title: TGFbeta1 induces vasculogenesis and inhibits angiogenic sprouting in an embryonic stem cell differentiation model: respective contribution of ALK1 and ALK5.
abstract: Transforming growth factor-beta1 (TGFbeta1) is a multipotent cytokine that is involved in the regulation of vasculogenesis and angiogenesis. However, the actions of TGFbeta1 on vascular cells in vitro and in vivo are extremely complex and still incompletely understood. The aim of the present study was to investigate the role of TGFbeta1 and its two type I receptors, activin receptor-like kinase-1 (ALK1) and ALK5, in an embryonic stem cell (ESC) differentiation model that recapitulates the developmental steps of vasculogenesis and sprouting angiogenesis. We show that TGFbeta1 increases endothelial cell differentiation in a vascular endothelial growth factor (VEGF)-independent manner and inhibits endothelial tube formation. Furthermore, we demonstrate that undifferentiated ESCs express ALK5 but do not express ALK1, with ALK1 being expressed only after day 5 of differentiation. Finally, we demonstrate that constitutively active forms of ALK1 and ALK5 both inhibit growth factor-induced endothelial sprouting from embryoid bodies. In conclusion, the use of this ESC differentiation model allowed us to propose the following model: at early stages of development, TGFbeta1, through the ALK5 receptor, is provasculogenic in a VEGF-independent manner. Later, in differentiated endothelial cells in which both ALK1 and ALK5 are expressed, both receptors are implicated in inhibition of sprouting angiogenesis.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale (INSERM) EMI 01-05, Département Réponse et Dynamique Cellulaires (DRDC), Commissariat à l'Energie Atomique (CEA)-Grenoble, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Mallet
authors.forename: Daniel
authors.initials: D
authors.lastname: Vittet
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Feige
authors.forename: Sabine
authors.initials: S
authors.lastname: Bailly
mesh_terms: D030201:Activin Receptors, Type I / Q000235:genetics / Q000378:metabolism*; D030301:Activin Receptors, Type II; D000818:Animals; D001808:Blood Vessels / Q000187:drug effects / Q000196:embryology / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000187:drug effects / Q000378:metabolism*; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D007150:Immunohistochemistry; D007700:Kinetics; D051379:Mice; D018919:Neovascularization, Physiologic / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases; D012333:RNA, Messenger / Q000378:metabolism; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053773:Transforming Growth Factor beta1 / Q000378:metabolism* / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D042461:Vascular Endothelial Growth Factor A; D017346:Protein Serine-Threonine Kinases; D030201:Activin Receptors, Type I; D030301:Activin Receptors, Type II; C498931:Acvrl1 protein, mouse; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625842:Tgfbr1 protein, mouse