摘要
目的研究1-甲基-4-苯基吡啶离子(MPP+)重新启动多巴胺能神经元细胞周期的作用及机制。方法使用MPP+处理神经元样分化的PC12细胞,采用四甲基偶氮唑盐(MTT)法检测细胞活力,流式细胞仪检测早期凋亡细胞和细胞周期分布,免疫细胞化学检测ERK/MAPK通路活化水平。结果经MPP+处理后,细胞活力呈浓度依赖性下降,经25、50、75、100、150 mmol/L MPP+处理24 h后细胞存活率分别下降至对照组的(97.32±2.41)%(、67.69±3.03)%、(56.00±3.12)%、(47.23±2.55)%、(40.00±2.46)%,与对照组相比差异均有统计学意义(P<0.01)。经75 mmol/L MPP+处理后出现早期凋亡细胞,随处理时间延长,细胞凋亡率逐渐增加,其处理4、8、16和24 h后细胞凋亡率分别为(7.26±3.43)%、(8.34±3.55)%(、20.04±2.64)%和(28.46±2.35)%(P<0.01)。同时细胞周期中G0/G1期细胞减少,S期和G2/M期细胞增多(P<0.01),细胞内ERK1/2通路活化。结论MPP+可通过活化ERK1/2通路重新启动多巴胺神经元的细胞周期,并诱导多巴胺能神经元凋亡。
Objective To investigate the effect and mechanism of dopaminergic cell cycle reentry induced by MPP^＋. Methods PC12 cells as dopaminergic neurons, differentiated by nerve growth factor, were treated by MPP^＋. Cell viability was measured by MTT, flow cytometry was used to detect cell apoptosis and the changes of cell cycle, and immunocytochemistry was used to study the activation state of ERK1/2 pathway. Results After treated with MPP^＋ the cell viability declined in a concentration-dependent manner. Compared with the control group, exposing to 25, 50, 75, 100 and 150 mmol/L MPP^＋ for 24 h caused cell viability decline to （7.32± 2.41） %, （7.69± 3.03） %, （ 56.00± 3.12） %, （ 47.23± 2. 55） % and （40. 00 ± 2. 46） % （P〈0.01） respectively. The early sign of apoptosis was found with flow cytometry, and the apoptosis ratio increased in a time-dependent manner. The apoptosis ratios induced by 75 mmol/L MPP^＋ for 4, 8, 16 and 24 h were（7. 26±3. 43）%, （8. 34± 3.55）% ,（ 20. 04±2. 64）% and（ 28. 46±2. 35）%（P〈0. 01）respectively. The percentage of cells in the G0/G1 phase decreased and that in the G2/M phase increased（P〈0. 01）. This was associated with a rapid activation of phosphorylated ERK1/2. Conclusious MPP^＋ might induce cell apoptosis of dopaminergic neuron by activation of ERK1/2 pathway and the subsequently reentry of cell cycle.
出处
《中国神经免疫学和神经病学杂志》
CAS
2006年第4期215-219,共5页
Chinese Journal of Neuroimmunology and Neurology
基金
国家自然科学基金资助项目(30570627)
