These authors contributed equally to this work.
Metabolic and Steatohepatitis
Taurine-induced insulin signalling improvement of obese malnourished mice is associated with redox balance and protein phosphatases activity modulation
Version of Record online: 2 SEP 2013
© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Volume 34, Issue 5, pages 771–783, May 2014
How to Cite
Liver Int. 2014: 34: 771–783
- Issue online: 8 APR 2014
- Version of Record online: 2 SEP 2013
- Accepted manuscript online: 31 JUL 2013 02:45AM EST
- Manuscript Accepted: 24 JUL 2013
- Manuscript Received: 16 JAN 2013
- National Institute of Obesity and Diabetes
- antioxidant enzymes;
- hydrogen peroxide;
- PTEN ;
Background & Aims
Obese protein malnourished mice display liver insulin resistance and taurine (TAU) seems to attenuate this effect. The association between early-life malnutrition and hepatic redox balance in diet-induced insulin resistance is unknown. We investigated TAU supplementation effects upon liver redox state and insulin signalling in obese protein malnourished mice.
Weaned male C57BL-6 mice were fed a control (14% protein – C) or a protein-restricted diet (6% protein – R) for 6 weeks. Afterwards, mice received a high-fat diet (34% fat – HFD) for 8 weeks (CH – RH). Half of the HFD-mice were supplemented with TAU (5%) throughout the treatment (CHT – RHT). Body and tissues' weight, respiratory quotient (RQ), glucose tolerance and insulin sensitivity, hepatic oxidant and antioxidant markers and insulin cascade proteins were assessed.
Protein restriction leads to typical features whereas HFD was able to induce a catch-up growth in RH. HFD-groups showed higher energy intake and adiposity, lower energy expenditure and altered RQ. Glucose tolerance and insulin sensitivity were impaired in HFD-groups and TAU attenuated these effects. H2O2 content was increased in CHT and RHT despite no differences in antioxidant enzymes and GSH concentration. AKT and PTEN phosphorylation were significantly increased in CHT but not in RHT.
Our data provide evidence for an association between TAU-induced improved glycaemic control because of PTEN inactivation and higher AKT phosphorylation. These effects seem to be related with altered hepatic redox balance in obese mice, and this effect is impaired by protein malnutrition.