Rat models of musculoskeletal lysosomal storage disorders and their role in pre-clinical evaluation of gene therapy approaches

Mice have been a cornerstone of biomedical research for decades for studying a wide range of biological processes, disease mechanisms, and the assessment of therapies. Moreover, mice present several practical advantages such as small size, low cost and ease of genetic manipulation. While mice offer numerous benefits, for certain disease areas, rat models provide a closer representation of human disease progression, offering better insights for translational research and therapeutic development. This closer resemblance is particularly important for research focusing on diseases involving the cardiovascular and musculoskeletal system. In rats, the pathophysiology of these diseases mirrors the clinical alterations observed in humans. This review focuses on the key phenotypic differences between mouse and rat models of lysosomal storage disorders that specifically manifest with cardiac, skeletal muscle, and bone and joint involvement (Pompe and Danon diseases, and Maroteaux-Lamy and Morquio A syndromes). Furthermore, we discuss the therapeutic potential of various adeno-associated viral vector-mediated gene therapies that have been evaluated in these rat models, highlighting their contributions to advancing treatment options for these debilitating conditions.