1
|
Kawano S, Noda C, Itoh S, Urabe A, Fujii C, Ogawa I, Suzuki R, Hida S. Staphylococcal superantigen-like protein 3 triggers murine mast cell adhesion by binding to CD43 and augments mast cell activation. Genes Cells 2024; 29:397-416. [PMID: 38454012 DOI: 10.1111/gtc.13111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 02/16/2024] [Accepted: 02/19/2024] [Indexed: 03/09/2024]
Abstract
Staphylococcus aureus is a noteworthy pathogen in allergic diseases, as four staphylococcal exotoxins activate mast cells, a significant contributor to inflammation, in an IgE-independent manner. Although the adhesion of mast cells is an essential process for their immune responses, only a small number of exotoxins have been reported to affect the process. Here, we demonstrated that staphylococcal superantigen-like (SSL) 3, previously identified as a toll-like receptor 2 agonist, induced the adhesion of murine bone marrow-derived mast cells to culture substratum. SSL3-induced adhesion was mediated by fibronectin in an Arg-Gly-Asp (RGD) sequence-dependent manner, suggesting the integrins were involved in the process. Additionally, SSL3 was found to bind to an anti-adhesive surface protein CD43. SSL3 induced the adhesion of HEK293 cells expressing exogenous CD43, suggesting that CD43 is the target molecule for adhesion induced by SSL3. Evaluation of SSL3-derived mutants showed that the C-terminal region (253-326), specifically T285 and H307, are necessary to induce adhesion. SSL3 augmented the IL-13 production of mast cells in response to immunocomplex and SSL12. These findings reveal a novel function of SSL3, triggering cell adhesion and enhancing mast cell activation. This study would clarify the correlation between S. aureus and allergic diseases such as atopic dermatitis.
Collapse
Affiliation(s)
- Sae Kawano
- Department of Molecular and Cellular Health Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi Prefecture, Japan
| | - Chisaki Noda
- Department of Molecular and Cellular Health Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi Prefecture, Japan
| | - Saotomo Itoh
- Department of Molecular and Cellular Health Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi Prefecture, Japan
| | - Ayaka Urabe
- Department of Molecular and Cellular Health Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi Prefecture, Japan
| | - Chifumi Fujii
- Department of Biotechnology, Institute for Biomedical Sciences, Shinshu University, Matsumoto, Nagano Prefecture, Japan
- Department of Molecular Pathology, Shinshu University School of Medicine, Matsumoto, Nagano Prefecture, Japan
- Center for Medical Education and Clinical Training, Shinshu University School of Medicine, Matsumoto, Nagano Prefecture, Japan
| | - Isamu Ogawa
- Department of Molecular and Cellular Health Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi Prefecture, Japan
| | - Ryo Suzuki
- Laboratory of Hygienic Chemistry, Faculty of Pharmaceutical Science, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa Prefecture, Japan
| | - Shigeaki Hida
- Department of Molecular and Cellular Health Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi Prefecture, Japan
| |
Collapse
|
2
|
Guinard I, Nguyen T, Brassard-Jollive N, Weber J, Ruch L, Reininger L, Brouard N, Eckly A, Collin D, Lanza F, Léon C. Matrix stiffness controls megakaryocyte adhesion, fibronectin fibrillogenesis, and proplatelet formation through Itgβ3. Blood Adv 2023; 7:4003-4018. [PMID: 37171626 PMCID: PMC10410137 DOI: 10.1182/bloodadvances.2022008680] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 04/13/2023] [Accepted: 04/17/2023] [Indexed: 05/13/2023] Open
Abstract
Megakaryocytes (MKs) are the precursor cells of platelets, located in the bone marrow (BM). Once mature, they extend elongated projections named proplatelets through sinusoid vessels, emerging from the marrow stroma into the circulating blood. Not all signals from the microenvironment that regulate proplatelet formation are understood, particularly those from the BM biomechanics. We sought to investigate how MKs perceive and adapt to modifications of the stiffness of their environment. Although the BM is one of the softest tissue of the body, its rigidification results from excess fibronectin (FN), and other matrix protein deposition occur upon myelofibrosis. Here, we have shown that mouse MKs are able to detect the stiffness of a FN-coated substrate and adapt their morphology accordingly. Using a polydimethylsiloxane substrate with stiffness varying from physiological to pathological marrow, we found that a stiff matrix favors spreading, intracellular contractility, and FN fibrils assembly at the expense of proplatelet formation. Itgb3, but not Itgb1, is required for stiffness sensing, whereas both integrins are involved in fibrils assembly. In contrast, soft substrates promote proplatelet formation in an Itgb3-dependent manner, consistent with the ex vivo decrease in proplatelet formation and the in vivo decrease in platelet number in Itgb3-deficient mice. Our findings demonstrate the importance of environmental stiffness for MK functions with potential pathophysiological implications during pathologies that deregulate FN deposition and modulate stiffness in the marrow.
Collapse
Affiliation(s)
- Ines Guinard
- UMR_S1255, INSERM, Etablissement Français du Sang-Grand Est, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Thao Nguyen
- UMR_S1255, INSERM, Etablissement Français du Sang-Grand Est, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Noémie Brassard-Jollive
- UMR_S1255, INSERM, Etablissement Français du Sang-Grand Est, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Josiane Weber
- UMR_S1255, INSERM, Etablissement Français du Sang-Grand Est, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Laurie Ruch
- UMR_S1255, INSERM, Etablissement Français du Sang-Grand Est, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Laura Reininger
- UMR_S1255, INSERM, Etablissement Français du Sang-Grand Est, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Nathalie Brouard
- UMR_S1255, INSERM, Etablissement Français du Sang-Grand Est, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Anita Eckly
- UMR_S1255, INSERM, Etablissement Français du Sang-Grand Est, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | | | - François Lanza
- UMR_S1255, INSERM, Etablissement Français du Sang-Grand Est, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Catherine Léon
- UMR_S1255, INSERM, Etablissement Français du Sang-Grand Est, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| |
Collapse
|
3
|
Cai D, Weng W. Development potential of extracellular matrix hydrogels as hemostatic materials. Front Bioeng Biotechnol 2023; 11:1187474. [PMID: 37383519 PMCID: PMC10294235 DOI: 10.3389/fbioe.2023.1187474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 06/02/2023] [Indexed: 06/30/2023] Open
Abstract
The entry of subcutaneous extracellular matrix proteins into the circulation is a key step in hemostasis initiation after vascular injury. However, in cases of severe trauma, extracellular matrix proteins are unable to cover the wound, making it difficult to effectively initiate hemostasis and resulting in a series of bleeding events. Acellular-treated extracellular matrix (ECM) hydrogels are widely used in regenerative medicine and can effectively promote tissue repair due to their high mimic nature and excellent biocompatibility. ECM hydrogels contain high concentrations of extracellular matrix proteins, including collagen, fibronectin, and laminin, which can simulate subcutaneous extracellular matrix components and participate in the hemostatic process. Therefore, it has unique advantages as a hemostatic material. This paper first reviewed the preparation, composition and structure of extracellular hydrogels, as well as their mechanical properties and safety, and then analyzed the hemostatic mechanism of the hydrogels to provide a reference for the application and research, and development of ECM hydrogels in the field of hemostasis.
Collapse
|
4
|
David V, Wermelinger LS, Frattani FS, Lima AGF, Santos YFS, Mourão PADS, Almeida FCL, Kurtenbach E, Zingali RB. rJararacin, a recombinant disintegrin from Bothrops jararaca venom: Exploring its effects on hemostasis and thrombosis. Arch Biochem Biophys 2023; 738:109557. [PMID: 36878339 DOI: 10.1016/j.abb.2023.109557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/24/2023] [Accepted: 03/02/2023] [Indexed: 03/07/2023]
Abstract
Integrins are a family of heterodimeric transmembrane receptors which link the extracellular matrix to the cell cytoskeleton. These receptors play a role in many cellular processes: adhesion, proliferation, migration, apoptosis, and platelet aggregation, thus modulating a wide range of scenarios in health and disease. Therefore, integrins have been the target of new antithrombotic drugs. Disintegrins from snake venoms are recognized by the ability to modulate the activity of integrins, such as integrin αIIbβ3, a fundamental platelet glycoprotein, and αvβ3 expressed on tumor cells. For this reason, disintegrins are unique and potential tools for examining integrin-matrix interaction and the development of novel antithrombotic agents. The present study aims to obtain the recombinant form of jararacin and evaluate the secondary structure and its effects on hemostasis and thrombosis. rJararacin was expressed in the Pichia pastoris (P. pastoris) expression system and purified the recombinant protein with a yield of 40 mg/L of culture. The molecular mass (7722 Da) and internal sequence were confirmed by mass spectrometry. Structure and folding analysis were obtained by Circular Dichroism and 1H Nuclear Magnetic Resonance spectra. Disintegrin structure reveals properly folded with the presence of β-sheet structure. rJararacin significantly demonstrated inhibition of the adhesion of B16F10 cells and platelets to the fibronectin matrix under static conditions. rJararacin inhibited platelet aggregation induced by ADP (IC50 95 nM), collagen (IC50 57 nM), and thrombin (IC50 22 nM) in a dose-dependent manner. This disintegrin also inhibited 81% and 94% of the adhesion of platelets to fibrinogen and collagen under continuous flow, respectively. In addition, rjararacin efficaciously prevents platelet aggregation in vitro and ex vivo with rat platelets and thrombus occlusion at an effective dose (5 mg/kg). The data here provides evidence that rjararacin possesses the potential as an αIIbβ3 antagonist, capable of preventing arterial thrombosis.
Collapse
Affiliation(s)
- Victor David
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, CEP 21941-902, Brazil.
| | - Luciana Serrão Wermelinger
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, CEP 21941-170, Brazil.
| | - Flávia Serra Frattani
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, CEP 21941-170, Brazil.
| | - Antonio Gilclêr Ferreira Lima
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, CEP 21941-902, Brazil.
| | - Yasmyn Fernandes Silva Santos
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, CEP 21941-902, Brazil.
| | - Paulo Antônio de Souza Mourão
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, CEP 21941-902, Brazil.
| | - Fabio Ceneviva Lacerda Almeida
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, CEP 21941-902, Brazil.
| | - Eleonora Kurtenbach
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, CEP 21941-170, Brazil.
| | - Russolina Benedeta Zingali
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, CEP 21941-902, Brazil.
| |
Collapse
|
5
|
Bennett C, Lawrence M, Guerrero JA, Stritt S, Waller AK, Yan Y, Mifsud RW, Ballester-Beltran J, Baig A, Mueller A, Mayer L, Warland J, Penkett CJ, Akbari P, Moreau T, Evans AL, Mookerjee S, Hoffman GJ, Saeb-Parsy K, Adams DJ, Couzens AL, Bender M, Erber WN, Nieswandt B, Read RJ, Ghevaert C. CRLF3 plays a key role in the final stage of platelet genesis and is a potential therapeutic target for thrombocythemia. Blood 2022; 139:2227-2239. [PMID: 35051265 PMCID: PMC7614665 DOI: 10.1182/blood.2021013113] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 11/23/2021] [Indexed: 11/20/2022] Open
Abstract
The process of platelet production has so far been understood to be a 2-stage process: megakaryocyte maturation from hematopoietic stem cells followed by proplatelet formation, with each phase regulating the peripheral blood platelet count. Proplatelet formation releases into the bloodstream beads-on-a-string preplatelets, which undergo fission into mature platelets. For the first time, we show that preplatelet maturation is a third, tightly regulated, critical process akin to cytokinesis that regulates platelet count. We show that deficiency in cytokine receptor-like factor 3 (CRLF3) in mice leads to an isolated and sustained 25% to 48% reduction in the platelet count without any effect on other blood cell lineages. We show that Crlf3-/- preplatelets have increased microtubule stability, possibly because of increased microtubule glutamylation via the interaction of CRLF3 with key members of the Hippo pathway. Using a mouse model of JAK2 V617F essential thrombocythemia, we show that a lack of CRLF3 leads to long-term lineage-specific normalization of the platelet count. We thereby postulate that targeting CRLF3 has therapeutic potential for treatment of thrombocythemia.
