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Marian Tomasiak - One of the best experts on this subject based on the ideXlab platform.
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asthma is associated with reduced fibrinolytic activity abnormal Clot architecture and decreased Clot Retraction rate
Allergy, 2017Co-Authors: M M Tomasiaklozowska, Tomasz Rusak, Tomasz Misztal, Justyna Branskajanuszewska, Anna Bodzentalukaszyk, Marian TomasiakAbstract:The aim of this study was to assess whether steroid-naive asthma modulates hemostasis. We evaluated the Clot Retraction rate (CRR), fibrinolysis rate (FR), Clot density (CD) (by confocal microscopy), plasma levels of plasminogen activator inhibitor (PAI-1), and factor XIII (FXIII), NO in exhaled breath (FENO), spirometry (FEV1) and eosinophil count (EOS) in 36 patients with allergic, steroid-naive asthma and in 34 healthy controls. We observed significantly (P < 0.001) reduced CRR, FR, and FEV1 and increased FENO, EOS, PAI-1, FXIII, and CD in patients with asthma compared with controls. In patients with asthma, FR negatively correlated with CD, FXIII, PAI-1, FENO, and EOS and positively with FEV1. FXIII positively correlated with CD. Clot Retraction rate negatively correlated with FENO and positively with FEV1 (all P < 0.001). These novel findings suggest that asthma itself is associated with decreased CRR and reduced fibrinolytic potential resulting from alterations in Clot architecture and elevated levels of plasma FXIII and PAI-1.
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reduced Clot Retraction rate and altered platelet energy production in patients with asthma
Journal of Asthma, 2016Co-Authors: M M Tomasiaklozowska, Tomasz Rusak, Tomasz Misztal, Anna Bodzentalukaszyk, Marian TomasiakAbstract:AbstractObjective: Asthma enhances the risk of pulmonary embolism. The mechanism of this phenomenon is unclear. Methods: We evaluated the kinetics of Clot formation, Clot Retraction rate (CRR), Clot volume at 40 min, the rate of lactate production (a marker of aerobic glycolysis in platelets in contracting Clots), blood eosinophil count (EOS), nitric oxide in exhaled breath (FENO), and spirometry (FEV1) in 50 healthy controls and in 81 allergic asthmatics (41 subjects with steroid-naive asthma and 40 with steroid-treated asthma). Results: Thromboelastometry revealed that only steroid-treated asthmatics had slightly activated coagulation. Compared with healthy controls, whole asthmatics demonstrated (p < 0.05) reduced CRR, higher Clot volume at 40 minutes, higher FENO, decreased FEV1, elevated EOS, and augmented lactate production in retracting Clots. Reduced CRR was observed also in the absence of native plasma. In whole study population (asthmatics and healthy controls), CRR positively correlated with sp...
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clinically relevant hocl concentrations reduce Clot Retraction rate via the inhibition of energy production in platelet mitochondria
Free Radical Research, 2014Co-Authors: Tomasz Misztal, Tomasz Rusak, Marian TomasiakAbstract:AbstractUsing porcine blood, we examined the impact of hypochlorite, product of activated inflammatory cells, on Clot Retraction (CR), an important step of hemostasis. We found that, in vitro, HOCl is able to reduce CR rate and enlarge final Clot size in whole blood (t.c. 100 μM), platelet-rich plasma (PRP) threshold concentration (t.c. 50 μM), and an artificial system (washed platelets and fibrinogen) (t.c. 25 nM). Combination of low HOCl and peroxynitrite concentrations resulted in synergistic inhibition of CR by these stressors. Concentrations of HOCl completely inhibiting CR failed to affect the kinetics of coagulation measured in PRP and in platelet-free plasma. Concentrations of HOCl reducing CR rate in PRP augmented production of lactate, inhibited consumption of oxygen by platelets, and decreased total adenosine triphosphate (ATP) content in PRP-derived Clots. In an artificial system, concentrations of HOCl resulting in inhibition of CR (25–100 nM) reduced mitochondrial transmembrane potential and...
