The regulation of vascular endothelial growth factors (VEGF-A, -C, and -D) expression in the retinal pigment epithelium

Exp Eye Res. 2006 Nov;83(5):1031-40. doi: 10.1016/j.exer.2006.05.007. Epub 2006 Jul 12.

Abstract

The vascular endothelial growth factor (VEGF) family plays an essential role in vascular development, angiogenesis and lymphangiogenesis. VEGF-A is a key regulator of endothelial cell functions and VEGF-C and VEGF-D are known to stimulate both angiogenesis and lymphangiogenesis. In a surgically removed subretinal vascular membrane of an age-related macular degeneration (AMD) patient, both VEGF-C and VEGF-D were confirmed, in addition to VEGF-A, to be markedly positive in the retinal pigment epithelium (RPE). There is no lymph vessel in ocular tissue, so it is possible that VEGF-C and VEGF-D expression in the RPE play some role in ocular angiogenesis, as well as VEGF-A. Next, we assessed the transition of VEGF-A, -C, and -D expression on several conditions, in human RPE. Hypoxia proverbially induced VEGF-A mRNA expression, meanwhile VEGF-C and VEGF-D mRNA expression was down-regulated. The Ca(2+) deprivation from culture medium strongly up-regulated VEGF-A and VEGF-D mRNA expression. Culture on plastic flasks precoated with poly-2-hydroxyethyl methacrylate up-regulated VEGF-D expression. Meanwhile, no significant change of VEGF-C mRNA expression was found in the blockade of cell-cell and/or cell-matrix adhesion. These findings suggest the possibility that VEGF-C and VEGF-D expression in RPE modify the ocular angiogenesis as angiogenic stimulators.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cell Adhesion / physiology
  • Cell Count
  • Cell Membrane / genetics
  • Cells, Cultured
  • Extracellular Matrix / physiology
  • Eye Proteins / analysis*
  • Female
  • Gene Expression Regulation / genetics*
  • Humans
  • Hypoxia / genetics
  • Immunohistochemistry / methods
  • Macular Degeneration / genetics*
  • Neovascularization, Pathologic / genetics
  • Pigment Epithelium of Eye / physiology*
  • RNA, Messenger / analysis
  • Vascular Endothelial Growth Factor A / analysis
  • Vascular Endothelial Growth Factor C / analysis
  • Vascular Endothelial Growth Factor D / analysis
  • Vascular Endothelial Growth Factors / analysis*

Substances

  • Eye Proteins
  • RNA, Messenger
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factor C
  • Vascular Endothelial Growth Factor D
  • Vascular Endothelial Growth Factors