Figure 2.

miR-155 is downstream of the glucocorticoid receptor in differentiating preadipocytes. (a) Murine 3T3-L1 preadipocytes were induced to differentiate in the presence of 500 µM IBMX (M), 100 nM insulin (I), and supplemented with either solvent control (MI) or 250 nM dexamethasone (MID) for 4 and 8 hours. At each time point, miRNA was isolated, and the expression levels of miR-155 were quantified by real-time qPCR. Levels were normalized to endogenous RNU6 and expressed as fold over MI at 4 hours. Results from 3 separate experiments are graphically represented as mean ± S.E.M. (b) Murine 3T3-L1 preadipocytes were induced to differentiate in the presence of 500 µM IBMX (M), 100 nM insulin (I), and supplemented with either solvent control (MI) or 250 nM dexamethasone (MID). Glucocorticoid receptor inhibitor RU486 (1 µM) or vehicle (Veh; ethanol) were added to MI and MID conditions as indicated. After 8 hours miRNA was isolated and, real-time qPCR quantified the expression levels of miR-155. Levels were normalized to endogenous RNU6 and expressed as fold over MI+Veh. Results from 3 separate experiments are graphically represented as mean ± S.E.M. **Denotes p < 0.01, as assessed by one-way ANOVA with Tukey’s post-hoc tests.