Girdin and its phosphorylation dynamically regulate neonatal vascular development and pathological neovascularization in the retina

Am J Pathol. 2013 Feb;182(2):586-96. doi: 10.1016/j.ajpath.2012.10.012. Epub 2012 Nov 27.

Abstract

Vascular endothelial growth factor (VEGF) is recognized as a principal mediator of vessel growth. VEGF regulates various endothelial cellular processes, including cell migration, proliferation, and survival, through the serine threonine protein kinase Akt. The Akt substrate girdin, an actin-binding protein, is known to regulate VEGF-mediated postnatal angiogenesis. However, the role of girdin and its phosphorylation in neonatal retinal vascular development and ocular pathological neovascularization in vivo has not been elucidated. In the present study, therefore, we investigated these processes using Girdin(+/-) mice lacking one copy of the girdin gene and girdin S1416A knockin (Girdin-KI(SA/SA)) mice in which the phosphorylation site of girdin is completely disrupted. We used three mouse models of pathological ocular neovascularization: oxygen-induced retinopathy (a mouse model of ischemic retinopathies), laser-induced choroidal neovascularization, and a human VEGF transgenic mouse that overexpresses human VEGF specifically in photoreceptor cells and generates pathological neovascularization in the retina. Neonatal vascular development was delayed and pathological neovascularization was decreased in both Girdin(+/-) mice and Girdin-KI(SA/SA) mice. These results demonstrate that girdin and its phosphorylation play an important role in neonatal vascular development and in pathological neovascularization in the retina.

MeSH terms

  • Animals
  • Animals, Newborn
  • Blood Vessels / drug effects
  • Blood Vessels / growth & development*
  • Blood Vessels / metabolism
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Chromones / pharmacology
  • Disease Models, Animal
  • Female
  • Gene Knockdown Techniques
  • Human Umbilical Vein Endothelial Cells / drug effects
  • Human Umbilical Vein Endothelial Cells / metabolism
  • Humans
  • Mice
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism*
  • Morpholines / pharmacology
  • Neovascularization, Physiologic* / drug effects
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphorylation / drug effects
  • Protein Transport / drug effects
  • Proto-Oncogene Proteins c-akt / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / metabolism
  • Retina / drug effects
  • Retina / metabolism
  • Retina / pathology
  • Retinal Neovascularization / metabolism
  • Retinal Neovascularization / pathology*
  • Signal Transduction / drug effects
  • Vascular Endothelial Growth Factor A / metabolism
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / metabolism*

Substances

  • CCDC88A protein, human
  • Chromones
  • Microfilament Proteins
  • Morpholines
  • RNA, Messenger
  • RNA, Small Interfering
  • Vascular Endothelial Growth Factor A
  • Vesicular Transport Proteins
  • girdin protein, mouse
  • 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt