微电流场诱导的干细胞外泌体lncRNA-MALAT1调控脊髓神经细胞自噬及其机制研究

干细胞外泌体及其携带的lncRNA为脊髓损伤的修复提供了新的小分子治疗手段。利用我们前期构建的微电流场细胞培养体系，发现经微电流场刺激后的人脐带间充质干细胞外泌体中lncRNA-MALAT1表达显著升高，并对脊髓损伤后神经细胞自噬具有保护作用，但lncRNA-MALAT1对下游分子、信号通路、神经功能保护等尚有许多重要问题有待研究。本项目拟在前期研究基础上：①筛选并验证MALAT1与下游miRNAs在脊髓损伤后的表达及靶向关系；②在细胞、组织水平检测自噬相关信号通路中作用靶点的变化，如PI3K、Akt、mTOR、Wnt、β-连环蛋白、GSK-3β、MKKK、MKK、MAPK等；③经MALAT1干预后，在动物水平观察神经细胞及功能的保护效果。本研究结果将阐明外泌体MALAT1对神经细胞产生保护作用的下游靶向分子、细胞机制及具体调控的信号通路，为脊髓损伤修提供新的非细胞治疗策略。

The exosomes of stem cells and the lncRNA carried by stem cells provide a new small molecular therapy for repair of spinal cord injury, and the microcurrent field cell culture system constructed in our early stage was used. It was found that the expression of lncRNA-MALAT1 in the exosomes of human umbilical cord mesenchymal stem cells stimulated by microcurrent field was significantly increased, and had a certain protective effect on autophagy of nerve cells after spinal cord injury. However, there are still many important issues to be studied, such as the effect of lncRNA-MALAT1 on downstream molecules, signaling pathways, cellular mechanism, neural function protection and so on. On the basis of previous studies, (1) this project intends to screen and verify the expression and targeting relationship between MALAT1 and downstream miRNAs after spinal cord injury, (2) to detect the changes of targets in autophagy-related signaling pathways at the cellular and tissue levels, Such as PI3K, Akt, mTOR, Wnt, β-catenin, GSK-3 β, MKKK, MKK, MAPK, etc. (3) After MALAT1 intervention, the protective effects of nerve cells and their functions were observed at the animal level. The results of this study will elucidate the specific downstream targeting molecules, cellular mechanisms and specific regulatory signaling pathways of exosome lncRNA MALAT1 on nerve cells, and provide a new acellular treatment strategy for spinal cord injury repair.