Increased catalase expression improves muscle function in mdx mice.

Area of Science:

• Biomedical Science
• Genetics
• Muscle Physiology

Background:

• Oxidative stress is a known contributor to the pathology of Duchenne muscular dystrophy (DMD).
• The mdx mouse serves as a valuable model for studying DMD and testing potential therapeutic interventions.

Purpose of the Study:

• To investigate the therapeutic potential of catalase overexpression in improving muscle function in the mdx mouse model of DMD.
• To assess the impact of catalase on muscle strength, resistance to injury, and fatigue in dystrophic muscle.

Main Methods:

• Neonatal mdx mice were administered a recombinant adeno-associated virus carrying the catalase transgene.
• Muscle function, including specific tension, resistance to contraction-induced injury, and fatigue, was evaluated at 4, 6 weeks, and 6 months post-injection.
• Evaluated muscles included extensor digitorum longus, soleus, and diaphragm.

Main Results:

• Catalase overexpression generally improved muscle function across various time points.
• Significant improvements were observed in extensor digitorum longus specific tension and soleus fatigue resistance at 4 weeks.
• By 6 weeks and 6 months, catalase treatment reduced contraction-induced injury and fatigue in multiple muscle groups, including the diaphragm.

Conclusions:

• Catalase gene therapy demonstrates a capacity to enhance a subset of muscle function parameters in dystrophin-deficient skeletal muscle.
• These findings support the potential of antioxidant strategies, specifically catalase, for managing muscle pathology in Duchenne muscular dystrophy.