ATP-derived adenosine attenuates inflammatory cytokine production via A2bR signaling. (A) Adenosine receptor mRNA expression in naïve (gray bars) or LPS-stimulated (black bars) BMDMs at 4 hours poststimulation. The means ± SD of duplicates are shown and are representative of 3 independent experiments. (B) mRNA expression of A1r (black, closed squares; black line), A2ar (black, closed circles; black line), A2br (gray closed squares; gray, dashed line), and A3r (black, closed diamonds; black line) in BMDMs stimulated with LPS over time. The means ± SD of duplicates are shown and are representative of 3 independent experiments. (C) The percent of LPS-induced cytokine transcript expression modulated by 100 μM ATP in wild-type (solid bars) or A2br^−/− (striped bars) BMDMs 4 hours poststimulation. The dashed line represents mRNA expression in BMDMs stimulated with LPS alone. The means of 3 independent experiments ± SEM are shown. (D) The percent of LPS-induced cytokine produced in the presence of 100 μM ATP in wild-type (solid bars) or A2br^−/− (striped bars) BMDMs was determined by ELISA at 16 hours poststimulation. The dashed line represents cytokine production induced by LPS alone. The means ± SD of triplicates are shown and are representative of 2 independent experiments. (E) A2ar and A2br mRNA expression in wild-type (solid bars) and A2br^−/− (striped bars) BMDMs unstimulated (gray bars) or stimulated with LPS (black bars) was determined by qRT-PCR at 4 hours poststimulation. The means ± SD of duplicates are shown and are representative of 3 independent experiments. WT, wild-type.