Gattazzo Francesca, Laurent Béatrice, Relaix Frédéric, Rouard Hélène, Didier Nathalie
Univ Paris Est Creteil, INSERM, EFS, IMRB, Creteil 94010, France.
Univ Paris Est Creteil, INSERM, EFS, IMRB, Creteil 94010, France; EnvA, IMRB, Maisons-Alfort 94700, France; AP-HP, Hopital Mondor, Service d'Histologie, Creteil 94010, France.
Stem Cell Reports. 2020 Sep 8;15(3):597-611. doi: 10.1016/j.stemcr.2020.07.011. Epub 2020 Aug 6.
Muscle stem cells (or muscle satellite cells [MuSCs]) are required for postnatal growth. Yet, the detailed characterization of myogenic progression and establishment of quiescence during this process remains poorly documented. Here, we provide an overview of myogenic cells heterogeneity and dynamic from birth to adulthood using flow cytometry. We demonstrated that PAX7+ cells acquire an increasing ability to progress in the myogenic program from birth to adulthood. We then simultaneously analyzed the cycling state (KI67 expression) of the MuSCs and progenitors (PAX7+) and their progression into myogenic precursors (PAX7-MYOD+) and differentiating cells (MYOG+) in vivo. We identified two distinct peaks of myogenic differentiation between P7-P10 and P21-P28, and showed that the quiescent MuSC pool is established between 7 and 8 weeks of age. Overall our study provides a comprehensive in vivo characterization of myogenic heterogeneity and demonstrates the highly dynamic nature of skeletal muscle postnatal growth process.
肌肉干细胞（或肌肉卫星细胞[MuSCs]）是出生后生长所必需的。然而，在此过程中肌源性进展的详细特征以及静止状态的建立仍缺乏充分的文献记载。在这里，我们使用流式细胞术概述了从出生到成年的肌源性细胞异质性和动态变化。我们证明，从出生到成年，PAX7 +细胞在肌源性程序中进展的能力不断增强。然后，我们同时分析了MuSCs和祖细胞（PAX7 +）的细胞周期状态（KI67表达），以及它们在体内向肌源性前体细胞（PAX7-MYOD +）和分化细胞（MYOG +）的进展。我们在P7-P10和P21-P28之间确定了两个不同的肌源性分化峰，并表明静止的MuSC池在7至8周龄时建立。总体而言，我们的研究提供了肌源性异质性的全面体内特征，并证明了骨骼肌出生后生长过程的高度动态性质。
