Glucocorticoid Repression of Inflammatory Gene Expression Shows Differential Responsiveness by Transactivation- and Transrepression-Dependent Mechanisms
Figure 5
Effect of CHX on dexamethasone-dependent repression of inflammatory gene expression.
A549 cells were treated with IL-1β (1 ng/ml) (not shown), or IL-1β and dexamethasone (dex) (1 µM) in the absence or presence of cycloheximide (CHX) (100 µg/ml) as indicated, for 4 h. Cells were then harvested for RNA and real-time PCR carried out for the indicated genes and GAPDH. Data (n = 4) normalised to GAPDH and plotted as percentage of IL-1β or IL-1β+CHX are expressed as mean ± S.E. Significance, relative to IL-1β+dex, using a paired t-test is indicated; *, P<0.05; **, P<0.01; ***, P<0.001. A. Full reversal (significantly different from IL-1β+dex and from IL-1β+CHX), B. partial reversal (significantly different from only IL-1β+dex) and C. no reversal (not significantly different from IL-1β+dex) of dexamethasone-dependent repression by CHX.