AMPK suppressed MKP-3 expression independent of leptin signaling. (A) MKP-3 protein level in primary hepatocytes that were treated with 1 mmol/L AICAR or vehicle for 1 hour. (B) MKP-3 protein level in primary hepatocytes that were treated with 0.5 mmol/L metformin or vehicle for 1 hour. (C) MKP-3 protein level in 10 μmol/L compound C or vehicle-treated primary hepatocytes. (D) MKP-3 protein level in AdGFP, AdCA-AMPKα1, or AdDN-AMPKα1–infected hepatocytes. (E and F) MKP-3 protein level in AICAR or vehicle-treated and AdGFP or AdDN-AMPKα1–infected primary hepatocytes. (G and H) Protein levels in AdGFP- or AdOBRb- and Adb-gal- or AdDN-AMPKα1-infected hepatocytes. ∗P < .05, ∗∗P < .01 as marked. Results for cell studies represent 1 of 3 independently performed experiments. AdCA-AMPKα1, adenovirus cloned with constitutively activating mutation of AMPKα1; CC, compound C; Met, metformin; Veh, vehicle.