Neuroprotective mechanism of mitochondrial ferritin on 6-hydroxydopamine-induced dopaminergic cell damage: implication for neuroprotection in Parkinson's disease.

Neuronal iron homeostasis disruption and oxidative stress are closely related to the pathogenesis of Parkinson's disease (PD). Adult iron-regulatory protein 2 knockout (Ireb2(-/-)) mice develop iron accumulation in white matter tracts and nuclei in different brain area and display severe neurodegeneration in Purkinje cells of the cerebrum. Mitochondrial ferritin (MtFt), a newly discovered ferritin, specifically expresses in high energy-consuming cells, including neurons of brain and spinal cord. Interestingly, the decreased expression of MtFt in cerebrum, but not in striatum, matches the differential neurodegeneration pattern in these Ireb2(-/-) mice. To explore its effect on neurodegeneration, the effects of MtFt expression on 6-hydrodopamine (6-OHDA)-induced neuronal damage was examined. The overexpression of MtFt led to a cytosolic iron deficiency in the neuronal cells and significantly prevented the alteration of iron redistribution induced by 6-OHDA. Importantly, MtFt strongly inhibited mitochondrial damage, decreased production of the reactive oxygen species and lipid peroxidation, and dramatically rescued apoptosis by regulating Bcl-2, Bax and caspase-3 pathways. In conclusion, this study demonstrates that MtFt plays an important role in preventing neuronal damage in an 6-OHDA-induced parkinsonian phenotype by maintaining iron homeostasis. Regulation of MtFt expression in neuronal cells may provide a new neuroprotective strategy for PD.