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Griffin MS, Dahlgren AR, Nagaswami C, Litvinov RI, Keeler K, Madenjian C, Fuentes R, Fish RJ, Neerman-Arbez M, Holinstat M, Adili R, Weisel JW, Shavit JA. Composition of thrombi in zebrafish: similarities and distinctions with mammals. J Thromb Haemost 2024; 22:1056-1068. [PMID: 38160724 DOI: 10.1016/j.jtha.2023.12.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/28/2023] [Accepted: 12/14/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND Blood clots are primarily composed of red blood cells (RBCs), platelets/thrombocytes, and fibrin. Despite the similarities observed between mammals and zebrafish, the composition of fish thrombi is not as well known. OBJECTIVES To analyze the formation of zebrafish blood clots ex vivo and arterial and venous thrombi in vivo. METHODS Transgenic zebrafish lines and laser-mediated endothelial injury were used to determine the relative ratio of RBCs and thrombocytes in clots. Scanning electron and confocal microscopy provided high-resolution images of the structure of adult and larval clots. Adult and larval thrombocyte spreading on fibrinogen was evaluated ex vivo. RESULTS RBCs were present in arterial and venous thrombi, making up the majority of cells in both circulations. However, bloodless mutant fish demonstrated that fibrin clots can form in vivo in the absence of blood cells. Scanning electron and confocal microscopy showed that larval and adult zebrafish thrombi and mammalian thrombi look surprisingly similar externally and internally, even though the former have nucleated RBCs and thrombocytes. Although adult thrombocytes spread on fibrinogen, we found that larval cells do not fully activate without the addition of plasma from adult fish, suggesting a developmental deficiency of a plasma activating factor. Finally, mutants lacking αIIbβ3 demonstrated that this integrin mediates thrombocyte spreading on fibrinogen. CONCLUSION Our data showed strong conservation of arterial and venous and clot/thrombus formation across species, including developmental regulation of thrombocyte function. This correlation supports the possibility that mammals also do not absolutely require circulating cells to form fibrin clots in vivo.
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Affiliation(s)
- Megan S Griffin
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA
| | - Anna R Dahlgren
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA
| | - Chandrasekaran Nagaswami
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Rustem I Litvinov
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Kevin Keeler
- US Geological Survey Great Lakes Science Center, Ann Arbor, Michigan, USA
| | - Charles Madenjian
- US Geological Survey Great Lakes Science Center, Ann Arbor, Michigan, USA
| | - Ricardo Fuentes
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Richard J Fish
- Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Marguerite Neerman-Arbez
- Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Michael Holinstat
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, USA
| | - Reheman Adili
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, USA
| | - John W Weisel
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Jordan A Shavit
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA; Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA.
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2
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Xin H, Huang J, Song Z, Mao J, Xi X, Shi X. Structure, signal transduction, activation, and inhibition of integrin αIIbβ3. Thromb J 2023; 21:18. [PMID: 36782235 PMCID: PMC9923933 DOI: 10.1186/s12959-023-00463-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 02/06/2023] [Indexed: 02/15/2023] Open
Abstract
Integrins are heterodimeric receptors comprising α and β subunits. They are expressed on the cell surface and play key roles in cell adhesion, migration, and growth. Several types of integrins are expressed on the platelets, including αvβ3, αIIbβ3, α2β1, α5β1, and α6β1. Among these, physically αIIbβ3 is exclusively expressed on the platelet surface and their precursor cells, megakaryocytes. αIIbβ3 adopts at least three conformations: i) bent-closed, ii) extended-closed, and iii) extended-open. The transition from conformation i) to iii) occurs when αIIbβ3 is activated by stimulants. Conformation iii) possesses a high ligand affinity, which triggers integrin clustering and platelet aggregation. Platelets are indispensable for maintaining vascular system integrity and preventing bleeding. However, excessive platelet activation can result in myocardial infarction (MI) and stroke. Therefore, finding a novel strategy to stop bleeding without accelerating the risk of thrombosis is important. Regulation of αIIbβ3 activation is vital for this strategy. There are a large number of molecules that facilitate or inhibit αIIbβ3 activation. The interference of these molecules can accurately control the balance between hemostasis and thrombosis. This review describes the structure and signal transduction of αIIbβ3, summarizes the molecules that directly or indirectly affect integrin αIIbβ3 activation, and discusses some novel antiαIIbβ3 drugs. This will advance our understanding of the activation of αIIbβ3 and its essential role in platelet function and tumor development.
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Affiliation(s)
- Honglei Xin
- grid.452511.6Department of Hematology, Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210003 China
| | - Jiansong Huang
- grid.13402.340000 0004 1759 700XDepartment of Hematology, The First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang, Hangzhou 310003 China ,grid.412277.50000 0004 1760 6738Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Zhiqun Song
- grid.412676.00000 0004 1799 0784Jiangsu Province People’s Hospital and Nanjing Medical University First Affiliated Hospital, Nanjing, Jiangsu 210029 China
| | - Jianhua Mao
- grid.412277.50000 0004 1760 6738Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Xiaodong Xi
- Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| | - Xiaofeng Shi
- Department of Hematology, Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210003, China. .,Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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Hamad MA, Krauel K, Schanze N, Gauchel N, Stachon P, Nuehrenberg T, Zurek M, Duerschmied D. Platelet Subtypes in Inflammatory Settings. Front Cardiovasc Med 2022; 9:823549. [PMID: 35463762 PMCID: PMC9021412 DOI: 10.3389/fcvm.2022.823549] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 03/09/2022] [Indexed: 12/24/2022] Open
Abstract
In addition to their essential role in hemostasis and thrombosis, platelets also modulate inflammatory reactions and immune responses. This is achieved by specialized surface receptors as well as secretory products including inflammatory mediators and cytokines. Platelets can support and facilitate the recruitment of leukocytes into inflamed tissue. The various properties of platelet function make it less surprising that circulating platelets are different within one individual. Platelets have different physical properties leading to distinct subtypes of platelets based either on their function (procoagulant, aggregatory, secretory) or their age (reticulated/immature, non-reticulated/mature). To understand the significance of platelet phenotypic variation, qualitatively distinguishable platelet phenotypes should be studied in a variety of physiological and pathological circumstances. The advancement in proteomics instrumentation and tools (such as mass spectrometry-driven approaches) improved the ability to perform studies beyond that of foundational work. Despite the wealth of knowledge around molecular processes in platelets, knowledge gaps in understanding platelet phenotypes in health and disease exist. In this review, we report an overview of the role of platelet subpopulations in inflammation and a selection of tools for investigating the role of platelet subpopulations in inflammation.
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Affiliation(s)
- Muataz Ali Hamad
- Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg im Breisgau, Germany
- Faculty of Biology, University of Freiburg, Freiburg im Breisgau, Germany
| | - Krystin Krauel
- Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
- Department of Cardiology, Angiology, Haemostaseology, and Medical Intensive Care, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Nancy Schanze
- Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
- Department of Cardiology, Angiology, Haemostaseology, and Medical Intensive Care, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Nadine Gauchel
- Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Peter Stachon
- Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Thomas Nuehrenberg
- Department of Cardiology and Angiology II, Heart Center, Faculty of Medicine, University of Freiburg, Bad Krozingen, Germany
| | - Mark Zurek
- Department of Cardiology and Angiology II, Heart Center, Faculty of Medicine, University of Freiburg, Bad Krozingen, Germany
| | - Daniel Duerschmied
- Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
- Department of Cardiology, Angiology, Haemostaseology, and Medical Intensive Care, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- European Center for AngioScience (ECAS) and German Center for Cardiovascular Research (DZHK) Partner Site Heidelberg/Mannheim, Mannheim, Germany
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De Kock L, Freson K. The (Patho)Biology of SRC Kinase in Platelets and Megakaryocytes. ACTA ACUST UNITED AC 2020; 56:medicina56120633. [PMID: 33255186 PMCID: PMC7759910 DOI: 10.3390/medicina56120633] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/17/2020] [Accepted: 11/21/2020] [Indexed: 02/07/2023]
Abstract
Proto-oncogene tyrosine-protein kinase SRC (SRC), as other members of the SRC family kinases (SFK), plays an important role in regulating signal transduction by different cell surface receptors after changes in the cellular environment. Here, we reviewed the role of SRC in platelets and megakaryocytes (MK). In platelets, inactive closed SRC is coupled to the β subunit of integrin αIIbβ3 while upon fibrinogen binding during platelet activation, αIIbβ3-mediated outside-in signaling is initiated by activation of SRC. Active open SRC now further stimulates many downstream effectors via tyrosine phosphorylation of enzymes, adaptors, and especially cytoskeletal components. Functional platelet studies using SRC knockout mice or broad spectrum SFK inhibitors pointed out that SRC mediates their spreading on fibrinogen. On the other hand, an activating pathological SRC missense variant E527K in humans that causes bleeding inhibits collagen-induced platelet activation while stimulating platelet spreading. The role of SRC in megakaryopoiesis is much less studied. SRC knockout mice have a normal platelet count though studies with SFK inhibitors point out that SRC could interfere with MK polyploidization and proplatelet formation but these inhibitors are not specific. Patients with the SRC E527K variant have thrombocytopenia due to hyperactive SRC that inhibits proplatelet formation after increased spreading of MK on fibrinogen and enhanced formation of podosomes. Studies in humans have contributed significantly to our understanding of SRC signaling in platelets and MK.
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Chaudhary PK, Kim S, Jee Y, Lee SH, Kim S. Characterization of Integrin αIIbβ3-Mediated Outside-in Signaling by Protein Kinase Cδ in Platelets. Int J Mol Sci 2020; 21:ijms21186563. [PMID: 32911704 PMCID: PMC7555476 DOI: 10.3390/ijms21186563] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 09/01/2020] [Accepted: 09/07/2020] [Indexed: 11/16/2022] Open
Abstract
Engagement of integrin αIIbβ3 promotes platelet-platelet interaction and stimulates outside-in signaling that amplifies activation. Protein kinase Cδ (PKCδ) is known to play an important role in platelet activation, but its role in outside-in signaling has not been established. In the present study, we determined the role of PKCδ and its signaling pathways in integrin αIIbβ3-mediated outside-in signaling in platelets using PKCδ-deficient platelets. Platelet spreading to immobilized fibrinogen resulted in PKCδ phosphorylation, suggesting that αIIbβ3 activation caused PKCδ activation. αIIbβ3-mediated phosphorylation of Akt was significantly inhibited in PKCδ -/- platelets, indicating a role of PKCδ in outside-in signaling. αIIbβ3-mediated PKCδ phosphorylation was inhibited by proline-rich tyrosine kinase 2 (Pyk2) selective inhibitor, suggesting that Pyk2 contributes to the regulation of PKCδ phosphorylation in outside-in signaling. Additionally, Src-family kinase inhibitor PP2 inhibited integrin-mediated Pyk2 and PKCδ phosphorylation. Lastly, platelet spreading was inhibited in PKCδ -/- platelets compared to the wild-type (WT) platelets, and clot retraction from PKCδ -/- platelets was markedly delayed, indicating that PKCδ is involved in the regulation of αIIbβ3-dependent interactivities with cytoskeleton elements. Together, these results provide evidence that PKCδ plays an important role in outside-in signaling, which is regulated by Pyk2 in platelets.
