从JAK/STAT信号通路探讨CIG抗多发性硬化炎性脱髓鞘的分子机制

Inflammatory demyelination is a hallmark of multiple sclerosis (MS). We found in our previous study that CIG had effect on inflammatory demyelination in Lewis rats, and further prevented the development of experimental autoimmune encephalomyelitis (EAE). However, the molecular mechanism underlying this effect has not been elucidated. It is well known that MS development mainly mediates by Th1 and Th17 T lymphocyte and the JAK/STAT pathway is the major signaling pathway regulating Th1 and Th17 differentiation and their functions. Therefore, in the present study we will investigate the molecular mechanism underlying anti-inflammatory demyelination of CIG through JAK/STAT signaling pathway regulation, including: ① conformed the anti-inflammatory effect of CIG in MOG35-55 induced-EAE model; ②studying the correlation of JAK/STAT signaling pathway activation and neuroinflammation in and the intervention of CIG. Our results will give new insight into the novel immune regulatory of CIG and highlight the great value of this kind of herb compounds in probing the complex signaling network and novel therapeutic targets for autoimmune diseases including MS.

炎性脱髓鞘是多发性硬化（MS）的重要病理特征。前期研究发现山茱萸环烯醚萜苷（CIG）可显著改善EAE大鼠的炎性脱髓鞘以及由此引发的神经功能障碍，然而，其分子机制尚不清楚。Th1和Th17细胞在介导MS发病过程中起主要作用，而Th1和Th17细胞的分化和功能主要受JAK/STAT信号通路调控，由此本项目拟从JAK/STAT角度探讨CIG抗炎性脱髓鞘的分子机制。内容包括：①采用不同蛋白多肽如MOG35-55诱导EAE动物模型，再次确证CIG的作用；②探讨JAK/STAT激活与脑内炎性脱髓鞘的关系及药物CIG的干预作用。以期从胶质细胞炎症反应诱导神经毒性脱髓鞘的理论出发，深入探讨CIG抗炎性脱髓鞘的分子机制、调控炎性脱髓鞘的信号通路、明确CIG的干预靶点。

本项目通过对不同剂量髓鞘少突胶质细胞糖蛋白（Myelin Oligodendrorocyte Glycoprotein, MOG35-55）多肽片段免疫诱导C57BL/6小鼠实验性变态反应性脑脊髓炎（Experimental Autoimmne Encephalomyelitis, EAE）动物模型的摸索，建立MOG（200 μg）诱导的经典小鼠EAE实验动物模型。并初步研究了山茱萸环烯醚萜苷（CIG）对其脑组织JAK/STAT信号通路、胶质细胞活化、BDNF表达的影响。研究结果发现：CIG能够显著改善EAE小鼠的神经功能评分；蛋白免疫印迹（western blot）结果显示CIG能够剂量依赖性抑制脑组织中JAK/STAT信号通路中关键蛋白磷酸化，提示JAK/STAT信号通路参与了CIG的作用；免疫组织化学染色的方法发现：EAE小鼠不同脑区可见神经胶质细胞显著活化（包括星形胶质细胞和小胶质细胞），CIG给药能够抑制疾病高峰期胶质细胞活化；且CIG能够促进脑内脑源性神经营养因子（brain-derived neurotrophic factor, BDNF）在皮层中的表达情况。此外，本项目还建立了体外小胶质细胞活化模型，并初步探索了其活化时JAK/STAT信号通路关键蛋白磷酸化的情况。并意外地发现CIG对LPS/IFN-γ复合诱导小胶质细胞活化模型JAK/STAT信号通路关键蛋白有明显抑制作用，鉴于小胶质细胞激活时呈不同极化状态而发挥双重作用，CIG是否能够调节小胶质细胞的极化及其JAK/STAT分子机制尚不清楚，有待进一步深入研究。本项目共发表基金标注论文5篇（其中SCI 2篇、国内统计源期刊3篇），培养硕士研究生1名，青年学科骨干1名。