Metabolomic analysis revealed mitochondrial dysfunction and aberrant choline metabolism in MPP⁺-exposed SH-SY5Y cells

1-Methyl-4-phenylpyridinium (MPP⁺)-treated human neuroblastoma SH-SY5Y cells have been generally accepted as a cellular model for Parkinson's disease. To understand comprehensive metabolic disturbances in this model, both cell lysates and culture supernatants were subjected to metabolomic analysis. As expected from the fact that MPP⁺ inhibits mitochondrial complex I, a metabolic shift from mitochondrial oxidative phosphorylation to glycolysis was indicated by an increase in extracellular lactic acid and a parallel depletion of pyruvic acid. In cell lysates, the metabolic shift was supported by consistent decreases in TCA cycle intermediates. Metabolomic analysis also revealed aberrant choline metabolism. Choline in the culture supernatant was elevated 8.5- and 17-fold by 30 and 300 μM MPP⁺ exposure, respectively; therefore, extracellular choline might be a metabolic biomarker for Parkinson's disease.