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Nam GS, Kim S, Kwon YS, Kim MK, Nam KS. A new function for MAP4K4 inhibitors during platelet aggregation and platelet-mediated clot retraction. Biochem Pharmacol 2021; 188:114519. [PMID: 33737052 DOI: 10.1016/j.bcp.2021.114519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 02/22/2021] [Accepted: 03/10/2021] [Indexed: 11/19/2022]
Abstract
Mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) is implicated in type 2 diabetes mellitus, insulin tolerance, inflammation, cancer, and atherosclerosis. We found that GNE 495 and PF 06260933 (both potent and selective MAP4K4 inhibitors) regulated human platelet activation. Immunoblotting revealed human platelets express MAP4K4, and that GNE 495 and PF 06260933 inhibited collagen-, ADP-, and thrombin-induced platelet aggregation and eventually suppressed granule release, TXA2 generation, integrin αIIbβ3 activation, and clot retraction. In addition, both inhibitors elevated intracellular levels of cAMP, and coincubation with GNE 495 and aspirin or dipyridamole (a phosphodiesterase inhibitor) synergistically inhibited collagen-induced platelet aggregation and TXA2 generation. Moreover, both inhibitors phosphorylated VASP (ser157), IP3 receptor, and PKA and attenuated MAPK and PI3K/Akt/GSK3β signaling pathways. This study is the first to demonstrate that MAP4K4 inhibitors reduce thrombus formation by inhibiting platelet activation. These findings also suggest MAP4K4 be considered an emerging target protein for the treatment of thrombosis.
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Affiliation(s)
- Gi Suk Nam
- Department of Pharmacology and Intractable Disease Research Center, School of Medicine, Dongguk University, Gyeongju, Gyeongsangbuk-do, 38066, Republic of Korea
| | - Soyoung Kim
- Department of Pharmacology and Intractable Disease Research Center, School of Medicine, Dongguk University, Gyeongju, Gyeongsangbuk-do, 38066, Republic of Korea
| | - Yun-Suk Kwon
- Department of Pharmacology and Intractable Disease Research Center, School of Medicine, Dongguk University, Gyeongju, Gyeongsangbuk-do, 38066, Republic of Korea
| | - Min-Kyung Kim
- Department of Pathology, School of Medicine, Dongguk University, Gyeongju, Gyeongsangbuk-do, 38066, Republic of Korea.
| | - Kyung-Soo Nam
- Department of Pharmacology and Intractable Disease Research Center, School of Medicine, Dongguk University, Gyeongju, Gyeongsangbuk-do, 38066, Republic of Korea.
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Long C, Liu M, Tian H, Li Y, Wu F, Mwangi J, Lu Q, Mohamed Abd El-Aziz T, Lai R, Shen C. Potential Role of Platelet-Activating C-Type Lectin-Like Proteins in Viper Envenomation Induced Thrombotic Microangiopathy Symptom. Toxins (Basel) 2020; 12:E749. [PMID: 33260875 PMCID: PMC7760373 DOI: 10.3390/toxins12120749] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 11/11/2020] [Accepted: 11/20/2020] [Indexed: 12/12/2022] Open
Abstract
Envenomation by viperid snakes may lead to severe bleeding, consumption coagulopathy, and thrombotic microangiopathy symptoms. The exact etiology or toxins responsible for thrombotic microangiopathy symptoms after snake envenomation remain obscure. Snake C-type lectin-like proteins (snaclecs) are one of the main non-enzymatic protein constituents in viper venoms, of which a majority are considered as modulators of thrombosis and hemostasis. In this study, we demonstrated that two snaclecs (mucetin and stejnulxin), isolated and identified from Protobothrops mucrosquamatus and Trimeresurus stejnegeri venoms, directly induced platelet degranulation and clot-retraction in vitro, and microvascular thrombosis has been confirmed in various organs in vivo. These snaclecs reduced cerebral blood flow and impaired motor balance and spatial memories in mice, which partially represent the thrombotic microangiopathy symptoms in some snakebite patients. The functional blocking of these snaclecs with antibodies alleviated the viper venom induced platelet activation and thrombotic microangiopathy-like symptoms. Understanding the pathophysiology of thrombotic microangiopathy associated with snake envenoming may lead to emerging therapeutic strategies.
