Mechanical loading stimulates hypertrophy in tissue-engineered skeletal muscle: Molecular and phenotypic responses.

Autor: Aguilar-Agon KW; School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom., Capel AJ; School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom., Martin NRW; School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom., Player DJ; Division of Surgery, University College London, London, United Kingdom., Lewis MP; School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom.
Jazyk: angličtina
Zdroj: Journal of cellular physiology [J Cell Physiol] 2019 Dec; Vol. 234 (12), pp. 23547-23558. Date of Electronic Publication: 2019 Jun 10.
DOI: 10.1002/jcp.28923
Abstrakt: Mechanical loading of skeletal muscle results in molecular and phenotypic adaptations typified by enhanced muscle size. Studies on humans are limited by the need for repeated sampling, and studies on animals have methodological and ethical limitations. In this investigation, three-dimensional skeletal muscle was tissue-engineered utilizing the murine cell line C2C12, which bears resemblance to native tissue and benefits from the advantages of conventional in vitro experiments. The work aimed to determine if mechanical loading induced an anabolic hypertrophic response, akin to that described in vivo after mechanical loading in the form of resistance exercise. Specifically, we temporally investigated candidate gene expression and Akt-mechanistic target of rapamycin 1 signalling along with myotube growth and tissue function. Mechanical loading (construct length increase of 15%) significantly increased insulin-like growth factor-1 and MMP-2 messenger RNA expression 21 hr after overload, and the levels of the atrophic gene MAFbx were significantly downregulated 45 hr after mechanical overload. In addition, p70S6 kinase and 4EBP-1 phosphorylation were upregulated immediately after mechanical overload. Maximal contractile force was augmented 45 hr after load with a 265% increase in force, alongside significant hypertrophy of the myotubes within the engineered muscle. Overall, mechanical loading of tissue-engineered skeletal muscle induced hypertrophy and improved force production.
(© 2019 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.)
Databáze: MEDLINE
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