title: Virally activated Ras cooperates with integrin to induce tubulogenesis in sinusoidal endothelial cell lines.
abstract: Four cell lines, named nonparenchymal 11 (NP11), NP26, NP31, and NP32, were established from sinusoidal endothelial cells (SECs) of rat liver. They still retained expression of receptors for vascular endothelial growth factor (VEGF), Fit-1, and kinase domain-containing receptor (KDR). NP31 and NP32 turned out to be incapable of tubulogenesis in basement membrane matrix (Matrigel), which belongs to endothelial properties, as shown by SECs in primary culture. Expression of temperature-sensitive, virally activated Ras (ts-v-Ras) restored tubulogenic behaviors back to NP31 only at permissive temperature. Matrigel induced long-lasting tyrosine phosphorylation of Shc, with recruitment of Grb-2 and microtubule-associated protein kinase (MAPK) activation in both parental NP31 and NP31 transformed by ts-v-Ras, which was blocked by anti-beta1 integrin antibody. Tubulogenesis was inhibited by adenovirus-mediated expression of dominant-negative Ras in human umbilical vein endothelial cells (HUVECs). PD 098059, a selective inhibitor of MAPK kinase (MEK), nearly perfectly blocked tubulogenesis by ts-v-Ras-expressing NP31 cells at permissive temperature. Furthermore, the botulinum C3 toxin, an inhibitor for Rho, caused fragmentation of branching cords in networks formed by NP31 that expressed ts-v-Ras at permissive temperature. These data suggest that the integrin-mediated Ras signals may be necessary but are not sufficient for tubulogenesis and that an artificial expression of v-Ras might substitute for the second signal required in this system.
authors.affiliation: Department of Genetics, Institute of Medical Science, University of Tokyo, Japan. ymaru@hgc.ims.u-tokyo.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Maru
authors.forename: S
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: H
authors.initials: H
authors.lastname: Ueno
authors.forename: M
authors.initials: M
authors.lastname: Shibuya
mesh_terms: D036002:ADP Ribose Transferases / Q000494:pharmacology; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D001905:Botulinum Toxins; D015820:Cadherins / Q000032:analysis; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000032:analysis; D015815:Cell Adhesion Molecules / Q000032:analysis; D002461:Cell Line, Transformed / Q000737:chemistry / Q000187:drug effects / Q000502:physiology; D003094:Collagen / Q000494:pharmacology; D003598:Cytoskeletal Proteins / Q000032:analysis; D051180:Desmoplakins; D004338:Drug Combinations; D004727:Endothelium / Q000737:chemistry / Q000166:cytology / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005109:Extracellular Matrix / Q000737:chemistry / Q000201:enzymology; D005419:Flavonoids / Q000494:pharmacology; D015967:Gene Expression Regulation, Viral; D006801:Humans; D016023:Integrins / Q000502:physiology*; D007797:Laminin / Q000494:pharmacology; D008099:Liver / Q000098:blood supply / Q000166:cytology* / Q000502:physiology; D018919:Neovascularization, Physiologic / Q000502:physiology; D011506:Proteins / Q000502:physiology; D011509:Proteoglycans / Q000494:pharmacology; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D017978:Receptors, Growth Factor / Q000235:genetics; D011975:Receptors, Mitogen / Q000235:genetics; D040262:Receptors, Vascular Endothelial Growth Factor; D012190:Retroviridae / Q000235:genetics; D055765:Shc Signaling Adaptor Proteins; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D015534:Trans-Activators; D014471:Umbilical Veins / Q000166:cytology; D051178:alpha Catenin; D051176:beta Catenin; D018631:ras Proteins / Q000235:genetics*; D018909:src Homology Domains / Q000502:physiology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; C495273:CTNNA1 protein, human; C495270:CTNNB1 protein, human; D015820:Cadherins; D015815:Cell Adhesion Molecules; C495268:Ctnnb1 protein, rat; D003598:Cytoskeletal Proteins; D051180:Desmoplakins; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D005419:Flavonoids; D016023:Integrins; D007797:Laminin; D011506:Proteins; D011509:Proteoglycans; D017978:Receptors, Growth Factor; D011975:Receptors, Mitogen; C528024:SHC1 protein, human; D055765:Shc Signaling Adaptor Proteins; C528035:Shc1 protein, rat; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin; C059485:matrigel; D003094:Collagen; D036002:ADP Ribose Transferases; C063007:exoenzyme C3, Clostridium botulinum; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D001905:Botulinum Toxins; D018631:ras Proteins; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one