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Affiliation(s)
- Chengbo Long
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human, Disease Mechanisms of Chinese Academy of Sciences, Kunming Institute of Zoology, KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; (C.L.); (H.T.); (F.W.); (J.M.); (Q.L.); (R.L.)
- School of Life Sciences, University of Chinese Academy of Sciences, Beijing 100009, China
| | - Ming Liu
- Department of Molecular and Cell Biology, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China;
| | - Huiwen Tian
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human, Disease Mechanisms of Chinese Academy of Sciences, Kunming Institute of Zoology, KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; (C.L.); (H.T.); (F.W.); (J.M.); (Q.L.); (R.L.)
| | - Ya Li
- Key Laboratory of Laboratory Medicine of Yunnan Province/Department of Clinical Laboratory, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, China;
| | - Feilong Wu
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human, Disease Mechanisms of Chinese Academy of Sciences, Kunming Institute of Zoology, KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; (C.L.); (H.T.); (F.W.); (J.M.); (Q.L.); (R.L.)
- School of Life Sciences, University of Chinese Academy of Sciences, Beijing 100009, China
| | - James Mwangi
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human, Disease Mechanisms of Chinese Academy of Sciences, Kunming Institute of Zoology, KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; (C.L.); (H.T.); (F.W.); (J.M.); (Q.L.); (R.L.)
- School of Life Sciences, University of Chinese Academy of Sciences, Beijing 100009, China
| | - Qiumin Lu
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human, Disease Mechanisms of Chinese Academy of Sciences, Kunming Institute of Zoology, KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; (C.L.); (H.T.); (F.W.); (J.M.); (Q.L.); (R.L.)
- Key Laboratory of Cardiovascular Disease of Yunnan Province, Kunming 650051, China
| | - Tarek Mohamed Abd El-Aziz
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA;
- Zoology Department, Faculty of Science, Minia University, El-Minia 61519, Egypt
| | - Ren Lai
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human, Disease Mechanisms of Chinese Academy of Sciences, Kunming Institute of Zoology, KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; (C.L.); (H.T.); (F.W.); (J.M.); (Q.L.); (R.L.)
- Sino-African Joint Research Center, CAS, Kunming Institute of Zoology, Kunming 650223, China
| | - Chuanbin Shen
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human, Disease Mechanisms of Chinese Academy of Sciences, Kunming Institute of Zoology, KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; (C.L.); (H.T.); (F.W.); (J.M.); (Q.L.); (R.L.)
- Department of Laboratory Medicine, LKSKI-Keenan Research Centre for Biomedical Science, St. Michael’s Hospital, University of Toronto, Toronto, ON M5B 1W8, Canada
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3
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Beke Debreceni I, Mezei G, Batár P, Illés Á, Kappelmayer J. Dasatinib Inhibits Procoagulant and Clot Retracting Activities of Human Platelets. Int J Mol Sci 2019; 20:ijms20215430. [PMID: 31683623 PMCID: PMC6862041 DOI: 10.3390/ijms20215430] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/28/2019] [Accepted: 10/30/2019] [Indexed: 12/29/2022] Open
Abstract
Tyrosine kinase inhibitors (TKI) such as the BCR-ABL inhibitor dasatinib and nilotinib are highly effective therapies for chronic myeloid leukemia (CML). However, several lines of evidence suggest that dasatinib can induce bleeding which may be due to impaired collagen-induced platelet adhesion, aggregation, and secretion. Sarcoma family kinases (SFK) play central role in the GPVI-induced signaling pathway. We aimed to investigate whether and how dasatinib can modulate SFK-mediated platelet procoagulant activity in a purified system and in dasatinib/nilotinib treated CML patients. In platelet rich plasmas of healthy volunteers, dasatinib dose-dependently reduced convulxin-induced phosphatidylserine exposure and attenuated thrombin formation. Similarly to these changes, integrin activation and clot retraction were also significantly inhibited by 100 nM dasatinib. Platelets isolated from dasatinib treated patients showed a significantly lower phosphatidylserine expression upon convulxin activation compared to premedication levels. In these samples, thrombin generation was significantly slower, and the quantity of formed thrombin was less compared to the trough sample. Western blot analyses showed decreased phosphorylation levels of the C-terminal tail and the activation loop of SFKs upon dasatinib administration. Taken together, these results suggest that dasatinib inhibits the formation of procoagulant platelets via the GPVI receptor by inhibiting phosphorylation of SFKs.
