Human leukocyte cathepsin G and elastase specifically suppress thrombin- induced prostacyclin production in human endothelial cells

Weksler, Babette B.; Jaffe, Eric; Brower, Mark S.; Cole, Olatoun F.

doi:10.1182/blood.v74.5.1627.1627

Cited by 64 publications

(15 citation statements)

References 39 publications

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“…Moreover, the observed specificity constant for TR$) -'! (10% M −" :s −" ), coupled with the observation that high concentrations of cathepsin G can be released locally from neutrophils [23], indicates that this potential inactivation of the receptor might be relevant in certain pathological conditions.…”

Section: Cleavage Of the Thrombin Receptor By Proteases From Neutrophmentioning

confidence: 99%

“…by chymotrypsin, cathepsin G, neutrophil elastase and granzyme B were determined. Neutrophil elastase and cathepsin G are released in high concentrations on activation of neutrophils [23]. Overnight (16 h) incubation of 4 µM TR$) -'!…”

Section: By Proteases With a Preference For Hydrophobic Or Acidic Resmentioning

confidence: 99%

“…Selak [53] has recently proposed that cathepsin G can activate human platelets through the cleavage of its own receptor. However, treatment of endothelial cells with cathepsin G at concentrations achieved in i o inhibits thrombin-induced prostacyclin release and increases in intracellular [Ca# + ] [23], suggesting that cathepsin G cleaves and inactivates the thrombin receptor. Results obtained in the present study and those of Molino et al [54] support the hypothesis that cathepsin G cleaves and inactivates the thrombin receptor.…”

Section: Cleavage Of the Thrombin Receptor By Proteases From Neutrophmentioning

confidence: 99%

“…The response of several cell lines to neutrophil elastase has also been studied in detail [23,46,53,55]. Although platelets are not activated by elastase, it potentiates cathepsin G-induced platelet activation and inhibits thrombin-induced responses in platelets, endothelial and Jurkat T-cells [23,46,53,55]. If elastase cleaves and inactivates the thrombin receptor on these cells, the site of cleavage must be between residue 61 and the first transmembrane domain ; elastase did not cleave between residues 38 and 60.…”

Section: Cleavage Of the Thrombin Receptor By Proteases From Neutrophmentioning

confidence: 99%

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Cleavage of the thrombin receptor: identification of potential activators and inactivators

Parry

Myles

Tschopp

et al. 1996

Biochemical Journal

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The kinetic parameters were determined for the hydrolysis of a peptide based on the activation site of the thrombin receptor (residues 38-60) by thrombin and 12 other proteases. The kcat and Km values for the cleavage of this peptide (TR39-40) by thrombin were 107 s-1 and 1.3 microM; the kcat/Km of TR39-40 is among the highest observed for thrombin. A model is presented that reconciles the parameters for cleavage of the peptide with the concentration dependence of cellular responses to thrombin. Cleavage of TR39-40 was not specific for thrombin. The pancreatic proteases trypsin and chymotrypsin hydrolysed TR39-40 efficiently (kcat/Km > 10(6) M-1.s-1). Whereas trypsin cleaved TR39-40 at the thrombin activation site (Arg41-Ser42), chymotrypsin hydrolysed the peptide after Phe43. This chymotryptic cleavage would result in inactivation of the receptor. The efficient cleavage of TR39-40 by chymotrypsin (kcat/Km approximately 10(6) M-1.s-1) was predominantly due to a low Km value (2.8 microM). The proteases factor Xa, plasmin, plasma kallikrein, activated protein C and granzyme A also hydrolysed TR39-40 at the Arg41-Ser43 bond, but exhibited kcat/Km values that were at least 10(3)-fold lower than that observed with thrombin. Both tissue and urokinase plasminogen activators as well as granzyme B and neutrophil elastase were unable to cleave TR39-60 at appreciable rates. However, neutrophil cathepsin G hydrolysed the receptor peptide after Phe55. Like the chymotryptic cleavage, this cleavage would lead to inactivation of the receptor, but the cathepsin G reaction was markedly less efficient; the kcat/K(m) value was almost four orders of magnitude lower than that for thrombin. In addition to the above cleavage sites, a secondary site for thrombin and other arginine-specific proteases was identified at Arg46, but the cleavage at this site only occurred at very low rates and is unlikely to be significant in vivo.

