scholarly journals Black Sorghum Phenolic Extract Modulates Platelet Activation and Platelet Microparticle Release

Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1760 ◽  
Author(s):  
Borkwei Ed Nignpense ◽  
Kenneth A Chinkwo ◽  
Christopher L Blanchard ◽  
Abishek B Santhakumar
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Conformational Changes ◽  
Thrombus Formation ◽  
Antiplatelet Agents ◽  
Limited Information ◽  
Platelet Activity ◽  
Dietary Polyphenols ◽  
High Antioxidant Activity ◽  
Phenolic Extract

Platelet hyper-activation and platelet microparticles (PMPs) play a key role in the pathogenesis of cardiovascular diseases. Dietary polyphenols are believed to mimic antiplatelet agents by blunting platelet activation receptors via its antioxidant phenomenon. However, there is limited information on the anti-platelet activity of grain-derived polyphenols. The aim of the study is to evaluate the effects of sorghum extract (Shawaya short black 1 variety), an extract previously characterised for its high antioxidant activity and reduction of oxidative stress-related endothelial dysfunction, on platelet aggregation, platelet activation and PMP release. Whole blood samples collected from 18 healthy volunteers were treated with varying non-cytotoxic concentrations of polyphenol-rich black sorghum extract (BSE). Platelet aggregation study utilised 5 µg/mL collagen to target the GPVI pathway of thrombus formation whereas adenine phosphate (ADP) was used to stimulate the P2Y1/P2Y12 pathway of platelet activation assessed by flow cytometry. Procaspase-activating compound 1 (PAC-1) and P-selectin/CD62P were used to evaluate platelet activation- related conformational changes and degranulation respectively. PMPs were isolated from unstimulated platelets and quantified by size distribution and binding to CD42b. BSE treatment significantly reduced both collagen-induced platelet aggregation and circulatory PMP release at 40 µg/mL (p < 0.001) when compared to control. However, there was no significant impact of BSE on ADP-induced activation-dependent conformational change and degranulation of platelets. Results of this study suggest that phenolic rich BSE may confer cardio-protection by modulating specific signalling pathways involved in platelet activation and PMP release.

scholarly journals An Antithrombotic Strategy by Targeting Phospholipase D in Human Platelets

2018 ◽  
Vol 7 (11) ◽  
pp. 440 ◽  
Author(s):  
Wan Lu ◽  
Chi Chung ◽  
Ray Chen ◽  
Li Huang ◽  
Li Lien ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Phospholipase D ◽  
Thrombus Formation ◽  
Human Platelets ◽  
Platelet Activity ◽  
Clot Retraction ◽  
First Time

Phospholipase D (PLD) is involved in many biological processes. PLD1 plays a crucial role in regulating the platelet activity of mice; however, the role of PLD in the platelet activation of humans remains unclear. Therefore, we investigated whether PLD is involved in the platelet activation of humans. Our data revealed that inhibition of PLD1 or PLD2 using pharmacological inhibitors effectively inhibits platelet aggregation in humans. However, previous studies have showed that PLD1 or PLD2 deletion did not affect mouse platelet aggregation in vitro, whereas only PLD1 deletion inhibited thrombus formation in vivo. Intriguingly, our data also showed that the pharmacological inhibition of PLD1 or PLD2 does not affect mouse platelet aggregation in vitro, whereas the inhibition of only PLD1 delayed thrombus formation in vivo. These findings indicate that PLD may play differential roles in humans and mice. In humans, PLD inhibition attenuates platelet activation, adhesion, spreading, and clot retraction. For the first time, we demonstrated that PLD1 and PLD2 are essential for platelet activation in humans, and PLD plays different roles in platelet function in humans and mice. Our findings also indicate that targeting PLD may provide a safe and alternative therapeutic approach for preventing thromboembolic disorders.

scholarly journals Preparations from selected cucurbit vegetables as antiplatelet agents