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Affiliation(s)
- Ildikó Beke Debreceni
- Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, Kálmán Laki Doctoral School, 4032 Debrecen, Hungary.
| | - Gabriella Mezei
- Division of Hematology, Department of Internal Medicine, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary.
| | - Péter Batár
- Division of Hematology, Department of Internal Medicine, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary.
| | - Árpád Illés
- Division of Hematology, Department of Internal Medicine, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary.
| | - János Kappelmayer
- Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, Kálmán Laki Doctoral School, 4032 Debrecen, Hungary.
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Misztal T, Golaszewska A, Tomasiak-Lozowska MM, Iwanicka M, Marcinczyk N, Leszczynska A, Chabielska E, Rusak T. The myeloperoxidase product, hypochlorous acid, reduces thrombus formation under flow and attenuates clot retraction and fibrinolysis in human blood. Free Radic Biol Med 2019; 141:426-437. [PMID: 31279970 DOI: 10.1016/j.freeradbiomed.2019.07.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 05/24/2019] [Accepted: 07/03/2019] [Indexed: 10/26/2022]
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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Affiliation(s)
- Tomasz Misztal
- Department of Physical Chemistry, Medical University of Bialystok, Kilinskiego 1, 15-089, Bialystok, Poland.
| | - Agata Golaszewska
- Department of Physical Chemistry, Medical University of Bialystok, Kilinskiego 1, 15-089, Bialystok, Poland.
| | | | - Marta Iwanicka
- Department of Physical Chemistry, Medical University of Bialystok, Kilinskiego 1, 15-089, Bialystok, Poland.
| | - Natalia Marcinczyk
- Department of Biopharmacy, Medical University of Bialystok, Kilinskiego 1, 15-089, Bialystok, Poland.
| | - Agnieszka Leszczynska
- Department of Biopharmacy, Medical University of Bialystok, Kilinskiego 1, 15-089, Bialystok, Poland.
| | - Ewa Chabielska
- Department of Biopharmacy, Medical University of Bialystok, Kilinskiego 1, 15-089, Bialystok, Poland.
| | - Tomasz Rusak
- Department of Physical Chemistry, Medical University of Bialystok, Kilinskiego 1, 15-089, Bialystok, Poland.
