柴胡皂苷D抑制Aβ_(25-35)诱导PC12细胞tau蛋白过度磷酸化

Saikosaponin D Inhibiting Phosphorylation Level of Tau Protein in PC12 Cells Challenged to AΒ_(25-35)

目的:探究柴胡皂苷D(SSD)对Aβ诱导大鼠肾上腺嗜铬细胞瘤细胞(PC12)tau蛋白磷酸化水平的影响。方法:将PC12细胞分为3组:对照组,用DMEM培养基常规培养;Aβ组,用含有10μmol/L Aβ25-35的DMEM培养基培养PC12细胞;SSD组,选择含有4μg/m L SSD+10μmol/L Aβ25-35的DMEM培养基共同培养PC12细胞,24 h后收集各组细胞;利用Western blot技术,检测对照组、Aβ组和SSD组PC12细胞中tau mRNA表达及蛋白表达水平的变化。结果:与对照组细胞相比,Aβ处理组tau蛋白磷酸化水平显著升高(P<0.05);而SSD组细胞tau蛋白磷酸化水平无明显改变(P>0.05);同时,与对照组相比较,Aβ处理组和SSD处理组细胞tau mRNA表达水平无明显变化(P>0.05),tau总蛋白水平无明显变化(P>0.05)。结论:在PC12细胞中,SSD可抑制Aβ25-35诱导PC12细胞tau蛋白的过度磷酸化。

Objective： To explore the effect of Saikosaponin D（ SSD） on the expression and phosphorylation levels of tau protein in the PC12 cells and the related mechanisms. Methods： The PC12 cells were divided into 3 groups： control group,Aβ group and SSD group. The control group was cultured with conventional culture medium DMEM. Aβ group wascultured with DMEM containing 10 μmol / L Aβ25- 35 and SSD group cultured with DMEM culture medium containing 4μg / m L SSD ＋ 10 μmol /L Aβ25- 35. After 24 hours in culture,cells in each group were collected. RT real- time PCR and Western blot methods were used to detect mRNA expression and protein phosphorylation level changes of tau protein in PC12 cells of each group. Results： For mRNA expression of each group,there was no significant changes（ P 0. 05）.Compared with control group,phosphorylation levels of tau protein in Aβ group were significantly increased（ P 0. 05）while the phosphorylation level was decreased when the cells was treated with SSD. Conclusion： In PC12 cells,SSD may inhibit tau over- phosphorylation initiated by the treatment of Aβ25- 35.