Collapse
Affiliation(s)
- Cavan Bennett
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
| | - Moyra Lawrence
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
- Cambridge Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Jose A. Guerrero
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
| | - Simon Stritt
- Institute of Experimental Biomedicine, University Hospital and University of Würzburg, Josef-Schneider-Str. 2, 97080 Würzburg, Germany
| | - Amie K. Waller
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
- Cambridge Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Yahui Yan
- Cambridge Institute for Medical Research and Department of Haematology, University of Cambridge, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, England
| | - Richard W. Mifsud
- Cambridge Institute for Medical Research and Department of Haematology, University of Cambridge, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, England
| | - Jose Ballester-Beltran
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
| | - Ayesha Baig
- Institute of Experimental Biomedicine, University Hospital and University of Würzburg, Josef-Schneider-Str. 2, 97080 Würzburg, Germany
| | - Annett Mueller
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
- Cambridge Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Louisa Mayer
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
| | - James Warland
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
- Cambridge Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Christopher J. Penkett
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
| | - Parsa Akbari
- MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Strangeways Research Laboratory, Wort’s Causeway, Cambridge CB1 8RN, UK
- Department of Human Genetics, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1HH, UK
| | - Thomas Moreau
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
| | - Amanda L. Evans
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
- Cambridge Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Souradip Mookerjee
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
- Cambridge Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Gary J. Hoffman
- Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, Crawley, WA, 6099, Australia
| | - Kourosh Saeb-Parsy
- Department of Surgery, University of Cambridge, and NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - David J. Adams
- The Wellcome Trust Sanger Institute, Wellcome Genome Campus, Cambridge, CB10 1HH, UK
| | - Amber L. Couzens
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5G 1X5, Canada
| | - Markus Bender
- Institute of Experimental Biomedicine, University Hospital and University of Würzburg, Josef-Schneider-Str. 2, 97080 Würzburg, Germany
| | - Wendy N. Erber
- Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, Crawley, WA, 6099, Australia
| | - Bernhard Nieswandt
- Institute of Experimental Biomedicine, University Hospital and University of Würzburg, Josef-Schneider-Str. 2, 97080 Würzburg, Germany
| | - Randy J. Read
- Cambridge Institute for Medical Research and Department of Haematology, University of Cambridge, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, England
| | - Cedric Ghevaert
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK
- Cambridge Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge CB2 0AW, UK
| |
Collapse
|
6
|
Lee YY, Kim SD, Park SC, Rhee MH. Panax ginseng: Inflammation, platelet aggregation, thrombus formation, and atherosclerosis crosstalk. J Ginseng Res 2022; 46:54-61. [PMID: 35058727 PMCID: PMC8753522 DOI: 10.1016/j.jgr.2021.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/08/2021] [Accepted: 09/08/2021] [Indexed: 12/20/2022] Open
Abstract
Ginseng has been widely studied due to its various therapeutic properties on various diseases such as cardiovascular disease (CVD). Cardiovascular disease has been canonically known to be caused by high levels of low-density lipoproteins (LDL) in the bloodstream, in addition to the impaired vasodilatory effects of cholesterol. However, current research on CVD has revealed a cascade of mechanisms involving a series of events that contribute to the progression of CVD. Although this has been elucidated and summarized in previous studies the detailed correlation between platelet aggregation and innate immunity that plays an important role in CVD progression has not been thoroughly summarized. Furthermore, immune cell subtypes also contribute to the progression of plaque formation in the subendothelial layer. Thrombus formation and the coagulation cascade also have a vital role in the progression of atherosclerosis. Hence, in this mini review we aim to elucidate, summarize, and propose the potent therapeutic effect of ginseng on CVD, mainly on platelet aggregation, plaque formation, and thrombus formation.
Collapse
|
7
|
Janus-Bell E, Yakusheva A, Scandola C, Receveur N, Ahmed UM, Mouriaux C, Bourdon C, Loubière C, Eckly A, Senis YA, Panteleev MA, Gachet C, Mangin PH. Characterization of the Role of Integrin α5β1 in Platelet Function, Hemostasis, and Experimental Thrombosis. Thromb Haemost 2021; 122:767-776. [PMID: 34598304 PMCID: PMC9197593 DOI: 10.1055/a-1659-6214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Objective
Integrins are key regulators of various platelet functions. The pathophysiological importance of most platelet integrins has been investigated, with the exception of α5β1, a receptor for fibronectin. The aim of this study was to characterize the role of α5β1 in megakaryopoiesis, platelet function, and to determine its importance in hemostasis and arterial thrombosis.
Approach and Results
We generated a mouse strain deficient for integrin α5β1 on megakaryocytes and platelets (PF4Cre-α5
−/−
). PF4Cre-α5
−/−
mice were viable, fertile, and presented no apparent signs of abnormality. Megakaryopoiesis appears unaltered as evidence by a normal megakaryocyte morphology and development, which is in agreement with a normal platelet count. Expression of the main platelet receptors and the response of PF4Cre-α5
−/−
platelets to a series of agonists were all completely normal. Adhesion and aggregation of PF4Cre-α5
−/−
platelets under shear flow on fibrinogen, laminin, or von Willebrand factor were unimpaired. In contrast, PF4Cre-α5
−/−
platelets displayed a marked decrease in adhesion, activation, and aggregation on fibrillar cellular fibronectin and collagen. PF4Cre-α5
−/−
mice presented no defect in a tail-bleeding time assay and no increase in inflammatory bleeding in a reverse passive Arthus model and a lipopolysaccharide pulmonary inflammation model. Finally, no defects were observed in three distinct experimental models of arterial thrombosis based on ferric chloride-induced injury of the carotid artery, mechanical injury of the abdominal aorta, or laser-induced injury of mesenteric vessels.
Conclusion
In summary, this study shows that platelet integrin α5β1 is a key receptor for fibrillar cellular fibronectin but is dispensable in hemostasis and arterial thrombosis.
Collapse
Affiliation(s)
- Emily Janus-Bell
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France
| | - Alexandra Yakusheva
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France.,Center for Theoretical Problems of Physicochemical Pharmacology, Cellular Hemostasis Lab, Moscow, Russia
| | - Cyril Scandola
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France
| | - Nicolas Receveur
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France
| | - Usman Muhammad Ahmed
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France
| | - Clarisse Mouriaux
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France
| | - Catherine Bourdon
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France
| | - Cécile Loubière
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France
| | - Anita Eckly
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France
| | - Yotis A Senis
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France
| | - Mikhail A Panteleev
- Center for Theoretical Problems of Physicochemical Pharmacology, Cellular Hemostasis Lab, Moscow, Russia
| | - Christian Gachet
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France
| | - Pierre H Mangin
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France
| |
Collapse
|
8
|
Tao DL, Tassi Yunga S, Williams CD, McCarty OJT. Aspirin and antiplatelet treatments in cancer. Blood 2021; 137:3201-11. [PMID: 33940597 DOI: 10.1182/blood.2019003977] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 08/03/2020] [Indexed: 02/07/2023] Open
Abstract
Platelets have been hypothesized to promote certain neoplastic malignancies; however, antiplatelet drugs are still not part of routine pharmacological cancer prevention and treatment protocols. Paracrine interactions between platelets and cancer cells have been implicated in potentiating the dissemination, survival within the circulation, and extravasation of cancer cells at distant sites of metastasis. Signals from platelets have also been suggested to confer epigenetic alterations, including upregulating oncoproteins in circulating tumor cells, and secretion of potent growth factors may play roles in promoting mitogenesis, angiogenesis, and metastatic outgrowth. Thrombocytosis remains a marker of poor prognosis in patients with solid tumors. Experimental data suggest that lowering of platelet count may reduce tumor growth and metastasis. On the basis of the mechanisms by which platelets could contribute to cancer growth and metastasis, it is conceivable that drugs reducing platelet count or platelet activation might attenuate cancer progression and improve outcomes. We will review select pharmacological approaches that inhibit platelets and may affect cancer development and propagation. We begin by presenting an overview of clinical cancer prevention and outcome studies with low-dose aspirin. We then review current nonclinical development of drugs targeted to platelet binding, activation, and count as potential mitigating agents in cancer.
Collapse
|
9
|
Douglass M, Hopkins S, Pandey R, Singha P, Norman M, Handa H. S-Nitrosoglutathione-Based Nitric Oxide-Releasing Nanofibers Exhibit Dual Antimicrobial and Antithrombotic Activity for Biomedical Applications. Macromol Biosci 2021; 21:e2000248. [PMID: 33021079 PMCID: PMC7855517 DOI: 10.1002/mabi.202000248] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/07/2020] [Indexed: 12/20/2022]
Abstract
The novel use of nanofibers as a physical barrier between blood and medical devices has allowed for modifiable, innovative surface coatings on devices ordinarily plagued by thrombosis, delayed healing, and chronic infection. In this study, the nitric oxide (NO) donor S-nitrosoglutathione (GSNO) is blended with the biodegradable polymers polyhydroxybutyrate (PHB) and polylactic acid (PLA) for the fabrication of hemocompatible, antibacterial nanofibers tailored for blood-contacting applications. Stress/strain behavior of different concentrations of PHB and PLA is recorded to optimize the mechanical properties of the nanofibers. Nanofibers incorporated with different concentrations of GSNO (10, 15, 20 wt%) are evaluated based on their NO-releasing kinetics. PLA/PHB + 20 wt% GSNO nanofibers display the greatest NO release over 72 h (0.4-1.5 × 10-10 mol mg-1 min-1 ). NO-releasing fibers successfully reduce viable adhered bacterial counts by ≈80% after 24 h of exposure to Staphylococcus aureus. NO-releasing nanofibers exposed to porcine plasma reduce platelet adhesion by 64.6% compared to control nanofibers. The nanofibers are found noncytotoxic (>95% viability) toward NIH/3T3 mouse fibroblasts, and 4',6-diamidino-2-phenylindole and phalloidin staining shows that fibroblasts cultured on NO-releasing fibers have improved cellular adhesion and functionality. Therefore, these novel NO-releasing nanofibers provide a safe antimicrobial and hemocompatible coating for blood-contacting medical devices.
