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1.
J Pharmacol Sci ; 144(1): 43-51, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32653340

RESUMO

Platelet activation is the primary cause of thrombosis. The P2X7 receptor (P2X7R) is a therapeutic target of thrombosis. However, it is still unknown whether P2X7R activation affects platelet thrombus. Our molecular docking results showed that entecavir as a P2X7R antagonist interacted perfectly with the human P2X7R (hP2X7R) in silico simulation studies. Furthermore, our experimental data revealed that entecavir could act as a P2X7R antagonist to exert cytoprotective effects against platelet activation via protecting mitochondrial function, improving lipid peroxidation and increasing antioxidant activity. Correlated with this, entecavir inhibited platelet aggregation, dense-granule secretion, P-selectin expression, integrin activation and Ca2+ increase. In experimental mouse model, entecavir could significantly inhibit arteriovenous thrombosis and prolong the bleeding time. Furthermore, we found that entecavir had no significant effect on prothrombin time (PT), activated partial thrombin time (APTT), thrombin time (TT), fibrinogen (FIB), mean platelet volume (MPV) and platelet counts (PLT). This study demonstrates that entecavir markedly prevents platelet activation and thrombosis through inhibiting P2X7R without affecting coagulation system. Therefore, entecavir may be a potential candidate for treating thrombosis disease.


Assuntos
Guanina/análogos & derivados , Ativação Plaquetária/efeitos dos fármacos , Antagonistas do Receptor Purinérgico P2X/farmacologia , Antagonistas do Receptor Purinérgico P2X/uso terapêutico , Receptores Purinérgicos P2X7 , Trombose/prevenção & controle , Animais , Antioxidantes , Tempo de Sangramento , Coagulação Sanguínea/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , Modelos Animais de Doenças , Guanina/farmacologia , Guanina/uso terapêutico , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , Agregação Plaquetária/efeitos dos fármacos , Trombose/sangue
2.
Stroke Vasc Neurol ; 5(2): 185-197, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32606086

RESUMO

Arterial thrombosis is in part contributed by excessive platelet aggregation, which can lead to blood clotting and subsequent heart attack and stroke. Platelets are sensitive to the haemodynamic environment. Rapid haemodynamcis and disturbed blood flow, which occur in vessels with growing thrombi and atherosclerotic plaques or is caused by medical device implantation and intervention, promotes platelet aggregation and thrombus formation. In such situations, conventional antiplatelet drugs often have suboptimal efficacy and a serious side effect of excessive bleeding. Investigating the mechanisms of platelet biomechanical activation provides insights distinct from the classic views of agonist-stimulated platelet thrombus formation. In this work, we review the recent discoveries underlying haemodynamic force-reinforced platelet binding and mechanosensing primarily mediated by three platelet receptors: glycoprotein Ib (GPIb), glycoprotein IIb/IIIa (GPIIb/IIIa) and glycoprotein VI (GPVI), and their implications for development of antithrombotic 'mechano-medicine' .


Assuntos
Arteriopatias Oclusivas/tratamento farmacológico , Coagulação Sanguínea/efeitos dos fármacos , Plaquetas/efeitos dos fármacos , Fibrinolíticos/uso terapêutico , Hemodinâmica , Mecanotransdução Celular/efeitos dos fármacos , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação de Plaquetas/uso terapêutico , Trombose/tratamento farmacológico , Animais , Arteriopatias Oclusivas/sangue , Arteriopatias Oclusivas/fisiopatologia , Plaquetas/metabolismo , Fibrinolíticos/efeitos adversos , Humanos , Terapia de Alvo Molecular , Inibidores da Agregação de Plaquetas/efeitos adversos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Complexo Glicoproteico GPIb-IX de Plaquetas/antagonistas & inibidores , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Glicoproteínas da Membrana de Plaquetas/antagonistas & inibidores , Glicoproteínas da Membrana de Plaquetas/metabolismo , Estresse Mecânico , Trombose/sangue , Trombose/diagnóstico
4.
PLoS One ; 15(6): e0234039, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555710

