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Aliotta A, Bertaggia Calderara D, Zermatten MG, Marchetti M, Alberio L. Thrombocytopathies: Not Just Aggregation Defects-The Clinical Relevance of Procoagulant Platelets. J Clin Med 2021; 10:jcm10050894. [PMID: 33668091 PMCID: PMC7956450 DOI: 10.3390/jcm10050894] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/31/2021] [Accepted: 02/12/2021] [Indexed: 01/08/2023] Open
Abstract
Platelets are active key players in haemostasis. Qualitative platelet dysfunctions result in thrombocytopathies variously characterized by defects of their adhesive and procoagulant activation endpoints. In this review, we summarize the traditional platelet defects in adhesion, secretion, and aggregation. In addition, we review the current knowledge about procoagulant platelets, focusing on their role in bleeding or thrombotic pathologies and their pharmaceutical modulation. Procoagulant activity is an important feature of platelet activation, which should be specifically evaluated during the investigation of a suspected thrombocytopathy.
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Affiliation(s)
- Alessandro Aliotta
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), CH-1010 Lausanne, Switzerland; (A.A.); (D.B.C.); (M.G.Z.); (M.M.)
| | - Debora Bertaggia Calderara
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), CH-1010 Lausanne, Switzerland; (A.A.); (D.B.C.); (M.G.Z.); (M.M.)
| | - Maxime G. Zermatten
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), CH-1010 Lausanne, Switzerland; (A.A.); (D.B.C.); (M.G.Z.); (M.M.)
| | - Matteo Marchetti
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), CH-1010 Lausanne, Switzerland; (A.A.); (D.B.C.); (M.G.Z.); (M.M.)
- Service de Médecine Interne, Hôpital de Nyon, CH-1260 Nyon, Switzerland
| | - Lorenzo Alberio
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), CH-1010 Lausanne, Switzerland; (A.A.); (D.B.C.); (M.G.Z.); (M.M.)
- Correspondence:
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Qi QM, Dunne E, Oglesby I, Schoen I, Ricco AJ, Kenny D, Shaqfeh ESG. In Vitro Measurement and Modeling of Platelet Adhesion on VWF-Coated Surfaces in Channel Flow. Biophys J 2019; 116:1136-1151. [PMID: 30824114 DOI: 10.1016/j.bpj.2019.01.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/13/2018] [Accepted: 01/15/2019] [Indexed: 12/11/2022] Open
Abstract
The process of platelet adhesion is initiated by glycoprotein (GP)Ib and GPIIbIIIa receptors on the platelet surface binding with von Willebrand factor on the vascular walls. This initial adhesion and detachment of a single platelet is a complex process that involves multiple bonds forming and breaking and is strongly influenced by the surrounding blood-flow environment. In addition to bond-level kinetics, external factors such as shear rate, hematocrit, and GPIb and GPIIbIIIa receptor densities have also been identified as influencing the platelet-level rate constants in separate studies, but this still leaves a gap in understanding between these two length scales. In this study, we investigate the fundamental relationship of the dynamics of platelet adhesion, including these interrelating factors, using a coherent strategy. We build a, to our knowledge, novel and computationally efficient multiscale model accounting for multibond kinetics and hydrodynamic effects due to the flow of a cellular suspension. The model predictions of platelet-level kinetics are verified by our microfluidic experiments, which systematically investigate the role of each external factor on platelet adhesion in an in vitro setting. We derive quantitative formulas describing how the rates of platelet adhesion, translocation, and detachment are defined by the molecular-level kinetic constants, the local platelet concentration near the reactive surface determined by red-blood-cell migration, the platelet effective reactive area due to its tumbling motion, and the platelet surface receptor density. Furthermore, if any of these aspects involved have abnormalities, e.g., in a disease condition, our findings also have clinical relevance in predicting the resulting change in the adhesion dynamics, which is essential to hemostasis and thrombosis.
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Affiliation(s)
- Qin M Qi
- Chemical Engineering, Stanford University, Stanford, California.
| | - Eimear Dunne
- Irish Centre for Vascular Biology and Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Irene Oglesby
- Irish Centre for Vascular Biology and Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Ingmar Schoen
- Irish Centre for Vascular Biology and Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Antonio J Ricco
- Electrical Engineering, Stanford University, Stanford, California
| | - Dermot Kenny
- Irish Centre for Vascular Biology and Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Eric S G Shaqfeh
- Chemical Engineering, Stanford University, Stanford, California; Mechanical Engineering, Stanford University, Stanford, California; Institute for Computational and Mathmatical Engineering, Stanford University, Stanford, California
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3
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Coller BS. Foreword: A Brief History of Ideas About Platelets in Health and Disease. Platelets 2019. [DOI: 10.1016/b978-0-12-813456-6.09988-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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5
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Favier R, Raslova H. Progress in understanding the diagnosis and molecular genetics of macrothrombocytopenias. Br J Haematol 2015; 170:626-39. [DOI: 10.1111/bjh.13478] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Remi Favier
- Institut National de la Santé et de la Recherche Médicale; U1170; Equipe Labellisée Ligue Contre le Cancer; Villejuif France
- Assistance Publique-Hôpitaux de Paris; Armand Trousseau Children Hospital; French Reference Center for Platelet Disorders; Haematological Laboratory; Paris France
| | - Hana Raslova
- Institut National de la Santé et de la Recherche Médicale; U1170; Equipe Labellisée Ligue Contre le Cancer; Villejuif France
- Faculté de Médecine; University Paris Saclay and University Paris-Sud 11; Le Kremlin-Bicêtre France
- Gustave Roussy; Villejuif France
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6
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Abstract
The study of blood ex vivo can occur in closed or open systems, with or without flow. Microfluidic devices, which constrain fluids to a small (typically submillimeter) scale, facilitate analysis of platelet function, coagulation biology, cellular biorheology, adhesion dynamics, and pharmacology and, as a result, can be an invaluable tool for clinical diagnostics. An experimental session can accommodate hundreds to thousands of unique clotting, or thrombotic, events. Using microfluidics, thrombotic events can be studied on defined surfaces of biopolymers, matrix proteins, and tissue factor, under constant flow rate or constant pressure drop conditions. Distinct shear rates can be generated on a device using a single perfusion pump. Microfluidics facilitated both the determination of intraluminal thrombus permeability and the discovery that platelet contractility can be activated by a sudden decrease in flow. Microfluidic devices are ideal for multicolor imaging of platelets, fibrin, and phosphatidylserine and provide a human blood analog to mouse injury models. Overall, microfluidic advances offer many opportunities for research, drug testing under relevant hemodynamic conditions, and clinical diagnostics.
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Affiliation(s)
- Thomas V Colace
- Department of Chemical and Biomolecular Engineering, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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7
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Feghhi S, Sniadecki NJ. Mechanobiology of platelets: techniques to study the role of fluid flow and platelet retraction forces at the micro- and nano-scale. Int J Mol Sci 2011; 12:9009-30. [PMID: 22272117 PMCID: PMC3257114 DOI: 10.3390/ijms12129009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 11/24/2011] [Accepted: 11/28/2011] [Indexed: 12/29/2022] Open
Abstract
Coagulation involves a complex set of events that are important in maintaining hemostasis. Biochemical interactions are classically known to regulate the hemostatic process, but recent evidence has revealed that mechanical interactions between platelets and their surroundings can also play a substantial role. Investigations into platelet mechanobiology have been challenging however, due to the small dimensions of platelets and their glycoprotein receptors. Platelet researchers have recently turned to microfabricated devices to control these physical, nanometer-scale interactions with a higher degree of precision. These approaches have enabled exciting, new insights into the molecular and biomechanical factors that affect platelets in clot formation. In this review, we highlight the new tools used to understand platelet mechanobiology and the roles of adhesion, shear flow, and retraction forces in clot formation.
