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Exercise-induced activation of STAT3 signaling is increased with age

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journal contribution
posted on 2008-08-01, 00:00 authored by M Trenerry, K Carey, Alister WardAlister Ward, M Farnfield, David Cameron-Smith
Activation of the transcription factor signal transducers and activators of transcription (STAT) 3 is common to many inflammatory cytokines and growth factors, with recent evidence of involvement in skeletal muscle regeneration. The purpose of this study was to determine whether STAT3 signaling activation is regulated differentially, at rest and following intense resistance exercise, in aged human skeletal muscle. Skeletal muscle biopsies were harvested from healthy younger (n = 11, 20.4 ± 0.8 years) and older men (n = 10, 67.4 ± 1.3 years) under resting conditions and 2 h after the completion of resistance exercise. No differences were evident at rest, whereas the phosphorylation of STAT3 was significantly increased in old (23-fold) compared to young (5-fold) subjects after exercise. This correlated with significantly higher induction of the STAT3 target genes including; interleukin-6 (IL-6), JUNB, c-MYC, and suppressor of cytokine signaling (SOCS) 3 mRNA in older subjects following exercise. Despite increased SOCS3 mRNA, cellular protein abundance was suppressed. SOCS3 protein is an important negative regulator of STAT3 activation and cytokine signaling. Thus, in aged human muscle, elevated responsiveness of the STAT3 signaling pathway and suppressed SOCS3 protein are evident following resistance exercise. These data suggest that enhanced STAT3 signaling responsiveness to proinflammatory factors may impact on mechanisms of muscle repair and regeneration.

History

Journal

Rejuvenation research

Volume

11

Issue

4

Pagination

717 - 724

Publisher

Mary Ann Liebert Publishers

Location

New Rochelle, N.Y.

ISSN

1549-1684

eISSN

1557-8577

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2008, Mary Ann Liebert Publishers