[Relation between beta-amyloid peptide-25-35 inducing cell cycle change and apoptosis of serum-deprived PC12 cell]
Zhao-yang Xie1, Han-fang Mei, Qi-feng Zhu
1Institute of Biochemistry and Molecular Biology, Guangdong Medical College, Zhanjiang 524023, China.
Objective:
To study the relation between cell cycle change and apoptosis of serum-deprived PC12 cell, which are induced by beta-amyloid peptide-25-35 (alpha beta(25-35)).
Methods:
PC12 cells were synchronized by cultured in deprivation of serum for 24 h and treated with different concentration of alpha beta(25-35) (0-45 micromol/L) for another 24 h,and the cell survival rate was evaluated by MTT assay. The cell apoptosis was analyzed by Hoechst fluorescence staining and DNA agarose gel electrophoresis. The relation between cell cycle redistribution and apoptosis was analyzed by flow cytometry (FCM).
Results:
alpha beta(25-35) decreased the survival rate of PC12 cells in dose-dependent manner. The typical apoptotic cells were showed by fluorescence staining when treated with 25 micromol/L alpha beta(25-35) for 24 h;the obvious DNA-Ladder was showed by DNA agarose electrophoresis. About 90% PC12 cells were found to arrest on G0/G1 by FCM being deprived serum. Treated with 25 micromol/L alpha beta(25-35) for 8, 16, 24 h, the percent of S phase cells was raised remarkably (P < 0.01) at 8 h, but the percent of S phase cells was declined gradually after treated for 16 h. Meanwhile the apoptotic rate was detected being increased obviously between 16 h and 24 h (P < 0.01), the obvious hypodiploid peak could be observed ahead of G0/G1 phase(Ap).
Conclusion:
alpha beta(25-35) decreases the survival rate of synchronized PC12 cell and induces the synchronized PC12 cells attempting to reenter cell cycle,which appear the apoptotic peak subsequently. This indicates that the cell apoptosis may be related to the abnormal cell cycle distribution induced by alpha beta(25-35), which means there may be a close relationship between cell cycle and apoptosis.
