Abstract: Objective To investigate the effects of oxidative stress and serum of patient with Parkinson's disease(PD) on the mitochondrial and nuclear translocation of alpha-synuclein(α-Syn).Methods MES 23.5 dopaminergic neuronal cells were cultured in DMEM/F12 medium containing 5% fetal bovine serum.The cells were treated with H₂O₂ and sera from PD patients and the mitochondrial and nuclear translocations of α-syn were examined using immunofluorescent labeling.The serumal oxidative stress was evaluated by measuring with colorimetry the levels of superoxide dismutase(SOD),malondialdehyde(MDA),and total anti-oxidation competence(T-AOC) in the serum.Results Both the H₂O₂ and PD serum promoted the mitochondrial and nuclear translocations of α-syn,with shrank and disrupted mitochondria observed in the treated cells.The PD serum-treated cells also displayed apoptosis-like disintegrated nuclei.The levels of SOD,MDA and T-AOC were higher in PD sera than in normal sera.Conclusion Oxidative stress and PD serum promote mitochondrial and nuclear translocations of α-syn.The effect of PD serum is probably related to the increased oxidative stress.

Key words: α-synuclein, Parkinson's disease, serum, mitochondria, nucleus