Parise Gianni, O'Reilly Ciara E, Rudnicki Michael A
Department of Kinesiology, McMaster University, 1280 Main St. W., Hamilton, ON L8S 4K1, Canada.
Appl Physiol Nutr Metab. 2006 Dec;31(6):773-81. doi: 10.1139/h06-055.
Skeletal muscle regeneration and adaptation to exercise require the actions of muscle satellite cells. Muscle satellite cells are thought to play an integral role in the process of exercise adaptation, but have also been shown to possess the capacity to fully regenerate muscle tissue following destructive muscle injury. We now know that molecular regulation of satellite cells involves the coordinated actions of a series of transcriptional networks that leads to myogenic commitment, cell-cycle entry, proliferation, and terminal differentiation. Additionally, Pax7 is a paired-box transcription factor that has been identified as playing a critical role in satellite cell regulation. It remains debatable, however, whether Pax7 is required for the specification of satellite cells and (or) whether it is playing a vital role in self-renewal and maintenance of the satellite cell population. In recent years, the emergence of atypical myogenic progenitor populations has added a new dimension to muscle repair, and significant interest has been focused on identifying populations such as bone-marrow-derived stem cells that have the ability to contribute to muscle. Interestingly, elucidating the molecular regulation of myogenic progenitor populations has involved animal models of muscle regeneration, with questionable relevance for human muscle adaptation to exercise. This paper highlights the current state of knowledge on the molecular regulation of satellite cells, explores the potential contribution of atypical myogenic progenitors, and discusses the information gathered from animal regeneration models in terms of its relevance to the process of exercise adaptation.
骨骼肌再生及对运动的适应性需要肌肉卫星细胞发挥作用。肌肉卫星细胞被认为在运动适应过程中起着不可或缺的作用，但研究也表明，在肌肉受到损伤破坏后，它们具备使肌肉组织完全再生的能力。我们现在知道，卫星细胞的分子调控涉及一系列转录网络的协同作用，这些作用会导致肌源性定向分化、细胞周期进入、增殖以及终末分化。此外，配对盒转录因子Pax7已被确定在卫星细胞调控中起关键作用。然而，Pax7对于卫星细胞的特化是否必要以及（或者）它在卫星细胞群体的自我更新和维持中是否发挥至关重要的作用，仍存在争议。近年来，非典型肌源性祖细胞群体的出现为肌肉修复增添了新的维度，人们将大量兴趣集中在鉴定具有促进肌肉形成能力的群体，如骨髓来源的干细胞。有趣的是，阐明肌源性祖细胞群体的分子调控涉及肌肉再生的动物模型，但其与人类肌肉对运动的适应性的相关性存疑。本文重点介绍了卫星细胞分子调控的当前知识状态，探讨了非典型肌源性祖细胞的潜在贡献，并讨论了从动物再生模型收集的信息与运动适应过程的相关性。