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Agata Rolnik ◽  
Bartosz Skalski ◽  
Anna Stochmal ◽  
Beata Olas
Keyword(s):  
Platelet Activation ◽  
Cucurbita Pepo ◽  
Fruits And Vegetables ◽  
Thrombus Formation ◽  
Blood Platelets ◽  
Antiplatelet Agents ◽  
Blood Platelet ◽  
Arachidonic Acid Metabolism ◽  
Platelet Activity ◽  
Activated Platelets

AbstractIncreased blood platelet activation plays an important role in cardiovascular diseases (CVDs). Recent experiments indicate that certain fruits and vegetables, including onion, garlic, and beetroot, have anti-platelet potential and therefore may reduce the likelihood of CVDs. While vegetables from the Cucuritaceae family are known to exerting beneficial antioxidant and anti-inflammatory effects, their effects on blood platelet activation are poorly understood. Therefore, the aim of the present study was to determine the effect on platelet adhesion of preparations from selected cucurbits: pumpkin (Cucurbita pepo; fruit without seeds), zucchini (Cucurbita pepo convar. giromontina; fruit with seeds), cucumber (Cucumis sativus; fruit with seeds), white pattypan squash (Cucurbita pepo var. patisoniana; fruit without seeds) and yellow pattypan squash (Cucurbita pepo var. patisoniana, fruit without seeds). It also evaluates the activity of these preparations on enzymatic lipid peroxidation in thrombin-activated washed blood platelets by TBARS assay. The study also determines the anti-platelet properties of these five cucurbit preparations in whole blood by flow cytometry and with the total thrombus-formation analysis system (T-TAS) and evaluates the cytotoxicity of the tested preparations against platelets based on LDH activity. The results indicate that the yellow Cucurbita pepo var. patisoniana preparation demonstrated stronger anti-platelet properties than the other tested preparations, reducing the adhesion of thrombin-activated platelets to collagen/fibrinogen, and inhibiting arachidonic acid metabolism and GPIIb/IIIa expression on 10 µM ADP-activated platelets. None of the preparations was found to cause platelet lysis. Our findings provide new information on the anti-platelet activity of the tested cucurbit preparations and their potential for treating CVDs associated with platelet hyperactivity.

FUNDC2 regulates platelet activation through AKT/GSK-3β/cGMP axis

2018 ◽  
Vol 115 (11) ◽  
pp. 1672-1679 ◽  
Author(s):  
Qi Ma ◽  
Weilin Zhang ◽  
Chongzhuo Zhu ◽  
Junling Liu ◽  
Quan Chen
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Platelet Rich Plasma ◽  
Thrombus Formation ◽  
Mitochondrial Protein ◽  
Dependent Manner ◽  
Clot Retraction ◽  
Akt Phosphorylation ◽  
Gsk 3Β

Abstract Aims AKT kinase is vital for regulating signal transduction in platelet aggregation. We previously found that mitochondrial protein FUNDC2 mediates phosphoinositide 3-kinase (PI3K)/phosphatidylinositol-3,4,5-trisphosphate (PIP3)-dependent AKT phosphorylation and regulates platelet apoptosis. The aim of this study was to evaluate the role of FUNDC2 in platelet activation and aggregation. Methods and results We demonstrated that FUNDC2 deficiency diminished platelet aggregation in response to a variety of agonists, including adenosine 5′-diphosphate (ADP), collagen, ristocetin/VWF, and thrombin. Consistently, in vivo assays of tail bleeding and thrombus formation showed that FUNDC2-knockout mice displayed deficiency in haemostasis and thrombosis. Mechanistically, FUNDC2 deficiency impairs the phosphorylation of AKT and downstream GSK-3β in a PI3K-dependent manner. Moreover, cGMP also plays an important role in FUNDC2/AKT-mediated platelet activation. This FUNDC2/AKT/GSK-3β/cGMP axis also regulates clot retraction of platelet-rich plasma. Conclusion FUNDC2 positively regulates platelet functions via AKT/GSK-3β/cGMP signalling pathways, which provides new insight for platelet-related diseases.

scholarly journals Doxorubicin contributes to thrombus formation and vascular injury by interfering with platelet function

