Exercise normalises overexpression of TNF-alpha in knockout mice

Biochem Biophys Res Commun. 2004 Aug 13;321(1):179-82. doi: 10.1016/j.bbrc.2004.06.129.

Abstract

TNF-alpha is linked with insulin resistance, as greater amounts of TNF are detected in muscle and adipose tissue in glycemically challenged people and TNF-alpha inhibits insulin receptor signalling. However, what modulates this overexpression of TNF-alpha is currently unknown. We examined the effect of 1 h exercise on overexpression of the TNF-alpha gene in TNF receptor 1 and 2 knockout mice. IL-6 knockout mice were included to elucidate the importance of IL-6 in regulating TNF-alpha in response to exercise. TNF-alpha gene expression was over-expressed in muscle in both TNFR knockout models. TNF-alpha overexpression returned to normal levels after exercise in the TNF-alpha receptor knockout models. In IL-6 knockout mice, a modest decrease in TNF-alpha was also observed. These data suggest that TNF-alpha-induced insulin resistance can be regulated by a single exercise bout by normalising TNF-alpha expression. This exercise effect can be mediated via IL-6, but also an IL-6 independent mechanism seems to exist.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / physiology
  • Animals
  • Antigens, CD / genetics
  • Antigens, CD / physiology*
  • Female
  • Insulin Resistance / genetics
  • Insulin Resistance / physiology
  • Interleukin-6 / deficiency
  • Interleukin-6 / genetics
  • Interleukin-6 / physiology
  • Male
  • Mice
  • Mice, Knockout
  • Muscle, Skeletal / physiology
  • Physical Conditioning, Animal / physiology*
  • RNA, Messenger / genetics
  • Receptors, Tumor Necrosis Factor / deficiency
  • Receptors, Tumor Necrosis Factor / genetics
  • Receptors, Tumor Necrosis Factor / physiology*
  • Receptors, Tumor Necrosis Factor, Type I
  • Receptors, Tumor Necrosis Factor, Type II
  • Tumor Necrosis Factor-alpha / genetics*

Substances

  • Antigens, CD
  • Interleukin-6
  • RNA, Messenger
  • Receptors, Tumor Necrosis Factor
  • Receptors, Tumor Necrosis Factor, Type I
  • Receptors, Tumor Necrosis Factor, Type II
  • Tumor Necrosis Factor-alpha