Fig. 4

Expression of NOX2 and its regulators is mediated through p38 and NF-κB, whereas MMP-7 expression is mediated through MAPKs, AP-1, and NF-κB. Protein extracts from cells treated with TPA (12 ng/ml) alone or TPA with various inhibitors were examined for phosphorylation of MAPKs (a), expression of NOX2, its regulators, and MMP-7 (b and d), and nuclear translocation of the transcription factors NF-κB and AP-1 (c). PD, SP, SB, and SR represent 10 μM PD98059, SP600125, SB203580, and SR11302, respectively. The bar graphs indicate the mean ± SEM of relative densities of protein expression. e The luciferase reporter plasmid containing human NF-κB or AP-1 response element was transiently transfected, and reporter activity was assessed following incubation of transfected cells with TPA for 3 h. Various inhibitors were pretreated 1 h before TPA treatment. Values are the mean ± SEM from three independent experiments. *P < 0.05 compared to vehicle-treated control group. ^# P < 0.05 compared to TPA-treated group