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Verdier H, Thomas P, Batista J, Kempster C, McKinney H, Gleadall N, Danesh J, Mumford A, Heemskerk JWM, Ouwehand WH, Downes K, Astle WJ, Turro E. A signature of platelet reactivity in CBC scattergrams reveals genetic predictors of thrombotic disease risk. Blood 2023; 142:1895-1908. [PMID: 37647652 PMCID: PMC10733829 DOI: 10.1182/blood.2023021100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/27/2023] [Accepted: 08/18/2023] [Indexed: 09/01/2023] Open
Abstract
Genetic studies of platelet reactivity (PR) phenotypes may identify novel antiplatelet drug targets. However, such studies have been limited by small sample sizes (n < 5000) because of the complexity of measuring PR. We trained a model to predict PR from complete blood count (CBC) scattergrams. A genome-wide association study of this phenotype in 29 806 blood donors identified 21 distinct associations implicating 20 genes, of which 6 have been identified previously. The effect size estimates were significantly correlated with estimates from a study of flow cytometry-measured PR and a study of a phenotype of in vitro thrombus formation. A genetic score of PR built from the 21 variants was associated with the incidence rates of myocardial infarction and pulmonary embolism. Mendelian randomization analyses showed that PR was causally associated with the risks of coronary artery disease, stroke, and venous thromboembolism. Our approach provides a blueprint for using phenotype imputation to study the determinants of hard-to-measure but biologically important hematological traits.
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Affiliation(s)
- Hippolyte Verdier
- Institut Pasteur, CNRS UMR 3751, Decision and Bayesian Computation, Université Paris Cité, Paris, France
| | - Patrick Thomas
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Joana Batista
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Carly Kempster
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Harriet McKinney
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Nicholas Gleadall
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - John Danesh
- British Heart Foundation Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom
- Victor Phillip Dahdaleh Heart and Lung Research Institute, University of Cambridge, Cambridge, United Kingdom
- British Heart Foundation Centre of Research Excellence, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
- Health Data Research UK Cambridge, Wellcome Genome Campus and University of Cambridge, Cambridge, United Kingdom
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Andrew Mumford
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
- South West National Health Service Genomic Medicine Service Alliance, Bristol, United Kingdom
| | | | - Willem H. Ouwehand
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Kate Downes
- Cambridge Genomics Laboratory, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - William J. Astle
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Medical Research Council Biostatistics Unit, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom
- National Institute for Health and Care Research Blood and Transplant Research Unit in Donor Health and Behaviour, University of Cambridge, Cambridge, United Kingdom
| | - Ernest Turro
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
- Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
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Belleville-Rolland T, Leuci A, Mansour A, Decouture B, Martin F, Poirault-Chassac S, Rouaud M, Guerineau H, Dizier B, Pidard D, Gaussem P, Bachelot-Loza C. Role of Membrane Lipid Rafts in MRP4 (ABCC4) Dependent Regulation of the cAMP Pathway in Blood Platelets. Thromb Haemost 2021; 121:1628-1636. [PMID: 33851387 DOI: 10.1055/a-1481-2663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND Platelet cytosolic cyclic adenosine monophosphate (cAMP) levels are balanced by synthesis, degradation, and efflux. Efflux can occur via multidrug resistant protein-4 (MRP4; ABCC4) present on dense granule and/or plasma membranes. As lipid rafts have been shown to interfere on cAMP homeostasis, we evaluated the relationships between the distribution and activity of MRP4 in lipid rafts and cAMP efflux. METHODS Platelet activation and cAMP homeostasis were analyzed in human and wild-type or MRP4-deleted mouse platelets in the presence of methyl-β-cyclodextrin (MßCD) to disrupt lipid rafts, and of activators of the cAMP signalling pathways. Human platelet MRP4 and effector proteins of the cAMP pathway were analyzed by immunoblots in lipid rafts isolated by differential centrifugation. RESULTS MßCD dose dependently inhibited human and mouse platelet aggregation without affecting per se cAMP levels. An additive inhibitory effect existed between the adenylate cyclase (AC) activator forskolin and MßCD that was accompanied by an overincrease of cAMP, and which was significantly enhanced upon MRP4 deletion. Finally, an efflux of cAMP out of resting platelets incubated with prostaglandin E1 (PGE1) was observed that was partly dependent on MRP4. Lipid rafts contained a small fraction (≈15%) of MRP4 and most of the inhibitory G-protein Gi, whereas Gs protein, AC3, and phosphodiesterases PDE2 and PDE3A were all present as only trace amounts. CONCLUSION Our results are in favour of part of MRP4 present at the platelet surface, including in lipid rafts. Lipid raft integrity is necessary for cAMP signalling regulation, although MRP4 and most players of cAMP homeostasis are essentially located outside rafts.
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Affiliation(s)
- Tiphaine Belleville-Rolland
- Service d'hématologie biologique, AH-HP, Hopital Européen Georges Pompidou, Paris, France
- Université de Paris, Innovative Therapies in Haemostasis, INSERM U1140, Paris, France
| | - Alexandre Leuci
- Université de Paris, Innovative Therapies in Haemostasis, INSERM U1140, Paris, France
| | - Alexandre Mansour
- Université de Paris, Innovative Therapies in Haemostasis, INSERM U1140, Paris, France
| | - Benoit Decouture
- Université de Paris, Innovative Therapies in Haemostasis, INSERM U1140, Paris, France
| | - Fanny Martin
- Université de Paris, Innovative Therapies in Haemostasis, INSERM U1140, Paris, France
| | | | - Margot Rouaud
- Université de Paris, Innovative Therapies in Haemostasis, INSERM U1140, Paris, France
| | - Hippolyte Guerineau
- Université de Paris, Innovative Therapies in Haemostasis, INSERM U1140, Paris, France
| | - Blandine Dizier
- Université de Paris, Innovative Therapies in Haemostasis, INSERM U1140, Paris, France
| | - Dominique Pidard
- Université de Paris, Innovative Therapies in Haemostasis, INSERM U1140, Paris, France
| | - Pascale Gaussem
- Service d'hématologie biologique, AH-HP, Hopital Européen Georges Pompidou, Paris, France
- Université de Paris, Innovative Therapies in Haemostasis, INSERM U1140, Paris, France
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Soriano Jerez EM, Gibbins JM, Hughes CE. Targeting platelet inhibition receptors for novel therapies: PECAM-1 and G6b-B. Platelets 2021; 32:761-769. [PMID: 33646086 DOI: 10.1080/09537104.2021.1882668] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
While current oral antiplatelet therapies benefit many patients, they deregulate the hemostatic balance leaving patients at risk of systemic side-effects such as hemorrhage. Dual antiplatelet treatment is the standard approach, combining aspirin with P2Y12 blockers. These therapies mainly target autocrine activation mechanisms (TxA2, ADP) and, more recently, the use of thrombin or thrombin receptor antagonists have been added to the available approaches. Recent efforts to develop new classes of anti-platelet drugs have begun to focus on primary platelet activation pathways such as through the immunoreceptor tyrosine-based activation motif (ITAM)-containing collagen receptor GPVI/FcRγ-chain complex. There are already encouraging results from targeting GPVI, with reduced aggregation and smaller arterial thrombi, without major bleeding complications, likely due to overlapping activation signaling pathways with other receptors such as the GPIb-V-IX complex. An alternative approach to reduce platelet activation could be to inhibit this signaling pathway by targeting the inhibitory pathways intrinsic to platelets. Stimulation of endogenous negative modulators could provide more specific inhibition of platelet function, but is this feasible? In this review, we explore the potential of the two major platelet immunoreceptor tyrosine-based inhibitory motif (ITIM)-containing inhibitory receptors, G6b-B and PECAM-1, as antithrombotic targets.
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Affiliation(s)
- Eva M Soriano Jerez
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, UK.,Institute of Experimental Biomedicine, University Hospital Würzburg and Rudolf Virchow Center for Integrative and Translational Bioimaging, University of Würzburg, Würzburg, Germany
| | - Jonathan M Gibbins
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, UK
| | - Craig E Hughes
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, UK
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Platelets in Healthy and Disease States: From Biomarkers Discovery to Drug Targets Identification by Proteomics. Int J Mol Sci 2020; 21:ijms21124541. [PMID: 32630608 PMCID: PMC7352998 DOI: 10.3390/ijms21124541] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/15/2020] [Accepted: 06/24/2020] [Indexed: 12/16/2022] Open
Abstract
Platelets are a heterogeneous small anucleate blood cell population with a central role both in physiological haemostasis and in pathological states, spanning from thrombosis to inflammation, and cancer. Recent advances in proteomic studies provided additional important information concerning the platelet biology and the response of platelets to several pathophysiological pathways. Platelets circulate systemically and can be easily isolated from human samples, making proteomic application very interesting for characterizing the complexity of platelet functions in health and disease as well as for identifying and quantifying potential platelet proteins as biomarkers and novel antiplatelet therapeutic targets. To date, the highly dynamic protein content of platelets has been studied in resting and activated platelets, and several subproteomes have been characterized including platelet-derived microparticles, platelet granules, platelet releasates, platelet membrane proteins, and specific platelet post-translational modifications. In this review, a critical overview is provided on principal platelet proteomic studies focused on platelet biology from signaling to granules content, platelet proteome changes in several diseases, and the impact of drugs on platelet functions. Moreover, recent advances in quantitative platelet proteomics are discussed, emphasizing the importance of targeted quantification methods for more precise, robust and accurate quantification of selected proteins, which might be used as biomarkers for disease diagnosis, prognosis and therapy, and their strong clinical impact in the near future.