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Affiliation(s)
- Preeti Kumari Chaudhary
- College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea; (P.K.C.); (S.K.); (S.-H.L.)
| | - Sanggu Kim
- College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea; (P.K.C.); (S.K.); (S.-H.L.)
| | - Youngheun Jee
- College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju 63243, Korea;
| | - Seung-Hun Lee
- College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea; (P.K.C.); (S.K.); (S.-H.L.)
| | - Soochong Kim
- College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea; (P.K.C.); (S.K.); (S.-H.L.)
- Correspondence: ; Tel.: +82-43-249-1846
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6
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Huang J, Fan H, Yin X, Huang F. Isolation of a Novel Metalloproteinase from Agkistrodon Venom and Its Antithrombotic Activity Analysis. Int J Mol Sci 2019; 20:E4088. [PMID: 31438579 PMCID: PMC6747553 DOI: 10.3390/ijms20174088] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/15/2019] [Accepted: 08/18/2019] [Indexed: 12/12/2022] Open
Abstract
Snake venom contains large amounts of active proteins and peptides. In this study, a novel snake protein, metalloproteinase SP, was successfully isolated from the venom of Agkistrodon acutus by multi-gel chromatography. The isolated protein exhibits anti-platelet aggregation activity. Animal experiments showed that it exhibited defibration, anticoagulation, and antithrombotic effects and contributes to improved blood rheology and antiplatelet aggregation. In vivo experiments demonstrated that it prolonged clotting time, partial thromboplastin time, prothrombin time, thrombin time, fibrinogen time and reduced fibrinogen content of mice. Also, metalloproteinase SP inhibited carrageenan-induced tail thrombosis, ADP-induced acute pulmonary embolism, and ADP, Arachidonic acid (AA), or collagen-induced platelet aggregation. In vitro experiments showed that the protein cleaved the α, β, and γ chains of fibrinogen. Metabolomic analysis upon metalloproteinase SP treatment revealed that 14 metabolites, which are mainly involved in phenylalanine, tyrosine, and tryptophan biosynthesis, responded to metalloproteinase SP treatment. In summary, the isolated snake venom protein inhibits formation of acute pulmonary embolism probably through regulating and restoring perturbed energy, lipid, and amino acid metabolism.
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Affiliation(s)
- Jin Huang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Hui Fan
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Xiaojian Yin
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
- Chinese Medicine College, China Pharmaceutical University, Nanjing 210009, China.
| | - Fang Huang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
- Chinese Medicine College, China Pharmaceutical University, Nanjing 210009, China.
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7
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Laurent PA, Hechler B, Solinhac R, Ragab A, Cabou C, Anquetil T, Severin S, Denis CV, Mangin PH, Vanhaesebroeck B, Payrastre B, Gratacap MP. Impact of PI3Kα (Phosphoinositide 3-Kinase Alpha) Inhibition on Hemostasis and Thrombosis. Arterioscler Thromb Vasc Biol 2018; 38:2041-2053. [PMID: 30354258 DOI: 10.1161/atvbaha.118.311410] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective- PI3Kα (phosphoinositide 3-kinase alpha) is a therapeutic target in oncology, but its role in platelets and thrombosis remains ill characterized. In this study, we have analyzed the role of PI3Kα in vitro, ex vivo, and in vivo in 2 models of arterial thrombosis. Approach and Results- Using mice selectively deficient in p110α in the megakaryocyte lineage and isoform-selective inhibitors, we confirm that PI3Kα is not mandatory but participates to thrombus growth over a collagen matrix at arterial shear rate. Our data uncover a role for PI3Kα in low-level activation of the GP (glycoprotein) VI-collagen receptor by contributing to ADP secretion and in turn full activation of PI3Kβ and Akt/PKB (protein kinase B). This effect was no longer observed at high level of GP VI agonist concentration. Our study also reveals that over a vWF (von Willebrand factor) matrix, PI3Kα regulates platelet stationary adhesion contacts under arterial flow through its involvement in the outside-in signaling of vWF-engaged αIIbβ3 integrin. In vivo, absence or inhibition of PI3Kα resulted in a modest but significant decrease in thrombus size after superficial injuries of mouse mesenteric arteries and an increased time to arterial occlusion after carotid lesion, without modification in the tail bleeding time. Considering the more discrete and nonredundant role of PI3Kα compared with PI3Kβ, selective PI3Kα inhibitors are unlikely to increase the bleeding risk at least in the absence of combination with antiplatelet drugs or thrombopenia. Conclusions- This study provides mechanistic insight into the role of PI3Kα in platelet activation and arterial thrombosis.
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Affiliation(s)
- Pierre-Alexandre Laurent
- From the INSERM, UMR-S1048, Université Toulouse III, France (P.-A.L., R.S., A.R., C.C., T.A., S.S., B.P., M.-P.G.)
| | - Béatrice Hechler
- INSERM, EFS Grand Est, BPPS UMR-S 949, FMTS, Université de Strasbourg, France (B.H., P.H.M.)
| | - Romain Solinhac
- From the INSERM, UMR-S1048, Université Toulouse III, France (P.-A.L., R.S., A.R., C.C., T.A., S.S., B.P., M.-P.G.)
| | - Ashraf Ragab
- From the INSERM, UMR-S1048, Université Toulouse III, France (P.-A.L., R.S., A.R., C.C., T.A., S.S., B.P., M.-P.G.)
| | - Cendrine Cabou
- From the INSERM, UMR-S1048, Université Toulouse III, France (P.-A.L., R.S., A.R., C.C., T.A., S.S., B.P., M.-P.G.)
| | - Typhaine Anquetil
- From the INSERM, UMR-S1048, Université Toulouse III, France (P.-A.L., R.S., A.R., C.C., T.A., S.S., B.P., M.-P.G.)
| | - Sonia Severin
- From the INSERM, UMR-S1048, Université Toulouse III, France (P.-A.L., R.S., A.R., C.C., T.A., S.S., B.P., M.-P.G.)
| | - Cécile V Denis
- INSERM, UMR-S 1176, University of Paris-Sud, Université Paris-Saclay, France (C.V.D.)
| | - Pierre H Mangin
- INSERM, EFS Grand Est, BPPS UMR-S 949, FMTS, Université de Strasbourg, France (B.H., P.H.M.)
| | - Bart Vanhaesebroeck
- Cell Signaling, UCL Cancer Institute, University College London, United Kingdom (B.V.)
| | - Bernard Payrastre
- From the INSERM, UMR-S1048, Université Toulouse III, France (P.-A.L., R.S., A.R., C.C., T.A., S.S., B.P., M.-P.G.)
- CHU de Toulouse, Laboratoire d'Hématologie, France (B.P.)
| | - Marie-Pierre Gratacap
- From the INSERM, UMR-S1048, Université Toulouse III, France (P.-A.L., R.S., A.R., C.C., T.A., S.S., B.P., M.-P.G.)
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Cui Y, Zhou F, Bai L, Wei L, Tan J, Zeng Z, Song Q, Chen J, Huang N. SEMA4D-heparin Complexes Immobilized on Titanium Surfaces Have Anticoagulant, Cell-Migration-Promoting, and Immunoregulatory Effects. ACS Biomater Sci Eng 2018; 4:1598-1608. [PMID: 33445317 DOI: 10.1021/acsbiomaterials.8b00098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Soluble semaphorin 4D (SEMA4D) is a 120 kDa transmembrane protein, which belongs to the semaphorin family of axon guidance molecules that act primarily axonal repellents. SEMA4D elicits its migration-promoting and immunomodulatory effects through activation of PLXNB1 and CD72, respectively. In this study, SEMA4D combined with heparin were adsorbed onto cationic surfaces. The biocompatibility evaluation results indicated that the SEMA4D-heparin-modified surfaces displayed less platelet adhesion and activation, prolonged activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) and reduced fibrinogen gamma chain (FGG) exposure and fibrinogen adhesion. Additionally, endothelial cells (ECs) showed improved adhesion density and proliferation activity on the SEMA4D-heparin-modified surfaces. Chemotactic and haptotaxis assays indicated a highly guided migration for ECs on the modified surfaces. The immunological tests revealed that the SEMA4D-heparin complexes had a positive immunomodulatory effect on macrophages and promoted macrophages polarization into M2 phenotypes. Overall, the results suggested that the SEMA4D-heparin complexes can be a potential therapeutic agent to promote tissue healing and accelerate in situ endothelialization with minimal side effects and positive immunomodulatory effect.
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Affiliation(s)
| | - Feng Zhou
- Institute of Aeronautics and Astronautics, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China
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Mangin PH, Onselaer MB, Receveur N, Le Lay N, Hardy AT, Wilson C, Sanchez X, Loyau S, Dupuis A, Babar AK, Miller JL, Philippou H, Hughes CE, Herr AB, Ariëns RA, Mezzano D, Jandrot-Perrus M, Gachet C, Watson SP. Immobilized fibrinogen activates human platelets through glycoprotein VI. Haematologica 2018; 103:898-907. [PMID: 29472360 PMCID: PMC5927996 DOI: 10.3324/haematol.2017.182972] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 02/13/2018] [Indexed: 12/27/2022] Open
Abstract
Glycoprotein VI, a major platelet activation receptor for collagen and fibrin, is considered a particularly promising, safe antithrombotic target. In this study, we show that human glycoprotein VI signals upon platelet adhesion to fibrinogen. Full spreading of human platelets on fibrinogen was abolished in platelets from glycoprotein VI- deficient patients suggesting that fibrinogen activates platelets through glycoprotein VI. While mouse platelets failed to spread on fibrinogen, human-glycoprotein VI-transgenic mouse platelets showed full spreading and increased Ca2+ signaling through the tyrosine kinase Syk. Direct binding of fibrinogen to human glycoprotein VI was shown by surface plasmon resonance and by increased adhesion to fibrinogen of human glycoprotein VI-transfected RBL-2H3 cells relative to mock-transfected cells. Blockade of human glycoprotein VI with the Fab of the monoclonal antibody 9O12 impaired platelet aggregation on preformed platelet aggregates in flowing blood independent of collagen and fibrin exposure. These results demonstrate that human glycoprotein VI binds to immobilized fibrinogen and show that this contributes to platelet spreading and platelet aggregation under flow.
