Fig. 3.
Inhibition of JNK-2 in CF cells has a different effect on IL-8 mRNA stability from that of p38 and ERK1/2. IB3-1 cells (A) or IB3-1-TTP cells (B) were treated with the chemical inhibitor SP-600125 (10 μM) or transiently transfected with dominant negatives (JNK-APF and MEK-7; ∼1 μg/1.5 × 106 cells) for JNK signaling pathway. RNA was isolated from IB3-1 and IB3-1-TTP cells after actinomycin D treatment for the indicated time intervals, and the remaining mRNA was analyzed by quantitative real-time PCR. The data reflect averages of at least 3 independent experiments (*P < 0.05 and **P > 0.05). C: IL-8 protein secreted by both cell types was analyzed by ELISA 16 h after transfection.