D12942

Hepatocyte‐specific Mouse Ddx17 conditional knockout mouse strains (Ddx17‐CKO) were acquired from Cyagen (CKOAI190719XW1‐B; Cyagen). Male 6−8 week‐old mice were subjected to either a HFD (Research Diets, NJ, USA; catalog number D12942) or a ND treated as controls for 24 weeks. The MCD model was fed with an MCD diet (Research Diets; A02082002BR/A06071301B) for 16 weeks. Meanwhile, 8‐week‐old male Ob/ob and lean mice that were purchased from Beijing HFK Bioscience (Beijing, China) were fed with a ND. All mice were housed in a controlled environment with temperatures maintained at 22−24°C and subjected to a 12‐h light–dark cycle. Mice were provided with humane care in accordance with guidelines established by the National Institutes of Health. All experiments involving mice were performed with approval from the Tongji Hospital Animal Care and Use Committee (TJH‐202101106).

DPP IV (lyophilized powder, ≥ 10 units/mg protein, D-7052), glucose, Gly-Pro p-nitroanilide, pepsin (3460 units/mg solid, P-6887), and sitagliptin phosphate were purchased from Sigma Chemical Co. (St. Louis, MO). The HF diet for obesity induction (fat composition provide 60% of total calories, D12942) was purchased from Research Diets, Inc. (NJ, USA). The standard mouse/rat chow (fat composition provide 12.137% of total calories, Prolab® RMH2500, 5P14 Diet; PMI Nutrition International, MO, USA).