β-淀粉样肽25-35诱导PC12细胞周期紊乱及其可能机制的研究

Possible mechanisim of β-Amyloid peptide 25-35-induced abnormal cell cycle in PC 12 cells

目的探讨β-淀粉样肽25-35(Aβ25-35)对PC12细胞周期及其相关基因表达的影响。方法 25μmol/LAβ25-35处理PC12细胞,用流式细胞术观察细胞周期变化,电泳观察凋亡条带,RT-PCR和Westernblot检测p21、CyclinD1、E2F1、pRb表达。结果 Aβ25-35处理后8h,PC12细胞S期明显增加(P<0.01),但16、24h逐渐降低(P<0.01);16h后细胞凋亡明显增加(P<0.01)。Aβ25-35处理4h后,p21mRNA和蛋白表达降低;CyclinD1、E2F1mRNA和CyclinD1、pRb蛋白表达增高(P<0.05)。结论 Aβ25-35诱导同步化的PC12细胞周期紊乱及凋亡,可能与下调p21表达和上调CyclinD1、pRb和E2F1表达有关。

Objective To study the effect of Aβ25-35 on PC12 cell cycle and expression of cell cycle related genes. Methods After treated with 25 μmol/L Aβ25-35, cell cycle, apoptosis, and expression of p21, Cyclin D1, pRb and E2F1 were detected by flow cytometry, electrophoresis, RT-PCR and Western-blot in PC12 cells, respectively. Results Percentage of S phase cells increased remarkably at 8 h, but decreased at 16 h and 24 h after Aβ25-35 treatment （P〈0.01）. Cell apoptosis elevated obviously after 16 h （P〈0.01）. Expression of p21 decreased, but that of Cyclin D1, pRb and E2F1 increased after 4 h of Aβ25-35 treatment. Conclusion Aβ25-35 can induce the abnormal cycle and apoptosis of synchronized PC12 cells, which is likely related to downexpression of p21 and overexpression of Cyclin D1, pRb and E2F1.