Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1996-12-2
pubmed:abstractText
The leukocyte integrin Mac-1 (CD11b/CD18) and the urokinase receptor (uPAR, CD87) mediate complementary functions in myelomonocytic cells. Both receptors promote degradation of fibrin(ogen) and also confer adhesive properties on cells because Mac-1 and uPAR bind fibrin and vitronectin, respectively. Staining of lung biopsy specimens from patients with acute lung injury indicated that fibrin and vitronectin colocalize at exudative sites in which macrophages bearing these receptors accumulate. Because of the parallel roles and physical proximity of Mac-1 and uPAR, the capacity of these receptors to functionally interact was explored. Induction of Mac-1 and uPAR expression on monocytic cell lines by transforming growth factor- beta 1 and 1.25-(OH)2 vitamin D3 conferred urokinase and uPAR-dependent adhesion to vitronectin, which was further promoted by engagement of Mac-1. Vitronectin attachment promoted subsequent Mac-1-mediated fibrinogen degradation threefold to fourfold. In contrast, enhancement of uPAR occupancy by exogenous urokinase or receptor binding fragments thereof inhibited Mac-1 function. Addition of urokinase progressively inhibited Mac-1-mediated fibrinogen binding and degradation (maximal inhibition, 91% +/- 14% and 72% +/- 15%, respectively). Saturation of uPAR with urokinase also inhibited binding of the procoagulant Mac-1 ligand, Factor X. These inhibitory effects of uPAR were reproduced in fresh monocytes, cultured monocytic cells, and in Chinese hamster ovary (CHO) cells transfected with both human Mac-1 and human uPAR. These data show that the procoagulant and fibrinolytic potential of monocytic cells is co-ordinately regulated by ligand binding to both Mac-1 and uPAR and identify uPAR as a regulator of integrin function. Vitronectin-enhanced fibrin(ogen) turnover by Mac-1 may operate as a salvage pathway in the setting of urokinase and plasmin inhibitors to promote clearance of the provisional matrix and subsequent healing.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD18, http://linkedlifedata.com/resource/pubmed/chemical/Calcitriol, http://linkedlifedata.com/resource/pubmed/chemical/Factor X, http://linkedlifedata.com/resource/pubmed/chemical/Fibrin, http://linkedlifedata.com/resource/pubmed/chemical/Fibrinogen, http://linkedlifedata.com/resource/pubmed/chemical/Macromolecular Substances, http://linkedlifedata.com/resource/pubmed/chemical/Macrophage-1 Antigen, http://linkedlifedata.com/resource/pubmed/chemical/Neoplasm Proteins, http://linkedlifedata.com/resource/pubmed/chemical/PLAUR protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Cell Surface, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Urokinase Plasminogen..., http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Transforming Growth Factor beta, http://linkedlifedata.com/resource/pubmed/chemical/Urokinase-Type Plasminogen Activator, http://linkedlifedata.com/resource/pubmed/chemical/Vitronectin
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-4971
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
88
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3185-94
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:8874219-Animals, pubmed-meshheading:8874219-Antigens, CD18, pubmed-meshheading:8874219-Blood Coagulation, pubmed-meshheading:8874219-CHO Cells, pubmed-meshheading:8874219-Calcitriol, pubmed-meshheading:8874219-Cell Adhesion, pubmed-meshheading:8874219-Cricetinae, pubmed-meshheading:8874219-Factor X, pubmed-meshheading:8874219-Fibrin, pubmed-meshheading:8874219-Fibrinogen, pubmed-meshheading:8874219-Fibrinolysis, pubmed-meshheading:8874219-Humans, pubmed-meshheading:8874219-Leukemia, Monocytic, Acute, pubmed-meshheading:8874219-Lung, pubmed-meshheading:8874219-Lung Injury, pubmed-meshheading:8874219-Lymphoma, Large B-Cell, Diffuse, pubmed-meshheading:8874219-Macromolecular Substances, pubmed-meshheading:8874219-Macrophage-1 Antigen, pubmed-meshheading:8874219-Macrophages, pubmed-meshheading:8874219-Monocytes, pubmed-meshheading:8874219-Neoplasm Proteins, pubmed-meshheading:8874219-Receptors, Cell Surface, pubmed-meshheading:8874219-Receptors, Urokinase Plasminogen Activator, pubmed-meshheading:8874219-Recombinant Proteins, pubmed-meshheading:8874219-Transfection, pubmed-meshheading:8874219-Transforming Growth Factor beta, pubmed-meshheading:8874219-Tumor Cells, Cultured, pubmed-meshheading:8874219-Urokinase-Type Plasminogen Activator, pubmed-meshheading:8874219-Vitronectin
pubmed:year
1996
pubmed:articleTitle
Mac-1 (CD11b/CD18) and the urokinase receptor (CD87) form a functional unit on monocytic cells.
pubmed:affiliation
Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't