Sorbonne Université, INSERM UMRS-974 and Institut de Myologie, 75013 Paris, France.
Department of Biology, Faculty of Arts and Sciences, Holy Spirit University of Kasik (USEK), Jounieh 446, Lebanon.
Cells. 2021 Feb 4;10(2):318. doi: 10.3390/cells10020318.
Skeletal muscle is composed of multinucleated, mature muscle cells (myofibers) responsible for contraction, and a resident pool of mononucleated muscle cell precursors (MCPs), that are maintained in a quiescent state in homeostatic conditions. Skeletal muscle is remarkable in its ability to adapt to mechanical constraints, a property referred as muscle plasticity and mediated by both MCPs and myofibers. An emerging body of literature supports the notion that muscle plasticity is critically dependent upon nuclear mechanotransduction, which is transduction of exterior physical forces into the nucleus to generate a biological response. Mechanical loading induces nuclear deformation, changes in the nuclear lamina organization, chromatin condensation state, and cell signaling, which ultimately impacts myogenic cell fate decisions. This review summarizes contemporary insights into the mechanisms underlying nuclear force transmission in MCPs and myofibers. We discuss how the cytoskeleton and nuclear reorganizations during myogenic differentiation may affect force transmission and nuclear mechanotransduction. We also discuss how to apply these findings in the context of muscular disorders. Finally, we highlight current gaps in knowledge and opportunities for further research in the field.
骨骼肌由多能核、成熟的肌肉细胞(肌纤维)组成,负责收缩,还有一个常驻的单核肌肉细胞前体(MCPs)池,在稳态条件下处于静止状态。骨骼肌具有适应机械约束的能力,这种特性被称为肌肉可塑性,并由 MCPs 和肌纤维共同介导。越来越多的文献支持这样一种观点,即肌肉可塑性取决于核机械转导,即将外部物理力转化为核内产生生物学反应的过程。机械加载会引起核变形、核纤层组织改变、染色质凝聚状态和细胞信号转导的变化,最终影响成肌细胞命运的决定。本综述总结了目前关于 MCPs 和肌纤维中核力传递机制的研究进展。我们讨论了肌生成分化过程中细胞骨架和核重排如何影响力的传递和核机械转导。我们还讨论了如何将这些发现应用于肌肉疾病的背景。最后,我们强调了该领域目前知识上的差距和进一步研究的机会。