川芎嗪刺激骨髓间充质干细胞分泌高表达miRNA-486-5p外泌体促进脑缺血后神经血管再生及机制研究

外泌体替代干细胞治疗是近年来研究的热点。外泌体主要通过运输miRNA调控靶细胞功能，但外泌体内miRNA是选择性包装，并受到细胞外刺激的影响。我们前期研究发现，引经药川芎的有效成分川芎嗪（TMP）预处理骨髓间充质干细胞（BMSCs），分泌高表达miRNA-486-5p的外泌体，促进脑缺血后神经发生和血管生成，但机制尚不清楚。本项目拟在体内和体外，采用药理学、分子生物学和生物信息学等方法，进一步确认TMP预处理的BMSCs外泌体促进脑缺血后神经血管再生；然后明确TMP预处理通过上调BMSCs外泌体miRNA-486-5p表达发挥效应；最后证明miRNA-486-5p通过调控靶基因PTEN及信号通路PI3K/Akt介导TMP预处理的BMSCs外泌体效应。本项目研究不仅揭示了TMP预处理的BMSCs外泌体促进脑缺血后神经血管再生的分子机制，还为干细胞治疗提供一个新策略。

The replacement of stem cells by exosomes is the hot topic in recent years. Exosomes mainly regulates the function of target cells through transferring miRNA, but the exosomal miRNA is selective packaging and is affected by extracellular stimulation. Tetramethylpyrazine (TMP) is a pharmacologically active component from the meridian-guiding herb Rhizoma Chuanxiong. Our previous studies have found that exosomes with high expression of miRNA-486-5p derived from tetramethylpyrazine-stimulated bone marrow mesenchymal stem cells enhance neurovascular regeneration after ischemic stroke, but the mechanism is not clear. In this project, by using methods of pharmacology, molecular biology and bioinformatics in vivo and in vitro, we firstly further confirm that exosomes derived from TMP-preconditioned BMSCs improve neurovascular regeneration after cerebral ischemia. Then we verify that exosomes derived from TMP-preconditioned BMSCs exert its effect through transferring miRNA-486-5p. Finally, we prove that the effect exosomes derived from TMP-preconditioned BMSCs is mediated by miRNA-486-5p direct targeting PTEN and its signal pathway PI3K/Akt. This project not only reveals the molecular mechanism of TMP-preconditioned BMSCs promoting neurovascular regeneration after cerebral ischemia, but also provides a new strategy for stem cells therapy.