血管活性肠肽(VIP)对实验性自身免疫性脑脊髓炎(EAE)大鼠脑组织IL-17A含量的影响

目的探讨血管活性肠肽(vasoactive intestinal peptide,VIP)对实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)大鼠脑组织IL-17A含量的影响。方法 60只健康雌性Wistar大鼠随机分成正常对照组、EAE对照组、VIP低剂量防治组和VIP高剂量防治组。利用髓鞘碱性蛋白(MBP)+完全福氏佐剂(CFA)诱导建立EAE模型。自造模当日起,每隔一日分别对VIP低、高剂量防治组大鼠腹腔注射VIP 4nmol/kg(0.2 m L)、16 nmo L/kg(0.8 m L),正常对照组及EAE对照组注射0.8 m L生理盐水,连续10 d。观察大鼠发病情况;ELISA法检测脑组织匀浆中IL-17A因子含量变化;免疫组化技术,利用抗胶质纤维酸性蛋白抗体(GFAP)检测脑组织内的星型胶质细胞活化情况。结果 VIP各剂量防治组大鼠发病潜伏期延长、进展期缩短、发病高峰期神经功能障碍评分(NDS)降低,脑组织匀浆中IL-17A含量降低,活化的星型胶质细胞即GFAP~+细胞量减少,且各剂量组间存在一定剂量依赖关系。结论 VIP通过降低脑组织中IL-17A含量、抑制星型胶质细胞活化,发挥对EAE的防治作用。

Effect of vasoactive intestinal peptide (VIP) on the content of IL-17A in the brain tissue of rats with experimental autoimmune encephalomyelitis (EAE)

Objective To explore the effect of vasoactive intestinal peptide (VIP) on the content of IL-17A in the brain tissue of rat models of experimental autoimmune encephalomyelitis (EAE). Methods Sixty healthy female Wistar rats were randomly divided into normal control group, EAE control group, low-dose VIP group and high-dose VIP group. Ten healthy guinea pigs were used to prepare anti- IL-17A antibody. Myelin basic protein (MBP)+complete adjuvant (CFA) were used to establish the EAE model. Since the first day of modelling, the low-dose and high-dose VIP groups received intraperitoneal injection of VIP 4 nmol/kg (0.2 mL) and 16 nmol/kg (0.8 mL), respectively, every other day for 10 consecutive days. The normal control group and EAE group were injected with 0.8 mL saline instead of VIP. The incubation period, progression and the peak of neurological dysfunction scores (NDS) of the rats were recorded. The levels of IL-17A in the brain tissue was determined by ELISA assay, and the GFAP⁺astrocyte activation in brain at morbidity peak in the rats was examined using anti-GFAP (glial fibrillary acidic protein) antibodies. Results The incubation period were extended, the progression period was shortened and the peak neuological dysfunction score (NDS) was decreased in the VIP-treated groups, in a dose-response relationship. The cytokine levels of IL-17A and the astrocyte activation degree in brain tissue were reduced in each VIP dose group, in a dose-response relationship. Conclusions VIP exerts therapeutic effect on experimental autoimmune encephalomyelitis through lowering the IL-17A content and inhibition of astrocyte activation in the brain tissue.