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Affiliation(s)
- Pierre H Mangin
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S 1255, FMTS, France
| | - Marie-Blanche Onselaer
- Institute of Cardiovascular Sciences, IBR Building, College of Medical and Dental Sciences, University of Birmingham, UK
| | - Nicolas Receveur
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S 1255, FMTS, France
| | - Nicolas Le Lay
- Université de Paris Diderot, INSERM UMR_S1148, Hôpital Bichat, Paris, France
| | - Alexander T Hardy
- Institute of Cardiovascular Sciences, IBR Building, College of Medical and Dental Sciences, University of Birmingham, UK
| | - Clare Wilson
- Thrombosis and Tissue Repair Group, Institute of Cardiovascular and Metabolic Medicine, University of Leeds, UK
| | - Ximena Sanchez
- Laboratorio de Hemostasia, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Stéphane Loyau
- Université de Paris Diderot, INSERM UMR_S1148, Hôpital Bichat, Paris, France
| | - Arnaud Dupuis
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S 1255, FMTS, France
| | - Amir K Babar
- Division of Immunobiology, Center for Systems Immunology & Division of Infectious Diseases, Cincinnati, OH, USA
| | - Jeanette Lc Miller
- Division of Immunobiology, Center for Systems Immunology & Division of Infectious Diseases, Cincinnati, OH, USA
| | - Helen Philippou
- Thrombosis and Tissue Repair Group, Institute of Cardiovascular and Metabolic Medicine, University of Leeds, UK
| | - Craig E Hughes
- Institute of Cardiovascular Sciences, IBR Building, College of Medical and Dental Sciences, University of Birmingham, UK.,Institute for Cardiovascular and Metabolic Research, Harborne Building, University of Reading, UK
| | - Andrew B Herr
- Division of Immunobiology, Center for Systems Immunology & Division of Infectious Diseases, Cincinnati, OH, USA
| | - Robert As Ariëns
- Thrombosis and Tissue Repair Group, Institute of Cardiovascular and Metabolic Medicine, University of Leeds, UK
| | - Diego Mezzano
- Laboratorio de Hemostasia, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Martine Jandrot-Perrus
- Université de Paris Diderot, INSERM UMR_S1148, Hôpital Bichat, Paris, France.,Acticor Biotech, Hôpital Bichat, INSERM, UMR-S 1148, Paris, France
| | - Christian Gachet
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S 1255, FMTS, France
| | - Steve P Watson
- Institute of Cardiovascular Sciences, IBR Building, College of Medical and Dental Sciences, University of Birmingham, UK .,Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Midlands, UK
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10
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Superior integrin activating capacity and higher adhesion to fibrinogen matrix in buffy coat-derived platelet concentrates (PCs) compared to PRP-PCs. Transfus Apher Sci 2018; 57:76-81. [DOI: 10.1016/j.transci.2017.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/12/2017] [Accepted: 12/12/2017] [Indexed: 11/19/2022]
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11
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Procoagulant platelets: generation, function, and therapeutic targeting in thrombosis. Blood 2017; 130:2171-2179. [DOI: 10.1182/blood-2017-05-787259] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 09/12/2017] [Indexed: 11/20/2022] Open
Abstract
Abstract
Current understanding of how platelets localize coagulation to wound sites has come mainly from studies of a subpopulation of activated platelets. In this review, we summarize data from the last 4 decades that have described these platelets with a range of descriptive titles and attributes. We identify striking overlaps in the reported characteristics of these platelets, which imply a single subpopulation of versatile platelets and thus suggest that their commonality requires unification of their description. We therefore propose the term procoagulant platelet as the unifying terminology. We discuss the agonist requirements and molecular drivers for the dramatic morphological transformation platelets undergo when becoming procoagulant. Finally, we provide perspectives on the biomarker potential of procoagulant platelets for thrombotic events as well as on the possible clinical benefits of inhibitors of carbonic anhydrase enzymes and the water channel Aquaporin-1 for targeting this subpopulation of platelets as antiprocoagulant antithrombotics.
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12
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Pugh N, Maddox BD, Bihan D, Taylor KA, Mahaut-Smith MP, Farndale RW. Differential integrin activity mediated by platelet collagen receptor engagement under flow conditions. Thromb Haemost 2017; 117:1588-1600. [PMID: 28536721 PMCID: PMC6291897 DOI: 10.1160/th16-12-0906] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/22/2017] [Indexed: 11/15/2022]
Abstract
The platelet receptors glycoprotein (Gp)VI, integrin α
2
β
1
and GpIb/V/IX mediate platelet adhesion and activation during thrombogenesis. Increases of intracellular Ca
2+
([Ca
2+
]
i
) are key signals during platelet activation; however, their relative importance in coupling different collagen receptors to functional responses under shear conditions remains unclear. To study shear-dependent, receptor-specific platelet responses, we used collagen or combinations of receptor-specific collagen-mimetic peptides as substrates for platelet adhesion and activation in whole human blood under arterial flow conditions and compared real-time and endpoint parameters of thrombus formation alongside [Ca
2+
]
i
measurements using confocal imaging. All three collagen receptors coupled to [Ca
2+
]
i
signals, but these varied in amplitude and temporal pattern alongside variable integrin activation. GpVI engagement produced large, sustained [Ca
2+
]
i
signals leading to realtime increases in integrins α
2
β
1
− and α
IIb
β
3
-mediated platelet adhesion. α
IIb
β
3
-dependent platelet aggregation was dependent on P
2
Y
12
signalling. Co-engagement of α
2
β
1
and GpIb/V/IX generated transient [Ca
2+
]
i
spikes and low amplitude [Ca
2+
]
i
responses that potentiated GpVI-dependent [Ca
2+
]
i
signalling. Therefore α
2
β
1
GpIb/V/IX and GpVI synergise to generate [Ca
2+
]
i
signals that regulate platelet behaviour and thrombus formation. Antagonism of secondary signalling pathways reveals distinct, separate roles for α
IIb
β
3
in stable platelet adhesion and aggregation.
Supplementary Material to this article is available online at
www.thrombosis-online.com
.
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Affiliation(s)
- Nicholas Pugh
- Nicholas Pugh, Department of Biomedical and Forensic Sciences, Anglia Ruskin University, Cambridge, CB1 1PT, UK, Tel.: +44 8451962661, E-mail:
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13
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Battram AM, Durrant TN, Agbani EO, Heesom KJ, Paul DS, Piatt R, Poole AW, Cullen PJ, Bergmeier W, Moore SF, Hers I. The Phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) Binder Rasa3 Regulates Phosphoinositide 3-kinase (PI3K)-dependent Integrin αIIbβ3 Outside-in Signaling. J Biol Chem 2017; 292:1691-1704. [PMID: 27903653 PMCID: PMC5290945 DOI: 10.1074/jbc.m116.746867] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 11/14/2016] [Indexed: 11/16/2022] Open
Abstract
The class I PI3K family of lipid kinases plays an important role in integrin αIIbβ3 function, thereby supporting thrombus growth and consolidation. Here, we identify Ras/Rap1GAP Rasa3 (GAP1IP4BP) as a major phosphatidylinositol 3,4,5-trisphosphate-binding protein in human platelets and a key regulator of integrin αIIbβ3 outside-in signaling. We demonstrate that cytosolic Rasa3 translocates to the plasma membrane in a PI3K-dependent manner upon activation of human platelets. Expression of wild-type Rasa3 in integrin αIIbβ3-expressing CHO cells blocked Rap1 activity and integrin αIIbβ3-mediated spreading on fibrinogen. In contrast, Rap1GAP-deficient (P489V) and Ras/Rap1GAP-deficient (R371Q) Rasa3 had no effect. We furthermore show that two Rasa3 mutants (H794L and G125V), which are expressed in different mouse models of thrombocytopenia, lack both Ras and Rap1GAP activity and do not affect integrin αIIbβ3-mediated spreading of CHO cells on fibrinogen. Platelets from thrombocytopenic mice expressing GAP-deficient Rasa3 (H794L) show increased spreading on fibrinogen, which in contrast to wild-type platelets is insensitive to PI3K inhibitors. Together, these results support an important role for Rasa3 in PI3K-dependent integrin αIIbβ3-mediated outside-in signaling and cell spreading.
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Affiliation(s)
- Anthony M Battram
- From the School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Tom N Durrant
- From the School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Ejaife O Agbani
- From the School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Kate J Heesom
- School of Biochemistry, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - David S Paul
- the McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514
| | - Raymond Piatt
- the McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514
| | - Alastair W Poole
- From the School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Peter J Cullen
- School of Biochemistry, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Wolfgang Bergmeier
- the McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514; Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514
| | - Samantha F Moore
- From the School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Ingeborg Hers
- From the School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom.
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14
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Shi X, Yang J, Cui X, Huang J, Long Z, Zhou Y, Liu P, Tao L, Ruan Z, Xiao B, Zhang W, Li D, Dai K, Mao J, Xi X. Functional Effect of the Mutations Similar to the Cleavage during Platelet Activation at Integrin β3 Cytoplasmic Tail when Expressed in Mouse Platelets. PLoS One 2016; 11:e0166136. [PMID: 27851790 PMCID: PMC5112943 DOI: 10.1371/journal.pone.0166136] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 10/24/2016] [Indexed: 12/31/2022] Open
Abstract
Previous studies in Chinese hamster ovary cells showed that truncational mutations of β3 at sites of F754 and Y759 mimicking calpain cleavage regulate integrin signaling. The roles of the sequence from F754 to C-terminus and the conservative N756ITY759 motif in platelet function have yet to be elaborated. Mice expressing β3 with F754 and Y759 truncations, or NITY deletion (β3-ΔTNITYRGT, β3-ΔRGT, or β3-ΔNITY) were established through transplanting the homozygous β3-deficient mouse bone marrow cells infected by the GFP tagged MSCV MigR1 retroviral vector encoding different β3 mutants into lethally radiated wild-type mice. The platelets were harvested for soluble fibrinogen binding and platelet spreading on immobilized fibrinogen. Platelet adhesion on fibrinogen- and collagen-coated surface under flow was also tested to assess the ability of the platelets to resist hydrodynamic drag forces. Data showed a drastic inhibition of the β3-ΔTNITYRGT platelets to bind soluble fibrinogen and spread on immobilized fibrinogen in contrast to a partially impaired fibrinogen binding and an almost unaffected spreading exhibited in the β3-ΔNITY platelets. Behaviors of the β3-ΔRGT platelets were consistent with the previous observations in the β3-ΔRGT knock-in platelets. The adhesion impairment of platelets with the β3 mutants under flow was in different orders of magnitude shown as: β3-ΔTNITYRGT>β3-ΔRGT>β3-ΔNITY to fibrinogen-coated surface, and β3-ΔTNITYRGT>β3-ΔNITY>β3-ΔRGT to collagen-coated surface. To evaluate the interaction of the β3 mutants with signaling molecules, GST pull-down and immunofluorescent assays were performed. Results showed that β3-ΔRGT interacted with kindlin but not c-Src, β3-ΔNITY interacted with c-Src but not kindlin, while β3-ΔTNITYRGT did not interact with both proteins. This study provided evidence in platelets at both static and flow conditions that the calpain cleavage-related sequences of integrin β3, i.e. T755NITYRGT762, R760GT762, and N756ITY759 participate in bidirectional, outside-in, and inside-out signaling, respectively and the association of c-Src or kindlin with β3 integrin may regulate these processes.
