N-acetyl-L-cysteine prevents stress-induced desmin aggregation in cellular models of desminopathy

PLoS One. 2013 Oct 1;8(10):e76361. doi: 10.1371/journal.pone.0076361. eCollection 2013.

Abstract

Mutations within the human desmin gene are responsible for a subcategory of myofibrillar myopathies called desminopathies. However, a single inherited mutation can produce different phenotypes within a family, suggesting that environmental factors influence disease states. Although several mouse models have been used to investigate organ-specific desminopathies, a more general mechanistic perspective is required to advance our knowledge toward patient treatment. To improve our understanding of disease pathology, we have developed cellular models to observe desmin behaviour in early stages of disease pathology, e.g., upon formation of cytoplasmic desmin aggregates, within an isogenic background. We cloned the wildtype and three mutant desmin cDNAs using a Tet-On Advanced® expression system in C2C12 cells. Mutations were selected based on positioning within desmin and capacity to form aggregates in transient experiments, as follows: DesS46Y (head domain; low aggregation), DesD399Y (central rod domain; high aggregation), and DesS460I (tail domain; moderate aggregation). Introduction of these proteins into a C2C12 background permitted us to compare between desmin variants as well as to determine the role of external stress on aggregation. Three different types of stress, likely encountered during muscle activity, were introduced to the cell models-thermal (heat shock), redox-associated (H2O2 and cadmium chloride), and mechanical (stretching) stresses-after which aggregation was measured. Cells containing variant DesD399Y were more sensitive to stress, leading to marked cytoplasmic perinuclear aggregations. We then evaluated the capacity of biochemical compounds to prevent this aggregation, applying dexamethasone (an inducer of heat shock proteins), fisetin or N-acetyl-L-cysteine (antioxidants) before stress induction. Interestingly, N-acetyl-L-cysteine pre-treatment prevented DesD399Y aggregation during most stress. N-acetyl-L-cysteine has recently been described as a promising antioxidant in myopathies linked to selenoprotein N or ryanodin receptor defects. Our findings indicate that this drug warrants further study in animal models to speed its potential development as a therapy for DesD399Y-linked desminopathies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcysteine / metabolism*
  • Acetylcysteine / pharmacology
  • Animals
  • Cardiomyopathies / genetics
  • Cardiomyopathies / metabolism*
  • Cell Line
  • Codon
  • Cytoskeleton / genetics
  • Cytoskeleton / metabolism
  • Desmin / genetics
  • Desmin / metabolism*
  • Disease Models, Animal
  • Endoplasmic Reticulum Stress
  • Gene Expression
  • Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / metabolism
  • Humans
  • Mice
  • Muscular Dystrophies / genetics
  • Muscular Dystrophies / metabolism*
  • Mutation
  • Protein Binding
  • Stress, Physiological* / drug effects

Substances

  • Codon
  • Desmin
  • Heat-Shock Proteins
  • Acetylcysteine

Supplementary concepts

  • Myopathy, Myofibrillar, Desmin-Related

Grants and funding

This work was supported by “Université Paris Diderot” (http://www.univ-paris-diderot.fr), the “Centre National de la Recherche Scientifique” (CNRS, http://www.cnrs.fr), and grants from the “Association Française contre les Myopathies” (AFM N°15454; http://www.afm-telethon.fr). The authors are also grateful for financial support from the “rare diseases program” of the National Research Agency (ANR,http://www.agence-nationale-recherche.fr). BDS was supported by a fellowship from the “ministère de la recherche et de l'enseignement supérieur” and AFM. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.