FGF-21 (human) (rec.)

The fibroblast growth factor (FGF) family is a group of multifunctional signaling molecules that have a wide variety of functions. The family comprises of 22 related proteins, each grouped into subfamilies which are based on genetic and functional similarity. FGF21 is expressed in several tissues such as liver (main site), muscles, adipocytes, pancreas, and brain where it passes the blood-brain barrier. FGF-21 stimulates glucose uptake in differentiated adipocytes via the induction of glucose transporter SLC2A1/GLUT1 expression. Its activity requires the presence of the FGFR1 and β-klotho. FGF21 mediates the adaptive starvation response to induce ketogenesis, gluconeogenesis, lipolysis, and lipid β-oxidation. FGF21 plays also a key role in cardiac remodeling with the heart expressing fibroblast growth factor receptor 1 (FGFR1), β-klotho, as well as FGF21. In muscle, FGF21 expression in skeletal muscles is due to mitochondrial dysfunction and ER stress.