title: Expression of PDGFRα is a determinant of the PVR potential of ARPE19 cells.
abstract: OBJECTIVE
  Previous studies indicate that the expression of platelet-derived growth factor (PDGF) receptor α (PDGFRα) dramatically increases the ability of fibroblasts to induce experimental proliferative vitreoretinopathy (PVR). The purpose of this study was to determine whether PDGFRα contributed to the PVR potential of retinal pigment epithelial (RPE) cells, one of the most abundant cell types in PVR membranes.
  
  
  METHODS
  PDGFRα expression in human ARPE19 cells was increased or decreased by stably expressing the PDGFRα cDNA or short hairpin (sh) RNA directed at PDGFRα, respectively. The level of PDGFRα expression in the resulting panel of cell lines was either barely detectable (KD), standard (similar to the level of primary RPE cells), or overexpressed approximately 80-fold. Western blot analysis was used to assess the level of p53 and the activation state of PDGFRα and Akt. The following cellular responses were monitored: proliferation, apoptosis, and contraction. The PVR potential of cells was tested in a rabbit model of PVR in which cells were coinjected with platelet-rich plasma into the vitreous.
  
  
  RESULTS
  Comparison of KD and overexpressing cells indicated that high-level expression of PDGFRα dramatically augmented signaling events, cellular responses, and the PVR potential of ARPE19 cells. However, all these outcomes were also significantly increased, albeit not as robustly, by PDGFRα expression to the level typically present in RPE cells.
  
  
  CONCLUSIONS
  Even though RPE cells express substantially less PDGFRα than fibroblasts, it significantly boosts PVR-related signaling events, cellular responses, and the PVR potential of ARPE19 cells. These studies suggest that inhibiting activation, signaling, or both by PDGFRα has the potential to prevent the development of PVR.
authors.affiliation: The Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts 02114, USA.
authors.forename: Hetian
authors.initials: H
authors.lastname: Lei
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Rhéaume
authors.forename: Gisela
authors.initials: G
authors.lastname: Velez
authors.forename: Shizuo
authors.initials: S
authors.lastname: Mukai
authors.forename: Andrius
authors.initials: A
authors.lastname: Kazlauskas
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D004195:Disease Models, Animal; D015870:Gene Expression / Q000502:physiology; D006801:Humans; D053657:Platelet-Rich Plasma; D011817:Rabbits; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics* / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D018630:Vitreoretinopathy, Proliferative / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D014822:Vitreous Body / Q000378:metabolism / Q000473:pathology
chemical_list: D020796:Receptor, Platelet-Derived Growth Factor alpha