The EMBO Journal
 
Advanced search
Journal home
Aims and scope
Current issue
Advance Online Publication
Web Focuses
Archive:-
Browse by issue
Browse by subject
Browse by category
Free online sample issue
Press releases
Authors & Referees
Editorial process
Guide for authors
Submit an article
Guide for referees
Editorial Team, Senior Advisors and Advisory Editorial Board
Contact Editorial office
Customer services
Subscribe
Order sample copy
Purchase articles
Reprints and permissions
Contact NPG
Advertising
EMBO
www.embo.org
Article
Subject Categories: Cell & Tissue Architecture | Immunology
The EMBO Journal (2006) 25, 1860–1870, doi:10.1038/sj.emboj.7601082
Published online 6 April 2006
Endocytic receptor LRP together with tPA and PAI-1 coordinates Mac-1-dependent macrophage migration
Chunzhang Cao1, Daniel A Lawrence2, Yang Li1, Christine A F Von Arnim3, Joachim Herz4, Enming J Su2, Alexandra Makarova3, Bradley T Hyman3, Dudley K Strickland1 and Li Zhang1
1 Department of Physiology and Surgery, Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD, USA
2 Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
3 Alzheimer's Disease Research Laboratory, Harvard Medical School, Charlestown, MA, USA
4 Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA

To whom correspondence should be addressed
Li Zhang, Departments of Physiology and Surgery, Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, 800 W. Baltimore Street, Baltimore, MD 21201, USA. Tel.: +1 410 706 8040; Fax: +1 410 706 8121; E-mail: LiZhang@som.umaryland.edu

Received 22 April 2005; Accepted 15 March 2006; Published online 6 April 2006.
Abstract
Migration of activated macrophages is essential for resolution of acute inflammation and the initiation of adaptive immunity. Here, we show that efficient macrophage migration in inflammatory environment depends on Mac-1 recognition of a binary complex consisting of fibrin within the provisional matrix and the protease tPA (tissue-type plasminogen activator). Subsequent neutralization of tPA by its inhibitor PAI-1 enhances binding of the integrin–protease–inhibitor complex to the endocytic receptor LRP (lipoprotein receptor-related protein), triggering a switch from cell adhesion to cell detachment. Genetic inactivation of Mac-1, tPA, PAI-1 or LRP but not the protease uPA abrogates macrophage migration. The defective macrophage migration in PAI-1-deficient mice can be restored by wild-type but not by a mutant PAI-1 that does not interact with LRP. In vitro analysis shows that tPA promotes Mac-1-mediated adhesion, whereas PAI-1 and LRP facilitate its transition to cell retraction. Our results emphasize the importance of ordered transitions both temporally and spatially between individual steps of cell migration, and support a model where efficient migration of inflammatory macrophages depends on cooperation of three physiologically prominent systems (integrins, coagulation and fibrinolysis, and endocytosis).
Keywords: inflammation, integrin Mac-1, LRP, macrophage, migration
Send to a friendEmail link to a friend
PDFDownload PDF
Full textFull text
Next article
Previous article
Table of contents
rights and permissionsRights and permissions
order commercial reprintsReprints
ToC alertRegister for table of contents by email
  Privacy policy Copyright © 2006 by the European Molecular Biology Organization