Fibroblast growth factor 15 (FGF15)

Fibroblast growth factor 15 (FGF15) is a mouse-specific endocrine growth factor and member of the broader fibroblast growth factor family; it is produced mainly in the ileum in response to bile acid absorption. FGF15 circulates in the blood and binds to liver FGFR4/β-Klotho complexes, leading to the repression of bile acid synthesis, regulation of glucose metabolism, and modulation of energy balance. FGF15 is also implicated in embryonic organ development and liver regeneration. The human ortholog is FGF19, which fulfills analogous biological roles. FGF15 is considered a therapeutic target in animal models for metabolic and liver disorders, but human drug development targets FGF19 due to lack of FGF15 in humans.

Other names

FGF15 (mouse)Fibroblast growth factor 19 (FGF19; functional human ortholog, sometimes "FGF15/19" used to describe both)

Acts as a hormone: FGF15 (or FGF19 in humans) binds to FGFR4/β-Klotho complexes on liver cells, represses transcription of the Cyp7a1 gene, reducing bile acid synthesis. Modifies hepatic glucose metabolism via activation of hepatic signaling pathways. Promotes hepatocyte proliferation and liver repair through direct receptor-mediated signal transduction.