OPN activates JNKs and increases Bax expression and levels of cytosolic cytochrome c. ARVMs were treated with OPN for 15 min (A), 3 h (B and C), or 6 h (D). Cell lysates were analyzed by Western blots using anti p-JNKs (A), anti-Bax (B), anti-Bcl2 (C), or anti-cyotchrome c (D) antibodies. Protein loading was normalized using total JNKs or GAPDH immunostaining. Bottom: mean data normalized to JNKs or GAPDH. *P < 0.05 vs. CTL; n = 3 to 4.