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Lee RH, Kawano T, Grover SP, Bharathi V, Martinez D, Cowley DO, Mackman N, Bergmeier W, Antoniak S. Genetic deletion of platelet PAR4 results in reduced thrombosis and impaired hemostatic plug stability. J Thromb Haemost 2022; 20:422-433. [PMID: 34689407 PMCID: PMC8792346 DOI: 10.1111/jth.15569] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND Protease-activated receptor 4 (PAR4) is expressed by a wide variety of cells, including megakaryocytes/platelets, immune cells, cardiomyocytes, and lung epithelial cells. It is the only functional thrombin receptor on murine platelets. A global deficiency of PAR4 is associated with impaired hemostasis and reduced thrombosis. OBJECTIVE We aimed to generate a mouse line with a megakaryocyte/platelet-specific deletion of PAR4 (PAR4fl/fl ;PF4Cre+ ) and use the mouse line to investigate the role of platelet PAR4 in hemostasis and thrombosis in mice. METHODS Platelets from PAR4fl/fl ;PF4Cre+ were characterized in vitro. Arterial and venous thrombosis was analyzed. Hemostatic plug formation was analyzed using a saphenous vein laser injury model in mice with global or megakaryocyte/platelet-specific deletion of PAR4 or wild-type mice treated with thrombin or glycoprotein VI (GPVI) inhibitors. RESULTS PAR4fl/fl ;PF4Cre+ platelets were unresponsive to thrombin or specific PAR4 stimulation but not to other agonists. PAR4-/- and PAR4fl/fl ;PF4Cre+ mice both exhibited a similar reduction in arterial thrombosis compared to their respective controls. More importantly, we show for the first time that platelet PAR4 is critical for venous thrombosis in mice. In addition, PAR4-/- mice and PAR4fl/fl ;PF4Cre+ mice exhibited a similar impairment in hemostatic plug stability in a saphenous vein laser injury model. Inhibition of thrombin in wild-type mice gave a similar phenotype. Combined PAR4 deficiency on platelets with GPVI inhibition did not impair hemostatic plug formation but further reduced plug stability. CONCLUSION We generated a novel PAR4fl/fl ;PF4Cre+ mouse line. We used this mouse line to show that PAR4 signaling in platelets is critical for arterial and venous thrombosis and hemostatic plug stability.
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Affiliation(s)
- Robert H. Lee
- UNC Blood Research Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Tomohiro Kawano
- UNC Blood Research Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Steven P. Grover
- UNC Blood Research Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Vanthana Bharathi
- UNC Blood Research Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - David Martinez
- UNC Blood Research Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Dale O. Cowley
- UNC Animal Models Core, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Nigel Mackman
- UNC Blood Research Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Division of Hematology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Wolfgang Bergmeier
- UNC Blood Research Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Silvio Antoniak
- UNC Blood Research Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Yu X, Li S, Zhu X, Kong Y. Inhibitors of protease activated receptor 4 (PAR4): a review of recent patents (2013-2021). Expert Opin Ther Pat 2022; 32:153-170. [PMID: 35081321 DOI: 10.1080/13543776.2022.2034786] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Protease-activated receptor 4 (PAR4), belonging to a subfamily of G-protein-coupled receptors (GPCR), is expressed on the surface of Human platelets, and the activation of it can lead to platelets aggregation. Studies demonstrated that PAR4 inhibition protect mice from arterial/arteriolar thrombosis, pulmonary embolism and cerebral infarct, while do not affect the haemostatic responses integrity. Therefore, PAR4 has been a promising target for the development of anti-thrombotic agents. AREAS COVERED This review covers recent patents and literature on PAR4 and their application published between 2013 and 2021. EXPERT OPINION PAR4 is a promising anti-thrombotic target and PAR4 inhibitors are important biologically active compounds for the treatment of thrombosis. Most the recent patents and literature focus on PAR4 selective inhibitors, and BMS-986120 and BMS-986141, which were developed by BMS, have entered clinical trials. With the deep understanding of the crystal structures and biological functions of PAR4, we believe that many other novel types of molecules targeting PAR4 would enter the clinical studies or the market.