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Affiliation(s)
- Xiaofeng Shi
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Department of Hematology, Affiliated Hospital of Jiangsu University, Zhenjiang, China
| | - Jichun Yang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Xiongying Cui
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Jiansong Huang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Department of Hematology, Institute of Hematology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Zhangbiao Long
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Yulan Zhou
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Ping Liu
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Lanlan Tao
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Zheng Ruan
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Bing Xiao
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Wei Zhang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Dongya Li
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Department of Hematology, Affiliated Hospital of Jiangsu University, Zhenjiang, China
| | - Kesheng Dai
- Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, 215006, China
| | - Jianhua Mao
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- * E-mail: (JM); (XX)
| | - Xiaodong Xi
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Sino-French Research Center for Life Sciences and Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- * E-mail: (JM); (XX)
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15
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Abstract
Pannexin-1 (Panx1) forms anion-selective channels with a permeability up to 1 kDa and represents a pathway for the release of cytosolic ATP. Several structurally similar connexin (Cx) proteins have been identified in platelets and shown to play roles in haemostasis and thrombosis. More recently, functional Panx1 channels have been demonstrated on the surface of human platelets [Taylor et al. (2014) J. Thromb. Haemost. 12, 987-998]. Since their identification in the year 2000, several mechanisms have been reported to activate Panx1 channels, including mechanical stimulation, oxygen-glucose deprivation, a rise of [Ca2+]i, caspase cleavage and phosphorylation. Within this review, the regulation of Panx1 channels is discussed, with a focus on how they may contribute to platelet function.
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16
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Niki M, Nayak MK, Jin H, Bhasin N, Plow EF, Pandolfi PP, Rothman PB, Chauhan AK, Lentz SR. Dok-1 negatively regulates platelet integrin αIIbβ3 outside-in signalling and inhibits thrombosis in mice. Thromb Haemost 2016; 115:969-78. [PMID: 26790499 DOI: 10.1160/th15-05-0373] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 12/23/2015] [Indexed: 01/10/2023]
Abstract
Adaptor proteins play a critical role in the assembly of signalling complexes after engagement of platelet receptors by agonists such as collagen, ADP and thrombin. Recently, using proteomics, the Dok (downstream of tyrosine kinase) adapter proteins were identified in human and mouse platelets. In vitro studies suggest that Dok-1 binds to platelet integrin β3, but the underlying effects of Dok-1 on αIIbβ3 signalling, platelet activation and thrombosis remain to be elucidated. In the present study, using Dok-1-deficient (Dok-1-/-) mice, we determined the phenotypic role of Dok-1 in αIIbβ3 signalling. We found that platelets from Dok-1-/- mice displayed normal aggregation, activation of αIIbβ3 (assessed by binding of JON/A), P-selectin surface expression (assessed by anti-CD62P), and soluble fibrinogen binding. These findings indicate that Dok-1 does not affect "inside-out" platelet signalling. Compared with platelets from wild-type (WT) mice, platelets from Dok-1-/- mice exhibited increased clot retraction (p < 0.05 vs WT), increased PLCγ2 phosphorylation, and enhanced spreading on fibrinogen after thrombin stimulation (p < 0.01 vs WT), demonstrating that Dok-1 negatively regulates αIIbβ3 "outside-in" signalling. Finally, we found that Dok-1-/- mice exhibited significantly shortened bleeding times and accelerated carotid artery thrombosis in response to photochemical injury (p < 0.05 vs WT mice). We conclude that Dok-1 modulates thrombosis and haemostasis by negatively regulating αIIbβ3 outside-in signalling.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Steven R Lentz
- Steven R. Lentz, MD, PhD, Department of Internal Medicine, University of Iowa, C21 GH, 200 Hawkins Drive, Iowa City, IA 52242, USA, Tel.: +1 319 356 4048, Fax: +1 319 353 8383, E-mail:
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17
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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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18
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Restoration of responsiveness of phospholipase Cγ2-deficient platelets by enforced expression of phospholipase Cγ1. PLoS One 2015; 10:e0119739. [PMID: 25793864 PMCID: PMC4368822 DOI: 10.1371/journal.pone.0119739] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/15/2015] [Indexed: 01/21/2023] Open
Abstract
Receptor-mediated platelet activation requires phospholipase C (PLC) activity to elevate intracellular calcium and induce actin cytoskeleton reorganization. PLCs are classified into structurally distinct β, γ, δ, ε, ζ, and η isoforms. There are two PLCγ isoforms (PLCγ1, PLCγ2), which are critical for activation by tyrosine kinase-dependent receptors. Platelets express both PLCγ1 and PLCγ2. Although PLCγ2 has been shown to play a dominant role in platelet activation, the extent to which PLCγ1 contributes has not been evaluated. To ascertain the relative contributions of PLCγ1 and PLCγ2 to platelet activation, we generated conditionally PLCγ1-deficient, wild-type (WT), PLCγ2-deficient, and PLCγ1/PLCγ2 double-deficient mice and measured the ability of platelets to respond to different agonists. We found that PLCγ2 deficiency abrogated αIIbβ3-dependent platelet spreading, GPVI-dependent platelet aggregation, and thrombus formation on collagen-coated surfaces under shear conditions, which is dependent on both GPVI and αIIbβ3. Addition of exogenous ADP overcame defective spreading of PLCγ2-deficient platelets on immobilized fibrinogen, suggesting that PLCγ2 is required for granule secretion in response to αIIbβ3 ligation. Consistently, αIIbβ3-mediated release of granule contents was impaired in the absence of PLCγ2. In contrast, PLCγ1-deficient platelets spread and released granule contents normally on fibrinogen, exhibited normal levels of GPVI-dependent aggregation, and formed thrombi normally on collagen-coated surfaces. Interestingly, enforced expression of PLCγ1 fully restored GPVI-dependent aggregation and αIIbβ3-dependent spreading of PLCγ2-deficient platelets. We conclude that platelet activation through GPVI and αIIbβ3 utilizes PLCγ2 because PLCγ1 levels are insufficient to support responsiveness, but that PLCγ1 can restore responsiveness if expressed at levels normally achieved by PLCγ2.
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19
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Mountford JK, Petitjean C, Putra HWK, McCafferty JA, Setiabakti NM, Lee H, Tønnesen LL, McFadyen JD, Schoenwaelder SM, Eckly A, Gachet C, Ellis S, Voss AK, Dickins RA, Hamilton JR, Jackson SP. The class II PI 3-kinase, PI3KC2α, links platelet internal membrane structure to shear-dependent adhesive function. Nat Commun 2015; 6:6535. [PMID: 25779105 DOI: 10.1038/ncomms7535] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 02/05/2015] [Indexed: 12/29/2022] Open
Abstract
PI3KC2α is a broadly expressed lipid kinase with critical functions during embryonic development but poorly defined roles in adult physiology. Here we utilize multiple mouse genetic models to uncover a role for PI3KC2α in regulating the internal membrane reserve structure of megakaryocytes (demarcation membrane system) and platelets (open canalicular system) that results in dysregulated platelet adhesion under haemodynamic shear stress. Structural alterations in the platelet internal membrane lead to enhanced membrane tether formation that is associated with accelerated, yet highly unstable, thrombus formation in vitro and in vivo. Notably, agonist-induced 3-phosphorylated phosphoinositide production and cellular activation are normal in PI3KC2α-deficient platelets. These findings demonstrate an important role for PI3KC2α in regulating shear-dependent platelet adhesion via regulation of membrane structure, rather than acute signalling. These studies provide a link between the open canalicular system and platelet adhesive function that has relevance to the primary haemostatic and prothrombotic function of platelets.
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Affiliation(s)
- Jessica K Mountford
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Claire Petitjean
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Harun W Kusuma Putra
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Jonathan A McCafferty
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Natasha M Setiabakti
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Hannah Lee
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Lotte L Tønnesen
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - James D McFadyen
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Simone M Schoenwaelder
- 1] Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia [2] The Heart Research Institute and Charles Perkins Centre, The University of Sydney, Newtown 2050, Australia
| | - Anita Eckly
- Unité mixte de recherche S949 Institut National de la Santé et de la Recherche Médicale, Université de Strasbourg, Etablissement Français du Sang-Alsace 67000, Strasbourg, France
| | - Christian Gachet
- Unité mixte de recherche S949 Institut National de la Santé et de la Recherche Médicale, Université de Strasbourg, Etablissement Français du Sang-Alsace 67000, Strasbourg, France
| | - Sarah Ellis
- Sir Peter MacCallum Department of Oncology, Peter MacCallum Cancer Centre and The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Anne K Voss
- 1] Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Ross A Dickins
- 1] Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Justin R Hamilton
- Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Shaun P Jackson
- 1] Australian Centre for Blood Diseases, Monash University, Level 6, 89 Commercial Road, Melbourne, Victoria 3004, Australia [2] The Heart Research Institute and Charles Perkins Centre, The University of Sydney, Newtown 2050, Australia [3] Department of Molecular and Experimental Medicine, The Scripps Research Institute, San Diego, CA 92037, USA
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20
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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: 55] [Impact Index Per Article: 5.5] [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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21
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Hughan SC, Spring CM, Schoenwaelder SM, Sturgeon S, Alwis I, Yuan Y, McFadyen JD, Westein E, Goddard D, Ono A, Yamanashi Y, Nesbitt WS, Jackson SP. Dok-2 adaptor protein regulates the shear-dependent adhesive function of platelet integrin αIIbβ3 in mice. J Biol Chem 2014; 289:5051-60. [PMID: 24385425 DOI: 10.1074/jbc.m113.520148] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The Dok proteins are a family of adaptor molecules that have a well defined role in regulating cellular migration, immune responses, and tumor progression. Previous studies have demonstrated that Doks-1 to 3 are expressed in platelets and that Dok-2 is tyrosine-phosphorylated downstream of integrin αIIbβ3, raising the possibility that it participates in integrin αIIbβ3 outside-in signaling. We demonstrate that Dok-2 in platelets is primarily phosphorylated by Lyn kinase. Moreover, deficiency of Dok-2 leads to dysregulated integrin αIIbβ3-dependent cytosolic calcium flux and phosphatidylinositol(3,4)P2 accumulation. Although agonist-induced integrin αIIbβ3 affinity regulation was unaltered in Dok-2(-/-) platelets, Dok-2 deficiency was associated with a shear-dependent increase in integrin αIIbβ3 adhesive function, resulting in enhanced platelet-fibrinogen and platelet-platelet adhesive interactions under flow. This increase in adhesion was restricted to discoid platelets and involved the shear-dependent regulation of membrane tethers. Dok-2 deficiency was associated with an increased rate of platelet aggregate formation on thrombogenic surfaces, leading to accelerated thrombus growth in vivo. Overall, this study defines an important role for Dok-2 in regulating biomechanical adhesive function of discoid platelets. Moreover, they define a previously unrecognized prothrombotic mechanism that is not detected by conventional platelet function assays.
