Catalytic subunit of NADPH oxidase Nox2 is elevated by the MPP+ treatment. N27 cells were treated with different concentrations of MPP+ for 24 hours. (A) Survival of N27 cells as a function of MPP+ concentration. (B) Immunofluorescent detection of Nox2 in N27 cells cultured either in the absence (control, ctrl) or presence of 300 μM MPP+, a concentration of MPP+ that results in loss of 45 percent of N27 cells. Scale bar equals to 20 μm. (C) Western immunoblot illustrating the effect of treating the cultures with increasing concentrations of MPP+ on expression of Nox2 protein. β-actin served as a loading control. Data in panel A, are from 3 independent experiments with n = 6 wells per experiment and *represents p < 0.01 compared to all other concentrations examined.