1
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Grichine A, Jacob S, Eckly A, Villaret J, Joubert C, Appaix F, Pezet M, Ribba AS, Denarier E, Mazzega J, Rinckel JY, Lafanechère L, Elena-Herrmann B, Rowley JW, Sadoul K. The fate of mitochondria during platelet activation. Blood Adv 2023; 7:6290-6302. [PMID: 37624769 PMCID: PMC10589785 DOI: 10.1182/bloodadvances.2023010423] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
Blood platelets undergo several successive motor-driven reorganizations of the cytoskeleton when they are recruited to an injured part of a vessel. These reorganizations take place during the platelet activation phase, the spreading process on the injured vessel or between fibrin fibers of the forming clot, and during clot retraction. All these steps require a lot of energy, especially the retraction of the clot when platelets develop strong forces similar to those of muscle cells. Platelets can produce energy through glycolysis and mitochondrial respiration. However, although resting platelets have only 5 to 8 individual mitochondria, they produce adenosine triphosphate predominantly via oxidative phosphorylation. Activated, spread platelets show an increase in size compared with resting platelets, and the question arises as to where the few mitochondria are located in these larger platelets. Using expansion microscopy, we show that the number of mitochondria per platelet is increased in spread platelets. Live imaging and focused ion beam-scanning electron microscopy suggest that a mitochondrial fission event takes place during platelet activation. Fission is Drp1 dependent because Drp1-deficient platelets have fused mitochondria. In nucleated cells, mitochondrial fission is associated with a shift to a glycolytic phenotype, and using clot retraction assays, we show that platelets have a more glycolytic energy production during clot retraction and that Drp1-deficient platelets show a defect in clot retraction.
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Affiliation(s)
- Alexei Grichine
- INSERM U1209, Centre National de la Recherche Scientifique Unité Mixed de Recherche 5309, Institute for Advanced Biosciences, University Grenoble Alpes, Grenoble, France
| | - Shancy Jacob
- Molecular Medicine Program, University of Utah, Salt Lake City, UT
| | - Anita Eckly
- INSERM, EFS Grand Est, Biologie et Pharmacologie des Plaquettes Sanguines Unité Mixed de Recherche-S 1255, Fédération de Médecine Translationnelle de Strasbourg, University of Strasbourg, Strasbourg, France
| | - Joran Villaret
- INSERM U1209, Centre National de la Recherche Scientifique Unité Mixed de Recherche 5309, Institute for Advanced Biosciences, University Grenoble Alpes, Grenoble, France
| | - Clotilde Joubert
- INSERM U1209, Centre National de la Recherche Scientifique Unité Mixed de Recherche 5309, Institute for Advanced Biosciences, University Grenoble Alpes, Grenoble, France
| | - Florence Appaix
- INSERM U1209, Centre National de la Recherche Scientifique Unité Mixed de Recherche 5309, Institute for Advanced Biosciences, University Grenoble Alpes, Grenoble, France
| | - Mylène Pezet
- INSERM U1209, Centre National de la Recherche Scientifique Unité Mixed de Recherche 5309, Institute for Advanced Biosciences, University Grenoble Alpes, Grenoble, France
| | - Anne-Sophie Ribba
- INSERM U1209, Centre National de la Recherche Scientifique Unité Mixed de Recherche 5309, Institute for Advanced Biosciences, University Grenoble Alpes, Grenoble, France
| | - Eric Denarier
- INSERM U1216, Commissariat à l'Energie Atomique, Grenoble Institute of Neuroscience, University Grenoble Alpes, Grenoble, France
| | - Jacques Mazzega
- INSERM U1209, Centre National de la Recherche Scientifique Unité Mixed de Recherche 5309, Institute for Advanced Biosciences, University Grenoble Alpes, Grenoble, France
| | - Jean-Yves Rinckel
- INSERM, EFS Grand Est, Biologie et Pharmacologie des Plaquettes Sanguines Unité Mixed de Recherche-S 1255, Fédération de Médecine Translationnelle de Strasbourg, University of Strasbourg, Strasbourg, France
| | - Laurence Lafanechère
- INSERM U1209, Centre National de la Recherche Scientifique Unité Mixed de Recherche 5309, Institute for Advanced Biosciences, University Grenoble Alpes, Grenoble, France
| | - Bénédicte Elena-Herrmann
- INSERM U1209, Centre National de la Recherche Scientifique Unité Mixed de Recherche 5309, Institute for Advanced Biosciences, University Grenoble Alpes, Grenoble, France
| | - Jesse W. Rowley
- Molecular Medicine Program, University of Utah, Salt Lake City, UT
| | - Karin Sadoul
- INSERM U1209, Centre National de la Recherche Scientifique Unité Mixed de Recherche 5309, Institute for Advanced Biosciences, University Grenoble Alpes, Grenoble, France
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2
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Mollica MY, Beussman KM, Kandasamy A, Rodríguez LM, Morales FR, Chen J, Manohar K, Del Álamo JC, López JA, Thomas WE, Sniadecki NJ. Distinct platelet F-actin patterns and traction forces on von Willebrand factor versus fibrinogen. Biophys J 2023; 122:3738-3748. [PMID: 37434354 PMCID: PMC10541491 DOI: 10.1016/j.bpj.2023.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/27/2023] [Accepted: 07/07/2023] [Indexed: 07/13/2023] Open
Abstract
Upon vascular injury, platelets form a hemostatic plug by binding to the subendothelium and to each other. Platelet-to-matrix binding is initially mediated by von Willebrand factor (VWF) and platelet-to-platelet binding is mediated mainly by fibrinogen and VWF. After binding, the actin cytoskeleton of a platelet drives its contraction, generating traction forces that are important to the cessation of bleeding. Our understanding of the relationship between adhesive environment, F-actin morphology, and traction forces is limited. Here, we examined F-actin morphology of platelets attached to surfaces coated with fibrinogen and VWF. We identified distinct F-actin patterns induced by these protein coatings and found that these patterns were identifiable into three classifications via machine learning: solid, nodular, and hollow. We observed that traction forces for platelets were significantly higher on VWF than on fibrinogen coatings and these forces varied by F-actin pattern. In addition, we analyzed the F-actin orientation in platelets and noted that their filaments were more circumferential when on fibrinogen coatings and having a hollow F-actin pattern, while they were more radial on VWF and having a solid F-actin pattern. Finally, we noted that subcellular localization of traction forces corresponded to protein coating and F-actin pattern: VWF-bound, solid platelets had higher forces at their central region while fibrinogen-bound, hollow platelets had higher forces at their periphery. These distinct F-actin patterns on fibrinogen and VWF and their differences in F-actin orientation, force magnitude, and force localization could have implications in hemostasis, thrombus architecture, and venous versus arterial thrombosis.
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Affiliation(s)
- Molly Y Mollica
- Department of Bioengineering, University of Washington, Seattle, Washington; Division of Hematology, School of Medicine, University of Washington, Seattle, Washington; Bloodworks Research Institute, Seattle, Washington; Department of Mechanical Engineering, University of Maryland, Baltimore County, Baltimore, Maryland.
| | - Kevin M Beussman
- Department of Mechanical Engineering, University of Washington, Seattle, Washington; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington
| | - Adithan Kandasamy
- Department of Mechanical Engineering, University of Washington, Seattle, Washington; Center for Cardiovascular Biology, University of Washington, Seattle, Washington
| | | | | | - Junmei Chen
- Bloodworks Research Institute, Seattle, Washington
| | - Krithika Manohar
- Department of Mechanical Engineering, University of Washington, Seattle, Washington
| | - Juan C Del Álamo
- Department of Mechanical Engineering, University of Washington, Seattle, Washington; Center for Cardiovascular Biology, University of Washington, Seattle, Washington
| | - José A López
- Division of Hematology, School of Medicine, University of Washington, Seattle, Washington; Bloodworks Research Institute, Seattle, Washington
| | - Wendy E Thomas
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Nathan J Sniadecki
- Department of Bioengineering, University of Washington, Seattle, Washington; Department of Mechanical Engineering, University of Washington, Seattle, Washington; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington; Center for Cardiovascular Biology, University of Washington, Seattle, Washington; Resuscitation Engineering Science Unit, University of Washington, Seattle, Washington; Molecular Engineering and Science Institute, University of Washington, Seattle, Washington; Department of Lab Medicine and Pathology, University of Washington, Seattle, Washington.
