从线粒体动力学角度研究氢气治疗重度脓毒症的具体机制

Severe sepsis is the leading cause of death in critically ill patients with no effective therapeutic method available. My published results prove that 2% hydrogen gas can effectively improve the survival and organ function in mice with severe sepsis, which is closely correlated with activation of Nrf2/HO-1 pathway. However, the detailed mechanisms are still unclear. The balance of mitochondrial dynamics (fusion/fission) is critical to the morphology and function of mitochondria, and its impaired balance plays an important role in development of sepsis, which is also correlated with Nrf2/HO-1 pathway. Therefore, we hypothesized that hydrogen gas can protect against severe sepsis through Nrf2/HO-1 pathway activation-induced balance of mitochondrial dynamics. In this study, using wild-type and Nrf2 knockout mice, we will firstly investigate that hydrogen gas can regulate mitochondrial dynamics balance in the treatment of severe sepsis through measurement of the mitochondrial fusion/fission, mitophagy and biogenesis, as well as mitochondrial morphology and function in mice (severe sepsis) and in vascular endothelial cells (a cell culture model of sepsis). Furthermore, we will investigate the roles of Nrf2/HO-1 pathway in this process. In conclusion, we will prove that hydrogen gas can protect against severe sepsis through Nrf2/HO-1 pathway activation-induced balance of mitochondrial dynamics, which provides a theoretical basis for hydrogen treatment in sepsis and lays a foundation for its clinical application.

重度脓毒症是危重病患者的主要死因，尚无有效治疗方法。申请人已发表的结果证实2%氢气有效改善重度脓毒症小鼠的存活率和器官功能，与激活Nrf2/HO-1通路密切相关，但具体机制仍不清。线粒体动力学（融合/分裂）平衡是维持线粒体形态和功能的关键因素，其平衡紊乱是脓毒症发病机制的重要环节，与Nrf2/HO-1有关。因此，本课题假设：氢气通过激活Nrf2/HO-1通路调控线粒体动力学平衡发挥对重度脓毒症的保护作用。本项目拟利用野生型和Nrf2基因敲除型小鼠，采用血管内皮细胞模型和重度脓毒症动物模型，通过检测线粒体融合/分裂、自噬和生物合成的相关分子表达，线粒体形态和功能，从线粒体动力学角度阐明氢气治疗脓毒症的具体机制，进一步探讨Nrf2/HO-1在此过程中的作用，明确氢气通过激活Nrf2/HO-1通路调控线粒体动力学平衡发挥对重度脓毒症的保护作用，为氢气治疗脓毒症提供理论依据，为其临床应用奠定基础。

重度脓毒症是危重病患者的主要死因，尚无有效治疗方法。本课题前期研究发现2%氢气有效改善重度脓毒症小鼠的存活率和器官功能，但氢气未能提高Nrf2基因敲除型脓毒症小鼠的存活率，也未降低其血清氧化应激和炎症水平，提示Nrf2/HO-1通路激活可能在氢气治疗脓毒症中起关键作用，但具体机制仍不清。线粒体动力学（融合/分裂）平衡是维持线粒体形态和功能的关键因素，其平衡紊乱是脓毒症发病机制的重要环节，与Nrf2/HO-1有关。本课题在前期研究的基础上，采用PCR、Western-blot、ELISA、IHC、EMSA等分子生物学方法，利用野生型和Nrf2基因敲除型小鼠，通过血管内皮细胞模型和重度脓毒症动物模型，检测线粒体形态和功能，线粒体融合/分裂、生物合成和自噬相关蛋白，证明氢气通过调控线粒体动力学治疗脓毒症；另外通过检测Nrf2基因转录、蛋白表达和核转位活性及下游靶基因的表达，并利用相关干预剂，观察对线粒体动力学相关蛋白表达的变化以及氢气保护脓毒症效应的影响，明确了氢气通过激活Nrf2/HO-1通路调控线粒体动力学平衡发挥对重度脓毒症的保护作用。为氢气治疗脓毒症提供理论依据，为其临床应用奠定基础。