槲皮素对Aβ25-35致PC12细胞损伤的雌激素样保护作用及分子机制

Research on estrogen-like protective effect of quercetin on PC12 cells induced by Aβ25-35 and molecular mechanism

目的 以Aβ 25-35 诱导PC12细胞损伤,建立阿尔茨海默病体外模型,探讨槲皮素(quercetin,Que)的雌激素样保护作用及分子机制。方法 MTT法检测细胞活力;免疫荧光染色检测雌激素受体两种亚型ERα和ERβ的表达;Western blot检测ERα、ERβ,以及p-Akt、total-Akt、p-GSK-3β、total-GSK-3β蛋白表达量的变化。结果 MTT结果显示, 20 μmol·L -1 的Aβ 25-35 作用PC12细胞24 h后,能明显降低细胞的存活率( P <0.01);Que(40、60、80 μmol·L -1 )组与模型组相比,能明显增加细胞的存活率( P <0.05);免疫荧光染色和Western blot结果显示,与模型组相比,Que明显提高ERα、p-Akt、p-GSK-3β蛋白表达量( P <0.01),ERβ蛋白表达虽有增加,但差异无显著性( P >0.05),而各实验组total-Akt和total-GSK-3β蛋白表达量基本无变化。当雌激素受体受到ICI182,780抑制后,PC12细胞活力及p-Akt、p-GSK-3β蛋白表达明显下降( P <0.01)。结论 槲皮素对Aβ 25-35 诱导的PC12细胞损伤具有保护作用,其雌激素样神经保护作用机制是通过ERα介导激活PI3K/Akt/GSK-3β信号通路。

Aim To investigate the estrogen-like protective effect of quercetin and its molecular mechanism via the establishment of a model of AD in vitro by inducing PC12 cells with Aβ 25-35 . Methods Cell viability was detected by MTT assay. The expressions of ERα and ERβ were detected by immunofluorescence staining. The expressions of ERα and ERβ, p-Akt, total-Akt, p-GSK-3β and total-GSK-3β related proteins were assessed by Western blot. Results MTT assay showed that 20 μmol·L -1 Aβ 25-35 could significantly reduce cell viability after treatment with PC12 cells for 24 h ( P <0.01). Compared with model group, quercetin(40, 60, 80 μmol·L -1 )could significantly increase the cell survival rate ( P <0.05). Immunofluorescence and Western blot results showed that quercetin could increase the ERα, p-Akt and p-GSK-3β protein expression ( P <0.05), and the expression of ERβ protein was elevated without significant difference ( P >0.05). The expression levels of total-Akt and total-GSK-3β protein remained basically unchanged. When the estrogen receptor was inhibited by ICI182,780, the cell viability of PC12 cells and the expression of p-Akt and p-GSK-3β protein were significantly decresed ( P <0.01). Conclusion All the results indicate that quercetin has a protective effect on Aβ 25-35 induced PC12 cell injury. The estrogen-like neuroprotective mechanism is able to activate PI3K/Akt/GSK-3β signaling pathway by the mediation of estrogen receptor alpha.