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Affiliation(s)
- Shirin Feghhi
- Department of Mechanical Engineering, University of Washington, Stevens Way, Box 352600, Seattle, WA 98195, USA; E-Mail:
| | - Nathan J. Sniadecki
- Department of Mechanical Engineering, University of Washington, Stevens Way, Box 352600, Seattle, WA 98195, USA; E-Mail:
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98105, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-206-685-6591; Fax: +1-206-685-8047
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9
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Bernardi F, Marchetti G, Casonato A, Gemmati D, Patracchini P, Legnani C, DeRosa V, Girolami A, Conconi F. Characterization of polymorphic markers in the von Willebrand factor gene and pseudogene. Br J Haematol 2008. [DOI: 10.1111/j.1365-2141.1990.00234.x-i1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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10
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MEYER D, BAUMGARTNER HR. ROLE OF VON WILLEBRAND FACTOR IN PLATELET ADHESION TO THE SUBENDOTHELIUM. Br J Haematol 2008. [DOI: 10.1111/j.1365-2141.1983.00001.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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12
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Coller BS. Foreword: A Brief History of Ideas about Platelets in Health and Disease. Platelets 2007. [DOI: 10.1016/b978-012369367-9/50762-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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13
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Bergmeier W, Piffath CL, Goerge T, Cifuni SM, Ruggeri ZM, Ware J, Wagner DD. The role of platelet adhesion receptor GPIbalpha far exceeds that of its main ligand, von Willebrand factor, in arterial thrombosis. Proc Natl Acad Sci U S A 2006; 103:16900-5. [PMID: 17075060 PMCID: PMC1636551 DOI: 10.1073/pnas.0608207103] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
GPIbalpha binding to von Willebrand factor (VWF) exposed at a site of vascular injury is thought to be the first step in the formation of a hemostatic plug. However, our previous studies in VWF-deficient mice demonstrated delayed but not absent arterial thrombus formation, suggesting that, under these conditions, GPIbalpha may bind other ligands or that a receptor other than GPIbalpha can mediate platelet adhesion. Here, we studied thrombus formation in transgenic mice expressing GPIbalpha in which the extracellular domain was replaced by that of the human IL-4 receptor (IL4Ralpha/GPIbalpha-tg mice). Platelet adhesion to ferric chloride-treated mesenteric arterioles in IL4Ralpha/GPIbalpha-tg mice was virtually absent in contrast to avid adhesion in WT mice. As a consequence, arterial thrombus formation was inhibited completely in the mutant mice. Our studies further show that, when infused into WT recipient mice, IL4Ralpha/GPIbalpha-tg platelets or WT platelets lacking the 45-kDa N-terminal domain of GPIbalpha failed to incorporate into growing arterial thrombi, even if the platelets were activated before infusion. Surprisingly, platelets lacking beta3 integrins, which are unable to form thrombi on their own, incorporated efficiently into WT thrombi. Our studies provide in vivo evidence that GPIbalpha absolutely is required for recruitment of platelets to both exposed subendothelium and thrombi under arterial flow conditions. Thus, GPIbalpha contributes to arterial thrombosis by important adhesion mechanisms independent of the binding to VWF.
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Affiliation(s)
- Wolfgang Bergmeier
- CBR Institute for Biomedical Research and Department of Pathology, Harvard Medical School, Boston, MA 02115, USA.
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Affiliation(s)
- N O Solum
- Research Institute for Internal Medicine, Rikshospitalet, University of Oslo, Oslo, Norway
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15
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SOLUM NO, CLEMETSON KJ. The discovery and characterization of platelet GPIb. J Thromb Haemost 2004. [DOI: 10.1111/j.1538-7836.2004.01072.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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16
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Rathore V, Stapleton MA, Hillery CA, Montgomery RR, Nichols TC, Merricks EP, Newman DK, Newman PJ. PECAM-1 negatively regulates GPIb/V/IX signaling in murine platelets. Blood 2003; 102:3658-64. [PMID: 12893757 DOI: 10.1182/blood-2003-06-1888] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Platelet adhesion at sites of vascular injury is mediated, in part, by interaction of the platelet plasma membrane glycoprotein (GP) Ib/V/IX complex with von Willebrand Factor (VWF) presented on collagen-exposed surfaces. Recent studies indicate that GPIb/V/IX may be functionally coupled with the Fc receptor gamma (FcR gamma)-chain, which, by virtue of its cytoplasmic immunoreceptor tyrosine-based activation motif, sends activation signals into the cell. Platelet endothelial cell adhesion molecule-1 (PECAM-1) is an inhibitory receptor that has previously been shown to negatively regulate platelet responses to collagen, which transduces activation signals via the GPVI/FcR gamma-chain complex. To determine whether PECAM-1 might similarly regulate signals emanating from GPIb/FcR gamma, we compared activation and aggregation responses to VWF of PECAM-1-positive and PECAM-1-deficient murine platelets. PECAM-1 and the FcR gamma-chain became rapidly tyrosine phosphorylated in platelets following botrocetin-induced VWF binding, but FcR gamma-chain tyrosine phosphorylation was delayed in PECAM-1-positive, versus PECAM-1-deficient, platelets. PECAM-1-deficient platelets were hyperaggregable to VWF, exhibited enhanced spreading and, under conditions of arterial flow, formed markedly larger thrombi on immobilized VWF than did wild-type platelets. Taken together, these data support the notion that engagement of the GPIb complex, in addition to sending activation signals, also initiates a negative feedback loop involving PECAM-1 that controls the rate and extent of platelet activation.
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Affiliation(s)
- Vipul Rathore
- Blood Research Institute, The Blood Center of Southeastern Wisconsin, PO Box 2178, 638 N 18th St, Milwaukee, WI 53201, USA.
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Baglia FA, Badellino KO, Li CQ, Lopez JA, Walsh PN. RETRACTED: Factor XI binding to the platelet glycoprotein Ib-IX-V complex promotes factor XI activation by thrombin. J Biol Chem 2002; 277:1662-8. [PMID: 11696542 DOI: 10.1074/jbc.m108319200] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Factor XI binds to high affinity sites on the surface of stimulated platelets where it is efficiently activated by thrombin. Here, we provide evidence that the factor XI binding site on platelets is in the glycoprotein (GP) Ibalpha subunit of the GP Ib-IX-V complex as follows. 1) Bernard-Soulier platelets, lacking the complex, are deficient in factor XI binding; 2) two GP Ibalpha ligands, SZ-2 (a monoclonal antibody) and bovine von Willebrand factor, inhibit factor XI binding to platelets; 3) by surface plasmon resonance, factor XI bound specifically to glycocalicin (the extracellular domain of GP Ibalpha) in Zn(2+)-dependent fashion (K(d)( app) approximately 52 nm). We then investigated whether glycocalicin could promote factor XI activation by thrombin, another GP Ibalpha ligand. In the presence of high molecular weight kininogen (45 nm), Zn(2+) and Ca(2+) ions, thrombin activated factor XI in the presence of glycocalicin at rates comparable with those seen in the presence of dextran sulfate (1 microg/ml). With higher high molecular weight kininogen concentrations (360 nm), the rate of thrombin-catalyzed factor XI activation in the presence of glycocalicin was comparable with that on activated platelets. Thus, factor XI binds to the GP Ib-IX-V complex, promoting its activation by thrombin.