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platelet related fibrinolysis resistance in patients suffering from pv impact of Clot Retraction and isovolemic erythrocytapheresis
Thrombosis Research, 2014Co-Authors: Tomasz Rusak, Jaroslaw Piszcz, Tomasz Misztal, Justyna Branskajanuszewska, Marian TomasiakAbstract:Abstract Using patients with polycythemia vera (PV) as an experimental model, we evaluated the impact of Clot Retraction (CR) and architecture of the Clot on fibrinolysis. We studied the kinetics of Clot Retraction and the fibrinolysis rate in whole blood from 48 PV patients and 48 healthy controls. Measurements were performed before and after isovolemic eryhrocytapheresis (ECP). CR was measured by optical method. Clot lysis time (CLT) and maximum Clot firmness (MCF) were measured by thromboelastometry in recalcified blood supplemented with t-PA and tissue factor. Compared with healthy controls, CR rate in PV patients was higher (0.0219 vs. 0.0138; p 0.3). Compared with healthy controls, CLT in PV patients was significantly prolonged (158 min vs. 71 min). Fibrinolysis rate inversely correlated with CR rate (r = -0.566; p
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peroxynitrite may affect Clot Retraction in human blood through the inhibition of platelet mitochondrial energy production
Thrombosis Research, 2014Co-Authors: Tomasz Misztal, Tomasz Rusak, Marian TomasiakAbstract:Abstract Peroxynitrite (ONOO - ) contributes to hemostasis abnormalities associated with inflammatory states by a poorly understood mechanism. Here we show that ONOO - may affect Clot Retraction (CR), an important step in hemostasis, by reducing contractility of human platelets resulting from the inhibition of mitochondrial energy production. Reduced CR may result in thromboembolic and hemorrhage events. The results show that in human blood, in vitro , physiologically relevant ONOO - concentrations reduce Clot Retraction rate and enlarge final Clot size. The stressor was more effective in reconstituted system consisting of washed platelets and fibrinogen, (IC 50 =25nM) than in platelet rich plasma (IC 50 =75μM) or in whole blood (IC 50 =120μM), indicating that its effect depends on the number of targets. Retardation of CR by lower concentrations of ONOO - resulted in reduction of platelet energy production due to impairment of mitochondria but not from tyrosine nitration or inhibition of actin polymerization. In washed platelets nanomolar ONOO - concentrations produced a drop of the mitochondrial transmembrane potential (ΔΨ m ) explaining high sensitivity of CR (a large consumer of platelet energy) to stressor. Thromboelastometry measurements showed that ONOO - may diminish Clot stability and elasticity through the reduction of platelet contractility. Our findings suggest that in humans ONOO - - altered platelet mitochondria represent a new link between inflammation and hemostasis.
Tomasz Rusak - One of the best experts on this subject based on the ideXlab platform.
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the myeloperoxidase product hypochlorous acid reduces thrombus formation under flow and attenuates Clot Retraction and fibrinolysis in human blood
Free Radical Biology and Medicine, 2019Co-Authors: Tomasz Misztal, M M Tomasiaklozowska, Agata Golaszewska, Marta Iwanicka, Natalia Marcinczyk, Agnieszka Leszczynska, Ewa Chabielska, Tomasz RusakAbstract:Abstract Hypochlorite (HOCl), a strong oxidant and antimicrobial agent, has been proposed to be associated with hemostatic abnormalities during inflammatory response. However, its complex impact on hemostasis is not completely understood. In this report we studied the effect of clinically relevant (micromolar) HOCl concentrations on thrombus formation under flow, kinetics of platelet-fibrin Clot formation, its architecture, Retraction, and lysis. We found that HOCl (up to 500 µM) did not affect kinetics of coagulation measured in whole blood. HOCl (500-1000 µM) markedly diminished thrombus formation under flow. Clot Retraction rate was reduced by HOCl dose-dependently (50-500 µM). HOCl (125-500 µM) inhibited fibrinolysis in whole blood and in platelet-depleted plasma, dose-dependently. Activity of plasmin was reduced by HOCl at concentrations started from 500 µM. HOCl (up to 500 µM) did not reduce plasminogen binding to fibrin under flow. HOCl (125-500 µM) modulated architecture of fibrin- and platelet-fibrin Clots towards structures made of thin and densely packed fibers. Exposure of pure fibrinogen to HOCl (10-1000 µM) resulted in formation of dityrosine and was associated with altered fibrin structure derived from such modified fibrinogen. HOCl-altered fibrin net structure was not related with modulation of platelet procoagulant response, thrombin generation, and factor XIII activity. We conclude that, in human blood, clinically relevant HOCl concentrations may inhibit thrombus formation under flow, Clot Retraction and fibrinolysis. Fibrinolysis and Clot Retraction seem to be the most sensitive to HOCl-evoked inhibition. HOCl-modified fibrinogen and altered Clot structure associated with it are likely to be primary sources of attenuated fibrinolysis.
