Figure 3. The p38 pathway is involved in TGF-β1-induced FOXO3 production. (A-D) OASFs were pretreated with a p38 inhibitor (SB203580) or transfected with p38 siRNA for 24 h, then incubated with TGF-β1 (10 ng/ml) for 24 h. The mRNA and protein levels were examined by qPCR and Western blot. (E) OASFs were incubated with TGF-β1 for the indicated time intervals; the extent of p38 phosphorylation was examined by Western blot. (F) OASFs were pretreated with AMPK inhibitors for 24 h, then incubated with TGF-β1 (10 ng/ml). The p38 phosphorylation was examined by Western blot. Results are expressed as the mean ± SEM. *p < 0.05 as compared with the control group; #p < 0.05 as compared with the TGF-β1-treated group.