Biological analysis of signal transduction of Rho-Rho kinase

在这个项目的过程中，我们阐明了分子开关Rho-ROCK信号的三个新功能。首先，我们与大阪大学医学院骨科教授吉川博士合作，发现岩石抑制剂促进了骨形态发生蛋白(BMP)诱导的骨形成，而不影响动物的骨代谢。利用几个未分化的间充质细胞系，发现Rho-ROCK信号负性调节BMP的表达，因此ROCK抑制剂释放这种抑制，从而促进成骨细胞的分化。我们进一步分析了成骨细胞分化的信号，发现MEK-MAPK信号也负调控成骨信号，MEK1的特异性抑制剂(PD98059)在体外和体内都促进骨形成(6)。这些结果的临床应用的未来研究目前正在进行中。其次，与西班牙…合作更多的教授桑切斯马德里博士，我们分析了趋化因子(sdf-1α)诱导的淋巴细胞趋化信号，发现Rho-Rock-myosin(分子马达)信号在这种迁移中起着关键作用，类似于我们之前已经报道的癌症侵袭。我们还发现，Rho-ROCK信号涉及使用相同系统的淋巴细胞的微管动力学(5)。由于淋巴细胞迁移是免疫反应的关键，我们的结果为通过调节淋巴细胞迁移来控制免疫反应开辟了一个新的领域。最后，与九州大学的Nishimura博士合作，我们发现Rho-ROCK信号通过改变微管动力学来控制溶酶体囊泡的运输(1，7)。细胞内转运机制是目前研究的热点，因为它调节细胞功能的数量，是临床治疗的最佳分子靶点之一。我们的结果揭示了Rho-Rock诱导的细胞骨架改变在囊泡运输中的关键作用，以及这种系统在治疗包括毁灭性癌症在内的多种疾病中的药理操作。较少

During the course of this project, we elucidated the three novel function of molecular switch Rho-ROCK signaling. Firstly, collaborating with orthopedic professor Dr. Yoshikawa, Osaka University medical school, we found that the inhibitor for ROCK accelerate the bone formation induced by bone morphogenetic protein (BMP) without affecting the bone metabolism in animal. Employing several undifferentiated mesenchymal cell lines, it revealed that Rho-ROCK signaling negatively regulated the expression of BMP, thus the ROCK inhibitor released such inhibition leading to the enhancement of osteoblastic differentiation (3). We further analyzed the signaling of osteoblastic differentiation and found that MEK-MAPK signaling also negatively regulated the osteoblastic signaling, and that the specific inhibitor for MEK1 (PD98059) enhanced bone formation both in vitro and in vivo (6). Future study for clinical application for these results is currently undertaken. Secondary, collaborating with Spanis … More h professor Dr. Sanchez Madrid, we analyzed the signaling for chemokine (SDF-1α)-induced lymphocyte chemotaxis and found that Rho-ROCK-myosin (molecular motor) signaling plays a pivotal role for that migration similar to that of cancer invasion, which we have already reported previously. We also found that Rho-ROCK signaling involved microtubule dynamics in lymphocytes using same system (5). Since lymphocyte migration is critical for immune response, our results open a new field to control the immune response via the modulation of migration of lymphocytes. Lastly, collaborating with Dr. Nishimura, Kyusyu University, we found that Rho-ROCK signaling control lysosomal vesicle trafficking via changing the microtubule dynamics (1, 7). The mechanism for intracellular trafficking is now hot field, since it regulated the number of cellular function and one of the best molecular targets for the clinical therapy. Our results shed light to the critical function of cytoskeletal change induced by Rho-ROCK on the vesicle trafficking and pharmacological manipulation of such system for the treatment of several diseases including devastating cancer. Less