Skeletal muscle fibers count on nuclear numbers for growth

Prasad, Vikram; Millay, Douglas P.

doi:10.1016/j.semcdb.2021.04.015

Cited by 17 publications

(15 citation statements)

References 107 publications

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“…Because age dependence was not the main focus of this study, we pointed our attention on 2- to 3-month-old mice. Moreover, the necessity of competent fusing SCs to have the correct muscle hypertrophy in young mice has been clearly demonstrated using genetic mouse models in which SCs are unable to fuse ( Prasad and Millay, 2021 ). For instance, SC deletion of Myomaker , a muscle-specific membrane protein necessary for fusion of muscle progenitors, compromised muscle hypertrophic response ( Goh and Millay, 2017 ).…”

Section: Discussionmentioning

confidence: 99%

RhoA within myofibers controls satellite cell microenvironment to allow hypertrophic growth

et al. 2022

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Adult skeletal muscle is a plastic tissue that can adapt its size to workload. Here, we show that RhoA within myofibers is needed for overload-induced hypertrophy by controlling satellite cell (SC) fusion to the growing myofibers without affecting protein synthesis. At the molecular level, we demonstrate that RhoA controls in a cell autonomous manner Erk1/2 activation and the expressions of extracellular matrix (ECM) regulators such as Mmp9/Mmp13/Adam8 and macrophage chemo-attractants such as Ccl3/Cx3cl1. Their decreased expression in RhoA mutants is associated with ECM and fibrillar collagen disorganization and lower macrophage infiltration. Moreover, matrix metalloproteinases inhibition and macrophage depletion in controls phenocopied the altered growth of RhoA mutants while having no effect in mutants showing that their action is RhoA-dependent. These findings unravel the implication of RhoA within myofibers, in the building of a permissive microenvironment for muscle hypertrophic growth and for SC accretion through ECM remodeling and inflammatory cell recruitment.

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Section: Discussionmentioning

confidence: 99%

RhoA within myofibers controls satellite cell microenvironment to allow hypertrophic growth

et al. 2022

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“…Conversely, studies show that muscle nuclei are lost during periods of muscle atrophy (Snijders et al 2020;Viggars et al 2022). However, recent evidence demonstrates that myonuclear transcriptional output can be modulated to accommodate variable myonuclear domains (Kirby et al 2016), and our understanding of myonuclear domains is still evolving (Prasad & Millay, 2021). Nevertheless, the findings showing that myonuclei could be lost in response to myofibre atrophy has been challenged in recent years (Eftestøl et al 2020;Schwartz, 2019).…”

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confidence: 99%

Cross Talk proposal: Myonuclei are lost with ageing and atrophy

Kirby

Dupont‐Versteegden

2022

The Journal of Physiology

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support-information-section). The myonuclear domain hypothesisAdult muscle retains a population of muscle stem cells, termed satellite cells, that can be activated in response to muscle injury, but also participate in muscle adaptation and muscle homeostasis (Chen et al. 2020). The multinucleated nature of myofibres, coupled with the ability to add myonuclei through satellite cell fusion, led to the 'myonuclear domain theory' , which states that each myonucleus is responsible for the transcriptional output for a fixed amount of cytoplasm. When a muscle fibre undergoes hypertrophy, new nuclei can be

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“…By contrast, mature mouse muscle fibers have a significant myonuclear transcriptional reserve capacity during hypertrophy 21,89,172 and can activate pro‐hypertrophic signaling in the absence of satellite cell fusion, 21 an observation supported by human and rodent studies 46,173–177 . On balance, it has been put forth that the larger the muscle fiber, the smaller the transcriptional reserve 178 . This may be most relevant in the context of early developmental growth since it seems that adult muscle fibers of all myosin types and size can grow during prolonged loading without myonuclear addition, 32,64 so more work is needed to substantiate this concept.…”

Section: Recent Resultsmentioning

confidence: 99%

“… 46 , 173 , 174 , 175 , 176 , 177 On balance, it has been put forth that the larger the muscle fiber, the smaller the transcriptional reserve. 178 This may be most relevant in the context of early developmental growth since it seems that adult muscle fibers of all myosin types and size can grow during prolonged loading without myonuclear addition, 32 , 64 so more work is needed to substantiate this concept. Differing ages of mice used for experiments (immature versus adult) could in part explain why some studies report necessity for satellite cell fusion during hypertrophy while others do not.…”

Section: Recent Resultsmentioning

confidence: 99%