β-榄香烯对EAE小鼠视神经炎治疗作用的研究

The effect on the optic neuritis of EAE mice treated by β-elemene

目的:研究β-榄香烯(β-elemene)对实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)小鼠视神经炎的治疗作用;明确β-榄香烯如何通过对辅助性T细胞亚群的分化调节及其特异性细胞因子的转录调节实现其治疗作用。方法:通过行为学、组织形态学技术观察β-榄香烯对EAE小鼠脱髓鞘性视神经炎的治疗作用,进一步通过ELISA及定量PCR技术观察β-榄香烯对辅助性T细胞亚群特异性细胞因子及转录因子的蛋白及mRNA表达的影响。结果:β-榄香烯能改善EAE小鼠的神经功能评分(与对照组比较,P<0.05);β-榄香烯能减轻EAE小鼠视神经轴索及髓鞘损伤;免疫后11天,β-榄香烯可减少EAE小鼠视神经细胞因子白细胞介素-17(IL-17)、转录因子孤儿核受体(RORγt)的蛋白及mRNA的表达(与对照组比较,P<0.05);同时增加叉头蛋白3(Foxp3)mRNA的表达(与对照组比较,P<0.05)。免疫后19天,β-榄香烯可减少EAE小鼠视神经细胞因子γ-干扰素(IFN-γ)、转录因子T-bet的蛋白及mRNA的表达(与对照组比较,P<0.05);并维持Foxp3mRNA的较高水平表达(与对照组比较,P<0.05)。结论:β-榄香烯可减轻EAE小鼠视神经的炎症损伤;β-榄香烯可通过调节辅助性T细胞亚群的分化维持机体的免疫平衡。

Objective：To study the neuroprotective effect of β-elemene on optic neuritis of EAE mice,and to identify how β-elemene regulates the differentiation of T helper cell subsets and the production of their specific cytokines to implement the neuroprotective effect.Methods：The neuroprotective effect of β-elemene on demyelinated optic neuritis of EAE mice was observed through the behavior and morphology method（hematoxylin-eosin staining,electromicroscope observation）.The mRNA and protein expressions of specific cytokines and their transcript factors were observed by ELISA and real time PCR with T helper cell subsets of the EAE mice as the samples.Therapeutic effect of β-elemene was therefore evaluated.Results：β-elemene can improve clinical score and reduce axonal and myelin damage in EAE mice.β-elemene can reduce the expression of cytokine IL-17 and the transcript factor RORγt on 11 days after immunization,and at the same time increased the expression of Foxp3.β-elemene also downregulated the expression of cytokine IFN-γ and its transcript factor T-bet on 19 days after immunization,and the drug kept the expression of Foxp3 mRNA higher during the period.Conclusion：β-elemene can improve inflammatory injury of optic neuritis in EAE mice,and keep immune homeostasis by controlling the differentiation of T helper cell subsets.