Figure 8.
DFO inhibits the MAF02-induced formation of ROS, mobilization of AA, PGE2/TXB2 and phosphorylation of ERK1/2. (A) Adherent H2DCF-loaded RAW264.7 cells were incubated with DFO before treatment with 10, 25, 50, 100, 200 and 300 μg/ml MAF02 particles (6.3, 12.6, 31.3, 62.5, 125, 188 μg/cm2) for 2.5 hours. Values are expressed as a percentage of the untreated controls. For analysis of ERK1/2 (B), JNK (E), and c-Jun phosphorylation non-labelled cells were pre-incubated with various concentrations of DFO and subsequently exposed with 50 μg/ml MAF02 particles (15.6 μg/m2) for 2.5 hours. Whole cell lysates were analyzed by Western blotting. OD-band intensities of phosphorylated proteins, analyzed by Odyssey® software, were normalized to the respective loading control protein and expressed in relation to the maximum band intensity of the MAF02-treated sample (100%). [14C]arachidonic acid-labelled RAW264.7 macrophages were treated with DFO before exposure with 50 μg/ml MAF02 particles (13.2 μg/m2) for 2.5 hours. After lipid extraction, the free arachidonic acid and its metabolites were separated by TLC, visualized by autoradiography and analyzed by OptiQuant® software. Data on AA (C) and PGE2/TXB2 (D) liberation are expressed as percentage of control cells (100% values). Results are presented as the mean ± s.e.m. of three independent experiments (* p < 0.05, **p < 0.01, p*** < 0.001 compared to 50 μg/ml MAF02-treated cells).