title: Factor-V expression in platelets from human megakaryocytic culture.
abstract: The origin of platelet-factor-V has long been discussed. To elucidate whether and when human platelet-factor-V is synthesized by megakaryocytes, we utilized in vitro-generated megakaryocytes capable of producing platelets. Factor-V gene was silent in purified progenitors and megakaryocytic precursors but was expressed in late culture phase and maintained also in platelets. Similarly, factor-V protein was expressed in mature proplatelet-bearing megakaryocytes (immunofluorescence analysis); it was also detectable in cultured megakaryocytes and platelets (Western blotting) and within permeabilized cultured platelets (flow cytometry). The absence of other cells in our culture system indicates conclusively that human megakaryocytes synthesize factor-V.
authors.affiliation: Section of Transfusion Methodologies, Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Adele
authors.initials: A
authors.lastname: Giampaolo
authors.forename: Francesca
authors.initials: F
authors.lastname: Vulcano
authors.forename: Giampiero
authors.initials: G
authors.lastname: Macioce
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Mattia
authors.forename: Alessandra
authors.initials: A
authors.lastname: Barca
authors.forename: Luisa
authors.initials: L
authors.lastname: Milazzo
authors.forename: Carmela
authors.initials: C
authors.lastname: Ciccarelli
authors.forename: Hamisa J
authors.initials: HJ
authors.lastname: Hassan
mesh_terms: D001792:Blood Platelets / Q000378:metabolism*; D015153:Blotting, Western / Q000379:methods; D018929:Cell Culture Techniques; D005165:Factor V / Q000032:analysis* / Q000096:biosynthesis; D005434:Flow Cytometry; D006801:Humans; D008533:Megakaryocytes / Q000378:metabolism*; D013997:Time Factors
chemical_list: D005165:Factor V