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Affiliation(s)
- Frank A Baglia
- The Sol Sherry Thrombosis Research Center and Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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18
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Radomski A, Stewart MW, Jurasz P, Radomski MW. Pharmacological characteristics of solid-phase von Willebrand factor in human platelets. Br J Pharmacol 2001; 134:1013-20. [PMID: 11682449 PMCID: PMC1573038 DOI: 10.1038/sj.bjp.0704345] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2001] [Revised: 08/09/2001] [Accepted: 08/16/2001] [Indexed: 11/09/2022] Open
Abstract
1. The pharmacological characteristics of solid-phase von Willebrand factor (svWF), a novel platelet agonist, were studied. 2. Washed platelet suspensions were obtained from human blood and the effects of svWF on platelets were measured using aggregometry, phase-contrast microscopy, flow cytometry and zymography. 3. Incubation of platelets with svWF (0.2 - 1.2 microg ml(-1)) resulted in their adhesion to the ligand, while co-incubations of svWF with subthreshold concentrations of ADP, collagen and thrombin resulted in aggregation. 4. 6B4 inhibitory anti-glycoprotein (GP)Ib antibodies abolished platelet adhesion stimulated by svWF, while aggregation was reduced in the presence of 6B4 and N-Acetyl-Pen-Arg-Gly-Asp-Cys, an antagonist of GPIIb/IIIa. 5. Platelet adhesion stimulated with svWF was associated with a concentration-dependent increase in expression of GPIb, but not of GPIIb/IIIa. 6. In contrast, collagen (0.5 - 10.0 microg ml(-1)) caused down-regulation of GPIb and up-regulation of GPIIb/IIIa in platelets. 7. Solid-phase vWF (1.2 microg ml(-1)) resulted in the release of MMP-2 from platelets. 8. Inhibition of MMP-2 with phenanthroline (10 microM), but not with aspirin or apyrase, inhibited platelet adhesion stimulated with svWF. 9. In contrast, human recombinant MMP-2 potentiated both the effects of svWF on adhesion and up-regulation of GPIb. 10. Platelet adhesion and aggregation stimulated with svWF were reduced by S-nitroso-n-acetyl-penicillamine, an NO donor, and prostacyclin. 11. Thus, stimulation of human platelets with svWF leads to adhesion and aggregation that are mediated via activation of GPIb and GPIIb/IIIa, respectively. 12. Mechanisms of activation of GPIb by svWF involve the release of MMP-2, and are regulated by NO and prostacyclin.
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Affiliation(s)
- Anna Radomski
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, T6G 2H7 Canada
| | | | - Paul Jurasz
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, T6G 2H7 Canada
| | - Marek W Radomski
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, T6G 2H7 Canada
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19
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Jurasz P, Stewart MW, Radomski A, Khadour F, Duszyk M, Radomski MW. Role of von Willebrand factor in tumour cell-induced platelet aggregation: differential regulation by NO and prostacyclin. Br J Pharmacol 2001; 134:1104-12. [PMID: 11682459 PMCID: PMC1573036 DOI: 10.1038/sj.bjp.0704343] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2001] [Revised: 08/08/2001] [Accepted: 08/15/2001] [Indexed: 02/02/2023] Open
Abstract
1. We have studied the effects of a novel agonist, solid-phase von Willebrand Factor (sVWF), on tumour cell-induced platelet aggregation (TCIPA). 2. Washed platelet suspensions were obtained from human blood and the effects of HT-1080 human fibrosarcoma cells and sVWF on platelets were studied using aggregometry, phase-contrast microscopy, and flow cytometry. 3. Incubation of platelets with sVWF (1.2 microg ml(-1)) and HT-1080 cells (5 x 10(3) ml(-1)) resulted in a two-phased reaction characterized first by the adhesion of platelets to sVWF, then by aggregation. 4. TCIPA in the presence of sVWF was inhibited by S-nitroso-glutathione (GSNO, 100 microM) and prostacyclin (PGI(2), 30 nM). 5. Platelet activation in the presence of tumour cells and sVWF resulted in the decreased surface expression of platelet glycoprotein (GP)Ib and up-regulation of GPIIb/IIIa receptors. 6. Pre-incubation of platelets with PGI(2) (30 nM) resulted in inhibition of sVWF-tumour cell-stimulated platelet surface expression of GPIIb/IIIa as measured by flow cytometry using antibodies directed against both non-activated and activated receptor. In contrast, GSNO (100 microM) did not affect sVWF-tumour cell-stimulated platelet surface expression of GPIIb/IIIa. 7. Flow cytometry performed with PAC-1 antibodies that bind only to the activated GPIIb/IIIa revealed that GSNO (100 microM) caused inhibition of activation of GPIIb/IIIa. 8. The inhibitors exerted no significant effects on TCIPA-mediated changes in GPIb. 9. Thus, sVWF potentiates the platelet-aggregatory activity of HT-1080 cells and these effects appear to be mediated via up-regulation of platelet GPIIb/IIIa. 10. Prostacyclin and NO inhibit TCIPA-sVWF-mediated platelet aggregation. The mechanisms of inhibition of this aggregation by PGI(2) differ from those of NO.
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Affiliation(s)
- Paul Jurasz
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | | | - Anna Radomski
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Fadi Khadour
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Marek Duszyk
- Department of Physiology, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Marek W Radomski
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
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20
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Sakariassen KS, Hanson SR, Cadroy Y. Methods and models to evaluate shear-dependent and surface reactivity-dependent antithrombotic efficacy. Thromb Res 2001; 104:149-74. [PMID: 11672758 DOI: 10.1016/s0049-3848(01)00344-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The purpose of the present communication is to evaluate the importance of blood flow and surface reactivity for measurement of antithrombotic drug activity or efficacy in selected model systems of thrombus formation. Such information is essential for proper evaluation of antithrombotic drug profiles. The continuous development of flow-dependent thrombosis models for in vitro (anticoagulated blood) and ex vivo (native blood) studies and their application in in vivo animal models from the early 1970s and onwards are briefly considered. Central to this process was the development of various types of perfusion chambers in which a thrombogenic surface is exposed to flowing blood. Such perfusion chambers have been inserted into arteriovenous (AV) shunts in baboon, pig, dog, and rabbit. These approaches have allowed reproducible testing of traditional and novel experimental antithrombotic drugs, and studies on novel drug strategies under well-defined shear conditions and surface reactivity. Shear-dependent antithrombotic efficacy in these models is observed with anticoagulants such as unfractionated heparin, low-molecular weight heparins, or selective inhibitors of thrombin, Factor Xa, or Factor VIIa. However, the degree of shear dependency depends on the nature of the thrombogenic surface, e.g., the inhibition is more pronounced on a tissue factor (TF)-rich surface than on a collagen-rich surface, particularly at venous or low arterial shear. Platelet antagonists such as the COX-1 inhibitor aspirin, inhibitors of thromboxane A2 (TxA2) synthetase, the TxA2 platelet receptor, and of von Willebrand factor (vWf) are shear dependent also, being more efficient at high arterial shear. In contrast, the platelet ADP antagonist clopidogrel, or antagonists to the active platelet membrane glycoprotein IIb-IIIa complex (GPIIb-IIIa) are shear independent. At extremely high arterial shear, which activates platelets and elicit aggregates of circulating platelets, aspirin looses its antithrombotic effect, whereas ADP and GPIIb-IIIa antagonists still interrupt thrombus formation. In general, results obtained with these models mimic and predict antithrombotic efficacy in man when comparison is possible. Information on antithrombotic efficacy in flow devices with various thrombogenic surfaces is now sufficiently available to suggest recommendations for experimental conditions, particularly with regard to blood flow and reactive surfaces.
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Affiliation(s)
- K S Sakariassen
- Department of Lead Pharmacology, Pharmacia Corporation, Uppsala and Stockholm, Sweden.
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21
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Englund GD, Bodnar RJ, Li Z, Ruggeri ZM, Du X. Regulation of von Willebrand factor binding to the platelet glycoprotein Ib-IX by a membrane skeleton-dependent inside-out signal. J Biol Chem 2001; 276:16952-9. [PMID: 11278380 DOI: 10.1074/jbc.m008048200] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The platelet receptor for von Willebrand factor (vWF), glycoprotein Ib-IX (GPIb-IX), mediates initial platelet adhesion and activation. We show here that the receptor function of GPIb-IX is regulated intracellularly via its link to the filamin-associated membrane skeleton. Deletion of the filamin binding site in GPIb(alpha) markedly enhances ristocetin- (or botrocetin)-induced vWF binding and allows GPIb-IX-expressing cells to adhere to immobilized vWF under both static and flow conditions. Cytochalasin D (CD) that depolymerizes actin also enhances vWF binding to wild type GPIb-IX. Thus, vWF binding to GPIb-IX is negatively regulated by the filamin-associated membrane skeleton. In contrast to native vWF, binding of the isolated recombinant vWF A1 domain to wild type and filamin binding-deficient mutants of GPIb-IX is comparable, suggesting that the membrane skeleton-associated GPIb-IX is in a state that prevents access to the A1 domain in macromolecular vWF. In platelets, there is a balance of membrane skeleton-associated and free forms of GPIb-IX. Treatment of platelets with CD increases the free form and enhances vWF binding. CD also reverses the inhibitory effects of prostaglandin E1 on vWF binding to GPIb-IX. Thus, GPIb-IX-dependent platelet adhesion is doubly controlled by vWF conformation and a membrane skeleton-dependent inside-out signal.
