NOX1介导的活性氧调控Rac1/Cdc42-ERK1/2通路在血小板前体微管重排中的作用及机制研究

巨核细胞经细胞骨架重排形成血小板前体(PPF)是血小板生成的关键环节，Rac1/Cdc42介导了PPF微管tubulin的重排。活性氧(ROS)在促进PPF形成过程中发挥着枢纽作用，但具体调控机制不明。我们研究发现，NOX1过表达后ROS生成增加不仅可引起Rac1/Cdc42活性增强而激活ERK1/2通路，而且会促进微管向细胞一极聚集，提示ROS具有激活Rho GTP酶而调控微管重排的作用。因此，我们推测NOX1介导的ROS可能通过调控Rac1/Cdc42-ERK1/2通路而促进微管重排，从而促进PPF形成。本项目拟以人CD34+细胞诱导分化形成的巨核细胞和巨核细胞株Meg-01为研究对象，采用RNA干扰和激光共聚焦等分析技术，分析NOX1介导的ROS调控Rac1/Cdc42活性及其引起微管重排的分子机制，探讨ROS在PPF形成中的具体作用，从而为血小板生成终末阶段的调控研究提供新思路。

The cytoskeleton rearrangement of megakaryocyte for proplatelet(PPF) is the key step of platelet production, while Rac1/Cdc42 mediates tubulin cytoskeleton reorganization of PPF. As known, PPF formation is orchestrated by reactive oxygen species(ROS), however, the regulation mechanism has not been fully uncovered. Our early study showed that ROS accumulation caused by NOX1 over-expression could not only stimulate Rac1/Cdc42 activity and then result in ERK1/2 phosphorylation, but also lead to the reorganization tubulin cytoskeleton to one cell polar, which indiates that ROS may regulate the reorganization of tubulin cytoskeleton via Rho GTPase activation. Therefore, we postulate that ROS from NOX1 is likely to promote tubulin cytoskeleton reorganization to facilitate PPF formation through the regulation of Rac1/Cdc42-ERK1/2 signaling. In this study, by using RNA interference and laser confocal, etc, we intend to investigate the molecular mechanism of Rac1/Cdc42 activity and subsequent tubulin cytoskeleton reorganization regulated by ROS from NOX1, which aims to explore the exact role of ROS on PPF formation, and then to provide new insights into the study of terminal stages of thrombopoiesis.