Reactive oxygen species regulate alpha-synuclein phosphorylation state in human differentiated neuroblastoma cells

Reactive oxygen species (ROS) are known to occur as natural by-products under physiological condition and have been implicated in the neuronal alterations observed in a variety of age-related neurophatological conditions. Biomarkers of production of reactive oxygen/nitrogen species have been seen to be associated with phospho-alpha-synuclein-immunopositive lesions detected in different neurodegenerative diseases known as synucleopathies. The phospho-serine 129 alpha-synuclein promotes fibril formation in vitro, suggesting the importance of phosphorylation of the filamentous protein in the pathogenesis of these diseases. In the present study, we have analyzed the regulation of alpha-synuclein phosphorylation state following increased levels of ROS induced by pro-oxidant agents in viable human differentiated neuroblastoma cells. We report that alpha-synuclein is constitutively expressed and phosphorylated in serine 87 and 129 in SH-SY5Y differentiated cells as detected by Western blot analysis using specific phospho-antibodies. In addition we found that the phosphorylation state of alpha-synuclein is regulated by high levels of intracellular ROS. These results demonstrated that supraphysiological levels of ROS induced post-translation modification of the alpha-synuclein protein supporting the notion of the role of oxidative stress in neurodegenerative disease characterized by alpha-synuclein positive lesions. Supported by the University of Bologna, Funds for Selected Research Topics.