磷酸化蛋白酪氨酸激酶及信号转导子和转录激活子在谷氨酸诱导的PC12细胞凋亡中的表达研究

Expressions of phosphorylated JAK2 and STAT3 in PC12 cells after glutamate-induced apoptosis

目的探讨谷氨酸诱导PC12细胞凋亡后磷酸化蛋白酪氨酸激酶2(P-JAK2)、磷酸化信号转导子与转录激活子3(P-STAT3)表达的变化及意义。方法采用谷氨酸诱导PC12细胞发生凋亡,实验分为6组,分别为正常对照组、500μmol/L谷氨酸作用5、10、20、30、60 min组,应用流式细胞仪观察PC12细胞凋亡,Western blot定量观测PC12细胞P-JAK2与P-STAT3蛋白表达的变化。结果对照组PC12细胞的凋亡率为(2.71±0.32)%;经500μmol/L谷氨酸作用PC12细胞20 min,凋亡率增加到(61.20±4.60)%,与对照组相比差异有显著性意义(P=-0.000);Western blot检测结果表明P-JAK2 5 min在胞浆中开始表达,20 min达最高峰,是5 min组(3.52±0.20)倍(P= 0.002);P-STAT3 5 min表达增强,30 min达高峰,为5 min组的(4.76±0.17)倍(P=0.000)。结论细胞损伤激活了JAK/STAT信号转导通路,该通路参与了神经细胞凋亡的过程。

Objective To study the change and significance of the expressions of phosphorylated Janus kinase 2 （P-JAK2） and phosphorylated signal transducer and activator of transcription 3 （P-STAT3） in PC12 cells after glutamate-induced apoptosis. Methods PC12 cells were assigned to normal control group and apoptosis groups. The apoptosis was induced by glutamic acid （500 μmol/L） for 5, 10, 20, 30 and 60 min, and observed with flow cytometry. The change of P-JAK2 and P-STAT3 protein expressions in PC 12 cells was detected with Western blot in each group. Results Compared with control group [（2.71±0.32）%], the apoptosis rate of 20 min apoptosis group [（61.20±4.60）%] was increased significantly （P=0.000）; Western blot analysis revealed the expression of P-JAK2 began to rise at 5 min of apoptosis induction and peaked at 20 min, and the maximum was （3.52± 0.20） times as high as the level at 5 min （P=0.002）; the expression of P-STAT3 enhanced in cytoplasm at 5 min and reached the peak at 30 min, and the quantity was （4.76±0.17） times as high as 5 min apoptosis group （P=0.000）. Conclusion Cell injury can activate JAK2/STAT3 signal pathway, which indicates that JAK2/STAT3 signal pathway play an important role in the procedure of nerve cell apoptosis.