Abstract:
Injury to skeletal muscle through trauma, physical activity, or disease initiates a process called muscle regeneration. When injured myofibers undergo necrosis, muscle regeneration gives rise to myofibers that have myonuclei in a central position, which contrasts the normal, peripheral position of myonuclei. Myofibers with central myonuclei are called regenerating myofibers and are the hallmark feature of muscle regeneration. An important and underappreciated aspect of muscle regeneration is the maturation of regenerating myofibers into a normal sized myofiber with peripheral myonuclei. Strikingly, very little is known about processes that govern regenerating myofiber maturation after muscle injury. As knowledge of myofiber formation and maturation during embryonic, fetal, and postnatal development has served as a foundation for understanding muscle regeneration, this narrative review discusses similarities and differences in myofiber maturation during muscle development and regeneration. Specifically, we compare and contrast myonuclear positioning, myonuclear accretion, myofiber hypertrophy, and myofiber morphology during muscle development and regeneration. We also discuss regenerating myofibers in the context of different types of myofiber necrosis (complete and segmental) after muscle trauma and injurious contractions. The overall goal of the review is to provide a framework for identifying cellular and molecular processes of myofiber maturation that are unique to muscle regeneration.
摘要:
创伤对骨骼肌的伤害,身体活动,或者疾病启动了一个叫做肌肉再生的过程。当受伤的肌纤维发生坏死时,肌肉再生产生肌纤维,有肌核在中央位置,这与正常情况相反,肌核的外周位置。具有中央肌核的肌纤维被称为再生肌纤维,并且是肌肉再生的标志特征。肌肉再生的一个重要且未被重视的方面是使肌纤维再生为具有外周肌核的正常大小的肌纤维的成熟。引人注目的是,对肌肉损伤后控制肌纤维再生成熟的过程知之甚少。由于了解了胚胎过程中肌纤维的形成和成熟,胎儿,出生后的发育是了解肌肉再生的基础,这篇叙述性综述讨论了肌肉发育和再生过程中肌纤维成熟的异同。具体来说,我们比较和对比肌核定位,肌核增生,肌纤维肥大,肌肉发育和再生过程中的肌纤维形态。我们还讨论了肌肉创伤和伤害性收缩后不同类型的肌纤维坏死(完全和节段性)的情况下的肌纤维再生。该综述的总体目标是提供一个框架,用于识别肌肉再生所特有的肌纤维成熟的细胞和分子过程。