title: Thrombopoietin-induced Dami cells as a model for alpha-granule biogenesis.
abstract: Megakaryocytic alpha-granules contain secretory proteins relevant to megakaryocyte and platelet functions. Understanding alpha-granule biogenesis is hampered because human primary megakaryocytes are difficult to manipulate. Existing promegakaryocytic cell lines do not spontaneously exhibit mature alpha-granules. Dami cells, transfected with the megakaryocytic platelet factor 4, fused to GFP (PF4-GFP), were induced in the presence of thrombopoietin (TPO), a megakaryocyte cytokine and PMA. Using confocal microscopy, PF4-GFP colocalized with von Willebrand Factor (vWF) in newly formed storage granules. Immunoelectron microscopy demonstrated alpha-granule-like features, including a dense core or parallel tubules and colocalization of PF4-GFP and vWF. Hence, TPO-treated Dami cells are a suitable model to study alpha-granules and their biogenesis.
authors.affiliation: U348 INSERM, IFR6-Circulation, Hôpital Lariboisière, Paris, France. veronique.briquet-laugier@larib.inserm.fr
authors.forename: Véronique
authors.initials: V
authors.lastname: Briquet-Laugier
authors.forename: Nargès
authors.initials: N
authors.lastname: El Golli
authors.forename: Paquita
authors.initials: P
authors.lastname: Nurden
authors.forename: Cécile
authors.initials: C
authors.lastname: Lavenu-Bombled
authors.forename: Anne
authors.initials: A
authors.lastname: Dubart-Kupperschmitt
authors.forename: Alan
authors.initials: A
authors.lastname: Nurden
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Rosa
mesh_terms: D002451:Cell Compartmentation / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003594:Cytoplasmic Granules / Q000187:drug effects / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D008533:Megakaryocytes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D018613:Microscopy, Confocal; D016253:Microscopy, Immunoelectron; D010978:Platelet Factor 4 / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013926:Thrombopoietin / Q000502:physiology*; D014842:von Willebrand Diseases / Q000097:blood
chemical_list: D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D010978:Platelet Factor 4; D013926:Thrombopoietin; D013755:Tetradecanoylphorbol Acetate