Thrombopoietin, c‐Mpl ligand, induces tyrosine phosphorylation of Tyk2, JAK2, and STAT3, and enhances agonists‐induced aggregation in platelets in vitro

FEBS Letters

Takayama, Hiroshi¹  Okuma, Minoru¹  Ezumi, Yasuharu¹ 

[1] First Division, Department of Internal Medicine, Faculty of Medicine, Kyoto University, 54 Shogoin-Kawaramachi, Sakyo-ku, Kyoto 606, Japan

关键词: Thrombopoietin;    Signal transduction;    Protein-tyrosine kinase;    Transcription factor;    Platelet aggregation;    Adenosine diphosphate;    TPO;    thrombopoietin;    JAK;    Janus tyrosine kinase;    ASA;    acetylsalicylic acid or aspirin;    PRP;    platelet-rich plasma;    STAT;    signal transducers and activators of transcription;   

DOI  :  10.1016/0014-5793(95)01072-M

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We investigated in vitro effects of recombinant human thrombopoietin (TPO), or c-Mpl ligand, on human platelets. TPO induced rapid dose-dependent tyrosine phosphorylation of several proteins. We identified Janus tyrosine kinases, Tyk2 and JAK2, and a member of STAT (signal transducers and activators of transcription) family, STAT3, as the tyrosine-phosphorylated proteins in response to TPO. TPO by itself did not cause platelet aggregation and shape change, but augmented ADP-induced aggregation in a dose-dependent manner. Acetylsalicylic acid inhibited the secondary aggregation enhanced by TPO, but not the TPO-induced potentiation of the primary aggregation. TPO modulates platelet activation possibly through protein-tyrosine phosphorylation.

【 授权许可】

Unknown