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Affiliation(s)
- Xiangying Yu
- School of Life & Technology, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Shanshan Li
- Institute of Medicinal & Chemistry, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Xiong Zhu
- Institute of Medicinal & Chemistry, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Yi Kong
- School of Life & Technology, China Pharmaceutical University, Nanjing, 210009, PR China
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3
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Marcinczyk N, Misztal T, Gromotowicz-Poplawska A, Zebrowska A, Rusak T, Radziwon P, Chabielska E. Utility of Platelet Endothelial Cell Adhesion Molecule 1 in the Platelet Activity Assessment in Mouse and Human Blood. Int J Mol Sci 2021; 22:ijms22179611. [PMID: 34502520 PMCID: PMC8431756 DOI: 10.3390/ijms22179611] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/02/2021] [Accepted: 09/03/2021] [Indexed: 12/21/2022] Open
Abstract
In our previous study, we introduced the platelet endothelial cell adhesion molecule 1 (PECAM-1)/thrombus ratio, which is a parameter indicating the proportion of PECAM-1 in laser-induced thrombi in mice. Because PECAM-1 is an antithrombotic molecule, the higher the PECAM-1/thrombus ratio, the less activated the platelets. In this study, we used an extracorporeal model of thrombosis (flow chamber model) to verify its usefulness in the assessment of the PECAM-1/thrombus ratio in animal and human studies. Using the lipopolysaccharide (LPS)-induced inflammation model, we also evaluated whether the PECAM-1/thrombus ratio determined in the flow chamber (without endothelium) differed from that calculated in laser-induced thrombosis (with endothelium). We observed that acetylsalicylic acid (ASA) decreased the area of the thrombus while increasing the PECAM-1/thrombus ratio in healthy mice and humans in a dose-dependent manner. In LPS-treated mice, the PECAM-1/thrombus ratio decreased as the dose of ASA increased in both thrombosis models, but the direction of change in the thrombus area was inconsistent. Our study demonstrates that the PECAM-1/thrombus ratio can more accurately describe the platelet activation status than commonly used parameters such as the thrombus area, and, hence, it can be used in both human and animal studies.
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Affiliation(s)
- Natalia Marcinczyk
- Department of Biopharmacy, Medical University of Bialystok, 15-222 Bialystok, Poland; (A.G.-P.); (E.C.)
- Correspondence: ; Tel.: +48-857-485-607
| | - Tomasz Misztal
- Department of Physical Chemistry, Medical University of Bialystok, 15-089 Bialystok, Poland; (T.M.); (T.R.)
| | | | - Agnieszka Zebrowska
- Regional Centre for Transfusion Medicine, 15-950 Bialystok, Poland; (A.Z.); (P.R.)
| | - Tomasz Rusak
- Department of Physical Chemistry, Medical University of Bialystok, 15-089 Bialystok, Poland; (T.M.); (T.R.)
| | - Piotr Radziwon
- Regional Centre for Transfusion Medicine, 15-950 Bialystok, Poland; (A.Z.); (P.R.)
- Department of Haematology, Medical University of Bialystok, 15-276 Bialystok, Poland
| | - Ewa Chabielska
- Department of Biopharmacy, Medical University of Bialystok, 15-222 Bialystok, Poland; (A.G.-P.); (E.C.)
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4
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Selvadurai MV, Moon MJ, Mountford SJ, Ma X, Zheng Z, Jennings IG, Setiabakti NM, Iman RP, Brazilek RJ, Z Abidin NA, Chicanne G, Severin S, Nicholls AJ, Wong CHY, Rinckel JY, Eckly A, Gachet C, Nesbitt WS, Thompson PE, Hamilton JR. Disrupting the platelet internal membrane via PI3KC2α inhibition impairs thrombosis independently of canonical platelet activation. Sci Transl Med 2021; 12:12/553/eaar8430. [PMID: 32718993 DOI: 10.1126/scitranslmed.aar8430] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/12/2020] [Accepted: 06/05/2020] [Indexed: 12/17/2022]
Abstract
Arterial thrombosis causes heart attacks and most strokes and is the most common cause of death in the world. Platelets are the cells that form arterial thrombi, and antiplatelet drugs are the mainstay of heart attack and stroke prevention. Yet, current drugs have limited efficacy, preventing fewer than 25% of lethal cardiovascular events without clinically relevant effects on bleeding. The key limitation on the ability of all current drugs to impair thrombosis without causing bleeding is that they block global platelet activation, thereby indiscriminately preventing platelet function in hemostasis and thrombosis. Here, we identify an approach with the potential to overcome this limitation by preventing platelet function independently of canonical platelet activation and in a manner that appears specifically relevant in the setting of thrombosis. Genetic or pharmacological targeting of the class II phosphoinositide 3-kinase (PI3KC2α) dilates the internal membrane reserve of platelets but does not affect activation-dependent platelet function in standard tests. Despite this, inhibition of PI3KC2α is potently antithrombotic in human blood ex vivo and mice in vivo and does not affect hemostasis. Mechanistic studies reveal this antithrombotic effect to be the result of impaired platelet adhesion driven by pronounced hemodynamic shear stress gradients. These findings demonstrate an important role for PI3KC2α in regulating platelet structure and function via a membrane-dependent mechanism and suggest that drugs targeting the platelet internal membrane may be a suitable approach for antithrombotic therapies with an improved therapeutic window.
