p38 MAP kinase mediates the cell death induced by PrP106-126 in the SH-SY5Y neuroblastoma cells.

Prion diseases are neurodegenerative pathologies characterized by the accumulation in the brain of a protease-resistant form of the prion protein (PrP(c)), named PrP(Sc). A synthetic peptide homologous to residues 106-126 of PrP (PrP106-126) maintains many PrP(Sc) characteristics. We investigated the intracellular signaling responsible for the PrP106-126-dependent cell death of SH-SY5Y, a cell line derived from a human neuroblastoma. In this cell line, PrP106-126 induced apoptotic cell death and caused activation of caspase-3, although the blockade of this enzyme did not inhibit cell death. The p38 MAP kinase blockers, SB203580 and PD169316, prevented the apoptotic cell death evoked by PrP106-126 and Western blot analysis revealed that the exposure of the cells to the peptide induced p38 phosphorylation. Taken together, our data suggest that the p38 MAP kinase pathway can mediate the SH-SY5Y cell death induced by PrP106-126.