Inhibition of APE1/Ref-1 redox activity with APX3330 blocks retinal angiogenesis in vitro and in vivo

Vision Res. 2011 Jan;51(1):93-100. doi: 10.1016/j.visres.2010.10.008. Epub 2010 Oct 14.


This study examines the role of APE1/Ref-1 in the retina and its potential as a therapeutic target for inhibiting retinal angiogenesis. APE1/Ref-1 expression was quantified by Western blot. The role of APE1/Ref-1 redox function in endothelial cell in vitro angiogenesis was examined by treating retinal vascular endothelial cells (RVECs) with APX3330, a small molecule inhibitor of APE1/Ref-1 redox activity. In vitro methods included a proliferation assay, a transwell migration assay, a Matrigel tube formation assay, and a Real-Time Cell Analysis (RTCA) using the xCELLigence System. In vivo functional studies of APE1/Ref-1 were carried out by treating very low density lipoprotein (VLDL) receptor knockout mice (Vldlr(-/-)) with intravitreal injection of APX3330, and subsequent measurement of retinal angiomatous proliferation (RAP)-like neovascularization for one week. APE1/Ref-1 was highly expressed in the retina and in RVECs and pericytes in mice. APX3330 (1-10 μM) inhibited proliferation, migration and tube formation of RVECs in vitro in a dose-dependent manner. Vldlr(-/-) RVECs were more sensitive to APX3330 than wild-type RVECs. In Vldlr(-/-) mice, a single intravitreal injection of APX3330 at the onset of RAP-like neovascularization significantly reduced RAP-like neovascularization development. APE1/Ref-1 is expressed in retinal vascular cells. APX3330 inhibits RVEC angiogenesis in vitro and significantly reduces RAP-like neovascularization in Vldlr(-/-) mice. These data support the conclusion that APE1/Ref-1 redox function is required for retinal angiogenesis. Thus, APE1/Ref-1 may have potential as a therapeutic target for treating neovascular age-related macular degeneration and other neovascular diseases.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Benzoquinones / pharmacology*
  • Blotting, Western
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • DNA-(Apurinic or Apyrimidinic Site) Lyase / antagonists & inhibitors
  • DNA-(Apurinic or Apyrimidinic Site) Lyase / metabolism*
  • Endothelium, Vascular / drug effects*
  • Endothelium, Vascular / metabolism*
  • Mice
  • Mice, Knockout
  • Neovascularization, Pathologic / drug therapy
  • Neovascularization, Pathologic / metabolism*
  • Oxidation-Reduction
  • Propionates
  • Retina / drug effects*
  • Retina / metabolism*
  • Retinal Neovascularization / drug therapy
  • Retinal Neovascularization / metabolism*


  • Benzoquinones
  • Propionates
  • E 3330
  • APEX1 protein, human
  • DNA-(Apurinic or Apyrimidinic Site) Lyase