The use of adipose tissue-conditioned media to demonstrate the differential effects of fat depots on insulin-stimulated glucose uptake in a skeletal muscle cell line

Yan Y. Lam, Alena Janovská, Andrew J. McAinch, Damien P. Belobrajdic, George Hatzinikolas, Philip Game, Gary A. Wittert

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

We aimed to study the depot-specific effect of adipose tissue on insulin sensitivity of skeletal muscle in vitro. Adipose tissue-conditioned medium (CM) was generated from visceral and subcutaneous fat from obese subjects. CM from visceral as compared to subcutaneous fat had higher concentrations of interleukin (IL)-6 (15-fold; P < 0.05) and IL-8 (8-fold; P < 0.05). CM from visceral fat (1:128 dilution) reduced insulin-stimulated glucose uptake in L6 myotubes by 19% (P < 0.05), an effect mediated by a nuclear factor kappa B (NFκB)/mammalian target of rapamycin complex 1 (mTORC1)-dependent pathway and partially reversed by neutralizing IL-6. IL-6 at a concentration comparable to that in CM from visceral fat reduced insulin-stimulated glucose uptake by 53% (P < 0.05), an effect abolished by inhibiting NFκB or mTORC1. We demonstrated the utility of the CM-myotube system and identified IL-6 as a major cytokine mediating visceral fat-induced muscle insulin resistance.

LanguageEnglish
JournalObesity Research and Clinical Practice
Volume5
Issue number1
DOIs
Publication statusPublished - 1 Jan 2011

Keywords

  • Adipokines
  • Insulin resistance
  • Skeletal muscle

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Nutrition and Dietetics

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