IL-6 impairs myogenic differentiation by downmodulation of p90RSK/eEF2 and mTOR/p70S6K axes, without affecting AKT activity

Biomed Res Int. 2014:2014:206026. doi: 10.1155/2014/206026. Epub 2014 May 21.

Abstract

IL-6 is a multifaceted pleiotropic cytokine, which is produced by a variety of cell types and targets different cells and tissues. In physiological conditions, IL-6 can be locally and transiently produced by skeletal muscle and plays an important role in muscle homeostasis. Circulating IL-6 levels are normally very low or undetectable but are dramatically increased in several pathologic conditions. In this study, we aimed to define the potential molecular mechanisms underlying the effects of IL-6 on myogenic program. We explored the molecular mechanisms through which exogenous IL-6, or the conditioned medium from the murine C-26 adenocarcinoma cells (a cellular model that secretes high levels of IL-6 and induces cancer cachexia in mice), interferes with the myogenic program. Our study revealed that IL-6 induces the activation of the Stat3 signaling and promotes the downmodulation of the p90RSK/eEF2 and mTOR/p70S6K axes, while it does not affect the activation of AKT. We thus identified potential molecular mediators of the inhibitory effects of IL-6 on myogenic program.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation / physiology*
  • Cell Line, Tumor
  • Eukaryotic Initiation Factor-2 / metabolism*
  • Interleukin-6 / metabolism*
  • Mice
  • Muscle Development / physiology*
  • Muscle Fibers, Skeletal / cytology
  • Muscle Fibers, Skeletal / metabolism*
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Ribosomal Protein S6 Kinases, 70-kDa / metabolism*
  • Ribosomal Protein S6 Kinases, 90-kDa / metabolism*
  • STAT3 Transcription Factor / metabolism
  • Signal Transduction / physiology
  • TOR Serine-Threonine Kinases / metabolism*

Substances

  • Eukaryotic Initiation Factor-2
  • Interleukin-6
  • STAT3 Transcription Factor
  • Stat3 protein, mouse
  • mTOR protein, mouse
  • Proto-Oncogene Proteins c-akt
  • Ribosomal Protein S6 Kinases, 70-kDa
  • Ribosomal Protein S6 Kinases, 90-kDa
  • TOR Serine-Threonine Kinases
  • ribosomal protein S6 kinase, 90kDa, polypeptide 3