Fig. 5.

MAPK activation during TVX exposure and involvement in TVX-induced TNF mRNA expression. RAW cells were treated with VEH or TVX and with MAPK inhibitors or their dimethylsulfoxide (DMSO) vehicle. Cells were lysed at the indicated times, and MAPK phosphorylation was evaluated in protein extracts. RNA was isolated after a 2-hour incubation with VEH or TVX and with DMSO or MAPK inhibitors, and TNF mRNA was assessed by quantitative PCR. (A) RAW cells were treated with U0126 (500 nM), and extracts were probed for phosphorylated ERK and total ERK. Values for phosphorylated ERK were normalized to values for total ERK. (B) TNF mRNA expression from RAW cells exposed to TVX and U0126 (500 nM). (C) RAW cells were treated with SP600126 (10 μM), and extracts were probed for phospho-ATF2 and total ATF2. Values for phospho-ATF2 were normalized to values for total ATF2. (D) TNF mRNA expression in RAW cells exposed to SP600125 (10 μM). (E) RAW cells were treated with SB203580 (10 μM), and extracts were probed for phosphorylated p38, MAPKAPK-2, ATF2, and total p38. Values for phosphorylated p38 were normalized to values for total p38. (F) TNF mRNA expression in RAW cells exposed to SB203580 (10 μM). All data are represented as means ± S.E.M. of normalized densitometry (n = 3–6). a, P < 0.05 versus VEH within a time point or VEH/DMSO; b, P < 0.05 versus TVX/DMSO; c, P < 0.05 versus VEH/MAPK inhibitor.