title: Inhibition of tubular morphogenesis in human microvascular endothelial cells by co-culture with chondrocytes and involvement of transforming growth factor beta: a model for avascularity in human cartilage.
abstract: Tube formation in collagen gel was induced in human omental microvascular endothelial (HOME) cells in the presence of epidermal growth factor (EGF) or transforming growth factor-alpha (TGF-alpha). TGF-alpha enhanced the expression of the tissue type plasminogen activator (t-PA) gene, whereas TGF-beta increased the expression of the PA inhibitor-1 (PAI-1) gene and inhibited that of the t-PA gene. TGF-beta inhibited the tube formation of HOME cells in type I collagen gel that was enhanced in response to TGF-alpha. We have recently established an angiogenesis model in vitro in which vascular endothelial cells on type I collagen gel in an inner chamber are co-cultured with other types of cells in an outer chamber. Here we examined whether the EGF/TGF-alpha-induced tube formation in HOME cells was modulated by human chondrocytes co-culture in the outer chamber. TGF-alpha-dependent tube formation of HOME cells was inhibited when human chondrocytes were co-cultured in the outer chamber. This chondrocyte-induced inhibition of tube formation was partly abrogated by co-administration of anti-TGF-beta antibody. These findings suggest that TGF-beta is partly involved in the human chondrocyte-dependent inhibition of tube formation by human microvascular endothelial cells. This is the first model system demonstrating that avascularity of human chondrocytes is partly due to TGF-beta family produced from them.
authors.affiliation: Department of Orthopedics, Oita Medical University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tada
authors.forename: T
authors.initials: T
authors.lastname: Fukunaga
authors.forename: Y
authors.initials: Y
authors.lastname: Wakabayashi
authors.forename: S
authors.initials: S
authors.lastname: Masumi
authors.forename: Y
authors.initials: Y
authors.lastname: Sato
authors.forename: H
authors.initials: H
authors.lastname: Izumi
authors.forename: K
authors.initials: K
authors.lastname: Kohno
authors.forename: M
authors.initials: M
authors.lastname: Kuwano
mesh_terms: D002356:Cartilage / Q000098:blood supply* / Q000166:cytology / Q000648:ultrastructure; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology*; D006801:Humans; D008870:Microtubules / Q000502:physiology; D008954:Models, Biological; D016212:Transforming Growth Factor beta / Q000737:chemistry*
chemical_list: D016212:Transforming Growth Factor beta