Organoid Culture Promotes Dedifferentiation of Mouse Myoblasts into Stem Cells Capable of Complete Muscle Regeneration

Experimental cell therapies for skeletal muscle conditions have shown little success, primarily because they used committed myogenic progenitors rather than true muscle stem cells, known as satellite cells. Here we present a method to generate in vitro–derived satellite cells (idSCs) from skeletal muscle tissue. When transplanted in small numbers into mouse muscle, mouse idSCs fuse into myofibers, repopulate the satellite cell niche, self-renew, support multiple rounds of muscle regeneration, and improve force production on par with freshly isolated satellite cells. in damaged skeletal muscle. We profiled the epigenomic and transcriptional differences between idSCs and satellite cells, and used these differences to identify core signaling pathways and genes that confer idSC functionality. Finally, fromhuman muscle biopsies we successfully generated satellite cell–like cells in vitro. After further development, idSCs may provide a scalable source of cells for the treatment of genetic muscle disorders, trauma-induced muscle damage and age-related muscle weakness. Overall design: ATAC-seq was performed on mouse satellite cells, myoblasts, and in vitro-derived satellite cells at 10, 20, and 30 days of generation.

针对骨骼肌疾病的实验性细胞疗法迄今收效甚微，究其核心原因在于此类疗法所使用的是已定向分化的肌源性祖细胞，而非被称为卫星细胞（satellite cells）的真正肌肉干细胞。本研究报道了一种可从骨骼肌组织中体外培养获得卫星细胞（in vitro–derived satellite cells，简称idSCs）的方法。将少量小鼠idSCs移植至受损骨骼肌内后，其可融合至肌纤维中，重新定植于卫星细胞微环境，实现自我更新，支持多轮肌肉再生，且其肌力恢复效果与新鲜分离的卫星细胞相当。本研究对idSCs与天然卫星细胞之间的表观基因组和转录组差异进行了全景分析，并借此筛选出赋予idSCs功能特性的核心信号通路与功能基因。最后，本研究从人类肌肉活检样本中成功体外培养获得类卫星细胞。经进一步优化后，idSCs有望成为可规模化获取的细胞来源，用于治疗遗传性肌肉疾病、创伤性肌肉损伤以及年龄相关性肌肉衰弱。实验整体设计：本研究对小鼠卫星细胞、成肌细胞以及体外培养第10、20、30天的idSCs进行了ATAC-seq测序分析。