title: Balancing the activation state of the endothelium via two distinct TGF-beta type I receptors.
abstract: The generation of mice lacking specific components of the transforming growth factor-beta (TGF-beta) signal tranduction pathway shows that TGF-beta is a key player in the development and physiology of the cardiovascular system. Both pro- and anti-angiogenic properties have been ascribed to TGF-beta, for which the molecular mechanisms are unclear. Here we report that TGF-beta can activate two distinct type I receptor/Smad signalling pathways with opposite effects. TGF-beta induces phosphorylation of Smad1/5 and Smad2 in endothelial cells and these effects can be blocked upon selective inhibition of ALK1 or ALK5 expression, respectively. Whereas the TGF-beta/ALK5 pathway leads to inhibition of cell migration and proliferation, the TGF-beta/ALK1 pathway induces endothelial cell migration and proliferation. We identified genes that are induced specifically by TGF-beta-mediated ALK1 or ALK5 activation. Id1 was found to mediate the TGF-beta/ALK1-induced (and Smad-dependent) migration, while induction of plasminogen activator inhibitor-1 by activated ALK5 may contribute to the TGF-beta-induced maturation of blood vessels. Our results suggest that TGF-beta regulates the activation state of the endothelium via a fine balance between ALK5 and ALK1 signalling.
authors.affiliation: Division of Cellular Biochemistry, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands. mgoumans@nki.nl
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: Goumans
authors.forename: Gudrun
authors.initials: G
authors.lastname: Valdimarsdottir
authors.forename: Susumu
authors.initials: S
authors.lastname: Itoh
authors.forename: Alexander
authors.initials: A
authors.lastname: Rosendahl
authors.forename: Paschalis
authors.initials: P
authors.lastname: Sideras
authors.forename: Peter
authors.initials: P
authors.lastname: ten Dijke
mesh_terms: D030201:Activin Receptors, Type I / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D019556:COS Cells; D002417:Cattle; D002455:Cell Division; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D018257:Helix-Loop-Helix Motifs; D051798:Inhibitor of Differentiation Protein 1; D007700:Kinetics; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins; D015398:Signal Transduction; D051899:Smad2 Protein; D051902:Smad5 Protein; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000378:metabolism* / Q000494:pharmacology; D053773:Transforming Growth Factor beta1; D053782:Transforming Growth Factor beta3
chemical_list: D004268:DNA-Binding Proteins; D051798:Inhibitor of Differentiation Protein 1; D010750:Phosphoproteins; D017395:Plasminogen Activator Inhibitor 1; D018125:Receptors, Transforming Growth Factor beta; D012097:Repressor Proteins; D051899:Smad2 Protein; D051902:Smad5 Protein; D015534:Trans-Activators; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D053782:Transforming Growth Factor beta3; D017346:Protein Serine-Threonine Kinases; D030201:Activin Receptors, Type I; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625842:Tgfbr1 protein, mouse