慢性正己烷中毒是我国严重职业病，可诱发轴索变性为特征的中枢-周围神经病。然而，尚无有效干预手段恢复其严重受损神经功能。干细胞外泌体能模拟干细胞生物学功能，对轴突损伤有修复作用。根据文献分析和前期研究，申请者提出干细胞外泌体介导NGF促进正己烷中毒大鼠轴突再生修复机制假设，为本课题立项奠定理论基础。本研究构建正己烷中毒和间充质干细胞外泌体干预大鼠模型及原代神经元模型；用神经损伤检测平台、电生理技术和形态学观察，评价神经功能恢复和轴突修复程度；用免疫荧光技术检测Texas-red标记间充质干细胞外泌体在受损神经组织靶向分布；用RNA沉默技术、荧光素酶报告基因技术等，探讨干细胞外泌体介导NGF依赖性激活PI3K/Akt通路及下游信号，促进正己烷中毒大鼠轴突再生修复作用及机制。本研究将为慢性正己烷中毒神经组织损伤修复，提供干细胞外泌体干预新方法，也为其它化学物暴露所致神经组织损伤修复提供参考依据。

Chronic n-hexane poisoning is a serious occupational disease in China, it could induce central-peripheral neuropathy which is characterized by axonal degeneration. However, there is no effective treatment to restore its severely impaired nerve function. Stem cell-derived exosomes have the similar biological function with stem cells and could recover the axon injury. According to the literatures and previous studies, the applicant put forward the hypothesis that stem cell-derived exosomes could promote the regeneration of axon in rats with n-hexane exposure, laying the theoretical foundation for this study. In this study, we established the model of mesenchymal stem cell-derived exosomes treatment to the exposure to n-hexane in rats and primary neuron in vitro. The nerve damage detecting platform, electrophysiological technique and morphological observation were used to evaluate the recovery of nerve function and the degree of axon repair. Moreover, immunofluorescence technique was used to detect the targeted distribution of Texas-red-labeled mesenchymal stem cells exosomes in the damaged nerve tissue. Besides, the gene technique and luciferase reporter gene technique were also used to explore the mechanism that the exosomes by NGF-dependent PI3K/Akt pathway and downstream signaling promotes the axonal regeneration in n-hexane poisoning rats. This study will provide a new method for the treatment of nerve tissue damage caused by chronic exposure to n-hexane, and also provide reference for the repair of nerve tissue injury caused by exposure to other chemicals.