Effect of vasoactive intestinal peptide on prevention and treatment of experimental autoimmune encephalomyelitis rats by regulating the levels of IFN-γand IL-17A in brain tissue / 军事医学

ABSTRACT

Objective To explore the effect of vasoactive intestinal peptide ( VIP) on the prevention and treatment of experimental autoimmune encephalomyelitis(EAE) rats by regulating the levels of IFN-γand IL-17A in brain tissue. Methods Sixty healthy female Wistar rats were randomly divided into 4 groupsnormal control group, EAE control group, VIP low-dose group and VIP high-dose group.Myelin basic protein ( MBP)+complete Freurd′s adjuvant ( CFA) was used to establish an EAE model.The low and high-dose VIP groups were intraperitoneally injected with VIP 4 nmol/kg(0.2 ml) and 16 nmol/kg (0.8 ml) respectively every other day,while normal control group and EAE group with 0.8 ml saline for ten consecutive days.The incubation period, progression and peak of neurological dysfunction score ( NDS) changes of rats were recorded.The pathological changes, the GFAP+astrocyte activation in the brain at the morbidity peak of rats and the cytokine levels of IFN-γand IL-17A in brain tissue were observed.Results The incubation period was extended, the progression and peak NDS were shortened in the two VIP groups.In normal control group, there was no inflammatory cell infiltration or active astrocytes in brain tissue.The degree of infiltration of inflammatory cells and the degree of astrocyte activation in the VIP control group were significantly lower than in the EAE group.The cytokine levels of IFN-γand IL-17A in brain tissue were reduced in VIP groups.Conclusion By lowering IFN-γand IL-17A content in brain tissue, the infiltration of inflammatory cells and astrocyte activation are inhibited.VIP plays an important role in prevention and control of EAE.