Up-regulation of the urokinase-type plasminogen activator receptor by monocyte chemotactic proteins.
The urokinase-type plasminogen activator receptor (uPAR) is a multifunctional molecule involved in migration and adhesion of leukocytes to sites of inflammation. Based on our hypothesis that a chemoattractant can stimulate uPAR expression by its target cell, thereby promoting cell migration, we employed three chemokines [monocyte chemotactic protein (MCP)-1, MCP-2 and MCP-3] as chemoattractants, and examined their effect on uPAR expression in a human monocyte-like cell line, U937. Northern blot analysis demonstrated that all three chemokines tested increased the level of uPAR mRNA in time-dependent and dose-dependent manners. Among them, MCP-3 exhibited the most potent effect. Scatchard analysis showed that incubation with MCP-3 (1 x 10(-8) mol/l) for 16 h resulted in a significant increase in the number of uPAR from (6.8 +/- 0.3) x 10(3) to (10.3 +/- 1.6) x 10(3)/cell, and in a slight increase in the equilibrium dissociation constant, K(d). The effect of anti-uPAR antibodies on MCP-3-induced U937 cell migration across an endothelial cell monolayer and a type I collagen layer was assessed by means of the modified Boyden chamber assay. Although MCP-3 caused a three-fold increase in migration, incubation with an antibody to uPAR markedly abrogated the induced cell migration. These results support our hypothesis and suggest that up-regulation of uPAR in target cells might be an important and common feature of chemoattractants.
Department of Physiology, Miyazaki Medical College, Kiyotake, Miyazaki, Japan.
M
M
Nakayama
E
E
Yoshida
M
M
Sugiki
K
K
Anai
M
M
Maruyama
H
H
Mihara
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002465:Cell Movement / Q000187:drug effects; D018932:Chemokine CCL2 / Q000494:pharmacology*; D054410:Chemokine CCL7; D054412:Chemokine CCL8; D002633:Chemotaxis / Q000187:drug effects; D016207:Cytokines; D004730:Endothelium, Vascular / Q000166:cytology; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D018945:Monocyte Chemoattractant Proteins / Q000494:pharmacology*; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D011956:Receptors, Cell Surface / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D055293:Receptors, Urokinase Plasminogen Activator; D011994:Recombinant Proteins / Q000494:pharmacology; D020298:U937 Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
D000911:Antibodies, Monoclonal; C515450:CCL7 protein, human; C515453:CCL8 protein, human; D018932:Chemokine CCL2; D054410:Chemokine CCL7; D054412:Chemokine CCL8; D016207:Cytokines; D018945:Monocyte Chemoattractant Proteins; D009363:Neoplasm Proteins; C524898:PLAUR protein, human; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D011994:Recombinant Proteins