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Affiliation(s)
- G D Englund
- Department of Pharmacology, University of Illinois, College of Medicine, Chicago, Illinois 60612, USA
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Abstract
1. Cell-cell and cell-matrix adhesive interactions are critical for a wide range of physiological processes, including embryogenesis, inflammation, immunity and haemostasis. 2. The ability of circulating blood cells, such as platelets and leucocytes, to adhere to sites of vascular injury is complicated by the presence of blood flow, which imposes hydrodynamic forces on adhesion contacts. 3. To overcome this problem, platelets and leucocytes have evolved specific adhesion receptors with unique biomechanical properties that enable these cells to adhere to the vessel wall under flow conditions. 4. Platelet adhesion in the normal circulation appears to be a multiple-step process involving an initial reversible interaction between the platelet adhesion receptor glycoprotein Ib-IX-V and the vascular adhesion protein von Willebrand factor. Once tethered to the vessel wall, platelets form irreversible adhesion contacts through the binding of one or more platelet integrins to specific subendothelial matrix proteins. 5. There is now a wealth of evidence demonstrating that these receptors not only mediate platelet adhesion, but also transduce signals leading to platelet activation. 6. In the present review, we will briefly discuss the current understanding of the specific roles of individual platelet receptors in supporting the haemostatic function of platelets and discuss mechanisms by which these receptors induce platelet activation.
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Affiliation(s)
- S M Dopheide
- Australian Centre for Blood Diseases, Department of Medicine, Monash Medical School, Victoria, Australia
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23
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Roth GJ, Yagi M, Bastian LS. The platelet glycoprotein Ib-V-IX system: regulation of gene expression. Stem Cells 2001; 14 Suppl 1:188-93. [PMID: 11012220 DOI: 10.1002/stem.5530140724] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Platelet glycoproteins (GPs) Ib-V-IX form the surface receptor for von Willebrand factor, and this receptor-ligand interaction mediates the shear-dependent adhesion of platelets to damaged arterial vessel walls. The receptor is a multicomponent structure consisting of four distinct polypeptides (heterodimeric GPIb: Ib alpha-Mr143k and Ib beta-Mr22k; GPV-Mr83k; GPIX-Mr20k), and each of the four cDNAs and genes has been cloned and characterized. The genes appear to have evolved from a common progenitor genomic sequence related to that encoding GPIX. They share simple structures with few introns and possess common consensus regulatory sequences (GATA, ets, Sp-1) in their 5' flanks. Both the GPIb alpha and the GPIX promoters have been analyzed by transfection of reporter constructs into hematopoietic and nonhematopoietic cells. The promoters function in a tissue-specific fashion, and gel shift and mutational analyses indicate that GATA and ets sequences regulate activity. In the case of the GPIX promoter, footprints confirm the role of the ets-related consensus region. Recent studies of GPIb beta transcriptional regulation suggest that an aberrant polyadenylation signal, located in the 3' end of the gene immediately upstream of the GPIb beta gene, allows in vitro expression of a rare extended fusion transcript encoding both the upstream protein and GPIb beta. Little detailed information is available in regard to expression of the GPV gene. In summary, the genes of the GPIb-V-IX system display features of other megakaryocyte/platelet genes, but the unique regulatory events that direct the selective expression of these genes in megakaryocytes remain to be defined.
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Affiliation(s)
- G J Roth
- Hematology Section, Medical and Research Services, Seattle Veterans Administration Medical Center and the University of Washington, 98108, USA
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24
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Antonucci JV, Martin ES, Hulick PJ, Joseph A, Martin SE. Bernard-Soulier syndrome: common ancestry in two African American families with the GP Ib alpha Leu129Pro mutation. Am J Hematol 2000; 65:141-8. [PMID: 10996832 DOI: 10.1002/1096-8652(200010)65:2<141::aid-ajh9>3.0.co;2-h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Bernard-Soulier syndrome (BSs) is a rare bleeding disorder characterized by circulating giant platelets, thrombocytopenia, and a prolonged bleeding time. BSs usually has an autosomal recessive inheritance pattern, with a preponderance of Caucasian and Japanese ancestry when the ethnic background has been reported. Underlying this disorder of platelet function is a defect in the platelet glycoprotein (GP) Ib-IX-V complex, composed of four polypeptides, GP Ib alpha, GP Ib beta, GP IX, and GP V. Molecular characterization of individuals with BSs has identified mutations in the GP Ib alpha, GP Ib beta, and GP IX genes responsible for the expressed phenotype. In this study, we report a family of African-American descent, with autosomal recessive BSs showing a point mutation in codon 129 of the GP Ib alpha gene. This mutation, CTC:wild-type to CCC:mutant, is similar to that of another African American family where the resulting leucine to proline substitution in the 5(th) leucine-rich repeat of GP Ib alpha is responsible for the observed BSs phenotype. Comparison of the intragenic polymorphisms of GP Ib alpha, as well as microsatellite markers in a 17.5 cM region of chromosome 17p12 that contains the GP Ib alpha gene, suggests that, although socially unrelated, the Leu129Pro mutation in these two families has a common founder.
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Affiliation(s)
- J V Antonucci
- Department of Medicine, Christiana Care Health System, Wilmington, Delaware, USA
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25
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Ware J, Russell S, Ruggeri ZM. Generation and rescue of a murine model of platelet dysfunction: the Bernard-Soulier syndrome. Proc Natl Acad Sci U S A 2000; 97:2803-8. [PMID: 10706630 PMCID: PMC16010 DOI: 10.1073/pnas.050582097] [Citation(s) in RCA: 190] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The human Bernard-Soulier syndrome is an autosomal recessive disorder of platelet dysfunction presenting with mild thrombocytopenia, circulating "giant" platelets and a bleeding phenotype. The bleeding in patients with the Bernard-Soulier syndrome is disproportionately more severe than suggested by the reduced platelet count and is explained by a defect in primary hemostasis owing to the absence of the platelet glycoprotein (GP) Ib-IX-V membrane receptor. However, the molecular basis for the giant platelet phenotype and thrombocytopenia have remained unresolved but assumed to be linked to an absent receptor complex. We have disrupted the gene encoding the alpha-subunit of mouse GP Ib-IX-V (GP Ibalpha) and describe a murine model recapitulating the hallmark characteristics of the human Bernard-Soulier syndrome. The results demonstrate a direct link between expression of a GP Ib-IX-V complex and normal megakaryocytopoiesis and platelet morphogenesis. Moreover, using transgenic technology the murine Bernard-Soulier phenotype was rescued by expression of a human GP Ibalpha subunit on the surface of circulating mouse platelets. Thus, an in vivo model is defined for analysis of the human GP Ib-IX-V receptor and its role in the processes performed exclusively by megakaryocytes and platelets.
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Affiliation(s)
- J Ware
- Roon Research Center for Arteriosclerosis and Thrombosis, Division of Experimental Hemostasis and Thrombosis, Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA.
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26
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Mhawech P, Saleem A. Inherited giant platelet disorders. Classification and literature review. Am J Clin Pathol 2000; 113:176-90. [PMID: 10664620 DOI: 10.1309/fc4h-lm5v-vcw8-dnju] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Inherited giant platelet disorders are extremely rare. The aim of this article is to review the clinical and laboratory features of this heterogeneous group and to arrive at a working classification. We conducted our literature search using the National Library of Medicine database. A total of 12 clinical entities were described. We classified them into 4 groups depending on the clinical and structural abnormalities. The pathophysiology of these disorders is largely unknown, and more research is needed, particularly in the light of recent advances in laboratory medicine. This review may provide a valuable reference for clinicians and may form a basis for future classification and research.