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Izquierdo I, Barrachina MN, Hermida-Nogueira L, Casas V, Eble JA, Carrascal M, Abián J, García Á. Platelet membrane lipid rafts protein composition varies following GPVI and CLEC-2 receptors activation. J Proteomics 2019; 195:88-97. [PMID: 30677554 DOI: 10.1016/j.jprot.2019.01.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/03/2019] [Accepted: 01/20/2019] [Indexed: 12/11/2022]
Abstract
Lipid rafts are membrane microdomains that have been proposed to play an important role in several platelet-signalling cascades, including those mediated by the receptors Glycoprotein VI (GPVI), and C-type lectin domain family 1 member B (CLEC-2), both involved in thrombus formation. We have performed a LC-MS/MS proteomic analysis of lipid rafts isolated from platelets activated through GPVI and CLEC-2 as well as from resting platelets. Our aim was to determine the magnitude of changes in lipid rafts protein composition and to elucidate the relevance of these alterations in platelet function. A number of relevant signalling proteins were found enriched in lipid rafts following platelet activation (such as the tyrosine protein kinases Fyn, Lyn and Yes; the G proteins G(i) and G(z); and cAMP protein kinase). Interestingly, our results indicate that the relative enrichment of lipid rafts in these signalling proteins may not be a consequence of protein translocation to these domains upon platelet stimulation, but the result of a massive loss in cytoskeletal proteins after platelet activation. Thus, this study may help to better understand the effects of platelet activation in the reorganization of lipid rafts and set the basis for further proteomic studies of these membrane microdomains in platelets. SIGNIFICANCE: We performed the first proteomic comparative analysis of lipid rafts- protein composition in platelets activated through GPVI and CLEC-2 receptors and in resting state. We identified a number of signalling proteins essential for platelet activation relatively enriched in platelets activated through both receptors, and we show that lipid rafts reorganization upon platelet activation leads to a loss in cytoskeletal proteins, highly associated to these domains in resting platelets.
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Affiliation(s)
- Irene Izquierdo
- Platelet Proteomics Group, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Universidad de Santiago de Compostela, Instituto de Investigación Sanitaria (IDIS), Santiago de Compostela, Spain
| | - María N Barrachina
- Platelet Proteomics Group, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Universidad de Santiago de Compostela, Instituto de Investigación Sanitaria (IDIS), Santiago de Compostela, Spain
| | - Lidia Hermida-Nogueira
- Platelet Proteomics Group, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Universidad de Santiago de Compostela, Instituto de Investigación Sanitaria (IDIS), Santiago de Compostela, Spain
| | - Vanessa Casas
- CSIC/UAB Proteomics Laboratory, IIBB-CSIC-IDIBAPS, Barcelona, Spain
| | - Johannes A Eble
- Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany
| | | | - Joaquín Abián
- CSIC/UAB Proteomics Laboratory, IIBB-CSIC-IDIBAPS, Barcelona, Spain
| | - Ángel García
- Platelet Proteomics Group, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Universidad de Santiago de Compostela, Instituto de Investigación Sanitaria (IDIS), Santiago de Compostela, Spain.
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7
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Rigg RA, McCarty OJT, Aslan JE. Heat Shock Protein 70 (Hsp70) in the Regulation of Platelet Function. REGULATION OF HEAT SHOCK PROTEIN RESPONSES 2018. [DOI: 10.1007/978-3-319-74715-6_14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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8
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Haining EJ, Matthews AL, Noy PJ, Romanska HM, Harris HJ, Pike J, Morowski M, Gavin RL, Yang J, Milhiet PE, Berditchevski F, Nieswandt B, Poulter NS, Watson SP, Tomlinson MG. Tetraspanin Tspan9 regulates platelet collagen receptor GPVI lateral diffusion and activation. Platelets 2017; 28:629-642. [PMID: 28032533 PMCID: PMC5706974 DOI: 10.1080/09537104.2016.1254175] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 10/06/2016] [Accepted: 10/20/2016] [Indexed: 12/14/2022]
Abstract
The tetraspanins are a superfamily of four-transmembrane proteins, which regulate the trafficking, lateral diffusion and clustering of the transmembrane proteins with which they interact. We have previously shown that tetraspanin Tspan9 is expressed on platelets. Here we have characterised gene-trap mice lacking Tspan9. The mice were viable with normal platelet numbers and size. Tspan9-deficient platelets were specifically defective in aggregation and secretion induced by the platelet collagen receptor GPVI, despite normal surface GPVI expression levels. A GPVI activation defect was suggested by partially impaired GPVI-induced protein tyrosine phosphorylation. In mechanistic experiments, Tspan9 and GPVI co-immunoprecipitated and co-localised, but super-resolution imaging revealed no defects in collagen-induced GPVI clustering on Tspan9-deficient platelets. However, single particle tracking using total internal reflection fluorescence microscopy showed that GPVI lateral diffusion was reduced by approximately 50% in the absence of Tspan9. Therefore, Tspan9 plays a fine-tuning role in platelet activation by regulating GPVI membrane dynamics.
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Affiliation(s)
- Elizabeth J. Haining
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Alexandra L. Matthews
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Peter J. Noy
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | | | - Helen J. Harris
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Jeremy Pike
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
- PSIBS Doctoral Training Centre, School of Chemistry, University of Birmingham, Birmingham, UK
| | - Martina Morowski
- Department of Experimental Biomedicine, University Hospital, University of Würzburg, Würzburg, Germany
| | - Rebecca L. Gavin
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Jing Yang
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Pierre-Emmanuel Milhiet
- INSERM U1054, CNRS, UMR 5048, Centre de Biochimie Structurale, Montpellier University, France
| | - Fedor Berditchevski
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Bernhard Nieswandt
- Department of Experimental Biomedicine, University Hospital, University of Würzburg, Würzburg, Germany
| | - Natalie S. Poulter
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Steve P. Watson
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Michael G. Tomlinson
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
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9
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Kwon HW, Lee DH. The Inhibitory Effects of Cordycepin on Phosphoproteins including PI3K, Akt, and p38. KOREAN JOURNAL OF CLINICAL LABORATORY SCIENCE 2017. [DOI: 10.15324/kjcls.2017.49.2.99] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- Hyuk-Woo Kwon
- College of Veterinary Medicine, Kyungpook National University, Daegu, Korea
| | - Dong-Ha Lee
- Department of Biomedical Laboratory Science, Korea Nazarene University, Cheonan, Korea
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10
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Bye AP, Unsworth AJ, Gibbins JM. Platelet signaling: a complex interplay between inhibitory and activatory networks. J Thromb Haemost 2016; 14:918-30. [PMID: 26929147 PMCID: PMC4879507 DOI: 10.1111/jth.13302] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 02/11/2016] [Indexed: 01/22/2023]
Abstract
The role of platelets in hemostasis and thrombosis is dependent on a complex balance of activatory and inhibitory signaling pathways. Inhibitory signals released from the healthy vasculature suppress platelet activation in the absence of platelet receptor agonists. Activatory signals present at a site of injury initiate platelet activation and thrombus formation; subsequently, endogenous negative signaling regulators dampen activatory signals to control thrombus growth. Understanding the complex interplay between activatory and inhibitory signaling networks is an emerging challenge in the study of platelet biology, and necessitates a systematic approach to utilize experimental data effectively. In this review, we will explore the key points of platelet regulation and signaling that maintain platelets in a resting state, mediate activation to elicit thrombus formation, or provide negative feedback. Platelet signaling will be described in terms of key signaling molecules that are common to the pathways activated by platelet agonists and can be described as regulatory nodes for both positive and negative regulators.
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Affiliation(s)
- A P Bye
- Institute of Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | - A J Unsworth
- Institute of Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | - J M Gibbins
- Institute of Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
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Belleville-Rolland T, Sassi Y, Decouture B, Dreano E, Hulot JS, Gaussem P, Bachelot-Loza C. MRP4 (ABCC4) as a potential pharmacologic target for cardiovascular disease. Pharmacol Res 2016; 107:381-389. [PMID: 27063943 DOI: 10.1016/j.phrs.2016.04.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 04/02/2016] [Indexed: 01/13/2023]
Abstract
This review focuses on multidrug resistance protein 4 (MRP4 or ABCC4) that has recently been shown to play a role in cAMP homeostasis, a key-pathway in vascular biology and in platelet functions. In vascular system, recent data provide evidence that inhibition of MRP4 prevents human coronary artery smooth muscle cell proliferation in vitro and in vivo, as well as human pulmonary artery smooth muscle cell proliferation in vitro and pulmonary hypertension in mice in vivo. In the heart, MRP4 silencing in adult rat ventricular myocytes results in an increase in intracellular cAMP levels leading to enhanced cardiomyocyte contractility. However, a prolonged inhibition of MRP4 can promote cardiac hypertrophy. In addition, secreted cAMP, through its metabolite adenosine, prevents adrenergically induced cardiac hypertrophy and fibrosis. Finally, MRP4 inhibition in platelets induces a moderate thrombopathy. The localization of MRP4 underlines the emerging concept of cAMP compartmentalization in platelets, which is a major regulatory mechanism in other cells. cAMP storage in platelet dense granules might limit the cAMP cytosolic concentration upon adenylate cyclase activation, a necessary step to induce platelet activation. In this review, we discuss the therapeutic potential of direct pharmacological inhibition of MRP4 in atherothrombotic disease, via its vasodilating and antiplatelet effects.
