Work

Hepatic insulin signalling is dispensable for suppression of glucose output by insulin in vivo

Year: 2015

Type: article

Abstract: Insulin signalling and nutrient levels coordinate the metabolic response to feeding in the liver. Insulin signals in hepatocytes to activate Akt, which inhibits Foxo1 suppressing hepatic glucose production (HGP) and allowing the transition to the postprandial state. Here we provide genetic evidence that insulin regulates HGP by both direct and indirect hepatic mechanisms. Liver-specific ablation of the IR (L-Insulin Receptor KO) induces glucose intolerance, insulin resistance and prevents the appropriate transcriptional response to feeding. Liver-specific deletion of Foxo1 (L-IRFoxo1DKO) rescues glucose tolerance and allows for normal suppression of HGP and gluconeogenic gene expression in response to insulin, despite lack of autonomous liver insulin signalling. These data indicate that in the absence of Foxo1, insulin signals via an intermediary extrahepatic tissue to regulate liver glucose production. Importantly, a hepatic mechanism distinct from the IR–Akt–Foxo1 axis exists to regulate glucose production. Insulin and the transcription factor FoxO1 are key regulators of hepatic glucose metabolism. Here, Titchenell et al. provide evidence for the existence of an insulin-dependent extrahepatic pathway that is fully capable of regulating hepatic glucose production in the absence of hepatic FoxO1.

Source: Nature Communications

DOI: 10.1038/ncomms8078

Authors: Paul M. Titchenell, Qingwei Chu, Bobby R. Monks, Morris J. Birnbaum

Institution: University of Pennsylvania

Language: English

Topic: Metabolism, Diabetes, and Cancer

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $6,990