title: VEGF164(165) as the pathological isoform: differential leukocyte and endothelial responses through VEGFR1 and VEGFR2.
abstract: OBJECTIVE
  Vascular endothelial growth factor (VEGF) induces angiogenesis and vascular permeability and is thought to be operative in several ocular vascular diseases. The VEGF isoforms are highly conserved among species; however, little is known about their differential biological functions in adult tissue. In the current study, the inflammatory potential of two prevalent VEGF isoform splice variants, VEGF(120(121)) and VEGF(164(165)), was studied in the transparent and avascular adult mouse cornea.
  
  
  METHODS
  Controlled-release pellets containing equimolar amounts of VEGF(120) and VEGF(164) were implanted in corneas. The mechanisms underlying this differential response of VEGF isoforms were explored. The response of VEGF in cultured endothelial cells was determined by Western blot analysis. The response of VEGF isoforms in leukocytes was also investigated.
  
  
  RESULTS
  VEGF(164) was found to be significantly more potent at inducing inflammation. In vivo blockade of VEGF receptor (VEGFR)-1 significantly suppressed VEGF(164)-induced corneal inflammation. In vitro, VEGF(165) more potently stimulated intracellular adhesion molecule (ICAM)-1 expression on endothelial cells, an effect that was mediated by VEGFR2. VEGF(164) was also more potent at inducing the chemotaxis of monocytes, an effect that was mediated by VEGFR1. In an immortalized human leukocyte cell line, VEGF(165) was found to induce tyrosine phosphorylation of VEGFR1 more efficiently.
  
  
  CONCLUSIONS
  Taken together, these data identify VEGF(164(165)) as a proinflammatory isoform and identify multiple mechanisms underlying its proinflammatory biology.
authors.affiliation: Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Usui
authors.forename: Susumu
authors.initials: S
authors.lastname: Ishida
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamashiro
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kaji
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Poulaki
authors.forename: Johnny
authors.initials: J
authors.lastname: Moore
authors.forename: Tara
authors.initials: T
authors.lastname: Moore
authors.forename: Shiro
authors.initials: S
authors.lastname: Amano
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Horikawa
authors.forename: Darlene
authors.initials: D
authors.lastname: Dartt
authors.forename: Matthew
authors.initials: M
authors.lastname: Golding
authors.forename: David T
authors.initials: DT
authors.lastname: Shima
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Adamis
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018929:Cell Culture Techniques; D002634:Chemotaxis, Leukocyte / Q000187:drug effects; D003315:Cornea / Q000187:drug effects* / Q000473:pathology; D016510:Corneal Neovascularization / Q000139:chemically induced* / Q000473:pathology; D004730:Endothelium, Vascular / Q000187:drug effects*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D019169:Jurkat Cells / Q000187:drug effects; D007958:Leukocyte Count; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010766:Phosphorylation; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D018799:Intercellular Adhesion Molecule-1; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2