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Frelinger AL, Jakubowski JA, Li Y, Barnard MR, Linden MD, Tarnow I, Fox ML, Sugidachi A, Winters KJ, Furman MI, Michelson AD. The active metabolite of prasugrel inhibits adenosine diphosphate- and collagen-stimulated platelet procoagulant activities. J Thromb Haemost 2008; 6:359-65. [PMID: 18021304 DOI: 10.1111/j.1538-7836.2008.02838.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
BACKGROUND Prasugrel is a novel antiplatelet prodrug of the same thienopyridine class as clopidogrel and ticlopidine. Metabolism of prasugrel generates the active metabolite R-138727, an antagonist of the platelet P2Y(12) adenosine diphosphate (ADP) receptor, leading to inhibition of ADP-mediated platelet activation and aggregation. ADP also enhances the platelet response to collagen, and these two agonists contribute to the generation of platelet procoagulant activity. We therefore examined whether R-138727 inhibits ADP- and collagen-triggered platelet procoagulant activities. METHODS AND RESULTS As shown by whole blood flow cytometry, R-138727 inhibited surface phosphatidylserine expression on ADP plus collagen-stimulated platelets and tissue factor (TF) expression on ADP-, collagen-, and ADP plus collagen-stimulated monocyte-platelet aggregates. R-138727 reduced monocyte-platelet aggregate formation, thereby further inhibiting TF expression. ADP, collagen, and ADP plus collagen accelerated the kinetics of thrombin generation in recalcified whole blood and R-138727 significantly inhibited this acceleration. Clot strength in a modified thromboelastograph system was also inhibited by R-138727 (IC50 0.7 +/- 0.1 microM). CONCLUSIONS In addition to its previously known inhibitory effects on platelet activation and aggregation, the active metabolite of prasugrel, R-138727, inhibits platelet procoagulant activity in whole blood (as determined by phosphatidylserine expression on platelets and TF expression on monocyte-platelet aggregates), resulting in the functional consequences of delayed thrombin generation and impaired clot development.
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Affiliation(s)
- A L Frelinger
- Center for Platelet Function Studies, and Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA 01655, USA.
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Brophy DF, Martin EJ, Nolte ME, Kuhn JG, Carr ME. Effect of recombinant factor VIIa variant (NN1731) on platelet function, clot structure and force onset time in whole blood from healthy volunteers and haemophilia patients. Haemophilia 2007; 13:533-41. [PMID: 17880440 DOI: 10.1111/j.1365-2516.2007.01524.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
NN1731 is a novel variant of recombinant factor VIIa (rFVIIa) that binds to activated platelets, but has greater enzymatic activity than rFVIIa in generating FXa and thrombin. The effect of NN1731 on clot structure and platelet function was characterized ex vivo in whole blood from healthy volunteers and haemophilic patients. Blood samples from six healthy volunteers, nine haemophilia A patients with and without inhibitors and one acquired haemophilia A patient, were spiked with increasing concentrations (0.32, 0.64 and 1.28 microg mL(-1)) of rFVIIa and NN1731. Platelet contractile force (PCF) or platelet function, clot elastic modulus (CEM) or clot structure, and force onset time (FOT) or the thrombin generation time (TGT) were determined using the Hemodyne Hemostasis Analysis System (HAS). Baseline PCF, CEM and FOT values in patients were abnormal compared to healthy volunteers' baseline values. Overall, haemophilia blood samples with or without inhibitors spiked with NN1731 had significantly greater PCF, CEM and shorter FOT values relative to samples spiked with corresponding doses of rFVIIa. The variability in response to treatment between patients was greater with rFVIIa compared to NN1731. At 1.28 microg mL(-1) (90 microg kg(-1)), NN1731 normalized PCF, CEM and FOT in nine of 10 patients, while rFVIIa normalized these parameters in four of 10 patients. Increasing in vitro concentrations of NN1731 normalized platelet function, clot structure and thrombin generation consistently in haemophilia blood with or without inhibitors. NN1731 may be a promising haemostatic agent for patients with bleeding disorders. These results should be confirmed in an in vivo study.
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Affiliation(s)
- D F Brophy
- Coagulation Special Studies Laboratory, Department of Pharmacy of Virginia Commonwealth University, Richmond, VA 23298, USA.