RESUMO

Sepsis is characterized by organ dysfunction due to a dysregulated immune response to infection. Currently, no effective treatment for sepsis exists. Platelets are recognized as mediators of the immune response and may be a potential therapeutic target for the treatment of sepsis. We previously demonstrated that NLRP3 inflammasome activation in sepsis-induced activated platelets was associated with multi-organ injury in the cecal-ligation puncture (CLP) rat model of sepsis. In this study, we tested the hypothesis that inhibition of NLRP3 would inhibit platelet activation and attenuate multi-organ injury in the CLP rat. CLP (n = 10) or Sham (n = 10) surgery were performed in male and female Sprague-Dawley rats. A subset of CLP rats were treated with MCC950 (50mg/kg/d), a specific NLRP3 inhibitor (CLP+MCC950, n = 10). At 72 hrs. post-CLP, blood and organs were harvested for analysis of platelet activation, NLRP3 activation, inflammation and end organ damage. Platelet activation increased from 8±0.8% in Sham to 16±1% in CLP, and was reduced to 9±1% in CLP+M rats (p<0.05). NLRP3 activation was also increased in platelets of CLP vs Sham. NLRP3 expression was unchanged in kidney and lung after CLP, but Caspase 1 expression and IL-1ß were increased. MCC950 treatment attenuated NLRP3 activation in platelets. Plasma, kidney, and lung levels of NLRP3 inflammasome associated cytokines, IL-1ß and IL-18, were significantly increased in CLP compared to Sham rats. Inhibition of NLRP3 normalized cytokine levels. Glomerular injury, pulmonary edema, and endothelial dysfunction markers were increased in CLP rats vs Sham. MCC950 treatment significantly decreased renal and pulmonary injury and endothelial dysfunction in CLP+M. Our results demonstrate a role for NLRP3 in contributing to platelet activation and multi-organ injury in sepsis.


Assuntos
Ceco/cirurgia , Inflamassomos/antagonistas & inibidores , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Ativação Plaquetária/efeitos dos fármacos , Punções/efeitos adversos , Sepse/tratamento farmacológico , Sepse/fisiopatologia , Animais , Caspase 1/metabolismo , Citocinas/metabolismo , Endotélio/efeitos dos fármacos , Endotélio/metabolismo , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/fisiopatologia , Ligadura/efeitos adversos , Masculino , Permeabilidade/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica/efeitos dos fármacos , Sepse/metabolismo
5.
Thromb Haemost ; 120(5): 776-792, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32369849

RESUMO

BACKGROUND: Implantable cardiovascular therapeutic devices, while hemodynamically effective, remain limited by thrombosis. A driver of device-associated thrombosis is shear-mediated platelet activation (SMPA). Underlying mechanisms of SMPA, as well as useful biomarkers able to detect and discriminate mechanical versus biochemical platelet activation, are poorly defined. We hypothesized that SMPA induces a differing pattern of biomarkers compared with biochemical agonists. METHODS: Gel-filtered human platelets were subjected to mechanical activation via either uniform constant or dynamic shear; or to biochemical activation by adenosine diphosphate (ADP), thrombin receptor-activating peptide 6 (TRAP-6), thrombin, collagen, epinephrine, or arachidonic acid. Markers of platelet activation (P-selectin, integrin αIIbß3 activation) and apoptosis (mitochondrial membrane potential, caspase 3 activation, and phosphatidylserine externalization [PSE]) were examined using flow cytometry. Platelet procoagulant activity was detected by chromogenic assay measuring thrombin generation. Contribution of platelet calcium flux in SMPA was tested employing calcium chelators, ethylenediaminetetraacetic acid (EDTA), and BAPTA-AM. RESULTS: Platelet exposure to continuous shear stress, but not biochemical agonists, resulted in a dramatic increase of PSE and procoagulant activity, while no integrin αIIbß3 activation occurred, and P-selectin levels remained barely elevated. SMPA was associated with dissipation of mitochondrial membrane potential, but no caspase 3 activation was observed. Shear-mediated PSE was significantly decreased by chelation of extracellular calcium with EDTA, while intracellular calcium depletion with BAPTA-AM had no significant effect. In contrast, biochemical agonists ADP, TRAP-6, arachidonic acid, and thrombin were potent inducers of αIIbß3 activation and/or P-selectin exposure. This differing pattern of biomarkers seen for SMPA for continuous uniform shear was replicated in platelets exposed to dynamic shear stress via circulation through a ventricular assist device-propelled circulatory loop. CONCLUSION: Elevated shear stress, but not biochemical agonists, induces a differing pattern of platelet biomarkers-with enhanced PSE and thrombin generation on the platelet surface. This differential biomarker phenotype of SMPA offers the potential for early detection and discrimination from that mediated by biochemical agonists.


