miR-1896对EAE小鼠T细胞亚群的调控及炎性因子生成的影响

Effects of miR-1896 on T lymphocyte subsets and inflammatory cytokines production in EAE mice

目的探讨在活化的星形胶质细胞和实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)小鼠中共上调的miR-1896对EAE小鼠CD4^+T细胞亚群的调控作用及促炎因子生成的影响。方法构建特异性靶向星形胶质细胞的miR-1896过表达与沉默的重组慢病毒载体,分别命名为LV-miR-1896和LV-miR-1896-sponge,并包装病毒悬液,注射入C57/B6小鼠体内7 d后,髓鞘少突胶质细胞糖蛋白35-55(MOG_(35-55))多肽诱导EAE模型。采用双盲法每日对小鼠进行神经功能评分;流式细胞术测定小鼠T淋巴细胞亚群数量的变化;Real-time PCR及ELISA检测小鼠脊髓组织及血清中炎性因子的产生水平。结果 miR-1896过表达增强了EAE小鼠的神经功能评分,临床症状加重;沉默内源性星形胶质细胞miR-1896的表达,减少了EAE小鼠Th1、Th17细胞的数量,增加了Treg细胞的数量,同时降低了促炎因子的产生。结论星形胶质细胞活化后异常表达的miR-1896通过调控EAE小鼠CD4^+T细胞亚群的数量及促炎因子的生成,从而调节了EAE的疾病进程。

This study was performed to explore the effect of miR-1896 up-regulated both in activated astrocytes and experimental autoimmune encephalomyelitis（EAE） on CD4~＋T cell subsets and proinflammatory cytokines production in EAE mice. Recombinant lentivirus vectors of miR-1896 overexpression and inhibitor were constructed, which were specifically targeted astrocytes, and were named as LV-miR-1896 and LV-miR-1896-sponge, respectively. Meantime, the recombinant lentivirus vectors were packaged to viral suspension, and the EAE model was induced by MOG_（35-55） after viral suspension injecting for 7 days. The neurological function score of mice was evaluated by double-blind method, and the numbers of T cell subsets were determined by flow cytometry.Furthermore, the levels of inflammatory cytokines in spinal cord tissue and serum of mice were detected by Realtime PCR and ELISA. Data revealed that the overexpression of miR-1896 enhanced the neurological function score and aggravated EAE. However, silencing miR-1896 in astrocytes decreased the numbers of Th1 and Th17 cells, increased the numbers of Treg cells in EAE mice, and decreased the production of proinflammatory cytokines significantly in spinal cords of EAE mice. In summary, our study suggests that the abnormal expression of miR-1896 in activated astrocytes affect the process of EAE through regulating the numbers of CD4~＋T cell subsets and the production of proinflammatory cytokines.