Reelin信号通路在MSCs移植治疗新生鼠缺氧缺血性脑损伤中的作用

It is challenging to effectively treat neonates with severe hypoxic-ischemic brain damage (HIBD). Recently mesenchymal stem cells (MSCs) transplantation provides a promising therapy for this disease, and we can improve the efficacy by multiple ways. However, later after transplantation, frequent epilepsy episode often occurs. Reelin signaling pathway is known to play a critical role in neurons' migration and localization, and defects in this pathway will mislead neurons to migrate to be ectopic neurons, consequently disordering the lamellar structure of cerebrum, causing refractory epilepsy. Therefore, we hypothesize that the defective Reelin signaling pathway after MSCs transplantation of rats with HIBD leads to ectopic neurons because of abnormal migration and subsequent formation of abnormal neural network or epileptogenic focus. In this research, we will investigate the Reelin signaling pathway in MSCs transplantation for the neonatal rats with HIBD by a combination of in vitro and in vivo approches including neuropathology, molecular biology, cell biology and electroneurophysiology. This study will help us figure out the determining factors that work on MSCs transplantation for the neonatal rats with HIBD, understand the underlying mechanism of MSCs transplantation therapy, and improve the safty and efficacy of the therapy on HIBD.

重度新生儿缺氧缺血性脑损伤(HIBD)治疗是个难题，对其进行骨髓间充质干细胞(MSCs)移植已成为热点，通过多种途径可促进MSCs植入体内后迁徙及分化，改善神经行为功能，但在移植一定时间后可观察到频繁的癫痫发作。Reelin信号通路是决定新生神经元迁徙及定位的关键因素，研究显示该通路异常可致神经元迁徙异常,引起大脑片层结构紊乱而致顽固性癫痫，因此，我们推测HIBD后进行MSCs移植可能存在Reelin信号通路异常,植入的MSCs迁徙定位异常而产生异位神经元,形成异常神经网络或癫痫灶。本课题拟结合体内、外实验,以Reelin信号通路为切入点,借助神经病理学、分子生物学、细胞生物学及神经电生理技术,研究Reelin信号通路在MSCs移植治疗HIBD中的作用，进一步探明MSCs移植治疗HIBD的影响因素，以提高MSCs移植治疗HIBD的治疗效果及其安全性，为进一步改善HIBD预后提供理论基础。

重度新生儿缺氧缺血性脑损伤(HIBD)治疗是个难题，对其进行骨髓间充质干细胞(MSCs)移植已成为热点，我们前期通过丹参的优化诱导方案可促进MSCs神经性分化及存活效率，但在移植一定时间后可观察到频繁的癫痫发作。而Reelin信号通路是决定新生神经元迁徙及定位的关键因素，研究显示该通路异常可致神经元迁徙异常,引起大脑片层结构紊乱而致顽固性癫痫。本研究通过基因芯片进一步分析了丹参的优化诱导方案诱导MSC神经性分化的机制；通过Western Blotting检测分析了MSC有关Reelin信号通路各蛋白表达特点；通过体内移植试验研究了Reelin信号通路在MSC移植治疗HIBD的调节作用；通过电生理检测研究了移植的MSC神经性分化后的电生理特性。结果提示丹参的优化诱导方案通过逐步改变MSC细胞的多个关键基因而使MSC分化为神经元样细胞；MSC细胞本身不表达Reelin信号通路的各级蛋白，通过体外诱导后，逐渐获得了Reelin信号通路的蛋白；MSC体内移植结果发现体外经丹参诱导获得Reelin完整信号通路后再进行移植，移植的细胞脑内迁移范围更广，但却更显得无序。因此，Reelin信号通路在MS颅内移植替代治疗起着重要的作用，但又不是唯一起作用的信号分子通路。