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asthma is associated with reduced fibrinolytic activity abnormal Clot architecture and decreased Clot Retraction rate
Allergy, 2017Co-Authors: M M Tomasiaklozowska, Tomasz Rusak, Tomasz Misztal, Justyna Branskajanuszewska, Anna Bodzentalukaszyk, Marian TomasiakAbstract:The aim of this study was to assess whether steroid-naive asthma modulates hemostasis. We evaluated the Clot Retraction rate (CRR), fibrinolysis rate (FR), Clot density (CD) (by confocal microscopy), plasma levels of plasminogen activator inhibitor (PAI-1), and factor XIII (FXIII), NO in exhaled breath (FENO), spirometry (FEV1) and eosinophil count (EOS) in 36 patients with allergic, steroid-naive asthma and in 34 healthy controls. We observed significantly (P < 0.001) reduced CRR, FR, and FEV1 and increased FENO, EOS, PAI-1, FXIII, and CD in patients with asthma compared with controls. In patients with asthma, FR negatively correlated with CD, FXIII, PAI-1, FENO, and EOS and positively with FEV1. FXIII positively correlated with CD. Clot Retraction rate negatively correlated with FENO and positively with FEV1 (all P < 0.001). These novel findings suggest that asthma itself is associated with decreased CRR and reduced fibrinolytic potential resulting from alterations in Clot architecture and elevated levels of plasma FXIII and PAI-1.
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reduced Clot Retraction rate and altered platelet energy production in patients with asthma
Journal of Asthma, 2016Co-Authors: M M Tomasiaklozowska, Tomasz Rusak, Tomasz Misztal, Anna Bodzentalukaszyk, Marian TomasiakAbstract:AbstractObjective: Asthma enhances the risk of pulmonary embolism. The mechanism of this phenomenon is unclear. Methods: We evaluated the kinetics of Clot formation, Clot Retraction rate (CRR), Clot volume at 40 min, the rate of lactate production (a marker of aerobic glycolysis in platelets in contracting Clots), blood eosinophil count (EOS), nitric oxide in exhaled breath (FENO), and spirometry (FEV1) in 50 healthy controls and in 81 allergic asthmatics (41 subjects with steroid-naive asthma and 40 with steroid-treated asthma). Results: Thromboelastometry revealed that only steroid-treated asthmatics had slightly activated coagulation. Compared with healthy controls, whole asthmatics demonstrated (p < 0.05) reduced CRR, higher Clot volume at 40 minutes, higher FENO, decreased FEV1, elevated EOS, and augmented lactate production in retracting Clots. Reduced CRR was observed also in the absence of native plasma. In whole study population (asthmatics and healthy controls), CRR positively correlated with sp...
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clinically relevant hocl concentrations reduce Clot Retraction rate via the inhibition of energy production in platelet mitochondria
Free Radical Research, 2014Co-Authors: Tomasz Misztal, Tomasz Rusak, Marian TomasiakAbstract:AbstractUsing porcine blood, we examined the impact of hypochlorite, product of activated inflammatory cells, on Clot Retraction (CR), an important step of hemostasis. We found that, in vitro, HOCl is able to reduce CR rate and enlarge final Clot size in whole blood (t.c. 100 μM), platelet-rich plasma (PRP) threshold concentration (t.c. 50 μM), and an artificial system (washed platelets and fibrinogen) (t.c. 25 nM). Combination of low HOCl and peroxynitrite concentrations resulted in synergistic inhibition of CR by these stressors. Concentrations of HOCl completely inhibiting CR failed to affect the kinetics of coagulation measured in PRP and in platelet-free plasma. Concentrations of HOCl reducing CR rate in PRP augmented production of lactate, inhibited consumption of oxygen by platelets, and decreased total adenosine triphosphate (ATP) content in PRP-derived Clots. In an artificial system, concentrations of HOCl resulting in inhibition of CR (25–100 nM) reduced mitochondrial transmembrane potential and...
