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Liver-specific deletion of insulin receptor substrate 2 does not impair hepatic glucose and lipid metabolism in mice

Citation

Simmgen, M and Knauf, C and Lopez, M and Choudhury, AI and Charalambous, M and Cantley, J and Bedford, DC and Claret, M and Iglesias, MA and Heffron, H and Cani, PD and Vidal-Puig, A and Burcelin, R and Withers, DJ, Liver-specific deletion of insulin receptor substrate 2 does not impair hepatic glucose and lipid metabolism in mice, Diabetologia: Clinical and Experimental Diabetes and Metabolism, 49, (3) pp. 552-561. ISSN 0012-186X (2006) [Refereed Article]

Copyright Statement

Copyright 2006 Springer-Verlag

DOI: doi:10.1007/s00125-005-0084-4

Abstract

AIMS/HYPOTHESIS: Hepatic insulin resistance is thought to be a critical component in the pathogenesis of type 2 diabetes but the role of intrinsic insulin signalling pathways in the regulation of hepatic metabolism remains controversial. Global gene targeting in mice and in vitro studies have suggested that IRS2 mediates the physiological effects of insulin in the liver. Reduced hepatic production of IRS2 is found in many cases of insulin resistance. To investigate the role of IRS2 in regulating liver function in vivo, we generated mice that specifically lack Irs2 in the liver (LivIrs2KO). MATERIALS AND METHODS: Hepatic insulin signalling events were examined in LivIrs2KO mice by western blotting. Glucose homeostasis and insulin sensitivity were assessed by glucose tolerance tests and hyperinsulinaemic-euglycaemic clamp studies. The effects of high-fat feeding upon glucose homeostasis were also determined. Liver function tests were performed and expression of key metabolic genes in the liver was determined by RT-PCR. RESULTS: Proximal insulin signalling events and forkhead box O1 and A2 function were normal in the liver of LivIrs2KO mice, which displayed minimal abnormalities in glucose and lipid homeostasis, hepatic gene expression and liver function. In addition, hepatic lipid homeostasis and the metabolic response to a high-fat diet did not differ between LivIrs2KO and control mice. CONCLUSIONS/INTERPRETATION: Our findings suggest that liver IRS2 signalling, surprisingly, is not required for the long-term maintenance of glucose and lipid homeostasis, and that extra-hepatic IRS2-dependent mechanisms are involved in the regulation of these processes.

Item Details

Item Type:Refereed Article
Research Division:Medical and Health Sciences
Research Group:Medical Biochemistry and Metabolomics
Research Field:Metabolic Medicine
Objective Division:Health
Objective Group:Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:Diabetes
Author:Iglesias, MA (Dr Miguel Iglesias)
ID Code:80260
Year Published:2006
Web of Science® Times Cited:22
Deposited By:Health Sciences A
Deposited On:2012-10-25
Last Modified:2013-04-10
Downloads:0

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