title: Effects of semaphorin 3A on retinal pigment epithelial cell activity.
abstract: OBJECTIVE
  Semaphorin 3A (Sema3A), a chemorepellant guidance protein, has been shown to be crucial for neural and vascular remodeling. This study is designed to examine the effects of Sema3A on RPE cell activity both in vitro and in vivo.
  
  
  METHODS
  Retinal pigment epithelial were incubated with Sema3A, or VEGF- and Sema3A-containing medium. Cell proliferation, migration, cell cycle, apoptosis, cocultured human umbilical vein endothelial cells tube formation, VEGF receptor 2 (VEGFR2) and neuropilin 1 (Nrp1) receptor expression, VEGF- and pigment epithelium-derived factor (PEDF) concentration, and c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinases (p38MAPK) signaling pathway studies were measured. A rabbit proliferative vitreoretinopathy (PVR) model was used for in vivo study. Subconfluent ARPE19 cells were injected intravitreously with or without Sema3A. Data were analyzed with Graphpad Prism 5.0 software.
  
  
  RESULTS
  In vitro, Sema3A not only induced RPE cell cycle arrest and inhibited RPE migration under normal culture conditions, but also inhibited exogenous and endogenous VEGF165-induced cell activities. These activities included proliferation, migration, cell cycle arrest, JNK and p38MAPK signaling pathway phosphorylation, and cocultured endothelial cell tube formation. It is shown that both VEGF165 and Sema3A induced the upregulation of VEGFR2 and Nrp1 receptors. Activity inhibition was mediated by impeding VEGF165 utilization and possibly mediated by competitive inhibition of VEGF165 binding to its receptor VEGFR2, but not by the suppression of VEGF165 secretion. In vivo, Sema3A inhibited PVR, which is induced by RPE proliferation.
  
  
  CONCLUSIONS
  These results suggested that Sema3A could be a useful therapeutic strategy for preventing RPE malfunction.
authors.affiliation: Key Laboratory of Vision Loss and Restoration, Ministry of Education, Department of Ophthalmology, Peking University People's Hospital, Beijing, China.
authors.forename: Yujing
authors.initials: Y
authors.lastname: Bai
authors.forename: Wenzhen
authors.initials: W
authors.lastname: Yu
authors.forename: Na
authors.initials: N
authors.lastname: Han
authors.forename: Fei
authors.initials: F
authors.lastname: Yang
authors.forename: Yaoyao
authors.initials: Y
authors.lastname: Sun
authors.forename: Lijuan
authors.initials: L
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
authors.forename: Lvzhen
authors.initials: L
authors.lastname: Huang
authors.forename: Aiyi
authors.initials: A
authors.lastname: Zhou
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Xiaoxin
authors.initials: X
authors.lastname: Li
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D018920:Coculture Techniques; D004195:Disease Models, Animal; D005136:Eye Proteins / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000502:physiology; D009414:Nerve Growth Factors / Q000378:metabolism; D020011:Protective Agents / Q000494:pharmacology*; D011817:Rabbits; D040262:Receptors, Vascular Endothelial Growth Factor / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D040121:Semaphorin-3A / Q000494:pharmacology*; D015843:Serpins / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D042442:Vascular Endothelial Growth Factors / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000502:physiology; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D015415:Biomarkers; D005136:Eye Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D009414:Nerve Growth Factors; D020011:Protective Agents; D040262:Receptors, Vascular Endothelial Growth Factor; D040121:Semaphorin-3A; D015843:Serpins; D042442:Vascular Endothelial Growth Factors; D048051:p38 Mitogen-Activated Protein Kinases; D000099174:Pigment Epithelium-Derived Factor
keywords: retinal pigment epithelial (RPE); semaphorin 3A; vascular endothelial growth factor (VEGF)