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Affiliation(s)
- Maria V Selvadurai
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia
| | - Mitchell J Moon
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia
| | - Simon J Mountford
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Xiao Ma
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Zhaohua Zheng
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Ian G Jennings
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Natasha M Setiabakti
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia.,Faculty of Medicine, Universitas Indonesia, Salemba, Jakarta 10430, Indonesia
| | - Rizani P Iman
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia.,Faculty of Medicine, Universitas Indonesia, Salemba, Jakarta 10430, Indonesia
| | - Rose J Brazilek
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia
| | - Nurul Aisha Z Abidin
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia
| | - Gaëtan Chicanne
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm U1048, Université Toulouse III, 31432 Toulouse CEDEX 4, France
| | - Sonia Severin
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm U1048, Université Toulouse III, 31432 Toulouse CEDEX 4, France
| | - Alyce J Nicholls
- Centre for Inflammatory Diseases, Department of Medicine, Monash Medical Centre, Monash University, Clayton, VIC 3800, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, Monash Medical Centre, Monash University, Clayton, VIC 3800, Australia
| | - Jean-Yves Rinckel
- Université de Strasbourg, INSERM, EFS Grand Est, BPPS UMR-S 1255, FMTS, F-67000 Strasbourg, France
| | - Anita Eckly
- Université de Strasbourg, INSERM, EFS Grand Est, BPPS UMR-S 1255, FMTS, F-67000 Strasbourg, France
| | - Christian Gachet
- Université de Strasbourg, INSERM, EFS Grand Est, BPPS UMR-S 1255, FMTS, F-67000 Strasbourg, France
| | - Warwick S Nesbitt
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia.,Microplatforms Research Group, School of Engineering, RMIT University, Melbourne, VIC 3000, Australia
| | - Philip E Thompson
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Justin R Hamilton
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia.
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5
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New approaches for the assessment of platelet activation status in thrombus under flow condition using confocal microscopy. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2019; 393:727-738. [PMID: 31834466 DOI: 10.1007/s00210-019-01789-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 12/03/2019] [Indexed: 10/25/2022]
Abstract
The goal of the study was the assessment of heterogeneous platelet activation status in thrombus. In a ferric(III) chloride (FeCl3) thrombosis (intravital) model of C57BL/6 J mice, the area of irreversibly activated (phosphatidylserine (PS)-positive) platelets was assessed after 1-s exposure of a vessel to FeCl3. In a laser-induced thrombosis (intravital) model of GFP mice, the area of the thrombus composed of PS-negative platelets was evaluated. The ratio of the area of PECAM-1 to the area of the thrombus was used as a marker to assess the activity of PS-negative platelets. In the in vitro flow chamber model, the thrombus area (PS-negative and PS-positive platelets) and the platelet activation index (ratio of the area of PS-positive platelets to the area of thrombus) were determined. To assess platelet activation status with these models, acetylsalicylic acid (ASA) and iloprost (Ilo) were used. In the FeCl3 thrombosis, ASA (10 mg/kg, 100 mg/kg) decreased the area of PS-positive platelets. In the laser thrombosis, ASA (10 mg/kg) decreased the thrombus area, but the decrease in platelet activity was evident even at 3 mg/kg by an increased PECAM-1/thrombus ratio. In the flow chamber, ASA (0.02 mg/ml, 0.2 mg/ml) equally decreased the platelet activation index, whereas only at 0.2 mg/ml, it decreased the thrombus area. Ilo (3.6 ng/ml, 36 ng/ml) decreased the thrombus area but at 36 ng/ml increased the platelet activation index. We showed that intravital models and flow chamber provide a detailed assessment of platelet activation status and the mechanism of drug action.
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6
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French SL, Hamilton JR. Drugs targeting protease-activated receptor-4 improve the anti-thrombotic therapeutic window. ANNALS OF TRANSLATIONAL MEDICINE 2017; 5:464. [PMID: 29285497 DOI: 10.21037/atm.2017.09.10] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Shauna L French
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - Justin R Hamilton
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
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7
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French SL, Hamilton JR. Perinatal lethality of Par4 -/- mice delivered by primiparous dams reveals spontaneous bleeding in mice without platelet thrombin receptor function. Platelets 2017; 29:196-198. [PMID: 28960148 DOI: 10.1080/09537104.2017.1349310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Protease-activated receptor 4 (PAR4) is a cell surface G protein-coupled receptor for serine proteases, such as thrombin. Par4-/- mice have platelets that are unresponsive to thrombin and thereby allow examination of the importance of thrombin-induced platelet activation in (patho)physiology. Par4-/- mice are protected against arterial thrombosis but show no evidence of spontaneous bleeding. This contrasts with the bleeding experienced by mice with marked thrombocytopenia, such as those with genetic deficiency of the transcription factor, nuclear factor erythroid 2 (Nfe2-/-), that have high rates of perinatal death due to hemorrhage. Given this discrepancy in spontaneous perinatal bleeding between mice without platelets and those without thrombin-induced platelet activation mechanisms, we examined in detail the immediate postnatal survival of Par4-/- pups. We observed significant postpartum loss of Par4-/- pups derived from Par4+/- intercrosses that was restricted to a dam's first litter; only 9% of surviving pups genotyped as Par4-/- in first litters and this normalized from the second litter onward (26%). A similar perinatal lethality in pups delivered by primiparous dams occurred in mice lacking platelets (Nfe2-/-; 10%) but not in those lacking fibrinogen (Fga-/-; 26%). These data,, provide the first evidence of spontaneous bleeding in Par4-/- mice, suggest that a dam's first litter provides a greater hemostatic challenge than subsequent litters, and uncovers an important role for platelets-and more specifically thrombin-induced platelet activation-in hemostasis during these more traumatic births.