2020 ◽  
Vol 319 (1) ◽  
pp. H133-H143 ◽  
Author(s):  
Haichen Lv ◽  
Ruopeng Tan ◽  
Jiawei Liao ◽  
Zhujing Hao ◽  
Xiaolei Yang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Platelet Aggregation ◽  
Vascular Injury ◽  
Platelet Function ◽  
Thrombus Formation ◽  
Platelet Activity ◽  
Vascular Toxicity ◽  
Platelet Functions

Doxorubicin therapy in mice (antitumor dosage) markedly enhanced platelet functions measured as agonist-induced platelet aggregation, degranulation, and adhesion to endothelial cells, actions leading to thrombus formation and thrombosis-independent vascular injury. Clopidogrel treatment ameliorated thrombus formation and vascular toxicity induced by doxorubicin via inhibiting platelet activity.

scholarly journals Role of GRK6 in the Regulation of Platelet Activation through Selective G Protein-Coupled Receptor (GPCR) Desensitization

2020 ◽  
Vol 21 (11) ◽  
pp. 3932 ◽  
Author(s):  
Preeti Kumari Chaudhary ◽  
Sanggu Kim ◽  
Youngheun Jee ◽  
Seung-Hun Lee ◽  
Kyung-Mee Park ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
G Protein ◽  
Platelet Activation ◽  
Functional Role ◽  
Thrombus Formation ◽  
Receptor Activation ◽  
G Protein Coupled ◽  
Gpcr Desensitization ◽  
Stimulation Of

Platelet G protein-coupled receptors (GPCRs) regulate platelet function by mediating the response to various agonists, including adenosine diphosphate (ADP), thromboxane A2, and thrombin. Although GPCR kinases (GRKs) are considered to have the crucial roles in most GPCR functions, little is known regarding the regulation of GPCR signaling and mechanisms of GPCR desensitization by GRKs in platelets. In this study, we investigated the functional role of GRK6 and the molecular basis for regulation of specific GPCR desensitization by GRK6 in platelets. We used GRK6 knockout mice to evaluate the functional role of GRK6 in platelet activation. Platelet aggregation, dense- and α-granule secretion, and fibrinogen receptor activation induced by 2-MeSADP, U46619, thrombin, and AYPGKF were significantly potentiated in GRK6−/− platelets compared to the wild-type (WT) platelets. However, collagen-related peptide (CRP)-induced platelet aggregation and secretion were not affected in GRK6−/− platelets. Interestingly, platelet aggregation induced by co-stimulation of serotonin and epinephrine which activate Gq-coupled 5HT2A and Gz-coupled α2A adrenergic receptors, respectively, was not affected in GRK6−/− platelets, suggesting that GRK6 was involved in specific GPCR regulation. In addition, platelet aggregation in response to the second challenge of ADP and AYPGKF was restored in GRK6−/− platelets whereas re-stimulation of the agonist failed to induce aggregation in WT platelets, indicating that GRK6 contributed to P2Y1, P2Y12, and PAR4 receptor desensitization. Furthermore, 2-MeSADP-induced Akt phosphorylation and AYPGKF-induced Akt, extracellular signal-related kinase (ERK), and protein kinase Cδ (PKCδ) phosphorylation were significantly potentiated in GRK6−/− platelets. Finally, GRK6−/− mice exhibited an enhanced and stable thrombus formation after FeCl3 injury to the carotid artery and shorter tail bleeding times, indicating that GRK6−/− mice were more susceptible to thrombosis and hemostasis. We conclude that GRK6 plays an important role in regulating platelet functional responses and thrombus formation through selective GPCR desensitization.

scholarly journals Noncanonical Effects of Oral Thrombin and Factor Xa Inhibitors in Platelet Activation and Arterial Thrombosis

2020 ◽  
Author(s):  
Amin Polzin ◽  
Lisa Dannenberg ◽  
Manuela Thienel ◽  
Martin Orban ◽  
Georg Wolff ◽  
...  
Keyword(s):  
Platelet Activation ◽  
Arterial Thrombosis ◽  
Thrombus Formation ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Factor Xa ◽  
Coagulation Cascade ◽  
Platelet Activity ◽  
Vein Thrombosis

