and G. H. Rothblat Wild-Type ApoA-I and the Milano Variant Have Similar Abilities to Stimulate Cellular Lipid Mobilization and Efflux Arterioscler. Thromb. Vasc. Biol., September 1, 2007; 27(9): 2022 - 2029. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Yvan-Charvet, F. Matsuura, N. Wang, M. J. Bamberger, T. Nguyen, F. Rinninger, X.-C. Jiang, C. L. Shear, and A. R. Tall Inhibition of Cholesteryl Ester Transfer Protein by Torcetrapib Modestly Increases Macrophage Cholesterol Efflux to HDL Arterioscler. Thromb. Vasc. Biol., May 1, 2007; 27(5): 1132 - 1138. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M.-D. Wang, R. S. Kiss, V. Franklin, H. M. McBride, S. C. Whitman, and Y. L. Marcel Different cellular traffic of LDL-cholesterol and acetylated LDL-cholesterol leads to distinct reverse cholesterol transport pathways J. Lipid Res., March 1, 2007; 48(3): 633 - 645. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. C. Rideout, Z. Yuan, M. Bakovic, Q. Liu, R.-K. Li, Y. Mine, and M. Z. Fan Guar Gum Consumption Increases Hepatic Nuclear SREBP2 and LDL Receptor Expression in Pigs Fed an Atherogenic Diet J. Nutr., March 1, 2007; 137(3): 568 - 572. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Favari, M. Gomaraschi, I. Zanotti, F. Bernini, M. Lee-Rueckert, P. T. Kovanen, C. R. Sirtori, G. Franceschini, and L. Calabresi A Unique Protease-sensitive High Density Lipoprotein Particle Containing the Apolipoprotein A-IMilano Dimer Effectively Promotes ATP-binding Cassette A1-mediated Cell Cholesterol Efflux J. Biol. Chem., February 23, 2007; 282(8): 5125 - 5132. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. B. Kapadia, H. Barth, T. Baumert, J. A. McKeating, and F. V. Chisari Initiation of Hepatitis C Virus Infection Is Dependent on Cholesterol and Cooperativity between CD81 and Scavenger Receptor B Type I J. Virol., January 1, 2007; 81(1): 374 - 383. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Marcil, E. Delvin, A. T. Sane, A. Tremblay, and E. Levy Oxidative stress influences cholesterol efflux in THP-1 macrophages: Role of ATP-binding cassette A1 and nuclear factors Cardiovasc Res, December 1, 2006; 72(3): 473 - 482. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Brundert, J. Heeren, M. Bahar-Bayansar, A. Ewert, K. J. Moore, and F. Rinninger Selective uptake of HDL cholesteryl esters and cholesterol efflux from mouse peritoneal macrophages independent of SR-BI J. Lipid Res., November 1, 2006; 47(11): 2408 - 2421. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Trogan, J. E. Feig, S. Dogan, G. H. Rothblat, V. Angeli, F. Tacke, G. J. Randolph, and E. A. Fisher Gene expression changes in foam cells and the role of chemokine receptor CCR7 during atherosclerosis regression in ApoE-deficient mice. PNAS, March 7, 2006; 103(10): 3781 - 3786. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Zimetti, G. K. Weibel, M. Duong, and G. H. Rothblat Measurement of cholesterol bidirectional flux between cells and lipoproteins J. Lipid Res., March 1, 2006; 47(3): 605 - 613. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. C. Gelissen, M. Harris, K.-A. Rye, C. Quinn, A. J. Brown, M. Kockx, S. Cartland, M. Packianathan, L. Kritharides, and W. Jessup ABCA1 and ABCG1 Synergize to Mediate Cholesterol Export to ApoA-I Arterioscler. Thromb. Vasc. Biol., March 1, 2006; 26(3): 534 - 540. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Duong, H. L. Collins, W. Jin, I. Zanotti, E. Favari, and G. H. Rothblat Relative Contributions of ABCA1 and SR-BI to Cholesterol Efflux to Serum From Fibroblasts and Macrophages Arterioscler. Thromb. Vasc. Biol., March 1, 2006; 26(3): 541 - 547. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Journal of Biological Chemistry |
| Molecular and Cellular Proteomics | ASBMB Today |
