title: Effect of VEGF and anti-VEGF compounds on retinal pigment epithelium permeability: an in vitro study.
abstract: OBJECTIVE
  To evaluate the effect of 2 vascular endothelial growth factor (VEGF) isoforms (121 and 165) and 2 anti-VEGF compounds (ranibizumab and pegaptanib sodium) on the permeability of human retinal pigment epithelium (RPE) cells in vitro.
  
  
  METHODS
  The RPE permeability was assessed on ARPE19 cells grown onto inserts of polytetrafluoroethylene previously treated with ammonia gas plasma. Paracellular permeability to ions was measured by mean of transepithelial electrical resistance (TEER). Permeability to non-ionic molecules was gathered by the amount of fluorescein dextran (FD) passing across the monolayer within 2 hours.
  
  
  RESULTS
  Only VEGF165 applied at the apical side of the monolayer induced a statistically significant decrease of TEER (p<0.001). No changes in TEER were observed when pegaptanib sodium or ranibizumab were apically administered together with VEGF165.  Both VEGF isoforms significantly increased permeability to 4 kDa dextran (p<0.01). Apical administration of ranibizumab or pegaptanib sodium as well as coadministration of pegaptanib sodium with VEGF121 or VEGF165 induced a statistically significant increase of permeability to 4 kDa FD.
  
  
  CONCLUSIONS
  Both VEGF isoforms and anti-VEGF compounds exert an effect on human RPE permeability in vitro.
authors.affiliation: St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom. claudio.campa@yahoo.com
authors.forename: Claudio
authors.initials: C
authors.lastname: Campa
mesh_terms: D000704:Analysis of Variance; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized / Q000494:pharmacology*; D052157:Aptamers, Nucleotide / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects*; D002478:Cells, Cultured; D017097:Electric Impedance; D006801:Humans; D000069579:Ranibizumab; D055213:Retinal Pigment Epithelium / Q000187:drug effects*; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors* / Q000494:pharmacology
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D052157:Aptamers, Nucleotide; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C495058:pegaptanib; D000069579:Ranibizumab