| Objective: This study was to investigate the neuroprotective effect of microglial activation in experimental autoimmune encephalomyelitis(EAE).Methods: EAE was induced by immunization with MOG35–55 and then randomly divided into control group, EAE group and Tuftsin group. On day 1 after MOG35-55 immunization Tuftsin group mice were injected with Tuftsin(20ul/d, total 200ul)subcutaneously, and the EAE group, control group were injected with PBS. At least two investigators weighed and evaluated the animals for clinical score in a blinded way. After immunization 7,14,21 and 28 days executed the mice, then performed histological staining include Luxol Fast Blue stain and immunohistochemistry,observed and compared the experimental mice pathological changes. What's more,we performed quantitative real-time PCR to test the concentration of IL-10, TNF-?,TGF-? and western blot to detect the content of iba-1.Result: 1. Control group mice were not found in nerve dysfunction; EAE group and Tuftsin group were onset after 10 days and 12 days, respectively, and after 21 days to the peak incidence;Compared EAE group with Tuftsin group, the clinical symptoms of the mice was more serious, and the average clinical score was significantly higher than that of Tuftsin group, and P<0.05.2. None of the groups exhibited significant demyelination on day 7. At clinical onset point, the LFB staining of EAE group showed slight demyelination in the white matter. But in Tustsin group, the result of demyelination is relatively integrity contrast with EAE group at the the same time. At the peak of EAE process, gradually,an obviously varition of myelin sheath is severe deficience in EAE group. In contrast,the result of demyelination is milder in Tuftsin group. When the time is to recovey stage of EAE, the loss of myelin is not continue but starting remyelination,particularly in Tuftsin group, which remyelination is more obvious than EAE group,presenting the structure of myelin sheath is relatively intact. It should be pointed out that the structure of myelin in control group is maintained constant consistently.3. At the same time comparison the concentration of cytokines in different groups: At day 14, 21, 28, the amounts of IL-10 and TGF-b in Tuftsin group were higher than that in EAE group, but the level of TNF-a were less than EAE group.4. We compared the expression levels of iba-1 in all groups via western blot at different time point of EAE course. The control group had a small amount of Iba-1expression and without any significant changes in different time. The expression of iba-1 in EAE group, Tuftsin group and normal control group had no difference before onset. At onset, the expression of iba-1 in EAE group and Tuftsin group were also significantly increased, and Tuftsin group is higher than that of EAE group. What's more, increases of iba-1 expression in the brain of Tuftsin group compared with that in EAE group on day 21, day 28.Conclusion:1. The incidence in the Tuftsin group was low and the clinical scores were low, and the rate of recovery was higer.2. The degree of demyelination of spinal cord in Tuftsin group was light.3. Diminishing the inflammation cytokine and enhancing anti-inflammation cytokine by Tuftsin.4. Tufusin can promote the activation of microglia and phagocytic activity.5. Transforming into an anti-inflammatory phenotype M2 from the pro-inflammatory phenotype M1 could play a protective role in EAE. |
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