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platelet related fibrinolysis resistance in patients suffering from pv impact of Clot Retraction and isovolemic erythrocytapheresis
Thrombosis Research, 2014Co-Authors: Tomasz Rusak, Jaroslaw Piszcz, Tomasz Misztal, Justyna Branskajanuszewska, Marian TomasiakAbstract:Abstract Using patients with polycythemia vera (PV) as an experimental model, we evaluated the impact of Clot Retraction (CR) and architecture of the Clot on fibrinolysis. We studied the kinetics of Clot Retraction and the fibrinolysis rate in whole blood from 48 PV patients and 48 healthy controls. Measurements were performed before and after isovolemic eryhrocytapheresis (ECP). CR was measured by optical method. Clot lysis time (CLT) and maximum Clot firmness (MCF) were measured by thromboelastometry in recalcified blood supplemented with t-PA and tissue factor. Compared with healthy controls, CR rate in PV patients was higher (0.0219 vs. 0.0138; p 0.3). Compared with healthy controls, CLT in PV patients was significantly prolonged (158 min vs. 71 min). Fibrinolysis rate inversely correlated with CR rate (r = -0.566; p
Tomasz Misztal - One of the best experts on this subject based on the ideXlab platform.
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the myeloperoxidase product hypochlorous acid reduces thrombus formation under flow and attenuates Clot Retraction and fibrinolysis in human blood
Free Radical Biology and Medicine, 2019Co-Authors: Tomasz Misztal, M M Tomasiaklozowska, Agata Golaszewska, Marta Iwanicka, Natalia Marcinczyk, Agnieszka Leszczynska, Ewa Chabielska, Tomasz RusakAbstract:Abstract Hypochlorite (HOCl), a strong oxidant and antimicrobial agent, has been proposed to be associated with hemostatic abnormalities during inflammatory response. However, its complex impact on hemostasis is not completely understood. In this report we studied the effect of clinically relevant (micromolar) HOCl concentrations on thrombus formation under flow, kinetics of platelet-fibrin Clot formation, its architecture, Retraction, and lysis. We found that HOCl (up to 500 µM) did not affect kinetics of coagulation measured in whole blood. HOCl (500-1000 µM) markedly diminished thrombus formation under flow. Clot Retraction rate was reduced by HOCl dose-dependently (50-500 µM). HOCl (125-500 µM) inhibited fibrinolysis in whole blood and in platelet-depleted plasma, dose-dependently. Activity of plasmin was reduced by HOCl at concentrations started from 500 µM. HOCl (up to 500 µM) did not reduce plasminogen binding to fibrin under flow. HOCl (125-500 µM) modulated architecture of fibrin- and platelet-fibrin Clots towards structures made of thin and densely packed fibers. Exposure of pure fibrinogen to HOCl (10-1000 µM) resulted in formation of dityrosine and was associated with altered fibrin structure derived from such modified fibrinogen. HOCl-altered fibrin net structure was not related with modulation of platelet procoagulant response, thrombin generation, and factor XIII activity. We conclude that, in human blood, clinically relevant HOCl concentrations may inhibit thrombus formation under flow, Clot Retraction and fibrinolysis. Fibrinolysis and Clot Retraction seem to be the most sensitive to HOCl-evoked inhibition. HOCl-modified fibrinogen and altered Clot structure associated with it are likely to be primary sources of attenuated fibrinolysis.