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3
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Zelená A, Blumberg J, Probst D, Gerasimaitė R, Lukinavičius G, Schwarz US, Köster S. Force generation in human blood platelets by filamentous actomyosin structures. Biophys J 2023; 122:3340-3353. [PMID: 37475214 PMCID: PMC10465724 DOI: 10.1016/j.bpj.2023.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 02/11/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023] Open
Abstract
Blood platelets are central elements of the blood clotting response after wounding. Upon vessel damage, they bind to the surrounding matrix and contract the forming thrombus, thus helping to restore normal blood circulation. The hemostatic function of platelets is directly connected to their mechanics and cytoskeletal organization. The reorganization of the platelet cytoskeleton during spreading occurs within minutes and leads to the formation of contractile actomyosin bundles, but it is not known if there is a direct correlation between the emerging actin structures and the force field that is exerted to the environment. In this study, we combine fluorescence imaging of the actin structures with simultaneous traction force measurements in a time-resolved manner. In addition, we image the final states with superresolution microscopy. We find that both the force fields and the cell shapes have clear geometrical patterns defined by stress fibers. Force generation is localized in a few hotspots, which appear early during spreading, and, in the mature state, anchor stress fibers in focal adhesions. Moreover, we show that, for a gel stiffness in the physiological range, force generation is a very robust mechanism and we observe no systematic dependence on the amount of added thrombin in solution or fibrinogen coverage on the substrate, suggesting that force generation after platelet activation is a threshold phenomenon that ensures reliable thrombus contraction in diverse environments.
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Affiliation(s)
- Anna Zelená
- Institute for X-Ray Physics, University of Göttingen, Göttingen, Germany
| | - Johannes Blumberg
- Institute for Theoretical Physics, University of Heidelberg, Heidelberg, Germany; BioQuant-Center for Quantitative Biology, University of Heidelberg, Heidelberg, Germany
| | - Dimitri Probst
- Institute for Theoretical Physics, University of Heidelberg, Heidelberg, Germany; BioQuant-Center for Quantitative Biology, University of Heidelberg, Heidelberg, Germany
| | - Rūta Gerasimaitė
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | | | - Ulrich S Schwarz
- Institute for Theoretical Physics, University of Heidelberg, Heidelberg, Germany; BioQuant-Center for Quantitative Biology, University of Heidelberg, Heidelberg, Germany.
| | - Sarah Köster
- Institute for X-Ray Physics, University of Göttingen, Göttingen, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.
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4
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Mitchell JL, Little G, Bye AP, Gaspar RS, Unsworth AJ, Kriek N, Sage T, Stainer A, Sangowawa I, Morrow GB, Bastos RN, Shapiro S, Desborough MJ, Curry N, Gibbins JM, Whyte CS, Mutch NJ, Jones CI. Platelet factor XIII-A regulates platelet function and promotes clot retraction and stability. Res Pract Thromb Haemost 2023; 7:100200. [PMID: 37601014 PMCID: PMC10439398 DOI: 10.1016/j.rpth.2023.100200] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 05/16/2023] [Accepted: 05/23/2023] [Indexed: 08/22/2023] Open
Abstract
Background Factor XIII (FXIII) is an important proenzyme in the hemostatic system. The plasma-derived enzyme activated FXIII cross-links fibrin fibers within thrombi to increase their mechanical strength and cross-links fibrin to fibrinolytic inhibitors, specifically α2-antiplasmin, to increase resistance to fibrinolysis. We have previously shown that cellular FXIII (factor XIII-A [FXIII-A]), which is abundant in the platelet cytoplasm, is externalized onto the activated membrane and cross-links extracellular substrates. The contribution of cellular FXIII-A to platelet activation and platelet function has not been extensively studied. Objectives This study aims to identify the role of platelet FXIII-A in platelet function. Methods We used normal healthy platelets with a cell permeable FXIII inhibitor and platelets from FXIII-deficient patients as a FXIII-free platelet model in a range of platelet function and clotting tests. Results Our data demonstrate that platelet FXIII-A enhances fibrinogen binding to the platelet surface upon agonist stimulation and improves the binding of platelets to fibrinogen and aggregation under flow in a whole-blood thrombus formation assay. In the absence of FXIII-A, platelets show reduced sensitivity to agonist stimulation, including decreased P-selectin exposure and fibrinogen binding. We show that FXIII-A is involved in platelet spreading where a lack of FXIII-A reduces the ability of platelets to fully spread on fibrinogen and collagen. Our data demonstrate that platelet FXIII-A is important for clot retraction where clots formed in its absence retracted to a lesser extent. Conclusion Overall, this study shows that platelet FXIII-A functions during thrombus formation by aiding platelet activation and thrombus retraction in addition to its antifibrinolytic roles.
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Affiliation(s)
- Joanne L. Mitchell
- Institute for Cardiovascular Research, University of Birmingham, Birmingham, UK
| | - Gemma Little
- Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | | | - Renato S. Gaspar
- Heart Institute, University of Sao Paulo School of Medicine, Sao Paulo, Brazil
| | - Amanda J. Unsworth
- Department of Life Sciences, Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, UK
| | - Neline Kriek
- Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | - Tanya Sage
- Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | - Alexander Stainer
- Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | - Ibidayo Sangowawa
- Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | - Gael B. Morrow
- Oxford University Hospitals NHS Foundation Trust, Blood Theme Oxford Biomedical Research Centre, Oxford, UK
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | | | - Susan Shapiro
- Oxford University Hospitals NHS Foundation Trust, Blood Theme Oxford Biomedical Research Centre, Oxford, UK
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Michael J.R. Desborough
- Oxford University Hospitals NHS Foundation Trust, Blood Theme Oxford Biomedical Research Centre, Oxford, UK
| | - Nicola Curry
- Oxford University Hospitals NHS Foundation Trust, Blood Theme Oxford Biomedical Research Centre, Oxford, UK
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jonathan M. Gibbins
- Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | - Claire S. Whyte
- Aberdeen Cardiovascular & Diabetes Centre, School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Nicola J. Mutch
- Aberdeen Cardiovascular & Diabetes Centre, School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Christopher I. Jones
- Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
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5
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Pontarollo G, Reinhardt C. The hemorrhage risk of dasatinib therapy. Blood 2023; 141:2917-2918. [PMID: 37318908 DOI: 10.1182/blood.2023020399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023] Open
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6
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Bura A, de Matteis MA, Bender M, Swinkels M, Versluis J, Jansen AJG, Jurak Begonja A. Oculocerebrorenal syndrome of Lowe protein controls cytoskeletal reorganisation during human platelet spreading. Br J Haematol 2023; 200:87-99. [PMID: 36176266 DOI: 10.1111/bjh.18478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 09/05/2022] [Accepted: 09/14/2022] [Indexed: 11/28/2022]
Abstract
Lowe syndrome (LS) is a rare, X-linked disorder characterised by numerous symptoms affecting the brain, the eyes, and the kidneys. It is caused by mutations in the oculocerebrorenal syndrome of Lowe (OCRL) protein, a 5-phosphatase localised in different cellular compartments that dephosphorylates phosphatidylinositol-4,5-bisphosphate into phosphatidylinositol-4-monophosphate. Some patients with LS also have bleeding disorders, with normal to low platelet (PLT) count and impaired PLT function. However, the mechanism of PLT dysfunction in patients with LS is not completely understood. The main function of PLTs is to activate upon vessel wall injury and stop the bleeding by clot formation. PLT activation is accompanied by a shape change that is a result of massive cytoskeletal rearrangements. Here, we show that OCRL-inhibited human PLTs do not fully spread, form mostly filopodia, and accumulate actin nodules. These nodules co-localise with ARP2/3 subunit p34, vinculin, and sorting nexin 9. Furthermore, OCRL-inhibited PLTs have a retained microtubular coil with high levels of acetylated tubulin. Also, myosin light chain phosphorylation is decreased upon OCRL inhibition, without impaired degranulation or integrin activation. Taken together, these results suggest that OCRL contributes to cytoskeletal rearrangements during PLT activation that could explain mild bleeding problems in patients with LS.
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Affiliation(s)
- Ana Bura
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
| | - Maria Antonietta de Matteis
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli, Naples, Italy.,Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Markus Bender
- Institute of Experimental Biomedicine, University Hospital Wuerzburg, Rudolf Virchow Center, Wuerzburg, Germany
| | - Maurice Swinkels
- Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Jurjen Versluis
- Erasmus MC University Medical Center, Rotterdam, the Netherlands
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7
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Trigani KT, DeCortin M, Diamond S. ADP and thromboxane inhibitors both reduce global contraction of clot length, while thromboxane inhibition attenuates internal aggregate contraction. TH OPEN 2022; 6:e135-e143. [PMID: 35707619 PMCID: PMC9192180 DOI: 10.1055/a-1832-9293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 04/14/2022] [Indexed: 11/10/2022] Open
Abstract
Platelet contractility drives clot contraction to enhance clot density and stability. Clot contraction is typically studied under static conditions, with fewer studies of wall-adherent platelet clots formed under flow. We tested the effect of inhibitors of ADP and/or thromboxane A2 (TXA2) signaling on clot contraction. Using an eight-channel microfluidic device, we perfused PPACK-treated whole blood (WB) ± acetylsalicylic acid (ASA), 2-methylthioAMP (2-MeSAMP), and/or MRS-2179 over collagen (100/s) for 7.5 min, then stopped flow to observe contraction for 7.5 minutes. Two automated imaging methods scored fluorescent platelet percent contraction over the no-flow observation period: (1) “global” measurement of clot length and (2) “local” changes in surface area coverage of the numerous platelet aggregates within the clot. Total platelet fluorescence intensity (FI) decreased with concomitant decrease in global aggregate contraction when ASA, 2-MeSAMP, and/or MRS-2179 were present. Total platelet FI and global aggregate contraction were highly correlated (
R2
= 0.87). In contrast, local aggregate contraction was more pronounced than global aggregate contraction across all inhibition conditions. However, ASA significantly reduced local aggregate contraction relative to conditions without TXA2 inhibition. P-selectin display was significantly reduced by ADP and TXA2 inhibition, but there was limited detection of global or local aggregate contraction in P-selectin-positive platelets across all conditions, as expected for densely packed “core” platelets. Our results demonstrate that global aggregate contraction is inhibited by ASA, 2-MeSAMP, and MRS-2179, while ASA more potently inhibited local aggregate contraction. These results help resolve how different platelet antagonists affect global and local clot structure and function.
