Hypochlorous acid (HOCl) activation of neutrophil collagenase requires cathepsin G

1989 ◽  
Vol 27 (3-4) ◽  
pp. 481-484 ◽  
Author(s):  
C. Capodici ◽  
R. A. Berg
1993 ◽  
Vol 39 (6) ◽  
pp. 986-992
Author(s):  
J A Stark ◽  
A R Henderson

Abstract The polymorphonuclear granulocyte, or neutrophil, has been implicated as a mediator of tissue-destructive events because it releases the preformed proteolytic enzymes elastase and cathepsin G, and, as a result of myeloperoxidase action, hypochlorous acid. We show that elastase inactivates and fragments creatine kinase isoenzymes CK-2 and CK-3, and, to a lesser extent, lactate dehydrogenase (LD) isoenzyme LD-1, whereas cathepsin G acts only on CK-2. Both neutrophil enzymes act on LD-3. The course of inactivation was followed by measuring the loss of catalytic activity at 37 degrees C. The evidence for fragmentation was obtained by gel filtration; electrophoresis after sample treatment with sodium dodecyl sulfate and 2-mercaptoethanol was less satisfactory for this purpose. Hypochlorous acid inactivates CK activity by about 75% at concentrations as low as 8 mumol/L and totally at concentrations > 140 mumol/L, whereas LD activity is not affected until concentrations exceed 200 mumol/L. After a myocardial infarction, the number of neutrophils increases; they are triggered and concentrate around damaged myocardial tissue. Our data suggest that neutrophils may inactivate and fragment "cardiac" enzymes released from such damaged tissue.


Inflammation ◽  
1989 ◽  
Vol 13 (3) ◽  
pp. 245-258 ◽  
Author(s):  
Constance Capodici ◽  
Geetha Muthukumaran ◽  
Marie A. Amoruso ◽  
Richard A. Berg

1991 ◽  
Vol 34 (1-2) ◽  
pp. 8-10 ◽  
Author(s):  
C. Capodici ◽  
R. A. Berg

2005 ◽  
Vol 280 (32) ◽  
pp. 29311-29321 ◽  
Author(s):  
Baohai Shao ◽  
Abderrazzaq Belaaouaj ◽  
Christophe L. M. J. Verlinde ◽  
Xiaoyun Fu ◽  
Jay W. Heinecke

1994 ◽  
Vol 71 (04) ◽  
pp. 530-530
Author(s):  
E M Nicolaisen
Keyword(s):  

1992 ◽  
Vol 68 (05) ◽  
pp. 570-576 ◽  
Author(s):  
Mary A Selak

SummaryWe have previously demonstrated that human neutrophil cathepsin G is a strong platelet agonist that binds to a specific receptor. This work describes the effect of neutrophil elastase on cathepsin G-induced platelet responses. While platelets were not activated by high concentrations of neutrophil elastase by itself, elastase enhanced aggregation, secretion and calcium mobilization induced by low concentrations of cathepsin G. Platelet aggregation and secretion were potentiated in a concentration-dependent manner by neutrophil elastase with maximal responses observable at 200 nM. Enhancement was observed when elastase was preincubated with platelets for time intervals of 10–60 s prior to addition of a low concentration of cathepsin G and required catalytically-active elastase since phenylmethanesulphonyl fluoride-inhibited enzyme failed to potentiate cell activation. Neutrophil elastase potentiation of platelet responses induced by low concentrations of cathepsin G was markedly inhibited by creatine phosphate/creatine phosphokinase and/or indomethacin, indicating that the synergism between elastase and cathepsin G required the participation of ADP and thromboxane A2. On the other hand, platelet responses were not attenuated by the PAF antagonist BN 52021, signifying that PAF-acether did not play a role in elastase potentiation. At higher concentrations porcine pancreatic elastase exhibits similar effects to neutrophil elastase, demonstrating that the effect of elastase was not unique to the neutrophil protease. While neutrophil elastase failed to alter the ability of cathepsin G to hydrolyze a synthetic chromogenic substrate, preincubation of platelets with elastase increased the apparent affinity of cathepsin G binding to platelets. In contrast to their effect on cathepsin G-induced platelet responses, neither neutrophil nor pancreatic elasatse potentiated aggregation or dense granule release initiated by ADP, PAF-acether, arachidonic acid or U46619, a thromboxane A2 mimetic. Moreover, unlike its effect on cathepsin G, neutrophil elastase inhibited thrombin-induced responses. The current observations demonstrate that elastase can potentiate platelet responses mediated by low concentrations of cathepsin G, suggesting that both enzymes may function synergistically to activate platelets under conditions where neutrophil degranulation occurs.


1994 ◽  
Vol 72 (01) ◽  
pp. 140-145 ◽  
Author(s):  
Valeri Kolpakov ◽  
Maria Cristina D'Adamo ◽  
Lorena Salvatore ◽  
Concetta Amore ◽  
Alexander Mironov ◽  
...  

SummaryActivated neutrophils may promote thrombus formation by releasing proteases which may activate platelets, impair the fibrinolytic balance and injure the endothelial monolayer.We have investigated the morphological correlates of damage induced by activated neutrophils on the vascular wall, in particular the vascular injury induced by released cathepsin G in both static and dynamic conditions.Human umbilical vein endothelial cells were studied both in a cell culture system and in a model of perfused umbilical veins. At scanning electron microscopy, progressive alterations of the cell monolayer resulted in cell contraction, disruption of the intercellular contacts, formation of gaps and cell detachment.Contraction was associated with shape change of the endothelial cells, that appeared star-like, while the underlying extracellular matrix, a potentially thrombogenic surface, was exposed. Comparable cellular response was observed in an “in vivo” model of perfused rat arterial segment. Interestingly, cathepsin G was active at lower concentrations in perfused vessels than in culture systems. Restoration of blood flow in the arterial segment previously damaged by cathepsin G caused adhesion and spreading of platelets on the surface of the exposed extracellular matrix. The subsequent deposition of a fibrin network among adherent platelets, could be at least partially ascribed to the inhibition by cathepsin G of the vascular fibrinolytic potential.This study supports the suggestion that the release of cathepsin G by activated neutrophils, f.i. during inflammation, may contribute to thrombus formation by inducing extensive vascular damage.


1992 ◽  
Vol 67 (06) ◽  
pp. 660-664 ◽  
Author(s):  
Virgilio Evangelista ◽  
Paola Piccardoni ◽  
Giovanni de Gaetano ◽  
Chiara Cerletti

SummaryDefibrotide is a polydeoxyribonucleotide with antithrombotic effects in experimental animal models. Most of the actions of this drug have been observed in in vivo test models but no effects have been reported in in vitro systems. In this paper we demonstrate that defibrotide interferes with polymorphonuclear leukocyte-induced human platelet activation in vitro. This effect was not related to any direct interaction with polymorphonuclear leukocytes or platelets, but was due to the inhibition of cathepsin G, the main biochemical mediator of this cell-cell cooperation. Since cathepsin G not only induces platelet activation but also affects some endothelial cell functions, the anticathepsin G activity of defibrotide could help to explain the antithrombotic effect of this drug.


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