Exendin-4 regulates the expressions of TGF-β1, FN, α-SMA, and Col-1 in MCs treated by oleate via AMPK activation. EX: exendin-4; CC: compound C; AI: AICAR. MCs were cultured in DMEM and 1% BSA or 200 μM oleate-BSA for 48 hours. Exendin-4 (20 nM), compound C (10 μM), or AICAR (1 mM) were used to assess the effect of AMPK on myofibroblast marker protein expression. Supernatants were assayed by ELISA after treatment with a different reagent. Western bolt of p-AMPK (a), p-ACC (b), TGF-β1, FN, α-SMA, and Col-1 (c) and quantitative analyses of the results are also shown (d–g). (h) Secreted TGF-β1 in the cell culture supernatants. Values are the mean ± SD of 3 independent experiments. ∗∗P < 0.01 vs. BSA group; &&P < 0.01 vs. OA group; #P < 0.05 and ##P < 0.01 vs. OA+EX group.