JNK信号转导通路在β-淀粉样蛋白_(25-35)诱导PC12细胞凋亡中的作用机制

Study on the roles of JNK-c-Jun signal transduction pathway in Aβ_(25-35) -induced PC12 cells apoptosis

目的 研究β淀粉样蛋白25 35(Aβ25 35)诱导大鼠嗜铬细胞瘤(PC12)细胞凋亡的机制以及c Jun氨基端激酶(JNK)抑制剂SP600125的保护作用,探讨在Aβ25 35 细胞毒性中JNK c Jun信号转导通路的可能作用机制。 方法 在培养的PC12 细胞中加入Aβ25 35 共孵育,用磷脂酰丝氨酸外翻分析(Annexin V)方法和流式细胞仪检测PC12细胞的凋亡,用免疫印迹法检测不同时间点的JNK及c Jun蛋白活性。 结果 PC12细胞经过Aβ25 35处理后发生凋亡,呈时间依赖性细胞生存率下降,免疫学方法检测显示细胞在Aβ25 35处理早期出现磷酸化JNK和磷酸化c Jun的表达增高,且这一过程可被SP600125抑制。流式细胞仪检测显示在使用SP600125 后,细胞生存率上升,差异具有统计学意义。 结论 体外PC12细胞培养显示Aβ25 35 可诱导细胞凋亡,SP600125 对Aβ25 35 的细胞毒性具有保护作用,JNK c Jun信号转导通路可能参与了上述细胞毒作用机制。

Objective To investigate the mechanism of β-amyloid(Aβ)25-35 -induced PC12 cells death and the protection of SP600125(a JNK inhibitor) and to determine a possible mechanism of JNK c Jun signal transduction pathway involved in the Aβ 25 35 induced PC12 cell death. Methods The PC12 cells were incubated with Aβ 25 35 , then underwent Annexin V fluorescence staining and flow cytometry detection. The expression of p JNK and p c Jun was measured by Western blot analysis. Results After the incubation with Aβ 25 35 , the cells were induced to be apoptosis. The viability of PC12 cells was decreased in a time dependent manner. At the early stage following the exposure to Aβ 25 35 , the elevated expression of p JNK and p c Jun was detected by means of immunological methods. The increased expression of p JNK and p c Jun could be inhibited by SP600125. Flow cytometry showed that SP600125 demonstrated a significantly protective effect on the Aβ 25 35 evoked apoptosis and a reduced cell viability in PC12 cells. Conclusions The present study indicates that Aβ 25 35 can induce the apoptosis in PC12 cells, which can be inhibited by SP600125. JNK c Jun signal transduction pathway may play an important role in the Aβ (25-35) -induced PC12 cell apoptosis.