Coated platelets function in platelet-dependent fibrin formation via integrin αIIbβ3 and transglutaminase factor XIII

• Published in: Haematologica (Roma) Vol. 101; no. 4; pp. 427 - 436
• Main Authors: Mattheij, Nadine J A, Swieringa, Frauke, Mastenbroek, Tom G, Berny-Lang, Michelle A, May, Frauke, Baaten, Constance C F M J, van der Meijden, Paola E J, Henskens, Yvonne M C, Beckers, Erik A M, Suylen, Dennis P L, Nolte, Marc W, Hackeng, Tilman M, McCarty, Owen J T, Heemskerk, Johan W M, Cosemans, Judith M E M
• Format: Journal Article
• Language: English
• Published: Italy Ferrata Storti Foundation 01.04.2016
• Subjects: Animals; Blood Coagulation; Blood Platelets - drug effects; Blood Platelets - metabolism; Blood Platelets - pathology; Crotalid Venoms - pharmacology; Factor Va - chemistry; Factor Va - metabolism; Factor Xa - chemistry; Factor Xa - metabolism; Factor XIII - chemistry; Factor XIII - metabolism; Fibrin - chemistry; Fibrin - metabolism; Fibrinogen - chemistry; Fibrinogen - metabolism; Humans; Lectins, C-Type; Mice; Mice, Knockout; Molecular Probes - chemistry; Phosphatidylserines - chemistry; Phosphatidylserines - metabolism; Platelet Activation - drug effects; Platelet Glycoprotein GPIIb-IIIa Complex - chemistry; Platelet Glycoprotein GPIIb-IIIa Complex - metabolism; Primary Cell Culture; Protein Binding; Thrombasthenia - blood; Thrombasthenia - pathology; Thrombin - pharmacology
• ISSN: 1592-8721; 0390-6078; 1592-8721
• DOI: 10.3324/haematol.2015.131441

Coated platelets, formed by collagen and thrombin activation, have been characterized in different ways: i) by the formation of a protein coat of α-granular proteins; ii) by exposure of procoagulant phosphatidylserine; or iii) by high fibrinogen binding. Yet, their functional role has remained unclear. Here we used a novel transglutaminase probe, Rhod-A14, to identify a subpopulation of platelets with a cross-linked protein coat, and compared this with other platelet subpopulations using a panel of functional assays. Platelet stimulation with convulxin/thrombin resulted in initial integrin α(IIb)β3 activation, the appearance of a platelet population with high fibrinogen binding, (independently of active integrins, but dependent on the presence of thrombin) followed by phosphatidylserine exposure and binding of coagulation factors Va and Xa. A subpopulation of phosphatidylserine-exposing platelets bound Rhod-A14 both in suspension and in thrombi generated on a collagen surface. In suspension, high fibrinogen and Rhod-A14 binding were antagonized by combined inhibition of transglutaminase activity and integrin α(IIb)β3 Markedly, in thrombi from mice deficient in transglutaminase factor XIII, platelet-driven fibrin formation and Rhod-A14 binding were abolished by blockage of integrin α(IIb)β3. Vice versa, star-like fibrin formation from platelets of a patient with deficiency in α(IIb)β3(Glanzmann thrombasthenia) was abolished upon blockage of transglutaminase activity. We conclude that coated platelets, with initial α(IIb)β3 activation and high fibrinogen binding, form a subpopulation of phosphatidylserine-exposing platelets, and function in platelet-dependent star-like fibrin fiber formation via transglutaminase factor XIII and integrin α(IIb)β3.