(A) RAW264.7 cells were primed with LPS (1 μg/mL, 2h). Sucrose lysates were incubated with recombinant active caspase-1 (1 U/50 μL, 3 h, 37°C) in the presence or absence of 15d-PGJ2 at indicated concentrations or positive control caspase-1 inhibitor Boc-D-CMK (400 μM). (B) RAW264.7 cells were primed with LPS (1 μg/mL, 2 h) followed by treatment with 15d-PGJ2 (50 μM, 1 h). As above, sucrose lysates were incubated with recombinant active caspase-1. In all panels, IL-1β processing was observed by Western blot. The * indicates a cross-reactive protein band which acts as an internal equal loading control. Western results are representative of at least three similar experiments.