Collapse
Affiliation(s)
- Megan Douglass
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, USA
| | - Sean Hopkins
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, USA
| | - Rashmi Pandey
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, USA
| | - Priya Singha
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, USA
| | - Megan Norman
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, USA
| | - Hitesh Handa
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, USA
| |
Collapse
|
10
|
Affiliation(s)
- Anh T P Ngo
- Departments of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA
| | - Maaike Jongen
- Departments of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA
| | - Joseph J Shatzel
- Departments of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA.,Departments of Hematology-Oncology, Oregon Health & Science University, Portland, OR, USA
| | - Owen J T McCarty
- Departments of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA.,Departments of Hematology-Oncology, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
11
|
Pike JA, Simms VA, Smith CW, Morgan NV, Khan AO, Poulter NS, Styles IB, Thomas SG. An adaptable analysis workflow for characterization of platelet spreading and morphology. Platelets 2020; 32:54-58. [PMID: 32321340 PMCID: PMC8802896 DOI: 10.1080/09537104.2020.1748588] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The assessment of platelet spreading through light microscopy, and the subsequent quantification of parameters such as surface area and circularity, is a key assay for many platelet biologists. Here we present an analysis workflow which robustly segments individual platelets to facilitate the analysis of large numbers of cells while minimizing user bias. Image segmentation is performed by interactive learning and touching platelets are separated with an efficient semi-automated protocol. We also use machine learning methods to robustly automate the classification of platelets into different subtypes. These adaptable and reproducible workflows are made freely available and are implemented using the open-source software KNIME and ilastik.
Collapse
Affiliation(s)
- Jeremy A Pike
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham , Midlands, UK.,Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham , Birmingham, UK
| | - Victoria A Simms
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham , Birmingham, UK
| | - Christopher W Smith
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham , Birmingham, UK
| | - Neil V Morgan
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham , Birmingham, UK
| | - Abdullah O Khan
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham , Birmingham, UK
| | - Natalie S Poulter
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham , Midlands, UK.,Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham , Birmingham, UK
| | - Iain B Styles
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham , Midlands, UK.,School of Computer Science, University of Birmingham , Birmingham, UK
| | - Steven G Thomas
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham , Midlands, UK.,Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham , Birmingham, UK
| |
Collapse
|
12
|
Ward Y, Lake R, Faraji F, Sperger J, Martin P, Gilliard C, Ku KP, Rodems T, Niles D, Tillman H, Yin J, Hunter K, Sowalsky AG, Lang J, Kelly K. Platelets Promote Metastasis via Binding Tumor CD97 Leading to Bidirectional Signaling that Coordinates Transendothelial Migration. Cell Rep 2019; 23:808-822. [PMID: 29669286 DOI: 10.1016/j.celrep.2018.03.092] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 02/16/2018] [Accepted: 03/20/2018] [Indexed: 02/02/2023] Open
Abstract
Tumor cells initiate platelet activation leading to the secretion of bioactive molecules, which promote metastasis. Platelet receptors on tumors have not been well-characterized, resulting in a critical gap in knowledge concerning platelet-promoted metastasis. We identify a direct interaction between platelets and tumor CD97 that stimulates rapid bidirectional signaling. CD97, an adhesion G protein-coupled receptor (GPCR), is an overexpressed tumor antigen in several cancer types. Purified CD97 extracellular domain or tumor cell-associated CD97 stimulated platelet activation. CD97-initiated platelet activation led to granule secretion, including the release of ATP, a mediator of endothelial junction disruption. Lysophosphatidic acid (LPA) derived from platelets induced tumor invasiveness via proximal CD97-LPAR heterodimer signaling, coupling coincident tumor cell migration and vascular permeability to promote transendothelial migration. Consistent with this, CD97 was necessary for tumor cell-induced vascular permeability in vivo and metastasis formation in preclinical models. These findings support targeted blockade of tumor CD97 as an approach to ameliorate metastatic spread.
Collapse
Affiliation(s)
- Yvona Ward
- Laboratory of Genitourinary Cancer Pathogenesis, NCI, Bethesda, MD 20892, USA
| | - Ross Lake
- Laboratory of Genitourinary Cancer Pathogenesis, NCI, Bethesda, MD 20892, USA
| | - Farhoud Faraji
- Laboratory of Cancer Biology and Genetics, NCI, Bethesda, MD 20892, USA
| | - Jamie Sperger
- Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Philip Martin
- Center for Advanced Preclinical Research, NCI, Frederick, MD 21702, USA
| | - Cameron Gilliard
- Molecular Biology and Genetics Section, NIDDK, Bethesda, MD 20892, USA
| | - Kimberly P Ku
- Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Tamara Rodems
- Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - David Niles
- Depatment of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Heather Tillman
- Laboratory of Genitourinary Cancer Pathogenesis, NCI, Bethesda, MD 20892, USA
| | - JuanJuan Yin
- Laboratory of Genitourinary Cancer Pathogenesis, NCI, Bethesda, MD 20892, USA
| | - Kent Hunter
- Laboratory of Cancer Biology and Genetics, NCI, Bethesda, MD 20892, USA
| | - Adam G Sowalsky
- Laboratory of Genitourinary Cancer Pathogenesis, NCI, Bethesda, MD 20892, USA
| | - Joshua Lang
- Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Kathleen Kelly
- Laboratory of Genitourinary Cancer Pathogenesis, NCI, Bethesda, MD 20892, USA.
| |
Collapse
|
13
|
Abstract
The vasculature is a dynamic environment in which blood platelets constantly survey the endothelium for sites of vessel damage. The formation of a mechanically coherent hemostatic plug to prevent blood loss relies on a coordinated series of ligand-receptor interactions governing the recruitment, activation, and aggregation of platelets. The physical biology of each step is distinct in that the recruitment of platelets depends on the mechanosensing of the platelet receptor glycoprotein Ib for the adhesive protein von Willebrand factor, whereas platelet activation and aggregation are responsive to the mechanical forces sensed at adhesive junctions between platelets and at the platelet-matrix interface. Herein we take a biophysical perspective to discuss the current understanding of platelet mechanotransduction as well as the measurement techniques used to quantify the physical biology of platelets in the context of thrombus formation under flow.
Collapse
Affiliation(s)
- Caroline E Hansen
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, Georgia 30332, USA; .,Wallace H. Coulter Department of Biomedical Engineering and Institute for Electronics and Nanotechnology, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| | - Yongzhi Qiu
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, Georgia 30332, USA; .,Wallace H. Coulter Department of Biomedical Engineering and Institute for Electronics and Nanotechnology, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| | - Owen J T McCarty
- Department of Cell, Developmental, and Cancer Biology, Oregon Health & Science University, Portland, Oregon 97239, USA.,Division of Hematology and Medical Oncology and Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Wilbur A Lam
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, Georgia 30332, USA; .,Wallace H. Coulter Department of Biomedical Engineering and Institute for Electronics and Nanotechnology, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| |
Collapse
|
14
|
Chen Y, Ju LA, Zhou F, Liao J, Xue L, Su QP, Jin D, Yuan Y, Lu H, Jackson SP, Zhu C. An integrin α IIbβ 3 intermediate affinity state mediates biomechanical platelet aggregation. Nat Mater 2019; 18:760-769. [PMID: 30911119 PMCID: PMC6586518 DOI: 10.1038/s41563-019-0323-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 02/19/2019] [Indexed: 05/20/2023]
Abstract
Integrins are membrane receptors that mediate cell adhesion and mechanosensing. The structure-function relationship of integrins remains incompletely understood, despite the extensive studies carried out because of its importance to basic cell biology and translational medicine. Using a fluorescence dual biomembrane force probe, microfluidics and cone-and-plate rheometry, we applied precisely controlled mechanical stimulations to platelets and identified an intermediate state of integrin αIIbβ3 that is characterized by an ectodomain conformation, ligand affinity and bond lifetimes that are all intermediate between the well-known inactive and active states. This intermediate state is induced by ligand engagement of glycoprotein (GP) Ibα via a mechanosignalling pathway and potentiates the outside-in mechanosignalling of αIIbβ3 for further transition to the active state during integrin mechanical affinity maturation. Our work reveals distinct αIIbβ3 state transitions in response to biomechanical and biochemical stimuli, and identifies a role for the αIIbβ3 intermediate state in promoting biomechanical platelet aggregation.
Collapse
Affiliation(s)
- Yunfeng Chen
- Woodruff School of Mechanical Engineering and Georgia Institute of Technology, Atlanta, GA, USA
- Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Lining Arnold Ju
- Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
- Heart Research Institute, The University of Sydney, Camperdown, New South Wales, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Camperdown, New South Wales, Australia
| | - Fangyuan Zhou
- Woodruff School of Mechanical Engineering and Georgia Institute of Technology, Atlanta, GA, USA
- Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Jiexi Liao
- Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Lingzhou Xue
- Department of Statistics, Pennsylvania State University, University Park, PA, USA
| | - Qian Peter Su
- Institute for Biomedical Materials and Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Dayong Jin
- Institute for Biomedical Materials and Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Yuping Yuan
- Heart Research Institute, The University of Sydney, Camperdown, New South Wales, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
| | - Hang Lu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Shaun P Jackson
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, The Scripps Research Institute, La Jolla, CA, USA.
- Heart Research Institute, The University of Sydney, Camperdown, New South Wales, Australia.
- Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia.
| | - Cheng Zhu
- Woodruff School of Mechanical Engineering and Georgia Institute of Technology, Atlanta, GA, USA.
- Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, USA.
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
- Heart Research Institute, The University of Sydney, Camperdown, New South Wales, Australia.
| |
Collapse
|
15
|
Abstract
Thrombus formation is dependent on the interaction of platelets, leukocytes and endothelial cells as well as proteins of the coagulation cascade. This interaction is tightly controlled by phospho-regulated pathways involving protein kinase CK2. A growing number of studies have demonstrated an important role of this kinase in the regulation of primary and secondary hemostasis. Inhibition of CK2 downregulates the expression of important adhesion molecules on platelets and endothelial cells, such as glycoprotein (GP)IIb/IIIa, P-selectin, von Willebrand factor and vascular cell adhesion molecule. Moreover, the reduced CK2-dependent phosphorylation of different coagulation factors prevents the conversion of fibrinogen to fibrin. Targeting these mechanisms may open the door for the development of novel anti-thrombotic therapies.
Collapse
Affiliation(s)
- Emmanuel Ampofo
- a Institute for Clinical & Experimental Surgery , Saarland University , Homburg/Saar , Germany
| | - Beate M Schmitt
- a Institute for Clinical & Experimental Surgery , Saarland University , Homburg/Saar , Germany
| | - Matthias W Laschke
- a Institute for Clinical & Experimental Surgery , Saarland University , Homburg/Saar , Germany
| | - Michael D Menger
- a Institute for Clinical & Experimental Surgery , Saarland University , Homburg/Saar , Germany
| |
Collapse
|
16
|
Lickert S, Sorrentino S, Studt JD, Medalia O, Vogel V, Schoen I. Morphometric analysis of spread platelets identifies integrin α IIbβ 3-specific contractile phenotype. Sci Rep 2018; 8:5428. [PMID: 29615672 DOI: 10.1038/s41598-018-23684-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 03/13/2018] [Indexed: 11/17/2022] Open
Abstract
Haemostatic platelet function is intimately linked to cellular mechanics and cytoskeletal morphology. How cytoskeletal reorganizations give rise to a highly contractile phenotype that is necessary for clot contraction remains poorly understood. To elucidate this process in vitro, we developed a morphometric screen to quantify the spatial organization of actin fibres and vinculin adhesion sites in single spread platelets. Platelets from healthy donors predominantly adopted a bipolar morphology on fibrinogen and fibronectin, whereas distinguishable, more isotropic phenotypes on collagen type I or laminin. Specific integrin αIIbβ3 inhibitors induced an isotropic cytoskeletal organization in a dose-dependent manner. The same trend was observed with decreasing matrix stiffness. Circular F-actin arrangements in platelets from a patient with type II Glanzmann thrombasthenia (GT) were consistent with the residual activity of a small number of αIIbβ3 integrins. Cytoskeletal morphologies in vitro thus inform about platelet adhesion receptor identity and functionality, and integrin αIIbβ3 mechanotransduction fundamentally determines the adoption of a bipolar phenotype associated with contraction. Super-resolution microscopy and electron microscopies further confirmed the stress fibre-like contractile actin architecture. For the first time, our assay allows the unbiased and quantitative assessment of platelet morphologies and could help to identify defective platelet behaviour contributing to elusive bleeding phenotypes.
