Stage-specific effects of Notch activation during skeletal myogenesis
- Purdue University, United States
Abstract
Skeletal myogenesis involves sequential activation, proliferation, self-renewal/differentiation and fusion of myogenic stem cells (satellite cells). Notch signaling is known to be essential for the maintenance of satellite cells, but its function in late-stage myogenesis, i.e. post-differentiation myocytes and post-fusion myotubes, is unknown. Using stage-specific Cre alleles, we uncovered distinct roles of Notch1 in mononucleated myocytes and multinucleated myotubes. Specifically, constitutive Notch1 activation dedifferentiates myocytes into Pax7+ quiescent satellite cells, leading to severe defects in muscle growth and regeneration, and postnatal lethality. By contrast, myotube-specific Notch1 activation improves the regeneration and exercise performance of aged and dystrophic muscles. Mechanistically, Notch1 activation in myotubes upregulates the expression of Notch ligands, which modulate Notch signaling in the adjacent satellite cells to enhance their regenerative capacity. These results highlight context-dependent effects of Notch activation during myogenesis, and demonstrate that Notch1 activity improves myotube's function as a stem cell niche.
Data availability
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Early-early stage Duchenne muscular dystrophy: quadricepsPublicly available at the NCBI Gene Expression Omnibus (Accession no: GDS3027).
Article and author information
Author details
Funding
National Institute of Arthritis and Musculoskeletal and Skin Diseases (AR060652)
- Shihuan Kuang
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All procedures involving mice were approved by Purdue University's Animal Care and Use Committee under protocol # 1112000440.
Copyright
© 2016, Bi et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Stage-specific effects of Notch activation during skeletal myogenesis
eLife 5:e17355.
https://doi.org/10.7554/eLife.17355
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