title: The role of PGE2 receptor EP4 in pathologic ocular angiogenesis.
abstract: OBJECTIVE
  PGE(2) binds to PGE(2) receptors (EP(1-4)). The purpose of the present study was to investigate the role of the EP(4) receptor in angiogenic cell behaviors of retinal Müller cells and retinal microvascular endothelial cells (RMECs) and to assess the efficacy of an EP(4) antagonist in rat models of oxygen-induced retinopathy (OIR) and laser-induced choroidal neovascularization (LCNV).
  
  
  METHODS
  Müller cells derived from COX-2-null mice were treated with increasing concentrations of the EP(4) agonist PGE(1)-OH, and wild-type Müller cells were treated with increasing concentrations of the EP(4) antagonist L-161982; VEGF production was assessed. Human RMECs (HRMECs) were treated with increasing concentrations of L-161982, and cell proliferation and tube formation were assessed. Rats subjected to OIR or LCNV were administered L-161982, and the neovascular area was measured.
  
  
  RESULTS
  COX-2-null mouse Müller cells treated with increasing concentrations of PGE(1)-OH demonstrated a significant increase in VEGF production (P < or = 0.0165). Wild-type mouse Müller cells treated with increasing concentrations of L-161982 demonstrated a significant decrease in VEGF production (P < or = 0.0291). HRMECs treated with increasing concentrations of L-161982 demonstrated a significant reduction in VEGF-induced cell proliferation (P < or = 0.0033) and tube formation (P < 0.0344). L-161982 treatment significantly reduced pathologic neovascularization in OIR (P < 0.0069) and LCNV (P < or = 0.0329).
  
  
  CONCLUSIONS
  Preliminary investigation has demonstrated that EP(4) activation or inhibition influences the behaviors of two retinal cell types known to play roles in pathologic ocular angiogenesis. These findings suggest that the EP(4) receptor may be a valuable therapeutic target in neovascular eye disease.
authors.affiliation: Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Yanni
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Barnett
authors.forename: Monika L
authors.initials: ML
authors.lastname: Clark
authors.forename: John S
authors.initials: JS
authors.lastname: Penn
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D049109:Cell Proliferation / Q000187:drug effects; D002829:Choroid / Q000098:blood supply; D020256:Choroidal Neovascularization / Q000209:etiology / Q000378:metabolism* / Q000517:prevention & control; D051546:Cyclooxygenase 2 / Q000235:genetics; D015232:Dinoprostone / Q000378:metabolism; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D017075:Laser Coagulation / Q000009:adverse effects; D008297:Male; D051379:Mice; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism*; D010100:Oxygen / Q000633:toxicity; D051381:Rats; D011914:Rats, Inbred BN; D017207:Rats, Sprague-Dawley; D018078:Receptors, Prostaglandin E / Q000819:agonists / Q000037:antagonists & inhibitors / Q000502:physiology*; D058309:Receptors, Prostaglandin E, EP4 Subtype; D015861:Retinal Neovascularization / Q000139:chemically induced / Q000378:metabolism* / Q000517:prevention & control; D012171:Retinal Vessels / Q000187:drug effects; D013876:Thiophenes / Q000494:pharmacology; D014230:Triazoles / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: C508711:L-161982; C545650:PTGER4 protein, human; C545651:Ptger4 protein, mouse; C545652:Ptger4 protein, rat; D018078:Receptors, Prostaglandin E; D058309:Receptors, Prostaglandin E, EP4 Subtype; D013876:Thiophenes; D014230:Triazoles; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; D015232:Dinoprostone; D010100:Oxygen