Thrombopoietin modulates platelet activation in vitro through protein-tyrosine phosphorylation.
Stem Cells
; 14(4): 439-44, 1996 Jul.
Article
em En
| MEDLINE
| ID: mdl-8843545
ABSTRACT
To determine the roles of thrombopoietin (TPO) in platelet function in vitro, we examined the effects of TPO on platelet aggregation. Although several proteins in platelets were tyrosine-phosphorylated by TPO treatment, TPO alone was unable to induce platelet aggregation. However, the secondary wave of platelet aggregation induced by adenosine diphosphate (ADP) was enhanced by TPO in a dose-dependent manner. TPO in conjunction with ADP augmented tyrosine phosphorylation of platelet proteins, including tyrosine-phosphorylated proteins induced by TPO alone. Genistein inhibited protein-tyrosine phosphorylation in platelets induced by TPO with ADP and suppressed TPO-enhanced platelet aggregation. Moreover, tyrosine phosphorylation of MAP-kinases induced by TPO alone and TPO with ADP was consistent with TPO-enhanced platelet aggregation. These findings in the present study suggest that signal transduction involved in TPO-enhanced platelet aggregation is mediated in part by tyrosine-phosphorylated proteins, including MAP-kinases, in platelets through TPO-stimulated c-Mpl, TPO receptor.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Trombopoetina
/
Tirosina
/
Plaquetas
/
Difosfato de Adenosina
/
Agregação Plaquetária
Limite:
Humans
Idioma:
En
Revista:
Stem Cells
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Japão