Morphological and functional analyses of skeletal muscles from an immunodeficient animal model of limb‐girdle muscular dystrophy type 2E

Introduction: Limb‐girdle muscular dystrophy type 2E (LGMD2E) is caused by mutations in the β‐sarcoglycan gene, which is expressed in skeletal, cardiac, and smooth muscles. β‐Sarcoglycan‐deficient (Sgcb‐null) mice develop severe muscular dystrophy and cardiomyopathy with focal areas of necrosis. Methods: In this study we performed morphological (histological and cellular characterization) and functional (isometric tetanic force and fatigue) analyses in dystrophic mice. Comparison studies were carried out in 1‐month‐old (clinical onset of the disease) and 7‐month‐old control mice (C57Bl/6J, Rag2/γc‐null) and immunocompetent and immunodeficient dystrophic mice (Sgcb‐null and Sgcb/Rag2/γc‐null, respectively). Results: We found that the lack of an immunological system resulted in an increase of calcification in striated muscles without impairing extensor digitorum longus muscle performance. Sgcb/Rag2/γc‐null muscles showed a significant reduction of alkaline phosphate‐positive mesoangioblasts. Discussion: The immunological system counteracts skeletal muscle degeneration in the murine model of LGMD2E. Muscle Nerve 58: 133–144, 2018