Calcium-dependent serine-threonine phosphatase, calcineurin inactivation mediated by baicalein attenuates prion protein-mediated neuronal cell damage

Abstract

Background: Prion diseases are a group of unvaryingly fatal neurodegenerative disorders characterized by neuronal cell death. Calcineurin and autophagy mediate prion-induced neurodegeneration, suggesting that inhibition of calcineurin and autophagy could be a target for therapy. Baicalein has been reported to exert neuroprotective effects against calcium-dependent neuronal cell death. Results: In the present study, we investigated whether baicalein attenuates prion peptide-mediated neurotoxicity and reduces calcineurin. We found that baicalein treatment inhibits prion protein-induced apoptosis. Baicalein inhibited calcium up-regulation and protected the cells against prion peptide‑induced neuron cell death by calcineurin inactivation. Furthermore, baicalein increased p62 protein levels and decrease LC3-II protein levels indicating autophagic flux inhibition and baicalein inhibited prion protein-induced neurotoxicity through autophagy flux inhibition. Conclusions: Taken together, this study demonstrated that baicalein attenuated prion peptide-induced neurotoxicity via calcineurin inactivation and autophagic flux reduction, and also suggest that baicalein may be an effective therapeutic drug against neurodegenerative diseases, including prion diseases.