Involvement of ERK1/2 and p38 MAPK in up-regulation of 14-3-3 protein induced by hydrogen peroxide preconditioning in PC12 cells  

H_2O_2预处理通过ERK1/2和p38 MAPK信号通路上调14-3-3蛋白在PC12细胞中的表达(英文)

作　　者：苏庆杰[1,2] 陈小武[2] 陈志斌[2] 孙圣刚[1] 

机构地区：[1]华中科技大学附属协和医院神经内科,武汉430022 [2]海南医学院附属医院神经内科

出　　处：《Neuroscience Bulletin》2008年第4期244-250,共7页神经科学通报（英文版）

基　　金：the National Natural Science Foundation of China (No. 30570627)

摘　　要：Objective To investigate the protective effects of hydrogen peroxide preconditioning （HPP） on the pheochromocytoma （PC12） cells treated with 1-methyl-4-phenylpyridinium （MPP^＋） and to explore the potential mechanisms. Methods The viability and apoptosis of PC 12 cells were determinded by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay and 4′,6′-diamidino-2-phenylindole （DAPI） staining, respectively. The expressions of 14-3-3 protein and phospholylated p38 mitogen-activated protein kinase （MAPK） were determined by Western blot. Enzyme-linked immunosorbent assay （ELISA） was used to measure the activity of extracellular signal-regulated protein kinase 1/2 （ERK1/2）. Results The cell viability decreased and the number of apoptotic cells increased dramatically in MPP^＋ group compared with that in Control group. HPP induced a significant increase in cell viability and a marked decrease in population of apoptotic cells of the MPP^＋- treated PC 12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK 1/2 and p38 MAPK activities. The 14-3-3 protein expression was positively correlated with the phosphorylation of ERK1/2. Furthermore, inhibition of the ERK1/2 with PD98059 abolished the 14-3-3 protein up-regulation in PC 12 cells induced by HPP. Conclusion HPP protects PC 12 cells against MPP＋ toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.目的探讨H2O2预处理对1-甲基-4-苯基吡啶离子(1-methyl-4- phenylpyridinium, MPP+)诱导PC12细胞毒性损伤的保护作用及其可能的机制。方法分别用3-(4,5-二甲基噻唑-2)–2,5-二苯基四氮唑嗅盐[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,MTT]和4,6-二氨基-2-苯基吲哚(4’,6’-diamidino-2-phenylindole,DAPI)染色技术检测PC12 细胞的活力及细胞凋亡核形态改变;Western blot检测PC12细胞中14-3-3蛋白、磷酸化p38 MAPK的水平。酶联免疫吸附实验(Enzyme-linked immunosorbent assay,ELISA)试剂盒检测ERK1/2磷酸化水平。结果 MPP+处理PC12细胞24 h使细胞活力显著下降(51.6%),DAPI染色显示(51.3±6.6)%的PC12细胞呈现核固缩等细胞凋亡形态改变;H2O2预处理能显著增加PC12细胞活力(83.4%),减少凋亡细胞数[(24.9±4.3)%],说明H2O2预处理能对抗MPP+ 毒性,对 PC12 细胞具有保护作用。Western blot 结果显示,H2O2 预处理在减少 PC12 细胞凋亡的同时伴随有14-3-3蛋白及磷酸化p38 MAPK表达上调;ELISA实验显示ERK1/2磷酸化水平显著增加。相关分析显示14-3-3蛋白表达的上调与ERK1/2磷酸化水平呈正相关(r = 0.923,P < 0.01),而且PD98059抑制ERK1/2磷酸化后,H2O2预处理诱导14-3-3蛋白表达上调的作用消失。结论 H2O2预处理能对抗MPP+对PC12细胞的毒性作用,这种保护作用与细胞内14-3-3蛋白表达上调有关;而14-3-3蛋白表达上调与ERK1/2和p38 MAPK信号通路的激活有关。

关 键 词：hydrogen peroxide preconditioning 14-3-3 protein ERK1/2 p38 mitogen-activated protein kinase PC12 cell 

分 类 号：Q42[生物学—神经生物学]