Fig. 3

Cytokines activated the NF-κB and MAP kinase pathways in A549 cells. A549 cells were stimulated with BSA (vehicle control) or CM at time 0. Total cell lysates were collected at the indicated time points and then subjected to western blotting using the indicated antibodies. Upper panel shows the phosphorylation of NF-κB (p-NFκB) peaked at 15 min after CM stimulation and sustained at least for 1 h. IκBα rapidly degraded within 15 min after CM stimulation and recovered gradually. Lower panel shows the maximum phosphorylation was observed between 15 min and 30 min for ERK, JNK, and p38 after CM stimulation. Weak activation of ERK was also observed after vehicle (BSA) treatment alone. The total protein amounts of each MAP kinase were unchanged during the observed period