Human Induced Pluripotent Stem Cells: Challenges and Opportunities in Developing New Therapies for Muscular Dystrophies

Abstract

The generation of human induced pluripotent stem cells (iPSCs) has offered unparalleled opportunities for modelling human diseases and drug discovery. Muscular dystrophies are devastating inherited skeletal muscle disorders, for which there is no effective treatment. Recent breakthroughs in myogenic differentiation of iPSCs and other key technologies, including genome editing, smart biomaterials and tissue engineering, have opened new avenues to overcome the hurdles of developing therapies for previously incurable muscle diseases. The synergy between these novel technologies is increasingly transforming the fields of disease modelling, drug screening and regenerative medicine. Key Concepts Traditionally, muscular dystrophy research relies on primary human cells that have a limited expansion potential, and on animal models that do not fully recapitulate human pathophysiology. The self‐renewal and differentiation properties of human induced pluripotent stem cells (iPSCs) make them an important resource for generating a large quantity of physiology‐relevant cell types to model human diseases in vitro . In combination with genome editing and transgene‐free myogenic differentiation, human iPSCs can provide an unlimited supply of genetically corrected myogenic progenitor cells for autologous cell therapy and lay the basis for large‐scale drug screening. Safety concerns regarding iPSCs and myogenic differentiation can be addressed by integration‐free reprogramming methods and transgene‐free differentiation protocols. Recent breakthroughs in smart biomaterials and tissue engineering facilitate the transition from 2D monotypic to 3D multilineage cell cultures that resemble human tissue architecture. The synergy between human iPSCs, genome editing, transgene‐free myogenic differentiation, advanced biomaterials and tissue engineering can exploit the full potential of human iPSCs and facilitate drug discovery and cell therapies, leading towards translation of biomedical research from bench to bedside.

Optogenetic modeling of human neuromuscular circuits in Duchenne muscular dystrophy with CRISPR and pharmacological corrections

“…This highlights the importance of generating appropriate isogenic controls using recently developed genome editing tools (Fig. 1A) (15).…”

“…The advent of human pluripotent stem cells (PSCs) and transgenefree myogenic differentiation has opened new avenues of research into muscular dystrophies and drug discovery (15,16). For instance, patient-specific PSC-derived skeletal muscle has been shown to recapitulate some pathological features of DMD in monotypic twodimensional (2D) cultures, including reduced myoblast fusion competence, abnormal expression of inflammation-related genes, and up-regulation of transforming growth factor- (TGF)/bone morphogenetic protein signaling (17).…”

“…In contrast to conventional monotypic 2D cultures, recent advances in 3D multilineage cultures can better mimic the complex human tissue architecture and physiology in vivo (15). In particular, compartmentalized microdevices and organ-on-a-chip technologies have recently been exploited to recapitulate physiological conditions and model nerve-muscle connectivity in the context of MN disease, amyotrophic lateral sclerosis (ALS) (18,19).…”

A new patient‐derived iPSC model for dystroglycanopathies validates a compound that increases glycosylation of α‐dystroglycan

“…Targeted gene correction of FKRP-iPSCs using CRISPR/Cas9mediated genome editing A common issue of patient-specific iPSCs in disease modeling is the lack of appropriate isogenic control cells, causing concerns about the effect of genetic backgrounds on phenotypic variability [50]. To overcome this issue, we applied a precise genome-editing strategy to correct the FKRP c.1364C>A (p.A455D) mutation using site-specific endonuclease CRISPR/Cas9 stimulated homologous recombination [44,45], which consists of a single-guide RNA (sgRNA), the Cas9 nuclease, and a donor-targeting vector.…”

CRISPR-mediated correction of skeletal muscle Ca2+handling in a novel DMD patient-derived pluripotent stem cell model

“…Recent studies have highlighted the opportunities and challenges of human pluripotent stem cell (PSC)-derived skeletal muscle as a disease model to develop novel therapies for muscular dystrophies [18, 19]. Here we have generated a novel DMD patient-derived PSC line carrying the DMD c.8868delC mutation and used CRISPR-mediated genome editing to precisely correct the DMD mutation generating a corresponding isogenic control line.…”