双歧杆菌脂磷壁酸延缓细胞衰老的作用机制

Effect and mechanism of lipoteichoic acid of Bifidobacterium on delaying cell aing

目的探讨双歧杆菌脂磷壁酸(Lipoteichoic acid,LTA)在延缓H2O2诱导细胞衰老中的作用。方法H2O2诱导WI-38细胞衰老,β-半乳糖苷酶细胞化学染色计算衰老细胞百分率变化,RT-PCR和Western印迹检测衰老细胞p21、细胞周期蛋白E(cyclin E)和周期蛋白依赖性蛋白激酶2(CDK2)表达水平的变化。结果双歧杆菌LTA处理后,β-半乳糖苷酶细胞化学染色阳性细胞百分率较衰老模型组降低(P<0.01)。与年轻对照组相比,衰老模型组细胞中p21的表达增高,cyclin E和CDK2表达降低,而双歧杆菌LTA能够逆转上述变化(P<0.01)。结论双歧杆菌能延缓H2O2诱导的细胞衰老,机制可能与改变p21,cyclin E和CDK2表达水平有关。

Objective To explore the effect of lipoteichoic acid （LTA） of Bifidobacterium on delaying cell aging induced by H2O2. Methods WI-38 cell aging was induced by H2O2.β-galactosidase （β-gal） cytochemistry staining was used to evaluate the percent of aging cell and the mRNA and protein levels of p21, cyclin E and CDK2 were detected by RT-PCR and Western blot. Results Treatment with LTA（5, 10 μg/ml）led to a significant increase in the proportion of β-gal-positive ceils （P 〈 0. 01 ） and markedly decreased the mRNA and protein levels of p21 and increased the mRNA and protein levels of cyclin E and CDK2 in WI-38 cells in aging model group （all P 〈0. 01 ）. Conclusions LTA of Bifidobacterium can delay cell aging induced by H2O2, whose mechanism may have relation with change the expressions of p21, cyclin E and CDK2.