Reduced AMPK-ACC and mTOR signaling in muscle from older men, and effect of resistance exercise.

M. Li, L.B. Verdijk, K. Sakamoto, B. Ely, L.J.C. van Loon, N. Musi

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

AMP-activated protein kinase (AMPK) is a key energy-sensitive enzyme that controls numerous metabolic and cellular processes. Mammalian target of rapamycin (mTOR) is another energy/nutrient-sensitive kinase that controls protein synthesis and cell growth. In this study we determined whether older versus younger men have alterations in the AMPK and mTOR pathways in skeletal muscle, and examined the effect of a long term resistance type exercise training program on these signaling intermediaries. Older men had decreased AMPKalpha2 activity and lower phosphorylation of AMPK and its downstream signaling substrate acetyl-CoA carboxylase (ACC). mTOR phosphylation also was reduced in muscle from older men. Exercise training increased AMPKalpha1 activity in older men, however, AMPKalpha2 activity, and the phosphorylation of AMPK, ACC and mTOR, were not affected. In conclusion, older men have alterations in the AMPK-ACC and mTOR pathways in muscle. In addition, prolonged resistance type exercise training induces an isoform-selective up regulation of AMPK activity.
Original languageEnglish
Pages (from-to)655-664
Number of pages10
JournalMechanisms of Ageing and Development
Volume133
Issue number11-12
DOIs
Publication statusPublished - 1 Jan 2012

Keywords

  • Aging
  • Skeletal muscle
  • AMPK
  • mTOR
  • Resistance exercise
  • ACTIVATED PROTEIN-KINASE
  • HUMAN SKELETAL-MUSCLE
  • GLUCOSE-UPTAKE
  • ELDERLY-MEN
  • MAMMALIAN TARGET
  • DOSE-RESPONSE
  • CELL-GROWTH
  • AMINO-ACID
  • YOUNG
  • HYPERTROPHY

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