|
|
||||||||



*
Pulmonary and Critical Care Medicine Division,
Hematology/Oncology Division, Department of Internal Medicine, and
Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI 48109
Leukocytes use urokinase receptors (uPAR; CD87) in adhesion, migration, and proteolysis of matrix proteins. Typically, uPAR clusters at cell-substratum interfaces, at focal adhesions, and at the leading edges of migrating cells. This study was undertaken to determine whether uPAR clustering mediates activation signaling in human polymorphonuclear neutrophils. Cells were labeled with fluo-3/AM to quantitate intracellular Ca2+ ([Ca2+]i) by spectrofluorometry, and uPAR was aggregated by Ab cross-linking. Aggregating uPAR induced a highly reproducible increase in [Ca2+]i (baseline to peak) of 295 ± 37 nM (p = 0.0002). Acutely treating cells with high m.w. urokinase (HMW-uPA; 4000 IU/ml) produced a response of similar magnitude but far shorter duration. Selectively aggregating uPA-occupied uPAR produced smaller increases in [Ca2+]i, but saturating uPAR with HMW-uPA increased the response to approximate that of uPAR cross-linking. Cross-linking uPAR induced rapid and significant increases in membrane expression of CD11b and increased degranulation (release of ß-glucuronidase and lactoferrin) to a significantly greater degree than cross-linking control Abs. The magnitude of degranulation correlated closely with the difference between baseline and peak [Ca2+]i, but was not dependent on the state of uPA occupancy. By contrast, selectively cross-linking uPA-occupied uPAR was capable of directly inducing superoxide release as well as enhancing FMLP-stimulated superoxide release. These results could not be duplicated by preferentially cross-linking unoccupied uPAR. We conclude that uPAR aggregation initiates activation signaling in polymorphonuclear neutrophils through at least two distinct uPA-dependent and uPA-independent pathways, increasing their proinflammatory potency (degranulation and oxidant release) and altering expression of CD11b/CD18 to favor a firmly adherent phenotype.
This article has been cited by other articles:
![]() |
C. Elia, E. Cassol, N. Sidenius, F. Blasi, A. Castagna, G. Poli, and M. Alfano Inhibition of HIV replication by the plasminogen activator is dependent on vitronectin-mediated cell adhesion J. Leukoc. Biol., November 1, 2007; 82(5): 1212 - 1220. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Ortolan, E. V. Tibaldi, B. Ferranti, L. Lavagno, G. Garbarino, R. Notaro, L. Luzzatto, F. Malavasi, and A. Funaro CD157 plays a pivotal role in neutrophil transendothelial migration Blood, December 15, 2006; 108(13): 4214 - 4222. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Brooks, M. E. Bates, R. F. Vrtis, N. N. Jarjour, P. J. Bertics, and J. B. Sedgwick Urokinase-Type Plasminogen Activator Modulates Airway Eosinophil Adhesion in Asthma Am. J. Respir. Cell Mol. Biol., October 1, 2006; 35(4): 503 - 511. [Abstract] [Full Text] [PDF] |
||||
![]() |
S.-H. Kwak, S. Mitra, K. Bdeir, D. Strassheim, J. S. Park, J. Y. Kim, S. Idell, D. Cines, and E. Abraham The kringle domain of urokinase-type plasminogen activator potentiates LPS-induced neutrophil activation through interaction with {alpha}V{beta}3 integrins J. Leukoc. Biol., October 1, 2005; 78(4): 937 - 945. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Funaro, E. Ortolan, B. Ferranti, L. Gargiulo, R. Notaro, L. Luzzatto, and F. Malavasi CD157 is an important mediator of neutrophil adhesion and migration Blood, December 15, 2004; 104(13): 4269 - 4278. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Zhang, X. Cai, J. M. Lopez-Guisa, S. J. Collins, and A. A. Eddy Mitogenic Signaling of Urokinase Receptor-Deficient Kidney Fibroblasts: Actions of an Alternative Urokinase Receptor and LDL Receptor-Related Protein J. Am. Soc. Nephrol., August 1, 2004; 15(8): 2090 - 2102. