铜对低钾诱导大鼠小脑颗粒神经元凋亡的保护作用

Neuroprotective Effects of Copper against Apoptosis Induced by Low Potassium in Cultured Rat Cerebellar Granule Neurons

【目的】探讨铜体外抗低钾诱导大鼠小脑颗粒神经元(CGNs)凋亡作用及其机制。【方法】体外培养乳鼠的CGNs并用去极化诱导凋亡模型;噻唑兰(MTT)法检测细胞存活率;相差显微镜及Hoechst 33258染色分别观察细胞及其核形态学变化;流式细胞仪(FCM)检测亚二倍体峰。【结果】1～40μmol/L的铜可抗低钾所致的大鼠CGNs凋亡,明显提高CGNs的存活率。铜(20 μmol/L)显著减少低钾所致的大鼠CGNs胞体皱缩、细胞核固缩和亚二倍体峰等凋亡特征。铜的神经保护作用可以持续72h以上。磷脂酰肌醇3-激酶(PI3-K)抑制剂LY294002可阻断铜的保护作用。【结论】一定浓度范围的铜对低钾所致的大鼠CGNs凋亡有保护作用,PI3-K/Akt信号传导通路可能参与其保护作用。

[Objective]To investigate the effects and mechanism of copper on apoptosis of primary cultured cerebellar granule neurons induced by low potassium. [Methods ] Apoptosis was induced by low potassium in cultured rat cerebellar granule neurons. The neuronal viability was measured by MTT. Morphology of neurons and their nuclei were observed by phase-contrast microscopy and Hoechst 33258 staining, separately. The ratio of apoptotic cells was detected by flow cytometry （FCM）. [ Results ] Appropriate copper （1.-40 μmol/L） blocked apoptosis of primary cultured cerebeUar granule neurons induced by low potassium. The effects of diminished neuronal body, chromatin concentration and the ratio of apoptotic cells induced by low potassium were markedly weakened by copper. The neuroprotective effect of copper sustained for over 72 h. But the effect can be suppressed by LY294002, a specific inhibitor of P13-K. [Conclusion] Copper, at appropriate concentration, was found to protect against apoptosis induced by low potassium in primary cultured cerebellar granule neurons and P13-K/Akt signaling pathway might be involved in the copper-mediated anti-apoptotic effects.