Duchenne Muscular Dystrophy Myogenic Cells from Urine-Derived Stem Cells Recapitulate the Dystrophin Genotype and Phenotype

A ready source of autologous myogenic cells is of vital importance for drug screening and functional genetic studies in Duchenne muscular dystrophy (DMD), a rare disease caused by a variety of dystrophin gene mutations. As stem cells (SCs) can be easily and noninvasively obtained from urine specimens, we set out to determine whether they could be myogenically induced and useful in DMD research. To this end, we isolated stem cells from the urine of two healthy donors and from one patient with DMD, and performed surface marker characterization, myogenic differentiation (MyoD), and then transfection with antisense oligoribonucleotides to test for exon skipping and protein restoration. We demonstrated that native urine-derived stem cells express the full-length dystrophin transcript, and that the dystrophin mutation was retained in the cells of the patient with DMD, although the dystrophin protein was detected solely in control cells after myogenic transformation according to the phenotype. Notably, we also showed that treatment with antisense oligoribonucleotide against dystrophin exon 44 induced skipping in both native and MyoD-transformed urine-derived stem cells in DMD, with a therapeutic transcript-reframing effect, as well as visible protein restoration in the latter. Hence MyoD-transformed cells may be a good myogenic model for studying dystrophin gene expression, and native urine stem cells could be used to study the dystrophin transcript, and both diagnostic procedures and splicing modulation therapies in both patients and control subjects, without invasive and costly collection methods. New, bankable bioproducts from urine stem cells, useful for prescreening studies and therapeutic applications alike, are also foreseeable after further, more in-depth characterization.