Clinical and Translational Research Center, Keio University School of Medicine, Tokyo, Japan.
Department of Hematology, Keio University School of Medicine, Tokyo, Japan.
J Thromb Haemost. 2021 Feb;19(2):342-350. doi: 10.1111/jth.15181. Epub 2020 Dec 21.
Megakaryocytes (MKs) are platelet progenitor stem cells found in the bone marrow. Platelets obtained from blood draws can be used for therapeutic applications, especially platelet transfusion. The needs for platelet transfusions for clinical situation is increasing, due in part to the growing number of patients undergoing chemotherapy. Platelets obtained from donors, however, have the disadvantages of a limited storage lifespan and the risk of donor-related infection. Extensive effort has therefore been directed at manufacturing platelets ex vivo. Here, we review ex vivo technologies for MK development, focusing on human adipose tissue-derived mesenchymal stem/stromal cell line (ASCL)-based strategies and their potential clinical application. Bone marrow and adipose tissues contain mesenchymal stem/stromal cells that have an ability to differentiate into MKs, which release platelets. Taking advantage of this mechanism, we developed a donor-independent system for manufacturing platelets for clinical application using ASCL established from adipose-derived mesenchymal stem/stromal cells (ASCs). Culture of ASCs with endogenous thrombopoietin and its receptor c-MPL, and endogenous genes such as p45NF-E2 leads to MK differentiation and subsequent platelet production. ASCs compose heterogeneous cells, however, and are not suitable for clinical application. Thus, we established ASCLs, which expand into a more homogeneous population, and fulfill the criteria for mesenchymal stem cells set by the International Society for Cellular Therapy. Using our ASCL culture system with MK lineage induction medium without recombinant thrombopoietin led to peak production of platelets within 12 days, which may be sufficient for clinical application.
巨核细胞（MKs）是骨髓中血小板的祖细胞干细胞。从血液中提取的血小板可用于治疗应用，特别是血小板输注。由于接受化疗的患者数量不断增加，临床对血小板输注的需求也在增加。然而，从供体获得的血小板具有储存寿命有限和供体相关感染风险的缺点。因此，人们已经在广泛努力地在体外制造血小板。在这里，我们综述了体外 MK 发育的技术，重点介绍了基于人脂肪组织来源的间充质干细胞/基质细胞系（ASCL）的策略及其潜在的临床应用。骨髓和脂肪组织中含有间充质干细胞/基质细胞，它们具有分化为释放血小板的 MK 的能力。利用这一机制，我们利用从脂肪来源的间充质干细胞（ASCs）建立的 ASCL，开发了一种用于临床应用的、不依赖供体的血小板制造系统。ASCs 与内源性血小板生成素及其受体 c-MPL 以及内源性基因（如 p45NF-E2）共培养，可诱导 MK 分化和随后的血小板生成。然而，ASCs 组成异质细胞，不适合临床应用。因此，我们建立了 ASCL，其扩增为更同质的群体，并符合国际细胞治疗学会规定的间充质干细胞标准。使用我们的 ASCL 培养系统，在没有重组血小板生成素的 MK 谱系诱导培养基中培养 12 天即可达到血小板产量峰值，这可能足以满足临床应用的需要。
