title: Identification of a soluble form of the angiopoietin receptor TIE-2 released from endothelial cells and present in human blood.
abstract: The transmembrane tyrosine kinase TIE-2, the receptor for the angiopoietins-1 and -2, has been shown to be involved in angiogenic processes. Investigating the regulation of TIE-2 expression on endothelial cells, we found that stimulators such as PMA induce a decrease of TIE-2 protein from the cell surface without affecting TIE-2 mRNA. In conditioned media of PMA stimulated endothelial cells, a soluble form of this receptor comprising parts of the extracellular domain can be detected. Using a sandwich ELISA, we were able to detect and quantify TIE-2 receptors in cell lysates (representing the whole transmembrane receptor) and in cell culture supernatants (representing a soluble form of this receptor, sTIE-2). Several factors influencing the shedding process e.g. basic FGF could be identified. Finally, the soluble form of TIE-2 could also be detected in human biological fluids such as sera and plasma from healthy controls.
authors.affiliation: Institute of Molecular Oncology, Tumor Biology Center, Freiburg, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Reusch
authors.forename: B
authors.initials: B
authors.lastname: Barleon
authors.forename: K
authors.initials: K
authors.lastname: Weindel
authors.forename: G
authors.initials: G
authors.lastname: Martiny-Baron
authors.forename: A
authors.initials: A
authors.lastname: Gödde
authors.forename: G
authors.initials: G
authors.lastname: Siemeister
authors.forename: D
authors.initials: D
authors.lastname: Marmé
mesh_terms: D000818:Animals; D001483:Base Sequence; D017077:Culture Media, Conditioned; D017931:DNA Primers; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D009363:Neoplasm Proteins / Q000097:blood / Q000378:metabolism*; D011233:Precipitin Tests; D011518:Proto-Oncogene Proteins; D042787:Receptor, TIE-2; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D017077:Culture Media, Conditioned; D017931:DNA Primers; C105373:MEN1 protein, human; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D042787:Receptor, TIE-2; D013755:Tetradecanoylphorbol Acetate