HDAC4-myogenin axis as an important marker of HD-related skeletal muscle atrophy

PLoS Genet. 2015 Mar 6;11(3):e1005021. doi: 10.1371/journal.pgen.1005021. eCollection 2015 Mar.

Abstract

Skeletal muscle remodelling and contractile dysfunction occur through both acute and chronic disease processes. These include the accumulation of insoluble aggregates of misfolded amyloid proteins that is a pathological feature of Huntington's disease (HD). While HD has been described primarily as a neurological disease, HD patients' exhibit pronounced skeletal muscle atrophy. Given that huntingtin is a ubiquitously expressed protein, skeletal muscle fibres may be at risk of a cell autonomous HD-related dysfunction. However the mechanism leading to skeletal muscle abnormalities in the clinical and pre-clinical HD settings remains unknown. To unravel this mechanism, we employed the R6/2 transgenic and HdhQ150 knock-in mouse models of HD. We found that symptomatic animals developed a progressive impairment of the contractile characteristics of the hind limb muscles tibialis anterior (TA) and extensor digitorum longus (EDL), accompanied by a significant loss of motor units in the EDL. In symptomatic animals, these pronounced functional changes were accompanied by an aberrant deregulation of contractile protein transcripts and their up-stream transcriptional regulators. In addition, HD mouse models develop a significant reduction in muscle force, possibly as a result of a deterioration in energy metabolism and decreased oxidation that is accompanied by the re-expression of the HDAC4-DACH2-myogenin axis. These results show that muscle dysfunction is a key pathological feature of HD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Atrophy
  • Gene Knock-In Techniques
  • Histone Deacetylases / metabolism
  • Humans
  • Huntington Disease / genetics
  • Huntington Disease / metabolism
  • Huntington Disease / pathology*
  • Mice
  • Mice, Transgenic
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / pathology*
  • Myogenin / metabolism
  • Serotonin Plasma Membrane Transport Proteins / metabolism

Substances

  • Myogenin
  • Serotonin Plasma Membrane Transport Proteins
  • Slc6a4 protein, mouse
  • Hdac5 protein, mouse
  • Histone Deacetylases

Grants and funding

This work was supported by the CHDI Foundation, a not-for-profit biomedical research organization exclusively dedicated to discovering and developing therapeutics that slow the progression of Huntington's disease. Research conducted at King's College London was performed in collaboration with and funded by the CHDI Foundation. Part of this work was funded by the Princes Beatrix Fonds Scholarship SC-11-06, National Science Centre of Poland (2011/01/B/NZ4/03719) and Foundation for Polish Science (TEAM/2011-8/7). These funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.