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Affiliation(s)
- Shauna L French
- a Australian Centre for Blood Diseases, Monash University , Melbourne , Australia
| | - Justin R Hamilton
- a Australian Centre for Blood Diseases, Monash University , Melbourne , Australia
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8
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Yuan Y, Alwis I, Wu MCL, Kaplan Z, Ashworth K, Bark D, Pham A, Mcfadyen J, Schoenwaelder SM, Josefsson EC, Kile BT, Jackson SP. Neutrophil macroaggregates promote widespread pulmonary thrombosis after gut ischemia. Sci Transl Med 2017; 9:eaam5861. [PMID: 28954929 DOI: 10.1126/scitranslmed.aam5861] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 05/02/2017] [Accepted: 08/21/2017] [Indexed: 11/02/2022]
Abstract
Gut ischemia is common in critically ill patients, promoting thrombosis and inflammation in distant organs. The mechanisms linking hemodynamic changes in the gut to remote organ thrombosis remain ill-defined. We demonstrate that gut ischemia in the mouse induces a distinct pulmonary thrombotic disorder triggered by neutrophil macroaggregates. These neutrophil aggregates lead to widespread occlusion of pulmonary arteries, veins, and the microvasculature. A similar pulmonary neutrophil-rich thrombotic response occurred in humans with the acute respiratory distress syndrome. Intravital microscopy during gut ischemia-reperfusion injury revealed that rolling neutrophils extract large membrane fragments from remnant dying platelets in multiple organs. These platelet fragments bridge adjacent neutrophils to facilitate macroaggregation. Platelet-specific deletion of cyclophilin D, a mitochondrial regulator of cell necrosis, prevented neutrophil macroaggregation and pulmonary thrombosis. Our studies demonstrate the existence of a distinct pulmonary thrombotic disorder triggered by dying platelets and neutrophil macroaggregates. Therapeutic targeting of platelet death pathways may reduce pulmonary thrombosis in critically ill patients.
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Affiliation(s)
- Yuping Yuan
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
- Heart Research Institute, Newtown, New South Wales 2042, Australia
- Charles Perkins Centre, University of Sydney, New South Wales 2006, Australia
| | - Imala Alwis
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
- Heart Research Institute, Newtown, New South Wales 2042, Australia
- Charles Perkins Centre, University of Sydney, New South Wales 2006, Australia
| | - Mike C L Wu
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
- Heart Research Institute, Newtown, New South Wales 2042, Australia
- Charles Perkins Centre, University of Sydney, New South Wales 2006, Australia
| | - Zane Kaplan
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
| | - Katrina Ashworth
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
| | - David Bark
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
| | - Alan Pham
- Department of Anatomical Pathology, Alfred Hospital, Prahran, Victoria 3181, Australia
| | - James Mcfadyen
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
| | - Simone M Schoenwaelder
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
- Heart Research Institute, Newtown, New South Wales 2042, Australia
| | - Emma C Josefsson
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Benjamin T Kile
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3168, Australia
| | - Shaun P Jackson
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia.
