Proteomic study on neurite responses to oxidative stress: Search for differentially expressed proteins in isolated neurites of N1E115 cells

Reactive oxygen species attack several living organs and induce cell death. Previously, we found axonal/dendrite degeneration before the induction of cell death in hydrogen peroxidetreated neuro blastoma: N1E115 cells and primary neurons. This phenomenon may be connected with membrane oxidation, microtubule desta bilization and disruption of intracellular calcium homeostasis. However, its detailed mechanisms are not fully understood. Here, we identified proteins after treatment with hydrogen peroxide using isolated neurites by liquid chromatographymatrixassisted laser desorption/ionizationtime of flight/time of flight analysis. Twentyone proteins were increased after treatment with hydro gen peroxide. Specifically, 5 proteins which were secretogranin1, heat shock protein family D member 1, Brain acid soluble protein 1, heat shock 70kDa protein 5 and superoxide dismutase 1, were identified of all experiments and increased in isolated neurites of hydrogen peroxidetreated cells compared to the controls. Further more, secretogranin1 and heat shock protein family D member 1 protein expressions were significantly increased in normal aged and Alzheimer’s transgenic mice brains. These results indicate that secretogranin1 and heat shock protein family D member 1 might contribute to reactive oxygen speciesinduced neurite degeneration. Both proteins have been related to neurodegenerative disorders, so their study may shed light on neurite dysfunction.