抑制LINGO-1促进移植人少突胶质前体细胞分化和髓鞘化的实验研究

White matter injury (WMI), for which no effective therapy has been foud yet, is one of the main causes for children with cerebral palsy or mental retardation. Oligodendrocyte progenitor cells (OPCs) are the precursor cells of myelin-forming cells in the central nervous system, and OPCs transplantation brings hope for WMI. However, the poor differentiation and myelination of transplanted human OPCs in WMI rats inhibit the application of OPCs. We found the expression of LINGO-1 increasing in the injured area of WMI rats. In addition, several studies showed that LINGO-1 played crucial and inhibitory role in differentiation and myelination of OPCs of animal origin. Therefore we speculate that the upregulation of LINGO-1 may be the key factor that inhibit the transplanted OPCs differentiation and myelination. The applicant takes the lead in gaining human OPCs from neural stem cells, and will carry out a new research to down-regulate the mRNA expression of LINGO-1 by siRNA or block the LINGO-1 fuction by special antibody respectively, and then observe the OPCs differentiation and myelination in vitro and in WMI rats, analyze the function of LINGO-1 in the differentiation and myelination of transplanted OPCs and further research associated signaling pathways. This study will provide new ideas and technical support for drug development or the treatment of newborn with WMI by OPCs transplantation.

新生儿脑白质损伤（white matter injury，WMI）是儿童脑瘫和智障的主要原因之一，无特效疗法。少突胶质前体细胞(oligodendrocyte progenitor cells,OPCs)是中枢神经系统的成髓鞘细胞，有望治疗此疾病。但将人OPCs移植到脑白质损伤模型大鼠脑后分化髓鞘化困难，我们在新生鼠脑白质损伤模型中发现LINGO-1高表达，现已证明LINGO-1是抑制动物OPCs分化和髓鞘化的关键因素，推测其可能与此有关。申请者在国内率先获得人神经干细胞诱导的OPCs，拟分别通过RNAi降低LINGO-1表达及拮抗其蛋白功能后，观察人OPCs在体外和移植到WMI大鼠模型后的分化和髓鞘形成情况，分析LINGO-1功能，并进一步研究相关的信号通路。探索LINGO-1在人OPCs分化、髓鞘化中的功能及调控机制将为未来OPCs移植治疗新生儿WMI提供理论依据与技术支持。

早产儿脑白质损伤（white matter injury，WMI）是儿童脑瘫和智障的主要原因之一，但目前无特效疗法。少突胶质前体细胞(oligodendrocyte progenitor cells, OPC)是中枢神经系统的唯一的天然成髓鞘细胞，是治疗WMI理想的种子细胞，但将人 OPC 移植到脑白质损伤模型大鼠脑后分化髓鞘化困难，研究发现lingo-1可能是抑制OPC分化成髓鞘的因素之一。本项目中，我们发现lingo-1和WMI的髓鞘损伤关系密切，在模型后lingo-1基因和蛋白表达上升，7天到达峰值并维持至14天，随后下降。我们建立RNA干扰lingo-1的慢病毒干扰载体，将人OPC中lingo-1的表达降低70%。随后我们对比WMI后不同时间和不同移植路径后移植OPC成髓鞘效果，建立了适合研究OPC体内成髓鞘功能的WMI细胞移植模型。将低表达Lingo-1的OPC移植到WMI模型动物脑内，发现 Lingo-1低表达的OPC成髓鞘能力更强，机制分析发现lingo-1低表达后促进OPC成髓鞘这一过程跟OPC中ERK信号的磷酸化有关。在研究中，我们也发现了咪康唑药物对OPC存在內源保护作用，并能促进移植人OPC成髓鞘。本项目初步证实抑制lingo-1表达可以促进移植人OPC体内分化成髓鞘，为促进人OPC体内成髓鞘提供了新的研究靶点，有助于WMI以及其他脱髓鞘疾病的治疗策略开发。