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Abstract
Fondaparinux is a new anticoagulant that interacts with antithrombin III and activated coagulation factor X resulting in an inhibition of the coagulation system. It has been successful in doses of 2.5 mg for thromboprophylaxis as well as in higher therapeutic doses of 5-7.5 mg. No optimal method for monitoring the effects of fondaparinux has been proposed. The aim of the present study was to investigate whether a viscoelastic coagulation analyzer, the Sonoclot (Sienco, Denver, Colorado, USA), could be used for in-vitro monitoring of fondaparinux. Different concentrations of fondaparinux were added in vitro to whole blood taken from eight volunteers. The blood samples mixed with the various amounts of fondaparinux were analyzed using the Sonoclot. The whole-blood activated partial thromboplastin time with the Hemochron Jr (ITC, Edison, New Jersey, USA) was used as the reference coagulation analysis. All analyses were started expeditiously, within 30 s from sampling, and were performed at 37 degrees C. The values of the Sonoclot parameter clot rate, which measures the rate of fibrin formation, fibrin polymerization and platelet-fibrin interactions, were significantly correlated to increasing concentrations of fondaparinux (R = -0.90). The Sonoclot parameters of activated coagulation time, time to peak and clot retraction had weaker, but still significant, correlations to fondaparinux concentrations. At prophylactic doses (0.38 microg/ml blood) the clot rate decreased 15% compared with the initial unanticoagulated value, whereas at therapeutic doses (1.53 microg/ml blood) there was a 27% decrease. In conclusion, the Sonoclot parameter clot rate could be of clinical value to individualize the fondaparinux dosage, especially the higher, therapeutic, dosages.
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Maiti R, Agrawal NK, Dash D, Pandey BL. Effect of Pentoxifylline on inflammatory burden, oxidative stress and platelet aggregability in hypertensive type 2 diabetes mellitus patients. Vascul Pharmacol 2007; 47:118-24. [PMID: 17613279 DOI: 10.1016/j.vph.2007.05.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2007] [Indexed: 01/04/2023]
Abstract
OBJECTIVES Inflammation and oxidative stress are main culprits behind atherosclerosis in diabetes mellitus. This study explores the effect of add-on Pentoxifylline on inflammatory burden and oxidative stress in hypertensive diabetic patients. RESEARCH DESIGN AND METHODS 60 hypertensive type 2 diabetic, aged > or = 45 years were evaluated for anthropometry, clinical parameters, C-reactive protein, total leukocyte count, erythrocyte sedimentation rate, serum albumin, plasma malondialdehyde, blood reduced glutathione, platelet aggregation and clot retraction profile. With informed consent and randomization, Pentoxifylline (400 mg) was prescribed to 30 patients orally twice daily with meals as add-on therapy to the standard therapeutic regimen for one month. The particular parameters were repeated in 26 patients in control group and 25 patients in Pentoxifylline group who completed the follow up. The study was a randomized, open, add-on clinical trial with parallel controls. RESULTS At one-month follow-up, in the Pentoxifylline group, there was 20.9% decrease (p<0.001) in C-reactive protein, 18% reduction (p<0.001) in erythrocyte sedimentation rate, 11.1% reduction (p<0.001) in total leukocyte count and 5.8% increase (p=0.003) in serum albumin. Pentoxifylline showed 20.2% reduction in plasma malondialdehyde and 4.6% increase in blood reduced glutathione level. In therapeutic dose range, Pentoxifylline exerted a significant anti-aggregatory effect and a dose dependent decrease in clot retraction in-vitro but there was no significant change in ex-vivo clot retraction. The control group showed no statistically significant change in parameters assessed. CONCLUSION This study reveals improvements in inflammatory markers, oxidative stress and platelet-aggregation by Pentoxifylline, thus preventing atherosclerosis in diabetes mellitus.
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Affiliation(s)
- Rituparna Maiti
- Department of Pharmacology, Institute of Medical Sciences, Banaras Hindu University, Varanasi - 221005, India.
