HO-1 Induction by CO-RM2 Attenuates TNF-α-Induced Cytosolic Phospholipase A2 Expression via Inhibition of PKCα-Dependent NADPH Oxidase/ROS and NF-κB
Figure 1
CORM-2 enhances HO-1 expression and modulates TNF-α-induced cPLA2 expression in RASFs. RASFs were treated with (a) different concentrations or (b) 25 μM of CORM-2 for the indicated time intervals. (c) RASFs were incubated with various concentrations of TNF-α for the indicated time intervals. (d) Cells were incubated with TNF-α (30 ng/mL) for the indicated time intervals. The mRNA levels of cPLA2 and cPLA2-Luc promoter were measured. (e) Cells were pretreated with different concentrations of CORM-2 for 16 h and then incubated with TNF-α for 16 h. Cells were pretreated with (f) CORM-2 or iCORM-2 or (h) were transfected with scrambled (scrb) or HO-1 siRNA and then incubated without or with TNF-α for 16 h. ((a), (c), (e), (f), and (h)) The cell lysates were analyzed by Western blotting using an anti-cPLA2, anti-HO-1, or anti-GAPDH (control). ((g), open bars) RASFs were pretreated without or with CORM-2, or iCORM-2 for 16 h, and incubated with TNF-α (30 ng/mL) for 6 h. cPLA2 mRNA was analyzed by quantitative real-time PCR. ((g), shaded bars) RASFs were transfected with a cPLA2-Luc reporter gene, pretreated without or with CORM-2 or iCORM-2 for 16 h, and incubated with TNF-α (30 ng/mL) for 6 h. Promoter luciferase activity was analyzed. All analyses were performed on samples from 4 RA patients. Results are representative of 3 independent experiments. Values are the mean ± SEM. ((b)–(d)) ; , as compared with the cells exposed to vehicle alone; ((e)–(g)) ; as compared with the cells exposed to TNF-α alone.
