title: Pigment epithelium-derived factor inhibits fibroblast-growth-factor-2-induced capillary morphogenesis of endothelial cells through Fyn.
abstract: Pigment epithelium-derived factor (PEDF) exerts anti-angiogenic actions. However, the signal-transduction pathways regulated by PEDF remain to be elucidated. We show here that PEDF inhibited fibroblast growth factor 2 (FGF-2) induced capillary morphogenesis of a murine brain capillary endothelial cell line (IBE cells) and of human umbilical-vein endothelial cells (HUVECs) cultured on growth-factor-reduced Matrigel. We previously showed that FGF-2-mediated capillary morphogenesis was blocked by the Src-kinase inhibitor PP2 and that expression of dominant negative Fyn in IBE cells inhibited capillary morphogenesis. We examined the effect of PEDF on kinase activity of Fyn and found that PEDF downregulated FGF-2-promoted Fyn activity by tyrosine phosphorylation at the C-terminus in a Fes-dependent manner. In a stable IBE cell line expressing kinase-inactive Fes (KE5-15 Fes cells), PEDF failed to inhibit FGF-2-induced capillary morphogenesis or Fyn activity. PEDF induced the colocalization of Fyn and Fes in IBE cells expressing wild-type Fes, but not in KE5-15 Fes cells. In addition, wild-type Fes increased the tyrosine phosphorylation of Fyn in vitro, suggesting that Fes might directly phosphorylate Fyn. Expression of constitutively active Fyn (Y531F) in IBE cells exhibited capillary morphogenesis in the absence of FGF-2 and was resistant for PEDF treatment. Our results suggest that PEDF downregulates Fyn through Fes, resulting in inhibition of FGF-2-induced capillary morphogenesis of endothelial cells.
authors.affiliation: Department of Molecular Microbiology and Immunology, Division of Endothelial Cell Biology, Nagasaki University Graduate School of Biomedical Science, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. shigeruk@net.nagasaki-u.ac.jp
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kanda
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Mochizuki
authors.forename: Takao
authors.initials: T
authors.lastname: Nakamura
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Miyata
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Matsuyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kanetake
mesh_terms: D000818:Animals; D001921:Brain / Q000098:blood supply / Q000378:metabolism; D002196:Capillaries / Q000378:metabolism / Q000473:pathology*; D002478:Cells, Cultured; D003094:Collagen / Q000494:pharmacology; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins; D015536:Down-Regulation; D004338:Drug Combinations; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D005136:Eye Proteins / Q000502:physiology*; D016222:Fibroblast Growth Factor 2 / Q000737:chemistry / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D020690:GTPase-Activating Proteins; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D007797:Laminin / Q000494:pharmacology; D051379:Mice; D009389:Neovascularization, Pathologic; D018919:Neovascularization, Physiologic; D009414:Nerve Growth Factors / Q000502:physiology*; D009687:Nuclear Proteins / Q000737:chemistry; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D011509:Proteoglycans / Q000494:pharmacology; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051076:Proto-Oncogene Proteins c-fyn; D011743:Pyrimidines / Q000494:pharmacology; D011994:Recombinant Proteins / Q000737:chemistry; D012097:Repressor Proteins; D015843:Serpins / Q000502:physiology*; D015398:Signal Transduction; D014162:Transfection; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism; D014471:Umbilical Veins / Q000166:cytology; D019061:src-Family Kinases / Q000378:metabolism*; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D003094:Collagen; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D004338:Drug Combinations; D005136:Eye Proteins; D016222:Fibroblast Growth Factor 2; D020690:GTPase-Activating Proteins; D020662:Guanine Nucleotide Exchange Factors; D007797:Laminin; D009414:Nerve Growth Factors; D009687:Nuclear Proteins; D011509:Proteoglycans; D011518:Proto-Oncogene Proteins; D051076:Proto-Oncogene Proteins c-fyn; D011743:Pyrimidines; D011994:Recombinant Proteins; D012097:Repressor Proteins; D015843:Serpins; D014443:Tyrosine; D019061:src-Family Kinases; D000099174:Pigment Epithelium-Derived Factor; C412373:AG 1879; C074560:ARHGAP35 protein, human; C513041:Arhgap35 protein, mouse; C059485:matrigel; C494957:FYN protein, human; C494960:Fyn protein, mouse