title: Fc Receptor Inhibition Reduces Susceptibility to Oxidative Stress in Human RPE Cells Treated with Bevacizumab, but not Aflibercept.
abstract: OBJECTIVE
  VEGF-A is induced by oxidative stress, and functions as a survival factor for various cell types, including retinal pigment epithelial (RPE) cells. Anti-vascular endothelial growth factor (VEGF) drugs like aflibercept and bevacizumab have shown to be most effective in treating neovascular age-related macular degeneration (AMD), however uptake of the drugs might lead to interference with cell physiology. Herein, we evaluated the significance of the Fc receptor (FcR) within this context and moreover explored the impact of VEGF inhibition under normal conditions as well as under oxidative stress, in terms of potential adverse effects.
  
  
  METHODS
  ARPE-19 (human RPE) cells were treated with aflibercept and bevacizumab in presence or absence of H2O2 as oxidative stress stimulus. After 24h cells were evaluated for drug uptake, VEGF-A expression and secretion, levels of intracellular reactive oxygen species (ROS) as well as cell proliferation. Experiments were repeated with cells being pre-incubated with an FcR inhibitor prior to drug application.
  
  
  RESULTS
  Both drugs inhibited extracellular levels of VEGF-A and were taken up into the RPE, resulting in significantly reduced intracellular levels of VEGF-A. When oxidative stress was applied, intracellular ROS levels in cells treated with both drugs rose, and cell proliferation was reduced. Prior incubation with the FcR inhibitor lessened the uptake of bevacizumab, but not aflibercept into RPE cells, and simultaneously enhanced cell survival under oxidative stress conditions.
  
  
  CONCLUSIONS
  Our results indicate that uptake and accumulation of aflibercept and bevacizumab within RPE cells affect the intracellular VEGF-A metabolism negatively, leading to a biologically relevant reduced cell survival under oxidative stress. The FcR plays a substantial role in the uptake of bevacizumab, but not aflibercept, which allows an enhanced RPE cell survival through FcR blockage in an environment dominated by oxidative stress, as clinically significant for various inflammatory retinal disorders.
authors.affiliation: Department of Ophthalmology, University of Lx00FC;beck, Lx00FC;beck, Germany.
authors.forename: Mahdy
authors.initials: M
authors.lastname: Ranjbar
authors.forename: Max Philipp
authors.initials: MP
authors.lastname: Brinkmann
authors.forename: Dorinja
authors.initials: D
authors.lastname: Zapf
authors.forename: Yoko
authors.initials: Y
authors.lastname: Miura
authors.forename: Martin
authors.initials: M
authors.lastname: Rudolf
authors.forename: Salvatore
authors.initials: S
authors.lastname: Grisanti
mesh_terms: D020533:Angiogenesis Inhibitors / Q000009:adverse effects / Q000494:pharmacology*; D000068258:Bevacizumab / Q000009:adverse effects / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D011961:Receptors, Fc / Q000037:antagonists & inhibitors* / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor / Q000009:adverse effects / Q000494:pharmacology*; D011993:Recombinant Fusion Proteins / Q000009:adverse effects / Q000494:pharmacology*; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D020533:Angiogenesis Inhibitors; D017382:Reactive Oxygen Species; D011961:Receptors, Fc; D011993:Recombinant Fusion Proteins; D042461:Vascular Endothelial Growth Factor A; C533178:aflibercept; D000068258:Bevacizumab; D006861:Hydrogen Peroxide; D040262:Receptors, Vascular Endothelial Growth Factor