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Affiliation(s)
- Sascha C Hughan
- From the Australian Centre for Blood Diseases, Faculty of Medicine, Nursing, and Health Sciences, Monash University, Alfred Medical Research and Education Precinct, Commercial Road, Melbourne, Victoria 3004
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22
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Wang Y, Zhao L, Suzuki A, Lian L, Min SH, Wang Z, Litvinov RI, Stalker TJ, Yago T, Klopocki AG, Schmidtke DW, Yin H, Choi JK, McEver RP, Weisel JW, Hartwig JH, Abrams CS. Platelets lacking PIP5KIγ have normal integrin activation but impaired cytoskeletal-membrane integrity and adhesion. Blood 2013; 121:2743-52. [PMID: 23372168 PMCID: PMC3617636 DOI: 10.1182/blood-2012-07-445205] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 01/20/2013] [Indexed: 11/20/2022] Open
Abstract
Three isoforms of phosphatidylinositol-4-phosphate 5-kinase (PIP5KIα, PIP5KIβ, and PIP5KIγ) can each catalyze the final step in the synthesis of phosphatidylinositol-4,5-bisphosphate (PIP2), which in turn can be either converted to second messengers or bind directly to and thereby regulate proteins such as talin. A widely quoted model speculates that only p90, a longer splice form of platelet-specific PIP5KIγ, but not the shorter p87 PIP5KIγ, regulates the ligand-binding activity of integrins via talin. However, when we used mice genetically engineered to lack only p90 PIP5KIγ, we found that p90 PIP5KIγ is not critical for integrin activation or platelet adhesion on collagen. However, p90 PIP5KIγ-null platelets do have impaired anchoring of their integrins to the underlying cytoskeleton. Platelets lacking both the p90 and p87 PIP5KIγ isoforms had normal integrin activation and actin dynamics, but impaired anchoring of their integrins to the cytoskeleton. Most importantly, they formed weak shear-resistant adhesions ex vivo and unstable vascular occlusions in vivo. Together, our studies demonstrate that, although PIP5KIγ is essential for normal platelet function, individual isoforms of PIP5KIγ fulfill unique roles for the integrin-dependent integrity of the membrane cytoskeleton and for the stabilization of platelet adhesion.
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Affiliation(s)
- Yanfeng Wang
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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23
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van der Meijden PEJ, Feijge MAH, Swieringa F, Gilio K, Nergiz-Unal R, Hamulyák K, Heemskerk JWM. Key role of integrin α(IIb)β (3) signaling to Syk kinase in tissue factor-induced thrombin generation. Cell Mol Life Sci 2012; 69:3481-92. [PMID: 22669259 PMCID: PMC3445795 DOI: 10.1007/s00018-012-1033-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 04/18/2012] [Accepted: 05/10/2012] [Indexed: 11/23/2022]
Abstract
The fibrin(ogen) receptor, integrin αIIbβ3, has a well-established role in platelet spreading, aggregation and clot retraction. How αIIbβ3 contributes to platelet-dependent coagulation is less well resolved. Here, we demonstrate that the potent suppressing effect of clinically used αIIbβ3 blockers on tissue factor-induced thrombin generation is linked to diminished platelet Ca2+ responses and phosphatidylserine (PS) exposure. The same blockers suppress these responses in platelets stimulated with collagen and thrombin receptor agonists, whereas added fibrinogen potentiates these responses. In platelets spreading on fibrinogen, outside-in αIIbβ3 signaling similarly enhances thrombin-induced Ca2+ rises and PS exposure. These responses are reduced in αIIbβ3-deficient platelets from patients with Glanzmann’s thrombasthenia. Furthermore, the contribution of αIIbβ3 to tissue factor-induced platelet Ca2+ rises, PS exposure and thrombin generation in plasma are fully dependent on Syk kinase activity. Tyrosine phosphorylation analysis confirms a key role of Syk activation, which is largely but not exclusively dependent on αIIbβ3 activation. It is concluded that the majority of tissue factor-induced procoagulant activity of platelets relies on Syk activation and ensuing Ca2+ signal generation, and furthermore that a considerable part of Syk activation relies on αIIbβ3 signaling. These results hence point to a novel role of Syk in integrin-dependent thrombin generation.
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Affiliation(s)
- Paola E J van der Meijden
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands.
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24
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Fennewald SM, Kantara C, Sastry SK, Resto VA. Laminin interactions with head and neck cancer cells under low fluid shear conditions lead to integrin activation and binding. J Biol Chem 2012; 287:21058-66. [PMID: 22547070 DOI: 10.1074/jbc.m112.360313] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Lymphatic metastasis of cancer cells involves movement from the primary tumor site to the lymph node, where the cells must be able to productively lodge and grow. It is there that tumor cells encounter cellular and non-cellular constituent elements that make up the lymph node parenchyma. Our work shows that head and neck squamous cell carcinoma (HNSCC) cell lines are able to bind to laminin, fibronectin, vitronectin, and hyaluronic acid, which are extracellular matrix elements within the lymph node parenchyma. HNSCC cell lines bound to laminin under lymphodynamic low shear stress (0.07 dynes/cm(2)), consistent with lymph flow via β1 integrins, including α2β1, α3β1, and α6β1. Binding occurred in the presence of shear stress and not in the absence of flow. Additionally, tumor cell binding to laminin under flow did result in calcium signaling. Our data indicate a novel role for β1 integrin-mediated binding of HNSCC cells to laminin under conditions of lymphodynamic flow that results in intracellular calcium signaling within the cancer cell.
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Affiliation(s)
- Susan M Fennewald
- Department of Otolaryngology, UTMB Health, University of Texas Medical Branch, Galveston, Texas 77555-0521, USA
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25
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Goggs R, Poole AW. Platelet signaling-a primer. J Vet Emerg Crit Care (San Antonio) 2012; 22:5-29. [PMID: 22316389 DOI: 10.1111/j.1476-4431.2011.00704.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 11/25/2011] [Indexed: 12/28/2022]
Abstract
OBJECTIVE To review the receptors and signal transduction pathways involved in platelet plug formation and to highlight links between platelets, leukocytes, endothelium, and the coagulation system. DATA SOURCES Original studies, review articles, and book chapters in the human and veterinary medical fields. DATA SYNTHESIS Platelets express numerous surface receptors. Critical among these are glycoprotein VI, the glycoprotein Ib-IX-V complex, integrin α(IIb) β(3) , and the G-protein-coupled receptors for thrombin, ADP, and thromboxane. Activation of these receptors leads to various important functional events, in particular activation of the principal adhesion receptor α(IIb) β(3) . Integrin activation allows binding of ligands such as fibrinogen, mediating platelet-platelet interaction in the process of aggregation. Signals activated by these receptors also couple to 3 other important functional events, secretion of granule contents, change in cell shape through cytoskeletal rearrangement, and procoagulant membrane expression. These processes generate a stable thrombus to limit blood loss and promote restoration of endothelial integrity. CONCLUSIONS Improvements in our understanding of how platelets operate through their signaling networks are critical for diagnosis of unusual primary hemostatic disorders and for rational antithrombotic drug design.
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Affiliation(s)
- Robert Goggs
- School of Physiology and Pharmacology, Faculty of Medical and Veterinary Sciences, University of Bristol, UK.
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26
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Yi YH, Chang YS, Lin CH, Lew TS, Tang CY, Tseng WL, Tseng CP, Lo SJ. Integrin-mediated membrane blebbing is dependent on sodium-proton exchanger 1 and sodium-calcium exchanger 1 activity. J Biol Chem 2012; 287:10316-10324. [PMID: 22270364 DOI: 10.1074/jbc.m111.244962] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Integrin signaling and membrane blebbing modulate cell adhesion, spreading, and migration. However, the relationship between integrin signaling and membrane blebbing is unclear. Here, we show that an integrin-ligand interaction induces both membrane blebbing and changes in membrane permeability. Sodium-proton exchanger 1 (NHE1) and sodium-calcium exchanger 1 (NCX1) are membrane proteins located on the bleb membrane. Inhibition of NHE1 disrupts membrane blebbing and decreases changes in membrane permeability. However, inhibition of NCX1 enhances cell blebbing; cells become swollen because of NHE1 induced intracellular sodium accumulation. Our study found that NHE1 induced sodium influx is a driving force for membrane bleb growth, while sodium efflux (and calcium influx) induced by NCX1 in a reverse mode results in membrane bleb retraction. Together, these findings reveal a novel function for NHE1 and NCX1 in membrane blebbing and permeability, and establish a link between membrane blebbing and integrin signaling.
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Affiliation(s)
- Yung-Hsiang Yi
- Molecular Medicine Research Center, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan, R.O.C.; Department of Biomedical Sciences, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan, R.O.C
| | - Yu-Sun Chang
- Molecular Medicine Research Center, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan, R.O.C
| | - Chi-Hung Lin
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei 112, Taiwan, R.O.C
| | - Tien-Shen Lew
- Department of Physiology, National Yang-Ming University, Taipei 112, Taiwan, R.O.C., and
| | - Chih-Yung Tang
- Department of Physiology, National Taiwan University, Taipei 100, Taiwan, R.O.C
| | - Wei-Lien Tseng
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan, R.O.C
| | - Ching-Ping Tseng
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan, R.O.C
| | - Szecheng J Lo
- Department of Biomedical Sciences, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan, R.O.C.; Institute of Microbiology and Immunology, National Yang-Ming University, Taipei 112, Taiwan, R.O.C..
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A live cell micro-imaging technique to examine platelet calcium signaling dynamics under blood flow. Methods Mol Biol 2012; 788:73-89. [PMID: 22130701 DOI: 10.1007/978-1-61779-307-3_6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The platelet is a specialized adhesive cell that plays a key role in thrombus formation under both physiological and pathological blood flow conditions. Platelet adhesion and activation are dynamic processes associated with rapid morphological and functional changes, with the earliest signaling events occurring over a subsecond time-scale. The relatively small size of platelets combined with the dynamic nature of platelet adhesion under blood flow means that the investigation of platelet signaling events requires techniques with both high spatial discrimination and rapid temporal resolution. Unraveling the complex signaling processes governing platelet adhesive function under conditions of hemodynamic shear stress has been a longstanding goal in platelet research and has been greatly influenced by the development and application of microimaging-based techniques. Advances in the area of epi-fluorescence and confocal-based platelet calcium (Ca(2+)) imaging have facilitated the in vitro and in vivo elucidation of the early signaling events regulating platelet adhesion and activation. These studies have identified distinct Ca(2+) signaling mechanisms that serve to dynamically regulate activation of the major platelet integrin α(IIb)β(3) and associated adhesion and aggregation processes under flow. This chapter describes in detail a ratiometric calcium imaging protocol and associated troubleshooting procedures developed in our laboratory to examine live platelet Ca(2+) signaling dynamics. This technique provides a method for high-resolution imaging of the Ca(2+) dynamics underpinning platelet adhesion and thrombus formation under conditions of pathophysiological shear stress.
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28
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Corum LE, Eichinger CD, Hsiao TW, Hlady V. Using microcontact printing of fibrinogen to control surface-induced platelet adhesion and activation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:8316-22. [PMID: 21657213 PMCID: PMC3261074 DOI: 10.1021/la201064d] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The ability to promote or inhibit specific platelet-surface interactions in well-controlled environments is crucial to studying fundamental adhesion and activation mechanisms. Here, microcontact printing was used to immobilize human fibrinogen covalently in the form of randomly placed, micrometer-sized islands at an overall surface coverage of 20, 50, or 85%. The nonprinted background region was blocked with covalently immobilized human albumin. Platelet adhesion and morphology on each substrate were assessed using combined differential interference and fluorescence microscopy. At 20% coverage, most of the fibrinogen surface features were small round islands, and platelet adhesion and spreading areas were limited by the position and the size of the islands. Platelet circularity, indicated the morphology was mostly rounded. At 50% coverage, some fibrinogen islands coalesced and platelet adhesion and spreading areas increased. Platelet morphology was controlled by the shape of underlying fibrinogen islands, leading to more irregular spreading. At 85% coverage, the fibrinogen pattern was completely interconnected and both platelet adhesion and the spreading area were significantly higher than at lower coverage. In addition, platelets also spread over the albumin regions, suggesting that after a critical surface density of fibrinogen ligands is reached, platelet spreading is no longer inhibited by albumin. Increasing the overall fibrinogen coverage resulted in higher activation levels defined by key morphological characteristics of the spreading platelet.
