Increased expression of Bcl-XL in NPCs by VPA. (A) Bcl-XL expression was measured by Western blot after VPA treatment. VPA significantly increased Bcl-XL expression in a concentration dependent manner. Levels of β-actin were used as control, which was not different among groups. (B) Densitometric quantification of Bcl-XL expressions (n = 5). (C) Immunocytochemical staining of Bcl-XL expression in NPCs. Left, NPCs were stained with Bcl-XL. Middle, NPCs were stained with nestin, a marker of NPCs. Right, Bcl-XL, nestin, and DAPI stained fields were merged. (D) Bcl-XL mRNA expressions in NPCs were measured using RT-PCR. GAPDH was used as control. Results are mean ± S.E.M (n = 5). **P < 0.01 vs. control. Scale bar represents 50 μm.