title: Differential expression of angioregulatory factors in normal and CNV-derived human retinal pigment epithelium.
abstract: BACKGROUND
  Choroidal neovascularization (CNV) causes loss of vision in age-related macular degeneration (AMD). In CNV, choroidal capillaries penetrate Bruch's membrane and the retinal pigment epithelium (RPE). Angiogenic factors produced by RPE cells are suspected as major contributors to CNV development. We therefore studied the differential expression of angioregulatory factors in normal and CNV-derived RPE.
  
  
  METHODS
  Cultures of normal (ARPE-19) and CNV-derived RPE (CNV-RPE) were compared by quantitative PCR. Differential expression was verified on the protein level by immunohistochemistry in tissue samples.
  
  
  RESULTS
  The angioregulatory factors VEGF-A, VEGF-B, VEGF-C, Angiopoietin-1 (Ang-1) and Angiopoietin-2, Semaphorin-3A, PEDF, HIF-1, FGF-2, and the receptors VEGF-R2, Neuropilin-1 and Neuropilin-2 were detected in both, ARPE-19 and CNV-RPE. Transcription of PEDF, FGF-2, Neuropilin-2, Ang-1 and Ang-2 was significantly upregulated in CNV-RPE. EphA7, VEGF-R1 and leptin were transcribed exclusively in CNV-RPE and Eph-A7 and VEGF-R1 proteins were present exclusively in CNV specimens.
  
  
  CONCLUSIONS
  A set of common factors controlling angiogenesis was detected in both, ARPE-19 cells and CNV-RPE cells. Surprisingly, PEDF and other factors inhibiting angiogenesis are strongly upregulated in CNV-RPE; thus, at least in later stages, the RPE has a potential to control angiogenesis in age-related macular degeneration.
authors.affiliation: Universitaets-Augenklinik Freiburg, Killianstrasse 5, 79106, Freiburg, Germany.
authors.forename: Gottfried
authors.initials: G
authors.lastname: Martin
authors.forename: Günther
authors.initials: G
authors.lastname: Schlunck
authors.forename: Lutz L
authors.initials: LL
authors.lastname: Hansen
authors.forename: Hansjürgen T
authors.initials: HT
authors.lastname: Agostini
mesh_terms: D042501:Angiogenic Proteins / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D020256:Choroidal Neovascularization / Q000378:metabolism* / Q000473:pathology; D017931:DNA Primers / Q000737:chemistry; D005786:Gene Expression Regulation / Q000502:physiology*; D006133:Growth Substances / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D010857:Pigment Epithelium of Eye / Q000378:metabolism* / Q000473:pathology; D016133:Polymerase Chain Reaction; D015854:Up-Regulation
chemical_list: D042501:Angiogenic Proteins; D017931:DNA Primers; D006133:Growth Substances