外源性H2S对帕金森病模型小鼠神经保护作用及其对基质金属蛋白酶9和Caspase-1表达的影响

Neuroprotective effect of exogenous hydrogen sulfide and the expression of matrix metalloproteinases-9 and Caspase-1 in mice model of Parkinson's disease

目的 探讨外源性硫化氢(H2S)对1-甲基-4-苯基-1, 2, 3, 6-四氢吡啶(MPTP)对诱导的帕金森病(PD)小鼠保护作用及其对基质金属蛋白酶9(MMP-9)和Caspase-1表达的影响。方法 将36只雄性昆明小鼠随机分为对照组(control)、PD组和PD+硫氢化钠(NaHS)组,每组12只。腹腔注射MPTP(30 mg/kg),每天1次,连续7 d诱导PD小鼠模型,PD+NaHS组于模型制作前30 min腹腔注射5.6 mg/kg NaHS(H2S供体),对照组给予等量生理盐水。采用震颤麻痹评分、悬挂实验评估小鼠行为学变化,HE染色观察各组小鼠中脑黑质(SN)神经元的形态学改变;免疫组织化学和Western blotting法检测各组中脑SN区酪氨酸羟化酶(TH)、MMP-9和Caspase-1蛋白表达。结果 与control组比较,PD组小鼠震颤麻痹评分增高(P<0.05),悬挂实验评分降低(P<0.05);光学显微镜下中脑SN区神经元数量明显减少,排列紊乱,部分神经元胞体固缩,胞质红染;SN区TH阳性细胞数及TH蛋白表达降低(P<0.05),MMP-9与Caspase-1阳性细胞数及MMP-9与Caspase-1蛋白表达水平增加(P<0.05)。与PD组相比,PD+NaHS组小鼠震颤麻痹评分降低(P<0.05),悬挂实验评分增加(P<0.05),SN区神经元数量明显增多;SN区TH阳性细胞数及TH蛋白表达水平增加(P<0.05),MMP-9与Caspase-1阳性细胞数及MMP-9与Caspase-1蛋白表达水平降低(P<0.05)。结论 外源性H2S对PD小鼠黑质多巴胺能神经元具有保护作用,其机制可能与抑制MMP-9与Caspase-1介导的神经炎症反应有关。

Objective To investigate the protective effect of exogenous hydrogen sulfide(H,S)on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)induced Parkinson's disease in mice and the effect on the expression of matrix metalloproteinase-9(MMP-9)and Caspase-1.Methods Totally 36 male Kunming mice were randomly divided into control group,PD group and PD+sodium hydrosulfide(NaHS)group,with 12 mice in each group.PD groupwas intraperitoneally injected with MPTP(30 mg/kg),once a day,for 7 consecutive days to induce Parkinson's disease mouse model.PD+NaHS group was intraperitoneally injected with 5.6 mg/kg NaHS(donors of H,S)30 minutes before modeling,and control group was given the same amount of normal saline.The behavioral changes of mice were evaluated by tremor paralysis score and suspension test,and the morphological changes of neurons in the substantia nigra(SN)were observed by HE staining.The expressions of tyrosine hydrogenase(TH),MMP-9 and Caspase-1 in the SN were detected by immunohistochemistry and Western blotting.Results Compared with the control group,the score of tremor paralysis in PD group increased(P<0.05),and the score of suspension test decreased(P<0.05).Under the light microscope,the number of neurons in the SN decreased significantly,and the arrangement was disordered.The number of TH positive cells and TH protein expression in the SN decreased(P<0.05),while the number of MMP-9 and Caspase-1 positive cells and the expression levels of MMP-9 and Caspase-1 increased(P<0.05).Compared with the PD group,the tremor paralysis score in PD+NaHS group decreased(P<0.05),the suspension test score increased(P<0.05),and the number of neurons in the SN increased significantly.The nunber of TH positive cells and TH protein expression levels in the SN increased(P<0.05),while the number of MMP-9 and Caspase-1 positive cells and the expression levels of MMP-9 and Caspase-1 decreased(P<0.05).Conclusion Exogenous hydrogen sulfide has a protective effect on dopaminergic neurons in the SN of PD mice,which might be related to the inhibition of MMP-9 and Caspase-1 mediated neuroinflammatory response.