Induced Pluripotent Stem Cells derived Muscle Progenitors Effectively Mitigate Muscular Dystrophy through Restoring the Dystrophin Distribution.

BACKGROUND: Duchenne Muscular Dystrophy (DMD) is a recessive form of muscular disorder, resulting from the dystrophin gene mutations in X-chromosome. Application of embryonic stem cells or adult stem cells has demonstrated the therapeutic effects on DMD through both cell-based and non-cell based mechanisms. In this study, we proposed that Myogenic Progenitor Cells from Induced Pluripotent Stem Cells (iPSC-MPCs) would be more effective in repairing muscle damage caused by muscular dystrophy.

METHODS AND RESULTS: Mouse iPSCs were cultured in myogenic differentiation culture medium and the MPCs were characterized using Reverse Transcription Polymerase Chain Reaction (RT-PCR) and flow cytometry. iPSCs were successfully converted into MPCs, as evidenced by the distinct expression of myogenic genes and cell surface markers. The muscle injury was induced in tibialis muscle of mdx mouse by cardiotoxin injection, and the iPSC-MPCs were then engrafted into the damage site. Firefly luciferase expression vector was transduced into iPSC-MPCs and the in vivo bioluminescence imaging analysis revealed that these progenitor cells survived even at 30-days post transplantation. Importantly, histological analysis revealed that the central nuclei percentage, as well as fibrosis, was significantly reduced in the iPSC-MPCs treated muscle. In addition,the transplantation of progenitor cells restored the distributions of dystrophin and nicotinic acetylcholine receptors together with up-regulation of pair box protein 7(Pax7), a myogenic transcription factor.

CONCLUSION: iPSCs-derived MPCs exert strong therapeutic effects on muscular dystrophy by restoring dystrophin expression and acetylcholine receptor distribution.