黄芪糖蛋白对实验性自身免疫性脑脊髓炎小鼠血脑屏障作用的研究

Effects of Huangqi Glycoprotein on the Blood Brain Barrier in Mice with Experimental Autoimmune Encephalomyelitis

目的观察黄芪糖蛋白(HQGP)对C57BL/6小鼠实验性自身免疫性脑脊髓炎(EAE)血脑屏障(BBB)的影响,探讨HQGP治疗EAE的机制。方法选择C57BL/6雌性小鼠40只,用髓鞘少突胶质细胞糖蛋白35-55(MOG35-55)诱导建立EAE模型,并随机分为HQGP组和EAE组。HQGP组于免疫后第3天腹腔注射HQGP(1 mg/kg),EAE组每天给予等量生理盐水,直至免疫后第18天处死。观察小鼠的发病情况;检测小鼠脑组织含水量和伊文思蓝(EB)含量;免疫组织化学法检测小鼠脊髓组织中CD4+T细胞和CD68+巨噬细胞的浸润;Western blotting检测脊髓组织BBB紧密连接蛋白Occludin、ZO-1的表达。结果与EAE组比较,HQGP组发病延缓,临床症状轻,脑组织含水量及EB含量降低。HQGP能降低小鼠脊髓组织中CD4+T细胞和CD68+巨噬细胞的浸润,显著增加脊髓组织中Occludin及ZO-1的表达。结论HQGP可以有效保护EAE小鼠的BBB,进而减轻EAE的临床症状。

Objective To observe the effect of Huangqi glycoprotein(HQGP)on the blood brain barrier(BBB)in C57BL/6 mice with experimental allergic encephalomyelitis(EAE)and explore the mechanisms of action of HQGP in the treatment of EAE.Methods Forty female C57BL/6 mice were immunized subcutaneously with myelin oligodendrocyte glycoprotein peptide 35-55(MOG35-55)and divided into an HQGP-treated group and an EAE control group.The HQGP-treated group was injected intraperitoneally with 1 mg/(kg·d)of HQGP,and the EAE group was injected with an equal volume of saline daily from day 3 to 18 post-immunization(p.i.).The water and Evans blue(EB)content of each brain were determined.Spinal cords were harvested for H and E staining,myelin staining.The expression of CD4+T cells and CD68+macrophages was detected by immunofluorescence.Occludin and ZO-1 expression in spinal cords was detected by Western blotting.Results HQGP treatment delayed onset of EAE and attenuated clinical symptoms.Water and EB levels were significantly lower in the brains of the HQGP-treated group than in the EAE group.HQGP significantly decreased CD4+T cells and CD68+macrophages cell infiltration in the central nervous system.HQGP also increased the expression of Occludin and ZO-1 in the spinal cord.Conclusion HQGP can relieve the clinical symptoms of EAE by maintaining the integrity of the BBB.