Neurotoxicity of prion peptides on cultured cerebellar neurons.

Prion peptide (PrP) neurotoxicity has been modelled in vitro by using synthetic peptides derived from the PrP(C) sequence. The major region of neurotoxicity has been localized to the hydrophobic domain located in the middle of the PrP sequence. The neurotoxicity assays are typically performed on cultured mouse cerebellar neurons derived from neonatal pups, and viability can be monitored by a variety of assays, including MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium); MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) lactate dehydrogenase release; and apoptotic assays. These neurotoxicity studies have been useful in identifying cofactors, such as PrP(C) and metals as modulators of PrP peptide-mediated neurotoxicity. Given the biosafety issues associated with handling and purifying infectious prions, the use of synthetic peptides that display a dependence upon PrP(C) expression for toxicity, as per the PrP(Sc) agent for infectivity, supports the relevance of using these synthetic peptides for understanding PrP-mediated neurotoxicity.