Polarization and Migration of Hematopoietic Stem and Progenitor Cells Rely on the RhoA/ROCK I Pathway and an Active Reorganization of the Microtubule Network
Polarization and Migration of Hematopoietic Stem and Progenitor Cells Rely on the RhoA/ROCK I Pathway and an Active Reorganization of the Microtubule Network
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DOI：
10.1074/jbc.m110.145037
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发表时间：
2010-10-08
影响因子：
4.8
通讯作者：
Corbeil, Denis
中科院分区：
文献类型：
--
作者：
Fonseca, Ana-Violeta;Freund, Daniel;Corbeil, Denis
了解造血祖细胞的生理迁移是很重要的，不仅是基础的干细胞研究，而且鉴于其治疗相关性。在这里，我们研究了Rho激酶通路的造血祖细胞的形态和迁移的作用，使用体外共培养的人原代CD 34（+）祖细胞和间充质基质细胞。Rho激酶抑制剂Y-27632的加入导致造血祖细胞的尾足和微绒毛样结构的废除，伴随着其中发现的蛋白质（Ezrin-1和ezrin）的重新分布。Y-27632处理的细胞表现出迁移缺陷。延时视频显微镜检查显示后极回缩受损。有趣的是，使用RNA干扰（RNAi）敲低ROCK I而非ROCK II足以引起所提及的形态学和迁移变化。出乎意料的是，向Y-27632或ROCK I RNAi处理的细胞中加入诺考达唑可以恢复它们的极化形态和迁移，这表明微管网络在尾收缩中起积极作用。最后，我们可以使用RNAi证明ROCK的上游调节因子RhoA参与了这些过程。总的来说，我们的数据提供了关于RhoA/ROCK I和微管在干细胞迁移中的作用的新见解。
Understanding the physiological migration of hematopoietic progenitors is important, not only for basic stem cell research, but also in view of their therapeutic relevance. Here, we investigated the role of the Rho kinase pathway in the morphology and migration of hematopoietic progenitors using an ex vivo co-culture consisting of human primary CD34(+) progenitors and mesenchymal stromal cells. The addition of the Rho kinase inhibitor Y-27632 led to the abolishment of the uropod and microvillar-like structures of hematopoietic progenitors, concomitant with a redistribution of proteins found therein (prominin-1 and ezrin). Y-27632-treated cells displayed a deficiency in migration. Time-lapse video microscopy revealed impairment of the rear pole retraction. Interestingly, the knockdown of ROCK I, but not ROCK II, using RNA interference (RNAi) was sufficient to cause the referred morphological and migrational changes. Unexpectedly, the addition of nocodazole to either Y-27632- or ROCK I RNAi-treated cells could restore their polarized morphology and migration suggesting an active role for the microtubule network in tail retraction. Finally, we could demonstrate using RNAi that RhoA, the upstream regulator of ROCK, is involved in these processes. Collectively, our data provide new insights regarding the role of RhoA/ROCK I and the microtubules in the migration of stem cells.