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Affiliation(s)
- P Mhawech
- Department of Pathology at Baylor College of Medicine, Houston, TX 77030, USA
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27
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Monteiro MR, Shapiro SS, Takafuta T, Menezes DW, Murphy GF. Von Willebrand factor receptor GPIb alpha is expressed by human factor XIIIa-positive dermal dendrocytes and is upregulated by mast cell degranulation. J Invest Dermatol 1999; 113:272-6. [PMID: 10469316 DOI: 10.1046/j.1523-1747.1999.00665.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
GPIb alpha, a glycoprotein component of the GPIb-IX-V complex, serves as a platelet membrane receptor that mediates adhesion to von Willebrand factor normally present in the vascular subendothelium. Recent data have demonstrated that GPIb alpha is not restricted to platelets, but is also expressed by endothelium in vitro. In this study, we describe the expression and distribution of GPIb alpha in normal adult and neonatal human skin. GPIb alpha is present, as detected by immunohistochemistry, on endothelial cells and on highly dendritic cells localized within the perivascular space, dermal-epidermal junction, and reticular dermis. By dual-labeling immunofluorescence and confocal microscopy, GPIb alpha-positive cells within the dermal interstitium are demonstrated to represent factor XIIIa-positive dermal dendrocytes. In organ cultures of neonatal human foreskin, mast cell degranulation induced by either substance P or compound 48/80 resulted in transiently increased GPIb alpha expression by dermal dendrocytes. Because the GPIb-IX-V complex plays a part in regulating hemostasis and may be important for cellular interactions with extracellular matrix molecules, these data provide additional insight into the potential function of FXIIIa-positive dermal dendrocytes in skin remodeling and repair.
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Affiliation(s)
- M R Monteiro
- Jefferson Medical College, Department of Pathology, Philadelphia, Pennsylvania 19107, USA
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Real-Time Analysis of Mural Thrombus Formation in Various Platelet Aggregation Disorders: Distinct Shear-Dependent Roles of Platelet Receptors and Adhesive Proteins Under Flow. Blood 1999. [DOI: 10.1182/blood.v94.3.968.415a13_968_975] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We evaluated real-time processes of platelet thrombus formation on a collagen surface in a flow chamber with whole blood from patients with various platelet aggregation disorders, such as Bernard-Soulier syndrome (BSS), Glanzmann’s thrombasthenia (GTA), type 3 von Willebrand disease (vWD), and congenital afibrinogenemia (Af), who lack platelet glycoprotein (GP) Ib-IX complex, GP IIb-IIIa, von Willebrand factor (vWF), and fibrinogen, respectively. Blood from GTA patients showed impaired thrombus growth but significant initial platelet-surface interaction under all shear conditions tested (50 to 1,500 s−1). By contrast, blood from patients with BSS or type 3 vWD showed no platelet-surface interaction under high shear (≥1,210 s−1) but normal thrombus formation under low shear (≤340 s−1). When shear rate was increased stepwise to 1,500 s−1 during perfusion, the thrombus growth observed in type 3 vWD or BSS under low shear was arrested, whereas that in control blood was sharply accelerated as a function of shear rate. Overall thrombus formation in Af appeared indistinguishable from that of a control under shear rates between 50 and 1,500 s−1. However, Af thrombi formed under such conditions collapsed immediately when shear rate was further increased to 4,500 s−1, whereas thrombi of type 3 vWD or BSS formed under low shear were stable even when shear rate was elevated to 9,000 s−1 during perfusion. These findings suggest that distinct molecular mechanisms underlie the pathologic bleeding in these diseases and point to the distinct roles of two major adhesive proteins, vWF and fibrinogen. In mural thrombus formation under flow conditions, vWF, perhaps mainly through its interaction with GP Ib-IX, acts as an “initiator and promoter,” whereas fibrinogen, via its binding to GP IIb-IIIa, acts as a “stabilizer” against heightened shear forces that could lead to peeling off of platelets from the surface.
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29
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Fibrin-Dependent Platelet Procoagulant Activity Requires GPIb Receptors and von Willebrand Factor. Blood 1999. [DOI: 10.1182/blood.v93.2.564] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractThrombin generation in platelet-rich plasma (PRP) involves complex interactions between platelets and coagulation proteins. We previously reported that the addition of fibrin to PRP enhances tissue-factor initiated thrombin generation by ≈ 40%, and the current studies were designed to assess the mechanism(s) underlying thrombin generation in the absence and presence of fibrin. Blocking platelet GPIIb/IIIa + vβ3 receptors with a monoclonal antibody (MoAb) inhibited basal thrombin generation, but did not affect the enhancement produced by fibrin. In contrast, blocking GPIb with any of three different MoAbs had no effect on basal thrombin generation, but essentially eliminated fibrin enhancement of thrombin generation. When thrombin generation was tested in PRP deficient in von Willebrand factor (vWF), both basal and fibrin-enhanced thrombin generation were markedly reduced, and the addition of factor VIII did not normalize thrombin generation. Botrocetin, which induces the binding of vWF to GPIb, enhanced thrombin generation. In all studies, the ability of PRP to support thrombin generation correlated with the production of platelet-derived microparticles and serum platelet-derived procoagulant activity. Thus, two separate mechanisms, both of which depend on vWF, appear to contribute to platelet-derived procoagulant activity: one is independent of fibrin and relies primarily on GPIIb/IIIa, but with a minor contribution from vβ3; and the other is fibrin-dependent and relies on GPIb. These data may have implications for understanding the mechanisms of the abnormalities in serum prothrombin times reported in Bernard-Soulier syndrome, hemorrhage in von Willebrand disease (vWD), and the increased risk of thrombosis associated with elevated vWF levels.
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30
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Abstract
Thrombin generation in platelet-rich plasma (PRP) involves complex interactions between platelets and coagulation proteins. We previously reported that the addition of fibrin to PRP enhances tissue-factor initiated thrombin generation by ≈ 40%, and the current studies were designed to assess the mechanism(s) underlying thrombin generation in the absence and presence of fibrin. Blocking platelet GPIIb/IIIa + vβ3 receptors with a monoclonal antibody (MoAb) inhibited basal thrombin generation, but did not affect the enhancement produced by fibrin. In contrast, blocking GPIb with any of three different MoAbs had no effect on basal thrombin generation, but essentially eliminated fibrin enhancement of thrombin generation. When thrombin generation was tested in PRP deficient in von Willebrand factor (vWF), both basal and fibrin-enhanced thrombin generation were markedly reduced, and the addition of factor VIII did not normalize thrombin generation. Botrocetin, which induces the binding of vWF to GPIb, enhanced thrombin generation. In all studies, the ability of PRP to support thrombin generation correlated with the production of platelet-derived microparticles and serum platelet-derived procoagulant activity. Thus, two separate mechanisms, both of which depend on vWF, appear to contribute to platelet-derived procoagulant activity: one is independent of fibrin and relies primarily on GPIIb/IIIa, but with a minor contribution from vβ3; and the other is fibrin-dependent and relies on GPIb. These data may have implications for understanding the mechanisms of the abnormalities in serum prothrombin times reported in Bernard-Soulier syndrome, hemorrhage in von Willebrand disease (vWD), and the increased risk of thrombosis associated with elevated vWF levels.