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Affiliation(s)
- Tiphaine Belleville-Rolland
- Inserm UMR-S1140, Faculté de Pharmacie, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France; AP-HP, Hôpital Européen Georges Pompidou, Service dhématologie biologique, Paris, France
| | - Yassine Sassi
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Benoit Decouture
- Inserm UMR-S1140, Faculté de Pharmacie, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Elise Dreano
- Inserm UMR-S1140, Faculté de Pharmacie, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Jean-Sébastien Hulot
- AP-HP, Institute of Cardiometabolism and Nutrition (ICAN), Pitié-Salpêtrière Hospital, F-75013 Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, France
| | - Pascale Gaussem
- Inserm UMR-S1140, Faculté de Pharmacie, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France; AP-HP, Hôpital Européen Georges Pompidou, Service dhématologie biologique, Paris, France
| | - Christilla Bachelot-Loza
- Inserm UMR-S1140, Faculté de Pharmacie, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
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12
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Rigg RA, Healy LD, Nowak MS, Mallet J, Thierheimer MLD, Pang J, McCarty OJT, Aslan JE. Heat shock protein 70 regulates platelet integrin activation, granule secretion and aggregation. Am J Physiol Cell Physiol 2016; 310:C568-75. [PMID: 26764050 DOI: 10.1152/ajpcell.00362.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 01/10/2016] [Indexed: 12/26/2022]
Abstract
Molecular chaperones that support protein quality control, including heat shock protein 70 (Hsp70), participate in diverse aspects of cellular and physiological function. Recent studies have reported roles for specific chaperone activities in blood platelets in maintaining hemostasis; however, the functions of Hsp70 in platelet physiology remain uninvestigated. Here we characterize roles for Hsp70 activity in platelet activation and function. In vitro biochemical, microscopy, flow cytometry, and aggregometry assays of platelet function, as well as ex vivo analyses of platelet aggregate formation in whole blood under shear, were carried out under Hsp70-inhibited conditions. Inhibition of platelet Hsp70 blocked platelet aggregation and granule secretion in response to collagen-related peptide (CRP), which engages the immunoreceptor tyrosine-based activation motif-bearing collagen receptor glycoprotein VI (GPVI)-Fc receptor-γ chain complex. Hsp70 inhibition also reduced platelet integrin-αIIbβ3 activation downstream of GPVI, as Hsp70-inhibited platelets showed reduced PAC-1 and fibrinogen binding. Ex vivo, pharmacological inhibition of Hsp70 in human whole blood prevented the formation of platelet aggregates on collagen under shear. Biochemical studies supported a role for Hsp70 in maintaining the assembly of the linker for activation of T cells signalosome, which couples GPVI-initiated signaling to integrin activation, secretion, and platelet function. Together, our results suggest that Hsp70 regulates platelet activation and function by supporting linker for activation of T cells-associated signaling events downstream of platelet GPVI engagement, suggesting a role for Hsp70 in the intracellular organization of signaling systems that mediate platelet secretion, "inside-out" activation of platelet integrin-αIIbβ3, platelet-platelet aggregation, and, ultimately, hemostatic plug and thrombus formation.
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Affiliation(s)
- Rachel A Rigg
- Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Laura D Healy
- Department of Cell, Developmental & Cancer Biology, School of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Marie S Nowak
- Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, Oregon; Department of Medical Physics, Universite des Sciences et Technologies de Lille, Villeneuve d'Ascq, France; and
| | - Jérémy Mallet
- Department of Medical Physics, Universite des Sciences et Technologies de Lille, Villeneuve d'Ascq, France; and
| | - Marisa L D Thierheimer
- Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, Oregon; School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, Oregon
| | - Jiaqing Pang
- Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Owen J T McCarty
- Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, Oregon; Department of Cell, Developmental & Cancer Biology, School of Medicine, Oregon Health & Science University, Portland, Oregon; Division of Hematology and Medical Oncology, School of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Joseph E Aslan
- Knight Cardiovascular Institute, School of Medicine, Oregon Health & Science University, Portland, Oregon;
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13
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Gaul V, Lopez SG, Lentz BR, Moran N, Forster RJ, Keyes TE. The lateral diffusion and fibrinogen induced clustering of platelet integrin αIIbβ3 reconstituted into physiologically mimetic GUVs. Integr Biol (Camb) 2015; 7:402-11. [PMID: 25720532 DOI: 10.1039/c5ib00003c] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Platelet integrin αIIbβ3 is a key mediator of platelet activation and thrombosis. Upon activation αIIbβ3 undergoes significant conformational rearrangement, inducing complex bidirectional signalling and protein recruitment leading to platelet activation. Reconstituted lipid models of the integrin can enhance our understanding of the structural and mechanistic details of αIIbβ3 behaviour away from the complexity of the platelet machinery. Here, a novel method of αIIbβ3 insertion into Giant Unilamellar Vesicles (GUVs) is described that allows for effective integrin reconstitution unrestricted by lipid composition. αIIbβ3 was inserted into two GUV lipid compositions that seek to better mimic the platelet membrane. First, "nature's own", comprising 32% DOPC, 25% DOPE, 20% CH, 15% SM and 8% DOPS, intended to mimic the platelet cell membrane. Fluorescence Lifetime Correlation Spectroscopy (FLCS) reveals that exposure of the integrin to the activators Mn(2+) or DTT does not influence the diffusion coefficient of αIIbβ3. Similarly, exposure to αIIbβ3's primary ligand fibrinogen (Fg) alone does not affect αIIbβ3's diffusion coefficient. However, addition of Fg with either activator reduces the integrin diffusion coefficient from 2.52 ± 0.29 to μm(2) s(-1) to 1.56 ± 0.26 (Mn(2+)) or 1.49 ± 0.41 μm(2) s(-1) (DTT) which is consistent with aggregation of activated αIIbβ3 induced by fibrinogen binding. The Multichannel Scaler (MCS) trace shows that the integrin-Fg complex diffuses through the confocal volume in clusters. Using the Saffman-Delbrück model as a first approximation, the diffusion coefficient of the complex suggests at least a 20-fold increase in the radius of membrane bound protein, consistent with integrin clustering. Second, αIIbβ3 was also reconstituted into a "raft forming" GUV with well defined liquid disordered (Ld) and liquid ordered (Lo) phases. Using confocal microscopy and lipid partitioning dyes, αIIbβ3 showed an affinity for the DOPC rich Ld phase of the raft forming GUVs, and was effectively excluded from the cholesterol and sphingomyelin rich Lo phase. Activation and Fg binding of the integrin did not alter the distribution of αIIbβ3 between the lipid phases. This observation suggests partitioning of the activated fibrinogen bound αIIbβ3 into cholesterol rich domains is not responsible for the integrin clustering observed.
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Affiliation(s)
- Vinnie Gaul
- School of Chemical Sciences and National Biophotonics and Imaging Platform, Dublin City University, Dublin 9, Ireland.
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The ABCC4 membrane transporter modulates platelet aggregation. Blood 2015; 126:2307-19. [PMID: 26405223 DOI: 10.1182/blood-2014-08-595942] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 09/17/2015] [Indexed: 01/13/2023] Open
Abstract
Controlling the activation of platelets is a key strategy to mitigate cardiovascular disease. Previous studies have suggested that the ATP-binding cassette (ABC) transporter, ABCC4, functions in platelet-dense granules. Using plasma membrane biotinylation and super-resolution microscopy, we demonstrate that ABCC4 is primarily expressed on the plasma membrane of both mouse and human platelets. Platelets lacking ABCC4 have unchanged dense-granule function, number, and volume, but harbor a selective impairment in collagen-induced aggregation. Accordingly, Abcc4 knockout (KO) platelet attachment to a collagen substratum was also faulty and associated with elevated intracellular cyclic AMP (cAMP) and reduced plasma membrane localization of the major collagen receptor, GPVI. In the ferric-chloride vasculature injury model, Abcc4 KO mice exhibited markedly impaired thrombus formation. The attenuation of platelet aggregation by the phosphodiesterase inhibitor EHNA (a non-ABCC4 substrate), when combined with Abcc4 deficiency, illustrated a crucial functional interaction between phosphodiesterases and ABCC4. This was extended in vivo where EHNA dramatically prolonged the bleeding time, but only in Abcc4 KO mice. Further, we demonstrated in human platelets that ABCC4 inhibition, when coupled with phosphodiesterase inhibition, strongly impaired platelet aggregation. These findings have important clinical implications because they directly highlight an important relationship between ABCC4 transporter function and phosphodiesterases in accounting for the cAMP-directed activity of antithrombotic agents.
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Lee DH, Kim HH, Cho HJ, Yu YB, Kang HC, Kim JL, Lee JJ, Park HJ. Cordycepin-Enriched WIB801C from Cordyceps militaris Inhibits Collagen-Induced [Ca(2+)]i Mobilization via cAMP-Dependent Phosphorylation of Inositol 1, 4, 5-Trisphosphate Receptor in Human Platelets. Biomol Ther (Seoul) 2014; 22:223-31. [PMID: 25009703 PMCID: PMC4060073 DOI: 10.4062/biomolther.2014.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/02/2014] [Accepted: 05/12/2014] [Indexed: 02/02/2023] Open
Abstract
In this study, we prepared cordycepin-enriched (CE)-WIB801C, a n-butanol extract of Cordyceps militaris-hypha, and investigated the effect of CE-WIB801C on collagen-induced human platelet aggregation. CE-WIB801C dose-dependently inhibited collagen-induced platelet aggregation, and its IC50 value was 175 μg/ml. CE-WIB801C increased cAMP level more than cGMP level, but inhibited collagen-elevated [Ca2+]i mobilization and thromboxane A2 (TXA2) production. cAMP-dependent protein kinase (A-kinase) inhibitor Rp-8-Br-cAMPS increased the CE-WIB801C-downregulated [Ca2+]i level in a dose dependent manner, and strongly inhibited CE-WIB801C-induced inositol 1, 4, 5-trisphosphate receptor (IP3R) phosphorylation. These results suggest that the inhibition of [Ca2+]i mobilization by CE-WIB801C is resulted from the cAMP/A-kinase-dependent phosphorylation of IP3R. CE-WIB801C suppressed TXA2 production, but did not inhibit the activities of cyclooxygenase-1 (COX-1) and TXA2 synthase (TXAS). These results suggest that the inhibition of TXA2 production by WIB801C is not resulted from the direct inhibition of COX-1 and TXAS. In this study, we demonstrate that CE-WIB801C with cAMP-dependent Ca2+-antagonistic antiplatelet effects may have preventive or therapeutic potential for platelet aggregation-mediated diseases, such as thrombosis, myocardial infarction, atherosclerosis, and ischemic cerebrovascular disease.