Assuntos
Plaquetas/efeitos dos fármacos , Sinalização do Cálcio/efeitos dos fármacos , Mecanotransdução Celular , Ativação Plaquetária/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Biomarcadores/sangue , Coagulação Sanguínea/efeitos dos fármacos , Plaquetas/metabolismo , Plaquetas/patologia , Caspase 3/sangue , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Selectina-P/sangue , Fosfatidilserinas/sangue , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Estresse Mecânico
6.
J Biomed Sci ; 27(1): 60, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32375785

RESUMO

BACKGROUND: Columbianadin (CBN) is one of the main coumarin constituents isolated from Angelica pubescens. The pharmacological value of CBN is well demonstrated, especially in the prevention of several cancers and analgesic activity. A striking therapeutic target for arterial thrombosis is inhibition of platelet activation because platelet activation significantly contributes to these diseases. The current study examined the influence of CBN on human platelet activation in vitro and vascular thrombotic formation in vivo. METHODS: Aggregometry, immunoblotting, immunoprecipitation, confocal microscopic analysis, fibrin clot retraction, and thrombogenic animals were used in this study. RESULTS: CBN markedly inhibited platelet aggregation in washed human platelets stimulated only by collagen, but was not effective in platelets stimulated by other agonists such as thrombin, arachidonic acid, and U46619. CBN evidently inhibited ATP release, intracellular ([Ca2+]i) mobilization, and P-selectin expression. It also inhibited the phosphorylation of phospholipase C (PLC)γ2, protein kinase C (PKC), Akt (protein kinase B), and mitogen-activated protein kinases (MAPKs; extracellular signal-regulated kinase [ERK] 1/2 and c-Jun N-terminal kinase [JNK] 1/2, but not p38 MAPK) in collagen-activated platelets. Neither SQ22536, an adenylate cyclase inhibitor, nor ODQ, a guanylate cyclase inhibitor, reversed the CBN-mediated inhibition of platelet aggregation. CBN had no significant effect in triggering vasodilator-stimulated phosphoprotein phosphorylation. Moreover, it markedly hindered integrin αIIbß3 activation by interfering with the binding of PAC-1; nevertheless, it had no influences on integrin αIIbß3-mediated outside-in signaling such as adhesion number and spreading area of platelets on immobilized fibrinogen as well as thrombin-stimulated fibrin clot retraction. Additionally, CBN did not attenuate FITC-triflavin binding or phosphorylation of proteins, such as integrin ß3, Src, and focal adhesion kinase, in platelets spreading on immobilized fibrinogen. In experimental mice, CBN increased the occlusion time of thrombotic platelet plug formation. CONCLUSION: This study demonstrated that CBN exhibits an exceptional activity against platelet activation through inhibition of the PLCγ2-PKC cascade, subsequently suppressing the activation of Akt and ERKs/JNKs and influencing platelet aggregation. Consequently, this work provides solid evidence and considers that CBN has the potential to serve as a therapeutic agent for the treatment of thromboembolic disorders.


Assuntos
Cumarínicos/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Substâncias Protetoras/farmacologia , Transdução de Sinais/efeitos dos fármacos , Trombose/tratamento farmacológico , Animais , Humanos , Camundongos
7.
Cardiovasc Diabetol ; 19(1): 46, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32264868

RESUMO

BACKGROUND: The clear evidence of cardiovascular benefits in cardiovascular outcome trials of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in type 2 diabetes might suggest an effect on atherosclerotic plaque vulnerability and/or thrombosis, in which myeloid angiogenic cells (MAC) and platelets (PLT) are implicated. We tested the effects of SGLT2i on inflammation and oxidant stress in a model of stearic acid (SA)-induced lipotoxicity in MAC and on PLT activation. The possible involvement of the Na+/H+ exchanger (NHE) was also explored. METHOD: MAC and PLT were isolated from peripheral blood of healthy subjects and incubated with/without SGLT2i [empagliflozin (EMPA) and dapagliflozin (DAPA) 1-100 µM] to assess their effects on SA (100 µM)-induced readouts of inflammation, oxidant stress and apoptosis in MAC and on expression of PLT activation markers by flow-cytometry after ADP-stimulation. Potential NHE involvement was tested with amiloride (aspecific NHE inhibitor) or cariporide (NHE1 inhibitor). Differences among culture conditions were identified using one-way ANOVA or Friedman test. RESULTS: NHE isoforms (1,5-9), but not SGLT2 expression, were expressed in MAC and PLT. EMPA and DAPA (100 µM) significantly reduced SA-induced inflammation (IL1ß, TNFα, MCP1), oxidant stress (SOD2, TXN, HO1), but not apoptosis in MAC. EMPA and DAPA (both 1 µM) reduced PLT activation (CD62p and PAC1 expression). SGLT2i effects were mimicked by amiloride, and only partially by cariporide, in MAC, and by both inhibitors in PLT. CONCLUSIONS: EMPA and DAPA ameliorated lipotoxic damage in stearate-treated MAC, and reduced ADP-stimulated PLT activation, potentially via NHE-inhibition, thereby pointing to plaque stabilization and/or thrombosis inhibition as potential mechanism(s) involved in SGLT2i-mediated cardiovascular protection.


