ePrints

Role of glycogen content in insulin resistance in human muscle cells

Lookup NU author(s): Dr Gary Litherland, Dr Nick Morris, Professor Mark Walker, Emeritus Professor Steve Yeaman

Downloads

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

Abstract

We have used primary human muscle cell cultures to investigate the role of glycogen loading in cellular insulin resistance. Insulin pre-treatment for 2 h markedly impaired insulin signaling, as assessed by protein kinase B (PKB) phosphorylation. In contrast, insulin-dependent glycogen synthesis, glycogen synthase (GS) activation, and GS sites 3 de-phosphorylation were impaired only after 5 h of insulin pre-treatment, whereas 2-deoxyglucose transport was only decreased after 18 h pre-treatment. Insulin-resistant glycogen synthesis was associated closely with maximal glycogen loading. Both glucose limitation and 5-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR) treatment during insulin pre-treatment curtailed glycogen accumulation, and concomitantly restored insulin-sensitive glycogen synthesis and GS activation, although GS de-phosphorylation and PKB phosphorylation remained impaired. Conversely, glycogen super-compensation diminished insulin-sensitive glycogen synthesis and GS activity. Insulin acutely promoted GS translocation to particulate subcellular fractions; this was abolished by insulin pre-treatment, as was GS dephosphorylation therein. Limiting glycogen accumulation during insulin pre-treatment re-instated GS dephosphorylation in particulate fractions, whereas glycogen super-compensation prevented insulin-stimulated GS translocation and dephosphorylation. Our data suggest that diminished insulin signaling alone is insufficient to impair glucose disposal, and indicate a role for glycogen accumulation in inducing insulin resistance in human muscle cells. © 2006 Wiley-Liss, Inc.

Publication metadata

Author(s): Litherland GJ, Morris NJ, Walker M, Yeaman SJ

Publication type: Article

Publication status: Published

Journal: Journal of Cellular Physiology

Year: 2007

Volume: 211

Issue: 2

Pages: 344-352

ISSN (print): 0021-9541

ISSN (electronic): 1097-4652

Publisher: John Wiley & Sons, Inc.

URL: http://dx.doi.org/10.1002/jcp.20942

DOI: 10.1002/jcp.20942

PubMed id: 17167773

Altmetrics

Funding

Share