Collapse
|
17
|
Abstract
Platelets serve as "first responders" during normal wounding and homeostasis. Arising from bone marrow stem cell lineage megakaryocytes, anucleate platelets can influence inflammation and immune regulation. Biophysically, platelets are optimized due to size and discoid morphology to distribute near vessel walls, monitor vascular integrity, and initiate quick responses to vascular lesions. Adhesion receptors linked to a highly reactive filopodia-generating cytoskeleton maximizes their vascular surface contact allowing rapid response capabilities. Functionally, platelets normally initiate rapid clotting, vasoconstriction, inflammation, and wound biology that leads to sterilization, tissue repair, and resolution. Platelets also are among the first to sense, phagocytize, decorate, or react to pathogens in the circulation. These platelet first responder properties are commandeered during chronic inflammation, cancer progression, and metastasis. Leaky or inflammatory reaction blood vessel genesis during carcinogenesis provides opportunities for platelet invasion into tumors. Cancer is thought of as a non-healing or chronic wound that can be actively aided by platelet mitogenic properties to stimulate tumor growth. This growth ultimately outstrips circulatory support leads to angiogenesis and intravasation of tumor cells into the blood stream. Circulating tumor cells reengage additional platelets, which facilitates tumor cell adhesion, arrest and extravasation, and metastasis. This process, along with the hypercoagulable states associated with malignancy, is amplified by IL6 production in tumors that stimulate liver thrombopoietin production and elevates circulating platelet numbers by thrombopoiesis in the bone marrow. These complex interactions and the "first responder" role of platelets during diverse physiologic stresses provide a useful therapeutic target that deserves further exploration.
Collapse
Affiliation(s)
- David G Menter
- Department of Gastrointestinal Medical Oncology, M. D. Anderson Cancer Center, Room#: FC10.3004, 1515 Holcombe Boulevard--Unit 0426, Houston, TX, 77030, USA.
| | - Scott Kopetz
- Department of Gastrointestinal Medical Oncology, M. D. Anderson Cancer Center, Room#: FC10.3004, 1515 Holcombe Boulevard--Unit 0426, Houston, TX, 77030, USA
| | - Ernest Hawk
- Office of the Vice President Cancer Prevention & Population Science, M. D. Anderson Cancer Center, Unit 1370, 1515 Holcombe Boulevard, Houston, TX, 77054, USA
| | - Anil K Sood
- Gynocologic Oncology & Reproductive Medicine, M. D. Anderson Cancer Center, Unit 1362, 1515 Holcombe Boulevard, Houston, TX, 77054, USA.,Department of Cancer Biology, M. D. Anderson Cancer Center, Unit 1362, 1515 Holcombe Boulevard, Houston, TX, 77054, USA.,Center for RNA Interference and Non-Coding RNA The University of Texas MD Anderson Cancer Center, Houston, TX, 77054, USA
| | - Jonathan M Loree
- Department of Gastrointestinal Medical Oncology, M. D. Anderson Cancer Center, Room#: FC10.3004, 1515 Holcombe Boulevard--Unit 0426, Houston, TX, 77030, USA
| | - Paolo Gresele
- Department of Medicine, Section of Internal and Cardiovascular Medicine, University of Perugia, Via E. Dal Pozzo, 06126, Perugia, Italy
| | - Kenneth V Honn
- Bioactive Lipids Research Program, Department of Pathology, Wayne State University, 431 Chemistry Bldg, 5101 Cass Avenue, Detroit, MI, 48202, USA.,Department of Pathology, Wayne State University, 431 Chemistry Bldg, 5101 Cass Avenue, Detroit, MI, 48202, USA.,Cancer Biology Division, Wayne State University School of Medicine, 431 Chemistry Bldg, 5101 Cass Avenue, Detroit, MI, 48202, USA
| |
Collapse
|
18
|
Ngo ATP, McCarty OJT, Aslan JE. TRPing out Platelet Calcium: TRPM7 (Transient Receptor Potential Melastatin-Like 7) Modulates Calcium Mobilization and Platelet Function via Phospholipase C Interactions. Arterioscler Thromb Vasc Biol 2018; 38:285-286. [PMID: 29367228 DOI: 10.1161/atvbaha.117.310493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Anh T P Ngo
- From the Department of Biomedical Engineering (A.T.P.N., O.J.T.M.), Department of Biochemistry and Molecular Biology (J.E.A.), and Knight Cardiovascular Institute (J.E.A.), School of Medicine, Oregon Health & Science University, Portland
| | - Owen J T McCarty
- From the Department of Biomedical Engineering (A.T.P.N., O.J.T.M.), Department of Biochemistry and Molecular Biology (J.E.A.), and Knight Cardiovascular Institute (J.E.A.), School of Medicine, Oregon Health & Science University, Portland
| | - Joseph E Aslan
- From the Department of Biomedical Engineering (A.T.P.N., O.J.T.M.), Department of Biochemistry and Molecular Biology (J.E.A.), and Knight Cardiovascular Institute (J.E.A.), School of Medicine, Oregon Health & Science University, Portland.
| |
Collapse
|
19
|
Rossi E, Pericacho M, Bachelot-Loza C, Pidard D, Gaussem P, Poirault-Chassac S, Blanco FJ, Langa C, González-Manchón C, Novoa JML, Smadja DM, Bernabeu C. Human endoglin as a potential new partner involved in platelet-endothelium interactions. Cell Mol Life Sci 2018; 75:1269-84. [PMID: 29080903 DOI: 10.1007/s00018-017-2694-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 10/20/2017] [Accepted: 10/24/2017] [Indexed: 11/20/2022]
Abstract
Complex interactions between platelets and activated endothelium occur during the thrombo-inflammatory reaction at sites of vascular injuries and during vascular hemostasis. The endothelial receptor endoglin is involved in inflammation through integrin-mediated leukocyte adhesion and transmigration; and heterozygous mutations in the endoglin gene cause hereditary hemorrhagic telangiectasia type 1. This vascular disease is characterized by a bleeding tendency that is postulated to be a consequence of telangiectasia fragility rather than a platelet defect, since platelets display normal functions in vitro in this condition. Here, we hypothesize that endoglin may act as an adhesion molecule involved in the interaction between endothelial cells and platelets through integrin recognition. We find that the extracellular domain of human endoglin promotes specific platelet adhesion under static conditions and confers resistance of adherent platelets to detachment upon exposure to flow. Also, platelets adhere to confluent endothelial cells in an endoglin-mediated process. Remarkably, Chinese hamster ovary cells ectopically expressing the human αIIbβ3 integrin acquire the capacity to adhere to myoblast transfectants expressing human endoglin, whereas platelets from Glanzmann’s thrombasthenia patients lacking the αIIbβ3 integrin are defective for endoglin-dependent adhesion to endothelial cells. Furthermore, the bleeding time, but not the prothrombin time, is significantly prolonged in endoglin-haplodeficient (Eng+/−) mice compared to Eng+/+ animals. These results suggest a new role for endoglin in αIIbβ3 integrin-mediated adhesion of platelets to the endothelium, and may provide a better understanding on the basic cellular mechanisms involved in hemostasis and thrombo-inflammatory events.
Collapse
|
20
|
Abstract
PURPOSE OF REVIEW This review describes the essential roles of platelets in neutrophil recruitment from the bloodstream into inflamed and infected tissues, with a focus on recent findings. RECENT FINDINGS Platelets are required for the recruitment of neutrophils to sites of inflammation and infection. They fulfil this role largely by enabling contacts of circulating neutrophils with the inflamed blood vessel wall prior to extravasation. Platelets promote both early stages of neutrophil recruitment (tethering, rolling, arrest, firm adhesion) and - as recent work has demonstrated - later stages (intravascular crawling and diapedesis). Recent studies have also begun to identify platelet-signaling pathways that can elicit the underlying interactions between platelets, neutrophils and vascular endothelial cells without stimulating concomitant platelet aggregation and thrombus formation. These pathways include Rho-guanine-nucleotide binding proteins and Rho-guanine-nucleotide exchange factors. SUMMARY Recent findings have contributed to our burgeoning understanding of the platelet-dependent mechanisms that control neutrophil recruitment to sites of inflammation and have opened up new avenues of research aimed at increasing our knowledge of these mechanisms further. These insights might lead to the development of novel anti-inflammatory drugs that will be useful in a wide range of inflammatory diseases without causing immunodeficiency.
Collapse
|
21
|
Lavergne M, Janus-Bell E, Schaff M, Gachet C, Mangin PH. Platelet Integrins in Tumor Metastasis: Do They Represent a Therapeutic Target? Cancers (Basel). 2017;9. [PMID: 28956830 PMCID: PMC5664072 DOI: 10.3390/cancers9100133] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 09/22/2017] [Accepted: 09/25/2017] [Indexed: 12/14/2022] Open
Abstract
Platelets are small anucleated cell fragments that ensure the arrest of bleeding after a vessel wall injury. They are also involved in non-hemostatic function such as development, immunity, inflammation, and in the hematogeneous phase of metastasis. While the role of platelets in tumor metastasis has been recognized for 60 years, the molecular mechanism underlying this process remains largely unclear. Platelets physically and functionally interact with various tumor cells through surface receptors including integrins. Platelets express five integrins at their surface, namely α2β1, α5β1, α6β1, αvβ3, and αIIbβ3, which bind preferentially to collagen, fibronectin, laminin, vitronectin, and fibrinogen, respectively. The main role of platelet integrins is to ensure platelet adhesion and aggregation at sites of vascular injury. Two of these, α6β1 and αIIbβ3, were proposed to participate in platelet–tumor cell interaction and in tumor metastasis. It has also been reported that pharmacological agents targeting both integrins efficiently reduce experimental metastasis, suggesting that platelet integrins may represent new anti-metastatic targets. This review focuses on the role of platelet integrins in tumor metastasis and discusses whether these receptors may represent new potential targets for novel anti-metastatic approaches.
Collapse
|
22
|
Huber B, Engelhardt S, Meyer W, Krüger H, Wenz A, Schönhaar V, Tovar GEM, Kluger PJ, Borchers K. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization. J Funct Biomater 2016; 7:E11. [PMID: 27104576 PMCID: PMC4932468 DOI: 10.3390/jfb7020011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 03/18/2016] [Accepted: 04/08/2016] [Indexed: 12/16/2022] Open
Abstract
Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA) for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of approximately 100 µm or 200 µm. We established a rinsing protocol to remove remaining cytotoxic substances from the photo-cured PA and applied thio-modified heparin and RGDC-peptides to functionalize the PA surface for enhanced endothelial cell adhesion. A rotating seeding procedure was introduced to ensure homogenous endothelial monolayer formation at the inner luminal tube wall. We showed that endothelial cells stayed viable and adherent and aligned along the medium flow under fluid-flow conditions comparable to native capillaries. The combined technology approach comprising of freeform additive manufacturing (AM), biomimetic design, cytocompatible materials which are applicable to AM, and biofunctionalization of AM constructs has been introduced as BioRap(®) technology by the authors.