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Affiliation(s)
- Kevin Timothy Trigani
- Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, United States
| | - Michael DeCortin
- Chemical & Biomolecular Engineering, University of Pennsylvania, Philadelphia, United States
| | - Scott Diamond
- Institute for Medicine and Engineering, U Penn Vagelos Research Laboratories, Philadelphia, United States
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8
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Ngo ATP, Parra-Izquierdo I, Aslan JE, McCarty OJT. Rho GTPase regulation of reactive oxygen species generation and signalling in platelet function and disease. Small GTPases 2021; 12:440-457. [PMID: 33459160 DOI: 10.1080/21541248.2021.1878001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Platelets are master regulators and effectors of haemostasis with increasingly recognized functions as mediators of inflammation and immune responses. The Rho family of GTPase members Rac1, Cdc42 and RhoA are known to be major components of the intracellular signalling network critical to platelet shape change and morphological dynamics, thus playing a major role in platelet spreading, secretion and thrombus formation. Initially linked to the regulation of actomyosin contraction and lamellipodia formation, recent reports have uncovered non-canonical functions of platelet RhoGTPases in the regulation of reactive oxygen species (ROS), where intrinsically generated ROS modulate platelet function and contribute to thrombus formation. Platelet RhoGTPases orchestrate oxidative processes and cytoskeletal rearrangement in an interconnected manner to regulate intracellular signalling networks underlying platelet activity and thrombus formation. Herein we review our current knowledge of the regulation of platelet ROS generation by RhoGTPases and their relationship with platelet cytoskeletal reorganization, activation and function.
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Affiliation(s)
- Anh T P Ngo
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon, USA
| | - Ivan Parra-Izquierdo
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon, USA.,Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Joseph E Aslan
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon, USA.,Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA.,Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon, USA
| | - Owen J T McCarty
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon, USA
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9
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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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10
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A. Matthay Z, Zumwinkle Kornblith L. Platelet Imaging. Platelets 2020. [DOI: 10.5772/intechopen.91736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The knowledge gained through imaging platelets has formed the backbone of our understanding of their biology in health and disease. Early investigators relied on conventional light microscopy with limited resolution and were primarily able to identify the presence and basic morphology of platelets. The advent of high resolution technologies, in particular, electron microscopy, accelerated our understanding of the dynamics of platelet ultrastructure dramatically. Further refinements and improvements in our ability to localize and reliably identify platelet structures have included the use of immune-labeling techniques, correlative-fluorescence light and electron microscopy, and super-resolution microscopies. More recently, the expanded development and application of intravital microscopy in animal models has enhanced our knowledge of platelet functions and thrombus formation in vivo, as these experimental systems most closely replicate native biological environments. Emerging improvements in our ability to characterize platelets at the ultrastructural and organelle levels include the use of platelet cryogenic electron tomography with quantitative, unbiased imaging analysis, and the ability to genetically label platelet features with electron dense markers for analysis by electron microscopy.
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11
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Mayr S, Hauser F, Puthukodan S, Axmann M, Göhring J, Jacak J. Statistical analysis of 3D localisation microscopy images for quantification of membrane protein distributions in a platelet clot model. PLoS Comput Biol 2020; 16:e1007902. [PMID: 32603371 PMCID: PMC7384682 DOI: 10.1371/journal.pcbi.1007902] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 07/27/2020] [Accepted: 04/22/2020] [Indexed: 11/19/2022] Open
Abstract
We present the software platform 2CALM that allows for a comparative analysis of 3D localisation microscopy data representing protein distributions in two biological samples. The in-depth statistical analysis reveals differences between samples at the nanoscopic level using parameters such as cluster-density and -curvature. An automatic classification system combines multiplex and multi-level statistical approaches into one comprehensive parameter for similarity testing of the compared samples. We demonstrated the biological importance of 2CALM, comparing the protein distributions of CD41 and CD62p on activated platelets in a 3D artificial clot. Additionally, using 2CALM, we quantified the impact of the inflammatory cytokine interleukin-1β on platelet activation in clots. The platform is applicable to any other cell type and biological system and can provide new insights into biological and medical applications.
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Affiliation(s)
- Sandra Mayr
- University of Applied Sciences Upper Austria, Linz, Austria
| | - Fabian Hauser
- University of Applied Sciences Upper Austria, Linz, Austria
| | | | - Markus Axmann
- University of Applied Sciences Upper Austria, Linz, Austria
| | - Janett Göhring
- Center for Pathophysiology, Infectiology and Immunology, Institute for Hygiene and Applied Immunology, Medical University of Vienna, Vienna, Austria
| | - Jaroslaw Jacak
- University of Applied Sciences Upper Austria, Linz, Austria
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12
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Green HLH, Zuidscherwoude M, Alenazy F, Smith CW, Bender M, Thomas SG. SMIFH2 inhibition of platelets demonstrates a critical role for formin proteins in platelet cytoskeletal dynamics. J Thromb Haemost 2020; 18:955-967. [PMID: 31930764 PMCID: PMC7186844 DOI: 10.1111/jth.14735] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 01/07/2020] [Indexed: 12/24/2022]
Abstract
BACKGROUND Reorganization of the actin cytoskeleton is required for proper functioning of platelets following activation in response to vascular damage. Formins are a family of proteins that regulate actin polymerization and cytoskeletal organization via a number of domains including the FH2 domain. However, the role of formins in platelet spreading has not been studied in detail. OBJECTIVES Several formin proteins are expressed in platelets so we used an inhibitor of FH2 domains (SMIFH2) to uncover the role of these proteins in platelet spreading and in maintenance of resting platelet shape. METHODS Washed human and mouse platelets were treated with various concentrations of SMIFH2 and the effects on platelet spreading, platelet size, platelet cytoskeletal dynamics, and organization were analyzed using fluorescence and electron microscopy. RESULTS Pretreatment with SMIFH2 completely blocks platelet spreading in both mouse and human platelets through effects on the organization and dynamics of actin and microtubules. However, platelet aggregation and secretion are unaffected. SMIFH2 also caused a decrease in resting platelet size and disrupted the balance of tubulin post-translational modification. CONCLUSIONS These data therefore demonstrated an important role for formin-mediated actin polymerization in platelet spreading and highlighted the importance of formins in cross-talk between the actin and tubulin cytoskeletons.
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Affiliation(s)
- Hannah L. H. Green
- Institute of Cardiovascular SciencesUniversity of BirminghamBirminghamUK
- Present address:
School of Cardiovascular Medicine & SciencesBHF Centre of Research ExcellenceKing's College LondonLondonUK
| | - Malou Zuidscherwoude
- Institute of Cardiovascular SciencesUniversity of BirminghamBirminghamUK
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamMidlandsUK
| | - Fawaz Alenazy
- Institute of Cardiovascular SciencesUniversity of BirminghamBirminghamUK
| | | | - Markus Bender
- Institute of Experimental Biomedicine – Chair IUniversity Hospital and Rudolf Virchow CenterWürzburgGermany
| | - Steven G. Thomas
- Institute of Cardiovascular SciencesUniversity of BirminghamBirminghamUK
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamMidlandsUK
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13
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Riley DRJ, Khalil JS, Naseem KM, Rivero F. Biochemical and immunocytochemical characterization of coronins in platelets. Platelets 2019; 31:913-924. [PMID: 31801396 PMCID: PMC7497283 DOI: 10.1080/09537104.2019.1696457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Rapid reorganization of the actin cytoskeleton in response to receptor-mediated signaling cascades allows platelets to transition from a discoid shape to a flat spread shape upon adhesion to damaged vessel walls. Coronins are conserved regulators of the actin cytoskeleton turnover but they also participate in signaling events. To gain a better picture of their functions in platelets we have undertaken a biochemical and immunocytochemical investigation with a focus on Coro1. We found that class I coronins Coro1, 2 and 3 are abundant in human and mouse platelets whereas little Coro7 can be detected. Coro1 is mainly cytosolic, but a significant amount associates with membranes in an actin-independent manner and does not translocate from or to the membrane fraction upon exposure to thrombin, collagen or prostacyclin. Coro1 rapidly translocates to the Triton insoluble cytoskeleton upon platelet stimulation with thrombin or collagen. Coro1, 2 and 3 show a diffuse cytoplasmic localization with discontinuous accumulation at the cell cortex and actin nodules of human platelets, where all three coronins colocalize. Our data are consistent with a role of coronins as integrators of extracellular signals with actin remodeling and suggests a high extent of functional overlap among class I coronins in platelets.