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31
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32
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33
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Bernard-Soulier Syndrome Caused by a Dinucleotide Deletion and Reading Frameshift in the Region Encoding the Glycoprotein Ibα Transmembrane Domain. Blood 1997. [DOI: 10.1182/blood.v90.7.2634.2634_2634_2643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the molecular genetic and biosynthetic basis of Bernard-Soulier syndrome in a severely affected white woman. Flow cytometric analysis showed a severe deficiency of glycoprotein (GP) Ib, GP IX, and GP V on the surface of her platelets. Similarly, GP Ibα was undetectable by immunoblot analysis of platelet lysates. Surprisingly, a large quantity of a 70-kD protein (which probably represents a GP Ibα degradation product) was found in the patient's plasma in much greater quantities than in the plasma of an unaffected individual. To analyze the molecular lesion responsible for the disorder, we amplified and sequenced gene segments corresponding to the entire coding regions of the GP Ibα, GP Ibβ, and GP IX genes. The patient was homozygous for a specific GP Ibα allele that contained two tandem VNTR repeats in the region encoding the macroglycopeptide (C variant) and three differences from the published GP Ibα gene sequence. Two mutations were unlikely to be involved in the disorder: the substitution of a single base (T → C) in the second nucleotide of exon 2, which is in the 5′ untranslated region of the GP Ibα transcript, and a silent mutation in the third base of the codon for Arg342 (A → G) that does not change the amino acid sequence. The third mutation was a deletion of the last two bases of the codon for Tyr492 (TAT). This mutation causes a frameshift that alters the GP Ibα amino acid sequence, beginning within its transmembrane region. The mutant polypeptide contains 81 novel amino acids and is 38 amino acids shorter than its wild-type counterpart. The new sequence changes the hydrophobic nature of the transmembrane domain and greatly decreases the net positive charge of what had been the cytoplasmic domain. The deletion mutation was introduced into the GP Ibα cDNA, alone and in combination with the 5′ mutation, and expressed in Chinese hamster ovary (CHO) cells. The deletion alone severely reduced GP Ibα expression on the cell surface. Expression was not decreased further by addition of the 5′ mutation, confirming that the deletion was the cause of the Bernard-Soulier phenotype. Stable cell lines expressing the mutant polypeptide secreted large amounts of the polypeptide into the medium, suggesting that the mutant anchors poorly in the plasma membrane. Nevertheless, a fraction of the mutant was able to associate with GP Ibβ, as demonstrated by their coimmunoprecipitation with a GP Ibβ antibody.
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34
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35
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Bernard-Soulier Syndrome Caused by a Dinucleotide Deletion and Reading Frameshift in the Region Encoding the Glycoprotein Ibα Transmembrane Domain. Blood 1997. [DOI: 10.1182/blood.v90.7.2634] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractWe investigated the molecular genetic and biosynthetic basis of Bernard-Soulier syndrome in a severely affected white woman. Flow cytometric analysis showed a severe deficiency of glycoprotein (GP) Ib, GP IX, and GP V on the surface of her platelets. Similarly, GP Ibα was undetectable by immunoblot analysis of platelet lysates. Surprisingly, a large quantity of a 70-kD protein (which probably represents a GP Ibα degradation product) was found in the patient's plasma in much greater quantities than in the plasma of an unaffected individual. To analyze the molecular lesion responsible for the disorder, we amplified and sequenced gene segments corresponding to the entire coding regions of the GP Ibα, GP Ibβ, and GP IX genes. The patient was homozygous for a specific GP Ibα allele that contained two tandem VNTR repeats in the region encoding the macroglycopeptide (C variant) and three differences from the published GP Ibα gene sequence. Two mutations were unlikely to be involved in the disorder: the substitution of a single base (T → C) in the second nucleotide of exon 2, which is in the 5′ untranslated region of the GP Ibα transcript, and a silent mutation in the third base of the codon for Arg342 (A → G) that does not change the amino acid sequence. The third mutation was a deletion of the last two bases of the codon for Tyr492 (TAT). This mutation causes a frameshift that alters the GP Ibα amino acid sequence, beginning within its transmembrane region. The mutant polypeptide contains 81 novel amino acids and is 38 amino acids shorter than its wild-type counterpart. The new sequence changes the hydrophobic nature of the transmembrane domain and greatly decreases the net positive charge of what had been the cytoplasmic domain. The deletion mutation was introduced into the GP Ibα cDNA, alone and in combination with the 5′ mutation, and expressed in Chinese hamster ovary (CHO) cells. The deletion alone severely reduced GP Ibα expression on the cell surface. Expression was not decreased further by addition of the 5′ mutation, confirming that the deletion was the cause of the Bernard-Soulier phenotype. Stable cell lines expressing the mutant polypeptide secreted large amounts of the polypeptide into the medium, suggesting that the mutant anchors poorly in the plasma membrane. Nevertheless, a fraction of the mutant was able to associate with GP Ibβ, as demonstrated by their coimmunoprecipitation with a GP Ibβ antibody.
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36
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Donnér M, Karpman D, Kristoffersson AC, Winqvist I, Holmberg L. Recurrent mutation Asn45-->Ser of glycoprotein IX in Bernard-Soulier syndrome. Eur J Haematol Suppl 1996; 57:178-9. [PMID: 8856096 DOI: 10.1111/j.1600-0609.1996.tb01357.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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37
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André P, Hamaud P, Bal dit Sollier C, Drouet V, Garfinkel LI, Uzan A, Caen JP, Drouet LO. Guinea pig blood: a model for the pharmacologic modulation of the GPIb/IX-vWF axis. Thromb Res 1996; 83:127-36. [PMID: 8837311 DOI: 10.1016/0049-3848(96)00113-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Antithrombotic activity of two recombinant GPIb-binding fragments of vWF, RG12986 (residues 445-733), and VCL (residues 504-728), were assessed in an ex vivo capillary perfusion chamber exposing human type III collagen to native nonanticoagulated guinea pig blood. Platelet adhesion and thrombus formation were evaluated by computer assisted morphometry for two shear rates (650 and 1800 s-1) and for two perfusion times (1.5 and 4 min). At 1800 s-1 and 4 min of perfusion, platelet adhesion decreased from 63 +/- 7% for control, to 46 +/- 4% for 20 mg/kg RG12986, and to 29 +/- 5% for 4 mg/kg VCL, and the mean thrombus height dropped from 40 +/- 8 microns to 24 +/- 3 microns and 7.5 +/- 1 microns, respectively. The two doses did not change bleeding time values. Our results suggest that guinea pig blood and the circular perfusion chamber represent a good model for the evaluation of limited amount of GPIb/IX-vWF axis inhibitors.
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Abstract
Qualitative platelet disorders are described and reviewed above. The acquired platelet function defects are very common, and sometimes result in hemorrhage, especially in association with trauma or surgery. However, the specific biochemical defect is absent, and no characterized platelet abnormalities have been recognized. On the other hand, the hereditary qualitative platelet defects are rare, but the platelet abnormalities are characteristic. The study of these patients had led to an increased understanding of the normal primary hemostatic mechanism. Recently, the molecular basis analysis of the platelet defects has been developed. This will help us understand the molecular events involved in platelet adhesion and aggregation.
