194 Subcellular distribution of urokinase-type plasminogen activator and uPA-receptor in neutrophils determined by immunogold labeling and electron microscopy

1997 ◽  
Vol 11 ◽  
pp. 56
Author(s):  
Trine Lindhardt Pedersen ◽  
Thomas Horn ◽  
Niels Ebbe Hansen ◽  
Keld Danø ◽  
Torben Plesner
Keyword(s):  
Electron Microscopy ◽  
Plasminogen Activator ◽  
Subcellular Distribution ◽  
Immunogold Labeling ◽  
Upa Receptor ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator

scholarly journals Plasminogen and Plasminogen Activators Protect against Renal Injury in Crescentic Glomerulonephritis

1997 ◽  
Vol 185 (5) ◽  
pp. 963-968 ◽  
Author(s):  
A. Richard Kitching ◽  
Stephen R. Holdsworth ◽  
Victoria A. Ploplis ◽  
Edward F. Plow ◽  
Désiré Collen ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Crescentic Glomerulonephritis ◽  
Inflammatory Diseases ◽  
Plasminogen Activators ◽  
Matrix Proteins ◽  
Tissue Type ◽  
Glomerular Injury ◽  
Upa Receptor ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator

The plasminogen/plasmin system has the potential to affect the outcome of inflammatory diseases by regulating accumulation of fibrin and other matrix proteins. In human and experimental crescentic glomerulonephritis (GN), fibrin is an important mediator of glomerular injury and renal impairment. Glomerular deposition of matrix proteins is a feature of progressive disease. To study the role of plasminogen and plasminogen activators in the development of inflammatory glomerular injury, GN was induced in mice in which the genes for these proteins had been disrupted by homologous recombination. Deficiency of plasminogen or combined deficiency of tissue type plasminogen activator (tPA) and urokinase type plasminogen activator (uPA) was associated with severe functional and histological exacerbation of glomerular injury. Deficiency of tPA, the predominant plasminogen activator expressed in glomeruli, also exacerbated disease. uPA deficiency reduced glomerular macrophage infiltration and did not significantly exacerbate disease. uPA receptor deficiency did not effect the expression of GN. These studies demonstrate that plasminogen plays an important role in protecting the glomerulus from acute inflammatory injury and that tPA is the major protective plasminogen activator.

scholarly journals The receptor for urokinase type plasminogen activator polarizes expression of the protease to the leading edge of migrating monocytes and promotes degradation of enzyme inhibitor complexes.

1990 ◽  
Vol 111 (2) ◽  
pp. 783-792 ◽  
Author(s):  
A Estreicher ◽  
J Mühlhauser ◽  
J L Carpentier ◽  
L Orci ◽  
J D Vassalli
Keyword(s):  
Cell Surface ◽  
Plasminogen Activator ◽  
Enzyme Inhibitor ◽  
Leading Edge ◽  
Plasminogen Activator Inhibitor ◽  
Upa Receptor ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator ◽  
Monocyte Cell ◽  
Extracellular Proteolysis

Receptor-bound urokinase-type plasminogen activator (uPA) remains associated to the surface of human monocytes for many hours. Monocytes induced to migrate in a chemotactic gradient of f-Met-Leu-Phe rapidly polarize their uPA receptors to the leading front of the cells. Receptor-bound enzyme can be inhibited by plasminogen activator inhibitor 2 (PAI-2), with a kinetics comparable to that determined for the free enzyme, and uPA/PAI-2 complexes can bind to the uPA receptor. In contrast to the active enzyme, the uPA/PAI-2 complex is rapidly cleared from the monocyte cell surface; this involves an initial cleavage of the complex at the cell surface, followed by endocytosis and degradation. These results indicate that the uPA receptor can function both to focus plasmin-mediated extracellular matrix degradation in front of migrating cells, and to target uPA/PAI-2 enzyme/inhibitor complexes for degradation; they suggest that this receptor is a key determinant in the control of uPA-catalyzed extracellular proteolysis.

Leukocyte urokinase plasminogen activator receptor and PSGL1 play a role in endogenous arterial fibrinolysis

2009 ◽  
Vol 102 (12) ◽  
pp. 1212-1218 ◽  
Author(s):  
Xufang Bai ◽  
Jeffrey Weitz ◽  
Peter Gross
Keyword(s):  
Plasminogen Activator ◽  
High Speed ◽  
Wild Type ◽  
Urokinase Plasminogen Activator Receptor ◽  
Activated Platelets ◽  
Upa Receptor ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator ◽  
Plasminogen Activator Receptor ◽  
Deficient Mice

SummaryFibrin is an integral component of arterial thrombi. Using a mouse model of arteriolar thrombosis, high-speed fluorescence microscopy reveals that, within minutes, the fibrin content of thrombi rapidly increases and then decreases.The decrease in fibrin coincides with leukocyte binding to the thrombi, a process mediated by the interaction of leukocyte P-selectin glycoprotein ligand-1 (PSGL-1) with P-selectin on the surface of activated platelets. Because leukocytes possess urokinase-type plasminogen activator (uPA) activity,we used mice deficient in uPA or the uPA receptor (uPAR) to explore the contribution of leukocyte associated uPA to the loss of fibrin from these thrombi. Fibrin loss in both uPA-deficient mice and uPAR-deficient mice was reduced compared with that in wild-type controls.Transfusion of leukocytes from wild-type mice into uPAR-deficient mice restored fibrin loss to levels similar to that in wild-type mice. In contrast, transfusion of leukocytes from mice deficient in uPAR or PSGL-1 did not enhance fibrin loss. Thus, fibrin loss from microarteriolar thrombi is mediated, at least in part, by leukocyte-associated uPA in a process that requires leukocyte uPAR and PSGL-1.

It's not size, it's substance

Blood ◽  
2007 ◽  
Vol 110 (7) ◽  
pp. 2224-2225 ◽  
Author(s):  
Edward F. Plow ◽  
Elzbieta Pluskota
Keyword(s):  
Plasminogen Activator ◽  
Dependent Manner ◽  
Plasminogen Activation ◽  
Upa Receptor ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator

Lacroix and colleagues provide the first evidence that endothelium-derived microparticles provide an efficient surface for plasminogen activation in a urokinase-type plasminogen activator (uPA)–dependent and uPA receptor (uPAR)–dependent manner, and suggest that generated plasmin may influence angiogenesis.

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