Assuntos
Difosfato de Adenosina/farmacologia , Compostos Benzidrílicos/farmacologia , Plaquetas/efeitos dos fármacos , Células Progenitoras Endoteliais/efeitos dos fármacos , Glucosídeos/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Transportador 2 de Glucose-Sódio/metabolismo , Ácidos Esteáricos/toxicidade , Apoptose/efeitos dos fármacos , Plaquetas/metabolismo , Plaquetas/patologia , Células Cultivadas , Células Progenitoras Endoteliais/metabolismo , Células Progenitoras Endoteliais/patologia , Humanos , Mediadores da Inflamação/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais , Trocadores de Sódio-Hidrogênio/metabolismo
9.
Cardiovasc Ther ; 2020: 8703627, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32284734

RESUMO

Antiplatelet therapy is the mainstay of treatment and secondary prevention of cardiovascular disease (CVD), including acute coronary syndrome (ACS), transient ischemic attack (TIA) or minor stroke, and peripheral artery disease (PAD). The P2Y12 inhibitors, of which clopidogrel was the first, play an integral role in antiplatelet therapy and therefore in the treatment and secondary prevention of CVD. This review discusses the available evidence concerning antiplatelet therapy in patients with CVD, with a focus on the role of clopidogrel. In combination with aspirin, clopidogrel is often used as part of dual antiplatelet therapy (DAPT) for the secondary prevention of ACS. Although newer, more potent P2Y12 inhibitors (prasugrel and ticagrelor) show a greater reduction in ischemic risk compared with clopidogrel in randomized trials of ACS patients, these newer P2Y12 inhibitors are often associated with an increased risk of bleeding. Deescalation of DAPT by switching from prasugrel or ticagrelor to clopidogrel may be required in some patients with ACS. Furthermore, real-world studies of ACS patients have not confirmed the benefits of the newer P2Y12 inhibitors over clopidogrel. In patients with very high-risk TIA or stroke, short-term DAPT with clopidogrel plus aspirin for 21-28 days, followed by clopidogrel monotherapy for up to 90 days, is recommended. Clopidogrel monotherapy may also be used in patients with symptomatic PAD. In conclusion, there is strong evidence supporting the use of clopidogrel antiplatelet therapy in several clinical settings, which emphasizes the importance of this medication in clinical practice.


Assuntos
Plaquetas/efeitos dos fármacos , Doenças Cardiovasculares/tratamento farmacológico , Clopidogrel/uso terapêutico , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação de Plaquetas/uso terapêutico , Plaquetas/metabolismo , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/diagnóstico , Clopidogrel/efeitos adversos , Hemorragia/induzido quimicamente , Humanos , Inibidores da Agregação de Plaquetas/efeitos adversos , Medição de Risco , Fatores de Risco , Prevenção Secundária , Resultado do Tratamento
10.
Adv Clin Chem ; 95: 219-243, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32122524

RESUMO

The main function of blood platelets is to form hemostatic plugs and enable thrombosis. These properties, however, can be greatly influenced by dietary components which may inhibit certain steps of platelet activation, including platelet aggregation. Such inhibition can play a role in the prophylaxis and treatment of cardiovascular diseases associated with blood platelet hyperactivation. In fact, plant and fish oils have been identified and specifically used for this purpose. Numerous in vivo and in vitro experiments have explored the potential use of these oils to inhibit platelet activation as well as their role in reducing oxidative stress and blood pressure, and lowering triglyceride and cholesterol. This chapter presents and compares the anti-platelet effects of fish and plant oils and their constituents, especially fatty acids. Studies on healthy subjects and patients with various cardiovascular diseases are also examined. Findings indicate that both fish and plant oils contain protective components with anti-platelet activity having clearly defined mechanisms of action. Although both are excellent sources of omega fatty acids and vitamins, plant oils contain components with cardioprotective benefit in hypercholesterolemics, i.e., phytosterols. Plant oils may hence play a key role in strategies for preventing and treating cardiovascular diseases associated with platelet hyperactivation. Further studies are clearly needed to determine the precise dose of these components needed for effective prophylaxis and treatment.


