Human pluripotent stem cells (hPSCs) can be directed to differentiate into skeletal muscle progenitor cells (SMPCs). However, the myogenicity of hPSC-SMPCs relative to human fetal or adult satellite cells remains unclear. We observed that hPSC-SMPCs derived by directed differentiation are less functional in vitro and in vivo compared to human satellite cells. Using RNA sequencing, we found that the cell surface receptors ERBB3 and NGFR demarcate myogenic populations, including PAX7 progenitors in human fetal development and hPSC-SMPCs. We demonstrated that hPSC skeletal muscle is immature, but inhibition of transforming growth factor-β signalling during differentiation improved fusion efficiency, ultrastructural organization and the expression of adult myosins. This enrichment and maturation strategy restored dystrophin in hundreds of dystrophin-deficient myofibres after engraftment of CRISPR-Cas9-corrected Duchenne muscular dystrophy human induced pluripotent stem cell-SMPCs. The work provides an in-depth characterization of human myogenesis, and identifies candidates that improve the in vivo myogenic potential of hPSC-SMPCs to levels that are equal to directly isolated human fetal muscle cells.

中文翻译：

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ERBB3和NGFR标志着人类发育和hPSC中独特的骨骼肌祖细胞。

可以将人类多能干细胞（hPSC）定向分化为骨骼肌祖细胞（SMPC）。但是，相对于人类胎儿或成年卫星细胞，hPSC-SMPCs的肌原性尚不清楚。我们观察到，与人类卫星细胞相比，通过定向分化衍生的hPSC-SMPC在体外和体内的功能较弱。使用RNA测序，我们发现细胞表面受体ERBB3和NGFR划分了成肌种群，包括人类胎儿发育和hPSC-SMPCs中的PAX7祖细胞。我们证明了hPSC骨骼肌是不成熟的，但是在分化过程中抑制转化生长因子-β信号转导改善了融合效率，超微结构和成年肌球蛋白的表达。植入CRISPR-Cas9校正的杜兴氏肌营养不良症人类诱导的多能干细胞-SMPCs后，这种富集和成熟策略在数百个营养不良的肌纤维中恢复了营养不良。这项工作提供了人类肌发生的深入表征，并确定了将hPSC-SMPCs的体内肌发生潜能提高到与直接分离的人类胎儿肌肉细胞相等的水平的候选物。