Inhibition of miR-92a increases endothelial proliferation and migration in vitro as well as reduces neointimal proliferation in vivo after vascular injury

Basic Res Cardiol. 2012 Sep;107(5):296. doi: 10.1007/s00395-012-0296-y. Epub 2012 Aug 14.

Abstract

The role of miR-92a on vascular remodelling after injury is currently unknown. Thus, the aim of the present study was to evaluate the role of miR-92a on rat endothelial and vascular smooth muscle cells proliferation and migration in vitro as well as after balloon injury or arterial stenting in vivo. MiR-92a was highly expressed in RAO-ECs and vascular endothelium, but not in RAO-SMCs or medial smooth muscle as assessed by real-time RT-PCR. Importantly, BrdU incorporation and wound healing assay provide evidence that functional inhibition of miR-92a resulted in an increased RAO-ECs proliferation and migration, but had no effect on RAO-SMCs proliferation or migration in vitro. Immunoblotting analysis revealed an increased phosphorylation of ERK1/2, JNK/SAPK as well as eNOS and phospho-eNOS increased expression level in RAO-ECs as a consequence of miR-92a inhibition. Using gain and loss of function experiments, we showed that miR-92a modulates regulation of KLF4 and MKK4 expression level in endothelial cells. Finally, in vivo administration of antagomiR-92a significantly enhanced re-endothelialization in injured carotid arteries and reduced neointimal formation after balloon injury or arterial stenting. These data provide the first evidence that inhibition of miR-92a may represent a novel strategy to improve endothelial regeneration and reduce restenosis after vascular injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Movement*
  • Cell Proliferation*
  • Cells, Cultured
  • Endothelial Cells / physiology*
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Humans
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • Kruppel-Like Factor 4
  • Kruppel-Like Transcription Factors / genetics
  • MAP Kinase Kinase 4 / genetics
  • Male
  • MicroRNAs / analysis
  • MicroRNAs / antagonists & inhibitors
  • MicroRNAs / physiology*
  • Muscle, Smooth, Vascular / cytology
  • Neointima / prevention & control*
  • Nitric Oxide / biosynthesis
  • Rats
  • Rats, Wistar
  • Vascular System Injuries / pathology*
  • von Willebrand Factor / analysis

Substances

  • KLF4 protein, human
  • Klf4 protein, rat
  • Kruppel-Like Factor 4
  • Kruppel-Like Transcription Factors
  • MIRN92 microRNA, human
  • MicroRNAs
  • von Willebrand Factor
  • Nitric Oxide
  • Extracellular Signal-Regulated MAP Kinases
  • JNK Mitogen-Activated Protein Kinases
  • MAP Kinase Kinase 4
  • MAP2K4 protein, human