1 Department of Neurology, the Affiliated Union Hospital of Huazhong University of Science and Techology, Wuhan 430022, China 
2 Department of Neurology, the Affiliated Hospital of Hainan Medical College, Haikou 570102, China

Abstract 

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 PC12 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 PC12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK1/2 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 PC12 cells induced by HPP. 
Conclusion 
HPP protects PC12 cells against MPP+ toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.

Keywords

hydrogen peroxide preconditioning; 14-3-3 protein; ERK1/2; p38 mitogen-activated protein kinase; PC12 cell

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