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Three-dimensional niche stiffness synergizes with Wnt7a to modulate the extent of satellite cell symmetric self-renewal divisions
Satellite cells (SCs), the resident adult stem cells of skeletal muscle, are required for tissue repair throughout life. While many signaling pathways are known to control SC self-renewal, less is known about the mechanisms underlying the spatiotemporal control of self-renewal during skeletal muscle...
Autores principales: | , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The American Society for Cell Biology
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7521850/ https://www.ncbi.nlm.nih.gov/pubmed/32491970 http://dx.doi.org/10.1091/mbc.E20-01-0078 |
Sumario: | Satellite cells (SCs), the resident adult stem cells of skeletal muscle, are required for tissue repair throughout life. While many signaling pathways are known to control SC self-renewal, less is known about the mechanisms underlying the spatiotemporal control of self-renewal during skeletal muscle repair. Here, we measured biomechanical changes that accompany skeletal muscle regeneration and determined the implications on SC fate. Using atomic force microscopy, we quantified a 2.9-fold stiffening of the SC niche at time-points associated with planar-oriented symmetric self-renewal divisions. Immunohistochemical analysis confirms increased extracellular matrix deposition within the basal lamina. To test whether three-dimensional (3D) niche stiffness can alter SC behavior or fate, we embedded isolated SC-associated muscle fibers within biochemically inert agarose gels tuned to mimic native tissue stiffness. Time-lapse microscopy revealed that a stiff 3D niche significantly increased the proportion of planar-oriented divisions, without effecting SC viability, fibronectin deposition, or fate change. We then found that 3D niche stiffness synergizes with WNT7a, a biomolecule shown to control SC symmetric self-renewal divisions via the noncanonical WNT/planar cell polarity pathway, to modify stem cell pool expansion. Our results provide new insights into the role of 3D niche biomechanics in regulating SC fate choice. |
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