Targeting VE-PTP activates TIE2 and stabilizes the ocular vasculature

J Clin Invest. 2014 Oct;124(10):4564-76. doi: 10.1172/JCI74527. Epub 2014 Sep 2.

Abstract

Retinal and choroidal neovascularization (NV) and vascular leakage contribute to visual impairment in several common ocular diseases. The angiopoietin/TIE2 (ANG/TIE2) pathway maintains vascular integrity, and negative regulators of this pathway are potential therapeutic targets for these diseases. Here, we demonstrated that vascular endothelial-protein tyrosine phosphatase (VE-PTP), which negatively regulates TIE2 activation, is upregulated in hypoxic vascular endothelial cells, particularly in retinal NV. Intraocular injection of an anti-VE-PTP antibody previously shown to activate TIE2 suppressed ocular NV. Furthermore, a small-molecule inhibitor of VE-PTP catalytic activity (AKB-9778) activated TIE2, enhanced ANG1-induced TIE2 activation, and stimulated phosphorylation of signaling molecules in the TIE2 pathway, including AKT, eNOS, and ERK. In mouse models of neovascular age-related macular degeneration, AKB-9778 induced phosphorylation of TIE2 and strongly suppressed NV. Ischemia-induced retinal NV, which is relevant to diabetic retinopathy, was accentuated by the induction of ANG2 but inhibited by AKB-9778, even in the presence of high levels of ANG2. AKB-9778 also blocked VEGF-induced leakage from dermal and retinal vessels and prevented exudative retinal detachments in double-transgenic mice with high expression of VEGF in photoreceptors. These data support targeting VE-PTP to stabilize retinal and choroidal blood vessels and suggest that this strategy has potential for patients with a wide variety of retinal and choroidal vascular diseases.

Publication types

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

MeSH terms

  • Aniline Compounds / pharmacology*
  • Animals
  • Catalysis
  • Cell Hypoxia
  • Choroid / blood supply
  • Eye / blood supply*
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Hypoxia
  • Macular Degeneration
  • Mice
  • Mice, Transgenic
  • Oxygen / metabolism
  • Phosphorylation
  • Receptor, TIE-2 / metabolism*
  • Receptor-Like Protein Tyrosine Phosphatases, Class 3 / metabolism*
  • Retinal Vessels / pathology*
  • Signal Transduction
  • Sulfonic Acids / pharmacology*
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • AKB-9778
  • Aniline Compounds
  • Sulfonic Acids
  • Vascular Endothelial Growth Factor A
  • Receptor, TIE-2
  • Tek protein, mouse
  • Receptor-Like Protein Tyrosine Phosphatases, Class 3
  • Oxygen