Oxidative Stress Induced by the Deubiquitinase Inhibitor b-AP15 Is Associated with Mitochondrial Impairment

Figure 2

Evidence of oxidative stress in b-AP15-exposed HCT116 cells. (a) HCT116 cells were exposed to 0.5% DMSO or b-AP15 (0.25, 0.5, and 1.0 μM in 0.5% DMSO) for 6 h, and extracts were prepared and subjected to immunoblotting using the indicated antibodies. (b) Increases in the ratio of GSSG/GSH in HCT116 cells exposed to 1 μM b-AP15 for the indicated times (; , ; ). (c) Total levels of GSH were determined in vehicle-treated cells and in cells exposed to 1 μM b-AP15 for 6 h (; ; N.S.: not significant at ). (d) Glucose-6-phosphate dehydrogenase activity in HCT116 cells exposed to 1 μM b-AP15 for 6 h compared to vehicle-treated cells (; ; ). (e) Glutathione peroxidase activity in HCT116 cells exposed to 1 μM b-AP15 for 6 h compared to vehicle-treated cells (; ). (f) Malondialdehyde levels in HCT116 cells exposed to 1 μM b-AP15 or vehicle for 6 h. Statistical significance was calculated using Student’s -test in (b)–(f).

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