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.