二甲双胍通过调节Treg细胞反应治疗实验性自身免疫性脑脊髓炎

Metformin ameliorates the development of experimental autoimmune encephalomyelitis by regulating Treg cell response in mice

目的给予实验性自身免疫性脑脊髓炎(EAE)小鼠应用二甲双胍(MET)干预性治疗。观察MET对EAE小鼠发病情况及体内Treg细胞反应的作用。方法将雌性C57BL/6小鼠随机分为正常对照组、EAE模型组和MET治疗组,采用髓鞘少突胶质细胞糖蛋白MOG35-55免疫小鼠建立EAE模型。自身免疫后第1天开始,按100mg·kg^(-1)·d^(-1)给予MET治疗组腹腔注射。正常对照组及EAE模型组小鼠给予等量的生理盐水每日腹腔注射作为对照。应用Knoz评分观察小鼠的神经功能评分,流式细胞学检测方法检测小鼠脾细胞中Treg细胞比例,ELISA方法检测脾细胞培养上清及血清中IL-10、TGF-β含量。qPCR方法检测小鼠脾及脊髓中Treg细胞转录因子Foxp3 mRNA表达水平。结果与EAE模型组相比,MET治疗组发病程度减轻(P<0.01);脾细胞中Treg细胞比例增高(P<0.01),脾细胞培养上清及血清中IL-10、TGF-β含量增加(P<0.01);脾组织中Foxp3mRNA表达水平升高(P<0.01);脊髓组织中Foxp3mRNA表达水平升高(P<0.01)。结论 MET通过提高外周免疫器官及中枢神经系统的Treg细胞数量,增加抑制炎症因子的表达而达到对EAE模型小鼠的保护作用。

Objective To investigate the preventive effection of metformin（MET）on experimental autoimmune encephalomyelitis （EAE）, and explore the probable mechanism. MethodThe mice were randomly divided into normal control group, EAE model group and MET treatment group, the mice in MET treatment group were treatment group were treated intraperitoneally with 100mg·kg^-1·d^-1 MET from day 1 to the end of the study. Another two groups were injected with vehicle saline only. To examine the infiltration of inflammatory cells in the spinal cords stained with HE in different groups. To explore the different percents of Treg cells in each group with flow cytometry. To examine concentrations of IL-10, TGF-βin supernatants and serum in each groups by ELISA. To detect Foxp3 mRNA transcripts in spleen and spinal cord in each groups using qPCR. Results The clinical scores in MET treatment mice were significantly lower than in EAE mice and there were numerous inflammatory cells in the EAE group compared to the MET treatment group. The percentage of Treg cells in MET treatment mice was significantly higher than EAE mice as determined by flow cytometry. The concentration of IL-10, TGF-βin in supernatants and serum in MET treatment mice is higher than it in EAE group. The level of Foxp3 mRNA transcripts were increased in the spleen and the spinal cord of EAE mice by treatment with MET. ConclusionMET attenuates severity of EAE, and ameliorates the development of EAE by regulating Treg response in peripheral immune organ as well as in central nervous system in EAE.