Bernard, et al
We have developed an optimised inducible system (opti-ox™) that enables tightly controlled expression of transcription factors improving cellular reprogramming approaches for the differentiation of hiPSCs. Through targeting of genomic safe harbour loci, we used opti-ox™ to achieve homogenous, inducible expression of the myogenic regulator MYOD1. MYOD1 induction leads to shutdown of the core pluripotency network, and activation of key myogenic factors including myosin heavy chain.
opti-ox™ reprogrammed ioSkeletal Myocytes express Desmin, Dystrophin and Titin, and form contractile, striated and multinucleated myocytes by Day 10 post-revival. Critically for metabolic studies, robust expression of the insulin-regulated glucose transporter GLUT4 is also detected. Importantly, skeletal myocytes produce a highly pure MHC positive population of cells within 4 days of thawing, comparable to day 10 transdifferentiated fibroblasts, and are suitable for phenotypic based HTS.