Cell-mediated exon skipping normalizes dystrophin expression and muscle function in a new mouse model of Duchenne Muscular Dystrophy

Abstract Cell therapy for muscular dystrophy has met with limited success, mainly due to the poor engraftment of donor cells, especially in fibrotic muscle at an advanced stage of the disease. We developed a cell-mediated exon skipping that exploits the multinucleated nature of myofibers to achieve cross-correction of resident, dystrophic nuclei by the U7 small nuclear RNA engineered to skip exon 51 of the dystrophin gene. We observed that co-culture of genetically corrected human DMD myogenic cells (but not of WT cells) with their dystrophic counterparts at a ratio of either 1:10 or 1:30 leads to dystrophin production at a level several folds higher than what predicted by simple dilution. This is due to diffusion of U7 snRNA to neighbouring dystrophic resident nuclei. When transplanted into NSG-mdx-Δ51mice carrying a mutation of exon 51, genetically corrected human myogenic cells produce dystrophin at much higher level than WT cells, well in the therapeutic range, and lead to force recovery even with an engraftment of only 3–5%. This level of dystrophin production is an important step towards clinical efficacy for cell therapy..

Synopsis In a new DMD mouse model, carrying a mutation of exon 51, transplantation of MABs expressing a U7 snRNA able to skip exon 51 and to diffuse into neighbouring dystrophic resident nuclei efficiently restored protein expression of dystrophin to a therapeutic level and led to a force recovery. We demonstrated that the U7 snRNA diffuses from the corrected nucleus along the cytoplasm of the muscle fibre, in vitro but also in vivo.The cross-correction of dystrophic neighbouring resident nuclei amplifies several folds dystrophin expression and reaches the presumed therapeutic level.We showed that a single injection is sufficient to maintain dystrophin expression for at least 11 months, a significant period of the mouse lifespan.We demonstrated that the increased production of dystrophin protein, due to the snRNA, results in the improvement of the motility of transplanted mice approaching the motility of WT mice..

In a new DMD mouse model, carrying a mutation of exon 51, transplantation of MABs expressing a U7 snRNA able to skip exon 51 and to diffuse into neighbouring dystrophic resident nuclei efficiently restored protein expression of dystrophin to a therapeutic level and led to a force recovery..

Medienart:	E-Artikel

Erscheinungsjahr:	2024
Erschienen:	2024

Enthalten in:	Zur Gesamtaufnahme - volume:16
Enthalten in:	EMBO Molecular Medicine - 16(2024), 4 vom: 04. März, Seite 927-944

Sprache:	Englisch

Beteiligte Personen:

Galli, Francesco [VerfasserIn] Bragg, Laricia [VerfasserIn] Rossi, Maira [VerfasserIn] Proietti, Daisy [VerfasserIn] Perani, Laura [VerfasserIn] Bagicaluppi, Marco [VerfasserIn] Tonlorenzi, Rossana [VerfasserIn] Sibanda, Tendai [VerfasserIn] Caffarini, Miriam [VerfasserIn] Talapatra, Avraneel [VerfasserIn] Santoleri, Sabrina [VerfasserIn] Meregalli, Mirella [VerfasserIn] Bano-Otalora, Beatriz [VerfasserIn] Bigot, Anne [VerfasserIn] Bozzoni, Irene [VerfasserIn] Bonini, Chiara [VerfasserIn] Mouly, Vincent [VerfasserIn] Torrente, Yvan [VerfasserIn] Cossu, Giulio [VerfasserIn]

Links:	Volltext [kostenfrei]

Themen:	Cell Therapy Duchenne Muscular Dystrophy Exon Skipping Mesoangioblast Regenerative Medicine

Anmerkungen:	© The Author(s) 2024

doi:	10.1038/s44321-024-00031-3

funding:
Förderinstitution / Projekttitel:

PPN (Katalog-ID):	SPR055534805