Preserved capacity for satellite cell proliferation, regeneration, and hypertrophy in the skeletal muscle of healthy elderly men

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

  • Anders Karlsen
  • Casper Soendenbroe
  • Nikolaj M. Malmgaard‐clausen
  • Frederik Wagener
  • Casper Emil Moeller
  • Zouhir Senhaji
  • Kristine Damberg
  • Jesper Løvind Andersen
  • Peter Schjerling
  • Kjær, Michael
  • Mackey, Abigail
Blunted muscle hypertrophy and impaired regeneration with aging have been partly attributed to satellite cell (SC) dysfunction. However, true muscle regeneration has not yet been studied in elderly individuals. To investigate this, muscle injury was induced by 200 electrically stimulated (ES) eccentric contractions of the vastus lateralis (VL) of one leg in seven young (20-31 years) and 19 elderly men (60-73 years). This was followed by 13 weeks of resistance training (RT) for both legs to investigate the capacity for hypertrophy. Muscle biopsies were collected Pre- and Post-RT, and 9 days after ES, for immunohistochemistry and RT-PCR. Hypertrophy was assessed by MRI, DEXA, and immunohistochemistry. Overall, surprisingly comparable responses were observed between the young and elderly. Nine days after ES, Pax7+ SC number had doubled (P < .05), alongside necrosis and substantial changes in expression of genes related to matrix, myogenesis, and innervation (P < .05). Post-RT, VL cross-sectional area had increased in both legs (15%, P < .05) and SCs/type II fiber had increased 2-4 times more with ES+RT vs RT alone (P < .001). Together these novel findings demonstrate "youthful" regeneration and hypertrophy responses in human elderly muscle. Furthermore, boosting SC availability in healthy elderly men does not enhance the subsequent muscle hypertrophy response to RT.
OriginalsprogEngelsk
TidsskriftThe FASEB Journal
Vol/bind34
Udgave nummer5
Sider (fra-til)6418-6436
ISSN0892-6638
DOI
StatusUdgivet - 2020

ID: 237525036