Mature Myotubes Generated From Human-Induced Pluripotent Stem Cells Without Forced Gene Expression

Abstract

Human-induced pluripotent stem cells (hiPSCs) are a promising tool for disease modeling and drug screening. To apply them to skeletal muscle disorders, it is necessary to establish mature myotubes because the onset of many skeletal muscle disorders is after birth. However, to make mature myotubes, the forced expression of specific genes should be avoided, as otherwise dysregulation of the intracellular networks may occur. Here, we achieved this goal by purifying hiPSC-derived muscle stem cells (iMuSC) by Pax7-fluorescence monitoring and antibody sorting. The resulting myotubes displayed spontaneous self-contraction, aligned sarcomeres, and a triad structure. Notably, the phenotype of sodium channels was changed to the mature type in the course of the differentiation, and a characteristic current pattern was observed. Moreover, the protocol resulted in highly efficient differentiation and high homogeneity and is applicable to drug screening.

Establishment of quantitative and consistent in vitro skeletal muscle pathological models of myotonic dystrophy type 1 using patient-derived iPSCs

“…In particular, CDH13 is expressed in the majority of the myogenic cells and we efficiently acquired iMuSCs from the transgene-free culture. Furthermore, iMuSCs have the potential to generate more mature myotubes than MyoD1-mediated myotubes 22 . Hence, the transgene-free differentiation was conducted using a stepwise protocol to obtain iMuSCs and induce the iMuSCs to differentiate into highly mature myotubes (Fig.…”

“…The other is the iPSC-derived muscle stem cell (iMuSC) induction system, in which hiPSCs are induced to differentiate into fetal muscle stem cells (MuSCs) by recapitulating myogenesis 20 . The iMuSC shows a high regeneration potential in vivo and high myogenic capacity in vitro [20][21][22] .…”

Heparan Sulfate Chain‐Conjugated Laminin‐E8 Fragments Advance Paraxial Mesodermal Differentiation Followed by High Myogenic Induction from hiPSCs

“…Recently, we induced hiPSCs to generate myotubes with mature myotube characteristics, such as sarcomere, triad structures, and calcium homeostasis, which is a great model for muscular diseases and drug screening. [ 56 ] However, the variations among hiPSCs, such as the types of original cells or the genetic backgrounds of the donor cells, induce diversity in their differentiation propensity toward muscle lineages. [ 3 , 4 , 5 , 6 , 57 , 58 , 59 , 60 ] In the current study, we examined the myogenic differentiation of multiple muscular dystrophy patients derived hiPSC clones.…”