title: Expression and potential role of angiopoietins and Tie-2 in early development of the mouse metanephros.
abstract: Angiopoietins (Ang) are secreted factors which bind the Tie-2 receptor and modulate endothelial growth. This signalling system is known to be expressed in later stages of maturation of the mouse metanephros, the adult kidney precursor. In this study, by using reverse transcription polymerase chain reaction and Northern and Western blotting, we demonstrated that Ang-1, Ang-2, and Tie-2 were expressed during early metanephrogenesis when interstitial and glomerular capillaries begin to form. By using immunohistochemistry, embryonic kidney capillaries in the interstitium and glomeruli expressed Tie-2 at a later stage of differentiation compared with vascular endothelial growth factor receptor-2 and platelet-endothelial cell adhesion molecule. Addition of 200 ng/ml Ang-1 to explanted embryonic day (E) 12.5 metanephroi increased the proportion of vascular glomeruli that formed during 1 week in culture. These results are consistent with the hypotheses that Tie-2 has a role in vascular growth in the early stages of mammalian nephrogenesis and that Tie-2 activation may maintain the integrity of recently formed interstitial and glomerular vessels.
authors.affiliation: Nephro-Urology Unit, Institute of Child Health, London, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Kolatsi-Joannou
authors.forename: X Z
authors.initials: XZ
authors.lastname: Li
authors.forename: T
authors.initials: T
authors.lastname: Suda
authors.forename: H T
authors.initials: HT
authors.lastname: Yuan
authors.forename: A S
authors.initials: AS
authors.lastname: Woolf
mesh_terms: D042683:Angiopoietin-1; D042702:Angiopoietin-2; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002454:Cell Differentiation; D007150:Immunohistochemistry; D007668:Kidney / Q000196:embryology; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000502:physiology*; D009924:Organ Culture Techniques; D014176:Protein Biosynthesis; D011506:Proteins / Q000502:physiology*; D011518:Proto-Oncogene Proteins; D042787:Receptor, TIE-2; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013997:Time Factors
chemical_list: D042683:Angiopoietin-1; D042702:Angiopoietin-2; C467628:Angpt1 protein, mouse; C105373:MEN1 protein, human; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D042787:Receptor, TIE-2