Transcriptional factors associated with epithelial-mesenchymal transition in choroidal neovascularization

Mol Vis. 2011;17:1222-30. Epub 2011 May 6.

Abstract

Purpose: To investigate the transcriptional factors associated with epithelial-mesenchymal transition (EMT) in choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD).

Methods: Paraffin sections of CNV obtained from patients with AMD (n = 12) were stained for transcriptional factors related to EMT, i.e., Snail, Slug, SIP1, and Twist. As a control, postmortem sections of ocular normal tissue were used. Furthermore, using a human retinal pigment epithelial (RPE) cell line (ARPE-19), reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence microscopy were performed to explore the cellular localization and expression levels of EMT-associated transcriptional factors upon cytokine stimulation.

Results: Of 12 specimens, 11 CNV tissues (91.6%) showed staining for Snail localized in cellular nuclei, particularly in those of RPE cells. Snail was strongly co-localized with α-smooth muscle antigen (SMA) in RPE cells. In contrast, postmortem human retina showed no Snail staining in RPE cells. Other transcriptional factors, Slug, Twist and SIP1 were not detected in CNV or normal human retina. In ARPE-19 cells, RT-PCR and immunofluorescence microscopy showed that Snail mRNA was upregulated by transforming growth factor (TGF)-β and VEGF stimulation. Furthermore, TGF-β induced relocalization of Snail to the nucleus in RPE cells.

Conclusions: The current data indicate that Snail is a major transcriptional factor for EMT changes of RPE cells in human CNV.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cell Line
  • Choroidal Neovascularization / etiology
  • Choroidal Neovascularization / genetics*
  • Epithelial-Mesenchymal Transition / genetics*
  • Female
  • Gene Expression / drug effects
  • Humans
  • Immunohistochemistry
  • Macular Degeneration / complications
  • Macular Degeneration / genetics*
  • Male
  • Microtomy
  • Middle Aged
  • Paraffin Embedding
  • Retina
  • Reverse Transcriptase Polymerase Chain Reaction
  • Snail Family Transcription Factors
  • Transcription Factors* / genetics
  • Transcription Factors* / metabolism
  • Transforming Growth Factor beta / pharmacology
  • Vascular Endothelial Growth Factor A / pharmacology

Substances

  • SNAI1 protein, human
  • Snail Family Transcription Factors
  • Transcription Factors
  • Transforming Growth Factor beta
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A