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 (LGMD 2E) is caused by mutations in the β-sarcoglycan gene, which is expressed in skeletal, cardiac and smooth muscle. β-sarcoglycan deficient (Sgcb-null) mice develop severe muscular dystrophy and cardiomyopathy with focal areas of necrosis. Methods - We performed morphological (histological and cellular characterization) and functional (isometric tetanic force and fatigue) analyses in dystrophic mice. Comparisons studies were carried out in 1-month-old (clinical onset of the disease) and 7-month-old mice among controls (C57/BL6, Rag2/γc-null), immunocompetent and immunodeficient dystrophic mice (Sgcb-null, Sgcb/Rag2/γc-null mice respectively). Results - We provide evidence that the lack of an immunological system results in an increase in the calcification area in striated muscle without impairing extensor digitorum longus muscle performances. Sgcb/Rag2/γc-null muscles showed a significant reduction of AP+ mesoangioblasts. Discussion - The immunological system counteracts skeletal muscle degeneration in a murine model of LGMD 2E. This article is protected by copyright. All rights reserved.