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Affiliation(s)
- Dong-Ha Lee
- Department of Biomedical Laboratory Science, College of Biomedical Science and Engineering, Inje University, Gimhae 621-749
| | - Hyun-Hong Kim
- Department of Biomedical Laboratory Science, College of Biomedical Science and Engineering, Inje University, Gimhae 621-749
| | - Hyun-Jeong Cho
- Department of Biomedical Laboratory Science, College of Medical Science, Konyang University, Daejeon 302-718
| | - Young-Bin Yu
- Department of Biomedical Laboratory Science, College of Medical Science, Konyang University, Daejeon 302-718
| | - Hyo-Chan Kang
- Department of Medical Laboratory Science, Dong-Eui Institute of Technology, Busan 614-715
| | - Jong-Lae Kim
- Bioscience & Biotechnology Team, Central Research Center, Whanin Pharm. Co., Ltd., Suwon 443-766, Republic of Korea
| | - Jong-Jin Lee
- Bioscience & Biotechnology Team, Central Research Center, Whanin Pharm. Co., Ltd., Suwon 443-766, Republic of Korea
| | - Hwa-Jin Park
- Department of Biomedical Laboratory Science, College of Biomedical Science and Engineering, Inje University, Gimhae 621-749
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Boulaftali Y, Hess PR, Kahn ML, Bergmeier W. Platelet immunoreceptor tyrosine-based activation motif (ITAM) signaling and vascular integrity. Circ Res 2014; 114:1174-84. [PMID: 24677237 PMCID: PMC4000726 DOI: 10.1161/circresaha.114.301611] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 02/18/2014] [Indexed: 01/27/2023]
Abstract
Platelets are well-known for their critical role in hemostasis, that is, the prevention of blood loss at sites of mechanical vessel injury. Inappropriate platelet activation and adhesion, however, can lead to thrombotic complications, such as myocardial infarction and stroke. To fulfill its role in hemostasis, the platelet is equipped with various G protein-coupled receptors that mediate the response to soluble agonists such as thrombin, ADP, and thromboxane A2. In addition to G protein-coupled receptors, platelets express 3 glycoproteins that belong to the family of immunoreceptor tyrosine-based activation motif receptors: Fc receptor γ chain, which is noncovalently associated with the glycoprotein VI collagen receptor, C-type lectin 2, the receptor for podoplanin, and Fc receptor γII A, a low-affinity receptor for immune complexes. Although both genetic and chemical approaches have documented a critical role for platelet G protein-coupled receptors in hemostasis, the contribution of immunoreceptor tyrosine-based activation motif receptors to this process is less defined. Studies performed during the past decade, however, have identified new roles for platelet immunoreceptor tyrosine-based activation motif signaling in vascular integrity in utero and at sites of inflammation. The purpose of this review is to summarize recent findings on how platelet immunoreceptor tyrosine-based activation motif signaling controls vascular integrity, both in the presence and absence of mechanical injury.
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Affiliation(s)
- Yacine Boulaftali
- From the McAllister Heart Institute (Y.B., W.B.) and Department of Biochemistry and Biophysics (W.B.), University of North Carolina, Chapel Hill; and Department of Medicine and Division of Cardiology, University of Pennsylvania, Philadelphia (P.R.H., M.L.K.)
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17
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O'Donnell VB, Murphy RC, Watson SP. Platelet lipidomics: modern day perspective on lipid discovery and characterization in platelets. Circ Res 2014; 114:1185-203. [PMID: 24677238 PMCID: PMC4021279 DOI: 10.1161/circresaha.114.301597] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Lipids are diverse families of biomolecules that perform essential structural and signaling roles in platelets. Their formation and metabolism are tightly controlled by enzymes and signal transduction pathways, and their dysregulation leads to significant defects in platelet function and disease. Platelet activation is associated with significant changes to membrane lipids, and formation of diverse bioactive lipids plays essential roles in hemostasis. In recent years, new generation mass spectrometry analysis of lipids (termed lipidomics) has begun to alter our understanding of how these molecules participate in key cellular processes. Although the application of lipidomics to platelet biology is still in its infancy, seminal earlier studies have shaped our knowledge of how lipids regulate key aspects of platelet biology, including aggregation, shape change, coagulation, and degranulation, as well as how lipids generated by platelets influence other cells, such as leukocytes and the vascular wall, and thus how they regulate hemostasis, vascular integrity, and inflammation, as well as contribute to pathologies, including arterial/deep vein thrombosis and atherosclerosis. This review will provide a brief historical perspective on the characterization of lipids in platelets, then an overview of the new generation lipidomic approaches, their recent application to platelet biology, and future perspectives for research in this area. The major platelet-regulatory lipid families, their formation, metabolism, and their role in health and disease, will be summarized.
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Affiliation(s)
- Valerie B O'Donnell
- From the Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (V.B.O'D.); Department of Pharmacology, University of Colorado at Denver, Aurora (R.C.M.); and Birmingham Platelet Group, Centre for Cardiovascular Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, Birmingham, United Kingdom (S.P.W.)
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Fälker K, Klarström-Engström K, Bengtsson T, Lindahl TL, Grenegård M. The Toll-like receptor 2/1 (TLR2/1) complex initiates human platelet activation via the src/Syk/LAT/PLCγ2 signalling cascade. Cell Signal 2014; 26:279-86. [DOI: 10.1016/j.cellsig.2013.11.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 11/06/2013] [Indexed: 11/16/2022]
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19
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Lee DH, Kim HH, Cho HJ, Bae JS, Yu YB, Park HJ. Antiplatelet effects of caffeic acid due to Ca(2+) mobilizationinhibition via cAMP-dependent inositol-1, 4, 5-trisphosphate receptor phosphorylation. J Atheroscler Thromb 2013; 21:23-37. [PMID: 24088646 DOI: 10.5551/jat.18994] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
AIM In this study, we investigated the effects of caffeic acid (CAFA), a phenolic acid, on Ca(2+)-antagonistic cyclic nucleotides associated with the phosphorylation of inositol 1,4,5-trisphosphate receptor (IP3R) and vasodilator-stimulated phosphoprotein (VASP) and the thromboxane A2 (TXA2)-associated microsomal cyclooxygenase-1 (COX-1) activity in collagen (10 μg/mL)-stimulated platelet aggregation. METHODS Washed platelets (10(8)/mL) obtained from Sprague-Dawley rats (6-7 weeks old, male) were preincubated for 3 minutes at 37℃ in the presence of 2 mM exogenous CaCl2 with or without CAFA or other materials, stimulated with collagen (10 μg/mL) for 5 minutes, then used to determine the levels of intracellular cytosolic Ca(2+) ([Ca(2+)]i), TXA2, cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), COX-1 activity, VASP and IP3R phosphorylation. RESULTS CAFA dose-dependently inhibited collagen-induced platelet aggregation and suppressed the production of TXA2, an aggregation-inducing autacoid associated with the strong inhibition of COX-1 in platelet microsomes exhibiting cytochrome C reductase activity. CAFA dose-dependently inhibited collagen-elevated [Ca(2+)]i mobilization, which was increased by a cAMP-dependent protein kinase (A-kinase) inhibitor, Rp-8-Br-cAMPS, but not a cGMP-dependent protein kinase (G-kinase) inhibitor, Rp-8-Br-cGMPS. In addition, CAFA significantly increased the formation of cAMP and cGMP, intracellular Ca(2+)-antagonists that function as aggregation-inhibiting molecules. CAFA increased IP3R (320 kDa) phosphorylation, indicating the inhibition of IP3-mediated Ca(2+) release from internal stores (i.e. the dense tubular system) via the IP3R on collagen-activated platelets. Furthermore, CAFA-induced IP3R phosphorylation was strongly inhibited by an A-kinase inhibitor, Rp-8-Br-cAMPS, but only mildly inhibited by a G-kinase inhibitor, Rp-8-Br-cGMPS. These results suggest that the inhibition of [Ca(2+)]i mobilization by CAFA is resulted from the cAMP/A-kinase-dependent phosphorylation of IP3R. CAFA elevated the phosphorylation of VASP-Ser(157), an A-kinase substrate, but not the phosphorylation of VASP-Ser(239), a G-kinase substrate. We demonstrate that CAFA increases cAMP and subsequently phosphorylates both IP3R and VASP-Ser(157) through A-kinase activation to inhibit [Ca(2+)]i mobilization and TXA2 production via the inhibition of the COX-1 activity. CONCLUSIONS These results strongly indicate that CAFA is a potent beneficial compound that elevates the level of cAMP-dependent protein phosphorylation in collagen-platelet interactions, which may result in the prevention of platelet aggregation-mediated thrombotic diseases.
