PMID- 37410905
OWN - NLM
STAT- MEDLINE
DCOM- 20230728
LR  - 20230728
IS  - 1522-1601 (Electronic)
IS  - 0161-7567 (Linking)
VI  - 135
IP  - 2
DP  - 2023 Aug 1
TI  - The importance of serial sarcomere addition for muscle function and the impact of 
      aging.
PG  - 375-393
LID - 10.1152/japplphysiol.00205.2023 [doi]
AB  - During natural aging, skeletal muscle experiences impairments in mechanical 
      performance due, in part, to changes in muscle architecture and size, notably 
      with a loss of muscle cross-sectional area (CSA). Another important factor that 
      has received less attention is the shortening of fascicle length (FL), 
      potentially reflective of a decrease in serial sarcomere number (SSN). 
      Interventions that promote the growth of new serial sarcomeres, such as chronic 
      stretching and eccentric-biased resistance training, have been suggested as 
      potential ways to mitigate age-related impairments in muscle function. Although 
      current research suggests it is possible to stimulate serial sarcomerogenesis in 
      muscle in old age, the magnitude of sarcomerogenesis may be less than in young 
      muscle. This blunted effect may be partly due to age-related impairments in the 
      pathways regulating mechanotransduction, muscle gene expression, and protein 
      synthesis, as some have been implicated in SSN adaptation. The purpose of this 
      review was to investigate the impact of aging on the ability for serial 
      sarcomerogenesis and elucidate the molecular pathways that may limit serial 
      sarcomerogenesis in old age. Age-related changes in mechanistic target of 
      rapamycin (mTOR), insulin-like growth factor 1 (IGF-1), myostatin, and serum 
      response factor signaling, muscle ring finger protein (MuRFs), and satellite 
      cells may hinder serial sarcomerogenesis. In addition, our current understanding 
      of SSN in older humans is limited by assumptions based on ultrasound-derived 
      fascicle length. Future research should explore the effects of age-related 
      changes in the identified pathways on the ability to stimulate serial 
      sarcomerogenesis, and better estimate SSN adaptations to gain a deeper 
      understanding of the adaptability of muscle in old age.
FAU - Hinks, Avery
AU  - Hinks A
AUID- ORCID: 0000-0002-1809-1006
AD  - Department of Human Health and Nutritional Sciences, College of Biological 
      Sciences, University of Guelph, Guelph, Ontario, Canada.
FAU - Hawke, Thomas J
AU  - Hawke TJ
AUID- ORCID: 0000-0003-4974-4820
AD  - Department of Pathology and Molecular Medicine, McMaster University, Hamilton, 
      Ontario, Canada.
FAU - Franchi, Martino V
AU  - Franchi MV
AUID- ORCID: 0000-0003-3165-4536
AD  - Department of Biomedical Sciences, Neuromuscular Physiology Laboratory, 
      University of Padua, Padua, Italy.
FAU - Power, Geoffrey A
AU  - Power GA
AUID- ORCID: 0000-0003-2604-0740
AD  - Department of Human Health and Nutritional Sciences, College of Biological 
      Sciences, University of Guelph, Guelph, Ontario, Canada.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Review
DEP - 20230706
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
SB  - IM
MH  - Humans
MH  - Aged
MH  - *Sarcomeres/physiology
MH  - Mechanotransduction, Cellular
MH  - Muscle, Skeletal/physiology
MH  - Aging
MH  - *Musculoskeletal Physiological Phenomena
OTO - NOTNLM
OT  - aging
OT  - focal adhesion kinase
OT  - force-length relationship
OT  - titin
OT  - ultrasound
EDAT- 2023/07/06 19:12
MHDA- 2023/07/28 06:42
CRDT- 2023/07/06 15:13
PHST- 2023/07/28 06:42 [medline]
PHST- 2023/07/06 19:12 [pubmed]
PHST- 2023/07/06 15:13 [entrez]
AID - 10.1152/japplphysiol.00205.2023 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 2023 Aug 1;135(2):375-393. doi: 
      10.1152/japplphysiol.00205.2023. Epub 2023 Jul 6.