Yin Zi, Lin Junxin, Yan Ruojin, Liu Richun, Liu Mengfei, Zhou Bo, Zhou Wenyan, An Chengrui, Chen Yangwu, Hu Yejun, Fan Chunmei, Zhao Kun, Wu Bingbing, Zou Xiaohui, Zhang Jin, El-Hashash Ahmed H, Chen Xiao, Ouyang Hongwei
Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, and Department of Orthopedic Surgery of Sir Run Run Shaw Hospital Zhejiang University School of Medicine Hangzhou 310058 China.
Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province Zhejiang University School of Medicine Hangzhou 310058 China.
Adv Sci (Weinh). 2020 Oct 22;7(23):2000938. doi: 10.1002/advs.202000938. eCollection 2020 Dec.
Although being of utmost importance for human health and mobility, stem cell identity and hierarchical organization of musculoskeletal progenitors remain largely unexplored. Here, cells from E10.5, E12.5, and E15.5 murine limbs are analyzed by high throughput single-cell RNA sequencing to illustrate the cellular architecture during limb development. Single-cell transcriptional profiling demonstrates the identity and differentiation architecture of musculoskeletal stem cells (MSSC), soft and hard tissue progenitors through expression pattern of musculoskeletal markers (scleraxis [], , , and ). This is confirmed by genetic in vivo lineage tracing. Moreover, single-cell analyses of Scx knockout mice tissues illustrates that regulates MSSC self-renewal and proliferation potential. A high-throughput and low-cost multi-tissues RNA sequencing strategy further provides evidence that musculoskeletal system tissues, including muscle, bone, meniscus, and cartilage, are all abnormally developed in Scx knockout mice. These results establish the presence of an indispensable limb Scx+Hoxd13+ MSSC population and their differentiation into soft tissue progenitors () and hard tissue progenitors (). Collectively, this study paves the way for systematically decoding the complex molecular mechanisms and cellular programs of musculoskeletal tissues morphogenesis in limb development and regeneration.
尽管对于人类健康和活动能力至关重要，但肌肉骨骼祖细胞的干细胞特性和层次组织在很大程度上仍未得到探索。在这里，通过高通量单细胞RNA测序分析来自E10.5、E12.5和E15.5小鼠肢体的细胞，以阐明肢体发育过程中的细胞结构。单细胞转录谱通过肌肉骨骼标记物（硬骨素[]、[]、[]和[]）的表达模式展示了肌肉骨骼干细胞（MSSC）、软组织祖细胞和硬组织祖细胞的特性及分化结构。这通过体内遗传谱系追踪得到证实。此外，对Scx基因敲除小鼠组织的单细胞分析表明，[]调节MSSC的自我更新和增殖潜能。一种高通量、低成本的多组织RNA测序策略进一步提供了证据，表明包括肌肉、骨骼、半月板和软骨在内的肌肉骨骼系统组织在Scx基因敲除小鼠中均发育异常。这些结果证实了不可或缺的肢体Scx+Hoxd13+MSSC群体的存在，以及它们向软组织祖细胞（[]）和硬组织祖细胞（[]）的分化。总的来说，这项研究为系统解码肢体发育和再生过程中肌肉骨骼组织形态发生的复杂分子机制和细胞程序铺平了道路。
