In Vitro and in Vivo Analyses Reveal Profound Effects of Fibroblast Growth Factor 16 as a Metabolic Regulator.

The discovery of brown adipose tissue (BAT) as a key regulator of energy expenditure has sparked interest in identifying novel soluble factors capable of activating inducible BAT (iBAT) to combat obesity. Using a high content cell-based screen, we identified fibroblast growth factor 16 (FGF16) as a potent inducer of several physical and transcriptional characteristics analogous to those of both "classical" BAT and iBAT. Overexpression of Fgf16 in vivo recapitulated several of our in vitro findings, specifically the significant induction of the Ucp1 gene and UCP1 protein expression in inguinal white adipose tissue (iWAT), a common site for emergent active iBAT.