Full-Length Dysferlin Expression Driven by Engineered Human Dystrophic Blood-Derived CD133+ Stem Cells

The protein dysferlin is abundantly expressed in skeletal and cardiac muscles, where its main function is membrane repair. Mutations in the dysferlin gene are involved in two autosomal recessive muscular dystrophies: Miyoshi myopathy and limb-girdle muscular dystrophy type 2B. Development of effective therapies remains a great challenge. Strategies to repair the dysferlin gene by skipping mutated exons may be suitable only for a subset of mutations, while cell and gene therapy can be extended to all mutations. Herein, we show for the first time the in vitro production of full-length dysferlin mediated by a lentiviral vector in blood-derived CD133+ stem cells isolated from patients with Miyoshi myopathy. Transplantation of engineered blood-derived CD133+ stem cells into scid/blAJ mice resulted in sufficient dysferlin expression to correct functional deficits in skeletal muscle membrane repair. Multi-exon skipping of blood-derived CD133+ stem cells isolated from the same patients led to partial dysferlin reconstitution in vitro, but failed to ameliorate the dystrophic phenotype in vivo. Our data suggest that lentivirus-mediated delivery of full-length dysferlin in stem cells isolated from Miyoshi myopathy patients is a feasible strategy to develop novel therapeutic approaches for treatment of dysferlinopathies.