Impact Of Apolipoprotein E On Astrocyte In Mice With Experimental Autoimmune Encephalomyelitis

Objective To study the impact of apolipoprotein E on astrocyte in mice suffering from experimental autoimmune encephalomyelitis.Methods 20 six-to eight-week-old female C57BL/6 mice were randomly divided into 2 groups, namely E-WT group and C-WT group. And the third group incuded 10 six-to eight-week-old female ApoE-/- mice on a C57BL/6 background, namely E-ApoE-/-group. EAE model was induced by immunized with myelin oligodendrocyte glycoprotein peptides(MOG35-55) in E-WT group and E-ApoE-/-group. The progression of EAE was evaluated every day by a seven-point standardized rating of clinical symptoms. On day 35 after immunization, mice were killed for evaluation of inflammatory infiltration degree of histopathological lesions of EAE. The expression of AQP4 and GFAP was detected by immunohistochemistry using antibodies with anti-AQP4 and anti-GFAP.Results Mice of E-ApoE-/-group exhibited an more serious disease progress of EAE. The maximum clinical score was significantly higher in E-ApoE-/-mice than E-WT mice. In addition, mice of E-ApoE-/-and E-WT group showed more infiltrating cells in the CNS than that in C-WT group. E-ApoE-/-mice significantly reduced the infiltration of immune cells in the CNS relative to E-WT mice. Further more, the expression of AQP4 and GFAP in E-ApoE-/-group and E-WT group was more than C-WT group in brain(P<0.05) and spinal cord(P<0.05). More importantly, the expression of AQP4 and GFAP in the E-ApoE-/-group was significantly beyond the E-WT group in brain(P<0.05) and spinal cord(P<0.05).Conclusions EAE mice exhibit inflammatory cells infiltrating, along with a rise in the water permeability and quantity of astrocyte. ApoE deficienc may aggravate these pathological states in EAE. Our result suggests that the destructive role of ApoE deficienc in EAE by aggravating cytotoxic edema and reactive astrogliosis in mice with experimental autoimmune encephalomyelitis could be another interesting therapeutic target at MS/EAE.