miR-125a-5p regulates megakaryocyte proplatelet formation via the actin-bundling protein L-plastin
miR-125a-5p regulates megakaryocyte proplatelet formation via the actin-bundling protein L-plastin
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DOI：
10.1182/blood.2020005230
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发表时间：
2020-10-08
期刊：
影响因子：
20.3
通讯作者：
Bray, Paul F.
中科院分区：
文献类型：
--
作者：
Bhatlekar, Seema;Manne, Bhanu K.;Bray, Paul F.
血小板计数的个体差异具有遗传性，更好地了解调节遗传因素可能为血小板生成提供见解。 MicroRNA (miR) 调节健康和疾病中的基因表达，缺乏 miR 的巨核细胞 (MK) 血小板计数较低，但有关 miR 在正常人 MK 和血小板生成中的作用的信息有限。使用全基因组 miR 分析，我们观察到人类骨髓MK、血小板和分化脐带血来源的 MK 培养物之间的强相关性，并确定 MK miR-125a-5p 与人类血小板数量相关，但与白细胞或血红蛋白水平无关。过表达和敲低研究表明，miR-125a-5p 在体外正向调节人 MK 前血小板 (PP) 的形成。体内抑制 miR-125a-5p 会降低小鼠血小板计数。 MK 和血小板转录组分析确定 LCP1 是 miR-125a-5p 靶标。 LCP1 编码肌动蛋白捆绑蛋白 L-plastin，之前未在 MK 中进行过研究。我们发现 miR-125a-5p 直接靶向并降低 MK L-plastin 的表达。过表达和敲低研究表明，L-plastin 促进 MK 祖细胞迁移，但与人血小板计数呈负相关并抑制 MK PP 形成 (PPF)。这项工作为肌动蛋白捆绑蛋白 L-plastin 通过抑制晚期 MK 内陷系统、足体和 PPF 以及 PP 分支作为人类 MK PPF 的调节剂提供了第一个证据。我们还提供与血小板计数相关的初级和分化 MK 转录组和 miR 资源。 miR-125a-5p 和 L-plastin 可能是增加体外血小板生成和管理血小板数量紊乱的相关靶标。
There is heritability to interindividual variation in platelet count, and better understanding of the regulating genetic factors may provide insights for thrombopoiesis. MicroRNAs (miRs) regulate gene expression in health and disease, and megakaryocytes (MKs) deficient in miRs have lower platelet counts, but information about the role of miRs in normal human MK and platelet production is limited. Using genome-wide miR profiling, we observed strong correlations among human bonemarrowMKs, platelets, and differentiating cord blood-derived MK cultures, and identified MK miR-125a-5p as associated with human platelet number but not leukocyte or hemoglobin levels. Overexpression and knockdown studies showed that miR-125a-5p positively regulated human MK proplatelet (PP) formation in vitro. Inhibition of miR-125a-5p in vivo lowered murine platelet counts. Analyses of MK and platelet transcriptomes identified LCP1 as a miR-125a-5p target. LCP1 encodes the actin-bundling protein, L-plastin, not previously studied in MKs. We show that miR-125a-5p directly targets and reduces expression of MK L-plastin. Overexpression and knockdown studies show that L-plastin promotes MK progenitor migration, but negatively correlates with human platelet count and inhibits MK PP formation (PPF). This work provides the first evidence for the actin-bundling protein, L-plastin, as a regulator of human MK PPF via inhibition of the late-stage MK invagination system, podosome and PPF, and PP branching. We also provide resources of primary and differentiating MK transcriptomes and miRs associated with platelet counts. miR-125a-5p and L-plastin may be relevant targets for increasing in vitro platelet manufacturing and for managing quantitative platelet disorders.