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Affiliation(s)
- David R J Riley
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull , Hull, UK
| | - Jawad S Khalil
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull , Hull, UK.,School of Physiology, Pharmacology and Neuroscience, Faculty of Life Sciences, University of Bristol , Bristol, UK
| | - Khalid M Naseem
- Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds , Leeds, UK
| | - Francisco Rivero
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull , Hull, UK
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14
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Zarka R, Horev MB, Volberg T, Neubauer S, Kessler H, Spatz JP, Geiger B. Differential Modulation of Platelet Adhesion and Spreading by Adhesive Ligand Density. NANO LETTERS 2019; 19:1418-1427. [PMID: 30649888 PMCID: PMC6437653 DOI: 10.1021/acs.nanolett.8b03513] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 01/08/2019] [Indexed: 05/25/2023]
Abstract
Platelets play a major role in hemostasis and thrombosis, by binding to the underlying extracellular matrix around injured blood vessels, via integrin receptors. In this study, we investigated the effects of adhesive ligand spacing on the stability of platelets' adhesion and the mode of their spreading on extracellular surfaces. Toward this end, we have examined the differential adhesion and spreading of human platelets onto nanogold-patterned surfaces, functionalized with the αIIbβ3 integrin ligand, SN528. Combining light- and scanning electron-microscopy, we found that interaction of platelets with surfaces coated with SN528 at spacing of 30-60 nm induces the extension of filopodia through which the platelets stably attach to the nanopatterned surface and spread on it. Increasing the nanopattern-gold spacing to 80-100 nm resulted in a dramatic reduction (>95%) in the number of adhering platelets. Surprisingly, a further increase in ligand spacing to 120 nm resulted in platelet binding to the surface at substantially larger numbers, yet these platelets remained discoid and were essentially devoid of filopodia and lamellipodia. These results indicate that the stimulation of filopodia extension by adhering platelets, and the consequent spreading on these surfaces depend on different ligand densities. Thus, the extension of filopodia occurs on surfaces with a ligand spacing of 100 nm or less, while the sustainability and growth of these initial adhesions and induction of extensive platelet adhesion and spreading requires lower ligand-to-ligand spacing (≤60 nm). The mechanisms underlying this differential ligand-density sensing by platelets, as well as the unexpected retention of discoid platelets on surfaces with even larger spacing (120 nm) are discussed.
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Affiliation(s)
- Revital Zarka
- Department
of Molecular Cell Biology, The Weizmann
Institute of Science, Rehovot 76100, Israel
| | - Melanie B. Horev
- Department
of Molecular Cell Biology, The Weizmann
Institute of Science, Rehovot 76100, Israel
| | - Tova Volberg
- Department
of Molecular Cell Biology, The Weizmann
Institute of Science, Rehovot 76100, Israel
| | - Stefanie Neubauer
- Institute
for Advanced Study (IAS) and Center of Integrated Protein Science,
Department of Chemistry, Technical University
of Munich, 85747 Garching, Germany
| | - Horst Kessler
- Institute
for Advanced Study (IAS) and Center of Integrated Protein Science,
Department of Chemistry, Technical University
of Munich, 85747 Garching, Germany
| | - Joachim P. Spatz
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
| | - Benjamin Geiger
- Department
of Molecular Cell Biology, The Weizmann
Institute of Science, Rehovot 76100, Israel
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15
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16
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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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17
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The membrane-associated fraction of cyclase associate protein 1 translocates to the cytosol upon platelet stimulation. Sci Rep 2018; 8:10804. [PMID: 30018317 PMCID: PMC6050311 DOI: 10.1038/s41598-018-29151-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/03/2018] [Indexed: 01/09/2023] Open
Abstract
Platelets undergo profound shape changes upon adhesion to damaged blood vessel walls that are mediated by reorganisation of the actin cytoskeleton in response to receptor-mediated signalling cascades. The highly conserved 56 kDa multidomain cyclase associated protein 1 (CAP1) works in concert with cofilin and profilin to modulate actin filament turnover by facilitating cofilin-mediated actin filament severing and depolymerisation and catalysing profilin-mediated regeneration of actin monomers for reutilisation in growing filaments. CAP1 is abundant in platelets but its roles remain unexplored. We report that in suspended platelets CAP1 localises predominantly at the cell cortex whereas in spread platelets it is uniformly distributed in the cytoplasm, with enrichment at the cell cortex and the periphery of actin nodules. Upon subcellular fractionation most CAP1 was found cytosolic but part associated to the membrane fraction in an actin-independent manner. Interestingly, upon stimulation with thrombin a significant proportion of the membrane-associated CAP1 translocates to the cytosol. This relocalisation was prevented by prior treatment with PGI2 or the nitric oxide donor GSNO, or by inhibition of GSK3. Our results place CAP1 at a crossroad of signalling pathways that control platelet activation by contributing to actin remodelling at the cell cortex and actin nodules during platelet spreading.
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18
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Paknikar AK, Eltzner B, Köster S. Direct characterization of cytoskeletal reorganization during blood platelet spreading. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2018; 144:166-176. [PMID: 29843920 DOI: 10.1016/j.pbiomolbio.2018.05.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/15/2018] [Accepted: 05/04/2018] [Indexed: 11/18/2022]
Abstract
Blood platelets are the key cellular players in blood clotting and thus of great biomedical importance. While spreading at the site of injury, they reorganize their cytoskeleton within minutes and assume a flat appearance. As platelets possess no nucleus, many standard methods for visualizing cytoskeletal components by means of fluorescence tags fail. Here we employ silicon-rhodamine actin and tubulin probes for imaging these important proteins in a time-resolved manner. We find two distinct timescales for platelet spread area development and for cytoskeletal reorganization, indicating that although cell spreading is most likely associated with actin polymerization at the cell edges, distinct, stress-fiber-like actin structures within the cell, which may be involved in the generation of contractile forces, form on their own timescale. Following microtubule dynamics allows us to distinguish the role of myosin, microtubules and actin during early spreading.
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Affiliation(s)
- Aishwarya K Paknikar
- Institute for X-Ray Physics, University of Goettingen, Göttingen, 37077, Germany
| | - Benjamin Eltzner
- Institute for Mathematical Stochastics, University of Goettingen, Göttingen, 37077, Germany
| | - Sarah Köster
- Institute for X-Ray Physics, University of Goettingen, Göttingen, 37077, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Germany.
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19
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Atkinson L, Yusuf MZ, Aburima A, Ahmed Y, Thomas SG, Naseem KM, Calaminus SDJ. Reversal of stress fibre formation by Nitric Oxide mediated RhoA inhibition leads to reduction in the height of preformed thrombi. Sci Rep 2018; 8:3032. [PMID: 29445102 PMCID: PMC5813033 DOI: 10.1038/s41598-018-21167-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/24/2018] [Indexed: 01/10/2023] Open
Abstract
Evidence has emerged to suggest that thrombi are dynamic structures with distinct areas of differing platelet activation and inhibition. We hypothesised that Nitric oxide (NO), a platelet inhibitor, can modulate the actin cytoskeleton reversing platelet spreading, and therefore reduce the capability of thrombi to withstand a high shear environment. Our data demonstrates that GSNO, DEANONOate, and a PKG-activating cGMP analogue reversed stress fibre formation and increased actin nodule formation in adherent platelets. This effect is sGC dependent and independent of ADP and thromboxanes. Stress fibre formation is a RhoA dependent process and NO induced RhoA inhibition, however, it did not phosphorylate RhoA at ser188 in spread platelets. Interestingly NO and PGI2 synergise to reverse stress fibre formation at physiologically relevant concentrations. Analysis of high shear conditions indicated that platelets activated on fibrinogen, induced stress fibre formation, which was reversed by GSNO treatment. Furthermore, preformed thrombi on collagen post perfused with GSNO had a 30% reduction in thrombus height in comparison to the control. This study demonstrates that NO can reverse key platelet functions after their initial activation and identifies a novel mechanism for controlling excessive thrombosis.
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Affiliation(s)
- L Atkinson
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull, HU6 7RX, UK
| | - M Z Yusuf
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull, HU6 7RX, UK
| | - A Aburima
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull, HU6 7RX, UK
| | - Y Ahmed
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull, HU6 7RX, UK
| | - S G Thomas
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.,Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, UK
| | - K M Naseem
- Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds, LS2 9JT, UK
| | - S D J Calaminus
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull, HU6 7RX, UK.
