FIGURE 4.
A, Effect of adenosine (ADO, 100 μM) and/or LPS (LPS, 10 μg/ml) on luciferase activity in RAW 264.7 cells transfected with a IL-10 luciferase reporter plasmid containing the entire 3′-UTR of IL-10 (AU4) downstream of the luciferase gene. Luciferase activity was measured from cells lysed 9 h after transfection with AU4 and normalized to protein content. ADO or LPS were administered 4 h after the transfection. B, Effect of ADO or LPS on luciferase activity in RAW 264.7 cells transfected with the pGL3-control luciferase vector. Luciferase activity was measured from cells lysed 9 h after transfection and normalized to protein content. ADO or LPS were administered 4 h after the transfection. C, ADO augments luciferase activity in RAW 264.7 cells transfected with IL-10 luciferase reporter plasmids containing various regions of the 3′-UTR of IL-10 (AU1–3) downstream of the luciferase gene. Luciferase activity was measured from cells lysed 9 h after transfection and normalized to protein content. ADO was administered 4 h after the transfection. D, The p38 MAPK inhibitor SB203580 (SB, 1 μM) cotreatment fails to decrease the ADO-stimulated increase in AU4 luciferase activity. Results (mean ± SEM) shown are representative of at least three experiments with n = 4 in each experiment. **, p < 0.01; con, control.