Figure 5.

α-Syn siRNA pool suppresses VPA-induced increase of α-syn protein, blocks VPA-induced protection, and facilitates glutamate excitotoxicity. Cells were exposed to α-syn siRNA pool (100 nm) or scrambled siRNA (100 nm) for 24 h before pretreatment with 0.4 mm VPA for 6 d (DIV 1 to DIV 7). Cells were either harvested for Western blot (A) or subsequently treated with glutamate (Glut; 100 μm) for 24 h (B). Cells were also exposed to α-syn siRNA pool or its scrambled siRNA control for 6 d (DIV 1 to DIV 7) and then exposed to the indicated concentration of glutamate for 24 h (C). Cell viability was quantified by MTT assay and expressed as means ± SEM of vehicle-treated control from three independent cultures. ∗∗∗p < 0.001 compared with vehicle-treated control.