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asthma is associated with reduced fibrinolytic activity abnormal Clot architecture and decreased Clot Retraction rate
Allergy, 2017Co-Authors: M M Tomasiaklozowska, Tomasz Rusak, Tomasz Misztal, Justyna Branskajanuszewska, Anna Bodzentalukaszyk, Marian TomasiakAbstract:The aim of this study was to assess whether steroid-naive asthma modulates hemostasis. We evaluated the Clot Retraction rate (CRR), fibrinolysis rate (FR), Clot density (CD) (by confocal microscopy), plasma levels of plasminogen activator inhibitor (PAI-1), and factor XIII (FXIII), NO in exhaled breath (FENO), spirometry (FEV1) and eosinophil count (EOS) in 36 patients with allergic, steroid-naive asthma and in 34 healthy controls. We observed significantly (P < 0.001) reduced CRR, FR, and FEV1 and increased FENO, EOS, PAI-1, FXIII, and CD in patients with asthma compared with controls. In patients with asthma, FR negatively correlated with CD, FXIII, PAI-1, FENO, and EOS and positively with FEV1. FXIII positively correlated with CD. Clot Retraction rate negatively correlated with FENO and positively with FEV1 (all P < 0.001). These novel findings suggest that asthma itself is associated with decreased CRR and reduced fibrinolytic potential resulting from alterations in Clot architecture and elevated levels of plasma FXIII and PAI-1.
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reduced Clot Retraction rate and altered platelet energy production in patients with asthma
Journal of Asthma, 2016Co-Authors: M M Tomasiaklozowska, Tomasz Rusak, Tomasz Misztal, Anna Bodzentalukaszyk, Marian TomasiakAbstract:AbstractObjective: Asthma enhances the risk of pulmonary embolism. The mechanism of this phenomenon is unclear. Methods: We evaluated the kinetics of Clot formation, Clot Retraction rate (CRR), Clot volume at 40 min, the rate of lactate production (a marker of aerobic glycolysis in platelets in contracting Clots), blood eosinophil count (EOS), nitric oxide in exhaled breath (FENO), and spirometry (FEV1) in 50 healthy controls and in 81 allergic asthmatics (41 subjects with steroid-naive asthma and 40 with steroid-treated asthma). Results: Thromboelastometry revealed that only steroid-treated asthmatics had slightly activated coagulation. Compared with healthy controls, whole asthmatics demonstrated (p < 0.05) reduced CRR, higher Clot volume at 40 minutes, higher FENO, decreased FEV1, elevated EOS, and augmented lactate production in retracting Clots. Reduced CRR was observed also in the absence of native plasma. In whole study population (asthmatics and healthy controls), CRR positively correlated with sp...
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clinically relevant hocl concentrations reduce Clot Retraction rate via the inhibition of energy production in platelet mitochondria
Free Radical Research, 2014Co-Authors: Tomasz Misztal, Tomasz Rusak, Marian TomasiakAbstract:AbstractUsing porcine blood, we examined the impact of hypochlorite, product of activated inflammatory cells, on Clot Retraction (CR), an important step of hemostasis. We found that, in vitro, HOCl is able to reduce CR rate and enlarge final Clot size in whole blood (t.c. 100 μM), platelet-rich plasma (PRP) threshold concentration (t.c. 50 μM), and an artificial system (washed platelets and fibrinogen) (t.c. 25 nM). Combination of low HOCl and peroxynitrite concentrations resulted in synergistic inhibition of CR by these stressors. Concentrations of HOCl completely inhibiting CR failed to affect the kinetics of coagulation measured in PRP and in platelet-free plasma. Concentrations of HOCl reducing CR rate in PRP augmented production of lactate, inhibited consumption of oxygen by platelets, and decreased total adenosine triphosphate (ATP) content in PRP-derived Clots. In an artificial system, concentrations of HOCl resulting in inhibition of CR (25–100 nM) reduced mitochondrial transmembrane potential and...
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platelet related fibrinolysis resistance in patients suffering from pv impact of Clot Retraction and isovolemic erythrocytapheresis
Thrombosis Research, 2014Co-Authors: Tomasz Rusak, Jaroslaw Piszcz, Tomasz Misztal, Justyna Branskajanuszewska, Marian TomasiakAbstract:Abstract Using patients with polycythemia vera (PV) as an experimental model, we evaluated the impact of Clot Retraction (CR) and architecture of the Clot on fibrinolysis. We studied the kinetics of Clot Retraction and the fibrinolysis rate in whole blood from 48 PV patients and 48 healthy controls. Measurements were performed before and after isovolemic eryhrocytapheresis (ECP). CR was measured by optical method. Clot lysis time (CLT) and maximum Clot firmness (MCF) were measured by thromboelastometry in recalcified blood supplemented with t-PA and tissue factor. Compared with healthy controls, CR rate in PV patients was higher (0.0219 vs. 0.0138; p 0.3). Compared with healthy controls, CLT in PV patients was significantly prolonged (158 min vs. 71 min). Fibrinolysis rate inversely correlated with CR rate (r = -0.566; p
Juana Valles - One of the best experts on this subject based on the ideXlab platform.
