iMyoblasts for ex vivo and in vivo investigations of human myogenesis and disease modeling

• Published in: eLife 2022-01, Vol.11
• Main Authors: Guo, Dongsheng, Daman, Katelyn, Chen, Jennifer Jc, Shi, Meng-Jiao, Yan, Jing, Matijasevic, Zdenka, Rickard, Amanda M, Bennett, Monica H, Kiselyov, Alex, Zhou, Haowen, Bang, Anne G, Wagner, Kathryn R, Maehr, René, King, Oliver D, Hayward, Lawrence J, Emerson, Jr, Charles P
• Format: Article
• Language: English
• Subjects: Animals; Biopsy; Cell Differentiation; Cell Line; Cell Lineage; Cells, Cultured; Developmental Biology; Disease; Disease Models, Animal; Epigenetics; Fetuses; Fibroblasts; Flow cytometry; Gene expression; Genome editing; Growth factors; Homeodomain Proteins - metabolism; human ipsc myogenesis; Humans; Immunofluorescence; iMyoblasts; Induced Pluripotent Stem Cells - cytology; Induced Pluripotent Stem Cells - transplantation; Mice; Muscle Development; muscle stem cells; Muscular dystrophy; Muscular Dystrophy, Facioscapulohumeral - pathology; Muscular Dystrophy, Facioscapulohumeral - therapy; Musculoskeletal system; Myoblasts; Myoblasts - transplantation; Myogenesis; Myotubes; Pax3 protein; PAX3 Transcription Factor - metabolism; Pluripotency; Population; Progenitor cells; Protocol; Recovery of Function; Regeneration; Skeletal muscle; Stem cell transplantation; Stem cells; Stem Cells and Regenerative Medicine; Tools and Resources; Transcriptomes; xenograft; Xenografts
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.70341

Skeletal muscle myoblasts (iMyoblasts) were generated from human induced pluripotent stem cells (iPSCs) using an efficient and reliable transgene-free induction and stem cell selection protocol. Immunofluorescence, flow cytometry, qPCR, digital RNA expression profiling, and scRNA-Seq studies identify iMyoblasts as a skeletal myogenic lineage with a fetal-like transcriptome signature, distinct from adult muscle biopsy myoblasts (bMyoblasts) and iPSC-induced muscle progenitors. iMyoblasts can be stably propagated for >12 passages or 30 population doublings while retaining their dual commitment for myotube differentiation and regeneration of reserve cells. iMyoblasts also efficiently xenoengrafted into irradiated and injured mouse muscle where they undergo differentiation and fetal-adult MYH isoform switching, demonstrating their regulatory plasticity for adult muscle maturation in response to signals in the host muscle. Xenograft muscle retains PAX3+ muscle progenitors and can regenerate human muscle in response to secondary injury. As models of disease, iMyoblasts from individuals with Facioscapulohumeral Muscular Dystrophy revealed a previously unknown epigenetic regulatory mechanism controlling developmental expression of the pathological gene. iMyoblasts from Limb-Girdle Muscular Dystrophy R7 and R9 and Walker Warburg Syndrome patients modeled their molecular disease pathologies and were responsive to small molecule and gene editing therapeutics. These findings establish the utility of iMyoblasts for ex vivo and in vivo investigations of human myogenesis and disease pathogenesis and for the development of muscle stem cell therapeutics.