Hypoxia-inducible factor 1-α induces miR-210 in normoxic differentiating myoblasts

J Biol Chem. 2012 Dec 28;287(53):44761-71. doi: 10.1074/jbc.M112.421255. Epub 2012 Nov 12.

Abstract

MicroRNA-210 (miR-210) induction is a virtually constant feature of the hypoxic response in both normal and transformed cells, regulating several key aspects of cardiovascular diseases and cancer. We found that miR-210 was induced in normoxic myoblasts upon myogenic differentiation both in vitro and in vivo. miR-210 transcription was activated in an hypoxia-inducible factor 1-α (Hif1a)-dependent manner, and chromatin immunoprecipitation experiments show that Hif1a bound to the miR-210 promoter only in differentiated myotubes. Accordingly, luciferase reporter assays demonstrated the functional relevance of the Hif1a binding site for miR-210 promoter activation in differentiating myoblasts. To investigate the functional relevance of increased miR-210 levels in differentiated myofibers, we blocked miR-210 with complementary locked nucleic acid oligonucleotides (anti-miR-210). We found that C2C12 myoblast cell line differentiation was largely unaffected by anti-miR-210. Likewise, miR-210 inhibition did not affect skeletal muscle regeneration following cardiotoxin damage. However, we found that miR-210 blockade greatly increased myotube sensitivity to oxidative stress and mitochondrial dysfunction. In conclusion, miR-210 is induced in normoxic myofibers, playing a cytoprotective role.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cell Differentiation*
  • Cell Line
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Male
  • Mice
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Molecular Sequence Data
  • Myoblasts / cytology*
  • Myoblasts / metabolism*
  • Oxygen / metabolism*
  • Promoter Regions, Genetic

Substances

  • Hif1a protein, mouse
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • MIRN210 microRNA, mouse
  • MicroRNAs
  • Oxygen