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Suzuki-Inoue K, Hughes CE, Inoue O, Kaneko M, Cuyun-Lira O, Takafuta T, Watson SP, Ozaki Y. Involvement of Src kinases and PLCgamma2 in clot retraction. Thromb Res 2006; 120:251-8. [PMID: 17055557 PMCID: PMC1884692 DOI: 10.1016/j.thromres.2006.09.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Revised: 09/08/2006] [Accepted: 09/12/2006] [Indexed: 11/18/2022]
Abstract
The integrin αIIbβ3 plays a critical role in mediating clot retraction by platelets which is important in vivo in consolidating thrombus formation. Actin–myosin interaction is essential for clot retraction. In the present study, we demonstrate that the structurally distinct Src kinase inhibitors, PP2 and PD173952, significantly reduced the rate of clot retraction, but did not prevent it reaching completion. This effect was accompanied by abolition of αIIbβ3-dependent protein tyrosine phosphorylation, including PLCγ2. A role for PLCγ2 in mediating clot retraction was demonstrated using PLCγ2-deficient murine platelets. Furthermore, platelet adhesion to fibrinogen leads to MLC phosphorylation through a pathway that is inhibited by PP2 and by the PLC inhibitor, U73122. These results demonstrate a partial role for Src kinase-dependent activation of PLCγ2 and MLC phosphorylation in mediating clot retraction downstream of integrin αIIbβ3.
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Affiliation(s)
- Katsue Suzuki-Inoue
- Department of Clinical and Laboratory Medicine, Faculty of Medicine, Yamanashi University, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan.
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Ballabeni V, Tognolini M, Bertoni S, Bruni R, Guerrini A, Rueda GM, Barocelli E. Antiplatelet and antithrombotic activities of essential oil from wild Ocotea quixos (Lam.) Kosterm. (Lauraceae) calices from Amazonian Ecuador. Pharmacol Res 2006; 55:23-30. [PMID: 17079160 DOI: 10.1016/j.phrs.2006.09.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Revised: 09/18/2006] [Accepted: 09/25/2006] [Indexed: 11/19/2022]
Abstract
Ocotea quixos essential oil was shown to possess significant inhibitory activity of platelet aggregation and clot retraction in rodent plasma. This study is aimed at fully characterizing the antiplatelet activity of the whole essential oil and its main components trans-cinnamaldehyde and methyl cinnamate also in human plasma, at investigating the mechanism underlying such activity and at evaluating the potential antithrombotic activity of subacute treatment of mice with Ocotea essential oil. In vitro Ocotea essential oil and trans-cinnamaldehyde inhibited arachidonic acid-, U46619-, ADP-, phorbol12-myristate13-alcetate-, collagen-induced platelet aggregation and thrombin-induced clot retraction in human and rodent plasma; Ocotea oil and trans-cinnamaldehyde competitively antagonized contractions induced by thromboxane A2 receptor agonist U46619 in rat isolated aortic ring (K(B) = 18 and 3.2 microg ml(-1), respectively). In vivo Ocotea oil, orally administered in a subacute treatment (30-100 mg kg(-1) day(-1) for 5 days) to mice, prevented acute thrombosis induced by collagen-epinephrine intravenous injection. This antithrombotic activity was not accompanied by pro-haemorragic side effect, as detected by the inactivity in bleeding test, thus showing a favourable safety profile compared to the conventional antiplatelet agent, acetylsalicylic acid. Present findings indicate that Ocotea essential oil possesses potent and safe antithrombotic activity attributable to its antiplatelet and vasorelaxant effects. The main constituent trans-cinnamaldehyde seems to be the primary responsible for this activity through a putative mechanism involving the inhibition of thromboxane A2 receptors.
