Figure 5. Epoxygenase inhibition in alternatively activated monocytes inhibits TNFα release: a role for superoxide generation.

(A) shows the acute release of TNFα from THP-1 cells over 7 h with vehicle treatment (Cont), or treated with SKF525A (10 µM), IL-4 (20 ng/ml), the superoxide dismutase, MnCl₂ (10 µM) or a combination of IL-4 and SKF525A or IL-4 and MnCL₂. (B) shows inhibition of basal TNFα release from THP-1 cells treated with 11,12-EET or 8,9-EET (1 µM) in the presence of absence of SKF (10 µM) with IL-4 (20 ng/ml). Data represents mean ± SEM of n = 3 experiments. * indicates EET difference from control, while † indicates EET difference from IL-4 with SKF525A. (C) shows the production of superoxide (left figure; arbitrary units), or representative florescent micrographs (right panels), from THP-1 cells treated for 7 h with vehicle treatment (Cont), SKF525A (10 µM), IL-4 (20 ng/ml), or a combination of IL-4 and SKF525A. The superoxide sensor, dihydroethidium (10 µM) was added for the last 30 min and staining intensity analyzed using a Nikon TE2000 inverted florescent microscope connected to a SPOT-RT digital camera. Data represents mean ± SEM of n = 3−4 experiments. *denotes p<0.05, by one-way ANOVA and Bonferroni's post-test compared to control cells.