- Heart Research Institute, Newtown, New South Wales 2042, Australia
- Charles Perkins Centre, University of Sydney, New South Wales 2006, Australia
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
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French SL, Paramitha AC, Moon MJ, Dickins RA, Hamilton JR. Humanizing the Protease-Activated Receptor (PAR) Expression Profile in Mouse Platelets by Knocking PAR1 into the Par3 Locus Reveals PAR1 Expression Is Not Tolerated in Mouse Platelets. PLoS One 2016; 11:e0165565. [PMID: 27788223 PMCID: PMC5082849 DOI: 10.1371/journal.pone.0165565] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 10/13/2016] [Indexed: 11/29/2022] Open
Abstract
Anti-platelet drugs are the mainstay of pharmacotherapy for heart attack and stroke prevention, yet improvements are continually sought. Thrombin is the most potent activator of platelets and targeting platelet thrombin receptors (protease-activated receptors; PARs) is an emerging anti-thrombotic approach. Humans express two PARs on their platelets–PAR1 and PAR4. The first PAR1 antagonist was recently approved for clinical use and PAR4 antagonists are in early clinical development. However, pre-clinical studies examining platelet PAR function are challenging because the platelets of non-primates do not accurately reflect the PAR expression profile of human platelets. Mice, for example, express Par3 and Par4. To address this limitation, we aimed to develop a genetically modified mouse that would express the same repertoire of platelet PARs as humans. Here, human PAR1 preceded by a lox-stop-lox was knocked into the mouse Par3 locus, and then expressed in a platelet-specific manner (hPAR1-KI mice). Despite correct targeting and the predicted loss of Par3 expression and function in platelets from hPAR1-KI mice, no PAR1 expression or function was detected. Specifically, PAR1 was not detected on the platelet surface nor internally by flow cytometry nor in whole cell lysates by Western blot, while a PAR1-activating peptide failed to induce platelet activation assessed by either aggregation or surface P-selectin expression. Platelets from hPAR1-KI mice did display significantly diminished responsiveness to thrombin stimulation in both assays, consistent with a Par3-/- phenotype. In contrast to the observations in hPAR1-KI mouse platelets, the PAR1 construct used here was successfully expressed in HEK293T cells. Together, these data suggest ectopic PAR1 expression is not tolerated in mouse platelets and indicate a different approach is required to develop a small animal model for the purpose of any future preclinical testing of PAR antagonists as anti-platelet drugs.
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Affiliation(s)
- Shauna L. French
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | | | - Mitchell J. Moon
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - Ross A. Dickins
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - Justin R. Hamilton
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
- * E-mail:
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10
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French SL, Arthur JF, Lee H, Nesbitt WS, Andrews RK, Gardiner EE, Hamilton JR. Inhibition of protease-activated receptor 4 impairs platelet procoagulant activity during thrombus formation in human blood. J Thromb Haemost 2016; 14:1642-54. [PMID: 26878340 DOI: 10.1111/jth.13293] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 01/26/2016] [Indexed: 01/11/2023]
Abstract
UNLABELLED Essentials The platelet thrombin receptor, PAR4, is an emerging anti-thrombotic drug target. We examined the anti-platelet & anti-thrombotic effects of PAR4 inhibition in human blood. PAR4 inhibition impaired platelet procoagulant activity in isolated cells and during thrombosis. Our study shows PAR4 is required for platelet procoagulant function & thrombosis in human blood. SUMMARY Background Thrombin-induced platelet activation is important for arterial thrombosis. Thrombin activates human platelets predominantly via protease-activated receptor (PAR)1 and PAR4. PAR1 has higher affinity for thrombin, and the first PAR1 antagonist, vorapaxar, was recently approved for use as an antiplatelet agent. However, vorapaxar is contraindicated in a significant number of patients, owing to adverse bleeding events. Consequently, there is renewed interest in the role of platelet PAR4 in the setting of thrombus formation. Objectives To determine the specific antiplatelet effects of inhibiting PAR4 function during thrombus formation in human whole blood. Methods and Results We developed a rabbit polyclonal antibody against the thrombin cleavage site of PAR4, and showed it to be a highly specific inhibitor of PAR4-mediated platelet function. This function-blocking anti-PAR4 antibody was used to probe for PAR4-dependent platelet functions in human isolated platelets in the absence and presence of concomitant PAR1 inhibition. The anti-PAR4 antibody alone was sufficient to abolish the sustained elevation of cytosolic calcium level and consequent phosphatidylserine exposure induced by thrombin, but did not significantly inhibit integrin αII b β3 activation, α-granule secretion, or aggregation. In accord with these in vitro experiments on isolated platelets, selective inhibition of PAR4, but not of PAR1, impaired thrombin activity (fluorescence resonance energy transfer-based thrombin sensor) and fibrin formation (anti-fibrin antibody) in an ex vivo whole blood flow thrombosis assay. Conclusions These findings demonstrate that PAR4 is required for platelet procoagulant function during thrombus formation in human blood, and suggest PAR4 inhibition as a potential target for the prevention of arterial thrombosis.