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Affiliation(s)
- Vigilio Ballabeni
- Dip. di Scienze Farmacologiche, Biologiche e Chimiche Applicate, Università di Parma, Viale G.P.Usberti 27/A, 43100 Parma, Italy
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11
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Ratel D, Glazier G, Provençal M, Boivin D, Beaulieu E, Gingras D, Béliveau R. Direct-acting fibrinolytic enzymes in shark cartilage extract: potential therapeutic role in vascular disorders. Thromb Res 2005; 115:143-52. [PMID: 15567466 DOI: 10.1016/j.thromres.2004.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2004] [Revised: 07/14/2004] [Accepted: 07/18/2004] [Indexed: 11/17/2022]
Abstract
Fibrinogen and fibrin are molecules with overlapping roles in blood clotting, fibrinolysis, wound healing, inflammation, matrix and cellular interactions and neoplasia. There is currently much interest in the possible use of fibrinolytic agents in human therapeutics. In this study, we report the presence of fibrinolytic activities in shark cartilage extract (SCE). In vitro, SCE at 100 microg/ml completely degraded fibrin gel in an aprotinin-insensitive manner, suggesting a non-plasmin molecular nature. SCE was able to cleave all chains of fibrinogen and fibrin and the cleavage was completely inhibited by 1,10-phenanthroline, suggesting an essential role for metalloprotease(s) in this process. Using fibrinogen zymography, we show that SCE contains two plasmin-independent fibrinolytic activities and that these activities are correlated with the presence of 58 and 62 kDa proteases in the extract. SCE-fibrinolytic activities are inhibited by dithiothreitol, suggesting that disulfide bonds are necessary for the protease structure. Finally, using thromboelastography, SCE markedly induced retraction of human platelet-rich plasma (PRP) clot, this process being completely abolished by 1,10-phenanthroline. These data suggest the presence of novel non-plasmin fibrinolytic activities within SCE. This extract may thus represent a potential source of new therapeutic molecules to prevent and treat vaso-occlusive and thromboembolic disorders.
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Affiliation(s)
- David Ratel
- Laboratoire de Médecine Moléculaire Ste-Justine-UQAM, Centre de Cancérologie Charles-Bruneau, Hôpital Ste-Justine et Université du Québec à Montréal, 3175 Chemin Côte-Ste-Catherine, Montréal, QC, Canada H3T 1C5
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12
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Abstract
The plasma membrane Ca(2+)-ATPase (PMCA) plays an essential role in maintaining low cytosolic Ca2+ in platelets. Recently we demonstrated that PMCA is recruited to the cytoskeleton by interacting with PDZ domains. In the present study we determined the subcellular localization of PMCA using immunofluorescence microscopy. In resting platelets PMCA was distributed over the entire plasma membrane. Upon activation with thrombin, PMCA was found in filopodia adjacent to the actin cytoskeleton. PMCA translocation to filopodia was prevented by a peptide containing the last 10 residues of PMCA4b, the predominate isoform of PMCA in platelets, which contains a known PDZ domain-binding motif and was previously shown to block association of PMCA with the cytoskeleton. Incorporation of the PMCA C-terminal peptide did not affect the rate or extent of platelet aggregation, but significantly enhanced the rate of clot retraction. These results show that PMCA association with the cytoskeleton during platelet activation results in translocation of this Ca(2+)-pump to filopodia and that this association may affect later stages of platelet activation. The consequence of PMCA translocation to filopodia is likely a reduction in the local concentration of free Ca2+ in these structures resulting in regulation of the rate of clot retraction.
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Affiliation(s)
- William L Dean
- Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, Kentucky 40292, USA.
