基于Netrin-1/UNC5B促进骨髓间充质干细胞移植治疗大鼠缺血性脑卒中的研究

Bone mesenchymal stem cells (BMSCs) has been restricted in the clinical application of cerebral ischemia therapy, due to its low survival and migration rates of transplanted cells in vivo. Our preliminary study has found that the survival and migration rates of BMSCs could be significantly improved by Netrin-1 (NT-1), one of the axon-guidance factors. NT-1 promoted the recovery of middle cerebral artery occlusion(MCAO) model in rats. Furthermore, UNC5B, a receptor of NT-1, was highly expressed in BMSCs.Since related research on the underlying mechanism of the interactions between NT-1 and BMSCs has been lacking, we proposed to address this problem by investigating the NT-1/UNC5B signaling pathway. We hypothesized that the NT-1/UNC5B pathway might mediate the migration and survival rates of BMSCs, and hence enhance the effects of BMSCs to cerebral ischemia. Basing on the preliminary result, current tool medicine and biological protocols, we therefore will establish model of MCAO and study the effects of NT-1/UNC5B signaling pathway on BMSCs therapy after cerebral ischemia in rats. Our main goal is to clarify the cell and molecular mechanisms of NT-1/UNC5B signaling pathway in promoting migration and survival of BMSCs, and provide new ideas for the post-stroke rehabilitation and functional reconstruction.

骨髓间充质干细胞（Bone Mesenchymal Stem Cells，BMSCs）移植治疗缺血性脑卒中因其存在迁移率低、存活率低等问题严重制约了临床应用的发展。申请者前期研究已发现神经导向因子Netrin-1（NT-1）能够促进BMSCs存活和迁移，改善BMSCs移植治疗大鼠MCAO神经损伤的效果；同时，发现BMSCs上主要表达NT-1受体亚型UNC5B。由于目前国内外尚缺乏NT-1对BMSCs的作用及其机制研究，申请者提出：NT-1/UNC5B可能介导了BMSCs的迁移、存活及对缺血性脑卒中的治疗作用。本项目拟在现有研究结果的基础上，制备大鼠MCAO模型，应用工具药和相关分子生物学技术，研究、明确NT-1/UNC5B在BMSCs移植治疗缺血性脑卒中的作用，进一步阐明NT-1/UNC5B促进BMSCs迁移、存活的细胞和分子机制，为缺血性脑卒中后的组织修复和功能重建提供新的思路。

骨髓间充质干细胞（Bone Mesenchymal Stem Cells，BMSCs）移植治疗缺血性脑卒中因其存在迁移率低、存活率低等问题严重制约了临床应用的发展。申请者前期研究已发现神经导向因子Netrin-1（NT-1）能够促进BMSCs存活和迁移，改善BMSCs移植治疗大鼠MCAO神经损伤的效果；同时，发现BMSCs上主要表达NT-1受体亚型UNC5B。由于目前国内外尚缺乏NT-1对BMSCs的作用及其机制研究。本项目在原有研究结果的基础上，制备大鼠MCAO模型，应用工具药和相关分子生物学技术，研究、明确NT-1/UNC5B在BMSCs移植治疗缺血性脑卒中的作用，进一步阐明NT-1/UNC5B促进BMSCs迁移、存活的细胞和分子机制。研究结果发现：UNC5B介导了离体环境下Netrin-1对BMSCs定向迁移、存活的促进作用，并且这一作用很可能是通过AKT通路产生影响；BMSCs移植治疗大鼠MCAO模型，沉默UNC5B后大鼠脑梗死体积更大、神经功能缺损症状更重。这一研究结论，从改善干细胞迁移率、存活率两方面为脑血管病的干细胞移植治疗提供新的思路：即Netrin-1/UNC5B有望成为干细胞移植治疗缺血性脑血管病的新干预靶点。