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29
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Magwenzi SG, Ajjan RA, Standeven KF, Parapia LA, Naseem KM. Factor XIII supports platelet activation and enhances thrombus formation by matrix proteins under flow conditions. J Thromb Haemost 2011; 9:820-33. [PMID: 21320283 DOI: 10.1111/j.1538-7836.2011.04234.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Activated coagulation factor XIII (FXIIIa) is a transglutaminase that crosslinks fibrin at sites of vascular injury. FXIIIa also associates with blood platelets, although its role in platelet function is unclear and requires clarification. OBJECTIVES To evaluate the ability of FXIIIa to support platelet adhesion and spreading under conditions of physiologic flow, and to identify the underpinning receptors and signaling events. METHODS AND RESULTS Platelet adhesion to immobilized FXIIIa was measured by fluorescence microscopy, and signaling events were characterized by immunoblotting. Immobilized FXIIIa supported platelet adhesion and spreading under static conditions through mechanisms that were dually and differentially dependent on integrins α(IIb)β(3) and α(v)β(3). Platelet adhesion was independent of FXIIIa transglutaminase or protein disulfide isomerase activity. Moreover, adhesion was abolished by antibodies that prevented interaction with FXIIIa, but maintained when potential interactions with fibrinogen were blocked. Platelet adhesion to FXIIIa was reduced significantly by either the specific α(IIb)β(3) antagonist tirofiban or the selective α(v)β(3)-blocking antibody LM609, and abolished when they were used in combination. Importantly, platelet adhesion was preserved under venous and arterial flow conditions in which both integrins played essential roles. In contrast, FXIIIa stimulated the formation of filopodia and lamellipodia in adherent platelets that was mediated exclusively by α(IIb)β(3) and eliminated by the Src-family inhibitor 4-amino-5-(4-methylphenyl-7-(t-butyl)pyrazolo(3,4-d)pyrimidine, indicating a tyrosine kinase-dependent mechanism. Crucially, under conditions of arterial shear, FXIIIa accentuated platelet recruitment by von Willebrand factor and collagen. CONCLUSIONS Our data demonstrate a potential role for FXIIIa in supporting platelet adhesion at sites of vascular damage, particularly in association with other thrombogenic matrix proteins.
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Affiliation(s)
- S G Magwenzi
- Centre for Cardiovascular and Metabolic Research, Hull York Medical School, University of Hull, Castle Hill Hospital, Castle Road, Cottingham, UK
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30
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Gratacap MP, Guillermet-Guibert J, Martin V, Chicanne G, Tronchère H, Gaits-Iacovoni F, Payrastre B. Regulation and roles of PI3Kβ, a major actor in platelet signaling and functions. ACTA ACUST UNITED AC 2010; 51:106-16. [PMID: 21035500 DOI: 10.1016/j.advenzreg.2010.09.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 09/06/2010] [Indexed: 01/12/2023]
Abstract
Phosphoinositide 3-kinases (PI3Ks) are important signaling enzymes involved in the regulation of a number of critical cell functions. Significant progress has been made during the last few years in defining the implication of individual PI3K isoforms. The role of the class IA PI3Kβ in different cell types has only been recently uncovered by the use of isoform-selective inhibitors and the development of mouse models harboring p110β catalytic subunit knock-out or germline knock-in of a kinase-dead allele of p110β. Although it is classically admitted that class IA PI3Ks are activated by receptor tyrosine kinases through recruitment of the regulatory subunits to specific tyrosine phosphorylated motifs via their SH2 domains, PI3Kβ is activated downstream of G protein-coupled receptors, and by co-operation between heterotrimeric G proteins and tyrosine kinases. PI3Kβ has been extensively studied in platelets where it appears to play an important role downstream of ITAM signaling, G protein-coupled receptors and aIIbβ3 integrin. Accordingly, mouse exhibiting p110β inactivation selectively in megakaryocyte/platelets are resistant to thromboembolism induced by carotid injury. The present review summarizes recent data concerning the mechanisms of PI3Kβ regulation and the roles of this PI3K isoform in blood platelet functions and other cell types.
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Affiliation(s)
- Marie-Pierre Gratacap
- Inserm, U563, Université Toulouse III, Centre de Physiopathologie de Toulouse Purpan, CHU-Purpan, Toulouse, France
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Deletion of the p110β isoform of phosphoinositide 3-kinase in platelets reveals its central role in Akt activation and thrombus formation in vitro and in vivo. Blood 2010; 115:2008-13. [DOI: 10.1182/blood-2009-04-217224] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Abstract
During platelet activation, phosphoinositide 3-kinases (PI3Ks) produce lipid second messengers participating in the regulation of functional responses. Here, we generated a megakaryocyte-restricted p110β null mouse model and demonstrated a critical role of PI3Kβ in platelet activation via an immunoreceptor tyrosine-based activation motif, the glyco-protein VI-Fc receptor γ-chain complex, and its contribution in response to G-protein–coupled receptors. Interestingly, the production of phosphatidylinositol 3,4,5-trisphosphate and the activation of protein kinase B/Akt were strongly inhibited in p110β null platelets stimulated either via immunoreceptor tyrosine-based activation motif or G-protein–coupled receptors. Functional studies showed an important delay in fibrin clot retraction and an almost complete inability of these platelets to adhere onto fibrinogen under flow condition, suggesting that PI3Kβ is also acting downstream of αIIbβ3. In vivo studies showed that these mice have a normal bleeding time and are not protected from acute pulmonary thromboembolism but are resistant to thrombosis after FeCl3 injury of the carotid, suggesting that PI3Kβ is a potential target for antithrombotic drugs.
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32
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Group IVA cytosolic phospholipase A2 (cPLA2alpha) and integrin alphaIIbbeta3 reinforce each other's functions during alphaIIbbeta3 signaling in platelets. Blood 2008; 113:447-57. [PMID: 18840708 DOI: 10.1182/blood-2008-06-162032] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Group IVA cytosolic phospholipase A(2) (cPLA(2)alpha) catalyzes release of arachidonic acid from glycerophospholipids, leading to thromboxane A(2) (TxA(2)) production. Some platelet agonists stimulate cPLA(2)alpha, but others require fibrinogen binding to alphaIIbbeta3 to elicit TxA(2). Therefore, relationships between cPLA(2)alpha and alphaIIbbeta3 were examined. cPLA(2)alpha and a cPLA(2)alpha binding partner, vimentin, coimmunoprecipitated with alphaIIbbeta3 from platelets, independent of fibrinogen binding. Studies with purified proteins and with recombinant proteins expressed in CHO cells determined that the interaction between cPLA(2)alpha and alphaIIbbeta3 was indirect and was dependent on the alphaIIb and beta3 cytoplasmic tails. Fibrinogen binding to alphaIIbbeta3 caused an increase in integrin-associated cPLA(2)alpha activity in normal platelets, but not in cPLA(2)alpha-deficient mouse platelets or in human platelets treated with pyrrophenone, a cPLA(2)alpha inhibitor. cPLA(2)alpha activation downstream of alphaIIbbeta3 had functional consequences for platelets in that it was required for fibrinogen-dependent recruitment of activated protein kinase Cbeta to the alphaIIbbeta3 complex and for platelet spreading. Thus, cPLA(2)alpha and alphaIIbbeta3 interact to reinforce each other's functions during alphaIIbbeta3 signaling. This provides a plausible explanation for the role of alphaIIbbeta3 in TxA(2) formation and in the defective hemostatic function of mouse or human platelets deficient in cPLA(2)alpha.
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33
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Endothelium–platelet interactions in inflammatory lung disease. Vascul Pharmacol 2008; 49:141-50. [DOI: 10.1016/j.vph.2008.06.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 04/21/2008] [Accepted: 06/13/2008] [Indexed: 01/15/2023]
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34
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Gutierrez E, Petrich BG, Shattil SJ, Ginsberg MH, Groisman A, Kasirer-Friede A. Microfluidic devices for studies of shear-dependent platelet adhesion. LAB ON A CHIP 2008; 8:1486-95. [PMID: 18818803 PMCID: PMC2683765 DOI: 10.1039/b804795b] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Adhesion of platelets to blood vessel walls is a shear stress dependent process that promotes arrest of bleeding and is mediated by the interaction of receptors expressed on platelets with various extracellular matrix (ECM) proteins that may become exposed upon vascular injury. Studies of dynamic platelet adhesion to ECM-coated substrates in conventional flow chambers require substantial fluid volumes and are difficult to perform with blood samples from a single laboratory mouse. Here we report dynamic platelet adhesion assays in two new microfluidic devices made of PDMS. Small cross-sections of the flow chambers in the devices reduce the blood volume requirements to <100 microl per assay, making the assays compatible with samples of whole blood obtained from a single mouse. One device has an array of 8 flow chambers with shear stress varying by a factor of 1.93 between adjacent chambers, covering a 100-fold range from low venous to arterial. The other device allows simultaneous high-resolution fluorescence imaging of dynamic adhesion of platelets from two different blood samples. Adhesion of platelets in the devices to three common ECM substrate coatings was verified to conform with published results. The devices were subsequently used to study the roles of extracellular and intracellular domains of integrin alphaIIbbeta3, a platelet receptor that is a central mediator of platelet aggregation and thrombus formation. The study involved wild-type mice and two genetically modified mouse strains and showed that the absence of the integrin impaired adhesion at all shear stresses, whereas a mutation in its intracellular domain reduced the adhesion only at moderate and high stresses. Because of small sample volumes required, the devices could be employed in research with genetically-modified model organisms and for adhesion tests in clinical settings with blood from neonates.
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Affiliation(s)
- Edgar Gutierrez
- Department of Physics, University of California San Diego, La Jolla, CA
| | - Brian G. Petrich
- Department of Medicine, University of California San Diego, La Jolla, CA
| | - Sanford J. Shattil
- Department of Medicine, University of California San Diego, La Jolla, CA
| | - Mark H. Ginsberg
- Department of Medicine, University of California San Diego, La Jolla, CA
| | - Alex Groisman
- Department of Physics, University of California San Diego, La Jolla, CA
| | - Ana Kasirer-Friede
- Department of Medicine, University of California San Diego, La Jolla, CA
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35
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Identification of FcgammaRIIa as the ITAM-bearing receptor mediating alphaIIbbeta3 outside-in integrin signaling in human platelets. Blood 2008; 112:2780-6. [PMID: 18641368 DOI: 10.1182/blood-2008-02-142125] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Immunoreceptor tyrosine-based activation motif (ITAM)-containing proteins have recently been demonstrated in macrophages and neutrophils to be required for cell surface integrins to transmit activation signals into the cell. To identify ITAM-bearing proteins that mediate signaling via the platelet-specific integrin alphaIIbbeta3, fibrinogen binding was induced by (1) allowing platelets to spread directly on immobilized fibrinogen, or (2) activating the PAR1 thrombin receptor on platelets in suspension. Both initiated strong, ligand binding-dependent tyrosine phosphorylation of the ITAM-bearing platelet Fc receptor, FcgammaRIIa, as well as downstream phosphorylation of the protein tyrosine kinase Syk and activation of phospholipase Cgamma2 (PLCgamma2). Addition of Fab fragments of an FcgammaRIIa-specific monoclonal antibody strongly inhibited platelet spreading on immobilized fibrinogen, as well as downstream tyrosine phosphorylation of FcgammaRIIa, Syk, and PLCgamma2, and platelets from a patient whose platelets express reduced levels of FcgammaRIIa exhibited markedly reduced spreading on immobilized fibrinogen. Finally, fibrinogen binding-induced FcgammaRIIa phosphorylation did not occur in human platelets expressing a truncated beta3 cytoplasmic domain. Taken together, these data suggest that ligand binding to platelet alphaIIbbeta3 induces integrin cytoplasmic domain-dependent phosphorylation of FcgammaRIIa, which then enlists selected components of the immunoreceptor signaling cascade to transmit amplification signals into the cell.
