Figure 3

The ERK and the PI3K/Akt pathways are involved in DEP-induced IL-8 and IL-1β expression. A, Confluent HBEC were exposed to 50 μg/ml DEP for 1-4 h. Supernatants of cell lysates were subjected to SDS–PAGE and immunoblotting using phospho- and pan antibodies against ERK. B, HBEC were pretreated with vehicle (DMSO), or 20 μM ERK kinase inhibitor U0126, for 30 min prior to 50 μg/ml DEP stimulation for 24 h, respectively. Levels of IL-8 and IL-1β proteins were determined using ELISA and expressed as fold over control. *P < 0.05, compared to DEP treatment in the vehicle (DMSO) group. C, Confluent HBEC were exposed to 50 μg/ml DEP for 1-4 h. Phosphorylated Akt was determined using immunoblotting and phospho-specific antibody against Akt. D, HBEC were pretreated with vehicle (DMSO), or 1 μM PI3K inhibitor Wortmannin, for 30 min prior to 50 μg/ml DEP stimulation for 24 h, respectively. Levels of IL-8 and IL-1β proteins were measured using ELISA and expressed as fold over control (DEP vs. PBS control in vehicle DMSO or inhibitor group, respectively). * P < 0.05, compared to DEP treatment in the vehicle (DMSO) group.