Collapse
Affiliation(s)
- Birgit Huber
- Institute of Interfacial Process Engineering and Plasma Technology IGVP, University of Stuttgart, Stuttgart 70569, Germany.
| | - Sascha Engelhardt
- Rheinisch-Westfälische Technische Hochschule Aachen, RWTH Aachen, Aachen 52074, Germany.
| | - Wolfdietrich Meyer
- Fraunhofer Institute for Applied Polymer Research IAP, Potsdam 14476, Germany.
| | - Hartmut Krüger
- Fraunhofer Institute for Applied Polymer Research IAP, Potsdam 14476, Germany.
| | - Annika Wenz
- Institute of Interfacial Process Engineering and Plasma Technology IGVP, University of Stuttgart, Stuttgart 70569, Germany.
| | - Veronika Schönhaar
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart 70569, Germany.
| | - Günter E M Tovar
- Institute of Interfacial Process Engineering and Plasma Technology IGVP, University of Stuttgart, Stuttgart 70569, Germany.
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart 70569, Germany.
| | - Petra J Kluger
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart 70569, Germany.
- Process Analysis & Technology (PA&T), Reutlingen University, Reutlingen 72762, Germany.
| | - Kirsten Borchers
- Institute of Interfacial Process Engineering and Plasma Technology IGVP, University of Stuttgart, Stuttgart 70569, Germany.
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart 70569, Germany.
| |
Collapse
|
23
|
Maurer E, Schaff M, Receveur N, Bourdon C, Mercier L, Nieswandt B, Dubois C, Jandrot-Perrus M, Goetz JG, Lanza F, Gachet C, Mangin PH. Fibrillar cellular fibronectin supports efficient platelet aggregation and procoagulant activity. Thromb Haemost 2015; 114:1175-88. [PMID: 26245230 DOI: 10.1160/th14-11-0958] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 06/21/2015] [Indexed: 01/07/2023]
Abstract
The ability of cellular fibronectin, found in the vessel wall in a fibrillar conformation, to regulate platelet functions and trigger thrombus formation remains largely unknown. In this study, we evaluated how parietal cellular fibronectin can modulate platelet responses under flow conditions. A fibrillar network was formed by mechanically stretching immobilised dimeric cellular fibronectin. Perfusion of anticoagulated whole blood over this surface resulted in efficient platelet adhesion and thrombus growth. The initial steps of platelet adhesion and activation, as evidenced by filopodia extension and an increase in intracellular calcium levels (419 ± 29 nmol/l), were dependent on integrins α5β1 and αIIbβ3. Subsequent thrombus growth was mediated by these integrins together with the GPIb-V-IX complex, GPVI and Toll-like receptor 4. The involvement of Toll-like receptor 4 could be conveyed via its binding to the EDA region of cellular fibronectin. Upon thrombus formation, the platelets became procoagulant and generated fibrin as revealed by video-microscopy. This work provides evidence that fibrillar cellular fibronectin is a strong thrombogenic surface which supports efficient platelet adhesion, activation, aggregation and procoagulant activity through the interplay of a series of receptors including integrins α5β1 and αIIbβ3, the GPIb-V-IX complex, GPVI and Toll-like receptor 4.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Pierre H Mangin
- Pierre H. Mangin, UMR_S949, INSERM, Etablissement Français du Sang-Alsace (EFS-Alsace), 10, rue Spielmann, BP 36, F-67065 Strasbourg Cedex, France, Tel.: +33 3 88 21 25 25, Fax: +33 3 88 21 25 21, E-mail:
| |
Collapse
|
24
|
Huynh KC, Stoldt VR, Scharf RE. Contribution of distinct platelet integrins to binding, unfolding, and assembly of fibronectin. Biol Chem 2014; 394:1485-93. [PMID: 23929882 DOI: 10.1515/hsz-2013-0182] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 08/06/2013] [Indexed: 11/15/2022]
Abstract
Fibronectin (FN) fibrillogenesis depends on the binding of FN to cellular receptors and subsequent unfolding of bound FN. Integrins αIIbβ3, αvβ3, and α5β1 are known to assemble FN fibrils on platelets. In our study, we examined the contribution of these integrins to FN binding, unfolding, and assembly on platelets in suspension and adherent platelets in the presence or absence of agonists. Phorbol 12-myristate 13-acetate (PMA), but not adenosine diphosphate (ADP), induced binding of FN to platelets in suspension. In contrast, adherent platelets were able to deposit FN on their surfaces in the absence of agonists. β3 integrins had a major impact on the interaction of FN on platelets. αvβ3 showed a similar contribution to the binding of FN as αIIbβ3 on PMA-stimulated platelets in suspension but had a lesser contribution to unfolding and deposition of FN on adherent platelets. α5β1 also participated in the interaction of FN with platelets by mediating the unfolding and assembly of FN, but to a lesser extent than β3 integrins. None of the distinct antibodies directed against one of the three integrins caused a complete inhibition of binding, unfolding, and assembly of FN by platelets. Thus, it is likely that αIIbβ3, αvβ3, and α5β1 or another still unknown receptor can be substituted.
Collapse
|
25
|
Hobbs CM, Manning H, Bennett C, Vasquez L, Severin S, Brain L, Mazharian A, Guerrero JA, Li J, Soranzo N, Green AR, Watson SP, Ghevaert C. JAK2V617F leads to intrinsic changes in platelet formation and reactivity in a knock-in mouse model of essential thrombocythemia. Blood. 2013;122:3787-3797. [PMID: 24085768 DOI: 10.1182/blood-2013-06-501452] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The principal morbidity and mortality in patients with essential thrombocythemia (ET) and polycythemia rubra vera (PV) stems from thrombotic events. Most patients with ET/PV harbor a JAK2V617F mutation, but its role in the thrombotic diathesis remains obscure. Platelet function studies in patients are difficult to interpret because of interindividual heterogeneity, reflecting variations in the proportion of platelets derived from the malignant clone, differences in the presence of additional mutations, and the effects of medical treatments. To circumvent these issues, we have studied a JAK2V617F knock-in mouse model of ET in which all megakaryocytes and platelets express JAK2V617F at a physiological level, equivalent to that present in human ET patients. We show that, in addition to increased differentiation, JAK2V617F-positive megakaryocytes display greater migratory ability and proplatelet formation. We demonstrate in a range of assays that platelet reactivity to agonists is enhanced, with a concomitant increase in platelet aggregation in vitro and a reduced duration of bleeding in vivo. These data suggest that JAK2V617F leads to intrinsic changes in both megakaryocyte and platelet biology beyond an increase in cell number. In support of this hypothesis, we identify multiple differentially expressed genes in JAK2V617F megakaryocytes that may underlie the observed biological differences.
Collapse
|
26
|
Abstract
The Rho family of GTP binding proteins, also commonly referred to as the Rho GTPases, are master regulators of the platelet cytoskeleton and platelet function. These low-molecular-weight or 'small' GTPases act as signaling switches in the spatial and temporal transduction, and amplification of signals from platelet cell surface receptors to the intracellular signaling pathways that drive platelet function. The Rho GTPase family members RhoA, Cdc42 and Rac1 have emerged as key regulators in the dynamics of the actin cytoskeleton in platelets and play key roles in platelet aggregation, secretion, spreading and thrombus formation. Rho GTPase regulators, including GEFs and GAPs and downstream effectors, such as the WASPs, formins and PAKs, may also regulate platelet activation and function. In this review, we provide an overview of Rho GTPase signaling in platelet physiology. Previous studies of Rho GTPases and platelets have had a shared history, as platelets have served as an ideal, non-transformed cellular model to characterize Rho function. Likewise, recent studies of the cell biology of Rho GTPase family members have helped to build an understanding of the molecular regulation of platelet function and will continue to do so through the further characterization of Rho GTPases as well as Rho GAPs, GEFs, RhoGDIs and Rho effectors in actin reorganization and other Rho-driven cellular processes.
Collapse
Affiliation(s)
- J E Aslan
- Department of Biomedical Engineering and Cell & Developmental Biology, School of Medicine, Oregon Health & Science University, Portland, OR 97239, USA.
| | | |
Collapse
|
27
|
Hughes CE, Sinha U, Pandey A, Eble JA, O'Callaghan CA, Watson SP. Critical Role for an acidic amino acid region in platelet signaling by the HemITAM (hemi-immunoreceptor tyrosine-based activation motif) containing receptor CLEC-2 (C-type lectin receptor-2). J Biol Chem 2012; 288:5127-35. [PMID: 23264619 PMCID: PMC3576117 DOI: 10.1074/jbc.m112.411462] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
CLEC-2 is a member of new family of C-type lectin receptors characterized by a cytosolic YXXL downstream of three acidic amino acids in a sequence known as a hemITAM (hemi-immunoreceptor tyrosine-based activation motif). Dimerization of two phosphorylated CLEC-2 molecules leads to recruitment of the tyrosine kinase Syk via its tandem SH2 domains and initiation of a downstream signaling cascade. Using Syk-deficient and Zap-70-deficient cell lines we show that hemITAM signaling is restricted to Syk and that the upstream triacidic amino acid sequence is required for signaling. Using surface plasmon resonance and phosphorylation studies, we demonstrate that the triacidic amino acids are required for phosphorylation of the YXXL. These results further emphasize the distinct nature of the proximal events in signaling by hemITAM relative to ITAM receptors.
Collapse
Affiliation(s)
- Craig E Hughes
- Centre for Cardiovascular Sciences, Institute for Biomedical Research, The College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
| | | | | | | | | | | |
Collapse
|
28
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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
| |
Collapse
|
29
|
Van de Walle AB, Fontenot J, Spain TG, Brunski DB, Sanchez ES, Keay JC, Curtis ME, Johnson MB, Snyder TA, Schmidtke DW. The role of fibrinogen spacing and patch size on platelet adhesion under flow. Acta Biomater 2012; 8:4080-91. [PMID: 22820307 DOI: 10.1016/j.actbio.2012.07.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2012] [Revised: 06/29/2012] [Accepted: 07/12/2012] [Indexed: 01/05/2023]
Abstract
Platelet adhesion to the vessel wall during vascular injury is mediated by platelet glycoproteins binding to their respective ligands on the vascular wall. In this study we investigated the roles that ligand patch spacing and size play in regulating platelet interactions with fibrinogen under hemodynamic flow conditions. To regulate the size and distance between patches of fibrinogen we developed a photolithography-based technique to fabricate patterns of proteins surrounded by a protein-repellant layer of poly(ethylene glycol). We demonstrate that when mepacrine labeled whole blood is perfused at a shear rate of 100 s ⁻¹ over substrates patterned with micron-sized wide lines of fibrinogen, platelets selectively adhere to the areas of patterned fibrinogen. Using fluorescent and scanning electron microscopy we demonstrate that the degree of platelet coverage (3-35%) and the ability of platelet aggregates to grow laterally are dependent upon the distance (6-30 μm) between parallel lines of fibrinogen. We also report on the effects of fibrinogen patch size on platelet adhesion by varying the size of the protein patch (2-20 μm) available for adhesion, demonstrating that the downstream length of the ligand patch is a critical parameter in platelet adhesion under flow. We expect that these results and protein patterning surfaces will be useful in understanding the spatial and temporal dynamics of platelet adhesion under physiologic flow, and in the development of novel platelet adhesion assays.
