细胞外钾离子对小鼠神经干细胞凋亡的影响

Effect of extracellular K^+ on the apoptosis of neural stem cells

目的探讨细胞外钾离子对体外培养神经干细胞增殖活性及凋亡的影响。方法无血清悬浮培养方法分离培养神经干细胞,取第3~5代培养细胞随机分为对照组,低、中、高浓度氯化钾组,利用MTT法检测不同浓度氯化钾对细胞活性的影响,通过Western Blot检测Caspase-3表达和原位末端标记(TUNEL)技术分析各组细胞凋亡上的差异。结果干预24 h后,各试验组细胞增殖活性均降低,且与对照组相比有统计学差异(P<0.01),高浓度氯化钾作用下TUNEL阳性细胞率为27.3%,显著高于对照组7.0%(P<0.01),而低浓度氯化钾和中等浓度氯化钾作用后TUNEL阳性细胞率分别为4.8%和5.4%,与对照组无显著升高(P>0.05),且高浓度氯化钾可以上调Caspase-3表达增加。结论提高细胞外钾离子可以抑制神经干细胞增殖,且高浓度钾离子可以诱导神经干细胞的凋亡。

Objective To explore the effect of K^＋ on the proliferation and apoptosis of neural stem cells （NSCs）. Methods The cells from the embryonic mouse brains were primarily cultured and identified. The cells were randomly divided into 4 groups： control group, Low- kcl group, Middle-kcl group and High-kcl group. The viability of NSCs was evaluated by MTT method. Apoptosis of NSCs was measured by TUNEL method and the expression of caspase-3 was detected by Western blot. Results Comparing to control group, after 24 h, the proliferation activity of all kcl groups were decreased significantly （P〈0.01）. And after 72 h, the percentages of TUNEL-positive cells in the High-kcl group （27. 3%） was increased significantly than control groups （7.0%, P〈0.01） , but the percentages of TUNEL-positive cells in the Low-kcl group （4. 8%）and Middle-kcl group （5.4%） had no significant change （P〉0.05） compared to control group. And the express of caspase-3 in the High-kcl group was upregulated. Conclusion The extracellular K^＋ suppress the proliferation of the NSCs and high concentration of K^＋ can induce apoptosis of NSCs.