title: Interaction between VEGF and calcium-independent phospholipase A2 in proliferation and migration of retinal pigment epithelium.
abstract: OBJECTIVE
  Inhibition of VEGF in the eye is an important treatment modality for reducing proliferation and migration of retinal pigment epithelium (RPE) in age-related macular degeneration (AMD). Additionally, previous studies suggest calcium-independent phospholipase A(2) group VIA (iPLA(2)-VIA) to be a potential regulator of cell proliferation and migration, and evidence show abundant expression of iPLA(2)-VIA in RPE cells. The aim of the present study was to evaluate the potential role of iPLA(2)-VIA in VEGF-induced proliferation and migration of RPE cells.
  
  
  METHODS
  The human RPE cell line, ARPE-19, was used in all assays. To explore the role of iPLA(2)-VIA in VEGF-induced RPE proliferation and migration, iPLA(2)-VIA inhibition by the iPLA(2)-VIA specific inhibitor, bromoenol lactone, was done. RPE cell proliferation and migration were evaluated by measurements of incorporated radioactive thymidine in DNA and by a Boyden chamber technique, respectively. A luciferase assay monitored the VEGF-induced iPLA(2)-VIA transcriptional activity. Western blot analysis and an activity assay were used to detect the protein levels and activity of iPLA(2)-VIA respectively after treatment with VEGF.
  
  
  RESULTS
  RPE cells treated with VEGF showed significant increased proliferation and migration. Furthermore, inhibition of iPLA(2)-VIA significantly reduced the spontaneous proliferation and migration as well as the VEGF-induced proliferation and migration. Finally, inhibition of iPLA(2)-VIA reduced the VEGF-induced iPLA(2)-VIA-activity, -protein level, and -promoter activity.
  
  
  CONCLUSIONS
  A significant interaction between VEGF and iPLA(2)-VIA in the regulation of RPE cells appears to be relevant in elucidating the exact mechanisms of action in the proliferative and migratory phenotype of RPE cells in AMD.
authors.affiliation: Department of Neuroscience and Pharmacology, The Panum Institute, University of Copenhagen, Copenhagen, Denmark. akkehler@yahoo.com
authors.forename: Anne Katrine
authors.initials: AK
authors.lastname: Kehler
authors.forename: Cammilla
authors.initials: C
authors.lastname: Andersen
authors.forename: Jens Rovelt
authors.initials: JR
authors.lastname: Andreasen
authors.forename: Rupali
authors.initials: R
authors.lastname: Vohra
authors.forename: Nanna
authors.initials: N
authors.lastname: Junker
authors.forename: Kristian Arild
authors.initials: KA
authors.lastname: Poulsen
authors.forename: Miriam
authors.initials: M
authors.lastname: Kolko
mesh_terms: D015153:Blotting, Western; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D004261:DNA Replication; D054522:Group VI Phospholipases A2 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006801:Humans; D009281:Naphthalenes / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011753:Pyrones / Q000494:pharmacology; D055213:Retinal Pigment Epithelium / Q000166:cytology* / Q000201:enzymology; D015533:Transcriptional Activation; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology*
chemical_list: D009281:Naphthalenes; D010726:Phosphodiesterase Inhibitors; D011753:Pyrones; D042461:Vascular Endothelial Growth Factor A; C068314:6-(bromomethylene)tetrahydro-3-(1-naphthaleneyl)-2H-pyran-2-one; D054522:Group VI Phospholipases A2