Casper Soendenbroe1,2, Mette F Heisterberg1, Peter Schjerling1,2, Anders Karlsen1,2,3, Michael Kjaer1,2, Jesper L Andersen1,2, Abigail L Mackey1,3. 1. Institute of Sports Medicine Copenhagen, Department of Orthopaedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark. 2. Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. 3. Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Abstract
INTRODUCTION: Muscle fiber denervation increases with age, yet studies at the tissue level are sparse due to the challenging nature of establishing the relative role of regeneration and denervation. METHODS: Muscle biopsies were obtained from the vastus lateralis of 70 healthy men (aged 72 ± 6 years; range, 65-94). Messenger RNA (mRNA) levels of acetylcholine receptors (AchR) were measured, and sections were stained for embryonic myosin, neonatal myosin (MHCn ), and neural cell adhesion molecule (NCAM). RESULTS: Embryonic myosin+ fibers were rare, while MHCn + and NCAM+ fibers were observed in all samples. Age (range, 65-94 years) was negatively associated with AchRγ mRNA. DISCUSSION: Muscle from healthy older individuals expressed developmental myosins to varying degrees but more than has been previously reported for young individuals. Along with the AchR correlations, we propose that these findings support the presence of neuromuscular junction destabilization, denervation, and reinnervation in aging human skeletal muscle.
INTRODUCTION: Muscle fiber denervation increases with age, yet studies at the tissue level are sparse due to the challenging nature of establishing the relative role of regeneration and denervation. METHODS: Muscle biopsies were obtained from the vastus lateralis of 70 healthy men (aged 72 ± 6 years; range, 65-94). Messenger RNA (mRNA) levels of acetylcholine receptors (AchR) were measured, and sections were stained for embryonic myosin, neonatal myosin (MHCn ), and neural cell adhesion molecule (NCAM). RESULTS:Embryonic myosin+ fibers were rare, while MHCn + and NCAM+ fibers were observed in all samples. Age (range, 65-94 years) was negatively associated with AchRγ mRNA. DISCUSSION: Muscle from healthy older individuals expressed developmental myosins to varying degrees but more than has been previously reported for young individuals. Along with the AchR correlations, we propose that these findings support the presence of neuromuscular junction destabilization, denervation, and reinnervation in aging human skeletal muscle.
Authors: Zhengyuan Bao; Can Cui; Simon Kwoon-Ho Chow; Ling Qin; Ronald Man Yeung Wong; Wing-Hoi Cheung Journal: Front Aging Neurosci Date: 2020-12-10 Impact factor: 5.750
Authors: Jonathan Iain Quinlan; Martino Vladimiro Franchi; Nima Gharahdaghi; Francesca Badiali; Susan Francis; Andrew Hale; Bethan Eileen Phillips; Nathaniel Szewczyk; Paul Leonard Greenhaff; Kenneth Smith; Constantinos Maganaris; Phillip James Atherton; Marco Vincenzo Narici Journal: Geroscience Date: 2021-07-01 Impact factor: 7.713
Authors: Casper Soendenbroe; Christopher L Dahl; Christopher Meulengracht; Michal Tamáš; Rene B Svensson; Peter Schjerling; Michael Kjaer; Jesper L Andersen; Abigail L Mackey Journal: J Physiol Date: 2022-03-16 Impact factor: 6.228
Authors: Casper Soendenbroe; Cecilie J L Bechshøft; Mette F Heisterberg; Simon M Jensen; Emma Bomme; Peter Schjerling; Anders Karlsen; Michael Kjaer; Jesper L Andersen; Abigail L Mackey Journal: Cells Date: 2020-04-06 Impact factor: 6.600