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serine threonine phosphatases regulate platelet αiibβ3 integrin receptor outside in signaling mechanisms and Clot Retraction
Life Sciences, 2013Co-Authors: Antonio Moscardo, Maria Teresa Santos, Ana Latorre, Isabel Madrid, Juana VallesAbstract:Abstract Aims We studied the role of serine/threonine phosphatases (PSTPs) on α IIb β 3 signaling and the potential selectivity of the level of PSTP inhibition with okadaic acid (OA) on α IIb β 3 signaling for regulation of platelet aggregation and Clot Retraction. Main methods We used washed platelets from normal donors and OA as inhibitor of PSTPs. Clot Retraction was induced by 1 U/mL of thrombin. Reorganized cytoskeleton was isolated from Triton X-100 lysed platelets. The presence of proteins incorporated to the cytoskeleton was assayed by immunoblotting with specific antibodies. Key findings We found that both 100 and 500 nM OA blocked platelet mediated Clot Retraction. In contrast, only 500 nM OA inhibited thrombin-induced inside-out α IIb β 3 activation, platelet aggregation, and cytoskeletal reorganization. Among markers of α IIb β 3 outside-in signaling, 500 nM OA inhibited the incorporation to the cytoskeleton of syk, src, and FAK (Focal Adhesion Kinase) tyrosine kinases and the incorporation and phosphorylation at Tyr 759 of the β 3 chain of α IIb β 3 , while 100 nM OA only inhibited the FAK translocation and its tyrosine phosphorylation. Significance The level of inhibition of PSTPs by low or high OA concentration (33% and 73% inhibition, respectively) in intact whole cells differentially regulates platelet aggregation and integrin signaling, but have a common effect in blocking Clot Retraction. The latter may be associated with the presence of phosphorylated FAK in the cytoskeleton. This study reveals a novel target for anti-platelet treatment to block Clot Retraction without affecting the platelet hemostatic function by a partial inhibition of PSTPs.
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Serine/threonine phosphatases regulate platelet αIIbβ3 integrin receptor outside-in signaling mechanisms and Clot Retraction.
Life Sciences, 2013Co-Authors: Antonio Moscardo, Maria Teresa Santos, Ana Latorre, Isabel Madrid, Juana VallesAbstract:Abstract Aims We studied the role of serine/threonine phosphatases (PSTPs) on α IIb β 3 signaling and the potential selectivity of the level of PSTP inhibition with okadaic acid (OA) on α IIb β 3 signaling for regulation of platelet aggregation and Clot Retraction. Main methods We used washed platelets from normal donors and OA as inhibitor of PSTPs. Clot Retraction was induced by 1 U/mL of thrombin. Reorganized cytoskeleton was isolated from Triton X-100 lysed platelets. The presence of proteins incorporated to the cytoskeleton was assayed by immunoblotting with specific antibodies. Key findings We found that both 100 and 500 nM OA blocked platelet mediated Clot Retraction. In contrast, only 500 nM OA inhibited thrombin-induced inside-out α IIb β 3 activation, platelet aggregation, and cytoskeletal reorganization. Among markers of α IIb β 3 outside-in signaling, 500 nM OA inhibited the incorporation to the cytoskeleton of syk, src, and FAK (Focal Adhesion Kinase) tyrosine kinases and the incorporation and phosphorylation at Tyr 759 of the β 3 chain of α IIb β 3 , while 100 nM OA only inhibited the FAK translocation and its tyrosine phosphorylation. Significance The level of inhibition of PSTPs by low or high OA concentration (33% and 73% inhibition, respectively) in intact whole cells differentially regulates platelet aggregation and integrin signaling, but have a common effect in blocking Clot Retraction. The latter may be associated with the presence of phosphorylated FAK in the cytoskeleton. This study reveals a novel target for anti-platelet treatment to block Clot Retraction without affecting the platelet hemostatic function by a partial inhibition of PSTPs.
