PrPSc in N2a-FK cells undergoes degradation via upstream intracellular signalling cascades associated with autophagy.

(A) N2a-FK cells were treated with 0.1 to 10 μM of the the PI3K inhibitor LY294002 and 1 to 50 μM of the MEK inhibitor of PD98059 for 48 h. PK-treated or-untreated samples were applied at concentrations of 100 and 50 μg protein per lane onto a 15% polyacrylamide gel and subjected to SDS-PAGE. The proteins were analyzed by western blotting using anti-PrP, anti-Akt, anti-phosphorylated Akt (to determine the Akt activation level), anti-p44/p42 MAPK, anti-phosphorylated p44/p42 MAPK (to determine the p44/p42 MAPK activation level) and anti-β-actin antibodies. (B) The effect of these drugs on PrPSc was determined by quantifying the PrPSc band intensities as a percentage of those of the negative controls. The results in the graph are the mean ± SD of at least three independent experiments. *p < 0.05 and **p < 0.01 (one-way ANOVA followed by Tukey's test).