title: Platelet glycoprotein VI binds to polymerized fibrin and promotes thrombin generation.
abstract: Fibrin, the coagulation end product, consolidates the platelet plug at sites of vascular injury and supports the recruitment of circulating platelets. In addition to integrin αIIbβ3, another as-yet-unidentified receptor is thought to mediate platelet interaction with fibrin. Platelet glycoprotein VI (GPVI) interacts with collagen and several other adhesive macromolecules. We evaluated the hypothesis that GPVI could be a functional platelet receptor for fibrin. Calibrated thrombin assays using platelet-rich plasma (PRP) showed that tissue factor-triggered thrombin generation was impaired in GPVI-deficient patients and reduced by the anti-GPVI Fab 9O12. Assays on reconstituted PRP and PRP from fibrinogen-deficient patients revealed a fibrinogen-dependent enhancement of thrombin generation, which relied on functional GPVI. The effect of GPVI was found to depend on fibrin polymerization. A binding assay showed a specific interaction between GPVI-Fc and fibrin, inhibited by the Fab 9O12. This Fab also reduced platelet adhesion to fibrin at low (300 s(-1)) and high (1500 s(-1)) wall shear rates. Platelets adherent to fibrin displayed shape change, exposure of procoagulant phospholipids, and the formation of small clots. When hirudinated blood was perfused at 1500 s(-1) over preformed fibrin-rich clots, the Fab 9O12 decreased the recruitment of platelets by up to 85%. This study identifies GPVI as a platelet receptor for polymerized fibrin with 2 major functions: (1) amplification of thrombin generation and (2) recruitment of circulating platelets to clots. These so-far-unrecognized properties of GPVI confer on it a key role in thrombus growth and stabilization.
authors.affiliation: Unités Mixtes de Recherche S949, INSERM, Strasbourg, France; Etablissement Français du Sang-Alsace, Strasbourg, France; Université de Strasbourg, Strasbourg, France; Fédération de Médecine Translationnelle de Strasbourg, Strasbourg, France;
authors.forename: Elmina
authors.initials: E
authors.lastname: Mammadova-Bach
authors.affiliation: Unité Mixte de Recherche S1148, INSERM, Paris, France; Université Paris Diderot, Paris, France; Centre Hospitalier Universitaire Bichat, Paris, France;
authors.forename: Véronique
authors.initials: V
authors.lastname: Ollivier
authors.affiliation: Unité Mixte de Recherche S1148, INSERM, Paris, France; Université Paris Diderot, Paris, France; Centre Hospitalier Universitaire Bichat, Paris, France;
authors.forename: Stéphane
authors.initials: S
authors.lastname: Loyau
authors.affiliation: Unités Mixtes de Recherche S949, INSERM, Strasbourg, France; Etablissement Français du Sang-Alsace, Strasbourg, France; Université de Strasbourg, Strasbourg, France; Fédération de Médecine Translationnelle de Strasbourg, Strasbourg, France;
authors.forename: Mathieu
authors.initials: M
authors.lastname: Schaff
authors.affiliation: Unité Mixte de Recherche S1148, INSERM, Paris, France; Université Paris Diderot, Paris, France; Centre Hospitalier Universitaire Bichat, Paris, France;
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Dumont
authors.affiliation: Centre Hospitalier Universitaire Paris Est-Hôpital d'Enfants Armand-Trousseau, Paris, France;
authors.forename: Rémi
authors.initials: R
authors.lastname: Favier
authors.affiliation: Laboratoire d'Hématologie, Hôpital Pellegrin, Bordeaux, France;
authors.forename: Geneviève
authors.initials: G
authors.lastname: Freyburger
authors.affiliation: Service d'Hématologie Biologique, University Hospital of Nancy, Nancy, France; and.
authors.forename: Véronique
authors.initials: V
authors.lastname: Latger-Cannard
authors.affiliation: Vascular Medicine, University Hospital Wuerzburg and Rudolf Virchow Center for Experimental Biomedicine, Wuerzburg, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Nieswandt
authors.affiliation: Unités Mixtes de Recherche S949, INSERM, Strasbourg, France; Etablissement Français du Sang-Alsace, Strasbourg, France; Université de Strasbourg, Strasbourg, France; Fédération de Médecine Translationnelle de Strasbourg, Strasbourg, France;
authors.forename: Christian
authors.initials: C
authors.lastname: Gachet
authors.affiliation: Unités Mixtes de Recherche S949, INSERM, Strasbourg, France; Etablissement Français du Sang-Alsace, Strasbourg, France; Université de Strasbourg, Strasbourg, France; Fédération de Médecine Translationnelle de Strasbourg, Strasbourg, France;
authors.forename: Pierre H
authors.initials: PH
authors.lastname: Mangin
authors.affiliation: Unité Mixte de Recherche S1148, INSERM, Paris, France; Université Paris Diderot, Paris, France; Centre Hospitalier Universitaire Bichat, Paris, France;
authors.forename: Martine
authors.identifier: http://orcid.org/0000-0002-8450-9247
authors.initials: M
authors.lastname: Jandrot-Perrus
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000378:metabolism; D016022:Case-Control Studies; D003094:Collagen / Q000378:metabolism; D005337:Fibrin / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D010973:Platelet Adhesiveness; D010980:Platelet Membrane Glycoproteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D058105:Polymerization; D011485:Protein Binding; D013917:Thrombin / Q000096:biosynthesis*; D013927:Thrombosis / Q000097:blood / Q000209:etiology
chemical_list: D010980:Platelet Membrane Glycoproteins; C098341:platelet membrane glycoprotein VI; D005337:Fibrin; D003094:Collagen; D013917:Thrombin