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Affiliation(s)
- Dong-Ha Lee
- Department of Biomedical Laboratory Science, College of Biomedical Science and Engineering, Inje University
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20
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Ozaki Y, Suzuki-Inoue K, Inoue O. Platelet receptors activated via mulitmerization: glycoprotein VI, GPIb-IX-V, and CLEC-2. J Thromb Haemost 2013; 11 Suppl 1:330-9. [PMID: 23809136 DOI: 10.1111/jth.12235] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
While very different in structure, GPVI - the major collagen receptor on platelet membranes, the GPIb-IX-V complex - the receptor for von Willebrand factor, and CLEC-2, a novel platelet activation receptor for podoplanin, share several common features in terms of function and platelet activation signal transduction pathways. All employ Src family kinases (SFK), Syk, and other signaling molecules involving tyrosine phosphorylation, similar to those of immunoreceptors for T and B cells. There appear to be overlapping functional roles for these glycoproteins, and in some cases, they can compensate for each other, suggesting a degree of redundancy. New ligands for these receptors are being identified, which broadens their functional relevancy. This is particularly true for CLEC-2, whose functions beyond hemostasis are being explored. The common mode of signaling, clustering, and localization to glycosphingolipid-enriched microdomains (GEMs) suggest that GEMs are central to signaling function by ligand-dependent association of these receptors, SFK, Syk, phosphotyrosine phosphatases, and other signaling molecules.
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Affiliation(s)
- Y Ozaki
- Department of Laboratory Medicine, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan.
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21
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Séverin S, Nash CA, Mori J, Zhao Y, Abram C, Lowell CA, Senis YA, Watson SP. Distinct and overlapping functional roles of Src family kinases in mouse platelets. J Thromb Haemost 2012; 10:1631-45. [PMID: 22694307 PMCID: PMC4280098 DOI: 10.1111/j.1538-7836.2012.04814.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND OBJECTIVES Src family kinases (SFKs) play a critical role in initiating and propagating signals in platelets. The aims of this study were to quantitate SFK members present in platelets and to analyze their contribution to platelet regulation using glycoprotein VI (GPVI) and intregrin αIIbβ3, and in vivo. METHODS AND RESULTS Mouse platelets express four SFKs, Fgr, Fyn, Lyn and Src, with Lyn expressed at a considerably higher level than the others. Using mutant mouse models, we demonstrate that platelet activation by collagen-related peptide (CRP) is delayed and then potentiated in the absence of Lyn, but only marginally reduced in the absence of Fyn or Fgr, and unaltered in the absence of Src. Compound deletions of Lyn/Src or Fyn/Lyn, but not of Fyn/Src or Fgr/Lyn, exhibit a greater delay in activation relative to Lyn-deficient platelets. Fibrinogen-adherent platelets show reduced spreading in the absence of Src, potentiation in the absence of Lyn, but no change in the absence of Fyn or Fgr. In mice double-deficient in Lyn/Src or Fgr/Lyn, the inhibitory role of Lyn on spreading on fibrinogen is lost. Lyn is the major SFK-mediating platelet aggregation on collagen at arterial shear and its absence leads to a reduction in thrombus size in a laser injury model. CONCLUSION These results demonstrate that SFKs share individual and overlapping roles in regulating platelet activation, with Lyn having a dual role in regulating GPVI signaling and an inhibitory role downstream of αIIbβ3, which requires prior signaling through Src.
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Affiliation(s)
- S Séverin
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
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Deckmyn H, De Meyer SF, Broos K, Vanhoorelbeke K. Inhibitors of the interactions between collagen and its receptors on platelets. Handb Exp Pharmacol 2012:311-337. [PMID: 22918737 DOI: 10.1007/978-3-642-29423-5_13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
At sites of vascular injury, collagen-mediated platelet adhesion and activation have long been known as one of the first events in platelet-dependent thrombus formation. Studying patients with bleeding disorders that are caused by defective platelet adhesion to collagen resulted in the identification of several platelet collagen receptors, with glycoprotein VI and integrin α2β1 being the most important ones. Subsequent development of specific collagen receptor knockout mice and various inhibitors of platelet binding to collagen have further proven the role of these receptors in haemostasis and thrombosis. The search for clinically applicable inhibitors for use as antithrombotic drug has led to the identification of inhibitory antibodies, soluble receptor fragments, peptides, collagen-mimetics and proteins from snake venoms or haematophagous animals. In experimental settings, these inhibitors have a good antithrombotic effect, with little prolongation of bleeding times, suggesting a larger therapeutic window than currently available antiplatelet drugs. However, at present, none of the collagen receptor blockers are in clinical development yet.
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Affiliation(s)
- Hans Deckmyn
- Laboratory for Thrombosis Research, KU Leuven campus Kortrijk, Kortrijk, Belgium.
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23
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Suzuki-Inoue K, Inoue O, Ozaki Y. Novel platelet activation receptor CLEC-2: from discovery to prospects. J Thromb Haemost 2011; 9 Suppl 1:44-55. [PMID: 21781241 DOI: 10.1111/j.1538-7836.2011.04335.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
C-type lectin-like receptor 2 (CLEC-2) has been identified as a receptor for the platelet activating snake venom rhodocytin. CLEC-2 elicits powerful platelet activation signals in conjunction with Src, Syk kinases, and phospholipase Cγ2, similar to the collagen receptor glycoprotein (GP) VI/FcRγ-chain complex. In contrast to GPVI/FcRγ, which initiates platelet activation through the tandem YxxL motif immunoreceptor tyrosine-based activation motif (ITAM), CLEC-2 signals via the single YxxL motif hemi-ITAM. The endogenous ligand of CLEC-2 has been identified as podoplanin, which is expressed on the surface of tumour cells and facilitates tumour metastasis by inducing platelet activation. Studies of CLEC-2-deficient mice have revealed several physiological roles of CLEC-2. Podoplanin is also expressed in lymphatic endothelial cells as well as several other cells, including type I alveolar cells and kidney podocytes, but is absent from vascular endothelial cells. In the developmental stages, when the primary lymph sac is derived from the cardinal vein, podoplanin activates platelets in lymphatic endothelial cells by binding to CLEC-2, which facilitates blood/lymphatic vessel separation. Moreover, CLEC-2 is involved in thrombus stabilisation under flow conditions in part through homophilic interactions. However, the absence of CLEC-2 does not significantly increase bleeding tendency. CLEC-2 may be a good target protein for novel anti-platelet drugs or anti-metastatic drugs having therapeutic and preventive effects on arterial thrombosis and cancer, the primary causes of mortality in developed countries. In this article, we review the mechanisms of signal transduction, structure, expression, and function of CLEC-2.
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Affiliation(s)
- K Suzuki-Inoue
- Department of Clinical and Laboratory Medicine, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan
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Hořejší V, Otáhal P, Brdička T. LAT - an important raft-associated transmembrane adaptor protein. Delivered on 6 July 2009 at the 34th FEBS Congress in Prague, Czech Republic. FEBS J 2010; 277:4383-97. [DOI: 10.1111/j.1742-4658.2010.07831.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
SUMMARY The glycoprotein VI (GPVI)-FcR gamma-chain complex initiates powerful activation of platelets by the subendothelial matrix proteins collagen and laminin through an immunoreceptor tyrosine-based activation motif (ITAM)-regulated signaling pathway. ITAMs are characterized by two YxxL sequences separated by 6-12 amino acids and are found associated with several classes of immunoglobulin (Ig) and C-type lectin receptors in hematopoietic cells, including Fc receptors. Cross-linking of the Ig GPVI leads to phosphorylation of two conserved tyrosines in the FcR gamma-chain ITAM by Src family tyrosine kinases, followed by binding and activation of the tandem SH2 domain-containing Syk tyrosine kinase and stimulation of a downstream signaling cascade that culminates in activation of phospholipase Cgamma2 (PLCgamma2). In contrast, the C-type lectin receptor CLEC-2 mediates powerful platelet activation through Src and Syk kinases, but regulates Syk through a novel dimerization mechanism via a single YxxL motif known as a hemITAM. CLEC-2 is a receptor for podoplanin, which is expressed at high levels in several tissues, including type 1 lung alveolar cells, lymphatic endothelial cells, kidney podocytes and some tumors, but is absent from vascular endothelial cells and platelets. In this article, we compare the mechanism of platelet activation by GPVI and CLEC-2 and consider their functional roles in hemostasis and other vascular processes, including maintenance of vascular integrity, angiogenesis and lymphogenesis.
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Affiliation(s)
- S P Watson
- Centre for Cardiovascular Sciences, Institute for Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
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Phosphorylation of CLEC-2 is dependent on lipid rafts, actin polymerization, secondary mediators, and Rac. Blood 2010; 115:2938-46. [PMID: 20154214 DOI: 10.1182/blood-2009-12-257212] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The C-type lectin-like receptor 2 (CLEC-2) activates platelets through Src and Syk tyrosine kinases via a single cytoplasmic YxxL motif known as a hem immunoreceptor tyrosine-based activation motif (hemITAM). Here, we demonstrate using sucrose gradient ultracentrifugation and methyl-beta-cyclodextrin treatment that CLEC-2 translocates to lipid rafts upon ligand engagement and that translocation is essential for hemITAM phosphorylation and signal initiation. HemITAM phosphorylation, but not translocation, is also critically dependent on actin polymerization, Rac1 activation, and release of ADP and thromboxane A(2) (TxA(2)). The role of ADP and TxA(2) in mediating phosphorylation is dependent on ligand engagement and rac activation but is independent of platelet aggregation. In contrast, tyrosine phosphorylation of the GPVI-FcRgamma-chain ITAM, which has 2 YxxL motifs, is independent of actin polymerization and secondary mediators. These results reveal a unique series of proximal events in CLEC-2 phosphorylation involving actin polymerization, secondary mediators, and Rac activation.
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Abstract
Members of the Src family of protein tyrosine kinases play important roles in platelet adhesion, activation, and aggregation. The purpose of this review is to summarize current knowledge regarding how Src family kinase activity is regulated in general, to describe what is known about mechanisms underlying SFK activation in platelets, and to discuss platelet proteins that contribute to SFK inactivation, particularly those that use phosphotyrosine-containing sequences to recruit phosphatases and kinases to sites of SFK activity.
