ERK1/2信号通路介导同型半胱氨酸对PC12细胞的损伤作用

ERK1/2 mediates homocysteine-induced damage in PC12 cells

目的观察同型半胱氨酸(Homocysteine,Hcy)对PC12细胞的损伤作用,探讨胞外信号调节蛋白激酶1/2(extracellular signal-regulated protein kinases1and2,ERK1/2)通路在其中的作用。方法台盼蓝拒染法和MTT比色法检测细胞存活率,相差倒置显微镜观察细胞形态,Hoechst33258染色荧光照相术检测细胞凋亡,罗丹明123染色荧光照相术和流式细胞术检测细胞线粒体膜电位(mitochondrial membrane potential,MMP),Western blot检测ERK1/2磷酸化的水平。结果Hcy(2.5～20mmol/L)作用24h后,可浓度依赖性地抑制PC12细胞的存活率;10mmol/L Hcy处理24h后,PC12细胞出现核固缩等典型的凋亡特征;Hcy能明显地降低PC12细胞的MMP;Hcy能诱导ERK1/2磷酸化,特异性的ERK1/2阻断剂U0126可显著抑制Hcy对PC12细胞的损伤作用。结论Hcy可引起PC12细胞损伤,此作用与其抑制MMP及诱导ERK1/2磷酸化有关。

Objective To investigate PC12 cell injury induced by Homocysteine （Hcy）, and explore the effect of extracellular signal-regulated protein kinases 1 and 2 （ERK1/2） on the injury. Methods Cell viability was detected by trypan blue dye exclusion assay and MTF assay; Cell apoptosis was observed by using Hoechst 33258 staining and photofluorography; Mitochondrial membrane potential （MMP） was determined by Rhodamine 123 （Rh123） staining followed by photofluorography and flow cytometry. Phosphorylation of ERK1/2 was measured by Western blot assay. Results At the concentrations from 2.5 to 20 mmol/L, Hcy dose-dependently inhibited cell viability in PC12 cells; Hcy at 10 mmol/L for 24 h induced PC12 cell apoptnsis and decreased MMP; Hcy up-regulated ERK1/2 phosphorylation. U0126, a specific blocker of ERK1/2 significantly inhibited cytotoxicity-induced Hcy. Conclusion Hcy may induce PC12 cell injury. This effect may be associated with the inhibition of MMP and the activation ERK1/2.