AbstractNonvitamin K oral anticoagulants (NOACs) or direct oral anticoagulants comprise inhibitors of factor Xa (rivaroxaban, apixaban, edoxaban) or factor IIa (dabigatran). Both classes efficiently interfere with the final or penultimate step of the coagulation cascade and showed superior net clinical benefit compared with vitamin K antagonists for prevention of thromboembolic events in patients with AF and for prevention and therapy of deep vein thrombosis and pulmonary embolism. None the less, accumulating data suggested, that there may be differences regarding the frequency of atherothrombotic cardiovascular events between NOACs. Thus, the optimal individualized NOAC for each patient remains a matter of debate. Against this background, some basic and translational analyses emphasized NOAC effects that impact on platelet activity and arterial thrombus formation beyond inhibition of plasmatic coagulation. In this review, we will provide an overview of the available clinical and translational evidence for so-called noncanonical NOAC effects on platelet activation and arterial thrombosis.

scholarly journals Antiplatelet Activity ofMorus albaLeaves Extract, Mediated via Inhibiting Granule Secretion and Blocking the Phosphorylation of Extracellular-Signal-Regulated Kinase and Akt

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Dong-Seon Kim ◽  
Hyun Dong Ji ◽  
Man Hee Rhee ◽  
Yoon-Young Sung ◽  
Won-Kyung Yang ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Thrombus Formation ◽  
Underlying Mechanism ◽  
Serotonin Release ◽  
Platelet Activity ◽  
Antithrombotic Agent ◽  
Serotonin Secretion ◽  
Venous Shunt ◽  
Granule Secretion

Ethnopharmacological Relevance.Morus albaL. leaves (MAE) have been used in fork medicine for the treatment of beriberi, edema, diabetes, hypertension, and atherosclerosis. However, underlying mechanism of MAE on cardiovascular protection remains to be elucidated. Therefore, we investigated whether MAE affect platelet aggregation and thrombosis.Materials and Methods. The anti-platelet activity of MAE was studied using rat platelets. The extent of anti-platelet activity of MAE was assayed in collagen-induced platelet aggregation. ATP and serotonin release was carried out. The activation of integrinαIIbβ3and phosphorylation of signaling molecules, including MAPK and Akt, were investigated with cytofluorometer and immunoblotting, respectively. The thrombus formationin vivowas also evaluated in arteriovenous shunt model of rats.Results. HPLC chromatographic analysis revealed that MAE contained rutin and isoquercetin. MAE dose-dependently inhibited collagen-induced platelet aggregation. MAE also attenuated serotonin secretion and thromboxane A2formation. In addition, the extractin vivoactivity showed that MAE at 100, 200, and 400 mg/kg significantly and dose-dependently attenuated thrombus formation in rat arterio-venous shunt model by 52.3% (P<0.001), 28.3% (P<0.01), and 19.1% (P<0.05), respectively.Conclusions. MAE inhibit platelet activation, TXB2 formation, serotonin secretion, aggregation, and thrombus formation. The plant extract could be considered as a candidate to anti-platelet and antithrombotic agent.

CalDAG-GEFI Is a Key Signal Integrator in Platelet Activation and Thrombus Formation.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 326-326
Author(s):  
Wolfgang Bergmeier ◽  
Jill R. Crittenden ◽  
Crystal L. Piffath ◽  
Denisa D. Wagner ◽  
David E. Housman ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Knockout Mice ◽  
Thrombus Formation ◽  
Es Cells ◽  
Embryonic Stem ◽  
Premature Stop Codon ◽  
Small Gtpase ◽  
Integrin Αiibβ3

