槲皮素对Aβ25-35介导的线粒体凋亡途径及p38MAPK信号通路的影响

Effects of quercetin on Aβ25-35-mediated mitochondrial apoptosis pathway and p38MAPK signal pathway

目的:研究槲皮素通过p38MAPK信号通路调节Aβ25-35引起PC12细胞线粒体损伤的作用。方法:20μmol·L^(-1)的Aβ25-35作用PC12细胞作为AD细胞毒性损伤模型,0.1μmol·L^(-1)的17β-雌二醇(17β-estradiol,17β-E2)和50μmol·L^(-1)金雀异黄素(Genistein,Gen)作为阳性对照药,分别给予低剂量槲皮素(40μmol·L^(-1))、中剂量槲皮素(60μmol·L^(-1))和高剂量槲皮素(80μmol·L^(-1)),同时设定SB203580(p38MAPK特异性抑制剂)预处理组(Aβ25-35+10μmol·L^(-1)SB203580)。线粒体荧光探针(Mito-Tracker-red)检测线粒体形态;JC-1检测线粒体膜电位;荧光素酶发光法检测ATP含量;免疫荧光染色法检测pp38MAPK蛋白的表达;Western blot法测定Bcl-2、Bax、p-p38MAPK/p38MAPK和Cytochrome C(Cyt C)蛋白的表达。结果:与Aβ模型组相比,槲皮素可显著提高线粒体膜电位和ATP含量,保护线粒体形态;免疫荧光显示,槲皮素显著抑制p38MAPK磷酸化表达。Western blot显示槲皮素上调Bcl-2蛋白表达及下调Bax、p-p38 MAPK/p38MAPK、Cyt C蛋白的表达(P<0.05);当p38MAPK被SB203580抑制后,Bax、Cyt C蛋白表达降低(P<0.01),Bcl-2蛋白表达升高(P<0.01)。结论:槲皮素可通过介导p38MAPK信号通路抑制Aβ25-35诱导的线粒体凋亡,进而发挥神经保护效应。

OBJECTIVE To investigate the effect of quercetin(Que)on mitochondrial damage induced by Aβ25-35 through p38MAPK signaling pathway in PC12 cells.METHODS PC12 cells were treated with Aβ25-35(20μmol·L^(-1))as a model of AD cell toxicity,and 0.1μmol·L^(-1) of 17β-estradiol(17β-E2)and 50μmol·L^(-1) of genistein(Gen)served as positive controls,lowdose Que(40μmol·L^(-1)),medium-dose Que(60μmol·L^(-1))and high-dose Que(80μmol·L^(-1))were used in this experiment.And select the SB203580(p38MAPK specific inhibitor)as pretreatment group(Aβ25-35+10μmol·L^(-1) SB203580).Mito-Tracker-red detects Mitochondria morphology;JC-1 detects mitochondrial membrane potential and luciferase luminescence detects ATP;Immunofluorescence staining detects the expression of p-p38MAPK protein.Western blot method determines the expression of Bcl-2,Bax,p-p38MAPK/p38MAPK and Cytochrome C(Cyt C)protein.RESULTS Compared with the model group,quercetin significantly increased mitochondrial membrane potential and ATP content,and protected mitochondrial morphol⁃ogy.Quercetin significantly inhibited the phosphorylation of p38MAPK.Western blot showed that quercetin up-regulated the expression of Bcl-2 protein and down-regulated the expression of Bax,p-p38MAPK/p38MAPK and Cyt C protein(P<0.05).When p38MAPK was inhibited by SB203580,compared with the model group,the expression of Bax and Cyt C protein decreased(P<0.01),while the expression of Bcl-2 protein increased(P<0.01).CONCLUSION Quercetin can inhibit A by mediating the p38MAPK signaling pathwayβmitochondrial apoptosis induced by 25-35 exerts neuroprotective effects.