Skeletal muscle stem cells are essential to muscle homeostasis and regeneration after injury, and have emerged as a promising cell source for treating skeletal disorders. An attractive approach to obtain these cells utilizes differentiation of pluripotent stem cells (PSCs). We recently reported that teratomas derived from mouse PSCs are a rich source of skeletal muscle stem cells. Here, we showed that teratoma formation is also capable of producing skeletal myogenic progenitors from human PSCs. Using single-cell transcriptomics, we discovered several distinct skeletal myogenic subpopulations that represent progressive developmental stages of the skeletal myogenic lineage and recapitulate human embryonic skeletal myogenesis. We further discovered that ERBB3 and CD82 are effective surface markers for prospective isolation of the skeletal myogenic lineage in human PSC-derived teratomas. Therefore, teratoma formation provides an accessible model for obtaining human skeletal myogenic progenitors from PSCs.

Differentiation of pluripotent stem cells (PSCs) is a promising approach to obtaining large quantities of skeletal myogenic progenitors for disease modeling and cell-based therapy. However, generating skeletal myogenic cells with high regenerative potential is still challenging. We recently reported that skeletal myogenic progenitors generated from mouse PSC-derived teratomas possess robust regenerative potency. We have also found that teratomas derived from human PSCs contain a skeletal myogenic population. Here, we showed that these human PSC-derived skeletal myogenic progenitors had exceptional engraftability. A combination of cell surface markers, CD82, ERBB3, and NGFR enabled efficient purification of skeletal myogenic progenitors. These cells expressed PAX7 and were able to differentiate into MHC+ multinucleated myotubes. We further discovered that these cells are expandable in vitro. Upon transplantation, the expanded cells formed new dystrophin⁺ fibers that reconstituted almost ¾ of the total muscle volume, and repopulated the muscle stem cell pool. Our study, therefore, demonstrates the possibility of producing large quantities of engraftable skeletal myogenic cells from human PSCs.