Assuntos
Plaquetas/efeitos dos fármacos , Cardiotônicos/farmacologia , Doenças Cardiovasculares/tratamento farmacológico , Óleos Vegetais/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Animais , Humanos
11.
Int J Nanomedicine ; 15: 1759-1770, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32214809

RESUMO

Background: There have been many recent reports of molecular probes for thrombi but with unsatisfactory in vivo targeting effects, which could be related to the blood flow velocity in vivo. Therefore, it is worth explaining the relationship between the targeting effect and the blood flow velocity. Methods and Materials: In this study, we constructed a platelet-targeting nanoparticle (NP) based on EWVDV for targeting P-selectin combined with the phase transition material perfluorohexane and India ink to achieve the multimodal imaging of thrombi. We studied the targeting effect of the NPs for rabbit blood thrombi under different flow velocities simulating blood flow velocities in vivo. Results: The results show the successful fabrication of NPs with the ability to undergo a phase transition via low-intensity focused ultrasound irradiation to achieve ultrasound imaging and with a high binding affinity for activated platelets. In vitro, low flow velocities (20 cm/s) hardly affected the targeting effect of the NPs, while moderate flow velocities (40 cm/s) reduced the number of NPs that target thrombi by 52.6% comparing to static fluid (0 cm/s). High flow velocities (60 cm/s) greatly reduced the targeting effect of the NPs by 83.5%. Conclusion: These results can serve as a reference for the design of NPs targeting thrombi at different sites and in different blood vessel types according to the blood flow velocity, thereby establishing a foundation for in vivo experiments.


Assuntos
Plaquetas/efeitos dos fármacos , Imagem Multimodal/métodos , Nanopartículas/administração & dosagem , Trombose/diagnóstico por imagem , Animais , Velocidade do Fluxo Sanguíneo , Carbono/química , Fluorcarbonetos/química , Nanopartículas/química , Selectina-P/metabolismo , Ativação Plaquetária/efeitos dos fármacos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Coelhos , Trombose/sangue , Ultrassonografia
12.
Toxicol Appl Pharmacol ; 391: 114912, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-32014540

RESUMO

Arsenic, an environmental contaminant in drinking water worldwide is well-established to increase cardiovascular diseases (CVDs) in humans. Of these, thrombotic events represent a major adverse effect associated with arsenic exposure, for which an abundance of epidemiological evidence exists. Platelet aggregation constitutes a pivotal step in thrombosis but arsenic alone doesn't induce aggregation and the mechanism underlying arsenic-induced thrombosis still remains unclear. Here we demonstrated that arsenic induces morphological changes of platelets, i.e., contraction and pseudopod projection, the primal events of platelet activation, which can increase platelet reactivity. Arsenite induced prominent platelet shape changes in a dose-dependent manner in freshly isolated human platelets. Of note, arsenite suppressed focal adhesion kinase (FAK) activity, which in turn activated RhoA, leading to altered actin assembly through LIMK activation, and subsequent cofilin inactivation. Arsenic-induced platelet shape change appeared to increase the sensitivity to thrombin and ADP-induced aggregation. Supporting this, latrunculin A, an inhibitor of actin-dynamics abolished it. Taken together, we demonstrated that arsenic induces cytoskeletal changes and shape changes of platelets through FAK-mediated alteration of actin dynamics, which renders platelets reactive to activating stimuli, ultimately contributing to increased thrombosis.


Assuntos
Actinas/metabolismo , Arsenitos/toxicidade , Plaquetas/patologia , Plaquetas/ultraestrutura , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Ativação Plaquetária/efeitos dos fármacos , Compostos de Sódio/toxicidade , Difosfato de Adenosina/farmacologia , Adolescente , Adulto , Humanos , Técnicas In Vitro , Quinases Lim/antagonistas & inibidores , Masculino , Selectina-P/biossíntese , Agregação Plaquetária/efeitos dos fármacos , Adulto Jovem , Proteína rhoA de Ligação ao GTP
13.
Transfusion ; 60(4): 713-723, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32108957

RESUMO

BACKGROUND: Transfusion-related acute lung injury (TRALI) is a severe pulmonary reaction due to blood transfusions. The pathophysiology of this complication is still not widely elucidated by the scientific community, especially regarding the direct role of blood platelets within the cellular mechanism responsible for the development of TRALI. STUDY DESIGN AND METHODS: In this study, a mouse model was used to induce the development of antibody-mediated acute lung injury through injections of lipopolysaccharide and an anti-major histocompatibility complex Class I antibody. BALB/c mice were pretreated with an anti-GPIbα antibody, which induces platelet depletion, or ML354, a protease receptor 4 pathway inhibitor, 30 minutes before TRALI induction. RESULTS: Depletion of platelets before TRALI induction appeared to reduce the severity of TRALI without completely inhibiting its development. Also, inhibition of platelet activation by ML354 did not prevent the onset of TRALI. Finally, the stimuli used for TRALI induction also triggered specific platelet activation upon ex vivo stimulation. CONCLUSIONS: This study suggests that blood platelets are not critically required for TRALI induction, although they are to some extent involved in its pathophysiology.


