Enhanced vulnerability to oxidative stress by α-synuclein mutations and C-terminal truncation

• Published in: Neuroscience 2000-01, Vol.97 (2), p.279-284
• Main Authors: Kanda, S, Bishop, J.F, Eglitis, M.A, Yang, Y, Mouradian, M.M
• Format: Article
• Language: English
• Subjects: 1-Methyl-4-phenylpyridinium - toxicity; alpha-Synuclein; Amino Acid Substitution; Brain - metabolism; cell death; Cell Survival - drug effects; Humans; Hydrogen Peroxide - pharmacology; Mutagenesis, Site-Directed; Nerve Tissue Proteins - chemistry; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - physiology; Neuroblastoma; neuron; oxidative stress; Oxidative Stress - drug effects; Parkinson’s disease; Phosphoproteins - physiology; Recombinant Proteins - chemistry; Recombinant Proteins - metabolism; Sequence Deletion; Synucleins; Transfection; Tumor Cells, Cultured; α-synuclein
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/S0306-4522(00)00077-4

α-Synuclein is a key component of Lewy bodies found in the brains of patients with Parkinson’s disease and two point mutations in this protein, Ala53Thr and Ala30Pro, are associated with rare familial forms of the disease. Several lines of evidence suggest the involvement of oxidative stress in the pathogenesis of nigral neuronal death in Parkinson’s disease. In the present work we studied the effects of changes in the α-synuclein sequence on the susceptibility of cells to reactive oxygen species. Human dopaminergic neuroblastoma SH-SY5Y cells were stably transduced with various isoforms of α-synuclein and their survival following exposure to hydrogen peroxide or to the dopaminergic neurotoxin MPP + was assessed. Cells expressing the two point mutant isoforms of α-synuclein were significantly more vulnerable to oxidative stress, with the Ala53Thr engineered cells faring the worst. In addition, cells expressing C-terminally truncated α-synuclein, particularly the 1–120 residue protein, were more susceptible than control β-galactosidase engineered cells. The present experiments indicate that point mutations and C-terminal truncation of α-synuclein exaggerate the susceptibility of dopaminergic cells to oxidative damage. Thus, these observations provide a pathogenetic link between α-synuclein aberrations and a putative cell death mechanism in Parkinson’s disease.