Collapse
|
30
|
Abstract
BACKGROUND AND OBJECTIVES Src family kinases (SFKs) play a critical role in initiating and propagating signals in platelets. The aims of this study were to quantitate SFK members present in platelets and to analyze their contribution to platelet regulation using glycoprotein VI (GPVI) and intregrin αIIbβ3, and in vivo. METHODS AND RESULTS Mouse platelets express four SFKs, Fgr, Fyn, Lyn and Src, with Lyn expressed at a considerably higher level than the others. Using mutant mouse models, we demonstrate that platelet activation by collagen-related peptide (CRP) is delayed and then potentiated in the absence of Lyn, but only marginally reduced in the absence of Fyn or Fgr, and unaltered in the absence of Src. Compound deletions of Lyn/Src or Fyn/Lyn, but not of Fyn/Src or Fgr/Lyn, exhibit a greater delay in activation relative to Lyn-deficient platelets. Fibrinogen-adherent platelets show reduced spreading in the absence of Src, potentiation in the absence of Lyn, but no change in the absence of Fyn or Fgr. In mice double-deficient in Lyn/Src or Fgr/Lyn, the inhibitory role of Lyn on spreading on fibrinogen is lost. Lyn is the major SFK-mediating platelet aggregation on collagen at arterial shear and its absence leads to a reduction in thrombus size in a laser injury model. CONCLUSION These results demonstrate that SFKs share individual and overlapping roles in regulating platelet activation, with Lyn having a dual role in regulating GPVI signaling and an inhibitory role downstream of αIIbβ3, which requires prior signaling through Src.
Collapse
Affiliation(s)
- S Séverin
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Spectre G, Zhu L, Ersoy M, Hjemdahl P, Savion N, Varon D, Li N. Platelets selectively enhance lymphocyte adhesion on subendothelial matrix under arterial flow conditions. Thromb Haemost 2012; 108:328-37. [PMID: 22688347 DOI: 10.1160/th12-02-0064] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 05/03/2012] [Indexed: 12/16/2022]
Abstract
Platelet adhesion at sites of cardiovascular injury may facilitate leukocyte deposition. We asked if and how platelets enhance lymphocyte adhesion on different subendothelial matrix protein (SEMP)-coated surface at arterial shear stress. Hirudinised whole blood was subjected to an arterial shear rate (500 s(-1)) in a Cone and Plate(let) analyser (CPA) for 5 minutes using plates coated with bovine serum albumin (BSA), collagen, fibrinogen, von Willebrand factor (vWF), or fibronectin. Platelet and lymphocyte adhesion were monitored by CPA and flow cytometry. Exposure of blood to collagen, fibrinogen, and vWF-coated surfaces induced platelet activation. The most marked effect was seen with collagen-coating, which markedly enhanced the adhesion of all lymphocyte subpopulations compared to BSA-coating. Fibrinogen-coating supported both T and NK cell adhesion, while vWF-coated surface only enhanced NK cell deposition. In contrast, fibronectin enhanced neither platelet activation nor lymphocyte adhesion. Moreover, platelets preferentially facilitated adhesion of large CD4(+) and CD8(+) T cells and NK cells, and of small B cells. Enhanced cell adhesion of larger lymphocytes was associated with elevated platelet conjugation and higher lymphocyte expression of PSGL-1, Mac-1, and CD40L. The enhancement of lymphocyte adhesion was totally platelet-dependent, and was abolished in platelet-depleted blood. Moreover, blockade of the platelet adhesion molecules P-selectin, GPIIb/IIIa, and CD40L attenuated platelet-dependent lymphocyte deposition. In conclusion, platelets support lymphocyte adhesion on SEMP-coated surfaces under arterial shear. The enhancement is selective for large T and NK cells and small B cells.
Collapse
Affiliation(s)
- Galia Spectre
- Department of Medicine-Solna, Clinical Pharmacology Unit, Karolinska Institute, Karolinska University Hospital-Solna, Stockholm, Sweden
| | | | | | | | | | | | | |
Collapse
|
32
|
Davies A, Lewis DJ, Watson SP, Thomas SG, Pikramenou Z. pH-controlled delivery of luminescent europium coated nanoparticles into platelets. Proc Natl Acad Sci U S A 2012; 109:1862-7. [PMID: 22308346 DOI: 10.1073/pnas.1112132109] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Water soluble, luminescent gold nanoparticles are delivered into human platelets via a rapid, pH-controlled mechanism using a pH low insertion peptide, pHLIP. The approach introduces cocoating of gold nanoparticles with a europium luminescent complex, EuL and the pHLIP peptide to give pHLIP•EuL•Au. The 13-nm diameter gold nanoparticles act as a scaffold for the attachment of both the luminescent probe and the peptide to target delivery. Their size allows delivery of approximately 640 lanthanide probes per nanoparticle to be internalized in human platelets, which are not susceptible to transfection or microinjection. The internalization of pHLIP•EuL•Au in platelets, which takes just minutes, was studied with a variety of imaging modalities including luminescence, confocal reflection, and transmission electron microscopy. The results show that pHLIP•EuL•Au only enters the platelets in low pH conditions, pH 6.5, mediated by the pHLIP translocation across the membrane, and not at pH 7.4. Luminescence microscopy images of the treated platelets show clearly the red luminescence signal from the europium probe and confocal reflection microscopy confirms the presence of the gold particles. Furthermore, transmission electron microscopy gives a detailed insight of the internalization and spatial localization of the gold nanoparticles in the platelets. Thus, we demonstrate the potential of the design to translocate multimodal nanoparticle probes into cells in a pH dependent manner.
Collapse
|
33
|
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.
Collapse
|
34
|
Hansen RR, Tipnis AA, White-Adams TC, Di Paola JA, Neeves KB. Characterization of collagen thin films for von Willebrand factor binding and platelet adhesion. Langmuir 2011; 27:13648-58. [PMID: 21967679 PMCID: PMC9028814 DOI: 10.1021/la2023727] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Von Willebrand factor (VWF) binding and platelet adhesion to subendothelial collagens are initial events in thrombus formation at sites of vascular injury. These events are often studied in vitro using flow assays designed to mimic vascular hemodynamics. Flow assays commonly employ collagen-functionalized substrates, but a lack of standardized methods of surface ligation limits their widespread use as a clinical diagnostic. Here, we report the use of collagen thin films (CTF) in flow assays. Thin films were grown on hydrophobic substrates from type I collagen solutions of increasing concentration (10, 100, and 1000 μg/mL). We found that the corresponding increase in fiber surface area determined the amount of VWF binding and platelet adhesion. The association rate constant (k(a)) of plasma VWF binding at a wall shear stress of 45 dyn/cm(2) was 0.3 × 10(5), 1.8 × 10(5), and 1.6 × 10(5) M(-1) s(-1) for CTF grown from 10, 100, and 1000 μg/mL solutions, respectively. We observed a 5-fold increase in VWF binding capacity with each 10-fold increase in collagen solution concentration. The association rates of Ser1731Thr and His1786Asp VWF mutants with collagen binding deficiencies were 9% and 22%, respectively, of wild-type rates. Using microfluidic devices for blood flow assays, we observed that CTF supported platelet adhesion at a wall shear rate of 1000 s(-1). CTF grown from 10 and 100 μg/mL solutions had variable levels of platelet surface coverage between multiple normal donors. However, CTF substrates grown from 1000 μg/mL solutions had reproducible surface coverage levels (74 ± 17%) between normal donors, and there was significantly diminished surface coverage from two type 1 von Willebrand disease patients (8.0% and 24%). These results demonstrate that collagen thin films are homogeneous and reproducible substrates that can measure dysfunctions in VWF binding and platelet adhesion under flow in a clinical microfluidic assay format.
Collapse
Affiliation(s)
- Ryan R. Hansen
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Alena A. Tipnis
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Tara C. White-Adams
- Department of Pediatrics, University of Colorado, Aurora, Colorado 80045, United States
| | - Jorge A. Di Paola
- Department of Pediatrics, University of Colorado, Aurora, Colorado 80045, United States
| | - Keith B. Neeves
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
- Department of Pediatrics, University of Colorado, Aurora, Colorado 80045, United States
- Corresponding Author: , Tel: 01-303-273-3191, Fax: 01-303-273-3730
| |
Collapse
|
35
|
Affiliation(s)
| | - Jeffrey J.D. Henry
- Department of Bioengineering, University of California, Berkeley, California 94720;
| |
Collapse
|
36
|
Itakura A, Aslan JE, Sinha S, White-Adams TC, Patel IA, Meza-Romero R, Vandenbark AA, Burrows GG, Offner H, McCarty OJ. Characterization of human platelet binding of recombinant T cell receptor ligand. J Neuroinflammation 2010; 7:75. [PMID: 21059245 DOI: 10.1186/1742-2094-7-75] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 11/08/2010] [Indexed: 11/10/2022] Open
Abstract
Background Recombinant T cell receptor ligands (RTLs) are bio-engineered molecules that may serve as novel therapeutic agents for the treatment of neuroinflammatory conditions such as multiple sclerosis (MS). RTLs contain membrane distal α1 plus β1 domains of class II major histocompatibility complex linked covalently to specific peptides that can be used to regulate T cell responses and inhibit experimental autoimmune encephalomyelitis (EAE). The mechanisms by which RTLs impede local recruitment and retention of inflammatory cells in the CNS, however, are not completely understood. Methods We have recently shown that RTLs bind strongly to B cells, macrophages, and dendritic cells, but not to T cells, in an antigenic-independent manner, raising the question whether peripheral blood cells express a distinct RTL-receptor. Our study was designed to characterize the molecular mechanisms by which RTLs bind human blood platelets, and the ability of RTL to modulate platelet function. Results Our data demonstrate that human blood platelets support binding of RTL. Immobilized RTL initiated platelet intracellular calcium mobilization and lamellipodia formation through a pathway dependent upon Src and PI3 kinases signaling. The presence of RTL in solution reduced platelet aggregation by collagen, while treatment of whole blood with RTL prolonged occlusive thrombus formation on collagen. Conclusions Platelets, well-known regulators of hemostasis and thrombosis, have been implicated in playing a major role in inflammation and immunity. This study provides the first evidence that blood platelets express a functional RTL-receptor with a putative role in modulating pathways of neuroinflammation.
Collapse
|
37
|
Hughes CE, Pollitt AY, Mori J, Eble JA, Tomlinson MG, Hartwig JH, O'Callaghan CA, Fütterer K, Watson SP. CLEC-2 activates Syk through dimerization. Blood 2010; 115:2947-55. [PMID: 20154219 DOI: 10.1182/blood-2009-08-237834] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The C-type lectin receptor CLEC-2 activates platelets through Src and Syk tyrosine kinases, leading to tyrosine phosphorylation of downstream adapter proteins and effector enzymes, including phospholipase-C gamma2. Signaling is initiated through phosphorylation of a single conserved tyrosine located in a YxxL sequence in the CLEC-2 cytosolic tail. The signaling pathway used by CLEC-2 shares many similarities with that used by receptors that have 1 or more copies of an immunoreceptor tyrosine-based activation motif, defined by the sequence Yxx(L/I)x(6-12)Yxx(L/I), in their cytosolic tails or associated receptor chains. Phosphorylation of the conserved immunoreceptor tyrosine-based activation motif tyrosines promotes Syk binding and activation through binding of the Syk tandem SH2 domains. In this report, we present evidence using peptide pull-down studies, surface plasmon resonance, quantitative Western blotting, tryptophan fluorescence measurements, and competition experiments that Syk activation by CLEC-2 is mediated by the cross-linking through the tandem SH2 domains with a stoichiometry of 2:1. In support of this model, cross-linking and electron microscopy demonstrate that CLEC-2 is present as a dimer in resting platelets and converted to larger complexes on activation. This is a unique mode of activation of Syk by a single YxxL-containing receptor.
