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

Parry, Marina; Myles, Timothy; Tschopp, Jürg; Stone, Stuart R.

doi:10.1042/bj3200335

Cited by 58 publications

(65 citation statements)

References 62 publications

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“…It has been reported that plasmin interacts with PAR-1 based on its activity toward a synthetic peptide designed to represent the thrombin cleavage site (25), albeit with an activity that is slower than thrombin by about 10-fold. Kuliopulos et al (26) showed with calcium mobilization studies that plasmin has a low affinity for the traditional thrombin cleavage site on PAR-1 and a higher affinity for a cleavage site that is further downstream; in effect, plasmin is more likely to make PAR-1 refractory to further thrombin stimulation than to stimulate calcium mobilization.…”

Section: Fig 2 Plasmin Desensitizes Par-1 or Par-4 After Long Incubmentioning

confidence: 99%

Plasmin-mediated Activation of Platelets Occurs by Cleavage of Protease-activated Receptor 4

Quinton

Kim

Derian

et al. 2004

Journal of Biological Chemistry

109

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The activation of plasmin from its circulating precursor plasminogen is the mechanism of several clot-busting drugs used to clinically treat patients who have suffered a stroke; however, plasmin thus generated has been shown to activate platelets directly. There has been speculation as to whether plasmin interacts with the protease-activated receptors (PARs) because of its similarity in amino acid specificity with the classic platelet activator thrombin. We have investigated whether plasmin activates platelets via PAR activation through multiple complementary approaches. At concentrations sufficient to induce human platelet aggregation, plasmin released very little calcium compared with that induced by thrombin, the PAR-1 agonist peptide SFLLRN, or the PAR-4 agonist peptide AYPGKF. Stimulation of platelets with plasmin initially failed to desensitize additional stimulation with SFLLRN or AYPGKF, but a prolonged incubation with plasmin desensitized platelets to further stimulation by thrombin. The desensitization of PAR-1 had no effect on plasmininduced platelet aggregation and yielded an aggregation profile that was similar to plasmin in response to a low dose of thrombin. However, PAR-4 desensitization completely eliminated aggregation in response to plasmin. Inclusion of the PAR-1-specific antagonist BMS-200261 inhibited platelet aggregation induced by a low dose of thrombin but not by plasmin. Additionally, mouse platelets naturally devoid of PAR-1 showed a full aggregation response to plasmin in comparison to thrombin. Furthermore, human and mouse platelets treated with a PAR-4 antagonist, as well as platelets isolated from PAR-4 homozygous null mice, failed to aggregate in response to plasmin. Finally, a proteaseresistant recombinant PAR-4 was refractory to activation by plasmin. We conclude that plasmin induces platelet aggregation primarily through slow cleavage of PAR-4.

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Section: Fig 2 Plasmin Desensitizes Par-1 or Par-4 After Long Incubmentioning

confidence: 99%

Plasmin-mediated Activation of Platelets Occurs by Cleavage of Protease-activated Receptor 4

Quinton

Kim

Derian

et al. 2004

Journal of Biological Chemistry

109

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“…Plasmin can bind with high affinity to endothelial cells (Bauer et a!., 1984;Hall et aI., 1991), eliciting functional responses through a specific plasmin receptor, but by cleaving at Arg 41 _Ser 42 it also has the potential to acti vate PAR-I (Parry et a!., 1996). Plasmin is known to affect platelet activation; at high concentrations it in creases, but at lower concentrations it inhibits thrombin induced platelet activation (Kimura et aI., 1996;Kin lough-Rathbone et aI., 1997).…”

mentioning

confidence: 99%

Identification of Thrombin Receptors in Rat Brain Capillary Endothelial Cells

Bartha

Dömötör

Lanza

et al. 2000

J Cereb Blood Flow Metab

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Summary: Both thrombin and plasmin induce contraction of brain endothelial cells, which may increase capillary perme ability thereby leading to disruption of the blood-brain barrier. Identification of thrombin receptors, as well as the influence of plasmin on their activation, in capillary endothelial cells and astrocytes are therefore essential for understanding injury related actions of thrombin in the brain. Using the reverse transcriptase-polymerase chain reaction method, the present study shows that primary cultures of rat brain capillary endo thelial (RBCE) cells and astrocytes derived from rat brain ex press two different thrombin receptors. The first is proteolyti cally activated receptor (PAR)-l, the receptor responsible for the vast majority of the thrombin's cellular activation func tions; the second is PAR-3, a receptor described to be essential for normal responsiveness to thrombin in mouse platelets. In addition to these thrombin receptors, the mRNA (messenger RNA) for PAR-2, a possible trypsin receptor, was also identi fied. Functional significance of thrombin receptors was indi cated by changes in rCa 2 +l; in response to thrombin, as mea sured by FURA-2 fluorescence in RBCE cells. Thrombin as low as 4 nmollL induced an abrupt increase in lCa 2 +1i whereas, Thrombosis is of paramount importance in the patho physiology of ischemic stroke. Thrombogenic and fibri nolytic enzymes accumulating in the occluded vascular segments may play a role in the opening of the blood brain barrier, and the subsequent exposure of cells in the brain to high amounts of thrombin and plasmin is likely to have deleterious effects. Thrombin actions are largely mediated by PAR-I, the first member of the proteolyti-

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“…GrA has been considered as a low-affinity ligand of PAR-1 (Parry et al 1996;Steinhoff et al 2005;Suidan et al 1994). For instance, this protease induced neurite retraction, which was inhibited in the presence of an anti-PAR-1 antibody (Suidan et al 1994).…”

Section: Introductionmentioning

confidence: 99%

Granzyme A and thrombin differentially promote the release of interleukin-8 from alveolar epithelial A549 cells

et al. 2010

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Some of extracellular serine proteases with trypsin-like specificity of cleavage have been known to increase the release of inflammatory mediators from various cell types. For instance, two well-known trypsin-like serine proteases circulating in blood, granzyme A (GrA) and thrombin, have been found to promote interleukin (IL)-8 release from an alveolar epithelial A549 cell line. However, the mechanisms by which the proteases promote IL-8 release from the cells are not fully understood. In the present study, using A549 cells we found that (1) thrombin promoted IL-8 release from the cells via a mechanism partially involving activation of protease-activated receptor-1, a G-protein coupled receptor, whereas a recombinant form of GrA (rGrA) did it via a mechanism that does not involve the receptor activation; that (2) unlike rGrA, thrombin did not cause detachment and microtubule disruption of the cells; and that (3) the release of IL-8 induced by rGrA was inhibited in the presence of taxol, a microtubulestabilizing reagent, whereas that induced by thrombin was not. These findings suggest that rGrA and thrombin promote the release of IL-8 from A549 cells through distinct mechanisms.

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

Cited by 58 publications

References 62 publications

Plasmin-mediated Activation of Platelets Occurs by Cleavage of Protease-activated Receptor 4

Plasmin-mediated Activation of Platelets Occurs by Cleavage of Protease-activated Receptor 4

Identification of Thrombin Receptors in Rat Brain Capillary Endothelial Cells

Granzyme A and thrombin differentially promote the release of interleukin-8 from alveolar epithelial A549 cells

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