FIGURE 2.
TNFAIP3 is required for maximal repression of cytokines by glucocorticoids. A and B, Beas-2B cells were transfected with siRNA against TNFAIP3 (si-TNFAIP3) or control (si-Ctrl) and then treated with TNF, dex, or TNF + dex for 4 or 24 h. Transcript levels of indicated proinflammatory genes were assessed by qRT-PCR and are presented as the mean CT values (±S.D.) relative to si-Ctrl + vehicle-treated controls. For a specific gene, 100% repression is defined as TNF + dex treatment resulting in base-line expression levels in comparison to TNF treatment under the same conditions. Percent repression for each assayed gene is indicated in the figure above the TNF + dex columns. C, cells were transfected as described above and treated for 24 h with TNF, dex, or TNF + dex as indicated. IL8 levels in the supernatant were measured using ELISA, and percent repression is indicated. D, Western blots for TNFAIP3 and β-actin (loading control) proteins confirming knockdown by si-TNFAIP3 in the experiment described in C. Relative positions of standard weight markers in kilodaltons are as indicated to the right of the blot. Statistical comparisons for each panel are as follows: A and B, *, p ≤ 0.05 versus si-Ctrl with TNF + dex treatment for the same gene (shaded green versus solid green bars); C, *, p ≤ 0.05 versus si-Ctrl with TNF + dex treatment.