Defining the Nutritional and Metabolic Context of FGF21 Using the Geometric Framework

Cell Metab. 2016 Oct 11;24(4):555-565. doi: 10.1016/j.cmet.2016.09.001. Epub 2016 Sep 29.

Abstract

Fibroblast growth factor 21 (FGF21) is the first known endocrine signal activated by protein restriction. Although FGF21 is robustly elevated in low-protein environments, increased FGF21 is also seen in various other contexts such as fasting, overfeeding, ketogenic diets, and high-carbohydrate diets, leaving its nutritional context and physiological role unresolved and controversial. Here, we use the Geometric Framework, a nutritional modeling platform, to help reconcile these apparently conflicting findings in mice confined to one of 25 diets that varied in protein, carbohydrate, and fat content. We show that FGF21 was elevated under low protein intakes and maximally when low protein was coupled with high carbohydrate intakes. Our results explain how elevation of FGF21 occurs both under starvation and hyperphagia, and show that the metabolic outcomes associated with elevated FGF21 depend on the nutritional context, differing according to whether the animal is in a state of under- or overfeeding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activating Transcription Factors / genetics
  • Activating Transcription Factors / metabolism
  • Animal Nutritional Physiological Phenomena*
  • Animals
  • Appetite
  • Dietary Proteins / metabolism
  • Energy Metabolism
  • Female
  • Fibroblast Growth Factors / blood
  • Fibroblast Growth Factors / metabolism*
  • Gene Expression Regulation
  • Glucose / metabolism
  • Insulin-Like Growth Factor I / metabolism
  • Male
  • Mice, Inbred C57BL
  • Models, Biological
  • Phenotype
  • Uncoupling Protein 1 / metabolism

Substances

  • Activating Transcription Factors
  • Atf5 protein, mouse
  • Dietary Proteins
  • Uncoupling Protein 1
  • fibroblast growth factor 21
  • Fibroblast Growth Factors
  • Insulin-Like Growth Factor I
  • Glucose