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Barrett NE, Holbrook L, Jones S, Kaiser WJ, Moraes LA, Rana R, Sage T, Stanley RG, Tucker KL, Wright B, Gibbins JM. Future innovations in anti-platelet therapies. Br J Pharmacol 2008; 154:918-39. [PMID: 18587441 PMCID: PMC2451055 DOI: 10.1038/bjp.2008.151] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Revised: 03/31/2008] [Accepted: 03/31/2008] [Indexed: 12/15/2022] Open
Abstract
Platelets have long been recognized to be of central importance in haemostasis, but their participation in pathological conditions such as thrombosis, atherosclerosis and inflammation is now also well established. The platelet has therefore become a key target in therapies to combat cardiovascular disease. Anti-platelet therapies are used widely, but current approaches lack efficacy in a proportion of patients, and are associated with side effects including problem bleeding. In the last decade, substantial progress has been made in understanding the regulation of platelet function, including the characterization of new ligands, platelet-specific receptors and cell signalling pathways. It is anticipated this progress will impact positively on the future innovations towards more effective and safer anti-platelet agents. In this review, the mechanisms of platelet regulation and current anti-platelet therapies are introduced, and strong, and some more speculative, potential candidate target molecules for future anti-platelet drug development are discussed.
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Affiliation(s)
- N E Barrett
- School of Biological Sciences, University of Reading, Whiteknights, Reading Berkshire, UK
| | - L Holbrook
- School of Biological Sciences, University of Reading, Whiteknights, Reading Berkshire, UK
| | - S Jones
- School of Biological Sciences, University of Reading, Whiteknights, Reading Berkshire, UK
| | - W J Kaiser
- School of Biological Sciences, University of Reading, Whiteknights, Reading Berkshire, UK
| | - L A Moraes
- School of Biological Sciences, University of Reading, Whiteknights, Reading Berkshire, UK
| | - R Rana
- School of Biological Sciences, University of Reading, Whiteknights, Reading Berkshire, UK
| | - T Sage
- School of Biological Sciences, University of Reading, Whiteknights, Reading Berkshire, UK
| | - R G Stanley
- School of Biological Sciences, University of Reading, Whiteknights, Reading Berkshire, UK
| | - K L Tucker
- School of Biological Sciences, University of Reading, Whiteknights, Reading Berkshire, UK
| | - B Wright
- School of Biological Sciences, University of Reading, Whiteknights, Reading Berkshire, UK
| | - J M Gibbins
- School of Biological Sciences, University of Reading, Whiteknights, Reading Berkshire, UK
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Arderiu G, Pérez-Pujol S, Escolar G, White JG, Díaz-Ricart M. External calcium facilitates signalling, contractile and secretory mechanisms induced after activation of platelets by collagen. Platelets 2008; 19:172-81. [PMID: 18432518 DOI: 10.1080/09537100701832140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Platelet activation leads to the initiation of intracellular signalling processes, many of which are triggered by Ca2+. We have studied the involvement of exogenous Ca2+ in platelet response to collagen activation. Platelet suspensions were prepared with and without adding external calcium in the suspension buffers. Activation with collagen (Col-I) was carried out, before and after incubation with cytochalasin B (Cyt-B) to block the actin assembly and the cytoskeletal reorganization. We evaluated changes in (i) tyrosine phosphorylation of proteins, in platelet lysates and associated with the cytoskeletal fraction, (ii) the association of contractile proteins to the cytoskeleton, (iii) expression of intraplatelet substances at the surface, and (iv) cytosolic Ca2+ levels ([Ca2+]i). Ultrastructural evaluation of platelets by electron microscopy was also performed. Platelet activation by Col-I in the absence of added Ca2+ was followed by mild association of actin and other contractile proteins, low phosphorylation of proteins at tyrosine residues, lack of expression of intraplatelet substances at the membrane, and absence of aggregation. In the presence of millimolar Ca2+, Col-I induced intense actin filament formation with association of contractile proteins with the cytoskeleton, resulting in profound morphological changes. Under these conditions, Col-I induced signalling through tyrosine phosphorylation, with increases in the [Ca2+]i, release of intragranule content and aggregation. Inhibiting actin polymerization with Cyt-B prevented all these events. Our data indicates that platelet activation by collagen requires external Ca2+. Studies with Cyt-B indicate that assembly of new actin and cytoskeleton-mediated contraction, both dependent on exogenous Ca2+, are key events for platelet activation by collagen. In addition, our results confirm that entrance of exogenous Ca2+ depends on a functional cytoskeleton.
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Affiliation(s)
- Gemma Arderiu
- Servei d'Hemoteràpia-Hemostàsia, Hospital Clínic, IDIBAPS, Universitat de Barcelona, Villarroel, 170, 08036 Barcelona, Spain
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38
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Karim ZA, Choi W, Whiteheart SW. Primary platelet signaling cascades and integrin-mediated signaling control ADP-ribosylation factor (Arf) 6-GTP levels during platelet activation and aggregation. J Biol Chem 2008; 283:11995-2003. [PMID: 18326492 DOI: 10.1074/jbc.m800146200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Previous studies showed that ADP-ribosylation factor 6 (Arf6) is important for platelet function; however, little is known about which signaling events regulate this small GTP-binding protein. Arf6-GTP was monitored in platelets stimulated with a number of agonists (TRAP, thrombin, convulxin, collagen, PMA, thapsigargin, or A23187) and all led to a time-dependent decrease in Arf6-GTP. ADP and U46619 were without effect. Using inhibitors, it was shown that the decrease of Arf6-GTP is a direct consequence of known signaling cascades. Upon stimulation via PAR receptors, Arf6-GTP loss could be blocked by treatment with U-73122, BAPTA/AM, Ro-31-8220, or Gö6976, indicating requirements for phospholipase C, calcium, and protein kinase C (PKC) alpha/beta, respectively. The Arf6-GTP decrease in convulxin-stimulated platelets showed similar requirements and was also sensitive to piceatannol, wortmannin, and LY294002, indicating additional requirements for Syk and phosphatidylinositol 3-kinase. The convulxin-induced decrease was sensitive to both PKCalpha/beta and delta inhibitors. Outside-in signaling, potentially via integrin engagement, caused a second wave of signaling that affected Arf6. Inclusion of RGDS peptides or EGTA, during activation, led to a biphasic response; Arf6-GTP levels partially recovered upon continued incubation. A similar response was seen in beta3 integrin-null platelets. These data show that Arf6-GTP decreases in response to known signaling pathways associated with PAR and GPVI. They further reveal a second, aggregation-dependent, process that dampens Arf6-GTP recovery. This study demonstrates that the nucleotide state of Arf6 in platelets is regulated during the initial phases of activation and during the later stages of aggregation.
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Affiliation(s)
- Zubair A Karim
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40536-0509, USA
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39
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Touat Z, Lepage L, Ollivier V, Nataf P, Hvass U, Labreuche J, Jandrot-Perrus M, Michel JB, Jondeau G. Dilation-dependent activation of platelets and prothrombin in human thoracic ascending aortic aneurysm. Arterioscler Thromb Vasc Biol 2008; 28:940-6. [PMID: 18292393 DOI: 10.1161/atvbaha.107.158576] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate whether thoracic ascending aortic aneurysm (TAAA) induces platelet activation as mural thrombus participates in aortic dilatation in abdominal aortic aneurysm and TAAA are associated with rheological factors favoring coagulation activation. METHODS AND RESULTS We studied the relation between coagulation activation and aortic diameter in Marfan patients (MFS) with various aortic diameters (n=52). We then studied patients presenting large aneurysms associated with bicuspid aortic valve (BAV) and degenerative form. Lastly, we used immunochemistry and biochemistry to investigate prothrombin/thrombin retention within the aortic wall. Microparticles, sGPV, tissue factor, and TAT complexes were increased in plasma from MFS with large aneurysms (>or=45 mm) compared to MFS with limited aortic dilatation (<45 mm). Similar elevations were observed in all patients with large aortic aneurysms, regardless of the etiology, the site of maximal aortic dilation, associated valvulopathy, risk factors, or treatments. P-selectin and platelet-bound fibrinogen were also increased, demonstrating platelet activation in large aneurysms. Significant increase in sCD146 plasma concentration suggested alteration of endothelium. CONCLUSIONS Platelet activation occurs in patients with large aneurysms of the ascending aorta, is dependent on aortic dilation, and is associated with thrombin generation, part of which appears to be retained in mucoid degeneration areas.
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Affiliation(s)
- Ziad Touat
- INSERM, U698, University Paris 7, Paris, France
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40
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Sato H, Suzuki-Inoue K, Inoue O, Ozaki Y. Regulation of adaptor protein GIT1 in platelets, leading to the interaction between GIT1 and integrin alpha(IIb)beta3. Biochem Biophys Res Commun 2008; 368:157-61. [PMID: 18211801 DOI: 10.1016/j.bbrc.2008.01.064] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 01/16/2008] [Indexed: 12/25/2022]
Abstract
GIT1 is an adaptor protein, which links signaling proteins to focal adhesion, thereby regulating cytoskeletal reorganization. Platelets undergo dynamic cytoskeletal reorganization during platelet activation, for which a large number of adaptor proteins are required. However, there has been no report of GIT1 in platelets. We found that GIT1 was abundantly expressed in platelets and underwent tyrosine phosphorylation downstream of integrin alpha(IIb)beta(3), which was inhibited by the Src kinase inhibitor PP2. Furthermore, GIT1 constitutively associated with betaPIX, a guanine nucleotide exchange factor (GEF) for Rac. The GIT1/betaPIX complex associated with alpha(IIb)beta(3), concomitantly with GIT1 tyrosine phosphorylation. Moreover, both GIT1 and alpha(IIb)beta(3) rapidly translocated to the cytoskeletal fraction during platelet aggregation, which was not observed in the absence of aggregation. These results suggest that tyrosine phosphorylation of GIT1 by Src kinases may regulate cytoskeletal reorganization downstream of alpha(IIb)beta(3) by bringing the Rac GEF betaPIX to the vicinity of the integrin.
