Deutsch Varda R, Tomer Aaron
The Haematology Institute, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel.
Br J Haematol. 2006 Sep;134(5):453-66. doi: 10.1111/j.1365-2141.2006.06215.x.
Megakaryocytopoiesis involves the commitment of haematopoietic stem cells, and the proliferation, maturation and terminal differentiation of the megakaryocytic progenitors. Circulating levels of thrombopoietin (TPO), the primary growth-factor for the megakaryocyte (MK) lineage, induce concentration-dependent proliferation and maturation of MK progenitors by binding to the c-Mpl receptor and signalling induction. Decreased platelet turnover rates results in increased concentration of free TPO, enabling the compensatory response of marrow MKs to increased platelet production. C-Mpl activity is orchestrated by a complex cascade of signalling molecules that induces the action of specific transcription factors to drive MK proliferation and maturation. Mature MKs form proplatelet projections that are fragmented into circulating particles. Newly developed thrombopoietic agents operating via c-Mpl receptor may prove useful in supporting platelet production in thrombocytopenic state. Herein, we review the regulation of megakaryocytopoiesis and platelet production in normal and disease state, and the new approaches to thrombopoietic therapy.
巨核细胞生成涉及造血干细胞的定向分化,以及巨核细胞祖细胞的增殖、成熟和终末分化。血小板生成素(TPO)是巨核细胞(MK)谱系的主要生长因子,其循环水平通过与c-Mpl受体结合并诱导信号传导,从而诱导MK祖细胞进行浓度依赖性增殖和成熟。血小板周转率降低会导致游离TPO浓度升高,从而使骨髓MKs对血小板生成增加产生代偿反应。c-Mpl活性由一系列复杂的信号分子级联调控,这些信号分子诱导特定转录因子的作用,以驱动MK增殖和成熟。成熟的MKs形成前血小板突起,这些突起会断裂成循环颗粒。新开发的通过c-Mpl受体起作用的血小板生成剂可能在支持血小板减少状态下的血小板生成方面证明是有用的。在此,我们综述了正常和疾病状态下巨核细胞生成和血小板生成的调节,以及血小板生成治疗的新方法。