Assuntos
Lesão Pulmonar Aguda Relacionada à Transfusão/prevenção & controle , Animais , Anticorpos/farmacologia , Plaquetas/efeitos dos fármacos , Humanos , Indóis/farmacologia , Camundongos , Ativação Plaquetária/efeitos dos fármacos , Complexo Glicoproteico GPIb-IX de Plaquetas/imunologia
14.
Mol Immunol ; 120: 83-92, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32106023

RESUMO

Pulmonary fibrosis is a progressive chronic inflammatory lung disease whose pathogenesis is complicated. Platelets and neutrophils play important roles in the progression of pulmonary inflammation. We have reported that cangrelor, a non-sepesific GPR17 antagonist, alleviates pulmonary fibrosis partly by inhibiting macrophage inflammation in mice. Cangrelor is also a well-known anti-platelet agent. To test whether cangrelor mitigated pulmonary fibrosis partly through the inhibition of platelets, bleomycin (BLM) was used to induce pulmonary fibrosis in C57BL/6 J mice. We found that cangrelor (10 mg/kg) not only significantly decreased BLM-induced release of inflammatory cytokines (PF4, CD40 L and MPO), but also decreased the increment of platelets, neutrophils and platelet-neutrophil aggregates in the fibrotic lung and in the peripheral blood of BLM-treated mice. In addition, cangrelor decreased the number of CD40 and MPO double positive neutrophils and the expression level of CD40 in BLM-treated mouse lungs. Based on these results we conclude that cangrelor alleviates BLM-induced lung inflammation and pulmonary fibrosis in mice, partly through inhibition of platelet activation, therefore reducing the infiltration of neutrophils due to the adhesion of platelets and neutrophils mediated by CD40 - CD40 L interaction. Cangrelor could be a potential therapeutic medicine for pulmonary fibrosis.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Ativação Plaquetária/efeitos dos fármacos , Fibrose Pulmonar/tratamento farmacológico , Monofosfato de Adenosina/uso terapêutico , Animais , Bleomicina/toxicidade , Antígenos CD40/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Mediadores da Inflamação/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infiltração de Neutrófilos/efeitos dos fármacos , Infiltração de Neutrófilos/imunologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Ativação Plaquetária/imunologia , Inibidores da Agregação de Plaquetas/uso terapêutico , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/imunologia
15.
BMC Cardiovasc Disord ; 20(1): 81, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-32059638

RESUMO

BACKGROUND: Tanshinone IIA (TS IIA), a multi-pharmaceutical compound from traditional Chinese herb, is effective for treatment of atherothrombosis. However, the underlying mechanisms of TS IIA-mediated anti-platelet activation effect are still poorly understood. As shown in our previous study, platelet-derived microvesicles (PMVs) generated in response to oxidant insult could activate CD36/mitogen-activated protein kinase kinase 4/Jun N-terminal kinase 2 (CD36/MKK4/JNK2) signals and lead to platelet activation. The present study aims to investigate the effect of TS IIA on platelet activation and the possible mechanisms. METHODS: The production of PMVs induced by Interleukin 6 (IL-6) was detected by flow cytometry. We performed activating studies of platelets with PMVs derived from IL-6-treated platelets (IL-6-PMVs) in vitro. Sometimes, platelet suspensions were incubated with serial concentrations of TS IIA for 15 min before being stimulated with IL-6-PMVs. Expression of platelet integrin αIIbß3 and CD36 was detected by flow cytometry. Phosphorylation of MKK4 and JNK were detected by immunoblotting. RESULTS: Here we demonstrated firstly that TS IIA could prevent platelet activation induced by PMVs and down-regulates CD36 and MKK4/JNK2 signaling pathway. CD36 may be the target of atherosclerosis (AS)-related thrombosis. CONCLUSIONS: This study showed the possible mechanisms of TS IIA-mediated anti-platelet activation and may provide a new strategy for the treatment of AS-related thrombosis by targeting platelet CD36.


Assuntos
Abietanos/farmacologia , Plaquetas/efeitos dos fármacos , Antígenos CD36/sangue , Micropartículas Derivadas de Células/efeitos dos fármacos , MAP Quinase Quinase 4/sangue , Proteína Quinase 9 Ativada por Mitógeno/sangue , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação de Plaquetas/farmacologia , Plaquetas/enzimologia , Micropartículas Derivadas de Células/enzimologia , Regulação para Baixo , Humanos , Fosforilação , Transdução de Sinais
16.
Biochem Pharmacol ; 174: 113827, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31987853

