Multi-parametric MRI at 14T for muscular dystrophy mice treated with AAV vector-mediated gene therapy

Area of Science:

• Biomedical Engineering
• Molecular Biology
• Medical Imaging

Background:

• Muscular dystrophy diagnosis and treatment monitoring often rely on invasive surgical biopsies, limiting data acquisition.
• Non-invasive tools are needed for comprehensive disease assessment and tracking treatment responses in muscular dystrophy.

Purpose of the Study:

• To evaluate quantitative magnetic resonance imaging (MRI) as a non-invasive method for monitoring gene therapy in muscular dystrophy.
• To assess the efficacy of micro-dystrophin gene therapy in dystrophic mdx4cv mice using multi-parametric MRI.

Main Methods:

• Dystrophic mdx4cv mice received systemic adeno-associated viral (AAV) vector gene therapy with micro-dystrophin.
• Multi-parametric MRI (T2, magnetization transfer, diffusion) and 3-D volume measurements were used to track disease/treatment progression over 24 weeks.
• Physiological assays, histological analysis, and MRI data were correlated to assess treatment efficacy.

Main Results:

• Micro-dystrophin gene therapy improved muscle histology, reducing necrosis and contraction-induced injury.
• T2 relaxation values decreased significantly in treated mice across multiple muscle groups, particularly the tibialis anterior.
• MRI findings, including hyper-intense regions correlating with pathology, provided valuable data for non-invasive monitoring.

Conclusions:

• Quantitative MRI is a viable non-invasive tool for monitoring gene therapy efficacy in muscular dystrophy.
• T2 relaxation, diffusion, and magnetization transfer MRI parameters offer insights into muscle health and treatment response.
• This non-invasive imaging approach can enhance disease assessment and guide therapeutic strategies for muscular dystrophy.