Ceruloplasmin Protects Against Rotenone-Induced Oxidative Stress and Neurotoxicity

To clarify the neuroprotective property of ceruloplasmin and the pathogenesis of aceruloplasminemia, we generated ceruloplasmin-deficient (CP ^−/−) mice on the C57BL/10 genetic background and further treated them with a mitochondrial complex I inhibitor, rotenone. There was no iron accumulation in the brains of CP ^−/− mice at least up to 60 weeks of age. Without rotenone treatment, CP ^−/− mice showed slight motor dysfunction compared with CP ^+/+ mice, but there were no detectable differences in the levels of oxidative stress markers between these two groups. A low dose of rotenone did not affect the mitochondrial complex I activity in our mice, however, it caused a significant change in motor behavior, neuropathology, or the levels of oxidative stress markers in CP ^−/− mice, but not in CP ^+/+ mice. Our data support that ceruloplasmin protects against rotenone-induced oxidative stress and neurotoxicity, probably through its antioxidant properties independently of its function of iron metabolism.