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Insulin resistance is a cellular antioxidant defense mechanism

Abstract

We know a great deal about the cellular response to starvation via AMPK, but less is known about the reaction to nutrient excess. Insulin resistance may be an appropriate response to nutrient excess, but the cellular sensors that link these parameters remain poorly defined. In the present study we provide evidence that mitochondrial superoxide production is a common feature of many different models of insulin resistance in adipocytes, myotubes, and mice. In particular, insulin resistance was rapidly reversible upon exposure to agents that act as mitochondrial uncouplers, ETC inhibitors, or mitochondrial superoxide dismutase (MnSOD) mimetics. Similar effects were observed with overexpression of mitochondrial MnSOD. Furthermore, acute induction of mitochondrial superoxide production using the complex III antagonist antimycin A caused rapid attenuation of insulin action independently of changes in the canonical PI3K/Akt pathway. These results were validated in vivo in that MnSOD transgenic mice were partially protected against HFD induced insulin resistance and MnSOD+/- mice were glucose intolerant on a standard chow diet. These data place mitochondrial superoxide at the nexus between intracellular metabolism and the control of insulin action potentially defining this as a metabolic sensor of energy excess.

Type Journal
ISBN 1091-6490 (Electronic)
Authors Hoehn, K. L.; Salmon, A. B.; Hohnen-Behrens, C.; Turner, N.; Hoy, A. J.; Maghzal, G. J.; Stocker, R.; Van Remmen, H.; Kraegen, E. W.; Cooney, G. J.; Richardson, A. R.; James, D. E.
Publisher Name PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Published Date 2009-10-20 00:00:00
Published Volume 106
Published Issue 42
Published Pages 17787-92
Status Published in-print
DOI 0902380106 [pii] 10.1073/pnas.0902380106
URL link to publisher's version http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19805130
OpenAccess link to author's accepted manuscript version https://publications.gimr.garvan.org.au/open-access/10343