Transdifferentiated retinal pigment epithelial cells are immunoreactive for vascular endothelial growth factor in surgically excised age-related macular degeneration-related choroidal neovascular membranes

Invest Ophthalmol Vis Sci. 1996 Apr;37(5):855-68.


Purpose: To determine the cellular origin and the vascular endothelial growth factor (VEGF) immunoreactivity of the nonvascular stromal cells in surgically excised age-related macular degeneration (ARMD)-associated choroidal neovascular membranes (CNVMs).

Methods: Immunohistochemical analysis was performed on frozen sections of eight surgically excised ARMD-related CNVMs.

Results: Cytokeratin-positive, smooth muscle actin-positive polygonal or fibroblastic (transdifferentiated RPE) cells were the principal nonvascular stromal cells detected. The polygonal cells were more commonly found in active (highly vascularized) regions and were strongly immunoreactive for VEGF. The fibroblastic cells were predominantly found in fibrotic (hypovascular) regions and were minimally immunoreactive for VEGF.

Conclusions: Transdifferentiated RPE cells are the principal nonvascular stromal cells of both vascular and fibrotic ARMD-related CNVMs. Preferential localization of VEGF immunoreactivity with the cytoplasm of the polygonal transdifferentiated RPE cells in the highly vascularized regions of the surgically excised CNVMs suggests an important angiogenic role of these cells and this growth factor in the progression of ARMD-related choroidal neovascularization.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actins / metabolism
  • Aged
  • Aged, 80 and over
  • Antibodies, Monoclonal
  • Cell Differentiation
  • Choroid / blood supply*
  • Choroid / surgery
  • Endothelial Growth Factors / analysis*
  • Endothelial Growth Factors / immunology
  • Female
  • Fluorescent Antibody Technique
  • Glial Fibrillary Acidic Protein / metabolism
  • Humans
  • Immunoenzyme Techniques
  • Keratins / metabolism
  • Lymphokines / analysis*
  • Lymphokines / immunology
  • Macular Degeneration / complications*
  • Male
  • Neovascularization, Pathologic / etiology
  • Neovascularization, Pathologic / metabolism*
  • Neovascularization, Pathologic / pathology
  • Neovascularization, Pathologic / surgery
  • Pigment Epithelium of Eye / chemistry*
  • Pigment Epithelium of Eye / immunology
  • Pigment Epithelium of Eye / pathology
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors


  • Actins
  • Antibodies, Monoclonal
  • Endothelial Growth Factors
  • Glial Fibrillary Acidic Protein
  • Lymphokines
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors
  • Keratins