Regulation of heme oxygenase-1 protein expression by miR-377 in combination with miR-217

J Biol Chem. 2011 Feb 4;286(5):3194-202. doi: 10.1074/jbc.M110.148726. Epub 2010 Nov 24.

Abstract

Heme oxygenase-1 (HO-1) enzyme plays a critical role in metabolizing the excess heme generated during hemolysis. Our previous studies suggested that during intravascular hemolysis the expression of HO-1 protein is not sufficient to reduce the oxidative burden of free heme in the vasculature. This led us to hypothesize that a post-translational mechanism of control exists for HO-1 expression. Micro-RNAs (miRNA) affect gene expression by post-transcriptional gene regulation of transcripts. We performed in silico analysis for the human HMOX1-3' untranslated region (3' UTR) and identified candidate miRNA binding sites. Two candidate miRNAs, miR-377 and miR-217, were cloned and co-transfected with a luciferase vector containing the human HMOX1-3'UTR region. The combination of miR-377 and miR-217 produced a 58% reduction in HMOX1-3'UTR luciferase reporter expression compared with controls. The same constructs were then used to assess how overexpression of miR-217 and miR-377 affected HO-1 levels after induction with hemin. Cells transfected with the combination of miR-377 and miR-217 exhibited no change in HMOX1 mRNA levels, but a significant reduction in HMOX1 (HO-1) protein expression and enzyme activity compared with non-transfected hemin-stimulated controls. Transfection with either miR-377 or miR-217 alone did not produce a significant decrease in HO-1 protein expression or enzyme activity. Knockdown of miR-217 and miR-377 in combination leads to up-regulation of HO-1 protein. Exposure to hemin induced a significant reduction in miR-217 expression and a trend toward decreased miR-377 expression in two different cells lines. In summary, these data suggests that the combination of miR-377 and miR-217 help regulate HO-1 protein expression in the presence of hemin.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Drug Synergism
  • Drug Therapy, Combination
  • Gene Expression Regulation / drug effects*
  • Heme Oxygenase-1 / biosynthesis
  • Heme Oxygenase-1 / genetics*
  • Hemin / pharmacology
  • Humans
  • MicroRNAs / genetics*
  • MicroRNAs / pharmacology
  • Transfection

Substances

  • MIRN217 microRNA, human
  • MIRN377 microRNA, human
  • MicroRNAs
  • Hemin
  • Heme Oxygenase-1