Identification of cyclins A1, E1 and vimentin as downstream targets of heme oxygenase-1 in vascular endothelial growth factor-mediated angiogenesis

Sci Rep. 2016 Jul 8:6:29417. doi: 10.1038/srep29417.

Abstract

Angiogenesis is an essential physiological process and an important factor in disease pathogenesis. However, its exploitation as a clinical target has achieved limited success and novel molecular targets are required. Although heme oxygenase-1 (HO-1) acts downstream of vascular endothelial growth factor (VEGF) to modulate angiogenesis, knowledge of the mechanisms involved remains limited. We set out identify novel HO-1 targets involved in angiogenesis. HO-1 depletion attenuated VEGF-induced human endothelial cell (EC) proliferation and tube formation. The latter response suggested a role for HO-1 in EC migration, and indeed HO-1 siRNA negatively affected directional migration of EC towards VEGF; a phenotype reversed by HO-1 over-expression. EC from Hmox1(-/-) mice behaved similarly. Microarray analysis of HO-1-depleted and control EC exposed to VEGF identified cyclins A1 and E1 as HO-1 targets. Migrating HO-1-deficient EC showed increased p27, reduced cyclin A1 and attenuated cyclin-dependent kinase 2 activity. In vivo, cyclin A1 siRNA inhibited VEGF-driven angiogenesis, a response reversed by Ad-HO-1. Proteomics identified structural protein vimentin as an additional VEGF-HO-1 target. HO-1 depletion inhibited VEGF-induced calpain activity and vimentin cleavage, while vimentin silencing attenuated HO-1-driven proliferation. Thus, vimentin and cyclins A1 and E1 represent VEGF-activated HO-1-dependent targets important for VEGF-driven angiogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiogenesis Inducing Agents / pharmacology*
  • Animals
  • Apoptosis / drug effects
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cyclin A1 / genetics*
  • Cyclin E / genetics*
  • Cyclin-Dependent Kinase 2 / metabolism
  • Embryonic Stem Cells / cytology*
  • Embryonic Stem Cells / drug effects
  • Embryonic Stem Cells / metabolism
  • Heme Oxygenase-1 / genetics*
  • Heme Oxygenase-1 / metabolism
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Mice
  • Proteomics
  • Vascular Endothelial Growth Factor A / pharmacology*
  • Vimentin / genetics*

Substances

  • Angiogenesis Inducing Agents
  • Cyclin A1
  • Cyclin E
  • Vascular Endothelial Growth Factor A
  • Vimentin
  • Heme Oxygenase-1
  • Cyclin-Dependent Kinase 2