A genetic modifier of venous thrombosis in zebrafish reveals a functional role for fibrinogen AαE in early hemostasis

Article Article scientifique Article A genetic modifier of venous thrombosis in zebrafish reveals a functional role for fibrinogen AαE in early hemostasis eng 2020 author Freire Cristina 846808 author Fish Richard 0000-0003-2830-4260 133844 author Ferreira Vilar Da Silva Rui Filipe 843527 author Di Sanza Corinne 23232 author Grzegorski Steven J author Richter Catherine E author Shavit Jordan A author Neerman Arbez Marguerite 0000-0002-9351-4195 27647 5480-5491 10.1182/bloodadvances.2020001472 33166405 2473-9529 Plasma fibrinogen molecules comprise 2 copies of Aα, Bβ, and γ chains folded into a hexameric protein. A minor fibrinogen isoform with an extended Aα chain (AαE) is more abundant in newborn human blood than in adults. Larval zebrafish produce predominantly AαE-containing fibrinogen, but its functional significance is unclear. In 3-day-old zebrafish, when hemostasis is reliant on fibrinogen and erythrocyte-rich clotting but is largely thrombocyte-independent, we measured the time to occlusion (TTO) in a laser-induced venous thrombosis assay in 3 zebrafish strains (AB, TU, and AB × TL hybrids). AB larvae showed delayed TTO compared with the TU and AB × TL strains. Mating AB with TU or TL produced larvae with a TU-like TTO. In contrast to TU, AB larvae failed to produce fibrinogen AαE, due to a mutation in the AαE-specific coding region of fibrinogen α-chain gene (fga). We investigated whether the lack of AαE explained the delayed AB TTO. Transgenic expression of AαE, but not Aα, shortened the AB TTO to that of TU. AαE rescued venous occlusion in fibrinogen mutants or larvae with morpholino-targeted fibrinogen α-chain messenger RNA, but Aα was less effective. In 5-day-old larvae, circulating thrombocytes contribute to hemostasis, as visualized in Tg(itga2b:EGFP) transgenics. Laser-induced venous thrombocyte adhesion and aggregation is reduced in fibrinogen mutants, but transgenic expression of Aα or AαE restored similar thrombocyte accumulation at the injury site. Our data demonstrate a genetic modifier of venous thrombosis and a role for fibrinogen AαE in early developmental blood coagulation, and suggest a link between differentially expressed fibrinogen isoforms and the cell types available for clotting. Adult Animals Fibrinogen/genetics Hemostasis Hemostatics Humans Infant Newborn Venous Thrombosis Zebrafish Dewey 576.5 Swiss National Science Foundation 310003A_152633 CH 135 Département de médecine génétique et développement 21D false 258 Recherche translationnelle : anomalies de l'hémostase et thromboses 504 Blood Advances 4 21 ffaf107c-0ef0-43ab-b9b8-e183f1783357 Article (Published version) Public advancesadv2020001472.pdf 2505998 application/pdf OA OTHER openAccess Faculté de médecine / Section de médecine fondamentale / Département de médecine génétique et développement

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A genetic modifier of venous thrombosis in zebrafish reveals a functional role for fibrinogen AαE in early hemostasis	Blood Advances			2020	220	284

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Freire, Cristina