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Affiliation(s)
- D K Newman
- Blood Center of Wisconsin, Blood Research Institute, Milwaukee, WI 53226, USA.
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28
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Abstract
Integrins are the principal cell adhesion receptors that mediate leukocyte migration and activation in the immune system. These receptors signal bidirectionally through the plasma membrane in pathways referred to as inside-out and outside-in signaling. Each of these pathways is mediated by conformational changes in the integrin structure. Such changes allow high-affinity binding of the receptor with counter-adhesion molecules on the vascular endothelium or extracellular matrix and lead to association of the cytoplasmic tails of the integrins with intracellular signaling molecules. Leukocyte functional responses resulting from outside-in signaling include migration, proliferation, cytokine secretion, and degranulation. Here, we review the key signaling events that occur in the inside-out versus outside-in pathways, highlighting recent advances in our understanding of how integrins are activated by a variety of stimuli and how they mediate a diverse array of cellular responses.
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Affiliation(s)
- Clare L Abram
- Program in Immunology, Department of Laboratory Medicine, University of California, San Francisco, California 94143-0451, USA
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29
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Canobbio I, Trionfini P, Guidetti GF, Balduini C, Torti M. Targeting of the small GTPase Rap2b, but not Rap1b, to lipid rafts is promoted by palmitoylation at Cys176 and Cys177 and is required for efficient protein activation in human platelets. Cell Signal 2008; 20:1662-70. [DOI: 10.1016/j.cellsig.2008.05.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Accepted: 05/26/2008] [Indexed: 10/22/2022]
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30
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31
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Cho HJ, Rhee MH, Cho JY, Kim HS, Ok WJ, Kang HJ, Park HJ. Cordycepin (3'-deoxyadenosine) Has an Anti-platelet Effect by Regulating the cGMP-Associated Pathway of Human Platelet Activation. Prev Nutr Food Sci 2007. [DOI: 10.3746/jfn.2007.12.3.141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Abstract
Adapters are multidomain molecules that recruit effector proteins during signal transduction by immunoreceptors and integrins. The absence of these scaffolding molecules profoundly affects development and function of various hematopoietic lineages, underscoring their importance as regulators of signaling cascades. An emerging aspect of the mechanism by which engaged immunoreceptors and integrins transmit signals within the cell is by differential usage of various adapters that function to nucleate formation of distinct signaling complexes in a specific location within the cell. In this review, we discuss the mechanisms by which adapter proteins coordinate signal transduction with an emphasis on the role of subcellular compartmentalization in adapter function.
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Affiliation(s)
- Natalie Bezman
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
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Abstract
A common signaling pathway is known to operate downstream of immunoreceptors, such as the T-cell, B-cell, or Fc receptors, following engagement by their respective ligands. This pathway involves Src family kinase-mediated tyrosine phosphorylation of immunoreceptor tyrosine-based activation motifs (ITAMs) that recruit and activate spleen tyrosine kinase (Syk) or Zap70 (zeta-associated protein of 70 kDa) kinases, which in turn activate a variety of downstream signals. Evidence has been building from a variety of sources, particularly mouse models, that molecules involved in the immunoreceptor signaling pathway are also required for signals initiated by integrins. Integrins are the major cell surface receptors that mediate adhesion of leukocytes to a variety of extracellular matrix proteins and counter-receptors expressed on endothelial cells. Integrin ligation is a critical step in the activation of leukocyte effector functions (such as neutrophil degranulation or lymphocyte proliferation). Integrin signaling through pathways common to those utilized by immunoreceptors provides a mechanism by which leukocyte adhesion can regulate activation of cellular responses. In animal models, integrin-mediated signal transduction plays a critical role in inflammatory disease. In this review, we discuss the convergence of immunoreceptor and integrin signaling, focusing on how these pathways modulate leukocyte activation.
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Affiliation(s)
- Clare L Abram
- Department of Laboratory Medicine, University of California, San Francisco, CA 94143-0451, USA
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Farndale RW, Slatter DA, Siljander PRM, Jarvis GE. Platelet receptor recognition and cross-talk in collagen-induced activation of platelets. J Thromb Haemost 2007; 5 Suppl 1:220-9. [PMID: 17635730 DOI: 10.1111/j.1538-7836.2007.02521.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Comprehensive mapping of protein-binding sites within human collagen III has allowed the recognition motifs for integrin alpha(2)beta(1) and VWF A3 domain to be identified. Glycoprotein VI-binding sites are understood, although less well defined. This information, together with recent developments in understanding collagen fiber architecture, and crystal structures of the receptor collagen-binding domains, allows a coherent model for the interaction of collagen with the platelet surface to be developed. This complements our understanding of the orchestration of receptor presentation by membrane microdomains, such that the polyvalent collagen surface may stabilize signaling complexes within the heterogeneous receptor composition of the lipid raft. The ensuing interactions lead to the convergence of signals from each of the adhesive receptors, mediated by FcR gamma-chain and/or FcgammaRIIa, leading to concerted and co-operative platelet activation. Each receptor has a shear-dependent role, VWF/GpIb essential at high shear, and alpha(2)beta(1) at low and intermediate shear, whilst GpVI provides core signals that contribute to enhanced integrin affinity, tighter binding to collagen and consequent platelet activation.
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Affiliation(s)
- R W Farndale
- Department of Biochemistry, University of Cambridge, Cambridge, UK.
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35
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Jin W, Inoue O, Tamura N, Suzuki-Inoue K, Satoh K, Berndt MC, Handa M, Goto S, Ozaki Y. A role for glycosphingolipid-enriched microdomains in platelet glycoprotein Ib-mediated platelet activation. J Thromb Haemost 2007; 5:1034-40. [PMID: 17461932 DOI: 10.1111/j.1538-7836.2007.02476.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Glycoprotein (GP) Ib, a platelet von Willebrand factor (VWF) receptor, plays a crucial role in thrombosis and hemostasis. As recent reports have suggested that GPIb partially locates in a particular region, designated as glycosphingolipid-enriched microdomains (GEMs), we hypothesized that GEMs play a central role in GPIb-mediated platelet activation. METHODS Platelets were stimulated by VWF/botrocetin to activate platelets through GPIb. GEMs and non-GEMs were isolated by sucrose density gradient ultracentrifugation and the location of signaling molecules characterized. The role of GEMs-mediated signaling in platelet behavior was tested by platelet aggregation and by platelet interaction with immobilized VWF under flow conditions when GEMs were disrupted by methyl-beta-cyclodextrin (MbetaCD). RESULTS GPIb was partially translocated to GEMs upon VWF/botrocetin stimulation. Immunoprecipitation of GPIb in GEMs and non-GEMs revealed that the tyrosine kinases, Src and Lyn, were associated with GPIb only in GEMs after GPIb-stimulation, and not in non-GEMs. Activation of PLCgamma2 was more intense in GEMs than non-GEMs. Disruption of GEMs by MbetaCD strongly inhibited tyrosine phosphorylation of Syk and PLCgamma2. Functional studies revealed that stable adhesion of platelets to a VWF-coated surface under flow was impaired by GEM disruption by MbetaCD. CONCLUSION The combined results suggest that GEMs play an important role in GPIb-mediated platelet activation.
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Affiliation(s)
- W Jin
- Department of Laboratory and Clinical Medicine, University of Yamanashi, Yamanashi, Japan
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36
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Pearce AC, McCarty OJT, Calaminus SDJ, Vigorito E, Turner M, Watson SP. Vav family proteins are required for optimal regulation of PLCgamma2 by integrin alphaIIbbeta3. Biochem J 2007; 401:753-61. [PMID: 17054426 PMCID: PMC1770845 DOI: 10.1042/bj20061508] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Vav proteins belong to the family of guanine-nucleotide-exchange factors for the Rho/Rac family of small G-proteins. In addition, they serve as important adapter proteins for the activation of PLCgamma (phospholipase Cgamma) isoforms by ITAM (immunoreceptor tyrosine-based activation motif) receptors, including the platelet collagen receptor GPVI (glycoprotein VI). Vav proteins are also regulated downstream of integrins, including the major platelet integrin alphaIIbbeta3, which has recently been shown to regulate PLCgamma2. In the present study, we have investigated the role of Vav family proteins in filopodia and lamellipodia formation on fibrinogen using platelets deficient in Vav1 and Vav3. Wild-type mouse platelets undergo a limited degree of spreading on fibrinogen, characterized by the formation of numerous filopodia and limited lamellipodia structures. Platelets deficient in Vav1 and Vav3 exhibit reduced filopodia and lamellipodia formation during spreading on fibrinogen. This is accompanied by reduced alphaIIbbeta3-mediated PLCgamma2 tyrosine phosphorylation and reduced Ca(2+) mobilization. In contrast, the G-protein agonist thrombin stimulates full spreading of control and Vav1/3-deficient platelets. Consistent with this, stimulation of F-actin (filamentous actin) formation and Rac activation by thrombin is not altered in Vav-deficient cells. These results demonstrate that Vav1 and Vav3 are required for optimal spreading and regulation of PLCgamma2 by integrin alphaIIbbeta3, but that their requirement is by-passed upon G-protein receptor activation.
