Fig. 4

NF-κB activation was involved in O-PMs-induced ICAM-1 expression in A549 cells. a The effects of O-PMs treatment on translocation of NF-κB p65 in A549 cells. A549 cell were treated with or without 100 μg/ml O-PMs for 24 h. The distribution of p65 in the cytosolic (C) and nuclear (N) portion of A549 cells was determined by Western blot. *p < 0.05 vs. the cytosolic portion. †p < 0.05 vs. compared to the nuclear portion. b A549 cells were transfected with various concentrations of siRNA of p65 for 48 h. Levels of p65 were determined by Western blot. *p < 0.05 vs. 0 (untransfected cells). c After the transfection of p65 siRNA for 24 h, A549 cells were then stimulated with 100 μg/ml O-PMs for 24 h. The ICAM-1, p-AKT and p-STAT3 expression was determined by Western blot. *p < 0.05 vs. Con. †p < 0.05 vs. O-PMs. d Representative fluorescence photomicrographs and quantitative data showing the effects of AKT, NF-κB, and STAT3 on the adhesion of BCECF-AM-labeled U937 cells to O-PMs-treated A549 cells. Cells were pretreated for 1 h with BAY11–7082 (10 μM), LY294002 (10 μM), Stattic (10 μM) or p65 siRNA. Then they were treated with 100 μg/ml O-PMs for 24 h in the continued presence of the inhibitor. The cells without any treatment were used as the control (Con). BCECF-AM-labeled U937 cells were added to A549 cells and were incubated at 37 °C for 1 h. The adherent cells were photographed with a fluorescent microscope. Bar = 125 mu. *p < 0.05 vs. Con. †p < 0.05 vs. O-PMs