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20
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Prostacyclin reverses platelet stress fibre formation causing platelet aggregate instability. Sci Rep 2017; 7:5582. [PMID: 28717253 PMCID: PMC5514131 DOI: 10.1038/s41598-017-05817-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 06/02/2017] [Indexed: 01/10/2023] Open
Abstract
Prostacyclin (PGI2) modulates platelet activation to regulate haemostasis. Evidence has emerged to suggest that thrombi are dynamic structures with distinct areas of differing platelet activation. It was hypothesised that PGI2 could reverse platelet spreading by actin cytoskeletal modulation, leading to reduced capability of platelet aggregates to withstand a high shear environment. Our data demonstrates that post-flow of PGI2 over activated and spread platelets on fibrinogen, identified a significant reduction in platelet surface area under high shear. Exploration of the molecular mechanisms underpinning this effect revealed that PGI2 reversed stress fibre formation in adherent platelets, reduced platelet spreading, whilst simultaneously promoting actin nodule formation. The effects of PGI2 on stress fibres were mimicked by the adenylyl cyclase activator forskolin and prevented by inhibitors of protein kinase A (PKA). Stress fibre formation is a RhoA dependent process and we found that treatment of adherent platelets with PGI2 caused inhibitory phosphorylation of RhoA, reduced RhoA GTP-loading and reversal of myosin light chain phosphorylation. Phospho-RhoA was localised in actin nodules with PKA type II and a number of other phosphorylated PKA substrates. This study demonstrates that PGI2 can reverse key platelet functions after their initial activation and identifies a novel mechanism for controlling thrombosis.
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21
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Thomas SG, Poulter NS, Bem D, Finney B, Machesky LM, Watson SP. The actin binding proteins cortactin and HS1 are dispensable for platelet actin nodule and megakaryocyte podosome formation. Platelets 2017; 28:372-379. [PMID: 27778524 PMCID: PMC5274539 DOI: 10.1080/09537104.2016.1235688] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/06/2016] [Accepted: 08/22/2016] [Indexed: 11/08/2022]
Abstract
A dynamic, properly organised actin cytoskeleton is critical for the production and haemostatic function of platelets. The Wiskott Aldrich Syndrome protein (WASp) and Actin-Related Proteins 2 & 3 Complex (Arp2/3 complex) are critical mediators of actin polymerisation and organisation in many cell types. In platelets and megakaryocytes, these proteins have been shown to be important for proper platelet production and function. The cortactin family of proteins (Cttn & HS1) are known to regulate WASp-Arp2/3-mediated actin polymerisation in other cell types and so here we address the role of these proteins in platelets using knockout mouse models. We generated mice lacking Cttn and HS1 in the megakaryocyte/platelet lineage. These mice had normal platelet production, with platelet number, size and surface receptor profile comparable to controls. Platelet function was also unaffected by loss of Cttn/HS1 with no differences observed in a range of platelet function assays including aggregation, secretion, spreading, clot retraction or tyrosine phosphorylation. No effect on tail bleeding time or in thrombosis models was observed. In addition, platelet actin nodules, and megakaryocyte podosomes, actin-based structures known to be dependent on WASp and the Arp2/3 complex, formed normally. We conclude that despite the importance of WASp and the Arp2/3 complex in regulating F-actin dynamics in many cells types, the role of cortactin in their regulation appears to be fulfilled by other proteins in platelets.
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Affiliation(s)
- Steven G. Thomas
- Institute of Cardiovascular Sciences, Institute for Biomedical Research, The Medical School, University of Birmingham, Edgbaston, Birmingham, UK
| | - Natalie S. Poulter
- Institute of Cardiovascular Sciences, Institute for Biomedical Research, The Medical School, University of Birmingham, Edgbaston, Birmingham, UK
| | - Danai Bem
- Institute of Cardiovascular Sciences, Institute for Biomedical Research, The Medical School, University of Birmingham, Edgbaston, Birmingham, UK
| | - Brenda Finney
- Institute of Cardiovascular Sciences, Institute for Biomedical Research, The Medical School, University of Birmingham, Edgbaston, Birmingham, UK
| | - Laura M. Machesky
- Cancer Research UK Beatson Institute, College of Medical. Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Stephen P. Watson
- Institute of Cardiovascular Sciences, Institute for Biomedical Research, The Medical School, University of Birmingham, Edgbaston, Birmingham, UK
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22
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Chen X, Fan X, Tan J, Shi P, Wang X, Wang J, Kuang Y, Fei J, Liu J, Dang S, Wang Z. Palladin is involved in platelet activation and arterial thrombosis. Thromb Res 2016; 149:1-8. [PMID: 27865965 DOI: 10.1016/j.thromres.2016.11.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/31/2016] [Accepted: 11/09/2016] [Indexed: 10/20/2022]
Abstract
The dynamics of actin cytoskeleton have been shown to play a critical role during platelet activation. Palladin is an actin-associated protein, serving as a cytoskeleton scaffold to bundle actin fibers and actin cross linker. The functional role of palladin on platelet activation has not been investigated. Here, we characterized heterozygous palladin knockout (palladin+/-) mice to elucidate the platelet-related functions of palladin. The results showed that palladin was expressed in platelets and moderate palladin deficiency accelerated hemostasis and arterial thrombosis. The aggregation of palladin+/- platelets was increased in response to low levels of thrombin, U46619, and collagen. We also observed enhanced spreading of palladin+/- platelets on immobilized fibrinogen (Fg) and increased rate of clot retraction in platelet-rich plasma (PRP) containing palladin+/- platelets. Furthermore, the activation of the small GTPase Rac1 and Cdc42, which is associated with cytoskeletal dynamics and platelet activation signalings, was increased in the spreading and aggregating palladin+/- platelets compared to that in wild type platelets. Taken together, these findings indicated that palladin is involved in platelet activation and arterial thrombosis, implying a potent role of palladin in pathophysiology of thrombotic diseases.
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Affiliation(s)
- Xuejiao Chen
- State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai 200025, China; Shanghai Research Center for Model Organisms, Shanghai 201203, China
| | - Xuemei Fan
- Department of Biochemistry and Molecular Cell Biology, SJTUSM, Shanghai 200025, China
| | - Juan Tan
- State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai 200025, China; Shanghai Research Center for Model Organisms, Shanghai 201203, China
| | - Panlai Shi
- Department of Biochemistry and Molecular Cell Biology, SJTUSM, Shanghai 200025, China
| | - Xiyi Wang
- State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai 200025, China; Shanghai Research Center for Model Organisms, Shanghai 201203, China
| | - Jinjin Wang
- Shanghai Research Center for Model Organisms, Shanghai 201203, China
| | - Ying Kuang
- Shanghai Research Center for Model Organisms, Shanghai 201203, China
| | - Jian Fei
- Shanghai Research Center for Model Organisms, Shanghai 201203, China
| | - Junling Liu
- Department of Biochemistry and Molecular Cell Biology, SJTUSM, Shanghai 200025, China
| | - Suying Dang
- Department of Biochemistry and Molecular Cell Biology, SJTUSM, Shanghai 200025, China; Shanghai Research Center for Model Organisms, Shanghai 201203, China.
| | - Zhugang Wang
- State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai 200025, China; Shanghai Research Center for Model Organisms, Shanghai 201203, China.
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23
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Rondina MT, Freitag M, Pluthero FG, Kahr WHA, Rowley JW, Kraiss LW, Franks Z, Zimmerman GA, Weyrich AS, Schwertz H. Non-genomic activities of retinoic acid receptor alpha control actin cytoskeletal events in human platelets. J Thromb Haemost 2016; 14:1082-94. [PMID: 26848712 PMCID: PMC5497578 DOI: 10.1111/jth.13281] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Indexed: 12/29/2022]
Abstract
UNLABELLED Essentials Platelets employ proteins/signaling pathways traditionally thought reserved for nuclear niche. We determined retinoic-acid-receptor alpha (RARα) expression and function in human platelets. RARα/actin-related protein-2/3 complex (Arp2/3) interact via non-genomic signaling in platelets. RARα regulates Arp2/3-mediated actin cytoskeletal dynamics and platelet spreading. SUMMARY Background Platelets utilize proteins and pathways classically reserved for the nuclear niche. Methods We determined whether human platelets express retinoic-acid-receptor family members, traditionally thought of as nuclear transcription factors, and deciphered the function of RARα. Results We found that RARα is robustly expressed in human platelets and megakaryocytes and interacts directly with actin-related protein-2/3 complex (Arp2/3) subunit 5 (Arp2/3s5). Arp2/3s5 co-localized with RARα in situ and regulated platelet cytoskeletal processes. The RARα ligand all-trans retinoic acid (atRA) disrupted RARα-Arp2/3 interactions. When isolated human platelets were treated with atRA, rapid cytoskeletal events (e.g. platelet spreading) were inhibited. In addition, when platelets were cultured for 18 h in the presence of atRA, actin-dependent morphological changes (e.g. extended cell body formation) were similarly inhibited. Using in vitro actin branching assays, RARα and Arp2/3-regulated complex actin branch formation was demonstrated. Consistent with inhibition of cytoskeletal processes in platelets, atRA, when added to this branching assay, resulted in dysregulated actin branching. Conclusion Our findings identify a previously unknown mechanism by which RARα regulates Arp2/3-mediated actin cytoskeletal dynamics through a non-genomic signaling pathway. These findings have broad implications in both nucleated and anucleate cells, where actin cytoskeletal events regulate cell morphology, movement and division.