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Section: Cleavage Of the Thrombin Receptor By Proteases From Neutrophmentioning

confidence: 99%

Section: By Proteases With a Preference For Hydrophobic Or Acidic Resmentioning

confidence: 99%

Section: Cleavage Of the Thrombin Receptor By Proteases From Neutrophmentioning

confidence: 99%

Section: Cleavage Of the Thrombin Receptor By Proteases From Neutrophmentioning

confidence: 99%

See 2 more Smart Citations

Cleavage of the thrombin receptor: identification of potential activators and inactivators

Parry

Myles

Tschopp

et al. 1996

Biochemical Journal

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“…For this kind of damage to be caused, the microcirculation has, by right, to be involved through an increase in permeability and interaction with endothelial receptors 87–93 . These phenomena are more prominent as shear stress decreases and circulation slows down 26,27,35,48,53,65,74,75,82 …”

Section: Phagocytes and Ischemic Heart Diseasementioning

confidence: 99%

Host Tissue Damage by Phagocytes

Ricevuti

1997

Annals of the New York Academy of Sciences

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Evidence continues to accumulate on the importance of neutrophils (PMNs) and phagocytes in the causation of tissue and endothelial injury that frequently accompanies the inflammatory response. Increased production of superoxide anions in combination with decreased endothelial antioxidant activity may contribute to the development of vascular disease including atherosclerosis, vasospasm, diabetic vascular complications, tissue damage in ischemia-reperfusion, and hypotension. Free radicals generated in the vascular wall may act directly on smooth muscle or interact with each other thus producing biologically active endogenous mediators. Derangement of macrophage function may occur in conditions characterized by protein malnutrition, thus leading to failure to develop a specific immunoresponse and to an increase in the production of oxygen intermediate radicals, which may cause tissue damage. A local inflammatory response followed by endothelial cell activation could also facilitate migration of immunocompetent cells into the parenchyma of grafted organs and stimulate dendritic cells in the graft. There is now convincing evidence that excessive and prolonged production of NO contributes to tissue damage in septicemia, ischemia/reperfusion injury, and other inflammatory conditions. There is also increasing evidence that the complement system plays an important role in tissue damage in association with phagocytes, e.g., in ischemia/reperfusion injury, carcinogenesis, and aging. It can therefore be surmised that phagocytic cells may act both as "friends" and as "foes" and that they are important mediators of tissue damage in a variety of conditions.

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Exogenous leukocyte and endogenous elastases can mediate mitogenic activity in pulmonary artery smooth muscle cells by release of extracellular matrix-bound basic fibroblast growth factor

1996

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There is increasing evidence that extracellular matrix (ECM)-degrading proteinases contribute to the process of medial hypertrophy and neointimal proliferation in pulmonary vascular diseases. However, little is known about how proteinases, specifically elastases, induce vascular smooth muscle cell (SMC) hyperplasia. Our objective was to determine whether exogenous human leukocyte elastase (HLE), as well as endogenous vascular elastase, could release basic fibroblast growth factor (bFGF), a potent mitogen stored in the ECM surrounding SMCs. Cultured ovine and porcine pulmonary artery SMC were pre-incubated with [125I]-bFGF. After removal of unbound [125I]-bFGF, administration of HLE (0-1.0 microgram /ml, 1 h) resulted in a concentration-dependent accumulation of [125I]-bFGF in the conditioned medium, mirrored by depletion from the ECM. The serine elastase inhibitor elafin blocked this HLE-mediated action. Assessment by Western immunoblotting further demonstrated that HLE evoked the release of ECM-bound endogenous bFGF. When incubated with serum-starved SMC, conditioned medium from HLE-treated cells stimulated [3H]-thymidine incorporation, a feature neutralized by bFGF antibodies. In addition, SMC exposed to serum treated elastin (STE), previously shown to stimulate endogenous vascular elastase, liberated bioavailable bFGF from ECM stores, as determined by autoradiography, Western immunoblotting, and stimulation of DNA synthesis and SMC proliferation. Chondroitin sulfate, an inhibitor of STE-induced elastase activity, attenuated the release of bFGF. Our studies demonstrate that HLE, secreted by inflammatory cells, and endogenous vascular elastase release matrix-bound bFGF, suggesting a mechanism whereby elastases, through degradation of ECM, induce SMC proliferation associated with progressive vascular disease.

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Human leukocyte cathepsin G and elastase specifically suppress thrombin- induced prostacyclin production in human endothelial cells

Cited by 64 publications

References 39 publications

Cleavage of the thrombin receptor: identification of potential activators and inactivators

Cleavage of the thrombin receptor: identification of potential activators and inactivators

Host Tissue Damage by Phagocytes

Exogenous leukocyte and endogenous elastases can mediate mitogenic activity in pulmonary artery smooth muscle cells by release of extracellular matrix-bound basic fibroblast growth factor

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