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Affiliation(s)
- I Fuse
- First Department of Internal Medicine, Niigata University School of Medicine, Japan
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39
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Estry DW, Mattson JC, Oesterle JR, Mahoney GJ, Patterson WR, Bell TG. Basset Hound Hereditary Thrombopathy: An inherited disorder with defective platelet aggregation despite normal fibrinogen binding and receptor mobility. ACTA ACUST UNITED AC 1995. [DOI: 10.1007/bf02044139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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40
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Zahger D, Fishbein MC, Garfinkel LI, Shah PK, Forrester JS, Regnstrom J, Yano J, Cercek B. VCL, an antagonist of the platelet GP1b receptor, markedly inhibits platelet adhesion and intimal thickening after balloon injury in the rat. Circulation 1995; 92:1269-73. [PMID: 7648675 DOI: 10.1161/01.cir.92.5.1269] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Arterial injury is immediately followed by platelet adhesion at the site of injury, a process that requires the interaction of subendothelial von Willebrand factor with the platelet GP1b receptor. VCL, a recombinant von Willebrand factor GP1b binding domain, inhibits platelet binding to von Willebrand factor. The aim of this study was to determine whether VCL inhibits platelet adhesion at the site of arterial injury and affects neointimal thickening after injury in rats. METHODS AND RESULTS Sprague-Dawley rats were randomized to receive VCL, 4 mg/kg bolus followed by a continuous infusion of 2 mg.kg-1.h-1 for 72 hours, or an identical volume of saline. Balloon injury of the femoral artery was performed 15 minutes after the initial bolus injection of VCL. Scanning electron microscopy performed 1 and 3 days after injury indicated that VCL-treated rats had > 80% reduction in the number of platelets adherent to the vessel wall at the site of injury compared with controls (P < .003). Histological examination at day 14 showed that, compared with controls, VCL-treated rats had a 60% reduction in the intima-media ratio (0.21 +/- 0.03 versus 0.53 +/- 0.06, P = .001) and a reduced luminal area stenosis (12 +/- 3% versus 38 +/- 10%, P = .04). At 28 days after injury, there was no rebound of neointimal thickening in VCL-treated rats (intima-media ratio, 0.19 +/- 0.04; luminal stenosis, 17 +/- 5%). The difference between VCL-treated rats and control rats persisted but was attenuated (intima-media ratio, 0.19 +/- 0.04 versus 0.28 +/- 0.1, P = .162; luminal stenosis, 17 +/- 5% versus 31 +/- 5%, P = .058) as neointimal thickening regressed in untreated rats. With the use of proliferating cell nuclear antigen immunohistochemistry on day 3, VCL had no effect on smooth muscle cell (SMC) proliferation. CONCLUSIONS Antagonism of the platelet GP1b receptor by VCL profoundly decreased platelet deposition at the site of balloon injury in the rat femoral artery. This effect was associated with a persistent reduction in neointimal thickening. The lack of effect of VCL on SMC proliferation suggests that the decrease in neointimal thickening may have been mediated through inhibition of SMC migration and/or modulation of the extracellular matrix.
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MESH Headings
- Angioplasty, Balloon/adverse effects
- Animals
- Femoral Artery/injuries
- Femoral Artery/pathology
- Male
- Microscopy, Electron, Scanning
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/ultrastructure
- Peptide Fragments/pharmacology
- Platelet Adhesiveness/drug effects
- Platelet Glycoprotein GPIb-IX Complex
- Platelet Membrane Glycoproteins/antagonists & inhibitors
- Rats
- Rats, Sprague-Dawley
- Receptors, Antigen, B-Cell/antagonists & inhibitors
- Receptors, Cell Surface/antagonists & inhibitors
- Recombinant Proteins/pharmacology
- Tunica Intima/drug effects
- Tunica Intima/ultrastructure
- von Willebrand Factor/pharmacology
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Affiliation(s)
- D Zahger
- Division of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
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41
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Meyer SC, Fox JE. Interaction of platelet glycoprotein V with glycoprotein Ib-IX regulates expression of the glycoproteins and binding of von Willebrand factor to glycoprotein Ib-IX in transfected cells. J Biol Chem 1995; 270:14693-9. [PMID: 7782333 DOI: 10.1074/jbc.270.24.14693] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The goal of the present study was to determine whether platelet glycoprotein (GP) V interacts directly with the von Willebrand factor receptor GP Ib-IX and, if so, whether it affects the expression and function of this receptor. A melanoma cell line that does not contain actin-binding protein was transfected with the cDNAs coding for GP V and for each of the three subunits of GP Ib-IX. GP V co-immunoprecipitated and co-localized with GP Ib-IX. Although GP V could be expressed in the absence of GP Ib-IX, the amount incorporated in the membrane was markedly increased when GP Ib-IX was present. Similarly, there was an enhanced expression of GP Ib-IX on the cell surface in the presence of GP V. The binding affinity of botrocetin-induced von Willebrand factor to GP Ib-IX was unaffected by the presence or absence of GP V. However, the binding capacity was increased by the presence of GP V. We conclude that GP V interacts directly with GP Ib-IX, that GP V must associate with GP Ib-IX to be efficiently expressed in the membrane, and that GP V increases the binding capacity of the cells for von Willebrand factor by enhancing the surface expression of the GP Ib-IX complex.
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Affiliation(s)
- S C Meyer
- Children's Hospital Oakland Research Institute, California 94609, USA
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42
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Abstract
Giant platelet disorders (GPD) refer to rare, usually inherited states characterized by abnormally large platelets, thrombocytopenia and bleeding tendency of variable severity. This review summarizes major clinical and laboratory features of three GPDs (Bernard-Soulier syndrome, May-Hegglin anomaly and gray platelet syndrome). Differential diagnosis between immunological thrombocytopenia and GPDs is important. Although rare, giant platelet disorders should be borne in mind, since bleeding tendency in some individuals may be severe and knowledge of bleeding diathesis is of importance before delivery or surgical procedures also in less symptomatic individuals.
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Affiliation(s)
- E Jantunen
- Department of Medicine, Kuopio University Hospital, Finland
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43
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Structural characterization and chromosomal location of the gene encoding human platelet glycoprotein Ib beta. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)32456-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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44
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Abstract
Although platelets stored by cryopreservation are effective in hemostasis, they acquire a number of functional defects during storage and preparation for transfusion. In addition to known acquired defects such as defective aggregation, decreased resistance to hypotonic shock, and disc-spherocyte transformation, we have shown that cryopreserved platelets have decreased capacity to adhere to subendothelium, compared to liquid-stored platelets. To investigate this decrease in adhesive capacity of cryopreserved platelets, we measured the major adhesive membrane glycoprotein, GPIb, and the principal aggregatory protein, GPIIb/IIIa, using flow cytometry in fresh platelets or in platelets cryopreserved in 5% DMSO. We also analyzed aggregation of cryopreserved platelets or liquid-stored platelets in response to ristocetin as another measurement of GPIb functional capacity. We found that approximately 15% of cryopreserved platelets lost surface-bound GPIb, while there was no measurable loss of GPIIB/IIIa during cryopreservation. The cryopreserved platelets also showed a significant decrease in aggregation to ristocetin, but no loss of response to the stronger agonist, thrombin. The loss of surface GPIb from cryopreserved platelets was modest in degree, approximately that reported for liquid-stored platelets, and does not seem great enough to account for the observed functional changes in aggregation and adhesion.
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Affiliation(s)
- M Owens
- Eastern Virginia Medical School, Department of Medicine, Norfolk
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45
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Tomer A, Scharf RE, McMillan R, Ruggeri ZM, Harker LA. Bernard-Soulier syndrome: quantitative characterization of megakaryocytes and platelets by flow cytometric and platelet kinetic measurements. Eur J Haematol Suppl 1994; 52:193-200. [PMID: 8005229 DOI: 10.1111/j.1600-0609.1994.tb00645.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Platelets and megakaryocytes have been characterized in a Bernard-Soulier syndrome (BSS) kindred with respect to glycoprotein (GP) membrane receptors and measurements of thrombocytopoiesis. The index patient exhibited lifelong bleeding tendency, moderate thrombocytopenia (35 x 10(9)/l), giant platelets (mean platelet volume 12.5 microns 3 compared to 7.5 +/- 1.5 microns 3 in normals), absent ristocetin-induced platelet agglutination and absent binding of von Willebrand factor (vWF). Flow-cytometric analysis revealed absent platelet binding (0-2%) of monoclonal antibodies (mAb, LJ-P3, LJ-Ib1 and LJ-Ib10) directed against distinct epitopes on membrane GPIb alpha of the GPIb-IX complex, and normal binding of LJ-P4 mAb directed against GPIIb/IIIa complex (relative to increased platelet surface area). Marrow megakaryocytes also failed to express GPIb-IX complex, but demonstrated normal expression of GPIIb/IIIa. Among 6 asymptomatic family members, the patient's mother and 2 of his 4 children exhibited approximately 50% binding of anti-GPIb alpha mAb to their platelets by both flow cytometry and direct binding studies using 125I-vWF, 125I-LJ-Ib1 and 125I-LJ-Ib10 mAb. Marrow megakaryocytes were increased in the average cell volume and cytoplasmic granularity with a corresponding increase in ploidy (46% > 16N compared to 22 +/- 5% in normal individuals), a pattern typical of megakaryocytes stimulated by thrombocytopenia. Autologous 111In-platelet life span was shortened to 4.1 days (compared with 9.5 +/- 0.5 days in normal subjects), and the turnover of platelet mass in the circulation was near normal. The data directly demonstrate that the platelet membrane GPIb-IX defect in BSS originates in megakaryocytes at all levels of cell maturation, and exclude the possibility that the receptor abnormality is acquired during cell maturation or after platelets are released into the circulation. Since marrow megakaryocytes exhibited cellular changes consistent with stimulated megakaryocytopoiesis, these results also suggest that thrombocytopenia in this kindred of BSS is a consequence of both decreased platelet survival and ineffective platelet production.
