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JNK activation in TA and EDL muscle is load-dependent in rats receiving identical excitation patterns
As the excitation–contraction coupling is inseparable during voluntary exercise, the relative contribution of the mechanical and neural input on hypertrophy-related molecular signalling is still poorly understood. Herein, we use a rat in-vivo strength exercise model with an electrically-induced stan...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8361015/ https://www.ncbi.nlm.nih.gov/pubmed/34385505 http://dx.doi.org/10.1038/s41598-021-94930-x |
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author | Eftestøl, Einar Franchi, Martino V. Kasper, Stephanie Flück, Martin |
author_facet | Eftestøl, Einar Franchi, Martino V. Kasper, Stephanie Flück, Martin |
author_sort | Eftestøl, Einar |
collection | PubMed |
description | As the excitation–contraction coupling is inseparable during voluntary exercise, the relative contribution of the mechanical and neural input on hypertrophy-related molecular signalling is still poorly understood. Herein, we use a rat in-vivo strength exercise model with an electrically-induced standardized excitation pattern, previously shown to induce a load-dependent increase in myonuclear number and hypertrophy, to study acute effects of load on molecular signalling. We assessed protein abundance and specific phosphorylation of the four protein kinases FAK, mTOR, p70S6K and JNK after 2, 10 and 28 min of a low- or high-load contraction, in order to assess the effects of load, exercise duration and muscle-type on their response to exercise. Specific phosphorylation of mTOR, p70S6K and JNK was increased after 28 min of exercise under the low- and high-load protocol. Elevated phosphorylation of mTOR and JNK was detectable already after 2 and 10 min of exercise, respectively, but greatest after 28 min of exercise, and JNK phosphorylation was highly load-dependent. The abundance of all four kinases was higher in TA compared to EDL muscle, p70S6K abundance was increased after exercise in a load-independent manner, and FAK and JNK abundance was reduced after 28 min of exercise in both the exercised and control muscles. In conclusion, the current study shows that JNK activation after a single resistance exercise is load-specific, resembling the previously reported degree of myonuclear accrual and muscle hypertrophy with repetition of the exercise stimulus. |
format | Online Article Text |
id | pubmed-8361015 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-83610152021-08-17 JNK activation in TA and EDL muscle is load-dependent in rats receiving identical excitation patterns Eftestøl, Einar Franchi, Martino V. Kasper, Stephanie Flück, Martin Sci Rep Article As the excitation–contraction coupling is inseparable during voluntary exercise, the relative contribution of the mechanical and neural input on hypertrophy-related molecular signalling is still poorly understood. Herein, we use a rat in-vivo strength exercise model with an electrically-induced standardized excitation pattern, previously shown to induce a load-dependent increase in myonuclear number and hypertrophy, to study acute effects of load on molecular signalling. We assessed protein abundance and specific phosphorylation of the four protein kinases FAK, mTOR, p70S6K and JNK after 2, 10 and 28 min of a low- or high-load contraction, in order to assess the effects of load, exercise duration and muscle-type on their response to exercise. Specific phosphorylation of mTOR, p70S6K and JNK was increased after 28 min of exercise under the low- and high-load protocol. Elevated phosphorylation of mTOR and JNK was detectable already after 2 and 10 min of exercise, respectively, but greatest after 28 min of exercise, and JNK phosphorylation was highly load-dependent. The abundance of all four kinases was higher in TA compared to EDL muscle, p70S6K abundance was increased after exercise in a load-independent manner, and FAK and JNK abundance was reduced after 28 min of exercise in both the exercised and control muscles. In conclusion, the current study shows that JNK activation after a single resistance exercise is load-specific, resembling the previously reported degree of myonuclear accrual and muscle hypertrophy with repetition of the exercise stimulus. Nature Publishing Group UK 2021-08-12 /pmc/articles/PMC8361015/ /pubmed/34385505 http://dx.doi.org/10.1038/s41598-021-94930-x Text en © The Author(s) 2021 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Article Eftestøl, Einar Franchi, Martino V. Kasper, Stephanie Flück, Martin JNK activation in TA and EDL muscle is load-dependent in rats receiving identical excitation patterns |
title | JNK activation in TA and EDL muscle is load-dependent in rats receiving identical excitation patterns |
title_full | JNK activation in TA and EDL muscle is load-dependent in rats receiving identical excitation patterns |
title_fullStr | JNK activation in TA and EDL muscle is load-dependent in rats receiving identical excitation patterns |
title_full_unstemmed | JNK activation in TA and EDL muscle is load-dependent in rats receiving identical excitation patterns |
title_short | JNK activation in TA and EDL muscle is load-dependent in rats receiving identical excitation patterns |
title_sort | jnk activation in ta and edl muscle is load-dependent in rats receiving identical excitation patterns |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8361015/ https://www.ncbi.nlm.nih.gov/pubmed/34385505 http://dx.doi.org/10.1038/s41598-021-94930-x |
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