The FSHD atrophic myotube phenotype is caused by DUX4 expression

PLoS One. 2011;6(10):e26820. doi: 10.1371/journal.pone.0026820. Epub 2011 Oct 28.


Background: Facioscapulohumeral muscular dystrophy (FSHD) is linked to deletions in 4q35 within the D4Z4 repeat array in which we identified the double homeobox 4 (DUX4) gene. We found stable DUX4 mRNAs only derived from the most distal D4Z4 unit and unexpectedly extended to the flanking pLAM region that provided an intron and a polyadenylation signal. DUX4 encodes a transcription factor expressed in FSHD but not control primary myoblasts or muscle biopsies. The DUX4 protein initiates a large transcription deregulation cascade leading to muscle atrophy and oxidative stress, which are FSHD key features.

Methodology/principal findings: We now show that transfection of myoblasts with a DUX4 expression vector leads to atrophic myotube formation associated with the induction of E3 ubiquitin ligases (MuRF1 and Atrogin1/MAFbx) typical of muscle atrophy. DUX4 induces expression of downstream targets deregulated in FSHD such as mu-crystallin and TP53. We developed specific siRNAs and antisense oligonucleotides (AOs) targeting the DUX4 mRNA. Addition of these antisense agents to primary FSHD myoblast cultures suppressed DUX4 protein expression and affected expression of the above-mentioned markers.

Conclusions/significance: These results constitute a proof of concept for the development of therapeutic approaches for FSHD targeting DUX4 expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomarkers / metabolism
  • Cells, Cultured
  • Down-Regulation / drug effects
  • Gene Expression Regulation / drug effects
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • Humans
  • Mice
  • Models, Biological
  • Muscle Fibers, Skeletal / drug effects
  • Muscle Fibers, Skeletal / metabolism*
  • Muscle Fibers, Skeletal / pathology*
  • Muscle Proteins / metabolism
  • Muscular Atrophy / metabolism*
  • Muscular Atrophy / pathology*
  • Muscular Dystrophy, Facioscapulohumeral / metabolism*
  • Muscular Dystrophy, Facioscapulohumeral / pathology*
  • Oligonucleotides, Antisense / pharmacology
  • Phenotype
  • RNA Interference / drug effects
  • RNA Splicing / drug effects
  • RNA Splicing / genetics
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / metabolism
  • SKP Cullin F-Box Protein Ligases / metabolism
  • Transfection
  • Tripartite Motif Proteins
  • Ubiquitin-Protein Ligases / metabolism


  • Biomarkers
  • DUX4L1 protein, human
  • Homeodomain Proteins
  • Muscle Proteins
  • Oligonucleotides, Antisense
  • RNA, Messenger
  • RNA, Small Interfering
  • Tripartite Motif Proteins
  • FBXO32 protein, human
  • SKP Cullin F-Box Protein Ligases
  • TRIM63 protein, human
  • Ubiquitin-Protein Ligases