fibroblast growth factor 19

Fibroblast growth factor 19 is a human protein hormone encoded by the FGF19 gene. It is a member of the fibroblast growth factor (FGF) family, acting primarily as an **endocrine regulator of bile acid synthesis** via high-affinity binding to the fibroblast growth factor receptor 4 (FGFR4) and the co-receptor Klotho-β in the liver. FGF19 is produced in the ileum in response to bile acid absorption and mediates feedback inhibition of bile acid synthesis by downregulating CYP7A1 in the liver. This protein also has broad metabolic effects, including regulation of **glucose and lipid metabolism**, modulation of energy expenditure, and promotion of glucose uptake in adipocytes. Exogenously administered recombinant FGF19 has demonstrated **hepatoprotective effects** in preclinical models of acute and chronic liver injury, and can reduce hepatic steatosis, promote liver regeneration, and improve markers of metabolic syndrome and muscle wasting in experimental models. Potential risks associated with FGF19 include mitogenic stimulation of hepatocytes, which may increase the risk of hepatocellular carcinoma upon prolonged or high-level exposure. Non-tumorigenic variants of FGF19 have been engineered for translational applications to mitigate this risk. FGF19 and its analogs are in various stages of development for indications such as nonalcoholic steatohepatitis (NASH), diabetes, obesity, liver cirrhosis, cholestasis, and sarcopenia. No recombinant FGF19 product has yet been approved for clinical use.

Other names

FGF19FGF-19FGF 19fibroblast growth factor 19 protein