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Affiliation(s)
- Andrew C Pearce
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, Division of Medical Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
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38
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Reineri S, Bertoni A, Sanna E, Baldassarri S, Sarasso C, Zanfa M, Canobbio I, Torti M, Sinigaglia F. Membrane lipid rafts coordinate estrogen-dependent signaling in human platelets. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2007; 1773:273-8. [PMID: 17208317 DOI: 10.1016/j.bbamcr.2006.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Revised: 11/02/2006] [Accepted: 12/06/2006] [Indexed: 11/22/2022]
Abstract
The impact of estrogens on the viability of cardiovascular system and their ability to regulate platelet function is still an open and debated question. We have previously shown that estrogen is able to significantly potentiate the aggregation induced by low doses of thrombin and to initiate a rapid and reversible signaling pathway mediated by ERbeta-directed activation of the tyrosine kinases Src and Pyk2 at the level of the plasma membrane. Lipid rafts are critical, cholesterol-enriched membrane domains, which play a major role in blood platelet activation processes. In this work, we investigated the role of lipid rafts in 17beta-estradiol signaling in human platelets. We observed that membrane rafts were essential for both 17beta-estradiol-dependent potentiation of platelet aggregation induced by subthreshold concentrations of thrombin and 17beta-estradiol-induced phosphorylation of Src. 17beta-estradiol caused the reversible translocation of ERbeta to the raft fractions and promoted the rapid and transient recruitment to, and activation within the membrane raft domains of the tyrosine kinases Src and Pyk2. The raft integrity was essential with this respect, as these effects of 17beta-estradiol were completely inhibited by cholesterol depletion. This paper provides evidence for the first time that membrane lipid rafts coordinate estrogen signaling in human platelets.
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Affiliation(s)
- Stefania Reineri
- Department of Medical Sciences, University "A. Avogadro", Via Solaroli 17, 28100-Novara, Italy
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39
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Quinter PG, Dangelmaier CA, Quinton TM, Kunapuli SP, Daniel JL. Glycoprotein VI agonists have distinct dependences on the lipid raft environment. J Thromb Haemost 2007; 5:362-8. [PMID: 17096705 DOI: 10.1111/j.1538-7836.2007.02309.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND It has been reported that the association of glycoprotein VI (GPVI) with lipid rafts regulates GPVI signaling in platelets. OBJECTIVE Secreted adenosine 5'-diphosphate (ADP) potentiates GPVI-induced platelet aggregation at particular agonist concentrations. We have investigated whether the decrease in GPVI signaling, previously reported in platelets with disrupted rafts, is a result of the loss of agonist potentiation by ADP. METHODS We disrupted platelet lipid rafts with methyl-beta-cyclodextrin and measured signaling events downstream of GPVI activation. RESULTS Lipid raft disruption decreases aggregation induced by low concentrations of convulxin, but this decrease is almost eliminated in the presence of ADP antagonists. Signaling indicators, such as protein phosphorylation and calcium mobilization, were not affected by raft disruption in collagen or convulxin stimulated platelets. Interestingly, however, raft disruption directly reduced GPVI signaling induced by collagen-related peptide. CONCLUSIONS Lipid rafts do not directly contribute to signaling by the physiologic agonist collagen. The effects of disruption of lipid rafts in in vitro assays can be attributed to inhibition of ADP feedback that potentiates GPVI signaling.
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Affiliation(s)
- P G Quinter
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA
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40
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Cho HJ, Cho JY, Rhee MH, Park HJ. Cordycepin (3'-deoxyadenosine) inhibits human platelet aggregation in a cyclic AMP- and cyclic GMP-dependent manner. Eur J Pharmacol 2006; 558:43-51. [PMID: 17229422 DOI: 10.1016/j.ejphar.2006.11.073] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Revised: 11/27/2006] [Accepted: 11/29/2006] [Indexed: 10/23/2022]
Abstract
Cordycepin (3'-deoxyadenosine) is isolated from Cordyceps militaris, a species of the fungal genus Cordyceps. Cordycepin is an ingredient used in traditional Chinese medicine and is prescribed for various diseases, such as cancer and chronic inflammation. In this study, we investigated the novel effect of cordycepin (3'-deoxyadenosine) on collagen-induced human platelet aggregation. Cordycepin inhibited dose-dependently collagen-induced platelet aggregation in the presence of various concentrations of exogenous CaCl(2). Of two aggregation-inducing molecules, cytosolic free Ca(2+) ([Ca(2+)](i)) and thromboxane A(2) (TXA(2)), cordycepin (500 microM) blocked the up-regulation of [Ca(2+)](i), by up to 74%, but suppressed TXA(2) production by 46%. Subsequently, Ca(2+)-dependent phosphorylation of both 47-kDa and 20-kDa proteins in collagen-treated platelets was potently diminished by cordycepin. However, upstream pathways for producing these two inducers, such as the activation of phospholipase C-gamma2 (PLC-gamma2) (assessed by the phosphotyrosine level) and the formation of inositol 1,4,5-trisphosphate (IP(3)), were not altered by cordycepin. Cordycepin increased the level of second messengers adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP) in collagen-stimulated platelets. Whereas the NO-sensitive guanylyl cyclase inhibitor ODQ did not alter the cordycepin-induced up-regulation of cGMP, the adenylyl cyclase inhibitor SQ22536 completely blocked the cAMP enhancement mediated by cordycepin, indicating that cordycepin had different modes of action. Therefore, our data suggest that the inhibitory effect of cordycepin on platelet aggregation might be associated with the down-regulation of [Ca(2+)](i) and the elevation of cAMP/cGMP production.
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Affiliation(s)
- Hyun-Jeong Cho
- Department of Biomedical Laboratory Science, College of Biomedical Science and Engineering, and Regional Research Center, Inje University, 607, Obang-Dong, Gimhae, Gyungnam, Republic of Korea
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41
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Beach D, Gonen R, Bogin Y, Reischl IG, Yablonski D. Dual role of SLP-76 in mediating T cell receptor-induced activation of phospholipase C-gamma1. J Biol Chem 2006; 282:2937-46. [PMID: 17148460 DOI: 10.1074/jbc.m606697200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Phospholipase C-gamma1 (PLC-gamma1) activation depends on a heterotrimeric complex of adaptor proteins composed of LAT, Gads, and SLP-76. Upon T cell receptor stimulation, a portion of PLC-gamma1 is recruited to a detergent-resistant membrane fraction known as the glycosphingolipid-enriched membrane microdomains (GEMs), or lipid rafts, to which LAT is constitutively localized. In addition to LAT, PLC-gamma1 GEM recruitment depended on SLP-76, and, in particular, required the Gads-binding domain of SLP-76. The N-terminal tyrosine phosphorylation sites and P-I region of SLP-76 were not required for PLC-gamma1 GEM recruitment, but were required for PLC-gamma1 phosphorylation at Tyr(783). Thus, GEM recruitment can be insufficient for full activation of PLC-gamma1 in the absence of a second SLP-76-mediated event. Indeed, a GEM-targeted derivative of PLC-gamma1 depended on SLP-76 for T cell receptor-induced phosphorylation at Tyr783 and subsequent NFAT activation. On a biochemical level, SLP-76 inducibly associated with both Vav and catalytically active ITK, which efficiently phosphorylated a PLC-gamma1 fragment at Tyr783 in vitro. Both associations were disrupted upon mutation of the N-terminal tyrosine phosphorylation sites of SLP-76. The P-I region deletion disrupted Vav association and reduced SLP-76-associated kinase activity. A smaller deletion within the P-I region, which does not impair PLC-gamma1 activation, did not impair the association with Vav, but reduced SLP-76-associated kinase activity. These results provide new insight into the multiple roles of SLP-76 and the functional importance of its interactions with other signaling proteins.
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Affiliation(s)
- Dvora Beach
- Rappaport Family Institute for Research in the Medical Sciences, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
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42
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Abstract
The immunoreceptor signaling pathway has classically been defined by its role in mediating intracellular signals downstream of immune receptors on circulating cells, but recent studies have revealed new and unexpected roles for this pathway in vascular biology. In platelets the immunoreceptor signaling pathway is coupled to 2 structurally distinct platelet collagen receptors, glycoprotein VI and integrin α2β1, and is required for the activation of platelets after exposure to vessel wall collagen during plaque rupture. During vascular development immunoreceptor signaling is required for proper formation of the lymphatic system, a role that has revealed the contribution of hematopoietic endothelial progenitors to that process. In conjunction with the identification of new biological roles in vascular cell types, new molecular mechanisms of activating this signaling pathway have been discovered, including activation by integrins and immunoreceptor tyrosine activation motifs (ITAMs) on receptors that do not function as part of the immune response. Here we discuss some of these recent findings and their implications for vascular biology and the treatment of human vascular diseases.
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Affiliation(s)
- Frederick F Samaha
- Department of Medicine and Division of Cardiology, University of Pennsylvania, Philadelphia, PA 19104, USA.
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43
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Lee FA, van Lier M, Relou IAM, Foley L, Akkerman JWN, Heijnen HFG, Farndale RW. Lipid rafts facilitate the interaction of PECAM-1 with the glycoprotein VI-FcR gamma-chain complex in human platelets. J Biol Chem 2006; 281:39330-8. [PMID: 17068334 DOI: 10.1074/jbc.m607930200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glycoprotein (GP) VI, the main signaling receptor for collagen on platelets, is expressed in complex with the FcR gamma-chain. The latter contains an immunoreceptor tyrosine-based activation motif, which becomes phosphorylated, initiating a signaling cascade leading to the rapid activation and aggregation of platelets. Previous studies have shown that signaling by immunoreceptor tyrosine-based activation motif-containing receptors is counteracted by signals from receptors with immunoreceptor tyrosine-based inhibitory motifs. Here we show, by immunoprecipitation, that the GPVI-FcR gamma-chain complex associates with the immunoreceptor tyrosine-based inhibitory motif-containing receptor, PECAM-1. In platelets stimulated with collagen-related peptide (CRP-XL), tyrosine phosphorylation of PECAM-1 precedes that of the FcR gamma-chain, implying direct regulation of the former. The GPVI-FcR gamma-chain complex and PECAM-1 were present in both lipid raft and soluble fractions in human platelets; this distribution was unaltered by activation with CRP-XL. Their association occurred in lipid rafts and was lost after lipid raft depletion using methyl-beta-cyclodextrin. We propose that lipid raft clustering facilitates the interaction of PECAM-1 with the GPVI-FcR gamma-chain complex, leading to the down-regulation of the latter.
