Th17介导的自身免疫反应在神经病理性疼痛发病中的分子机制

The contribution of Th17 to the pathogenesis of neuropathic pain is unclear. Our previous study has preliminarily confirmed the contribution of autoimmune reaction to the neuropathic pain triggered by nerve injury, and its manifestations are related with the proliferation of Th17.These results have been published in Anesthesiology (Jing Li, et al. Anesthesiology 2013). However, it is unknown how Th17 participates in the pathogenesis of neuropathic pain. Myelinated nerve fibers mainly composed by Schwann cells in the peripheral neural tissue decreased obviously after nerve injury. Therefore, we hypothesized that Th17 most likely attack the Schwann cells on the surface of myelinated nerve fibers. On the basis of our previous studies, we attempt to treat SD rats with siRNA interference and intrathecal catheter injection technology, and observe pain behavior changes in the CCI model, and detect lymphocyte subtypes and their cytokine. Additionally, Th17 from neuropathic rats and normal Schwann cells would be co-cultured in vitro. Subsequently, apoptosis of Schwann cells and lymphocyte cytokines levels in the culture medium would be detected in this study. Thus, we attempt to investigate the molecular mechanisms of Th17 contributing to the neuropathic pain triggered by nerve injury, and provide a theoretical basis for the search of new therapies, and improve the outlook for patients with neuropathic pain.

Th17在神经病理性疼痛发病机制中的作用尚不清楚。我们前期研究发现神经病理性疼痛的维持与Th17浸润有关(Anesthesiology,2013）。但Th17导致神经病理性疼痛的靶细胞分子机制不清楚，我们推测可能与神经损伤诱发的针对神经组织的Th17相关的自身免疫反应有关。神经损伤后主要由Schwann细胞组成的有髓神经纤维的减少最为明显，因此其表面的Schwann细胞最可能为Th17免疫攻击的主要成分。本课题拟在前期研究的基础上，采用鞘内置管技术，通过siRNA干扰及鞘内注射对SD大鼠进行处理，观察CCI模型疼痛行为学变化，并检测淋巴细胞亚型及其细胞因子；结合体外诱导分化Th17技术，将诱导分化的Th17与Schwann细胞共培养，检测Schwann细胞凋亡及培养液中的淋巴细胞因子水平，探讨Th17在神经病理性疼痛发病过程中导致免疫损伤的靶细胞及分子机制，为寻找新的治疗方法提供理论依据。

神经性病理性疼痛是继发于外周或中枢神经系统损伤后的一种慢性疾病状态，不仅症状严重，发病率高，更无有效治疗。近期研究提示：神经病理性疼痛的维持与Th17浸润有关，但Th17导致神经病理性疼痛的靶细胞分子机制不清楚，本研究的目的是探讨Th17在神经病理性疼痛发病过程中导致免疫损伤的靶细胞及分子机制，为寻找新的治疗方法提供理论依据。健康成年雄性SD 大鼠60只，体重约200～250 g，实验前禁食12 h，自由饮水。随机分为6组： CCI+IL-17 siRNA重组慢病毒（C1），CCI+空载体组（C2），CCI+生理盐水组（C3），Sham+ IL-17 siRNA重组慢病毒（S1），Sham+空载体组（S2），Sham+生理盐水组（S3）。并利用iTaq蛋白组学分析技术初步研究该病理过程的发病机制。本研究成功构建了IL-17 siRNA重组慢病毒载体，并经疼痛行为学观察验证成功复制了CCI大鼠神经病理性疼痛模型。本研究发现Th17在神经病理性疼痛发病中具有重要作用。IL-17在神经病理性疼痛损伤坐骨神经组织中呈高表达，iTaq蛋白组学分析显示：IL-17可能通过ECM受体信号途径活化PI3K，激活TRAF6、NF-κB等信号通路导致神经系统炎症，进而导致神经损伤，参与了神经病理性疼痛的发病。