氯喹对EAE模型小鼠神经元损伤的影响

目的观察氯喹对实验性自身免疫性脑脊髓炎(EAE)小鼠脊髓神经元存活的影响,并探讨相关机制。方法采用髓鞘少突胶质细胞糖蛋白35-55(MOG35-55)诱导C57BL/6小鼠建立EAE模型,造模成功后给予氯喹干预。应用Knoz法进行临床评分,脊髓腰膨大节段石蜡包埋、冠状切片,行苏木精-伊红、LFB和Nissl染色,分别观察各组小鼠脊髓炎症反应、髓鞘脱失和神经元存活情况。脊髓腰膨大冷冻切片,行免疫荧光双标染色。同时提取脊髓腰膨大组织蛋白检测凋亡相关蛋白表达。结果氯喹缓解EAE小鼠临床症状,减轻脊髓炎性细胞浸润、髓鞘脱失、以及神经元死亡和损伤。与对照组相比,氯喹治疗组脊髓Bax水平降低,Bcl-2水平升高,Bax/Bcl-2比值降低。Neu N与Bcl-2荧光共定位明显增强。结论氯喹可能通过调节中枢神经系统前凋亡蛋白水平、上调神经元Bcl-2表达,从而减轻EAE小鼠神经元损伤以及神经功能缺失症状,发挥神经保护作用。

The effect of chloroquine on neuron injury in experimental autoimmune encephalomyelitis

Objective To investigate the effect on neuronal injury of chloroquine(CQ)in the treatment of experimental autoimmune encephalomyelitis(EAE). Method EAE was induced in C57BL/6 mice by immunization with MOGp35-55. CQ was administered to mice after establishment of EAE. Mice were examined daily for clinical signs of EAE and scored as follows Knoz. The fixed specimen of lumbar spinal cord at 20d after immunization were taken and made continuous 30 μm sections. HE, LFB and Nissl staining were performed for investigate the inflammatory, demyelination and neuron loss in the spinal cords of each groups. Freezing sections for immunoflunce double staining. The expression of pro-apoptosis protein in the lumber spinal cords was detected by Western-blot analysis. Results Compared with the EAE-vehicle group, mice treated with CQ exhibited ameliorated clinical signs, decreased the degree of inflammatory and myelin loss, increased the numbers of Nissl-stained cells in EAE. CQ treatment obviously up-regulated Bcl-2 level, the number of Bcl-2-positive neurons with some down-regulation of Bax, the ratio of the Bax to Bcl-2 was reduced. Conclusion CQ plays a neuroprotective role by modulating the expression of pro-apoptosis proteins of central nerve system(CNS).