Antonio Moscardo - One of the best experts on this subject based on the ideXlab platform.
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serine threonine phosphatases regulate platelet αiibβ3 integrin receptor outside in signaling mechanisms and Clot Retraction
Life Sciences, 2013Co-Authors: Antonio Moscardo, Maria Teresa Santos, Ana Latorre, Isabel Madrid, Juana VallesAbstract:Abstract Aims We studied the role of serine/threonine phosphatases (PSTPs) on α IIb β 3 signaling and the potential selectivity of the level of PSTP inhibition with okadaic acid (OA) on α IIb β 3 signaling for regulation of platelet aggregation and Clot Retraction. Main methods We used washed platelets from normal donors and OA as inhibitor of PSTPs. Clot Retraction was induced by 1 U/mL of thrombin. Reorganized cytoskeleton was isolated from Triton X-100 lysed platelets. The presence of proteins incorporated to the cytoskeleton was assayed by immunoblotting with specific antibodies. Key findings We found that both 100 and 500 nM OA blocked platelet mediated Clot Retraction. In contrast, only 500 nM OA inhibited thrombin-induced inside-out α IIb β 3 activation, platelet aggregation, and cytoskeletal reorganization. Among markers of α IIb β 3 outside-in signaling, 500 nM OA inhibited the incorporation to the cytoskeleton of syk, src, and FAK (Focal Adhesion Kinase) tyrosine kinases and the incorporation and phosphorylation at Tyr 759 of the β 3 chain of α IIb β 3 , while 100 nM OA only inhibited the FAK translocation and its tyrosine phosphorylation. Significance The level of inhibition of PSTPs by low or high OA concentration (33% and 73% inhibition, respectively) in intact whole cells differentially regulates platelet aggregation and integrin signaling, but have a common effect in blocking Clot Retraction. The latter may be associated with the presence of phosphorylated FAK in the cytoskeleton. This study reveals a novel target for anti-platelet treatment to block Clot Retraction without affecting the platelet hemostatic function by a partial inhibition of PSTPs.
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Serine/threonine phosphatases regulate platelet αIIbβ3 integrin receptor outside-in signaling mechanisms and Clot Retraction.
Life Sciences, 2013Co-Authors: Antonio Moscardo, Maria Teresa Santos, Ana Latorre, Isabel Madrid, Juana VallesAbstract:Abstract Aims We studied the role of serine/threonine phosphatases (PSTPs) on α IIb β 3 signaling and the potential selectivity of the level of PSTP inhibition with okadaic acid (OA) on α IIb β 3 signaling for regulation of platelet aggregation and Clot Retraction. Main methods We used washed platelets from normal donors and OA as inhibitor of PSTPs. Clot Retraction was induced by 1 U/mL of thrombin. Reorganized cytoskeleton was isolated from Triton X-100 lysed platelets. The presence of proteins incorporated to the cytoskeleton was assayed by immunoblotting with specific antibodies. Key findings We found that both 100 and 500 nM OA blocked platelet mediated Clot Retraction. In contrast, only 500 nM OA inhibited thrombin-induced inside-out α IIb β 3 activation, platelet aggregation, and cytoskeletal reorganization. Among markers of α IIb β 3 outside-in signaling, 500 nM OA inhibited the incorporation to the cytoskeleton of syk, src, and FAK (Focal Adhesion Kinase) tyrosine kinases and the incorporation and phosphorylation at Tyr 759 of the β 3 chain of α IIb β 3 , while 100 nM OA only inhibited the FAK translocation and its tyrosine phosphorylation. Significance The level of inhibition of PSTPs by low or high OA concentration (33% and 73% inhibition, respectively) in intact whole cells differentially regulates platelet aggregation and integrin signaling, but have a common effect in blocking Clot Retraction. The latter may be associated with the presence of phosphorylated FAK in the cytoskeleton. This study reveals a novel target for anti-platelet treatment to block Clot Retraction without affecting the platelet hemostatic function by a partial inhibition of PSTPs.