The Pathologic Study Of The Therapeutic Effect For NDGA And DAN â…¡A On EAE

Objective: Multiple sclerosis (MS) is a chronic inflammatorydemyelinating disease，which happens on the white matter of the centralnervous system (CNS). Its pathogenesis is not clearly yet, in the past few years,studies have shown that not only autoimmunologic factor and environmentalfactor, but also a neural degeneration process results in irreversible damage ofmyelin sheath and axon damage. The damage is thought as the main cause thatleads to the neural functional deficits. Experimental autoimmuneencephalomyelitis(EAE) is recognized as the ideal and suitable animal modelof MS in that its pathogenesis is much likely to human’s, which has thechronic process of acute episode and non-release.In this study, we try to make an EAE model by MOG35-55in C57BL/6mice, with the interference of NDGA and DANIIA, and to observe thetherapeutic effect of the NDGA and DANIIA on EAE by the methods of HEstaining、Luxol Fast Blue myelin staining and Bielschowskys staining.Methods: We used45female C57BL/6mice, inbred strain, aged8-10weeks, weighted18-20g. They were randomly divided into three groups: EAEgroup, DAN group, NDGA group. The mice of the other three groups wereinduced by immunized subcutaneously myelin oligodendrocyte glycoprotein(MOG)35-55emulsified with an equal volume of complete Freund’s adjuvant(CFA) containing Mycobacterium tuberculosis1mg/ml to make EAE models.After we made the EAE model successfully, the DAN group were supposed togive intraperitoneal injections of DAN for20mg·kg-1every day since theirclinical score reached more than one point until sacrificed. The NDGA groupwere imposed intraperitoneal injections of NDGA for10mg·kg-1every daysince their clinical score reached more than one point until sacrificed. TheEAE groups were given intraperitoneal injections of5%DMSO for0.2ml/rat at the same time. The clinical manifestation of the three groups was observed,and the clinical score was assessed. Mice of each group were randomlysacrificed on the0thday,10thday,20thday after treatment. We applied thelumbar intumescentia of the spinal cords to observe the inflammation andmyelin lost and the axon damage. The spinal cords were stained with HE, LFB,Bielschowsky’s. And all data were analyzed by SPSS19.0statistical software.Measurement data were expressed as mean±standard deviation. The statisticalmethod for comparisons of several groups was one-way ANOVA. P value<0.05was considered that it has statistically significance.Results:1Mice conditions and clinical scores of different groups：The average score of clinical manifestation (10thday,20thday aftertreatment) for the mice of DAN and NDGA group to treat the disease wassignificantly lower than EAE group’s. The differences were all significantlystatistical (P<0.05).2HE staining of different groups in lumbar intumescentia of spinal cords2.1Before treatmentThere were inflammatory cells dispersedly on sections of the threegroups.2.210thday after treatmentThere were massive inflammatory cells infiltrated and numerous “bloodvessel muffs” formed on sections of EAE group. There were less “bloodvessel muffs” formed on sections of DAN and NDGA group and theinflammatory cells were mainly around small vessels. The differences of thehistopathological scores had statistically significance(P<0.05).2.320thday after treatmentThe inflammatory cells as well as the “blood vessel muffs” on sections ofEAE group were alleviated, on the other hand, those of DAN and NDGAgroup were vanished. The differences of the histopathological scores hadstatistically significance.(P<0.05).3LFB staining of different groups in lumbar intumescentia of spinal cords On the sections of EAE group, showed there were some thinner myelinsheath and some demyelination area before treatment, also showed thatamount of demyelination area in10thday after treatment and there were nosuch many differences in the20thday after treatment; On the sections ofDAN and NDGA groups, showed smaller demyelination area in the10thdayafter treatment, the myelin sheath became more thicker in the20thday aftertreatment.4Bielschowsky’s staining of different groups in lumbar intumescentia ofspinal cordsOn the sections of EAE group, showed axon damage including axondistortion and swelling before treatment, showed more severe axon damageincluding transaction with the end of ovoid or bulb and even axondisappearance in10thday after treatment and there were no many differences inthe20thday after treatment;On the sections of DAN and NDGA groups,showed smaller axon damage area in both the10thday after treatment andthe20thday after treatment.Conclusions:1DAN and NDGA could alleviate the clinical score of EAE, delay thetime of disease development, and lighten the clinical symptoms of EAE.2DAN and NDGA have the therapeutic effect, which can lessen theEAE animal model’s inflammatory infiltration, promote remyelination,recover axon integrity and neural conductor function.