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. G. Sitrin, D. R. Johnson, P. M. Pan, D. M. Harsh, J. Huang, H. R. Petty, and R. A. Blackwood Lipid Raft Compartmentalization of Urokinase Receptor Signaling in Human Neutrophils Am. J. Respir. Cell Mol. Biol., February 1, 2004; 30(2): 233 - 241. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. D. Liang, K. Bdeir, R. L. Matz, T. Chavakis, and K. T. Preissner Intermolecular Contact Regions in Urokinase Plasminogen Activator Receptor J. Biochem., November 1, 2003; 134(5): 661 - 666. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. L. Coleman and J. L. Benach The Urokinase Receptor Can Be Induced by Borrelia burgdorferi through Receptors of the Innate Immune System Infect. Immun., October 1, 2003; 71(10): 5556 - 5564. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Zhang, H. Kim, X. Cai, J. M. Lopez-Guisa, P. Carmeliet, and A. A. Eddy Urokinase Receptor Modulates Cellular and Angiogenic Responses in Obstructive Nephropathy J. Am. Soc. Nephrol., May 1, 2003; 14(5): 1234 - 1253. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Xia, G. Borland, J. Huang, I. F. Mizukami, H. R. Petty, R. F. Todd III, and G. D. Ross Function of the Lectin Domain of Mac-1/Complement Receptor Type 3 (CD11b/CD18) in Regulating Neutrophil Adhesion J. Immunol., December 1, 2002; 169(11): 6417 - 6426. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Winkler, S. Kastenbauer, U. Koedel, and H. W. Pfister Role of the urokinase plasminogen activator system in patients with bacterial meningitis Neurology, November 12, 2002; 59(9): 1350 - 1355. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Berezov, J. Chen, Q. Liu, H.-T. Zhang, M. I. Greene, and R. Murali Disabling Receptor Ensembles with Rationally Designed Interface Peptidomimetics J. Biol. Chem., July 26, 2002; 277(31): 28330 - 28339. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Stepanova, U. Jerke, V. Sagach, C. Lindschau, R. Dietz, H. Haller, and I. Dumler Urokinase-dependent Human Vascular Smooth Muscle Cell Adhesion Requires Selective Vitronectin Phosphorylation by Ectoprotein Kinase CK2 J. Biol. Chem., March 15, 2002; 277(12): 10265 - 10272. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Yoshitake, Y. Takeda, T. Nitto, and F. Sendo Cross-linking of GPI-80, a possible regulatory molecule of cell adhesion, induces up-regulation of CD11b/CD18 expression on neutrophil surfaces and shedding of L-selectin J. Leukoc. Biol., February 1, 2002; 71(2): 205 - 211. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Resnati, I. Pallavicini, J. M. Wang, J. Oppenheim, C. N. Serhan, M. Romano, and F. Blasi The fibrinolytic receptor for urokinase activates the G protein-coupled chemotactic receptor FPRL1/LXA4R PNAS, January 24, 2002; (2002) 22652999. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. G. Sitrin, P. M. Pan, R. A. Blackwood, J. Huang, and H. R. Petty Cutting Edge: Evidence for a Signaling Partnership Between Urokinase Receptors (CD87) and L-Selectin (CD62L) in Human Polymorphonuclear Neutrophils J. Immunol., April 15, 2001; 166(8): 4822 - 4825. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. D. Liang, T. Chavakis, S. M. Kanse, and K. T. Preissner Ligand Binding Regions in the Receptor for Urokinase-type Plasminogen Activator. STRUCTURAL REQUIREMENTS FOR A MULTIDOMAIN BINDING REGION AND RECEPTOR-RECEPTOR INTERACTION J. Biol. Chem., July 27, 2001; 276(31): 28946 - 28953. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Resnati, I. Pallavicini, J. M. Wang, J. Oppenheim, C. N. Serhan, M. Romano, and F. Blasi The fibrinolytic receptor for urokinase activates the G protein-coupled chemotactic receptor FPRL1/LXA4R PNAS, February 5, 2002; 99(3): 1359 - 1364. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |