title: An in vivo chemical library screen in Xenopus tadpoles reveals novel pathways involved in angiogenesis and lymphangiogenesis.
abstract: Angiogenesis and lymphangiogenesis are essential for organogenesis but also play important roles in tissue regeneration, chronic inflammation, and tumor progression. Here we applied in vivo forward chemical genetics to identify novel compounds and biologic mechanisms involved in (lymph)angiogenesis in Xenopus tadpoles. A novel 2-step screening strategy involving a simple phenotypic read-out (edema formation or larval lethality) followed by semiautomated in situ hybridization was devised and used to screen an annotated chemical library of 1280 bioactive compounds. We identified 32 active compounds interfering with blood vascular and/or lymphatic development in Xenopus. Selected compounds were also tested for activities in a variety of endothelial in vitro assays. Finally, in a proof-of-principle study, the adenosine A1 receptor antagonist 7-chloro-4-hydroxy-2-phenyl-1,8-naphthyridine, an inhibitor of blood vascular and lymphatic development in Xenopus, was shown to act also as a potent antagonist of VEGFA-induced adult neovascularization in mice. Taken together, the present chemical library screening strategy in Xenopus tadpoles represents a rapid and highly efficient approach to identify novel pathways involved in (lymph)angiogenesis. In addition, the recovered compounds represent a rich resource for in-depth analysis, and their drug-like features will facilitate further evaluation in preclinical models of inflammation and cancer metastasis.
authors.affiliation: Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland.
authors.forename: Roland E
authors.initials: RE
authors.lastname: Kälin
authors.forename: Nadja E
authors.initials: NE
authors.lastname: Bänziger-Tobler
authors.forename: Michael
authors.initials: M
authors.lastname: Detmar
authors.forename: André W
authors.initials: AW
authors.lastname: Brändli
mesh_terms: D058916:Adenosine A1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists / Q000302:isolation & purification / Q000494:pharmacology; D000818:Animals; D001685:Biological Factors / Q000302:isolation & purification* / Q000494:pharmacology / Q000502:physiology; D002478:Cells, Cultured / Q000187:drug effects; D004353:Drug Evaluation, Preclinical; D004487:Edema / Q000209:etiology; D004625:Embryo, Nonmammalian; D042783:Endothelial Cells / Q000187:drug effects; D005260:Female; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods*; D007814:Larva; D042583:Lymphangiogenesis / Q000502:physiology*; D051379:Mice; D009287:Naphthyridines / Q000302:isolation & purification / Q000494:pharmacology; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D010641:Phenotype; D054852:Small Molecule Libraries; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D014982:Xenopus laevis / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*
chemical_list: C543632:7-chloro-4-hydroxy-2-phenyl-1,8-naphthyridine; D058916:Adenosine A1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists; D001685:Biological Factors; D009287:Naphthyridines; D054852:Small Molecule Libraries; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse