Correlation between inhibition of cytoskeleton proteolysis and anti-vesiculation effect of calpeptin during A23187-induced activation of human platelets: are vesicles shed by filopod fragmentation?

Bassé, François; Gaffet, Patrick; Bienvenüe, Alain

doi:10.1016/0005-2736(94)90077-9

Cited by 70 publications

(51 citation statements)

References 39 publications

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“…First, it is promoted by the loss of membrane asymmetry described in the previous section (56,57). Second, it also involves hydrolysis of cytoskeletal elements by calcium-dependent proteases (58). Fig.…”

Section: Discussionmentioning

confidence: 99%

Mechanisms by Which Elevated Intracellular Calcium Induces S49 Cell Membranes to Become Susceptible to the Action of Secretory Phospholipase A2

Wilson¹,

Waldrip²,

Nielson³

et al. 1999

Journal of Biological Chemistry

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Exposure of S49 lymphoma cells to exogenous group IIA or V secretory phospholipase A 2 (sPLA 2 ) caused an initial release of fatty acid followed by resistance to further hydrolysis by the enzyme. This refractoriness was overcome by exposing cells to palmitoyl lysolecithin. This effect was specific in terms of lysophospholipid structure. Induction of membrane susceptibility by lysolecithin involved an increase in cytosolic calcium and was duplicated by incubating the cells with calcium ionophores such as ionomycin. Lysolecithin also activated cytosolic phospholipase A 2 (cPLA 2 ). Inhibition of this enzyme attenuated the ability of lysolecithin (but not ionomycin) to induce susceptibility to sPLA 2 . Lysolecithin or ionomycin caused concurrent hydrolysis of both phosphatidylethanolamine and phosphatidylcholine implying that transbilayer movement of phosphatidylethanolamine occurred upon exposure to these agents but that susceptibility is not simply due to exposure of a preferred substrate (i.e. phosphatidylethanolamine) to the enzyme. Microvesicles were apparently released from the cells upon addition of lysolecithin or ionomycin. Both these vesicles and the remnant cell membranes were susceptible to sPLA 2 . Together these data suggest that lysolecithin induces susceptibility through both cPLA 2 -dependent and -independent pathways. Whereas elevated cytosolic calcium was required for both pathways, it was sufficient only for the cPLA 2 -independent pathway. This cPLA 2 -independent pathway involved changes in cell membrane structure associated with transbilayer phospholipid migration and microvesicle release.

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Section: Discussionmentioning

confidence: 99%

Mechanisms by Which Elevated Intracellular Calcium Induces S49 Cell Membranes to Become Susceptible to the Action of Secretory Phospholipase A2

Wilson¹,

Waldrip²,

Nielson³

et al. 1999

Journal of Biological Chemistry

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“…17,18 In addition to the loss of membrane asymmetry, activation of gelsolin and calpain causes is alteration of the platelet actin cytoskeleton and a change in platelet shape, which in itself produces PMV. 19,20 However, PMV are still produced when calpain is inhibited. 21 There are consequentially multiple pathways to PMV production, and disabling one pathway may still allow PMV to be shed.…”

Section: Production Of Pmvmentioning

confidence: 99%

Platelet Microvesicles (Microparticles) in Cardiac Surgery

Tempo

Englyst

Holloway

et al. 2016

Journal of Cardiothoracic and Vascular Anesthesia

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“…thrombin-stimulated platelets Calpeptin has been largely used as a cell permeant specific inhibitor of calpains in platelets at concentrations between 10 and 200 ug/ml [5,8,11]. Since PtdIns(3,4)P 2 synthesis is dependent on aggregation triggered by thrombin stimulation of platelets, we first checked the effects on platelet aggregation and secretion of pretreatment by calpeptin.…”

Section: Calpeptin Inhibition Of Ptdins(34)pi Synthesis Inmentioning

confidence: 99%

“…E-mail: racaud@purpan.inserm.fr Abbreviations: PtdIns(3,4)P2, phosphatidylinositol 3',4'-tephosphate; Ptdlns 3-kinase, phosphatidylinositol 3-kinase; DMSO, dimethylsulfoxide; SH, src homology; HPLC, high performance liquid chromatography integrin has been recently described in thrombin-stimulated platelets [9]. Calpains have been involved in the shedding of procoagulant membrane vesicles and bloating of filopod surfaces in stimulated platelets [10,11], two processes which are closely related to intracellular cytoskeletal reorganization.…”

Section: Introductionmentioning

confidence: 99%

Calpains are involved in phosphatidylinositol 3′,4′‐bisphosphate synthesis dependent on the α_IIbβ₃ integrin engagement in thrombin‐stimulated platelets

et al. 1997

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In thrombin-stimulated platelets (XiibP3 integrin engagement triggers both phosphatidylinositol 3',4'-6wphosphate synthesis and calpain activation. We checked the possible involvement of calpains in phosphatidylinositol 3-kinase signalling pathway using a cell permeant specific inhibitor of calpains, calpeptin. In conditions where thrombin-induced platelet aggregation and secretion were not impaired, we found a dosedependent inhibition of phosphatidylinositol 3,4-6wphosphate synthesis by calpeptin from 50 jig/ml. Moreover, pretreatment of platelets by both calpeptin and the peptide RGDS, an inhibitor of fibrinogen binding to activated an b p 3 integrin, did not induce additive effects on phosphatidylinositol 3,4-/>/vphosphate inhibition. Finally, the p85 regulatory subunit of phosphatidylinositol 3-kinase was still translocated to the cytoskeleton in calpeptintreated platelets. These data indicate that calpains are involved in the regulation of a 1Ib p 3 integrin-dependent phosphatidylinositol 3-kinase signalling pathway.

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Correlation between inhibition of cytoskeleton proteolysis and anti-vesiculation effect of calpeptin during A23187-induced activation of human platelets: are vesicles shed by filopod fragmentation?

Cited by 70 publications

References 39 publications

Mechanisms by Which Elevated Intracellular Calcium Induces S49 Cell Membranes to Become Susceptible to the Action of Secretory Phospholipase A2

Mechanisms by Which Elevated Intracellular Calcium Induces S49 Cell Membranes to Become Susceptible to the Action of Secretory Phospholipase A2

Platelet Microvesicles (Microparticles) in Cardiac Surgery

Calpains are involved in phosphatidylinositol 3′,4′‐bisphosphate synthesis dependent on the α_IIbβ₃ integrin engagement in thrombin‐stimulated platelets

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Correlation between inhibition of cytoskeleton proteolysis and anti-vesiculation effect of calpeptin during A23187-induced activation of human platelets: are vesicles shed by filopod fragmentation?

Cited by 70 publications

References 39 publications

Mechanisms by Which Elevated Intracellular Calcium Induces S49 Cell Membranes to Become Susceptible to the Action of Secretory Phospholipase A2

Mechanisms by Which Elevated Intracellular Calcium Induces S49 Cell Membranes to Become Susceptible to the Action of Secretory Phospholipase A2

Platelet Microvesicles (Microparticles) in Cardiac Surgery

Calpains are involved in phosphatidylinositol 3′,4′‐bisphosphate synthesis dependent on the αIIbβ3 integrin engagement in thrombin‐stimulated platelets

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Product

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About

Calpains are involved in phosphatidylinositol 3′,4′‐bisphosphate synthesis dependent on the α_IIbβ₃ integrin engagement in thrombin‐stimulated platelets