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Affiliation(s)
- A Tomer
- Division of Hematology and Oncology, Emory University School of Medicine, Atlanta, GA 30322
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46
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Swords NA, Tracy PB, Mann KG. Intact platelet membranes, not platelet-released microvesicles, support the procoagulant activity of adherent platelets. ARTERIOSCLEROSIS AND THROMBOSIS : A JOURNAL OF VASCULAR BIOLOGY 1993; 13:1613-22. [PMID: 8218102 DOI: 10.1161/01.atv.13.11.1613] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The possibility that platelets release microvesicles on adherence to either von Willebrand factor (vWf) or collagen was examined by flow cytometry analysis of the supernatant above layers of adherent platelets. No microvesicle release was detected as a result of adherence to vWf or to collagen, a known platelet agonist. Approximately 8% of the total platelet mass was released as microvesicles after thrombin stimulation of the vWf- or collagen-adherent platelets. A larger portion of the vWf-adherent platelet membranes (approximately 21%) was released as microvesicles subsequent to platelet stimulation with the nonphysiological agonist calcium ionophore A23187. Calpeptin, a calpain inhibitor, had no effect on microvesicle release, suggesting that calpain proteolysis of platelet cytoskeletal proteins was not responsible for microvesicle shedding under the conditions studied. Examination of the vWf-adherent platelets by scanning electron microscopy showed that virtually no microvesicles bound to exposed vWf multimers. No microvesicle binding to the adherent platelets was observed, indicating that the majority of the microvesicles were shed from the platelet and vWf surface on platelet activation. The ability of the microvesicle population to support procoagulant activity was measured with a prothrombinase activity assay and was compared with the activity supported by the adherent platelet membranes. More than 85% of the total prothrombinase activity remained associated with the adherent platelet membranes, both for unstimulated platelets and platelets stimulated with physiological agonists. Furthermore, the residual activity found in the buffer fraction containing detached platelets and any released microvesicles could be attributed to the detached platelets. No activity could be attributed to the microvesicles, as thrombin stimulation of either vWf-or collagen-adherent platelets did not promote increased procoagulant activity relative to the unstimulated adherent platelets, even though microvesicle release was detected as a result of agonist addition. Neither full platelet activation nor microvesicle shedding played an essential role in generating procoagulant activity in the adherent platelet system.
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Affiliation(s)
- N A Swords
- Department of Biochemistry, College of Medicine, University of Vermont, Burlington 05405
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47
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Swords NA, Mann KG. The assembly of the prothrombinase complex on adherent platelets. ARTERIOSCLEROSIS AND THROMBOSIS : A JOURNAL OF VASCULAR BIOLOGY 1993; 13:1602-12. [PMID: 8218101 DOI: 10.1161/01.atv.13.11.1602] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Prothrombinase complex assembly, in real time, on platelets adherent to immobilized von Willebrand Factor (vWf) was examined by total internal reflection fluorescence spectroscopy (TIRFS). Electron microscopy showed that the platelets adhered to vWf in a largely unactivated state and could be activated by thrombin. Antibody binding to glycoprotein (GP) Ib and functional GPIIb-IIIa receptor molecules on adherent platelet membranes monitored by TIRFS also indicated that platelets adhered in a largely unactivated state. Maximal expression of the receptor form of GPIIb-IIIa detected by antibody binding was seen only after thrombin stimulation of the adherent platelets. Antibody binding to GPIb was detected on adherent platelets. A reduction in antibody binding was observed after thrombin stimulation of the platelets, indicating a change in GPIb as a consequence of thrombin stimulation of the platelets. The binding of the protein components of the prothrombinase complex to adherent and thrombin-stimulated adherent platelets was then studied individually. Factor Va bound to adherent and thrombin-stimulated adherent platelets was then studied individually. Factor Va bound to adherent and thrombin-stimulated adherent platelets with an estimated Kd of 58 nmol/L. Minimal factor Xa binding was observed on adherent platelets before thrombin stimulation. Factor Xa binding was, however, readily observed on thrombin-stimulated adherent platelets. This factor Xa binding was not saturable, and no Kd value could be estimated. Direct measurement of prothrombinase complex assembly was demonstrated by using an energy transfer phenomenon between fluorescein-labeled factor Va and rhodamine-labeled factor Xa. Prothrombinase complex assembly was observed on both adherent and thrombin-stimulated adherent platelets. The estimated Kd for the factor Va/factor Xa interaction was 4 nmol/L. TIRFS demonstrated that adherent platelets have the ability to support prothrombinase complex assembly, as shown by a direct energy transfer reaction between fluorescently labeled factors Va and Xa.
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Affiliation(s)
- N A Swords
- Department of Biochemistry, College of Medicine, University of Vermont, Burlington 05405
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48
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Scanning electron microscopic study of the adhesion of a human megakaryocytic leukemia cell line (CMK11-5). Med Mol Morphol 1993. [DOI: 10.1007/bf02348032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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49
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Hickey MJ, Hagen FS, Yagi M, Roth GJ. Human platelet glycoprotein V: characterization of the polypeptide and the related Ib-V-IX receptor system of adhesive, leucine-rich glycoproteins. Proc Natl Acad Sci U S A 1993; 90:8327-31. [PMID: 7690959 PMCID: PMC47349 DOI: 10.1073/pnas.90.18.8327] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Human platelet glycoprotein (GP) V (M(r) 83,300), whose primary structure is reported here, is a part of the Ib-V-IX system of surface glycoproteins (GPs Ib alpha, Ib beta, V, IX) that constitute the receptor for von Willebrand factor (vWf) and mediate the adhesion of platelets to injured vascular surfaces in the arterial circulation, a critical initiating event in hemostasis. System members share physical associations, leucine-rich glycoprotein (LRG) structures, and a congenital deficiency state, Bernard-Soulier syndrome. With PCR techniques and platelet cDNA templates, 1.4 kb of GP V cDNA sequence was obtained that encodes 469 GP V amino acids. A genomic 3.5-kb BamHI fragment was then isolated that includes 3.46 kb of GP V cDNA sequence: the 1.7-kb open reading frame plus 2 bases of the 5' and 1.8 kb of the 3' untranslated regions. Northern blot analysis reveals three GP V platelet transcripts of 3.8, 4.2, and 5.2 kb. A 16-amino acid signal peptide is present. Mature GP V is a 544-amino acid transmembrane protein with a 504-amino acid extracellular domain that encompasses a set of 15 tandem LRG repeats in a "flank-LRG center-flank" array [Roth, G. J. (1991) Blood 77, 5-19] along with eight putative N-linked glycosylation sites and cleavage sites for thrombin and calpain. GP V is a transmembrane, adhesive LRG protein that plays an undefined, but potentially critical, role in the expression and/or function of the Ib-V-IX receptor for vWf/shear-dependent platelet adhesion in arteries.
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Affiliation(s)
- M J Hickey
- Hematology Section, Seattle Veterans Administration Medical Center, WA 98105
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50
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Expression and characterization of functionally active fragments of the platelet glycoprotein (GP) Ib-IX complex in mammalian cells. Incorporation of GP Ib alpha into the cell surface membrane. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(20)80761-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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