β-arrestin2依赖的κ阿片受体内化调控少突胶质细胞分化和髓鞘形成的实验研究

Identification of novel pathways and molecules that can promote OPC differentiation represents a promising approach for demyelination disease. Previously, we have built up a high-throughput screening system that allows examining the effects of compounds in promoting OPC differentiation and myelination. Upon a completion of screening a 250 compound GPCR library, we identified a cluster of Kappa opioid receptor agonists, which are highly potent in promoting myelination. Further we found that KOR is a positive regulator for OPC differentiation by using a KOR conditional knockout line, but the mechanisms underlying this process are still unclear. Our preliminary data indicated that β-arrestin2 mediated KOR internalization may be an essential step for KOR activation. Thus we propose to investigate the role of β-arrestin2 in promoting OPC differentiation and myelination by using β-arrestin2 and KOR double knockout mice. To understand the downstream of KOR signaling, we will build a library that contains the compounds targeting individual potential molecule of KOR, and evaluate the effects of these compounds by using the BIMA system. The completion of the project will provide novel targets and compounds for remyelination therapeutics.

发现能促进少突胶质前体细胞（OPC）分化和髓鞘形成的关键途径，对脱髓鞘疾病的治疗有重要意义。申请人前期建立了纳米微柱阵列（BIMA），用于高通量筛选促髓鞘再生药物。通过筛选靶向G蛋白偶联受体化合物库，首次鉴定了一组κ阿片受体（KOR）激动剂，能够高效促进OPCs分化和髓鞘形成。采用KOR条件敲基因小鼠证明KOR是正向调控OPC分化的重要受体，但机制不清。预实验结果提示：β-arrestin2介导的KOR内化可能是其促进OPC分化和髓鞘形成的重要途径。本课题拟采用条件性KOR及β-arrestin2敲除小鼠，首先明确β-arrestin2介导了KOR内化；并证明KOR的内化是KOR激动剂促进OPCs分化和髓鞘再生的关键环节；最后针对KOR下游可能的信号通路，建立小分子化合物库，利用BIMA筛选，鉴定KOR下游关键靶分子。本项目的完成将有望阐明KOR的分子机制并为促髓鞘再生治疗研究提供新靶点。

发现能促进少突胶质前体细胞（OPC）分化和髓鞘形成的关键途径，对脱髓鞘疾病的治疗 有重要意义。申请人前期建立了纳米微柱阵列（BIMA），用于高通量筛选促髓鞘再生药物。通过筛选靶向G蛋白偶联受体化合物库，首次鉴定了一组κ阿片受体（KOR）激动剂，能够高效促进OPCs分化和髓鞘形成。采用KOR条件敲基因小鼠证明KOR是正向调控OPC分化的重要受体。本课题采用KOR条件敲基因小鼠和KOR特异性激动剂，结合免疫组织化学、行为学、电生理等方法，阐明了KOR在调节髓鞘形成和少突胶质细胞分化中的作用，发现了髓鞘对突触形成的重要调节作用。取得了以下重要研究结果：1、发现kappa阿片受体激动剂促进髓鞘形成改善脑白质损伤的作用和机制，该部分研究结果发表在Neuron, 2018, 22, 99(4): 689-701（第一标注）；2、发现了kappa阿片受体调节成体髓鞘形成的作用和机制，该部分研究结构发表在Nature Neuroscience. 2020, 23(4):481-486 (IF 21.126，第二标注)；3、受邀撰写了专著：Chapter11: Kappa Opioid Receptor and Oligodendrocyte Remyelination， Book: Vitamins and Hormones (Edited by Gerald Litwack), vol 111，281-297. (第一标注)。本项目首次揭示了髓鞘发育对神经功能的调节作用机制，研究论文被F1000推荐和评价，并当期论文评述。本项目的完成为理解KOR的分子机制，和以促髓鞘再生为治疗靶点研究提供理论基础。在本课题的资助下，获批教育部青年长江学者1名，培养毕业硕士研究生2名，培养了髓鞘学研究团队。