Abstract Inside-out activation of platelet integrin αIIbβ3 is a key step in agonist-induced platelet aggregation. Recent studies suggested the involvement of the small GTPase Rap1b in this process as it is highly expressed in platelets and becomes activated during platelet activation. In cell lines, overexpression of the Rap activator CalDAG-GEFI increased αIIbβ3-dependent adhesion, while overexpression of RapGAP, which inactivates Rap1, reduced αIIbβ3 activity. Here we provide evidence that CalDAG-GEFI is an essential component of this pathway in vivo. To generate CalDAG-GEFI knockout mice, we engineered mouse embryonic stem (ES) cells with a deletion that results in a frameshift mutation and a premature stop codon at the position encoding the 37th amino acid of CalDAG-GEFI. These ES cells were then used to derive chimeric mice that yielded germline transmission of the CalDAG-GEFI mutation. Deficiency of CalDAG-GEFI in mutant mice was confirmed by immunohistochemistry and western blot analysis. CalDAG-GEFI−/− platelets showed impaired Rap1b activation and aggregation in response to various agonists, with aggregation being completely blocked when platelets were activated with ADP, thromboxaneA2 analog, or calcium ionophore. Under physiological flow conditions in vitro and in vivo, CalDAG-GEFI-deficient platelets showed normal tethering to basement membrane components but failed to form thrombi. Mice deficient in CalDAG-GEFI were further characterized by a greatly increased bleeding time as well as by a strong protection against collagen-induced pulmonary thrombosis. In summary, we identified CalDAG-GEFI as a key signal integrator in the cascade leading through Rap1 and integrin αIIbβ3 to platelet aggregation and thrombus formation. The fact that CalDAG-GEFI knockout mice are resistant to collagen-induced thrombosis, and do not undergo spontaneous hemorrhaging, suggests that CalDAG-GEFI may be a promising new target for antithrombotic therapy.

LPS Stimulates Platelet Secretion and Promotes Platelet Aggregation Via TLR4/MyD88 and the cGMP-Dependent Protein Kinase Pathway.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3658-3658
Author(s):  
Guoying Zhang ◽  
Emily Welch ◽  
Asrar B. Malik ◽  
Xiaoping Du ◽  
Zhenyu Li
Keyword(s):  
Platelet Aggregation ◽  
Protein Kinase ◽  
Platelet Activation ◽  
Thrombus Formation ◽  
Critical Role ◽  
Atp Release ◽  
Dependent Protein Kinase ◽  
Cgmp Dependent Protein Kinase ◽  
Dependent Protein ◽  
Platelet Secretion

Abstract Bacterial lipopolysaccharide (LPS) induces rapid thrombocytopenia, hypotension and sepsis. Although growing evidence suggests that platelet activation plays a critical role in LPS-induced thrombocytopenia and tissue damage, the mechanism of LPS-mediated platelet activation is unclear. Here we show that LPS stimulated platelet secretion of dense and alpha granules as indicated by ATP release and P-selectin expression, and thus enhanced platelet activation induced by low concentrations of platelet agonists. Platelets express components of the LPS receptor-signaling complex, including Toll-like receptor (TLR4), CD14, MD2, and MyD88. The effect of LPS on platelet activation was abolished by an anti-TLR4 blocking antibody or TLR4 knockout. Furthermore, LPS-induced potentiation of platelet aggregation and FeCl3-induced thrombus formation were abolished in MyD88 knockout mice. Importantly, TLR4 mediates LPS-induced cGMP elevation and the stimulatory effect of LPS on platelet aggregation was also abolished by inhibitors of nitric oxide synthase (NOS) and the cGMP-dependent protein kinase (PKG). Thus, LPS promotes platelet secretion and aggregation through a TLR4/MyD88 and cGMP/PKG-dependent pathway.