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Affiliation(s)
- S L French
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - J F Arthur
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - H Lee
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - W S Nesbitt
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
- Microplatforms Research Group, School of Engineering, RMIT University, Melbourne, Australia
| | - R K Andrews
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - E E Gardiner
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - J R Hamilton
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
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11
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Yeung J, Tourdot BE, Adili R, Green AR, Freedman CJ, Fernandez-Perez P, Yu J, Holman TR, Holinstat M. 12(S)-HETrE, a 12-Lipoxygenase Oxylipin of Dihomo-γ-Linolenic Acid, Inhibits Thrombosis via Gαs Signaling in Platelets. Arterioscler Thromb Vasc Biol 2016; 36:2068-77. [PMID: 27470510 DOI: 10.1161/atvbaha.116.308050] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 07/15/2016] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Dietary supplementation with polyunsaturated fatty acids has been widely used for primary and secondary prevention of cardiovascular disease in individuals at risk; however, the cardioprotective benefits of polyunsaturated fatty acids remain controversial because of lack of mechanistic and in vivo evidence. We present direct evidence that an omega-6 polyunsaturated fatty acid, dihomo-γ-linolenic acid (DGLA), exhibits in vivo cardioprotection through 12-lipoxygenase (12-LOX) oxidation of DGLA to its reduced oxidized lipid form, 12(S)-hydroxy-8Z,10E,14Z-eicosatrienoic acid (12(S)-HETrE), inhibiting platelet activation and thrombosis. APPROACH AND RESULTS DGLA inhibited ex vivo platelet aggregation and Rap1 activation in wild-type mice, but not in mice lacking 12-LOX expression (12-LOX(-/-)). Similarly, wild-type mice treated with DGLA were able to reduce thrombus growth (platelet and fibrin accumulation) after laser-induced injury of the arteriole of the cremaster muscle, but not 12-LOX(-/-) mice, supporting a 12-LOX requirement for mediating the inhibitory effects of DGLA on platelet-mediated thrombus formation. Platelet activation and thrombus formation were also suppressed when directly treated with 12(S)-HETrE. Importantly, 2 hemostatic models, tail bleeding and arteriole rupture of the cremaster muscle, showed no alteration in hemostasis after 12(S)-HETrE treatment. Finally, the mechanism for 12(S)-HETrE protection was shown to be mediated via a Gαs-linked G-protein-coupled receptor pathway in human platelets. CONCLUSIONS This study provides the direct evidence that an omega-6 polyunsaturated fatty acid, DGLA, inhibits injury-induced thrombosis through its 12-LOX oxylipin, 12(S)-HETrE, which strongly supports the potential cardioprotective benefits of DGLA supplementation through its regulation of platelet function. Furthermore, this is the first evidence of a 12-LOX oxylipin regulating platelet function in a Gs α subunit-linked G-protein-coupled receptor-dependent manner.
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Affiliation(s)
- Jennifer Yeung
- From the Department of Pharmacology (J.Y., B.E.T., R.A., M.H.) and Department of Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor; Cardeza Foundation for Hematological Research, Thomas Jefferson University, Philadelphia, PA (J.Y., B.E.T., R.A., P.F.-P., J.Y., M.H.); and Department of Chemistry and Biochemistry, University of California Santa Cruz (A.R.G., C.J.F., T.R.H.)
| | - Benjamin E Tourdot
- From the Department of Pharmacology (J.Y., B.E.T., R.A., M.H.) and Department of Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor; Cardeza Foundation for Hematological Research, Thomas Jefferson University, Philadelphia, PA (J.Y., B.E.T., R.A., P.F.-P., J.Y., M.H.); and Department of Chemistry and Biochemistry, University of California Santa Cruz (A.R.G., C.J.F., T.R.H.)
| | - Reheman Adili
- From the Department of Pharmacology (J.Y., B.E.T., R.A., M.H.) and Department of Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor; Cardeza Foundation for Hematological Research, Thomas Jefferson University, Philadelphia, PA (J.Y., B.E.T., R.A., P.F.-P., J.Y., M.H.); and Department of Chemistry and Biochemistry, University of California Santa Cruz (A.R.G., C.J.F., T.R.H.)
| | - Abigail R Green
- From the Department of Pharmacology (J.Y., B.E.T., R.A., M.H.) and Department of Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor; Cardeza Foundation for Hematological Research, Thomas Jefferson University, Philadelphia, PA (J.Y., B.E.T., R.A., P.F.-P., J.Y., M.H.); and Department of Chemistry and Biochemistry, University of California Santa Cruz (A.R.G., C.J.F., T.R.H.)
| | - Cody J Freedman
- From the Department of Pharmacology (J.Y., B.E.T., R.A., M.H.) and Department of Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor; Cardeza Foundation for Hematological Research, Thomas Jefferson University, Philadelphia, PA (J.Y., B.E.T., R.A., P.F.-P., J.Y., M.H.); and Department of Chemistry and Biochemistry, University of California Santa Cruz (A.R.G., C.J.F., T.R.H.)
| | - Pilar Fernandez-Perez
- From the Department of Pharmacology (J.Y., B.E.T., R.A., M.H.) and Department of Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor; Cardeza Foundation for Hematological Research, Thomas Jefferson University, Philadelphia, PA (J.Y., B.E.T., R.A., P.F.-P., J.Y., M.H.); and Department of Chemistry and Biochemistry, University of California Santa Cruz (A.R.G., C.J.F., T.R.H.)
| | - Johnny Yu
- From the Department of Pharmacology (J.Y., B.E.T., R.A., M.H.) and Department of Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor; Cardeza Foundation for Hematological Research, Thomas Jefferson University, Philadelphia, PA (J.Y., B.E.T., R.A., P.F.-P., J.Y., M.H.); and Department of Chemistry and Biochemistry, University of California Santa Cruz (A.R.G., C.J.F., T.R.H.)
