Okadaic acid-induced upregulation of nitrotyrosine and heme oxygenase-1 inrat cortical neuron cultures

Hyperphosphorylation of tau is a characteristic feature of the neurodegener ative pathology in Alzheimer's disease (AD). Okadaic acid (OA) is currently used in models of AD research to increase the phosphorylation of tau. Usin g immunocytochemistry and fluorescent study, we found that markers of oxida tive activity such as nitrotyrosine, c-jun, 2',7'-dichlorofluorescein diace tate (DCF), and heme oxygenase-1 (HO-1) were altered in OA-treated culture. Immunoreactivity of nitrotyrosine and c-jun, and DCF-oxidation were increa sed in degenerating neurons, while HO-1 expression was increased in astrocy te in response to OA. The data suggest that tau phosphorylation and oxidati ve damage be implicated in OA-induced neurodegeneration. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.