Fig. 3
Apremilast inhibits lipopolysaccharide (LPS)-induced TNF-α release via cyclic adenosine monophosphalphate (cAMP). a Western blot of PDE4 was performed in the Raw 264.7 cell line. b Raw 264.7 cells were incubated with increasing concentrations of apremilast 30 minutes before incubation with or without LPS 1 μM during 20 minutes. Intracellular cAMP levels were then measured as described under “Materials and methods”. c Western blot of p-cAMP responsive element binding protein (p-CREB) and CREB shows that apremilast promotes CREB phosphorylation after incubation with LPS 1 μg/ml for 30 minutes. d Cumulative concentration response curves to apremilast (6 nM−1 μM) were performed in the Raw 264.7 cells 30 minutes before incubation with LPS 1 μM during 4 h. IC50 values were determined as described under “Materials and methods”. Data represent means ± standard error of the mean of four independent experiments. Statistical analysis was performed by two-way ANOVA: apremilast ***P <0.001, LPS: not significant. PDE4 phosphodiesterase 4,