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TNF-alpha inhibits adult fast myosin accumulation in myotubes

Vincent T Los1, Henk P Haagsman

  • 1Division of Public Health and Food Safety, Faculty of Veterinary Medicine, Graduate School Animal Health, Utrecht University, P.O. Box 80175, 3508 TD Utrecht, The Netherlands.

Cytokine
|September 29, 2006
PubMed

Insights

Tumor necrosis factor-alpha (TNF-alpha) has a dual role in muscle cells. It can stimulate regeneration with short exposure but cause muscle wasting with prolonged exposure, explaining previous research discrepancies.

Area of Science:

  • Muscle biology
  • Cellular signaling
  • Inflammatory disease research

Background:

  • Muscle catabolism is linked to inflammatory diseases.
  • Tumor necrosis factor-alpha (TNF-alpha) is a suspected mediator of muscle catabolism.
  • Previous studies on TNF-alpha's effects on muscle cells yielded conflicting results.

Purpose of the Study:

  • To investigate the discrepancies in previous research regarding TNF-alpha's effects on muscle cells.
  • To elucidate the mechanisms behind TNF-alpha's influence on myoblast proliferation and protein synthesis.

Main Methods:

  • Utilized the C2C12 mouse cell line for experiments.
  • Exposed differentiated muscle cultures to TNF-alpha under varying serum conditions.
  • Assessed myoblast proliferation, adult fast myosin accumulation, and total cell protein.

Main Results:

  • TNF-alpha induced myoblast proliferation in differentiated cultures with low serum.
  • TNF-alpha inhibited adult fast myosin accumulation universally.
  • A proliferation-dependent increase in total cell protein was observed with TNF-alpha exposure.
  • Insulin partially masked TNF-alpha's effect on total protein but not myosin accumulation.

Conclusions:

  • Observed discrepancies in prior studies are attributable to variations in proliferation rates and myosin accumulation dynamics.
  • TNF-alpha exhibits a dual role: promoting regeneration via short-term exposure and inducing muscle wasting via prolonged exposure.

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