Tianru Jin

Metabolic functions of GLP‐1 and its analogues have been extensively investigated. In addition to acting as an incretin and reducing body weight, we and others have suggested the existence of GLP‐1/fibroblast growth factor 21 (FGF21) axis in which liver mediates certain functions of GLP‐1 receptor agonists. In a more recent study, we found with surprise that four‐week treatment with liraglutide but not semaglutide stimulated hepatic FGF21 expression in HFD‐challenged mice. We wondered whether semaglutide can also improve FGF21 sensitivity or responsiveness and hence triggers the feedback loop in attenuating its stimulation on hepatic FGF21 expression after a long‐term treatment. Here, we assessed effect of daily semaglutide treatment in HFD‐fed mice for 7 days. HFD challenge attenuated effect of FGF21 treatment on its downstream events in mouse primary hepatocytes, which can be restored by 7‐day semaglutide treatment. In mouse liver, 7‐day semaglutide treatment stimulated FGF21 as well as genes that encode its receptor (FGFR1) and the obligatory co‐receptor (KLB), and a battery of genes that are involved in lipid homeostasis. In epididymal fat tissue, expressions of a battery genes including Klb affected by HFD challenge were reversed by 7‐day semaglutide treatment. We suggest that semaglutide treatment improves FGF21 sensitivity which is attenuated by HFD challenge.