AIP1 mediates vascular endothelial cell growth factor receptor-3-dependent angiogenic and lymphangiogenic responses

Arterioscler Thromb Vasc Biol. 2014 Mar;34(3):603-15. doi: 10.1161/ATVBAHA.113.303053. Epub 2014 Jan 9.

Abstract

Objective: To investigate the novel function of ASK1-interacting protein-1 (AIP1) in vascular endothelial cell growth factor receptor (VEGFR)-3 signaling, and VEGFR-3-dependent angiogenesis and lymphangiogenesis.

Approach and results: AIP1, a signaling scaffold protein, is highly expressed in the vascular endothelium. We have previously reported that AIP1 functions as an endogenous inhibitor in pathological angiogenesis by blocking VEGFR-2 activity. Surprisingly, here we observe that mice with a global deletion of AIP1-knockout mice (AIP1-KO) exhibit reduced retinal angiogenesis with less sprouting and fewer branches. Vascular endothelial cell (but not neuronal)-specific deletion of AIP1 causes similar defects in retinal angiogenesis. The reduced retinal angiogenesis correlates with reduced expression in VEGFR-3 despite increased VEGFR-2 levels in AIP1-KO retinas. Consistent with the reduced expression of VEGFR-3, AIP1-KO show delayed developmental lymphangiogenesis in neonatal skin and mesentery, and mount weaker VEGF-C-induced cornea lymphangiogenesis. In vitro, human lymphatic endothelial cells with AIP1 small interfering RNA knockdown, retinal endothelial cells, and lymphatic endothelial cells isolated from AIP1-KO all show attenuated VEGF-C-induced VEGFR-3 signaling. Mechanistically, we demonstrate that AIP1 via vegfr-3-specific miR-1236 increases VEGFR-3 protein expression and that, by directly binding to VEGFR-3, it enhances VEGFR-3 endocytosis and stability.

Conclusion: Our in vivo and in vitro results provide the first insight into the mechanism by which AIP1 mediates VEGFR-3-dependent angiogenic and lymphangiogenic signaling.

Keywords: DAB2IP protein, human; lymphangiogenesis; vascular endothelial growth factor A; vascular endothelial growth factor receptor-2; vascular endothelial growth factor receptor-3.

Publication types

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

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Animals
  • Carrier Proteins / antagonists & inhibitors
  • Carrier Proteins / genetics
  • Carrier Proteins / physiology*
  • Cells, Cultured
  • Cornea
  • Endocytosis
  • Endothelial Cells / metabolism
  • Endothelium, Vascular / metabolism
  • Endothelium, Vascular / pathology
  • Eye Proteins / physiology
  • Guanylate Kinases
  • Humans
  • Lymphangiogenesis / physiology*
  • Mice
  • Mice, Knockout
  • MicroRNAs / physiology
  • Neurons / metabolism
  • RNA Interference
  • RNA, Small Interfering / pharmacology
  • Receptors, Notch / physiology
  • Recombinant Proteins / pharmacology
  • Retinal Neovascularization / physiopathology*
  • Vascular Endothelial Growth Factor C / genetics
  • Vascular Endothelial Growth Factor C / pharmacology
  • Vascular Endothelial Growth Factor Receptor-2 / antagonists & inhibitors
  • Vascular Endothelial Growth Factor Receptor-2 / physiology
  • Vascular Endothelial Growth Factor Receptor-3 / biosynthesis
  • Vascular Endothelial Growth Factor Receptor-3 / genetics
  • Vascular Endothelial Growth Factor Receptor-3 / physiology*
  • ras GTPase-Activating Proteins / deficiency
  • ras GTPase-Activating Proteins / genetics
  • ras GTPase-Activating Proteins / physiology*

Substances

  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • Dab2ip protein, mouse
  • Eye Proteins
  • MicroRNAs
  • Mirn1236 microRNA, mouse
  • RNA, Small Interfering
  • Receptors, Notch
  • Recombinant Proteins
  • Vascular Endothelial Growth Factor C
  • ras GTPase-Activating Proteins
  • Vascular Endothelial Growth Factor Receptor-2
  • Vascular Endothelial Growth Factor Receptor-3
  • Guanylate Kinases
  • MAGI2 protein, human