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Assessment of the Metabolic Effects of Isocaloric 2:1 Intermittent Fasting in Mice
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Diminished AMPK signaling response to fasting in thioredoxin-interacting protein knockout mice

Allen M Andres1, Eric P Ratliff, Sowbarnika Sachithanantham

  • 1Department of Biology, BioScience Center, San Diego State University, San Diego, CA 92182, USA.

FEBS Letters
|March 29, 2011
PubMed

Insights

Thioredoxin-interacting protein (Txnip) knockout mice show impaired fasting responses, particularly in oxidative muscles. Txnip deficiency affects AMP-activated protein kinase and glycogen levels, highlighting its metabolic role.

Area of Science:

  • Metabolic regulation
  • Muscle physiology
  • Molecular biology

Background:

  • Thioredoxin-interacting protein (Txnip) is implicated in cellular metabolism.
  • Txnip knockout (TKO) mice display altered physiological responses.
  • Fasting triggers significant metabolic shifts in mammals.

Purpose of the Study:

  • To investigate the metabolic role of Txnip during fasting.
  • To compare the impact of Txnip deficiency on oxidative versus glycolytic muscles.

Main Methods:

  • Assessment of adenine monophosphate-activated protein kinase (AMPK) activation.
  • Measurement of cellular AMP levels.
  • Quantification of muscle glycogen content in fasting TKO mice and controls.

Main Results:

  • AMPK activation and cellular AMP levels were reduced in the heart and soleus (oxidative) muscle of fasting TKO mice.
  • Glycogen content was elevated in oxidative muscles of fasting TKO mice.
  • These metabolic alterations were not observed in the gastrocnemius (glycolytic) muscle.

Conclusions:

  • Txnip deficiency significantly impacts the metabolic adaptation to fasting in oxidative muscles.
  • Txnip plays a crucial role in regulating energy metabolism, particularly in oxidative tissues.
  • These findings provide novel insights into the differential metabolic functions of Txnip in various muscle types.

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