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Affiliation(s)
- M T Rondina
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
- Department of Internal Medicine, George E. Wahlen Salt Lake City VAMC, Salt Lake City, UT, USA
| | - M Freitag
- Department of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
| | - F G Pluthero
- Program in Cell Biology, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
| | - W H A Kahr
- Program in Cell Biology, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
- Departments of Paediatrics and Biochemistry, University of Toronto, Toronto, ON, Canada
| | - J W Rowley
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
| | - L W Kraiss
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Division of Vascular Surgery, Department of Surgery, University of Utah, Salt Lake City, UT, USA
| | - Z Franks
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
| | - G A Zimmerman
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - A S Weyrich
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - H Schwertz
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Department of Immunology and Transfusion Medicine, University of Greifswald, Greifswald, Germany
- Division of Vascular Surgery, Department of Surgery, University of Utah, Salt Lake City, UT, USA
- Lichtenberg-Professor for Experimental Hemostasis, University of Greifswald, Greifswald, Germany
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Fibrin activates GPVI in human and mouse platelets. Blood 2015; 126:1601-8. [PMID: 26282541 DOI: 10.1182/blood-2015-04-641654] [Citation(s) in RCA: 157] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 08/11/2015] [Indexed: 01/09/2023] Open
Abstract
The glycoprotein VI (GPVI)-Fc receptor γ (FcRγ) chain is the major platelet signaling receptor for collagen. Paradoxically, in a FeCl3 injury model, occlusion, but not initiation of thrombus formation, is delayed in GPVI-deficient and GPVI-depleted mice. In this study, we demonstrate that GPVI is a receptor for fibrin and speculate that this contributes to development of an occlusive thrombus. We observed a marked increase in tyrosine phosphorylation, including the FcRγ chain and Syk, in human and mouse platelets induced by thrombin in the presence of fibrinogen and the αIIbβ3 blocker eptifibatide. This was not seen in platelets stimulated by a protease activated receptor (PAR)-4 peptide, which is unable to generate fibrin from fibrinogen. The pattern of tyrosine phosphorylation was similar to that induced by activation of GPVI. Consistent with this, thrombin did not induce tyrosine phosphorylation of Syk and the FcRγ chain in GPVI-deficient mouse platelets. Mouse platelets underwent full spreading on fibrin but not fibrinogen, which was blocked in the presence of a Src kinase inhibitor or in the absence of GPVI. Spreading on fibrin was associated with phosphatidylserine exposure (procoagulant activity), and this too was blocked in GPVI-deficient platelets. The ectodomain of GPVI was shown to bind to immobilized monomeric and polymerized fibrin. A marked increase in embolization was seen following FeCl3 injury in GPVI-deficient mice, likely contributing to the delay in occlusion in this model. These results demonstrate that GPVI is a receptor for fibrin and provide evidence that this interaction contributes to thrombus growth and stability.
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Poulter NS, Pollitt AY, Davies A, Malinova D, Nash GB, Hannon MJ, Pikramenou Z, Rappoport JZ, Hartwig JH, Owen DM, Thrasher AJ, Watson SP, Thomas SG. Platelet actin nodules are podosome-like structures dependent on Wiskott-Aldrich syndrome protein and ARP2/3 complex. Nat Commun 2015; 6:7254. [PMID: 26028144 PMCID: PMC4458878 DOI: 10.1038/ncomms8254] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 04/21/2015] [Indexed: 11/09/2022] Open
Abstract
The actin nodule is a novel F-actin structure present in platelets during early spreading. However, only limited detail is known regarding nodule organization and function. Here we use electron microscopy, SIM and dSTORM super-resolution, and live-cell TIRF microscopy to characterize the structural organization and signalling pathways associated with nodule formation. Nodules are composed of up to four actin-rich structures linked together by actin bundles. They are enriched in the adhesion-related proteins talin and vinculin, have a central core of tyrosine phosphorylated proteins and are depleted of integrins at the plasma membrane. Nodule formation is dependent on Wiskott–Aldrich syndrome protein (WASp) and the ARP2/3 complex. WASp−/− mouse blood displays impaired platelet aggregate formation at arteriolar shear rates. We propose actin nodules are platelet podosome-related structures required for platelet–platelet interaction and their absence contributes to the bleeding diathesis of Wiskott–Aldrich syndrome. During early platelet spreading a novel F-actin structure forms, called the actin nodule. Here Poulter et al. demonstrate that actin nodule formation depends on WASp and the Arp2/3 complex, and using super-resolution microscopy they show that nodules bear a structural resemblance to podosomes.
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Affiliation(s)
- Natalie S Poulter
- Centre for Cardiovascular Sciences, The Medical School, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Alice Y Pollitt
- Centre for Cardiovascular Sciences, The Medical School, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Amy Davies
- PSIBS doctoral training centre, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Dessislava Malinova
- Molecular Immunology Unit, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Gerard B Nash
- Centre for Cardiovascular Sciences, The Medical School, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Mike J Hannon
- PSIBS doctoral training centre, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Zoe Pikramenou
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Joshua Z Rappoport
- The Center for Advanced Microscopy and Nikon Imaging Center, Morton 2-681, Northwestern University Feinberg School of Medicine, 303 E. Chicago Avenue, Chicago, Illinois 60611, USA
| | - John H Hartwig
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Dylan M Owen
- Randall Division of Cell and Molecular Biophysics, New Hunt's House, King's College London, Guy's Campus, London SE1 1UL, UK
| | - Adrian J Thrasher
- Molecular Immunology Unit, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Stephen P Watson
- Centre for Cardiovascular Sciences, The Medical School, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Steven G Thomas
- Centre for Cardiovascular Sciences, The Medical School, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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Mori J, Wang YJ, Ellison S, Heising S, Neel BG, Tremblay ML, Watson SP, Senis YA. Dominant Role of the Protein-Tyrosine Phosphatase CD148 in Regulating Platelet Activation Relative to Protein-Tyrosine Phosphatase-1B. Arterioscler Thromb Vasc Biol 2012; 32:2956-65. [DOI: 10.1161/atvbaha.112.300447] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Objective—
The receptor-like protein-tyrosine phosphatase (PTP) CD148 and the nontransmembrane PTP1-B have been shown to be net positive regulators of Src family kinases in platelets. In the present study, we compared the relative contributions of these PTPs in platelet activation by the major glycoprotein, glycoprotein VI, α
IIb
β
3
, and C-type lectin-like receptor 2 (CLEC-2).
Methods and Results—
PTP-1B–deficient mouse platelets responded normally to the glycoprotein VI–specific agonist collagen-related peptide and antibody-mediated CLEC-2 activation. However, they exhibited a marginal reduction in α
IIb
β
3
-mediated Src family kinase activation and tyrosine phosphorylation. In contrast, CD148-deficient platelets exhibited a dramatic reduction in activation by glycoprotein VI and α
IIb
β
3
and a marginal reduction in response to activation by CLEC-2, which was further enhanced in the absence of PTP-1B. These defects were associated with reduced activation of Src family kinase and spleen tyrosine kinase, suggesting a causal relationship. Under arteriolar flow conditions, there was defective aggregate formation in the absence of PTP-1B and, to a greater extent, CD148 and a severe abrogation of both adhesion and aggregation in the absence of both PTPs.
Conclusion—
Findings from this study demonstrate that CD148 plays a dominant role in activating Src family kinases in platelets relative to PTP-1B. Both PTPs are required for optimal platelet activation and aggregate formation under high arterial shear rates.