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Affiliation(s)
- Hitomi Sato
- Department of Clinical and Laboratory Medicine, Faculty of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
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41
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van der Meijden PEJ, Schoenwaelder SM, Feijge MAH, Cosemans JMEM, Munnix ICA, Wetzker R, Heller R, Jackson SP, Heemskerk JWM. Dual P2Y12 receptor signaling in thrombin-stimulated platelets - involvement of phosphoinositide 3-kinase β but not γ isoform in Ca2+ mobilization and procoagulant activity. FEBS J 2007; 275:371-85. [DOI: 10.1111/j.1742-4658.2007.06207.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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42
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Abstract
Stable platelet adhesion to extracellular matrices and the formation of a hemostatic or pathological thrombus are dependent on integrin alphaIIbbeta3, also known as GPIIb-IIIa. However, maximal platelet responses to vascular injury may involve the participation of other integrins expressed in platelets (alphaVbeta3, alpha2beta1, alpha5beta1, and alpha6beta1). Platelet membrane 'immunoreceptors' contain at least one subunit with an extracellular immunoglobulin superfamily domain and/or an intracellular stimulatory immunoreceptor tyrosine-based activation motif (ITAM) or immunoreceptor tyrosine-based inhibitory motif (ITIM). Platelet ITAM receptors, such as FcgammaRIIA and the GPVI-FcRgamma complex, promote activation of integrins, while ITIM receptors, such as platelet-endothelial cell adhesion molecule-1, may promote their inhibition. This review summarizes the structure and function of platelet integrins and immunoreceptors, the emerging functional relationships between these receptor classes, and the consequences of their interaction for platelet function in hemostasis and thrombosis.
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Affiliation(s)
- Ana Kasirer-Friede
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0726, USA.
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43
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Choi JH, Yang YR, Lee SK, Kim IS, Ha SH, Kim EK, Bae YS, Ryu SH, Suh PG. Phospholipase C-gamma1 potentiates integrin-dependent cell spreading and migration through Pyk2/paxillin activation. Cell Signal 2007; 19:1784-96. [PMID: 17531443 DOI: 10.1016/j.cellsig.2007.04.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 03/29/2007] [Accepted: 04/05/2007] [Indexed: 11/25/2022]
Abstract
Phospholipase C-gamma1 (PLC-gamma1), which generates two second messengers, namely, inositol-1, 4, 5-trisphosphate and diacylglycerol, is implicated in growth factor-mediated chemotaxis. However, the exact role of PLC-gamma1 in integrin-mediated cell adhesion and migration remains poorly understood. In this study, we demonstrate that PLC-gamma1 is required for actin cytoskeletal organization and cell motility through the regulation of Pyk2 and paxillin activation. After fibronectin stimulation, PLC-gamma1 directly interacted with the cytoplasmic tail of integrin beta1. In PLC-gamma1-silenced cells, integrin-induced Pyk2 and paxillin phosphorylation were significantly reduced and PLC-gamma1 potentiated the integrin-induced Pyk2/paxillin activation in its enzymatic activity-dependent manner. In addition, specific knock-down of PLC-gamma1 resulted in a failure to form focal adhesions dependent on fibronectin stimulation, which appeared to be caused by the suppression of Pyk2 and paxillin phosphorylation. Interestingly, PLC-gamma1 potentiated the activations of Rac, thus integrin-induced lamellipodia formation was up-regulated. Consequently, the strength of cell-substratum interaction and cell motility were profoundly up-regulated by PLC-gamma1. Taken together, these results suggest that PLC-gamma1 is a key player in integrin-mediated cell spreading and motility achieved by the activation of Pyk2/paxillin/Rac signaling.
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Affiliation(s)
- Jang Hyun Choi
- Department of Life Science, Pohang University of Science and Technology, Pohang, Kyungbuk, 790-784, Republic of Korea
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Jirouskova M, Shet AS, Johnson GJ. A guide to murine platelet structure, function, assays, and genetic alterations. J Thromb Haemost 2007; 5:661-9. [PMID: 17403200 DOI: 10.1111/j.1538-7836.2007.02407.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Platelets play an important role in hemostasis, thrombosis and several other biological processes. The adaptability of mice to genetic manipulation and their genetic similarity to humans has resulted in a plethora of murine models to study platelet function. Although murine platelets differ from human platelets with regard to size, number and structure, functionally they are very similar. Thus, studies which employed these model systems have greatly improved our current understanding of the contribution of platelets to hemostasis and thrombosis. This review presents general recommendations with respect to collection, isolation and processing of murine platelets. It also describes the assays currently available to study platelet function and critically assesses their utility. The extensive literature on the effects of genetic alterations on murine platelet function is considered in detail. This review is intended to provide a convenient source of reference for platelet investigators.
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Affiliation(s)
- M Jirouskova
- Laboratory of Blood and Vascular Biology, Rockefeller University, NY, USA
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45
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Jirousková M, Jaiswal JK, Coller BS. Ligand density dramatically affects integrin alpha IIb beta 3-mediated platelet signaling and spreading. Blood 2007; 109:5260-9. [PMID: 17332246 PMCID: PMC1890822 DOI: 10.1182/blood-2006-10-054015] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The impact of ligand density on integrin-mediated cell adhesion and outside-in signaling is not well understood. Using total internal reflection fluorescent microscopy, conformation-specific antibodies, and Ca(2+) flux measurements, we found that the surface density of fibrinogen affects alpha II b beta 3-mediated platelet signaling, adhesion, and spreading. Adhesion to fibrinogen immobilized at low density leads to rapid increases in cytosolic Ca(2+) and sequential formation of filopodia and lamellipodia. In contrast, adhesion to high-density fibrinogen results in transient or no increases in Ca(2+) and simultaneous formation of filopodia and lamellipodia. alpha II b beta 3 receptors at the basal surface of platelets engage fibrinogen in a ringlike pattern at the cell edges under both conditions. This engagement is, however, more dynamic and easily reversed on high-density fibrinogen. Src and Rac activity and actin polymerization are important for adhesion to low-density fibrinogen, whereas PKC/PI3 kinases contribute to platelet spreading on high-density fibrinogen. We conclude that 2 fundamentally different signaling mechanisms can be initiated by a single integrin receptor interacting with the same ligand when it is immobilized at different densities.
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Affiliation(s)
- Markéta Jirousková
- Laboratory of Blood and Vascular Biology, Rockefeller University, New York, NY 10021, USA.
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46
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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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Hughan SC, Watson SP. Differential regulation of adapter proteins Dok2 and Dok1 in platelets, leading to an association of Dok2 with integrin alphaIIbbeta3. J Thromb Haemost 2007; 5:387-94. [PMID: 17092301 DOI: 10.1111/j.1538-7836.2007.02307.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND We previously demonstrated that Dok2 is rapidly phosphorylated on tyrosine residues in platelets in response to thrombin, the immunoreceptor tyrosine-based activation motif-coupled collagen receptor glycoprotein (GP) VI, and by integrin alphaIIbbeta3. OBJECTIVES AND METHODS In this study we further delineate the regulation of phosphorylation of Dok2 and compare this to the related adapter Dok1. RESULTS We demonstrate expression of Dok1 in platelets and the unexpected observation that the adapter protein undergoes tyrosine phosphorylation in response to thrombin but not to GPVI or integrin alphaIIbbeta3. Furthermore, Dok1 phosphorylation is transient, peaking at 30 s and returning to basal by 5 min, whereas Dok2 phosphorylation is delayed but sustained. Dok2 phosphorylation, but not that of Dok1, is inhibited by Src kinase inhibitors and by chelation of intracellular calcium. Further, phosphorylation of Dok2 by thrombin and integrin alphaIIbbeta3 in mouse platelets is independent of Syk and phospholipase Cgamma2. Additionally, Dok2 coimmunoprecipitates with integrin alphaIIbbeta3 downstream of Src kinases. CONCLUSIONS These results demonstrate differential modes of regulation of Dok1 and Dok2 in platelets. Further, they raise the interesting possibility that Dok2 plays an important role in integrin outside-in signaling through a physical and functional interaction with integrin alphaIIbbeta3.
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Affiliation(s)
- S C Hughan
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, University of Birmingham, Birmingham, UK.
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49
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Thornber K, McCarty OJT, Watson SP, Pears CJ. Distinct but critical roles for integrin ?IIb?3in platelet lamellipodia formation on fibrinogen, collagen-related peptide and thrombin. FEBS J 2006; 273:5032-43. [PMID: 17032352 DOI: 10.1111/j.1742-4658.2006.05500.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Integrins are the major receptor type known to facilitate cell adhesion and lamellipodia formation on extracellular matrix proteins. However, collagen-related peptide and thrombin have recently been shown to mediate platelet lamellipodia formation when presented as immobilized surfaces. The aims of this study were to establish if there exists a role for the platelet integrin alpha(IIb)beta(3) in this response; and if so, whether signalling from the integrin is required for lamellipodia formation on these surfaces. Real-time analysis was used to compare platelet morphological changes on surfaces of fibrinogen, collagen-related peptide or thrombin in the presence of various pharmacological inhibitors and platelets from 'knockout' mice. We demonstrate that collagen-related peptide and thrombin stimulate distinct patterns of platelet lamellipodia formation and elevation of intracellular Ca(2+) to that induced by the integrin alpha(IIb)beta(3) ligand, fibrinogen. Nevertheless, lamellipodia formation on collagen-related peptide and thrombin is dependent upon engagement of alpha(IIb)beta(3), consistent with release of alpha(IIb)beta(3) ligand(s) from platelet granules. However, the requirement for signalling by the integrin on fibrinogen can be bypassed by the addition of thrombin to the solution. These observations reveal a critical role for alpha(IIb)beta(3) in forming lamellipodia on collagen-related peptide and thrombin which is dependent on its ability to function as an adhesive receptor but not necessarily on its ability to signal. These results suggest that integrins may play an important role in lamellipodia formation triggered by nonintegrin ligands in platelets and possibly in other cell types.
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50
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Suzuki-Inoue K, Hughes CE, Inoue O, Kaneko M, Cuyun-Lira O, Takafuta T, Watson SP, Ozaki Y. Involvement of Src kinases and PLCgamma2 in clot retraction. Thromb Res 2006; 120:251-8. [PMID: 17055557 PMCID: PMC1884692 DOI: 10.1016/j.thromres.2006.09.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Revised: 09/08/2006] [Accepted: 09/12/2006] [Indexed: 11/18/2022]
Abstract
The integrin αIIbβ3 plays a critical role in mediating clot retraction by platelets which is important in vivo in consolidating thrombus formation. Actin–myosin interaction is essential for clot retraction. In the present study, we demonstrate that the structurally distinct Src kinase inhibitors, PP2 and PD173952, significantly reduced the rate of clot retraction, but did not prevent it reaching completion. This effect was accompanied by abolition of αIIbβ3-dependent protein tyrosine phosphorylation, including PLCγ2. A role for PLCγ2 in mediating clot retraction was demonstrated using PLCγ2-deficient murine platelets. Furthermore, platelet adhesion to fibrinogen leads to MLC phosphorylation through a pathway that is inhibited by PP2 and by the PLC inhibitor, U73122. These results demonstrate a partial role for Src kinase-dependent activation of PLCγ2 and MLC phosphorylation in mediating clot retraction downstream of integrin αIIbβ3.
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Affiliation(s)
- Katsue Suzuki-Inoue
- Department of Clinical and Laboratory Medicine, Faculty of Medicine, Yamanashi University, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan.
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