氧化应激保护机制在间充质干细胞治疗急性肺损伤中的作用研究

Acute lung injury (ALI) caused by direct or indirect wounding agents can easily progress to acute respiratory distress (ARDS), or directly leads to significant mortality. Despite more and more clinical attention, ALI is now still lack of fully effective treatments. With the deepening of study on mesenchymal stem cell (MSC), certain prospect of clinical application of MSC treatment for ALI has emerged. However, local state of oxidative stress (OS) in the lung traumatic microenvironment largely restricts the repairing ability of exogenous MSC. Therefore, based on our previous exploration of MSC in wound repair and healing, in this project we tend to take γ-GCL (a mitochondrial GSH synthesis rate-limiting enzyme) of MSC, as target to enhance MSC’s anti-apoptosis ability under OS by means of genetic modification. Later, whether MSC could conduct anti-OS modification and subsequently function in the repair process can be real-time observed with application of established ALI models in vitro and in vivo, respectively, which thus creates an opportunity to clarify the mechanism of protection against oxidative stress in the MSC treatment of ALI from the cellular dimension to the tissue level, and so as to find out a feasible solution to eliminate the obstacles in the micro environment of inflammation. Ultimately, this project can provide innovative strategies for effectively treating lung injury and post traumatic inflammatory diseases by using MSC.

由各种直接和间接致伤因素所致的急性肺损伤(ALI)，极易进展至严重阶段的急性呼吸窘迫综合征(ARDS)，甚至导致患者死亡，尽管在临床上日益受到重视，但目前尚缺乏有效治疗手段。随着间充质干细胞（MSC）研究不断深入，其用于治疗ALI和ARDS具有一定的临床应用前景。然而，肺部创伤微环境中高氧化应激状态很大程度上严重制约着外源性MSC修复功能。因此，本项目在我们前期对MSC参与创伤修复及促愈合的探索基础上，拟首先以线粒体GSH合成限速酶γ-GCL为靶点，采用基因修饰的方法增强MSC在氧化应激环境中抗凋亡能力。然后，通过建立的体外和体内急性肺损伤模型，进一步动态实时观察MSC是否能进行抗氧化应激修饰进而对损伤肺组织发挥修复作用，尝试从细胞维度到组织层面阐明氧化应激保护在MSC治疗急性肺损伤的机制，从而找到消除炎症微环境阻碍因素的可行途径，将为利用MSC有效治疗肺损伤以及创伤后炎症性疾病提供创新。

由各种直接和间接致伤因素所致的急性肺损伤(ALI)，极易进展至严重阶段的急性呼吸窘迫综合征(ARDS)，甚至导致患者死亡，尽管在临床上日益受到重视，但目前尚缺乏有效治疗手段。随着间充质干细胞（MSC）研究不断深入，其用于治疗ALI和ARDS具有一定的临床应用前景。活性氧簇为ALI中重要的致细胞死亡的因素。如何对抗ROS的损伤作用在ALI治疗中有重要的意义。本课题组使用还原型谷胱甘肽预处理MSC细胞，使其具有对抗ROS的功能。实验结论表明MSC在预处理后其对抗ROS的能力增强，检测P53、凋亡指标均较对照组减少,体内实验也证实了该假设。同时，本课题组在非小细胞肺癌研究中发现高迁移率族蛋白B1（high mobilitygroupbox 1,HMGB1）在肺癌组织中存在高表达情况，能促进细胞增殖、活化并降低其对顺铂的敏感性，考虑其为细胞生存的主要靶点。巨噬细胞迁移抑制因子（MIF）同为肺癌的重要增殖靶点，考虑其激动剂可作为ALI治疗中的主要位点，为ALI提供重要的治疗方向。