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Affiliation(s)
- Jun Mori
- From the Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom (J.M., Y.J.W., S.E., S.H., S.P.W, Y.A.S.); Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Hospital, University Health Network and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada (B.G.N.); and Goodman Cancer
| | - Ying-Jie Wang
- From the Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom (J.M., Y.J.W., S.E., S.H., S.P.W, Y.A.S.); Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Hospital, University Health Network and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada (B.G.N.); and Goodman Cancer
| | - Stuart Ellison
- From the Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom (J.M., Y.J.W., S.E., S.H., S.P.W, Y.A.S.); Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Hospital, University Health Network and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada (B.G.N.); and Goodman Cancer
| | - Silke Heising
- From the Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom (J.M., Y.J.W., S.E., S.H., S.P.W, Y.A.S.); Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Hospital, University Health Network and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada (B.G.N.); and Goodman Cancer
| | - Benjamin G. Neel
- From the Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom (J.M., Y.J.W., S.E., S.H., S.P.W, Y.A.S.); Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Hospital, University Health Network and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada (B.G.N.); and Goodman Cancer
| | - Michel L. Tremblay
- From the Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom (J.M., Y.J.W., S.E., S.H., S.P.W, Y.A.S.); Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Hospital, University Health Network and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada (B.G.N.); and Goodman Cancer
| | - Steve P. Watson
- From the Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom (J.M., Y.J.W., S.E., S.H., S.P.W, Y.A.S.); Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Hospital, University Health Network and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada (B.G.N.); and Goodman Cancer
| | - Yotis A. Senis
- From the Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom (J.M., Y.J.W., S.E., S.H., S.P.W, Y.A.S.); Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Hospital, University Health Network and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada (B.G.N.); and Goodman Cancer
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Schachtner H, Li A, Stevenson D, Calaminus SDJ, Thomas S, Watson SP, Sixt M, Wedlich-Soldner R, Strathdee D, Machesky LM. Tissue inducible Lifeact expression allows visualization of actin dynamics in vivo and ex vivo. Eur J Cell Biol 2012; 91:923-929. [PMID: 22658956 PMCID: PMC3930012 DOI: 10.1016/j.ejcb.2012.04.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 04/01/2012] [Accepted: 04/12/2012] [Indexed: 11/21/2022] Open
Abstract
We describe here the development and characterization of a conditionally inducible mouse model expressing Lifeact-GFP, a peptide that reports the dynamics of filamentous actin. We have used this model to study platelets, megakaryocytes and melanoblasts and we provide evidence that Lifeact-GFP is a useful reporter in these cell types ex vivo. In the case of platelets and megakaryocytes, these cells are not transfectable by traditional methods, so conditional activation of Lifeact allows the study of actin dynamics in these cells live. We studied melanoblasts in native skin explants from embryos, allowing the visualization of live actin dynamics during cytokinesis and migration. Our study revealed that melanoblasts lacking the small GTPase Rac1 show a delay in the formation of new pseudopodia following cytokinesis that accounts for the previously reported cytokinesis delay in these cells. Thus, through use of this mouse model, we were able to gain insights into the actin dynamics of cells that could only previously be studied using fixed specimens or following isolation from their native tissue environment.
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Affiliation(s)
- Hannah Schachtner
- The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Bearsden, Glasgow, G61 1BD
| | - Ang Li
- The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Bearsden, Glasgow, G61 1BD
| | - David Stevenson
- The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Bearsden, Glasgow, G61 1BD
| | - Simon D. J. Calaminus
- The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Bearsden, Glasgow, G61 1BD
| | - Steve Thomas
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT
| | - Steve P. Watson
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT
| | - Michael Sixt
- Institute of Science and Technology, Am Campus 1, A-3400 Klosterneuberg, Austria
| | - Roland Wedlich-Soldner
- Cellular Dynamics and Cell Patterning, Max-Planck Institute of Biochemistry, Am, Klopferspitz 18, 82152 Martinsried, Germany
| | - Douglas Strathdee
- The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Bearsden, Glasgow, G61 1BD
| | - Laura M. Machesky
- The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Bearsden, Glasgow, G61 1BD
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Abstract
Abstract
The crucial function of blood platelets in hemostasis is to prevent blood loss by stable thrombus formation. This process is driven by orchestrated mechanisms including several signal transduction cascades and morphologic transformations. The cytoplasmic microtubule modulator RanBP10 is a Ran and β1-tubulin binding protein that is essential for platelet granule release and mice lacking RanBP10 harbor a severe bleeding phenotype. In this study, we demonstrate that RanBP10-nullizygous platelets show normal adhesion on collagen and von Willebrand factor under flow conditions. However, using a ferric chloride-induced arterial thrombosis model, the formation of stable thrombi was significantly impaired, preventing vessel occlusion or leading to recanalization and thromboembolization. Delta-granule secretion was normal in mutant mice, whereas platelet shape change in aggregometry was attenuated. Lack of RanBP10 leads to increased β1-tubulin protein, which drives α-monomers into polymerized microtubules. In mutant platelets agonists failed to contract the peripheral marginal band or centralize granules. Pretreatment of wild-type platelets with taxol caused microtubule stabilization and phenocopied the attenuated shape change in response to collagen, suggesting that RanBP10 inhibits premature microtubule polymerization of β1-tubulin and plays a pivotal role in thrombus stabilization.
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Kuchay SM, Wieschhaus AJ, Marinkovic M, Herman IM, Chishti AH. Targeted gene inactivation reveals a functional role of calpain-1 in platelet spreading. J Thromb Haemost 2012; 10:1120-32. [PMID: 22458296 PMCID: PMC3956748 DOI: 10.1111/j.1538-7836.2012.04715.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND Calpains are implicated in a wide range of cellular functions including the maintenance of hemostasis via the regulation of cytoskeletal modifications in platelets. OBJECTIVES Determine the functional role of calpain isoforms in platelet spreading. METHODS AND RESULTS Platelets from calpain-1(-/-) mice show enhanced spreading on collagen- and fibrinogen-coated surfaces as revealed by immunofluorescence, differential interference contrast (DIC) and scanning electron microscopy. The treatment of mouse platelets with MDL, a cell permeable inhibitor of calpains 1/2, resulted in increased spreading. The PTP1B-mediated enhanced tyrosine dephosphorylation in calpain-1(-/-) platelets did not fully account for the enhanced spreading as platelets from the double knockout mice lacking calpain-1 and PTP1B showed only a partial rescue of the spreading phenotype. In non-adherent platelets, proteolysis and GTPase activity of RhoA and Rac1 were indistinguishable between the wild-type (WT) and calpain-1(-/-) platelets. In contrast, the ECM-adherent calpain-1(-/-) platelets showed higher Rac1 activity at the beginning of spreading, whereas RhoA was more active at later time points. The ECM-adherent calpain-1(-/-) platelets showed an elevated level of RhoA protein but not Rac1 and Cdc42. Proteolysis of recombinant RhoA, but not Rac1 and Cdc42, indicates that RhoA is a calpain-1 substrate in vitro. CONCLUSIONS Potentiation of the platelet spreading phenotype in calpain-1(-/-) mice suggests a novel role of calpain-1 in hemostasis, and may explain the normal bleeding time observed in the calpain-1(-/-) mice.
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Affiliation(s)
- S M Kuchay
- Department of Pharmacology, University of Illinois College of Medicine, Chicago, IL, USA
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31
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Lee D, Fong KP, King MR, Brass LF, Hammer DA. Differential dynamics of platelet contact and spreading. Biophys J 2012; 102:472-82. [PMID: 22325269 DOI: 10.1016/j.bpj.2011.10.056] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 09/19/2011] [Accepted: 10/18/2011] [Indexed: 11/27/2022] Open
Abstract
Platelet spreading is critical for hemostatic plug formation and thrombosis. However, the detailed dynamics of platelet spreading as a function of receptor-ligand adhesive interactions has not been thoroughly investigated. Using reflection interference contrast microscopy, we found that both adhesive interactions and PAR4 activation affect the dynamics of platelet membrane contact formation during spreading. The initial growth of close contact area during spreading was controlled by the combination of different immobilized ligands or PAR4 activation on fibrinogen, whereas the growth of the total area of spreading was independent of adhesion type and PAR4 signaling. We found that filopodia extend to their maximal length and then contract over time; and that filopodial protrusion and expansion were affected by PAR4 signaling. Upon PAR4 activation, the integrin α(IIb)β(3) mediated close contact to fibrinogen substrata and led to the formation of ringlike patterns in the platelet contact zone. A systematic study of platelet spreading of GPVI-, α(2)-, or β(3)-deficient platelets on collagen or fibrinogen suggests the integrin α(2) is indispensable for spreading on collagen. The platelet collagen receptors GPVI and α(2) regulate integrin α(IIb)β(3)-mediated platelet spreading on fibrinogen. This work elucidates quantitatively how receptor-ligand adhesion and biochemical signals synergistically control platelet spreading.
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Affiliation(s)
- Dooyoung Lee
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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32
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Abstract
Hemostasis is dependent upon the successful recruitment and activation of blood platelets to the site of a breach in the vasculature. Platelet activation stimulates the rapid reorganization of the cortical actin cytoskeleton, resulting in the transformation of platelets from biconcave disks to fully spread cells. During this process, platelets extend filopodia and generate lamellipodia, resulting in a dramatic increase in the platelet surface area. Kohler-illuminated Nomarski Differential Interference Contrast microscopy has proved an effective tool to characterize platelet morphological changes in real time, and provides a useful tool to identify genetic and pharmacological regulators of platelet function.