RESUMO

Adenosine analogues have high affinity and selectivity for adenosine receptors (AR), and exhibit anti-platelet activity. Plasma proteins play an important role in the regulation of platelet function and may influence the action of anti-platelet compounds. Little is known about the interactions of AR agonists with plasma proteins. This study investigates the interplay between AR agonists and plasma proteins and the consequences of those interactions. Surface plasmon resonance was employed together with molecular docking study to determine the binding kinetics of four selected ARagonists (PSB0777, Cl-Ado, MRE0094, UK432097) to several carrier proteins and to clarify the nature of these interactions. The influence of a whole plasma and of some plasma components on the effectiveness of ARagonists in the inhibition of platelet function was assessed by flow cytometry (platelet activation) and ELISA (platelet adhesion). Plasma proteins remarkably diminished the effectiveness of ARagonists in inhibiting platelet activation and adhesion in vitro. ARagonists were found to strongly bind to human serum albumin (HSA) and the protein components of lipoproteins - apolipoproteins; HSA was essential for the binding of water-soluble PSB0777, whereas apolipoproteins were needed for interactions with poorly-water soluble compounds such as UK432097 and MRE0094. In addition, HSA was shown to significantly reduce the effectiveness of PSB0777 in inhibiting ADP-induced platelet activation. In conclusion, HSA and lipoproteins are important carriers for ARagonists, which can affect pharmacodynamics of ARagonists used as platelet inhibitors.


Assuntos
Agonistas do Receptor A2 de Adenosina/farmacologia , Adenosina/farmacologia , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação de Plaquetas/farmacologia , Adenosina/análogos & derivados , Adenosina/química , Agonistas do Receptor A2 de Adenosina/química , Adulto , Feminino , Furanos/química , Furanos/farmacologia , Humanos , Masculino , Simulação de Acoplamento Molecular/métodos , Ativação Plaquetária/fisiologia , Agregação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/fisiologia , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , Receptores Purinérgicos P1/metabolismo , Adulto Jovem
17.
Blood Coagul Fibrinolysis ; 31(2): 132-139, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31913146

RESUMO

: Mycophenolate mofetil (MMF) raises platelet counts in patients with primary immune thrombocytopenia. However, studies indicate that MMF inhibits collagen-induced platelet aggregation, potentially increasing bleeding risk following MMF therapy. The study evaluates the in-vitro effect of MMF on platelet function. Blood samples (n = 6) from healthy donors were incubated with vehicle, MMF or mycophenolic acid (MPA) at clinically relevant concentrations. Platelet aggregation was measured with flow cytometry and 96-well light transmission aggregometry (LTA). Using flow cytometry, we measured the expression of platelet CD49b, CD42b, CD42a, CD61 and CD41. Platelet activation was measured as the expression of P-selectin and the active form of the GPIIb/IIIa receptor following agonist stimulation. Agonists were: ADP, thrombin receptor-activating peptide, collagen, collagen-related peptide and U46619. The Platelet Function Analyzer-200 was used to measure global platelet function. MMF and MPA did not change platelet aggregation regardless of the agonist used. An exception was a significant, but minor decrease in collagen-induced platelet aggregation in samples with MMF (6 ±â€Š3%, P = 0.02) and MPA (8 ±â€Š4%, P = 0.01) compared with vehicle (22 ±â€Š11%). However, this was not observed using the lesser sensitive LTA method. Compared with vehicle, MPA led to a significantly lower relative disposition of the surface collagen-receptor GPVI (7.8 ±â€Š1.8 versus 8.8 ±â€Š2.1 mean fluorescence intensity, P < 0.001). In all other platelet-related tests, neither MMF nor MPA showed any effect. In conclusion, MMF and MPA only had a minor effect on collagen-induced platelet aggregation, with MPA reducing the relative disposition of surface GPVI receptors.


Assuntos
Plaquetas/efeitos dos fármacos , Ácido Micofenólico/farmacologia , Humanos , Ativação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Testes de Função Plaquetária , Glicoproteínas da Membrana de Plaquetas
18.
J Cardiovasc Pharmacol Ther ; 25(3): 191-200, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31960728

RESUMO

Antiplatelet therapy reduces atherothrombotic risk and has therefore become a cornerstone in the treatment of cardiovascular disease. Aspirin, adenosine diphosphate P2Y12 receptor antagonists, glycoprotein IIb/IIIa inhibitors, and the thrombin receptor blocker vorapaxar are effective antiplatelet agents but significantly increase the risk of bleeding. Moreover, atherothrombotic events still impair the prognosis of many patients with cardiovascular disease despite established antiplatelet therapy. Over the last years, advances in the understanding of thrombus formation and hemostasis led to the discovery of various new receptors and signaling pathways of platelet activation. As a consequence, many new antiplatelet agents with high antithrombotic efficacy and supposedly only moderate effects on regular hemostasis have been developed and yielded promising results in preclinical and early clinical studies. Although their long journey from animal studies to randomized clinical trials and finally administration in daily clinical routine has just begun, some of the new agents may in the future become meaningful additions to the pharmacological armamentarium in cardiovascular disease.


