A scalable, clinically severe pig model for Duchenne muscular dystrophy

Abstract

Large animal models for Duchenne muscular dystrophy (DMD) are crucial for preclinical evaluation of novel diagnostic procedures and treatment strategies. Pigs cloned from male cells lacking DMD exon 52 (DMDΔ52) resemble molecular, clinical and pathological hallmarks of DMD, but cannot be propagated by breeding due to death before sexual maturity. Therefore, female DMD+/- carriers were generated. A single founder animal had 11 litters with 29 DMDY/-, 34 DMD+/- as well as 36 male and 29 female wild-type (WT) offspring. Breeding with F1 and F2 DMD+/- carriers resulted in additional 114 DMDY/- piglets. The majority of them survived for 3-4 months, providing large cohorts for experimental studies. Pathological investigations and proteome studies of skeletal muscles and myocardium confirmed the resemblance of human disease mechanisms. Importantly, DMDY/- pigs reveal progressive fibrosis of myocardium and increased expression of connexin-43, associated with significantly reduced left ventricular fractional shortening and ejection fraction already at age 3 months. Furthermore, behavioral tests provided evidence for impaired cognitive ability of DMDY/- pigs. Our breeding cohort of DMDΔ52 pigs and standardized tissue repositories from DMDY/- pigs, DMD+/- carriers, and WT littermate controls provide important resources for studying DMD disease mechanisms and for testing novel diagnostic procedures and treatment strategies.

CRISPR applications for Duchenne muscular dystrophy: From animal models to potential therapies

“…The male piglets lacked dystrophin expression and closely resembled the pathology of human disease including premature lethality, which prevented transmission of the mutation (Matsunari et al, 2018). Subsequent efforts using the same method in female cells successfully generated female carriers, which enabled establishment of a breeding cohort of DMD exon 52Δ pigs (Stirm et al, 2021). A DMD exon 52Δ Yucatan miniature pig model has also been generated by adeno‐associated virus‐mediated gene targeting and SCNT, generating seven piglets (Echigoya et al, 2021).…”

Proteomic profiling of impaired excitation–contraction coupling and abnormal calcium handling in muscular dystrophy

“…Based on the knowledge generated by proteomic cataloguing studies, a considerable number of comparative and mass spectrometry‐based investigations have determined proteome‐wide changes in various types of dystrophic skeletal muscle specimens using both restricted amounts of Duchenne/Becker's patient biopsy material [22, 137–139] and especially a large variety of spontaneous or bio‐engineered animal models including dystrophic mice, pigs and dogs [21, 23, 99, 127, 140–162]. General listings of proteomic biomarkers of dystrophinopathy, covering both muscle tissue and biofluids such as serum, have been published in extensive reviews [11–15, 24, 56].…”

“…Systematic mass spectrometric surveys of both patient muscle specimens and animal models of X‐linked muscular dystrophy have identified significant proteome‐wide disturbances/adaptations in cytoskeletal networks, the extracellular matrix, the contractile apparatus, energy metabolism and the cellular stress response in contractile fibres [21–23]. These complex alterations in specific muscle‐associated proteoforms agree with the highly progressive pathogenesis of dystrophinopathy [24].…”