血管活性肠肽在MPTP帕金森病模型小鼠的抗氧化应激作用

Effect of vasoactive intestinal peptide on anti-oxidative stress in the MPTP mouse model of Parkinson's disease

目的:研究血管活性肠肽(VIP)对1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)诱导的帕金森病(PD)模型小鼠发挥抗氧化应激和神经保护作用。方法:雄性C57BL/6J小鼠随机分为生理盐水(NS)组、MPTP组和MPTP+VIP组。Elisa法检测纹状体丙二醛(MDA)以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的变化;免疫组织化学法观察中脑黑质纹状体系统酪氨酸羟化酶(TH)、星形胶质细胞特异性标记物胶质细胞纤维酸性蛋白(GFAP)和小胶质细胞标志物离子钙结合蛋白(Iba-1)的表达变化;透射电子显微镜观察中脑黑质多巴胺能神经元的超微结构变化。结果:MPTP组与对照组相比,MDA水平显著增高,SOD和CAT的表达显著降低;给予VIP可显著抑制MDA的水平(P<0.01),增强SOD和CAT的表达(P<0.05)。与对照组相比,MPTP组小鼠GFAP和Iba-1的表达明显上升,TH表达明显下降;给予VIP可显著降低GFAP和Iba-1的表达(P<0.05),而TH表达明显增强。透射电镜观察显示:NS组神经细胞和细胞器结构清晰完整;MPTP组神经细胞核膜内陷,线粒体空泡样变;MPTP+VIP组神经细胞和细胞器结构基本正常。结论:VIP能够抑制MPTP诱导PD小鼠中脑黑质星形胶质细胞和小胶质细胞的活化,对抗氧化应激,发挥神经保护作用。

Objective： To investigate the effect of vasoactive intestinal peptide （VIP） on anti-oxidative stress and neuroproteetive role in MPTP-induced mouse model of Parkinson＇s disease. Methods： Male C57BL/6J mice were randomly divided into saline group （ NS）, MPTP group and MPTP ＋ VIP group. Elisa was used to detect the expression of malonal- dehyde（MDA）, superoxide dismutase （SOD）and catalase （CAT） in striatum. The expression of tyrosine hydroxylase （TH）, glial fibrillary acidic protein（GFAP） and ionized calcium-binding adaptor molecule-1 （Ibal） in the nigrostriatal dopaminergic system of mice were mesured by immunohistochemistry. And the ultrastructural changes of dopaminergic neurons in substantia nigra were observed by transmission electron microscopy. Results： Compared with that the NS group, the level of MDA was significantly increased, and the expression of SOD and CAT were significantly decreased in striatum of MPTP induced mice. VIP treatment reversed the MPTP-induced abnormal level of MDA（ P 〈 0.01 ）, CAT and SOD（ P 〈 0.05 ）. Compared with that the NS group, the expression of Iba-1 and GFAP in the substantia nigra was significantly increased, but the number of DA neurons markedly decreased by immunohistochemical staining. Noticeably, VIP treatment protected the expression of TH in the nigrostriatal system, evidently restrained the activation of microglia and astrogliosis in the substantia nigra of MPTP induced mice （ P 〈 0.05 ）. The transmission electron microscopy results showed that the uhrastructure of the neurons and organelles in the control mice were clear and complete. In the model group, the nuclear membrane was invaginated, and the mitochondria were vacuole-like shaped. The neurons and organelles in MPTP ＋ VIP group were near normal. Conclusion： VIP can inhibit astrocytic and microglial activation, show anti-oxidative stress and neuroproteltion role in nigrostriatal system.