The biogenesis of platelets from megakaryocyte proplatelets

Hematology Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
Journal of Clinical Investigation (Impact Factor: 13.22). 01/2006; 115(12):3348-54. DOI: 10.1172/JCI26891
Source: PubMed


Platelets are formed and released into the bloodstream by precursor cells called megakaryocytes that reside within the bone marrow. The production of platelets by megakaryocytes requires an intricate series of remodeling events that result in the release of thousands of platelets from a single megakaryocyte. Abnormalities in this process can result in clinically significant disorders. Thrombocytopenia (platelet counts less than 150,000/microl) can lead to inadequate clot formation and increased risk of bleeding, while thrombocythemia (platelet counts greater than 600,000/microl) can heighten the risk for thrombotic events, including stroke, peripheral ischemia, and myocardial infarction. This Review will describe the process of platelet assembly in detail and discuss several disorders that affect platelet production.

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    • "Megakaryopoiesis is a multistep process driving the proliferation, differentiation and maturation of hematopoietic stem cells to the generation of platelets, anucleate blood components with a fundamental role in the hemostatic process.1 "
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    • "They become polyploid (4–64 N) through several cycles of endomitosis [6] [7] [8]. In addition, a cytoplasmic maturation occurs involving the formation of a demarcation membrane system (DMS) and the accumulation of cytoplasmic proteins and secretory granules [6] [9]. "
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    • "We observed endomitosing megakaryoblasts in MPP, CMP and MEP cultures. In the MKC culture, we observed mature MKCs with red nuclei exhibiting hallmark features of proplatelets (supplementary material Fig. S6C, arrowhead) (Patel et al., 2005). We also examined nuclear structures during endomitosis in MKCs (Fig. 5C). "
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