Assuntos
Plaquetas/efeitos dos fármacos , Doenças Cardiovasculares/tratamento farmacológico , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação de Plaquetas/uso terapêutico , Animais , Plaquetas/metabolismo , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/diagnóstico , Desenvolvimento de Medicamentos , Descoberta de Drogas , Hemorragia/induzido quimicamente , Humanos , Terapia de Alvo Molecular , Inibidores da Agregação de Plaquetas/efeitos adversos , Transdução de Sinais , Resultado do Tratamento
19.
Medicine (Baltimore) ; 99(4): e18683, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31977858

RESUMO

Vicagrel is a new antiplatelet pro-drug based on clopidogrel sulfur lactone metabolites. The purpose of the study was to evaluate the safety, tolerability, and pharmacodynamics (PD) of vicagrel in healthy Chinese subjects.This study was designed as a single-center, randomized, double-blind, placebo-controlled, single oral ascending dose study. Fifty nine subjects were assigned to 6 vicagrel dose cohorts (5, 10, 20, 40, 60, and 75 mg), and 8 subjects were assigned to 75 mg clopidogrel. Within each vicagrel dose cohort, the 10 subjects (9 in the 75 mg cohort) were randomized 4:1 to receive vicagrel or placebo. Platelet function was assessed using VerifyNow P2Y12. ΔP2Y12 reaction units (ΔPRU) and percent inhibition platelet aggregation (%IPA) were used to evaluate the PD of vicagrel.Although the number of adverse events (AEs) increased with vicagrel dose, none were considered serious, suggesting that vicagrel is safe and well-tolerated. The ΔPRU and %IPA patterns suggest that inhibition of ADP-induced platelet aggregation increased in a dose-dependent manner across the 10 to 40 mg dose range. The inhibitory effect was nearly complete at 4 hours (mean %IPA 87.9%-93.0%, mean ΔPRU 206.6-240.0) for doses of 40 to 75 mg of vicagrel. In contrast, for 5 mg vicagrel and 75 mg clopidogrel, there were no measurable effects on platelet aggregation throughout the study.The results suggest that vicagrel at 40 to 75 mg inhibits ADP-induced platelet aggregation, with a fast onset of action and significantly greater potency than clopidogrel. These findings indicate that vicagrel may be a highly effective and well-tolerated antiplatelet agent.


Assuntos
Fenilacetatos/farmacologia , Inibidores da Agregação de Plaquetas/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Tiofenos/farmacologia , Adulto , Clopidogrel/farmacologia , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Masculino , Fenilacetatos/administração & dosagem , Fenilacetatos/efeitos adversos , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação de Plaquetas/administração & dosagem , Inibidores da Agregação de Plaquetas/efeitos adversos , Testes de Função Plaquetária , Tiofenos/administração & dosagem , Tiofenos/efeitos adversos , Adulto Jovem
20.
Nat Commun ; 11(1): 398, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31964886

RESUMO

A prevailing dogma is that inhibition of vascular thrombosis by antagonizing platelet integrin αIIbß3 cannot be achieved without compromising hemostasis, thus causing serious bleeding and increased morbidity and mortality. It is speculated that these adverse outcomes result from drug-induced activating conformational changes in αIIbß3 but direct proof is lacking. Here, we report the structure-guided design of peptide Hr10 and a modified form of the partial agonist drug tirofiban that act as "pure" antagonists of αIIbß3, i.e., they no longer induce the conformational changes in αIIbß3. Both agents inhibit human platelet aggregation but preserve clot retraction. Hr10 and modified tirofiban are as effective as partial agonist drugs in inhibiting vascular thrombosis in humanized mice, but neither causes serious bleeding, establishing a causal link between partial agonism and impaired hemostasis. Pure orthosteric inhibitors of αIIbß3 may thus provide safer alternatives for human therapy, and valuable tools to probe structure-activity relationships in integrins.


Assuntos
Desenho de Fármacos , Hemorragia/tratamento farmacológico , Peptídeos/farmacologia , Inibidores da Agregação de Plaquetas/farmacologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Trombose/prevenção & controle , Animais , Coagulação Sanguínea/efeitos dos fármacos , Modelos Animais de Doenças , Técnicas de Introdução de Genes , Voluntários Saudáveis , Humanos , Células K562 , Masculino , Camundongos , Camundongos Transgênicos , Peptídeos/química , Peptídeos/uso terapêutico , Ativação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação de Plaquetas/química , Inibidores da Agregação de Plaquetas/uso terapêutico , Testes de Função Plaquetária , Relação Estrutura-Atividade , Tirofibana/química , Tirofibana/uso terapêutico , Fator de von Willebrand/genética
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