| | - Theodore R Holman
- From the Department of Pharmacology (J.Y., B.E.T., R.A., M.H.) and Department of Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor; Cardeza Foundation for Hematological Research, Thomas Jefferson University, Philadelphia, PA (J.Y., B.E.T., R.A., P.F.-P., J.Y., M.H.); and Department of Chemistry and Biochemistry, University of California Santa Cruz (A.R.G., C.J.F., T.R.H.)
| | - Michael Holinstat
- From the Department of Pharmacology (J.Y., B.E.T., R.A., M.H.) and Department of Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor; Cardeza Foundation for Hematological Research, Thomas Jefferson University, Philadelphia, PA (J.Y., B.E.T., R.A., P.F.-P., J.Y., M.H.); and Department of Chemistry and Biochemistry, University of California Santa Cruz (A.R.G., C.J.F., T.R.H.).
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12
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French SL, Hamilton JR. Protease-activated receptor 4: from structure to function and back again. Br J Pharmacol 2016; 173:2952-65. [PMID: 26844674 DOI: 10.1111/bph.13455] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Revised: 01/22/2016] [Accepted: 01/29/2016] [Indexed: 12/21/2022] Open
Abstract
Protease-activated receptors are a family of four GPCRs (PAR1-PAR4) with a number of unique attributes. Nearly two and a half decades after the discovery of the first PAR, an antagonist targeting this receptor has been approved for human use. The first-in-class PAR1 antagonist, vorapaxar, was approved for use in the USA in 2014 for the prevention of thrombotic cardiovascular events in patients with a history of myocardial infarction or with peripheral arterial disease. These recent developments indicate the clinical potential of manipulating PAR function. While much work has been aimed at uncovering the function of PAR1 and, to a lesser extent, PAR2, comparatively little is known regarding the pharmacology and physiology of PAR3 and PAR4. Recent studies have begun to develop the pharmacological and genetic tools required to study PAR4 function in detail, and there is now emerging evidence for the function of PAR4 in disease settings. In this review, we detail the discovery, structure, pharmacology, physiological significance and therapeutic potential of PAR4. Linked Articles This article is part of a themed section on Molecular Pharmacology of G Protein-Coupled Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v173.20/issuetoc.
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Affiliation(s)
- Shauna L French
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - Justin R Hamilton
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia.
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Schaff M, Gachet C, Mangin PH. [Anti-platelets without a bleeding risk: novel targets and strategies]. Biol Aujourdhui 2016; 209:211-28. [PMID: 26820829 DOI: 10.1051/jbio/2015023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Indexed: 01/29/2023]
Abstract
Anti-platelet agents such as aspirin, clopidogrel and antagonists of integrin αIIbβ3 allowed to efficiently reduce morbidity and mortality associated with arterial thrombosis. A major limit of these drugs is that they increase the risk of bleeding. During the last few years, several innovative anti-thrombotic strategies with a potentially low bleeding risk were proposed. These approaches target the collagen receptor glycoprotein (GP) VI, the GPIb/von Willebrand factor axis, the thrombin receptor PAR-1, the activated form of integrin αIIbβ3 or the ADP receptor P2Y1. While an antagonist of PAR-1 was recently marketed, the clinical proofs of the efficiency and safety of the other agents remain to be established. This review evaluates these new anti-platelet approaches toward safer anti-thrombotic therapies.
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Affiliation(s)
- Mathieu Schaff
- Atherothrombosis and Vascular Biology Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Australie
| | - Christian Gachet
- UMR_S949, INSERM, Etablissement Français du Sang (EFS)-Alsace, Université de Strasbourg, Strasbourg, France
| | - Pierre Henri Mangin
- UMR_S949, INSERM, Etablissement Français du Sang (EFS)-Alsace, Université de Strasbourg, Strasbourg, France
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14
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Mountford JK, Petitjean C, Putra HWK, McCafferty JA, Setiabakti NM, Lee H, Tønnesen LL, McFadyen JD, Schoenwaelder SM, Eckly A, Gachet C, Ellis S, Voss AK, Dickins RA, Hamilton JR, Jackson SP. The class II PI 3-kinase, PI3KC2α, links platelet internal membrane structure to shear-dependent adhesive function. Nat Commun 2015; 6:6535. [PMID: 25779105 DOI: 10.1038/ncomms7535] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 02/05/2015] [Indexed: 12/29/2022] Open
Abstract
PI3KC2α is a broadly expressed lipid kinase with critical functions during embryonic development but poorly defined roles in adult physiology. Here we utilize multiple mouse genetic models to uncover a role for PI3KC2α in regulating the internal membrane reserve structure of megakaryocytes (demarcation membrane system) and platelets (open canalicular system) that results in dysregulated platelet adhesion under haemodynamic shear stress. Structural alterations in the platelet internal membrane lead to enhanced membrane tether formation that is associated with accelerated, yet highly unstable, thrombus formation in vitro and in vivo. Notably, agonist-induced 3-phosphorylated phosphoinositide production and cellular activation are normal in PI3KC2α-deficient platelets. These findings demonstrate an important role for PI3KC2α in regulating shear-dependent platelet adhesion via regulation of membrane structure, rather than acute signalling. These studies provide a link between the open canalicular system and platelet adhesive function that has relevance to the primary haemostatic and prothrombotic function of platelets.
