Figure 6.

Effects of ROS scavengers on MG132-induced COX-2 expression and ROS production. (A) Cells were treated with 25 μM MG132, PSI-1, or 200 μM H₂O₂ for 16 h in the presence or absence of pretreatment with 20 mM NAC or GSH for 30 min. Whole-cell lysates were prepared and subjected to Western blotting using antibody specific for COX-2 or actin. (B) Cells were loaded with 10 μM DCF for 1 h and then replaced with fresh medium followed by incubation with 25 μM MG132 or 200 μM H₂ O₂ for 1 h in the present or absence of 20 mM NAC or GSH. Fluorescent images were observed and photographed with a fluorescence microscope as described in Materials and Methods. Results are representative of three independent experiments. (C) The fluorescence intensity were determined with ImageQuant software and represented as means of spots in three independent fields. * p < 0.05; compared with MG132 alone.