Apremilast, a novel phosphodiesterase 4 (PDE4) inhibitor, regulates inflammation through multiple cAMP downstream effectors
Introduction This work was undertaken to delineate intracellular signaling pathways for the PDE4 inhibitor apremilast and to examine interactions between apremilast, methotrexate and adenosine A2A receptors (A2AR). Methods After apremilast and LPS incubation, intracellular cAMP, TNF-α, IL-10, IL-6 and IL-1α were measured in the Raw264.7 monocytic murine cell line. PKA, Epac1/2 (signaling intermediates for cAMP) and A2AR knockdowns were performed by shRNA transfection and interactions with A2AR and A2BR, as well as with methotrexate were tested in vitro and in the murine air pouch model. Statistical differences were determined using one or two-way ANOVA or Student’s t test. The alpha nominal…
Additional file 1: Figure S1. of Apremilast, a novel phosphodiesterase 4 (PDE4) inhibitor, regulates inflammation through multiple cAMP downstream effectors
Adenosine A2A receptor (A2AR) activation and apremilast do not additively increase responsive element binding protein (cAMP). Raw 264.7 cells were incubated with cumulative concentrations of apremilast (6 nM to 1 μM), apremilast + CGS21680 1μM 15 minutes before apremilast, or cumulative concentrations of CGS21680 alone (6 nM to 1 μM), followed by treatment with lipopolysaccharide (LPS) 1 μM for 20 minutes. Then, intracellular cAMP levels were measured as described under “Materials and methods”. Data represent means ± standard error of the mean of at least three independent experiments. (TIFF 170 kb)