诱导神经干细胞移植调控创伤性脑损伤后炎症反应的作用和机制

Induced neural stem cells (iNSCs) directly reprogrammed from autologous somatic cells are more suitable for regenerative medicine because they have similar capacity self-renewal and differentiation as NSCs and are more convenient than NSCs. Recently, we reported that grafted NSCs can decrease the infiltration of immune cells, whereas up-regulate the expression of IL-10 so as to modulate the inflammation after TBI. Besides, we found that NSCs can secrete sTNFRI and sTNFRII which are antagonisms of TNF-α to regulate the polarization and function of macrophages. We have confirmed that iNSCs can directly migrate into cerebral infarction to restore nerve function, and iNSCs similar to NSCs can secrete neurotrophic factors to protect neuron. We performed Agilent mRNA expression profile chips, RT-QPCR and ELISA and found that iNSCs as well as NSCs can express immunomodulation related factors. In order to further explore iNSC immune regulation characteristic, we plan to observe the effects of grafted iNSCs on the inflammation post-TBI and the interactions between iNSCs and a variety of immune cells via co-culture experiment. Meanwhile, we will transplant the co-culture trained iNSCs to observe their effects on the inflammation post-TBI when compared with NSCs. We hope this study can elucidate iNSC immune regulation function and mechanism of inflammation after TBI.

诱导神经干细胞(iNSCs)直接由自体体细胞重编程而来，不仅具有神经干细胞(NSCs)自我更新和多向分化特性，而且较NSCs应用更方便。我们前期研究已明确iNSCs可促进神经功能重塑。INSCs与NSCs作用相似，均可分泌神经营养因子，然而iNSCs是否具有免疫调控特性有待研究。我们已完成了Agilent mRNA表达谱芯片、RT-QPCR和ELISA实验，结果发现iNSCs可表达免疫调控相关因子。为进一步探讨iNSCs免疫调控特性，本课题拟：首先将iNSCs、NSCs移植到创伤性脑损伤(TBI)小鼠脑内，观察二者调控TBI后炎症反应的异同；再将iNSCs、NSCs分别与多种免疫细胞共培养，观察细胞间相互作用；最后将与免疫细胞离体共培养的iNSCs、NSCs移植到TBI小鼠脑内，观察宿主和移植物的相互作用。期望通过本研究阐明iNSCs移植调控TBI后炎症反应的作用和机制。

创伤性脑损伤（TBI）无论是在平时或战时均是神经外科常见病，由于TBI患者病情复杂多变，尚缺乏有效精准的治疗方案，因而一直以来都是国防建设的重点研究课题，本项目以诱导型神经干细胞/神经干细胞（iNSCs/NSCs）移植治疗TBI为立足点，探讨iNSCs/NSCs调控TBI后炎症反应的作用和机制，以深化对iNSCs/NSCs免疫调控特性的认识，指导iNSCs/NSCs移植治疗TBI后炎症反应介导的继发性脑损伤。通过为期四年的研究，主要研究结论如下：.1、INSCs和NSCs移植可有效抑制TBI后炎症细胞浸润，降低炎症因子水平和NF-κB信号通路活化水平，发挥调控TBI后炎症反应的作用，此外iNSCs和NSCs在调控TBI后炎症反应中作用相似。.2、INSCs/NSCs可通过CXCL12/CXCR4信号通路调控小胶质细胞/巨噬细胞的极性/活化状态。此外，iNSCs/NSCs可调控T细胞活化状态。.3、INSCs/NSCs经与小胶质细胞/巨噬细胞（M1型）或活化T细胞共培养可提高其在TBI动物脑内存活率，从而有助于iNSCs/NSCs发挥调控TBI后炎症反应保护神经的作用。.4、经静脉移植iNSCs/NSCs能表达补体调节分子Crry抑制TBI后补体活化，减轻继发性脑损伤。.5、INSCs/NSCs及其分化产物星形胶质细胞可通过表达补体调节分子Crry抑制TBI后补体活化，发挥保护神经细胞，减轻继发性脑损伤的作用。.综上，本项目阐明了iNSCs移植调控TBI后炎症反应的作用和机制，为iNSCs临床免疫调控与神经修复治疗TBI打下坚实基础，具有广阔的国防应用前景。