Toggle Main Menu Toggle Search

Open Access padlockePrints

High-carbohydrate diets induce hepatic insulin resistance to protect the liver from substrate overload

Lookup NU author(s): Professor Loranne Agius

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Abstract

In population studies hepatic steatosis in subjects with Non-alcoholic fatty liver disease (NAFLD) is strongly associated with insulin resistance. This association has encouraged debate whether hepatic steatosis is the cause or the consequence of hepatic insulin resistance? Although genome-wide studies have identified several gene variants associated with either hepatic steatosis or type 2 diabetes, no variants have been identified associated with both hepatic steatosis and insulin resistance. Here, the hypothesis is proposed that high-carbohydrate diets contribute to. the association between hepatic steatosis and insulin resistance through activation of the transcription factor ChREBP (Carbohydrate response element binding protein). Postprandial hyperglycaemia raises the hepatic concentrations of phosphorylated intermediates causing activation of ChREBP and induction of its target genes. These include not only enzymes of glycolysis and lipogenesis that predispose to hepatic steatosis but also glucose 6-phosphatase (G6PC) that catalyses the final reaction in glucose production and GCKR, the inhibitor of hepatic glucokinase that curtails hepatic glucose uptake. Induction of G6PC and GCKR manifests as hepatic glucose intolerance or insulin resistance. Induction of these two genes by high glucose serves to safeguard intrahepatic homeostasis of phosphorylated intermediates. The importance of GCKR in this protective mechanism is supported by "less-active" GCKR variants in association not only with hepatic steatosis and hyperuricaemia but also with lower fasting plasma glucose and decreased insulin resistance. This supports a role for GCKR in restricting hepatic glucose phosphorylation to maintain intrahepatic homeostasis. Pharmacological targeting of the glucokinase GCKR interaction can favour either glucose clearance by the liver or intrahepatic metabolite homeostasis. (C) 2012 Elsevier Inc. All rights reserved.


Publication metadata

Author(s): Agius L

Publication type: Article

Publication status: Published

Journal: Biochemical Pharmacology

Year: 2013

Volume: 85

Issue: 3

Pages: 306-312

Print publication date: 26/09/2012

ISSN (print): 0006-2952

ISSN (electronic): 1873-2968

Publisher: Elsevier

URL: http://dx.doi.org/10.1016/j.bcp.2012.09.019

DOI: 10.1016/j.bcp.2012.09.019


Altmetrics

Altmetrics provided by Altmetric


Actions

Find at Newcastle University icon    Link to this publication


Share