ROS在缺氧线粒体稳态失衡中的作用和分子机制

Imbalance of mitochondrial homeostasis of pulmonary smooth muscle cells (PASMCs) induced by hapoxia is a key scientific problem of the pulmonary circulation diseases. Our results indicated that the hapoxia-indecued the imbalance of mitochondrial homeostasis is thourou ROS by regulating the expression of mitofusin-1/2, which causes functional and morphylogical abnormity of PASMCs mitichondria. We propose 3 specific aims to test the hypothesis: (1) to examine the sources and species of hypoxia-induced ROS; and the role of ROS in the imbalance of PASMC mitochondrial homeostasis under hypoxic condition, (2) to demonstrate the influence of hypoxia on the expression of mitofusin-1/2, and the role of mitofusin-1/2 in PASMC mitochondrial homeostasis induced by ROS, and (3) to identify signal transduction pathways, protien-protien interaction network involved in the regulation of in mitofusin-1/2 induced by mitochondrial ROS, and the underlying molecular key protiens and molcule mechanisms of the imbalance ofmitichondrial homeostasis induced by ROS. This project will significantly increase our understanding of the role of hypoxia on ROS production and function in PASMCs mitochondria, indentifying the molcule mechanisms of ROS regulating mitofusin-1/2, and is likely to shed insight into a novel mechanisms of hypoxia induced imbalance of mitochondrial homeostasis via ROS regulated mitofusin-1/2.

缺氧导致肺血管平滑肌线粒体稳态失衡是肺循环系统疾病发生、发展的关键环节，机制未明。我们的结果揭示：缺氧通过线粒体ROS 调控线粒体融合蛋白Mfn1/2影响线粒体的融合分裂动态平衡，导致线粒体形态、结构和功能异常。拟通过下述研究证明该假设：1缺氧诱导ROS的来源和种类，ROS在肺动脉平滑肌线粒体稳态失衡中的作用；2 ROS对Mfn1/2的调控,Mfn1/2在mROS 所致的线粒体稳态失衡中的作用；3 mROS 调控Mfn1/2的信号转导系统及蛋白质相互作用网络，明确ROS调控线粒体的分子机制和关键节点蛋白。研究结果将阐明缺氧对ROS的诱导作用及ROS对肺动脉平滑肌细胞Mfn1/2的影响；提出缺氧通过ROS调控线粒体Mfn1/2引起肺血管平滑肌线粒体稳态失衡的新机制。

缺氧可导致肺血管平滑肌线粒体稳态失衡是肺循环系统疾病发生、发展的关键环节，但机制尚不明确。我们的结果揭示：缺氧通过线粒体 ROS 调控线粒体融合蛋白 Mfn1/2 影响线粒体的融合分裂动态平衡，导致线粒体形态、结构和功能异常。拟通过下述研究证明该假设： 1缺氧诱导ROS的来源和种类，ROS在肺动脉平滑肌线粒体稳态失衡中的作用；2 ROS对Mfn1/2 的调控,Mfn1/2 在 mROS 所致的线粒体稳态失衡中的作用；3 mROS 调控 Mfn1/2 的信号转导系统及蛋白质相互作用网络，明确 ROS 调控线粒体的分子机制和关键节点蛋白。从上述实验中我们得出了以下结果：1 ROS调节线粒体动态学变化并介入缺氧引起的肺动脉高压；2融合蛋白Mfn1表达异常主要分布在缺氧肺组织的PASMCs中，并且Mfn1与缺氧诱导的细胞增殖有关；3在肺血管中，ROS能调控缺氧诱导的DRP1的表达；4线粒体来源的活性氧能减轻由缺氧引起的DRP1上调；5体外实验中ROS调控缺氧诱导的DRP1表达；6在细胞内DRP1和ROS / mROS产生一个正反馈调节通路；7数据库以及软件预测 Mfn1/2 作用的蛋白质相互作用网络和关键信号蛋白分子；8缺氧通过 K+通道、HIF-1α、Hsp90 等机制调控线粒体膜电位和有关的线粒体膜蛋白表达；9缺氧通过 HIF-1α信号转导途径，调控线粒体膜电位和线粒体膜蛋白，保护细胞凋亡；10缺氧通过 Hsp90 信号转导途径，调控线粒体膜电位，进而调控线粒体膜蛋白表达；11缺氧通过过氧化物酶增殖酶增殖物受体γ共激活体活因子1α（PGC-1α）诱导线粒体生物合成。上述研究结果将阐明缺氧对 ROS 的诱导作用及 ROS 对肺动脉平滑肌细胞 Mfn1/2 的影响；提出缺氧通过 ROS 调控线粒体 Mfn1/2 引起肺血管平滑肌线粒体稳态失衡的新机制。