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13
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Carr ME, Angchaisuksiri P, Carr SL, Martin EJ. Effect of non-heparin thrombin antagonists on thrombin generation, platelet function, and clot structure in whole blood. Cell Biochem Biophys 2004; 39:89-99. [PMID: 14515016 DOI: 10.1385/cbb:39:2:89] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Platelet contractile force (PCF), which is absent in blood obtained during cardiopulmonary bypass, significantly recovers after protamine sulfate administration. In vitro studies reveal this effect to be primarily caused by heparin. Because many of heparin's effects are mediated by suppression of thrombin generation and activity, this study assessed the influence of thrombin inhibition on PCF. The effects of natural and synthetic antithrombins were measured. Clots were formed by the addition of batroxobin (0.21 microg/mL) to whole blood (platelet count 200,000/microL). Force development was measured from the moment of batroxobin addition. After 1200 s of clotting, purified antithrombin III (22 microM) reduced PCF by 74%. Thrombomodulin (0.014 microM) reduced PCF by 60%. At 0.040 microM, PCF was reduced by 82% (6.5-1.2 Kdynes). Hirudin decreased PCF in a dose-dependent fashion, with complete suppression at concentrations > or = 0.30 microM. At concentrations between 0.04 and 0.29 microM, Lepirudin (Refludan, a recombinant therapeutic hirudin) produced dose-dependent delay and suppression of PCF. Above 0.29 microM Lepirudin, PCF was totally suppressed. At 1.60 microM, bivalirudin (a synthetic, 20 amino acid peptide) delayed and reduced PCF by 50%. At 6.40 micro;M, PCF was completely suppressed. Although 20 microM of P-PACK II (d-Phenylalanyl-L-Phenylalanylarginine- chloro-methyl ketone 2 HCl) had little effect, 40 microM delayed onset of force development from 300 to 600 s and reduced PCF at 1200 s from 5.2 to 3.3 Kdynes. At 120 microM, force development was totally suppressed. Four micromol Thromstop (BNas-Gly-(pAM)Phe-Pip) delayed force development by greater than 800 s and PCF at 1200 s was reduced by 70%. At 0.20 microM, Argatroban (a synthetic polypeptide direct thrombin antagonist) delayed onset of PCF from 300 to 540 s and decreased PCF by 40%. At a concentration of 0.40 microM and above, Argatroban totally suppressed PCF. These results indicate that some of the antiplatelet effects of heparin are the result of thrombin inhibition and that low-level thrombin generation is essential for clot retraction. The sensitivity of PCF to the presence of thrombin may permit monitoring of antithrombin agents via this assay.
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Affiliation(s)
- Marcus E Carr
- Department of Medicine, Medical College of Virginia, Virginia Commonwealth University, and Richmond Veterans Administration Medical Center, Richmond, VA 23298-0230, USA.
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14
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Carr ME, Martin EJ, Kuhn JG, Seremetis SV. Effects of recombinant factor VIIa on platelet function and clot structure in blood with deficient prothrombin conversion. Thromb Haemost 2003; 89:803-11. [PMID: 12719776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
While recombinant factor VIIa (rFVIIa) shows promise as a broad-spectrum hemostatic agent, questions remain regarding the most appropriate dose and the best way to monitor its effects. In this study we tested the sensitivity of a thrombin dependent platelet assay, platelet contractile force, to the effects of rFVIIa in normal, factor-deficient, and inhibitor-containing blood samples. Dose dependent effects of rFVIIa on platelet contractile force (PCF) and clot elastic modulus (CEM) were measured in all blood samples. rFVIIa minimally affected PCF and CEM in normal blood clotted with thrombin or batroxobin. While rFVIIa minimally altered PCF and CEM in factor VIII (FVIII) deficient blood clotted with thrombin, rFVIIa increased PCF and CEM and shortened the lag phase in a dose dependent manner in batroxobin-induced clots. The effects of rFVIIa in factor IX (FIX) deficient blood mirrored the effects seen in FVIII deficient samples. Whether clotted with thrombin or batroxobin, baseline PCF and CEM were abnormally low in FVIII deficient samples containing FVIII inhibitors. In such samples, rFVIIa caused dose dependent improvement of PCF, CEM, and lag phases. In one patient with a spontaneous inhibitor, rFVIIa caused dose dependent increases in PCF and CEM in blood clotted with either enzyme. rFVIIa corrects the deficient thrombin generation seen in FVIII and FIX deficiency, and in blood containing FVIII inhibitors. As a consequence, platelet function is improved and clot structure is enhanced. Platelet contractile force and clot elastic modulus measurements are sensitive to the dose dependent effects of rFVIIa.
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Affiliation(s)
- Marcus E Carr
- Coagulation Special Studies Laboratory, Department of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298-0230, USA.
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15
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Massini P, Lüscher EF. Some effects of ionophores for divalent cations on blood platelets. Comparison with the effects of thrombin. Biochim Biophys Acta 1974; 372:109-21. [PMID: 4473225 DOI: 10.1016/0304-4165(74)90077-4] [Citation(s) in RCA: 112] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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