Roles of HIFs and VEGF in angiogenesis in the retina and brain

J Clin Invest. 2019 Aug 12;129(9):3807-3820. doi: 10.1172/JCI126655.


Vascular development in the mammalian retina is a paradigm for CNS vascular development in general, and its study is revealing fundamental mechanisms that explain the efficacy of antiangiogenic therapies in retinal vascular disease. During development of the mammalian retina, hypoxic astrocytes are hypothesized to secrete VEGF, which attracts growing endothelial cells as they migrate radially from the optic disc. However, published tests of this model using astrocyte-specific deletion of Vegf in the developing mouse retina appear to contradict this theory. Here, we report that selectively eliminating Vegf in neonatal retinal astrocytes with a Gfap-Cre line that recombines with approximately 100% efficiency had no effect on proliferation or radial migration of astrocytes, but completely blocked radial migration of endothelial cells, strongly supporting the hypoxic astrocyte model. Using additional Cre driver lines, we found evidence for essential and partially redundant actions of retina-derived (paracrine) and astrocyte-derived (autocrine) VEGF in controlling astrocyte proliferation and migration. We also extended previous studies by showing that HIF-1α in retinal neurons and HIF-2α in Müller glia play distinct roles in retinal vascular development and disease, adding to a growing body of data that point to the specialization of these 2 hypoxia-sensing transcription factors.

Keywords: Development; Vascular Biology; endothelial cells.

Publication types

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

MeSH terms

  • Animals
  • Astrocytes / metabolism
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Brain / blood supply
  • Brain / metabolism*
  • Cell Movement
  • Cell Proliferation
  • Cerebral Cortex / metabolism
  • Endothelial Cells / metabolism
  • Genotype
  • Green Fluorescent Proteins / metabolism
  • Hypoxia
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Mice
  • Neovascularization, Physiologic*
  • Phenotype
  • Retina / metabolism*
  • Retinal Vessels / growth & development
  • Vascular Endothelial Growth Factor A / metabolism*


  • Basic Helix-Loop-Helix Transcription Factors
  • Hif1a protein, mouse
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Vascular Endothelial Growth Factor A
  • vascular endothelial growth factor A, mouse
  • Green Fluorescent Proteins
  • endothelial PAS domain-containing protein 1