Dual Adeno-Associated Virus 9 with Codon-Optimized DYSF Gene Promotes In Vivo Muscle Regeneration and May Decrease...

Area of Science:

• Molecular biology
• Gene therapy
• Muscle regeneration

Background:

• Dysferlinopathy is a muscular dystrophy with no effective treatments.
• Gene therapy using adeno-associated virus (AAV) vectors is a promising therapeutic strategy.
• A dual-vector system was developed to deliver a codon-optimized DYSF gene.

Purpose of the Study:

• To evaluate the efficacy of AAV-mediated gene therapy for dysferlinopathy.
• To investigate muscle regeneration and inflammatory response after AAV.DYSF.OVERLAP delivery.
• To assess the impact of subphysiological dysferlin expression on muscle tissue.

Main Methods:

• Generation of a dual-vector AAV system (AAV.DYSF.OVERLAP) with overlapping DYSF cDNA sequences.
• In vitro studies using artificial myoblasts derived from dysferlin-deficient fibroblasts.
• In vivo studies in a dysferlinopathy murine model (Bla/J) with histological, morphometric, and immunohistochemical analyses.

Main Results:

• Dysferlin mRNA and protein were detected in transduced cells in vitro and in vivo at subphysiological levels.
• AAV.DYSF.OVERLAP delivery led to a reduction in necrotic muscle fibers and inflammatory changes in vivo.
• Nearly 35% of myofibers were transduced in the highest dose group, showing improved muscle structure.

Conclusions:

• AAV-based dual-vector systems are effective for delivering the DYSF gene.
• Subphysiological dysferlin expression can restore muscle tissue structure and reduce inflammation.
• Further studies are needed to assess long-term effects and the impact on the inflammatory component.