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33
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Thomas SG, Calaminus SDJ, Machesky LM, Alberts AS, Watson SP. G-protein coupled and ITAM receptor regulation of the formin FHOD1 through Rho kinase in platelets. J Thromb Haemost 2011; 9:1648-51. [PMID: 21605332 DOI: 10.1111/j.1538-7836.2011.04357.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Mitsios JV, Prévost N, Kasirer-Friede A, Gutierrez E, Groisman A, Abrams CS, Wang Y, Litvinov RI, Zemljic-Harpf A, Ross RS, Shattil SJ. What is vinculin needed for in platelets? J Thromb Haemost 2010; 8:2294-304. [PMID: 20670372 PMCID: PMC2965783 DOI: 10.1111/j.1538-7836.2010.03998.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
UNLABELLED Summary. BACKGROUND Vinculin links integrins to the cell cytoskeleton by virtue of its binding to proteins such as talin and F-actin. It has been implicated in the transmission of mechanical forces from the extracellular matrix to the cytoskeleton of migrating cells. Vinculin's function in platelets is unknown. OBJECTIVE To determine whether vinculin is required for the functions of platelets and their major integrin, α(IIb) β(3) . METHODS The murine vinculin gene (Vcl) was deleted in the megakaryocyte/platelet lineage by breeding Vcl fl/fl mice with Pf4-Cre mice. Platelet and integrin functions were studied in vivo and ex vivo. RESULTS Vinculin was undetectable in platelets from Vcl fl/fl Cre(+) mice, as determined by immunoblotting and fluorescence microscopy. Vinculin-deficient megakaryocytes exhibited increased membrane tethers in response to mechanical pulling on α(IIb) β(3) with laser tweezers, suggesting that vinculin helps to maintain membrane cytoskeleton integrity. Surprisingly, vinculin-deficient platelets displayed normal agonist-induced fibrinogen binding to α(IIb) β(3) , aggregation, spreading, actin polymerization/organization, clot retraction and the ability to form a procoagulant surface. Furthermore, vinculin-deficient platelets adhered to immobilized fibrinogen or collagen normally, under both static and flow conditions. Tail bleeding times were prolonged in 59% of vinculin-deficient mice. However, these mice exhibited no spontaneous bleeding and they formed occlusive platelet thrombi comparable to those in wild-type littermates in response to carotid artery injury with FeCl(3) . CONCLUSION Despite promoting membrane cytoskeleton integrity when mechanical force is applied to α(IIb) β(3) , vinculin is not required for the traditional functions of α(IIb) β(3) or the platelet actin cytoskeleton.
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Affiliation(s)
- John V. Mitsios
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Nicolas Prévost
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Ana Kasirer-Friede
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Edgar Gutierrez
- Department of Physics, University of California, San Diego, La Jolla, CA 92093
| | - Alex Groisman
- Department of Physics, University of California, San Diego, La Jolla, CA 92093
| | - Charles S. Abrams
- Department of Medicine and Cell, University of Pennsylvania School of Medicine, Philadelphia, PA 19104
| | - Yanfeng Wang
- Department of Medicine and Cell, University of Pennsylvania School of Medicine, Philadelphia, PA 19104
| | - Rustem I. Litvinov
- Department of Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104
| | - Alice Zemljic-Harpf
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
- VA Healthcare San Diego, San Diego, CA 92161
| | - Robert S. Ross
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
- VA Healthcare San Diego, San Diego, CA 92161
| | - Sanford J. Shattil
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
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Poulter NS, Staiger CJ, Rappoport JZ, Franklin-Tong VE. Actin-binding proteins implicated in the formation of the punctate actin foci stimulated by the self-incompatibility response in Papaver. PLANT PHYSIOLOGY 2010; 152:1274-83. [PMID: 20081043 PMCID: PMC2832276 DOI: 10.1104/pp.109.152066] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Accepted: 01/13/2010] [Indexed: 05/21/2023]
Abstract
The actin cytoskeleton is a key target for signaling networks and plays a central role in translating signals into cellular responses in eukaryotic cells. Self-incompatibility (SI) is an important mechanism responsible for preventing self-fertilization. The SI system of Papaver rhoeas pollen involves a Ca(2+)-dependent signaling network, including massive actin depolymerization as one of the earliest cellular responses, followed by the formation of large actin foci. However, no analysis of these structures, which appear to be aggregates of filamentous (F-)actin based on phalloidin staining, has been carried out to date. Here, we characterize and quantify the formation of F-actin foci in incompatible Papaver pollen tubes over time. The F-actin foci increase in size over time, and we provide evidence that their formation requires actin polymerization. Once formed, these SI-induced structures are unusually stable, being resistant to treatments with latrunculin B. Furthermore, their formation is associated with changes in the intracellular localization of two actin-binding proteins, cyclase-associated protein and actin-depolymerizing factor. Two other regulators of actin dynamics, profilin and fimbrin, do not associate with the F-actin foci. This study provides, to our knowledge, the first insights into the actin-binding proteins and mechanisms involved in the formation of these intriguing structures, which appear to be actively formed during the SI response.
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Dittrich M, Strassberger V, Fackler M, Tas P, Lewandrowski U, Sickmann A, Walter U, Dandekar T, Birschmann I. Characterization of a novel interaction between vasodilator-stimulated phosphoprotein and Abelson interactor 1 in human platelets: a concerted computational and experimental approach. Arterioscler Thromb Vasc Biol 2010; 30:843-50. [PMID: 20110575 DOI: 10.1161/atvbaha.109.200683] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The goal of this study was systematic profiling of vasodilator-stimulated phosphoprotein (VASP)-Ena/VASP homology 1 (EVH1) interactors in human platelets using a combined in silico and in vitro approach. METHODS AND RESULTS Exploiting the information of the comprehensive proteome catalogue in the PlateletWeb database (http://plateletweb.bioapps.biozentrum.uni-wuerzburg.de/PlateletWeb.php), we performed a motif search of all sequences and identified potential target sites of class I EVH1 domains in human platelet proteins. Performing affinity purification with VASP-EVH1 domain and the lysates of platelets, we examined complex partners by mass spectrometry. Combining the results of both analyses, we identified Abelson interactor 1 (Abi-1) as a novel EVH1 domain-specific interaction partner of VASP in human platelets and investigated this interaction by yeast 2-hybrid mutational studies and immunoprecipitation. Immunofluorescence microscopy indicated colocalization of both proteins at the lamellipodia of spread human platelets, suggesting a role in reorganizing the cytoskeleton during spreading. CONCLUSIONS The combination of experimental and computational interactome research has emerged as a valuable tool for the analysis of protein-protein interaction networks and facilitates the discovery and characterization of novel interactions as detailed here for Abi-1 and VASP in human platelets. System biological approaches can be expected to play an important role in basic and clinical platelet research, as they offer the potential to analyze signal transduction beyond the scope of established pathways.
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Affiliation(s)
- Marcus Dittrich
- Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany
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37
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Abstract
Binding of platelets to fibrinogen via integrin alphaIIbbeta3 stimulates cytoskeletal reorganization and spreading. These responses depend on tyrosine phosphorylation of multiple proteins by Src family members and Syk. Among Src substrates in platelets is adhesion- and degranulation-promoting adapter protein (ADAP), an adapter with potential binding partners: SLP-76, VASP, and SKAP-HOM. During studies of platelet function under shear flow, we discovered that ADAP(-/-) mouse platelets, unlike ADAP+/+ platelets, formed unstable thrombi in response to carotid artery injury. Moreover, fibrinogen-adherent ADAP(-/-) platelets in shear flow ex vivo showed reduced spreading and smaller zones of contact with the matrix. These abnormalities were not observed under static conditions, and they could not be rescued by stimulating platelets with a PAR4 receptor agonist or by direct alphaIIbbeta3 activation with MnCl2, consistent with a defect in outside-in alphaIIbbeta3 signaling. ADAP+/+ platelets subjected to shear flow assembled F-actin-rich structures that colocalized with SLP-76 and the Rac1 exchange factor, phospho-Vav1. In contrast, platelets deficient in ADAP, but not those deficient in VASP or SKAP-HOM, failed to form these structures. These results establish that ADAP is an essential component of alphaIIbbeta3-mediated platelet mechanotransduction that promotes F-actin assembly and enables platelet spreading and thrombus stabilization under fluid shear stress.
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White JG, Burris SM, Crowe BR. GATA-1, G208S macrothrombocytes are deficient in talin: immunofluorescence studies. Platelets 2009; 20:216-24. [PMID: 19437340 DOI: 10.1080/09537100902818344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Previous investigations from our laboratory identified the ultrastructural pathology and cytochemistry of macrothrombocytes (MTC) from patients with the X-linked, G208S varient of the GATA-1 mutation.A subsequent biochemical study of the MTC cytoskeletal proteins using polyacrylamide gel electrophoresis and western blot analysis revealed the MTC were deficient in the high-molecular weight, actin binding protein, talin. The present study has used immunofluorescent techniques to further characterize the talin deficiency. Results confirm that the GATA-1, G208S MTC are deficient in talin, and what little is present relocates to the undersurface of the plasma membrane following activations where it associates with adhesion plaques.
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Affiliation(s)
- James G White
- Department of Laboratory Medicine, Pathology and Pediatrics, University of Minnesota School of Medicine, Minneapolis, MN, USA.
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