Aβ_(25-35)诱导PC12细胞周期紊乱及对P53和Cyclin D1基因表达的影响  

Effects of Aβ_(25-35)on Serum-deprived PC12 Cell Cycle and Expression of P53 and Cyclin D1

作　　者：谢朝阳[1] 梅寒芳[1] 祝其锋[1] 

机构地区：[1]广东医学院生物化学与分子生物学研究所

出　　处：《武汉大学学报（医学版）》2007年第1期31-35,43,共6页Medical Journal of Wuhan University

基　　金：广东省重点学科资助项目(编号:9808);广东省湛江市科技计划项目(编号:2004003)

摘　　要：目的:探讨Aβ25-35诱导体外去血清培养的PC12细胞周期变化及对P53和Cyclin D1基因表达的影响。方法:PC12细胞同步于G0期,采用终浓度为0-45μmol/L或浓度为25μmol/L Aβ25-35处理PC12细胞,用MTT比色法分析细胞存活率;流式细胞仪检测分析细胞周期的改变;RT-PCR和Western blot从mRNA及蛋白水平检测P53和Cyclin D1基因的变化。结果:随着Aβ25-35剂量的增加,PC12细胞存活率降低(P<0.01);流式细胞仪分析表明去血清培养24 h可使约90%PC12细胞停滞于G0/G1期,25μmol/L Aβ25-35诱导组8,16,24 h与对照组比较,S期百分率明显增加(P<0.01),16 h后细胞凋亡率明显增加(P<0.01),可见明显的亚二倍体峰(Ap峰);P53 mR-NA表达和P53蛋白表达降低、Cyclin D1 mRNA表达和Cyclin D1蛋白表达增高。结论:Aβ25-35降低去血清培养的PC12细胞存活率,诱导同步化于G0/G1的PC12细胞重新进入细胞周期,并阻滞于S期,同时出现凋亡,可能与下调P53的表达,上调Cyclin D1的表达有关。Objective： To study the effect on cell cycle and the expression of P53, Cyclin D1 of serumdeprived PC12 cells induced by Aβ25-35. Methods： PC12 cells were synchronized by 24 hours serum deprivation and were treated with different concentration of Aβ25-35 （0-45 μmol/L） for different time. The cell survival rate was evaluated by MTT assay. Cell cycle distribution was analyzed by flow cytometry （FCM）. Protein and mRNA expression of P53 and Cyclin D1 were detected by RT-PCR and Western-blot respectively. Results： Aβ25-35 decreased the survival rate of PC12 cells in a dose-dependent manner. About 90% PC12 cells were found arrest on G0/G1 by FCM after deprived of serum for 24 hours. Treated with 25 μmol/L Aβ25-35 for 8,16 and 24 hours,the percent of S phase cells was raised remarkably （P〈0. 01） at 8 h, and the percent of S phase cells was declined gradually after 16 hours. Meanwhile the apoptotic rate was detected being increased obviously between 16 h and 24 h （P〈0. 01） and the obvious hypodiploid peak ahead of G0/G1 phase （Ap） was shown. Aβ25-35 decreased the expression of P53 mRNA and protein, and increased the expression of Cyclin D1 mRNA and protein. Conclusion： Aβ25-35 decreases survival rate of synchronized PC12 cells and induces the apoptosis in a dose-dependent manner. Aβ25-35 induced synchronized PC12 cells attempts to reenter cell cycle,and is arrested on S phase showing apoptotic peak subsequently. This is likely related to decreasing the P53 expression and increasing the Cyclin D expression.

关 键 词：AΒ25-35 PC12细胞 细胞周期 P53 CYCLIN D1 

分 类 号：R332.85[医药卫生—人体生理学]