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Affiliation(s)
- Fiona A Lee
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
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44
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Macaulay IC, Carr P, Gusnanto A, Ouwehand WH, Fitzgerald D, Watkins NA. Platelet genomics and proteomics in human health and disease. J Clin Invest 2006; 115:3370-7. [PMID: 16322782 PMCID: PMC1297260 DOI: 10.1172/jci26885] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Proteomic and genomic technologies provide powerful tools for characterizing the multitude of events that occur in the anucleate platelet. These technologies are beginning to define the complete platelet transcriptome and proteome as well as the protein-protein interactions critical for platelet function. The integration of these results provides the opportunity to identify those proteins involved in discrete facets of platelet function. Here we summarize the findings of platelet proteome and transcriptome studies and their application to diseases of platelet function.
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Affiliation(s)
- Iain C Macaulay
- Department of Haematology, University of Cambridge, Cambridge, UK
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45
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van Lier M, Lee F, Farndale RW, Gorter G, Verhoef S, Ohno-Iwashita Y, Akkerman JWN, Heijnen HFG. Adhesive surface determines raft composition in platelets adhered under flow. J Thromb Haemost 2005; 3:2514-25. [PMID: 16241950 DOI: 10.1111/j.1538-7836.2005.01597.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Adhesion to von Willebrand factor (VWF) induces platelet spreading, whereas adhesion to collagen induces aggregation. Here we report that cholesterol-rich domains (CRDs) or rafts play a critical role in clustering of receptors that control these responses. Platelets adhered to VWF and collagen show CRDs concentrated in filopodia which contain both the VWF receptor glycoprotein (GP) Ibalpha and the collagen receptor GPVI. Biochemical analysis of CRDs shows a threefold enrichment of GPIbalpha (but not GPVI) in VWF-adhered platelets and a fourfold enrichment of GPVI (but not GPIbalpha) in collagen-adhered platelets. Depletion of cholesterol (i) leaves the initial adhesion unchanged, (ii) inhibits spreading on VWF and aggregate formation on collagen, (iii) leaves filopodia formation intact, and (iv) reduces the localization in filopodia of GPIbalpha but not of GPVI. These data show that the adhesive substrate determines the composition of CRDs, and that cholesterol is crucial for redistribution of GPIbalpha but not of GPVI.
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Affiliation(s)
- M van Lier
- Laboratory for Thrombosis and Haemostasis, Department of Haematology, UMCU and Institute of Biomembranes, Utrecht, The Netherlands
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46
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García A, Watson SP, Dwek RA, Zitzmann N. Applying proteomics technology to platelet research. MASS SPECTROMETRY REVIEWS 2005; 24:918-930. [PMID: 15599945 DOI: 10.1002/mas.20047] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Platelets are small enucleated cells that circulate in the blood, where they play a key role in hemostasis and contribute to the formation of vascular plugs. Pathologically, they are involved in thrombosis and heart disease. Because platelets do not have a nucleus, proteomics offers a powerful way to approach their biology. Proteomics technology is based on the huge analytical power offered by mass spectrometry in combination with several separation techniques, such as two-dimensional gel electrophoresis (2DGE) or multidimensional liquid chromatography. Proteomics provides information about the complete set of proteins present in platelets, the platelet proteome, including post-translational variants. Over the last years, several research groups have applied proteomics to platelet research. A detailed analysis of the general proteome and signaling cascades in human platelets will improve our knowledge of platelet function, and thereby aid the development of new therapeutic agents to treat thrombotic diseases. This review presents the major advances in mass spectrometry-based proteomics techniques and their application to platelet research, and analyzes in detail the most relevant contributions to the field.
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Affiliation(s)
- Angel García
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, United Kingdom.
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47
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Inoue O, Suzuki-Inoue K, McCarty OJT, Moroi M, Ruggeri ZM, Kunicki TJ, Ozaki Y, Watson SP. Laminin stimulates spreading of platelets through integrin alpha6beta1-dependent activation of GPVI. Blood 2005; 107:1405-12. [PMID: 16219796 PMCID: PMC1895394 DOI: 10.1182/blood-2005-06-2406] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The extracellular matrix protein, laminin, supports platelet adhesion through binding to integrin alpha6beta1 In the present study, we demonstrate that human laminin, purified from placenta, also stimulates formation of filopodia and lamellipodia in human and mouse platelets through a pathway that is dependent on alpha6beta1 and the collagen receptor GPVI. The integrin alpha6beta1 is essential for adhesion to laminin, as demonstrated using an alpha6-blocking antibody, whereas GPVI is dispensable for this response, as shown using "knockout" mouse platelets. On the other hand, lamellipodia formation on laminin is completely inhibited in the absence of GPVI, although filopodia formation remains and is presumably mediated via alpha6beta1 Lamellipodia and filopodia formation are inhibited in Syk-deficient platelets, demonstrating a key role for the kinase in signaling downstream of GPVI and integrin alpha6beta1 GPVI was confirmed as a receptor for laminin using surface plasmon resonance spectroscopy and by demonstration of lamellipodia formation on laminin in the presence of collagenase. These results identify GPVI as a novel receptor for laminin and support a model in which integrin alpha6beta1 brings laminin to GPVI, which in turn mediates lamellipodia formation. We speculate that laminin contributes to platelet spreading in vivo through a direct interaction with GPVI.
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Affiliation(s)
- Osamu Inoue
- Department of Clinical and Laboratory Medicine, Yamanashi Medical University, 1110 Shimokato Tamaho Nakakoma, Yamanashi 409-3898, Japan.
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Maurice P, Waeckel L, Pires V, Sonnet P, Lemesle M, Arbeille B, Vassy J, Rochette J, Legrand C, Fauvel-Lafève F. The platelet receptor for type III collagen (TIIICBP) is present in platelet membrane lipid microdomains (rafts). Histochem Cell Biol 2005; 125:407-17. [PMID: 16205938 DOI: 10.1007/s00418-005-0076-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2005] [Indexed: 02/02/2023]
Abstract
Platelet interactions with collagen are orchestrated by the presence or the migration of platelet receptor(s) for collagen into lipid rafts, which are specialized lipid microdomains from the platelet plasma membrane enriched in signalling proteins. Electron microscopy shows that in resting platelets, TIIICBP, a receptor specific for type III collagen, is present on the platelet membrane and associated with the open canalicular system, and redistributes to the platelet membrane upon platelet activation. After platelet lysis by 1% Triton X-100 and the separation of lipid rafts on a discontinuous sucrose gradient, TIIICBP is recovered in lipid raft-containing fractions and Triton X-100 insoluble fractions enriched in cytoskeleton proteins. Platelet aggregation, induced by type III collagen, was inhibited after disruption of the lipid rafts by cholesterol depletion, whereas platelet adhesion under static conditions did not require lipid raft integrity. These results indicate that TIIICBP, a platelet receptor involved in platelet interaction with type III collagen, is localized within platelet lipid rafts where it could interact with other platelet receptors for collagen (GP VI and alpha2beta1 integrin) for efficient platelet activation.
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Affiliation(s)
- Pascal Maurice
- INSERM, U 553, IFR 105, Institut d'Hématologie, Université Paris VII Denis Diderot, 75475, Paris, France
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Arias-Salgado EG, Haj F, Dubois C, Moran B, Kasirer-Friede A, Furie BC, Furie B, Neel BG, Shattil SJ. PTP-1B is an essential positive regulator of platelet integrin signaling. ACTA ACUST UNITED AC 2005; 170:837-45. [PMID: 16115959 PMCID: PMC2171339 DOI: 10.1083/jcb.200503125] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Outside-in integrin αIIbβ3 signaling is required for normal platelet thrombus formation and is triggered by c-Src activation through an unknown mechanism. In this study, we demonstrate an essential role for protein–tyrosine phosphatase (PTP)–1B in this process. In resting platelets, c-Src forms a complex with αIIbβ3 and Csk, which phosphorylates c-Src tyrosine 529 to maintain c-Src autoinhibition. Fibrinogen binding to αIIbβ3 triggers PTP-1B recruitment to the αIIbβ3–c-Src–Csk complex in a manner that is dependent on c-Src and specific tyrosine (tyrosine 152 and 153) and proline (proline 309 and 310) residues in PTP-1B. Studies of PTP-1B–deficient mouse platelets indicate that PTP-1B is required for fibrinogen-dependent Csk dissociation from αIIbβ3, dephosphorylation of c-Src tyrosine 529, and c-Src activation. Furthermore, PTP-1B–deficient platelets are defective in outside-in αIIbβ3 signaling in vitro as manifested by poor spreading on fibrinogen and decreased clot retraction, and they exhibit ineffective Ca2+ signaling and thrombus formation in vivo. Thus, PTP-1B is an essential positive regulator of the initiation of outside-in αIIbβ3 signaling in platelets.
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Abstract
This review summarizes recent developments in our understanding of the molecular basis of platelet activation by two distinct types of surface receptor, the immunoglobulin GPVI, and the integrin alphaIIb beta3 (also known as GPIIbIIIa). These two classes of receptor signal through similar yet distinct tyrosine kinase-based signaling cascades leading to activation of phospholipase C gamma2. The significance of these signaling cascades in platelet adhesion and platelet aggregation at arterial rates of shear is discussed.
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Affiliation(s)
- S P Watson
- Division of Medical Sciences, Centre for Cardiovascular Sciences, Institute of Biomedical Research, The Medical School, University of Birmingham, Birmingham, UK.
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