Differential histological features and myogenic protein levels in distinct muscles of d‐sarcoglycan null muscular dystrophy mouse model.



Poster Number: T356


Anya Ayelen Valdez Hernandez, MD/PhD, PECEM-MD/PhD, Faculty of Medicine, National Autonomous University of Mexico, Silvia Garcia, MD, National Medical Center, 20 de Noviembre, Institute of Security and Social Services of State Workers, Patricia Canto, MD/PhD, Obesity Research Unit, Faculty of Medicine, National Autonomous University of Mexico, Alejandro Zentella Dehesa, PhD, Biomedical Research Institute, National Autonomous University of Mexico, Ramón Mauricio Coral‐Vázquez, PhD, Section of Postgraduate Studies and Research, School of Medicine, National Polytechnic Institute, Carlos Palma‐Flores, MD/PhD, National Council for Science and Technology; School of Medicine, National Polytechnic Institute

Skeletal muscle comprises slow and fast-twitch fibers, which differ in molecular composition, function, and systemic energy consumption. In addition, muscular dystrophies, a group of diverse hereditary diseases, present different patterns of muscle involvement, progression, and severity, suggesting that the regeneration-degeneration process may differ depending on the muscle type. Therefore, the study aimed to explore the expression of proteins involved in the repair process in different muscles at an early stage of muscular dystrophy in the δ-sarcoglycan null mice (Sgcd-null), a limb-girdle muscular dystrophy 2F model. Hematoxylin & Eosin (H&E) Staining showed a high number of central nuclei in soleus (Sol), tibialis, gastrocnemius, and extensor digitorum longus from four months Sgcd-null mice. However, fibrosis, determined by trichrome of Gomori modified staining, was only observed in Sgcd-null Sol. In addition, the number of Type I and II fibers variated differentially in the Sgcd-null muscles vs. wild-type muscles. Besides, the protein expression level of β-catenin, myomaker, MyoD, and myogenin also presented different expression levels in all the Sgcd-null muscles studied. In summary, our study reveals that muscles with different metabolic characteristics showed distinct expression patterns of proteins involved in the muscle regeneration process. These results could be relevant in designing therapies for genetic and acquired myopathy.