高表达miR132-3p间充质干细胞exosomes通过刺激神经血管再生改善脑缺血损伤的研究

After ischemic stroke, ischemia and hypoxia led to the damaged brain tissue. Improving angiogenesis, blood supply, microcirculation and tissue microenvironment in the repaired tissue should be the common therapeutic targets for cerebral ischemia damge. Evidence has showed that angiogenesis and tissue repair could be promoted by mesenchymal stem cells (MSCs), However, the efficacy of MSCs could be decreased in pathological conditions. Exosomes (EXs) derived from MSCs could go through the blood brain barrier (BBB) and play function role in various cells and microenvironment in the brain tissue, can exert the same effect as MSCs, or may be even better. MiRNAs could be carried and transported by MSC-EXs to their recipient cells, MiR132-3p is an important functional gene which could regulate various target genes participating in the process of angiogenesis. Our results showed that miR132-3p overexpressing enhanced the protective effect of MSC-EXs in the damaged VECs induced by ischemia/hypoxia, which indicated that it is possible to improve the therapeutic effects of MSCs through miR132-3p overexpression. Thus, in the present project, we will comprehensively investigate whether miR132-3p overexpression MSC-EXs can greatly accelerate their recipient cell funtions, detect the contribution of miR132-3p overexpression MSC-EXs to the regulation of neurogenesis, angiogenesis and microenvironment in impaired brain tissue in animal models, and the therapeutic effect of miR132-3p overexpression MSC-EXs and the underlying mechanism will also be explored. Therefore, this proposal has important theoretical and clinical significance.

缺血性脑卒中发生后，脑组织因缺血缺氧受损。加强新生血管生成及神经再生，改善缺血病灶血供和微环境是治疗的有效靶点。间充质干细胞（MSCs）能促进血管新生和改善微环境加速组织修复。然而在病理转态下，其作用受影响。间充质干细胞释放的外泌体（MSC-EXs）能通过血脑屏障作用于脑组织中多种细胞、影响微环境，也能发挥上述作用，并且效果可能更好。MSC-EXs能携带并传递miRNAs至靶细胞，其中MiR132-3p能调节多种血管损伤修复相关基因。我们前期研究发现，miR132-3p高表达能加强MSC-EXs对缺血缺氧受损VECs的保护，提示miR132-3p过表达可能提高MSC-EXs作用及疗效。本项目将全面研究miR132-3p高表达MSC-EXs对受体细胞功能的影响，并在动物模型上研究其对缺血脑组织神经血管再生及微环境的调节作用，探讨其对脑缺血损伤的治疗效果及机制。因此，具有重要意义和应用价值。

缺血性脑卒中（IS）发生后，脑组织因缺血缺氧受损。加强新生血管生成及神经再生，改善缺血病灶血供和微环境是治疗的有效靶点。间充质干细胞（MSCs）能促进血管新生和改善微环境加速组织修复。然而在病理状态下，其作用受影响。间充质干细胞释放的外泌体（MSC-EXs）能通过传递其携带的miRs调节脑组织中多种细胞功能，也能发挥上述作用，并且效果可能更好。MiR-132-3p能调节多种血管损伤修复相关基因。我们前期研究发现，miR-132-3p能加强MSC-EXs对血管内皮细胞（ECs）的保护。因此，本项目首先研究富含miR-132-3p的MSC-EXs对受体细胞ECs和神经元功能的调控，并深入探讨调控机制；其次，研究输注富含miR-132-3p的MSC-EXs对IS小鼠脑缺血损伤的保护。. 我们研究发现，富含miR-132-3p的MSC-EXs能通过靶向调控下游基因RASA1，激活Ras/PI3K/Akt/eNOS信号通路发挥对缺氧/复氧损伤ECs和神经元多种细胞功能的保护作用。在IS模型小鼠中，富含miR-132-3p的MSC-EXs能通过抑制脑血管内皮细胞ROS生成和凋亡，改善IS小鼠脑缺血损伤。本研究能够阐明MSC-EXs及其携带的功能基因miR-132-3p在神经血管功能保护及IS治疗中的作用及机制，为神经血管功能调控提供新的靶标，为IS治疗提供新策略及理论依据。. 本项目共发表相关论文6篇。项目的研究成果对基础及临床研究均具有较高的指导意义，为神经血管功能调控及缺血性脑卒中治疗研究提供新的靶标及新方法，可开发或筛选新的缺血性脑卒中治疗药物，成果的进一步应用将帮助改善缺血性脑卒中患者生活质量，减轻疾病为患者和社会带来的沉重负担，产生良好的社会和经济效益。