title: Platelets, thrombospondin-1 and human dermal fibroblasts cooperate for stimulation of endothelial cell tubulogenesis through VEGF and PAI-1 regulation.
abstract: During cutaneous wound repair, platelets, dermal fibroblasts (DF) and endothelial cells all cooperate. We have presently investigated the regulation of endothelial cell tubulogenesis by human platelet thrombospondin-1 (TSP-1), in comparison to transforming growth factor-beta1 (TGF-beta1) and total platelet lysates (PL), in a fibrin matrix cell culture system incorporating DF. TSP-1, TGF-beta1 and PL all stimulated VEGF expression in DF dose dependently at mRNA and protein level. TSP-1- and PL-treated DF supernatants significantly stimulated capillary-like structure formation (tubulogenesis) by dermal microvascular endothelial cells (HMEC-1 and HDMEC), in part via VEGF, as confirmed with neutralizing anti-VEGF antibodies. In contrast, TGF-beta1-treated DF supernatants did not induce tubulogenesis. This apparent discrepancy could be explained by the differential expression regulation in HMEC-1 of fibrinolysis and metalloproteinase mediators by TSP-1 and TGF-beta1. TSP-1 potently reduced the expression of plasminogen activator inhibitor-1 (PAI-1) (mRNA and protein), whereas TGF-beta1 enhanced it. The crucial role of PAI-1 in tubulogenesis was confirmed via the addition of active recombinant PAI-1, which abrogated tubulogenesis. In contrast, neutralizing PAI-1 antibodies enhanced tubulogenesis. Our results suggest that platelet TSP-1 released in a wound stimulates endothelial cell tubulogenesis through an upregulation of DF VEGF expression and a downregulation of endothelial cell PAI-1 expression.
authors.affiliation: INSERM, U553, Univ Paris 7, IUH, Paris, F-75010, France.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Kellouche
authors.forename: Samia
authors.initials: S
authors.lastname: Mourah
authors.forename: Arnaud
authors.initials: A
authors.lastname: Bonnefoy
authors.forename: Damien
authors.initials: D
authors.lastname: Schoëvaert
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Podgorniak
authors.forename: Fabien
authors.initials: F
authors.lastname: Calvo
authors.forename: Marc F
authors.initials: MF
authors.lastname: Hoylaerts
authors.forename: Chantal
authors.initials: C
authors.lastname: Legrand
authors.forename: Christine
authors.initials: C
authors.lastname: Dosquet
mesh_terms: D001792:Blood Platelets / Q000502:physiology*; D002478:Cells, Cultured; D020405:Dermis / Q000098:blood supply* / Q000166:cytology / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000378:metabolism*; D005337:Fibrin / Q000494:pharmacology; D005347:Fibroblasts / Q000502:physiology; D005786:Gene Expression Regulation; D006801:Humans; D008954:Models, Biological; D018919:Neovascularization, Physiologic / Q000187:drug effects; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism*; D019700:Thrombospondin 1 / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D019699:Thrombospondins / Q000378:metabolism; D046509:Tissue Culture Techniques; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology; D014404:Tubulin / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D000099262:Thrombospondin 2
chemical_list: D005337:Fibrin; D017395:Plasminogen Activator Inhibitor 1; D019700:Thrombospondin 1; D019699:Thrombospondins; D053773:Transforming Growth Factor beta1; D014404:Tubulin; D042461:Vascular Endothelial Growth Factor A; D000099262:Thrombospondin 2