Collapse
|
38
|
Kim HJ, Kim PK, Bae SM, Son HN, Thoudam DS, Kim JE, Lee BH, Park RW, Kim IS. Transforming growth factor-beta-induced protein (TGFBIp/beta ig-h3) activates platelets and promotes thrombogenesis. Blood 2009; 114:5206-15. [PMID: 19738031 DOI: 10.1182/blood-2009-03-212415] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transforming growth factor-beta-induced protein (TGFBIp)/beta ig-h3 is a 68-kDa extracellular matrix protein that is functionally associated with the adhesion, migration, proliferation, and differentiation of various cells. The presence of TGFBIp in platelets led us to study the role of this protein in the regulation of platelet functions. Upon activation, platelet TGFBIp was released and associated with the platelets. TGFBIp mediates not only the adhesion and spread of platelets but also activates them, resulting in phosphatidylserine exposure, alpha-granule secretion, and increased integrin affinity. The fasciclin 1 domains of TGFBIp are mainly responsible for the activation of platelets. TGFBIp promotes thrombus formation on type I fibrillar collagen under flow conditions in vitro and induces pulmonary embolism in mice. Moreover, transgenic mice, which have approximately a 1.7-fold greater blood TGFBIp concentration, are significantly more susceptible to collagen- and epinephrine-induced pulmonary embolism than wild-type mice. These results suggest that TGFBIp, a human platelet protein, plays important roles in platelet activation and thrombus formation. Our findings will increase our understanding of the novel mechanism of platelet activation, contributing to a better understanding of thrombotic pathways and the development of new antithrombotic therapies.
Collapse
|
39
|
Mousa SS, Davis FB, Davis PJ, Mousa SA. Human platelet aggregation and degranulation is induced in vitro by L-thyroxine, but not by 3,5,3'-triiodo-L-thyronine or diiodothyropropionic acid (DITPA). Clin Appl Thromb Hemost 2009; 16:288-93. [PMID: 19903697 DOI: 10.1177/1076029609348315] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The endogenous thyroid hormones L-thyroxine (T(4)) and 3,5,3'-triiodo-L-thyronine (T(3)) induce angiogenesis via an endothelial cell iodothyronine receptor on integrin alphaVbeta3. This receptor also exists on platelets. Diiodothyropropionic acid (DITPA) and GC-1, a noniodinated thyroid hormone analog, also induce angiogenesis. Here we examined the effects of iodothyronines (L-T(4) vs L-T(3)) and analogs DITPA and GC-1 on human platelet function. Subthreshold aggregation of platelets obtained from healthy human donors was induced with collagen. Platelet activation (proaggregation) and adenosine triphosphate (ATP) secretion (degranulation) induced by L-T( 4), L-T(4)-agarose, L-T(3), DITPA, or GC-1 were determined simultaneously. Platelet aggregation and ATP secretion induced by a subthreshold level of collagen were enhanced 3-fold by either L-T(4) or L-T( 4)-agarose (0.01 micromol/L) as compared to control, whereas, L-T( 3), DITPA, or GC-1 had no effect under the same conditions. The platelet proaggregatory and degranulation effects of L-T(4) were blocked by the alphavbeta3 antagonist XT199 (0.1 micromol/ L) and by tetraiodothyroacetic acid (tetrac; 0.1 micromol/L). Tetrac inhibits binding of thyroid hormone analogs to the receptor on alphavbeta3 and lacks thyromimetic activity at this site; thus, the proaggregatory action of L-T(4) likely involves the cell surface receptor on integrin alphavbeta3. The thyroid hormone receptor (TR) on human platelets but not endothelial cells distinguishes among iodothyronines, reflecting quantitative differences in integrin sites on endothelial cells and platelets or qualitative differences in the phospholipids/protein microenvironment of endothelial and platelet membranes that can affect integrin function. Additional studies in different populations with larger sample sizes are warranted to determine the impact of the current findings on clinical interventions.
Collapse
Affiliation(s)
- Shaymaa S Mousa
- Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Rensselaer, New York 12144, USA.
| | | | | | | |
Collapse
|
40
|
White-Adams TC, Berny MA, Tucker EI, Gertz JM, Gailani D, Urbanus RT, de Groot PG, Gruber A, McCarty OJT. Identification of coagulation factor XI as a ligand for platelet apolipoprotein E receptor 2 (ApoER2). Arterioscler Thromb Vasc Biol 2009; 29:1602-7. [PMID: 19661487 DOI: 10.1161/atvbaha.109.187393] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Factor XI (FXI) promotes hemostasis and thrombosis through enhancement of thrombin generation and has been shown to play a critical role in the formation of occlusive thrombi in arterial injury models. The aim of this study was to investigate the mechanisms governing interactions between FXI and platelets. METHODS AND RESULTS Platelet adhesion to immobilized FXI was abrogated in the presence of the low-density lipoprotein (LDL) receptor antagonist, receptor-associated protein (RAP), soluble recombinant apolipoprotein E receptor 2 (ApoER2), or the LDL-binding domain 1 or 2 of ApoER2. FXI supported wild-type murine platelet binding; in contrast, ApoER2-deficient murine platelets did not adhere to FXI. In the presence of shear, platelet aggregates formed on FXI or activated FXI (FXIa) surfaces, whereas the presence of RAP, binding domain 1 of ApoER2, or an anti-GPIb alpha mAb blocked platelet adhesion to FXI or FXIa under shear. Soluble FXI bound to immobilized ApoER2' with an affinity of 61 nmol/L. CONCLUSIONS This study has identified apolipoprotein E receptor 2 (ApoER2, LRP8), a member of the LDL receptor family, as a platelet receptor for FXI. The interaction of FXI with other cell types that express ApoER2 remains to be explored.
Collapse
Affiliation(s)
- Tara C White-Adams
- Division of Biomedical Engineering, Oregon Health & Science University School of Medicine, 3303 SW Bond Ave, Portland, OR 97239, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Abstract
Fibronectin, an ubiquitous extracellular matrix (ECM) glycoprotein, plays a major role in fundamental biological processes such as cell adhesion and migration, maintenance of normal cell morphology, cytoskeletal organization, and cell differentiation. Fibronectin is constructed from three types of independently folding protein module (Fn1, Fn2, and Fn3) and is found as a Fibrillar network in the ECM where it interacts with other ECM components and provides anchorage sites for cell surface integrin receptors. The mosaic nature of fibronectin permits it to be analyzed by a "dissection" strategy, where protein fragments generated by recombinant expression in E. coli, P. pastoris, and human cell lines are employed in structural and functional investigations. We describe methods suitable for the production of various fibronectin fragments for study by a variety of techniques including crystallography and electron microscopy but special mention is made of methods suitable for the production of samples for NMR studies.
Collapse
|
42
|
Hughes CE, Auger JM, McGlade J, Eble JA, Pearce AC, Watson SP. Differential roles for the adapters Gads and LAT in platelet activation by GPVI and CLEC-2. J Thromb Haemost 2008; 6:2152-9. [PMID: 18826392 PMCID: PMC2710801 DOI: 10.1111/j.1538-7836.2008.03166.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Accepted: 08/25/2008] [Indexed: 11/27/2022]
Abstract
BACKGROUND The adapter proteins SLP-76 and LAT have been shown to play critical roles in the activation of PLCgamma2 in platelets downstream of GPVI/FcRgamma and the C-type lectin receptor CLEC-2. SLP-76 is constitutively associated with the adapter Gads in platelets, which also binds to tyrosine phosphorylated LAT, thereby providing a potential pathway of regulation of SLP-76. OBJECTIVE In the present study, we have compared the role of Gads alongside that of LAT following activation of the major platelet glycoprotein receptors using mice deficient in the two adapter proteins. RESULTS Gads was found to be required for the efficient onset of aggregation and secretion in response to submaximal stimulation of GPVI and CLEC-2, but to be dispensable for activation following stronger stimulation of the two receptors. Gads was also dispensable for spreading induced through integrin alpha(IIb)beta(3) or the GPIb-IX-V complex. Further, Gads plays a negligible role in aggregate formation on collagen at an arteriolar rate of shear. In stark contrast, platelets deficient in the adapter LAT exhibit a marked decrease in aggregation and secretion following activation of GPVI and CLEC-2, and are unable to form stable aggregates on collagen at arteriolar shear. CONCLUSIONS The results demonstrate that Gads plays a key role in linking the adapter LAT to SLP-76 in response to weak activation of GPVI and CLEC-2 whereas LAT is required for full activation over a wider range of agonist concentrations. These results reveal the presence of a Gads-independent pathway of platelet activation downstream of LAT.
Collapse
Affiliation(s)
- C E Hughes
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, Medical School, University of Birmingham, Birmingham, UK.
| | | | | | | | | | | |
Collapse
|
43
|
Calaminus SDJ, Thomas S, McCarty OJT, Machesky LM, Watson SP. Identification of a novel, actin-rich structure, the actin nodule, in the early stages of platelet spreading. J Thromb Haemost 2008; 6:1944-52. [PMID: 18761725 DOI: 10.1111/j.1538-7836.2008.03141.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND During platelet spreading, the actin cytoskeleton undergoes marked changes, forming filopodia, lamellipodia and stress fibres. In the present study, we report the identification of a novel actin-rich structure, termed an actin nodule, which appears prior to lamellipodia and stress fibre formation. METHODS Platelet spreading was monitored using human platelets and mouse GFP-actin platelets using real-time and end-point DIC, and fluorescent and electron microscopy (EM). RESULTS We identified a small, novel actin structure, the actin nodule, in the early stages of adhesion and spreading, which we hypothesize to be a precursor of lamellipodia and stress fibres. Nodule formation shows an inverse correlation to Rho kinase and myosin-II activity, is independent of PI3-kinase, but dependent on Src kinase activity. Actin nodules contain multiple proteins, including Arp2/3, Fyn, Rac, and beta1- and beta3- integrins, but not Src. EM analysis revealed that actin filaments extend in all directions from the nodules. Actin nodules are present on multiple matrices, including fibrinogen, laminin and VWF + botrocetin. CONCLUSION This work identifies a novel platelet actin structure, which we propose is a precursor to both lamellipodia and stress fibres and acts to drive platelet spreading.
