Assessment of physiological parameters in the application of a double adeno-associated virus 9 with a codon-optimized DYSF gene for limb girdle muscular dystrophy type R2

Introduction: Gene therapy for Myoshi myopathy is extremely relevant, as it may become the first pathogenetic treatment for dysferlinopathy. The aim of this study was to study the efficacy and safety of the use of a genetic construct, the AAV9-DYSF-DV3’ virus, for the treatment of limb girdle muscular dystrophy LGMD) type R2. Materials and Methods: Mouse models of limb girdle muscular dystrophy type R2 В6.А-Dysfprmd/GeneJ were used to study the effectiveness of AAV9.DYSF drug and the corresponding C57BL/6J controls were used. During the study, muscle activity was determined on the basis of the following tests: “Grip test”, “Holding an animal on a slippery surface of a vertical rod”, “Forced swimming with a load”, and ”Wire hanging”. In the course of acute and subchronic toxicity, hematological and biochemical blood tests of the rats, histological analysis and ”Open field” behavioral testing were performed. Results and Discussion: In this study, for the first time, a comprehensive investigation of the effectiveness of gene therapy using the two-vector system of adeno-associated AAV9-DYSF-DV3’ virus with overlapping DYSF cDNA sequences was conducted in a mouse model of limb girdle muscular dystrophy type 2 R. Conclusion: During the testing of the drug’s effectiveness, it was discovered that drug AAV9.DYSF showed the best effectiveness in mice with the absence of the protein dysferlin in behavioral testing at the maximum dose (5*1012) with a double intramuscular injection. In the “Grip test”, the index in В6.А-Dysfprmd/GeneJ mice increased by 29% (p=0.0026) relative to that in the K-group. In the tests “Forced swimming with a load”, ”Wire hanging”, and ”Holding an animal on a slippery surface of a vertical rod”, the indicators also improved by 80% (p=0.0019), 104.8% (p=0.001) and 20% (p=0.025), respectively, relative to those of the negative control. During acute and subchronic toxicity, the administration of the drug to animals does not cause death or intoxication.