Bcl-2过表达及其亚细胞定位对BMSCs移植治疗大鼠脊髓损伤的影响及其机制研究

骨髓基质干细胞(BMSCs)移植治疗脊髓损伤(SCI)能促进神经功能恢复。但BMSCs能否直接促进轴突再生和髓鞘形成尚未明确，且还存在着移植后存活率和向神经细胞分化率较低的问题。Bcl-2能促进细胞存活和神经分化，并可通过亚细胞定位促进轴突再生。前期研究发现BMSCs的功能发挥与Bcl-2上调密切相关。课题组假设：过表达Bcl-2能促进BMSCs在SCI移植体内存活和向神经细胞分化，并能通过亚细胞定位激活Ca2+-ERK/CREB通路促进轴突再生。本课题拟构建过表达不同亚细胞定位的Bcl-2的BMSCs，移植治疗SCI。利用免疫荧光染色、免疫印迹、神经示踪和行为学等技术检测移植体内BMSCs的存活、分化、轴突再生、髓鞘形成和功能恢复，以及Ca2+-ERK/CREB通路的活化情况；以验证Bcl-2过表达和亚细胞定位对BMSCs移植治疗SCI的影响及其机制，为临床治疗SCI提供新的依据和方向。

Bone marrow stromal stem cells (BMSCs) transplantation for spinal cord injury (SCI) has been shown to improve functional recovery. However, whether BMSCs can directly promote axonal regeneration and myelination is still unclear, and the therapy is limited by the low survival rate and low neural differentiation rate of BMSCs after transplantation. Bcl-2 can promote cell survival and neural differentiation, and support axonal regeneration through its specific subcellular localization. Our previous studies have found that up-regulation of Bcl-2 is closely related to the efficacy of BMSCs. We hypothesize that overexpression of Bcl-2 can promote the survival and neural differentiation of BMSCs after transplantation for SCI, and activate Ca2+-ERK/CREB pathway through its specific subcellular localization to support axonal regeneration. In this project, BMSCs overexpressing Bcl-2 with different subcellular localization will be constructed and transplanted for SCI. Immunofluorescence staining, Western blot, neural tracing and behavior tests will be used to detect the survival and neural differentiation of BMSCs, axonal regeneration, myelination, functional recovery and the activation of the Ca2+-ERK/CREB pathway in the injured spinal cord after BMSCs transplantation, in order to verify the effects of Bcl-2 overexpression and subcellular localization on BMSCs transplantation for SCI and their underlying mechanisms, and to provide new theoretical basis and technical support for clinical treatment of SCI.