Flagellin activates pro-apoptotic signaling in mouse tissues. Cleavage of caspase-3 and poly(ADP-ribose) polymerase (PARP; immunoblotting) in mouse organs at baseline (time 0), and at one and three hours after flagellin (5 μg). Caspase-3 and PARP were cleaved slightly at one hour in the liver and lung, and strongly at three hours in the gut. No cleavage of caspase-3 was noted in the kidney, which disclosed a discrete cleavage of PARP at one hour. Procaspase-3 and uncleaved PARP did not change over time, except in the gut where both decreased after three hours. Blots are representative of at least three independent experiments.