Long-Term Cold Adaptation Does Not Require FGF21 or UCP1

Publication date: 1 August 2017
Source:Cell Metabolism, Volume 26, Issue 2
Author(s): Susanne Keipert, Maria Kutschke, Mario Ost, Thomas Schwarzmayr, Evert M. van Schothorst, Daniel Lamp, Laura Brachthäuser, Isabel Hamp, Sithandiwe E. Mazibuko, Sonja Hartwig, Stefan Lehr, Elisabeth Graf, Oliver Plettenburg, Frauke Neff, Matthias H. Tschöp, Martin Jastroch
Brown adipose tissue (BAT)-dependent thermogenesis and its suggested augmenting hormone, FGF21, are potential therapeutic targets in current obesity and diabetes research. Here, we studied the role of UCP1 and FGF21 for metabolic homeostasis in the cold and dissected underlying molecular mechanisms using UCP1-FGF21 double-knockout mice. We report that neither UCP1 nor FGF21, nor even compensatory increases of FGF21 serum levels in UCP1 knockout mice, are required for defense of body temperature or for maintenance of energy metabolism and body weight. Remarkably, cold-induced browning of inguinal white adipose tissue (iWAT) is FGF21 independent. Global RNA sequencing reveals major changes in response to UCP1- but not FGF21-ablation in BAT, iWAT, and muscle. Markers of mitochondrial failure and inflammation are observed in BAT, but in particular the enhanced metabolic reprogramming in iWAT supports the thermogenic role of UCP1 and excludes an important thermogenic role of endogenous FGF21 in normal cold acclimation.

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Teaser

Using UCP1-FGF21 double-knockout mice, Keipert et al. report that neither UCP1 nor FGF21, nor even compensatory increases of FGF21 serum levels in UCP1 knockout mice, are required for defense of body temperature or for maintenance of energy metabolism and body weight.


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