A Specific ChREBP and PPARα Cross-Talk Is Required for the Glucose-Mediated FGF21 Response

Abstract

Summary: While the physiological benefits of the fibroblast growth factor 21 (FGF21) hepatokine are documented in response to fasting, little information is available on Fgf21 regulation in a glucose-overload context. We report that peroxisome-proliferator-activated receptor α (PPARα), a nuclear receptor of the fasting response, is required with the carbohydrate-sensitive transcription factor carbohydrate-responsive element-binding protein (ChREBP) to balance FGF21 glucose response. Microarray analysis indicated that only a few hepatic genes respond to fasting and glucose similarly to Fgf21. Glucose-challenged Chrebp−/− mice exhibit a marked reduction in FGF21 production, a decrease that was rescued by re-expression of an active ChREBP isoform in the liver of Chrebp−/− mice. Unexpectedly, carbohydrate challenge of hepatic Pparα knockout mice also demonstrated a PPARα-dependent glucose response for Fgf21 that was associated with an increased sucrose preference. This blunted response was due to decreased Fgf21 promoter accessibility and diminished ChREBP binding onto Fgf21 carbohydrate-responsive element (ChoRE) in hepatocytes lacking PPARα. Our study reports that PPARα is required for the ChREBP-induced glucose response of FGF21. : FGF21 is a hepatokine with beneficial metabolic effects, including control of sucrose preference. Iroz et al. demonstrate that Fgf21 is a unique hepatic gene inducible by both fasting and glucose signals and that the transcription factors PPARα and ChREBP both regulate the endocrine control of sugar intake by hepatic FGF21. Keywords: ChREBP, PPARα, FGF21, glucose intake, sucrose preference