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Affiliation(s)
- Jessica K Mountford
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Claire Petitjean
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Harun W Kusuma Putra
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Jonathan A McCafferty
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Natasha M Setiabakti
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Hannah Lee
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Lotte L Tønnesen
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - James D McFadyen
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Simone M Schoenwaelder
- 1] Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia [2] The Heart Research Institute and Charles Perkins Centre, The University of Sydney, Newtown 2050, Australia
| | - Anita Eckly
- Unité mixte de recherche S949 Institut National de la Santé et de la Recherche Médicale, Université de Strasbourg, Etablissement Français du Sang-Alsace 67000, Strasbourg, France
| | - Christian Gachet
- Unité mixte de recherche S949 Institut National de la Santé et de la Recherche Médicale, Université de Strasbourg, Etablissement Français du Sang-Alsace 67000, Strasbourg, France
| | - Sarah Ellis
- Sir Peter MacCallum Department of Oncology, Peter MacCallum Cancer Centre and The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Anne K Voss
- 1] Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Ross A Dickins
- 1] Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Justin R Hamilton
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Shaun P Jackson
- 1] Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia [2] The Heart Research Institute and Charles Perkins Centre, The University of Sydney, Newtown 2050, Australia [3] Department of Molecular and Experimental Medicine, The Scripps Research Institute, San Diego, CA 92037, USA
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15
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French SL, Arthur JF, Tran HA, Hamilton JR. Approval of the first protease-activated receptor antagonist: Rationale, development, significance, and considerations of a novel anti-platelet agent. Blood Rev 2014; 29:179-89. [PMID: 25467961 DOI: 10.1016/j.blre.2014.10.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 10/27/2014] [Indexed: 12/12/2022]
Abstract
Twenty-three years after the discovery of the first thrombin receptor, now known as protease-activated receptor 1 (PAR1), the first drug targeting this receptor is available for human use. The PAR1 inhibitor, vorapaxar (Zontivity, MSD), was recently approved by the FDA for use in the USA for the prevention of thrombotic cardiovascular events in patients with a history of myocardial infarction or peripheral artery disease. In this review, we detail the rationale, development, as well as the clinical significance and considerations of vorapaxar, the original PAR antagonist and the latest anti-platelet agent in the pharmaco-armoury against arterial thrombosis.
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Affiliation(s)
- Shauna L French
- Australian Centre for Blood Diseases, Monash University, Melbourne, Victoria, Australia; Department of Clinical Haematology, Monash University, Melbourne, Victoria, Australia
| | - Jane F Arthur
- Australian Centre for Blood Diseases, Monash University, Melbourne, Victoria, Australia; Department of Clinical Haematology, Monash University, Melbourne, Victoria, Australia
| | - Huyen A Tran
- Australian Centre for Blood Diseases, Monash University, Melbourne, Victoria, Australia; Department of Clinical Haematology, Monash University, Melbourne, Victoria, Australia
| | - Justin R Hamilton
- Australian Centre for Blood Diseases, Monash University, Melbourne, Victoria, Australia; Department of Clinical Haematology, Monash University, Melbourne, Victoria, Australia.
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16
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Hosokawa K, Ohnishi T, Miura N, Sameshima H, Koide T, Tanaka KA, Maruyama I. Antithrombotic effects of PAR1 and PAR4 antagonists evaluated under flow and static conditions. Thromb Res 2014; 133:66-72. [DOI: 10.1016/j.thromres.2013.10.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 10/09/2013] [Accepted: 10/28/2013] [Indexed: 01/22/2023]
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17
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Ungerer M, Münch G. Novel antiplatelet drugs in clinical development. Thromb Haemost 2013; 110:868-75. [PMID: 24108565 DOI: 10.1160/th13-02-0084] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 09/04/2013] [Indexed: 01/13/2023]
Abstract
The clinical value of antiplatelet compounds strongly depends on the benefit-risk balance between their anti-thrombotic effects and the bleeding risk they incur. This ratio is especially important in the treatment of cerebro-vascular disease. Several novel compounds in clinical development hold promise to improve this benefit-risk ratio.
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Affiliation(s)
- M Ungerer
- M. Ungerer, Advancecor GmbH, Fraunhofer Str. 17, 82152 Martinsried, Germany, E-mail:
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