Imbalance of brain metal homeostasis and associated oxidative stress by redox-active metals like iron and copper is an important trigger of neurotoxicity in several neurodegenerative conditions, including prion disorders. While some reports attribute this to end-stage disease, others provide evidence for specific mechanisms leading to brain metal dyshomeostasis during disease progression. In prion disorders, imbalance of brain iron homeostasis is observed before end stage disease and worsens with disease progression, implicating iron-induced oxidative stress in disease pathogenesis. This is an unexpected observation since the underlying cause of brain pathology in all prion disorders is PrP-scrapie (PrPSc), a -sheet rich conformation of a normal glycoprotein, the prion protein (PrPC). Whether brain iron dyshomeostasis occurs due to gain of toxic function by PrPSc or loss of normal function of PrPC remains unclear. In this review, we summarize available evidence suggesting the involvement of oxidative stress in prion disease pathogenesis. Subsequently, we review the biology of PrPC to highlight its possible role in maintaining brain metal homeostasis during health, and the contribution of PrPSc in inducing brain metal imbalance with disease progression. Finally, we discuss possible therapeutic avenues directed at restoring brain metal homeostasis and alleviating metal-induced oxidative stress in prion disorders.
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