Human ES- and iPS-Derived Myogenic Progenitors Restore DYSTROPHIN and Improve Contractility upon Transplantation in Dystrophic Mice

Abstract

SUMMARY A major obstacle in the application of cell-based therapies for the treatment of neuromuscular disorders is obtaining the appropriate number of stem/progenitor cells to produce effective engraftment. The use of embryonic stem (ES) or induced pluripotent stem (iPS) cells could overcome this hurdle. However to date, derivation of engraftable skeletal muscle precursors that can restore muscle function from human pluripotent cells has not been achieved. Here we applied conditional expression of Pax7 in human ES/iPS cells to successfully derive large quantities of myogenic precursors, which upon transplantation into dystrophic muscle, are able to engraft efficiently, producing abundant human-derived dystrophin-positive myofibers that exhibit superior strength. Importantly, transplanted cells also seed the muscle satellite cell compartment and engraftment is present over 11 months post-transplant. This study provides the proof-of-principle for the derivation of functional skeletal myogenic progenitors from human ES/iPS cells, and highlights their potential for future therapeutic application in muscular dystrophies.

Zscan4 promotes genomic stability during reprogramming and dramatically improves the quality of iPS cells as demonstrated by tetraploid complementation

“…Although significant progress has been made in terms of improving the efficiency of iPS cell generation through the use of chemical compounds [46,47] and different cell types [48,49], interfering with the epigenetic status of donor cells [50][51][52], or modulating different signal pathways [34,53,54], the quality of iPS cells to date is not significantly improved or even getting worse when the p53 was absent to facilitate reprogramming [35]. On the other hand, regarding the safety concerns of iPS cells, strategies of generating integration-free iPS cells have been developed [55]; however, these reprogramming processes are extremely inefficient and the quality of resulting integration-free iPS cells still needs to be completely characterized [56]. In our study, we identified Zscan4 as a factor, essential for cleavage development of mouse embryos [23], which not only remarkably promotes the efficiency of iPS cell generation, but also significantly improves the quality of iPS cells by stabilizing the genomic and telomere DNA and promoting the telomere elongation at early stage of reprogramming.…”

Augmentation of Musculoskeletal Regeneration: Role for Pluripotent Stem Cells

“…This bypasses the requirement for early inductive signals from the notochord and neural tube, and provides a method for generating larger quantities of myogenic progenitors, compared with non-genetic techniques. Cells derived from both ESCs and iPSCs have been transplanted into models of MD with some success, demonstrating an overall improvement in functional capacity in terms of muscle force generation [106,[109][110][111]. Myogenic induction of ESCs and iPSCs has also been shown by inducing expression of Met Activating Genetically Improved Chimeric Factor-1 [112].…”

“…Excisable, non-integrating vectors overcome these issues but are typically less efficient. However, use of animal sera remains an issue, as serum is frequently used as a stimulus for terminal myogenic differentiation [106,110,111], and is therefore a limiting factor in clinical application.…”

Cell Transplantation and “Stem Cell Therapy” in the Treatment of Myopathies: Many Promises in Mice, Few Realities in Humans

“…Induced pluripotent stem cells are pluripotent cells with properties similar to embryonic stem cells obtained by reprogramming somatic cells such as fibroblasts [219,220]. In this sense, there were already experiences that demonstrated the possibility of producing myoblasts from induced pluripotent stem cells obtained from mice [221][222][223][224] and humans [225].…”