神经酰胺通过JNK/c-Jun信号通路诱导胶质瘤细胞自噬性死亡

摘要

Objective To observe the autophagy of 87-MG and U251 glioma cells induced by ceramide and explore the possible mecha-nism. Methods The viability and apoptosis of 87-MG and U251 cells were detected by MTT assay and flow cytometry, respectively. Autoph-agic-related protein expressions of LC3B/LC3A and Beclin-1 were determined by Western blotting. The activation of JNK/c-Jun signaling pathway induced by ceramide with or without the treatment of JNK specific inhibitor SP600125 was also measured. Results 24 hours after treatment of ceramide, the growth of 87-MG and U251 cells was significantly inhibited time-dependently (P<0.05);and the number of au-tophagic cells increased dose-dependently (P<0.05). The levels of LC3B/LC3A and Beclin-1 significantly increased after ceramide treat-ment (P<0.05). JNK signaling pathway was activated in the 87-MG and U251 cells and the phosphorylation of c-Jun also increased after ce-ramide treatment. This activation of autophagy could be reversed by the pre-treatment of SP600125. Conclusion Ceramide may induce au-tophagy in 87-MG and U251 glioma cells and the mechanism may be related to the activation of JNK/c-Jun signaling pathway.%目的：探讨神经酰胺对胶质瘤细胞87-MG和U251自噬性死亡的作用及机制。方法采用MTT和流式细胞的方法检测不同浓度神经酰胺刺激87-MG和U251细胞后细胞存活和凋亡的改变；电镜和Western blotting技术检测自噬和JNK/c-Jun信号通路的改变，JNK药理性抑制剂SP600125特异性抑制JNK通路，观察其对神经酰胺诱导自噬死亡的影响。结果神经酰胺刺激24 h后，87-MG和U251存活呈现时间依赖性下降(P<0.05)；相应的细胞死亡数目剂量依赖性升高(P<0.05)，但凋亡性死亡比例较低；神经酰胺刺激后镜下观察到的自噬小体计数，LC3B/LC3A和Beclin-1的表达以及JNK/c-Jun的磷酸化程度都增加(P<0.05)。提前给予SP600125抑制JNK信号通路的活性后，可以阻断神经酰胺诱导的细胞自噬性死亡(P<0.05)。结论神经酰胺可诱导胶质瘤细胞87-MG和U251出现自噬性死亡，机制可能与JNK信号通路的活化有关。