Figure 2. AMPK activation is involved in TGF-β1-induced FOXO3 synthesis. (A-D) OASFs were pretreated with AMPK inhibitors (Ara A and compound C) or transfected with AMPKα1 and α2 siRNAs, then incubated with TGF-β1 (10 ng/ml). The mRNA and protein levels were examined by qPCR and Western blot. (E) OASFs were incubated with TGF-β1 for the indicated time intervals, and the extent of AMPK phosphorylation was examined by Western blot. (F) Cells were serum starvation for 24 h, the AMPK phosphorylation and indicated mRNA expression were examined by Western blot and qPCR. 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.