二苯乙烯苷对冈田酸诱导的NG108-15细胞tau蛋白磷酸化的干预作用

Intervention effect of tetrahydroxy stilbene glycoside on tau protein phosphorylation in NG108-15 cells induced by Okadaic acid

目的观察二苯乙烯苷(TSG)对冈田酸诱导的NG108-15细胞增殖及磷酸激酶PP2A、PP2B、PP5和tau蛋白磷酸化的影响,探讨其抗老年痴呆的作用机制。方法采用MTT法观察TSG作用于冈田酸诱导的NG108-15细胞24h的增殖情况。取对数生长期的NG108-15细胞,将其分为正常组,模型组,以及TSG低、中、高剂量(50nmol·L^(-1)、100nmol·L^(-1)、200nmol·L^(-1))组。利用AO/EB双荧光染色法检测TSG对细胞凋亡的影响;蛋白质免疫印迹法(Western Immunoblotting)检测PP2A、PP2B、PP5、tau和P-tau的表达。qRT-PCR法检测PP2A、PP2BmRNA的变化。免疫荧光(immunofluorescence)检测PP2A、PP2B和tau蛋白表达和分布。结果 TSG能够增强冈田酸诱导的NG108-15细胞的增殖能力,呈一定的剂量依赖;与模型组比较,TSG能抑制冈田酸对NG108-15细胞的衰老。TSG能提高PP2A、PP2B、PP5蛋白和降低P-tau蛋白的表达;此外,还能提高PP2A、PP2BmRNA的转录水平。结论二苯乙烯苷能提高NG108-15细胞的抗衰老能力,降低tau蛋白的异常磷酸化,其机制可能是与参与下调tau蛋白磷酸化的磷酸酶有关。

Objective To observe the effect of tetrahydroxy stilbene glycosidec (TSG) on proliferation of NG108-15 cells induced by Okadaic acid and phosphokinase PP2A,PP2B,PP5 and phosphorylation of tau protein,and explore the mechanism of its anti-Alzheimer’s disease.Methods MTT assay was used to observe the effects of TSG on proliferation of NG108-15 cells induced by Okadaic acid at 24 h.NG108-15 cells at logarithmic growth stage were taken and divided into normal a group,a model group,and TSG low-,medium- and high-dose (50 nmol·L^-1 、100 nmol·L^-1 、200 nmol·L^-1 ) groups.The effect of TSG on cell apoptosis was detected by AO/EB double fluorescence staining.The expressions of protein phosphatase 2A(PP2A),protein phosphatase 2B(PP2B),protein phosphatase 5(PP5),tau and P-tau were detected by western Immunoblotting.The changes of mRNA of PP2A and PP2B were measured by qRT-PCR.The expression and distribution of PP2A,PP2B and tau protein were detected by immunofluorescence.Results TSG could enhance the proliferation of NG108-15 cells induced by Okadaic acid in a dose-dependent manner.Compared with the model group,TSG could inhibit the senescence of NG108-15 cells induced by Okadaic acid.TSG could increase the expression of PP2A,PP2B and PP5 protein and reduce the expression of P-tau protein.In addition,TSG could also increase the transcription of PP2A,PP2B mRNA.Conclusion TSG can improve the anti-aging ability of NG108-15 cells and reduce the abnormal phosphorylation of tau protein,and the mechanism may be related to phosphatases involved in the down-regulation of tau protein phosphorylation.