Figure 4.

Med treatment induces activation of the ROS-JNK-CHOP pathway. (a) K562 or U937 cells were pretreated either with the vehicle or with the mitochondria-specific antioxidant MitoQ (50 μM) for 1 h followed by the Med treatment for 6 h. (b) Cells were pretreated with different antioxidants to study the effect of ROS on Med-induced caspase-3/7, caspase-8, and caspase-9 activation using the Colorimetric Activity Assay kit. (c) Cells were treated with different doses of Med for 48 h and JNK activation was determined using western blot. (d) To study the ROS-dependent JNK activation, the cells were pretreated with the indicated antioxidants before Med treatment and western blot analysis of whole-cell lysates were performed. (e) K562 (upper) and U937 (lower) cells were pretreated with NAC and JNK inhibitor (SP600125) and western blotting was performed for CHOP expression. Representative western blots images of three independent experiments are presented. Data are presented as mean±S.D. of three independent experiments.*P>0.05, **P>0.001, ***P>0.0001 in treated groups versus control group