Histological Methods to Assess Skeletal Muscle Degeneration and Regeneration in Duchenne Muscular Dystrophy

Int J Mol Sci. 2022 Dec 16;23(24):16080. doi: 10.3390/ijms232416080.

Abstract

Duchenne muscular dystrophy (DMD) is a progressive disease caused by the loss of function of the protein dystrophin. This protein contributes to the stabilisation of striated cells during contraction, as it anchors the cytoskeleton with components of the extracellular matrix through the dystrophin-associated protein complex (DAPC). Moreover, absence of the functional protein affects the expression and function of proteins within the DAPC, leading to molecular events responsible for myofibre damage, muscle weakening, disability and, eventually, premature death. Presently, there is no cure for DMD, but different treatments help manage some of the symptoms. Advances in genetic and exon-skipping therapies are the most promising intervention, the safety and efficiency of which are tested in animal models. In addition to in vivo functional tests, ex vivo molecular evaluation aids assess to what extent the therapy has contributed to the regenerative process. In this regard, the later advances in microscopy and image acquisition systems and the current expansion of antibodies for immunohistological evaluation together with the development of different spectrum fluorescent dyes have made histology a crucial tool. Nevertheless, the complexity of the molecular events that take place in dystrophic muscles, together with the rise of a multitude of markers for each of the phases of the process, makes the histological assessment a challenging task. Therefore, here, we summarise and explain the rationale behind different histological techniques used in the literature to assess degeneration and regeneration in the field of dystrophinopathies, focusing especially on those related to DMD.

Keywords: Duchenne muscular dystrophy; animal model; degeneration; dystrophin; histology; immunofluorescence; immunohistology; myofibre; regeneration; skeletal muscle.

Publication types

  • Review

MeSH terms

  • Animals
  • Disease Models, Animal
  • Dystrophin / genetics
  • Dystrophin / metabolism
  • Muscle, Skeletal / metabolism
  • Muscular Dystrophy, Duchenne* / genetics

Substances

  • Dystrophin

Grants and funding

This work was supported by grants from the Belgian Telethon (ABMM), the French Association against Myopathies (AFM Téléthon) and the Fund for Scientific Research FNRS (PDR/T.0026.21). M.A.-S. is Chargé de Recherches and N.D. Spécialiste Doctorant of the FNRS. C.M.S. has received a fellowship from the FRIA. M.A.D.-L.d.C. received fellowships from the EMBO, the VI Plan Propio from the University of Seville and the Wallonie-Bruxelles International Excellence Program.