YM150, An Oral Direct Factor Xa Inhibitor: Combination with Aspirin or Clopidogrel In Arteriovenous Shunt Thrombosis In Rats

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3318-3318
Author(s):  
Yoshiyuki Iwatsuki ◽  
Chinatsu Sakata ◽  
Yumiko Moritani
Keyword(s):  
Platelet Aggregation ◽  
Arterial Thrombosis ◽  
Bleeding Time ◽  
Thrombus Formation ◽  
Control Level ◽  
Factor Xa ◽  
Antiplatelet Agents ◽  
Factor Xa Inhibitor ◽  
Direct Factor ◽  
Silk Thread

Abstract Abstract 3318 Background: YM150, an oral direct factor Xa inhibitor, is currently in clinical development for the prevention of venous thromboembolism in patients undergoing orthopedic surgery, prevention of stroke in patients with atrial fibrillation, and prevention of ischemic events after recent acute coronary syndrome (ACS). The antiplatelet agents aspirin or clopidogrel will likely be co-prescribed with YM150 in ACS. Here, we report the effects of YM150 in combination with aspirin or clopidogrel on thrombus formation, bleeding, platelet aggregation, and coagulation in rats. Methods: The antithrombotic effect was estimated in a rat arteriovenous shunt model. The shunt was formed by attaching a polyethylene tube containing a silk thread to the carotid artery and the contralateral carotid vein. Blood was allowed to circulate in this shunt for 15 min, and then the silk thread was withdrawn from the tube to assess the thrombus weight. YM150, aspirin, or clopidogrel was orally administered 0.5, 1, or 2 h before shunt formation, respectively. At the same time as shunt formation, an incision was made at the sole of the left foot using a template bleeding device (Surgicutt®) to measure bleeding time. To avoid interference with the thrombosis model, blood samples to assess platelet aggregation and prothrombin time were obtained from separate animals at the same time point as shunt formation in the thrombus study. Platelet aggregation was induced using 10 μg/mL of collagen and 5 μM of adenosine 5`-diphosphate (ADP) to assess the effects of aspirin and clopidogrel, respectively. Results: YM150 alone inhibited thrombus formation, with significance at 10 mg/kg and more (P < 0.05). Respective thrombus weights in the control, 3, 10, and 30 mg/kg groups of YM150 were 4.8, 3.6, 2.4, and 2.0 mg. Aspirin alone inhibited thrombus formation, with significance at 100 mg/kg and more (P < 0.01). Respective thrombus weights in the control, 30, 100, and 300 mg/kg group of aspirin were 6.2, 4.2, 2.8, and 1.5 mg. Clopidogrel alone inhibited thrombus formation, with significance at 1 mg/kg and more (P < 0.01). Respective thrombus weights in the control, 0.3, 1, and 3 mg/kg group of clopidogrel were 4.8, 3.6, 2.9, and 1.3 mg. When administered concomitantly with 100 mg/kg of aspirin, YM150 (3, 10, 30 mg/kg) further inhibited thrombogenesis, with significance at 30 mg/kg of YM150 (P < 0.05) and thrombus weights of 2.4, 1.5, and 1.3 mg, respectively. When administered concomitantly with 1 mg/kg of clopidogrel, YM150 (3, 10, 30 mg/kg) further inhibited thrombogenesis, with significance at 30 mg/kg of YM150 (P < 0.05) and thrombus weights of 3.0, 2.0, and 1.5 mg, respectively. Collagen-induced platelet aggregation was reduced to 16.7% of the control level by 100 mg/kg of aspirin, and ADP-induced platelet aggregation was reduced to 74.4% of the control level by 1 mg/kg of clopidogrel. These effects were not changed in the presence of YM150. Prothrombin time and bleeding time were not prolonged by any of the agents alone, and further, these parameters were not affected by combined use of YM150 with either aspirin or clopidogrel. Conclusions: The thrombosis study suggests that both the platelet aggregation and coagulation cascade participate in thrombus formation in this model since both antiplatelet agents and the anticoagulant YM150 were effective. Thus, the thrombosis induced in this model can be considered similar to arterial thrombosis in humans where both platelets and fibrin are involved. Taken together, YM150 is a promising antithrombotic agent that augments the effects of antiplatelet agents against arterial thrombosis without increasing bleeding risk. Disclosures: Iwatsuki: Astellas Phama Inc.: Employment. Sakata:Astellas Phama Inc.: Employment. Moritani:Astellas Phama Inc.: Employment.

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