Selection of Optimal AAV Serotype for Brain-Wide Gene Delivery Following Intracerebroventricular Injection in mdx52 Mice

Abstract Adeno-associated virus (AAV)-based gene therapy is a promising approach for the treatment of Duchenne muscular dystrophy. In addition to muscle degeneration, patients exhibit cognitive and behavioral impairments, highlighting the need for efficient brain targeting. While several AAV serotypes efficiently transduce muscle and brain tissues, their diffusion remains limited. To address this challenge, this study aimed to compare the brain diffusion of different AAV serotypes in the mdx52 mouse model: AAV9, a peptide-modified AAV9 (PM-AAV9), AAVDJ, and AAVrh10. We evaluated AAV distribution using a GFP reporter gene following intracerebroventricular injection in neonatal or adult mice. Brain-wide transduction was assessed by fluorescence imaging and quantitative analysis. In addition, cell-type tropism was characterized through colocalization with neuronal and glial markers in the hippocampus, cortex, and cerebellum. Our results demonstrate that neonatal intracerebroventricular injection enhances brain-wide AAV distribution compared to adult delivery. Moreover, following neonatal intracerebroventricular injection, AAVrh10 shows superior brain diffusion and expression, with a predominant neuronal tropism across serotypes. These findings highlight the importance of serotype selection for optimizing central nervous system gene delivery. Overall, this study provides valuable insights for the development of AAV-based strategies targeting brain comorbidities in Duchenne muscular dystrophy, with potential applications to other neurological disorders.