Somatic gene editing ameliorates skeletal and cardiac muscle failure in pig and human models of Duchenne muscular dystrophy

“Betwixt Mine Eye and Heart a League Is Took”: The Progress of Induced Pluripotent Stem-Cell-Based Models of Dystrophin-Associated Cardiomyopathy

“…The major problem is reduced lifespan (≤3 months) that precludes natural breeding and, therefore, dramatically impacts the uptake of this model [ 301 ]. However, the porcine MD model was recently used to test and validate somatic gene editing techniques that aimed to restore the DMD reading frame [ 302 ]. Intramuscular injection of AAV carrying Cas9 and a pair of guide RNAs targeting sequences flanking exon 51 into pigs with an exon 52 deletion restored the production of a shortened dystrophin protein and improved skeletal muscle function.…”

“…Intramuscular injection of AAV carrying Cas9 and a pair of guide RNAs targeting sequences flanking exon 51 into pigs with an exon 52 deletion restored the production of a shortened dystrophin protein and improved skeletal muscle function. Furthermore, systemic application of the same AAV vector caused widespread dystrophin expression, including in the diaphragm and heart, which prolonged survival and reduced arrhythmias [ 302 ]. Similar results were also obtained following genome editing of iPSCs derived from a DMD patient who had an exon 52 deletion.…”

“…Similar results were also obtained following genome editing of iPSCs derived from a DMD patient who had an exon 52 deletion. Skeletal and cardiac myocytes differentiated from this patient’s corrected iPSCs showed ameliorated skeletal myotube formation, cardiomyocyte Ca 2+ handling, and arrhythmia susceptibility [ 302 ]. This is a good example of a translational study in which a suitable animal model is combined with in vitro experiments using patient-derived cells.…”

“…In the last few years, iPSC-CMs have been widely used to model cardiac diseases including DAC, and more than 20 original articles reported the use of iPSC-derived cells from MD patients. Starting from the first iPSC line derived from skin fibroblasts of a DMD patient in 2008 [ 341 ], numerous other iPSC cell lines derived from different somatic-cell sources obtained from DMD and BMD patients were generated and published [ 133 , 253 , 302 , 342 , 343 , 344 , 345 , 346 , 347 , 348 , 349 , 350 , 351 , 352 , 353 , 354 , 355 , 356 , 357 , 358 , 359 , 360 , 361 , 362 , 363 , 364 , 365 , 366 , 367 , 368 ]. These works demonstrated that it is possible to use iPSC-derived cells carrying specific DMD mutations to reproduce MD pathogenesis and to verify new therapeutic approaches.…”

“…In addition to the study of DAC molecular mechanisms, the iPSC-CM platform has been widely used to test potential therapeutic strategies and, among these, genetic therapies were the most studied. Indeed, many works using iPSC-CMs demonstrated the amelioration of defects observed in DMD iPSC-CMs after restoring a truncated form of dystrophin achieved through exon skipping or delivery of micro- or minidystrophin [ 302 , 350 , 353 , 359 , 365 ]. Lin and colleagues demonstrated that treatment with the membrane sealant compound poloxamer 188 significantly decreased resting cytosolic Ca 2+ level, repressed caspase-3 activation, and consequently suppressed apoptosis in DMD iPSC-CMs [ 344 ].…”