PARP inhibition by PJ-34 (30 µM) fails to affect p42/44 MAPK (ERK1/2) and JNK activation or the activation of p38 in immunostimulated J774 cells. Lanes 1 and 2, no stimulation; lanes 3 and 4, 10 µg/ml LPS; lanes 5 and 6: PJ-34 pretreatment 30 min before LPS. The activation of p42/44, JNK, and p38 was determined with Western blotting using antibodies raised against the phosphorylated (active) forms of p42/44, JNK, and p38. Cellular extracts were obtained 15 min after stimulation with LPS. This figure is representative of two different experiments.