Long-term high-level exercise promotes muscle reinnervation with age

Authors: S. Zampieri(1,2), L. Pietrangelo(3), S. Loefler(1), H. Fruhmann(1), M. Vogelauer(4), S. Burggraf(19), A. Pond(5), M. Grim-Stieger(4), J. Cvecka(6), M. Sedliak(6), V. Tirpáková(6), W. Mayr(7), N. Sarabon(8), K. Rossini(1,2), L. Barberi(9), M. De Rossi(9), V. Romanello(2,10), S. Boncompagni(3), A. Musarò(9), M. Sandri(2,10), F. Protasi(3), U. Carraro(2) and H. Kern(1,4)

Source: J Gerontol A Biol Sci Med Sci. 2015 Feb;70(2):163-73. doi: 10.1093/gerona/glu006. Epub 2014 Feb 18.

Keywords: Calcium release unit, Force, Human skeletal muscle, Physical exercise, Signaling pathways

Abstract:

Aging is usually accompanied by a significant reduction in muscle mass and force. To determine the relative contribution of inactivity and aging per se to this decay, we compared muscle function and structure in (a) male participants belonging to a group of well-trained seniors (average of 70 years) who exercised regularly in their previous 30 years and (b) age-matched healthy sedentary seniors with (c) active young men (average of 27 years). The results collected show that relative to their sedentary cohorts, muscle from senior sportsmen have: (a) greater maximal isometric force and function, (b) better preserved fiber morphology and ultrastructure of intracellular organelles involved in Ca2+ handling and ATP production, (c) preserved muscle fibers size resulting from fiber rescue by reinnervation, and (d) lowered expression of genes related to autophagy and reactive oxygen species detoxification. All together, our results indicate that: (a) skeletal muscle of senior sportsmen is actually more similar to that of adults than to that of age-matched sedentaries and (b) signaling pathways controlling muscle mass and metabolism are differently modulated in senior sportsmen to guarantee maintenance of skeletal muscle structure, function, bioenergetic characteristics, and phenotype. Thus, regular physical activity is a good strategy to attenuate age-related general decay of muscle structure and function (ClinicalTrials.gov: NCT01679977).

Affiliations:

1 Ludwig Boltzmann Institute of Electrical Stimulation and Physical Rehabilitation, Vienna, Austria
2 Department of Biomedical Sciences, University of Padova, Italy
3 CeSI – Center for Research on Aging – Department of Neuroscience, Imaging and Clinical Sciences, University G. d’Annunzio of Chieti, Italy
4 Department of Physical Medicine and Rehabilitation, Wilhelminenspital, Vienna, Austria
5 Anatomy Department, Southern Illinois University School of Medicine, Carbondale
6 Faculty of Physical Education and Sport, Comenius University, Bratislava, Slovakia
7 Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
8 University of Primorska, Science and Research Centre, Institute for Kinesilogical Research, Koper, Slovenia
9 Institute Pasteur Cenci-Bolognetti, DAHFMO-Unit of Histology and Medical Embryology, IIM, Sapienza University of Rome, Rome, Italy
10 Venetian Institute of Molecular Medicine, Dulbecco Telethon Institute, Padova, Italy