Collapse
Affiliation(s)
- S D J Calaminus
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, The Medical School, University of Birmingham, Birmingham, UK.
| | | | | | | | | |
Collapse
|
44
|
Tabuchi A, Kuebler WM. Endothelium–platelet interactions in inflammatory lung disease. Vascul Pharmacol 2008; 49:141-50. [DOI: 10.1016/j.vph.2008.06.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 04/21/2008] [Accepted: 06/13/2008] [Indexed: 01/15/2023]
|
45
|
White TC, Berny MA, Tucker EI, Urbanus RT, de Groot PG, Fernández JA, Griffin JH, Gruber A, McCarty OJT. Protein C supports platelet binding and activation under flow: role of glycoprotein Ib and apolipoprotein E receptor 2. J Thromb Haemost 2008; 6:995-1002. [PMID: 18489431 DOI: 10.1111/j.1538-7836.2008.02979.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Activated protein C (APC) regulates thrombin generation and inhibits apoptosis. Endothelial protein C receptor (EPCR)-bound protein C is activated by thrombomodulin-bound thrombin. APC inactivates coagulation factors (F)Va/VIIIa and generates cytoprotective signaling downstream of protease-activated receptor-1 (PAR-1). Binding of APC to EPCR both modifies and induces PAR-1 signaling, but it is unknown if protein C interacts with cells in an alternative manner. AIM To determine whether platelets possess receptors for protein C that can generate intracellular signals. RESULTS Immobilized protein C or APC supported platelet adhesion, lamellipodia formation and elevation of intracellular Ca(2+). Adhesion of platelets to protein C or APC was inhibited by soluble recombinant apolipoprotein E receptor 2' (ApoER2') and by receptor-associated protein (RAP), an inhibitor of the low-density lipoprotein receptor family. Under shear, surface-bound protein C supported platelet adhesion and aggregation in a glycoprotein (GP)Ibalpha-dependent manner, and adhesion of platelets to immobilized protein C was abrogated by the addition of soluble forms of ApoER2' or RAP. APC bound to purified recombinant ApoER2' or GPIbalpha. CONCLUSIONS Our data demonstrate that activation of platelets with rapid intracellular signaling caused by binding to immobilized protein C or APC occurs via mechanisms that require ApoER2 and GPIbalpha and that APC directly binds to purified ectodomains of the receptors ApoER2 and GPIbalpha. These findings imply that protein C and APC may directly promote cell signaling in other cells by binding to ApoER2 and/or GPIbalpha.
Collapse
Affiliation(s)
- T C White
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Berny MA, White TC, Tucker EI, Bush-Pelc LA, Di Cera E, Gruber A, McCarty OJ. Thrombin Mutant W215A/E217A Acts as a Platelet GPIb Antagonist. Arterioscler Thromb Vasc Biol 2008; 28:329-34. [DOI: 10.1161/atvbaha.107.156273] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Michelle A. Berny
- From the Departments of Biomedical Engineering (M.A.B., T.C.W., E.I.T., A.G., O.J.T.M.) and Cell and Developmental Biology (O.J.T.M.), Oregon Health and Science University, Portland; and Biochemistry and Molecular Biophysics (L.A.B.-P., E.D.C.), Washington University, St. Louis, Mo
| | - Tara C. White
- From the Departments of Biomedical Engineering (M.A.B., T.C.W., E.I.T., A.G., O.J.T.M.) and Cell and Developmental Biology (O.J.T.M.), Oregon Health and Science University, Portland; and Biochemistry and Molecular Biophysics (L.A.B.-P., E.D.C.), Washington University, St. Louis, Mo
| | - Erik I. Tucker
- From the Departments of Biomedical Engineering (M.A.B., T.C.W., E.I.T., A.G., O.J.T.M.) and Cell and Developmental Biology (O.J.T.M.), Oregon Health and Science University, Portland; and Biochemistry and Molecular Biophysics (L.A.B.-P., E.D.C.), Washington University, St. Louis, Mo
| | - Leslie A. Bush-Pelc
- From the Departments of Biomedical Engineering (M.A.B., T.C.W., E.I.T., A.G., O.J.T.M.) and Cell and Developmental Biology (O.J.T.M.), Oregon Health and Science University, Portland; and Biochemistry and Molecular Biophysics (L.A.B.-P., E.D.C.), Washington University, St. Louis, Mo
| | - Enrico Di Cera
- From the Departments of Biomedical Engineering (M.A.B., T.C.W., E.I.T., A.G., O.J.T.M.) and Cell and Developmental Biology (O.J.T.M.), Oregon Health and Science University, Portland; and Biochemistry and Molecular Biophysics (L.A.B.-P., E.D.C.), Washington University, St. Louis, Mo
| | - András Gruber
- From the Departments of Biomedical Engineering (M.A.B., T.C.W., E.I.T., A.G., O.J.T.M.) and Cell and Developmental Biology (O.J.T.M.), Oregon Health and Science University, Portland; and Biochemistry and Molecular Biophysics (L.A.B.-P., E.D.C.), Washington University, St. Louis, Mo
| | - Owen J.T. McCarty
- From the Departments of Biomedical Engineering (M.A.B., T.C.W., E.I.T., A.G., O.J.T.M.) and Cell and Developmental Biology (O.J.T.M.), Oregon Health and Science University, Portland; and Biochemistry and Molecular Biophysics (L.A.B.-P., E.D.C.), Washington University, St. Louis, Mo
| |
Collapse
|
47
|
Salati S, Zini R, Bianchi E, Testa A, Mavilio F, Manfredini R, Ferrari S. Role of CD34 antigen in myeloid differentiation of human hematopoietic progenitor cells. Stem Cells 2008; 26:950-9. [PMID: 18192237 DOI: 10.1634/stemcells.2007-0597] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
CD34 is a transmembrane protein that is strongly expressed on hematopoietic stem/progenitor cells (HSCs); despite its importance as a marker of HSCs, its function is still poorly understood, although a role in cell adhesion has been demonstrated. To characterize the function of CD34 antigen on human HSCs, we examined, by both inhibition and overexpression, the role of CD34 in the regulation of HSC lineage differentiation. Our results demonstrate that CD34 silencing enhances HSC granulocyte and megakaryocyte differentiation and reduces erythroid maturation. In agreement with these results, the gene expression profile of these cells reveals the upregulation of genes involved in granulocyte and megakaryocyte differentiation and the downregulation of erythroid genes. Consistently, retroviral-mediated CD34 overexpression leads to a remarkable increase in erythroid progenitors and a dramatic decrease in granulocyte progenitors, as evaluated by clonogenic assay. Together, these data indicate that the CD34 molecule promotes the differentiation of CD34+ hematopoietic progenitors toward the erythroid lineage, which is achieved, at least in part, at the expense of granulocyte and megakaryocyte lineages.
Collapse
Affiliation(s)
- Simona Salati
- Department of Biomedical Sciences, Biological Chemistry Section, University of Modena and Reggio Emilia, Via Campi 287, 41100 Modena, Italy
| | | | | | | | | | | | | |
Collapse
|
48
|
Lucena S, Salazar AM, Gil A, Arocha-Piñango CL, Guerrero B. The action of Lonomin V (Lonomia achelous) on fibronectin functional properties. Thromb Res 2007; 121:653-61. [PMID: 17997475 DOI: 10.1016/j.thromres.2007.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2007] [Revised: 07/03/2007] [Accepted: 07/24/2007] [Indexed: 10/22/2022]
Abstract
Lonomia achelous caterpillar, Lepidoptera distributed along some South American countries, induces a hemorrhagic syndrome in people who come into contact with its bristles. A clinical characteristic in these patients is that fresh healed wounds are re-opened and bleed. In order to explain this symptomatology, we evaluated the effect of Lonomin V (a protein isolated from L. achelous hemolymph), on some functional properties of fibronectin, which in turn plays an important role in the hemostasis. The effect of Lonomin V on fibronectin was studied by SDS-PAGE in reduced condition, binding to gelatin and heparin, crosslinking to fibrin and platelet adhesion. Formation of degradation products of 120, 66, 50, 40 and 29 kDa, some of which retain affinity to heparin and gelatin were observed; however, the fibronectin degradation fragments presented a significant decrease of crosslinking capacity to fibrin and platelet adhesion, suggesting that the proteolysis of fibronectin by Lonomin V induces changes in its crosslinking sites and on platelet receptors. These findings might partially explain the wound dehiscence observed in the patients. Due to its effect on adhesive proteins with concomitant impairment of some functional properties, Lonomin V might be useful for cellular adhesion studies involved in hemostasis such as platelet adhesion.
Collapse
Affiliation(s)
- Sara Lucena
- Instituto Venezolano de Investigaciones Científicas, Centro de Medicina Experimental, P.O. Box 21827, Caracas 1020-A, Venezuela
| | | | | | | | | |
Collapse
|
49
|
Abstract
BACKGROUND The platelet cytoskeleton mediates the dramatic change in platelet morphology that takes place upon activation and stabilizes thrombus formation. The Arp2/3 complex plays a vital role in these processes, providing the protrusive force for lamellipodia formation. The Arp2/3 complex is highly regulated by a number of actin-binding proteins including the haematopoietic-specific protein HS1 and its homologue cortactin. The present study investigates the role of HS1 in platelets using HS1-/- mice. RESULTS The present results demonstrate that HS1 is not required for platelet activation, shape change or aggregation. Platelets from HS1-/- mice spread normally on a variety of adhesion proteins and have normal F-actin and Arp2/3 complex distributions. Clot retraction, an actin-dependent process, is also normal in these mice. Platelet aggregation and secretion is indistinguishable between knock out and littermates and there is no increase in bleeding using the tail bleeding assay. CONCLUSION This study concludes that HS1 does not play a major role in platelet function. It is possible that a role for HS1 is masked by the presence of cortactin.
Collapse
Affiliation(s)
- Steven G Thomas
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, The Medical School, University of Birmingham, Edgbaston, Birmingham, UK
| | - Simon DJ Calaminus
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, The Medical School, University of Birmingham, Edgbaston, Birmingham, UK
| | - Jocelyn M Auger
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, The Medical School, University of Birmingham, Edgbaston, Birmingham, UK
| | - Stephen P Watson
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, The Medical School, University of Birmingham, Edgbaston, Birmingham, UK
| | - Laura M Machesky
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| |
Collapse
|
50
|
Tomlinson MG, Calaminus SD, Berlanga O, Auger JM, Bori-Sanz T, Meyaard L, Watson SP. Collagen promotes sustained glycoprotein VI signaling in platelets and cell lines. J Thromb Haemost 2007; 5:2274-83. [PMID: 17764536 DOI: 10.1111/j.1538-7836.2007.02746.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Glycoprotein (GP)VI is the major signaling receptor for collagen on platelets and signals via the associated FcRgamma-chain, which has an immunoreceptor tyrosine-containing activation motif (ITAM). OBJECTIVE To determine why GPVI-FcRgamma signals poorly, or not at all, in response to collagen in hematopoietic cell lines, despite robust responses to the GPVI-reactive snake venom toxin convulxin. METHODS AND RESULTS Using a nuclear factor of activated T-cells (NFAT) transcriptional reporter assay, a sensitive readout for sustained ITAM signaling, we demonstrate collagen-induced GPVI-FcRgamma signaling in hematopoietic cell lines. This is accompanied by relatively weak but sustained protein tyrosine phosphorylation, in contrast to the stronger but transient response to convulxin. Sustained signaling by collagen is also observed in platelets and is necessary for the maintenance of spreading on collagen. Finally, in cell lines, the inhibitory collagen receptor leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1), which is not expressed on platelets but is present on most hematopoietic cells, inhibits GPVI responses to collagen but not convulxin. CONCLUSION The inability of previous studies to readily detect GPVI collagen signaling in cell lines is probably because of the weak but sustained nature of the signal and the presence of the inhibitory collagen receptor LAIR-1. In platelets, we propose that GPVI-FcRgamma has evolved to transmit sustained signals in order to maintain spreading over several hours, as well as facilitating rapid activation through release of feedback agonists and integrin activation. The establishment of a cell line NFAT assay will facilitate the molecular dissection of GPVI signaling and the identification of GPVI antagonists in drug discovery.
Collapse
Affiliation(s)
- M G Tomlinson
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, The Medical School, University of Birmingham, Birmingham, UK.
| | | | | | | | | | | | | |
Collapse
|