TY - JOUR
T1 - Preserved capacity for satellite cell proliferation, regeneration, and hypertrophy in the skeletal muscle of healthy elderly men
AU - Karlsen, Anders
AU - Soendenbroe, Casper
AU - Malmgaard‐clausen, Nikolaj M.
AU - Wagener, Frederik
AU - Moeller, Casper Emil
AU - Senhaji, Zouhir
AU - Damberg, Kristine
AU - Andersen, Jesper Løvind
AU - Schjerling, Peter
AU - Kjaer, Michael
AU - Mackey, Abigail L.
PY - 2020
Y1 - 2020
N2 - 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.
AB - 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.
U2 - 10.1096/fj.202000196R
DO - 10.1096/fj.202000196R
M3 - Journal article
C2 - 32167202
SN - 0892-6638
VL - 34
SP - 6418
EP - 6436
JO - The FASEB Journal
JF - The FASEB Journal
IS - 5
ER -