title: Editor's Highlight: Identification and Characterization of Teratogenic Chemicals Using Embryonic Stem Cells Isolated From a Wnt/β-Catenin-Reporter Transgenic Mouse Line.
abstract: Embryonic stem cells (ESCs) are commonly used for the analysis of gene function in embryonic development and provide valuable models for human diseases. In recent years, ESCs have also become an attractive tool for toxicological testing, in particular for the identification of teratogenic compounds. We have recently described a Bmp-reporter ESC line as a new tool to identify teratogenic compounds and to characterize the molecular mechanisms mediating embryonic toxicity. Here we describe the use of a Wnt/β-Catenin-reporter ESC line isolated from a previously described mouse line that carries the LacZ reporter gene under the control of a β-Catenin responsive promoter. The reporter ESC line stably differentiates into cardiomyocytes within 12 days. The reporter was endogenously induced between day 3-5 of differentiation reminiscent of its expression in vivo, in which strong LacZ activity is detected around gastrulation. Subsequently its expression becomes restricted to mesodermal cells and cells undergoing an epithelial to mesenchymal transition. The Wnt/β-Catenin-dependent expression of the reporter protein allowed quantification of dose- and time-dependent effects of teratogenic chemicals. In particular, valproic acid reduced reporter activity on day 7 whereas retinoic acid induced reporter activity on day 5 at concentrations comparable to the ones inhibiting the formation of functional cardiomyocytes, the classical read-out of the embryonic stem cell test (EST). In addition, we were also able to show distinct effects of teratogenic chemicals on the Wnt/β-Catenin-reporter compared with the previously described Bmp-reporter ESCs. Thus, different reporter cell lines provide complementary tools for the identification and analysis of potentially teratogenic compounds.
authors.affiliation: *Department of Chemical & Product Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany Josephine.Kugler@bfr.bund.de.
authors.forename: Josephine
authors.initials: J
authors.lastname: Kugler
authors.affiliation: Emeritus Laboratory, Max-Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Kemler
authors.affiliation: *Department of Chemical & Product Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Luch
authors.affiliation: Department of Experimental Toxicology and ZEBET, German Federal Institute for Risk Assessment (BfR), Berlin, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Oelgeschläger
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D053595:Embryonic Stem Cells / Q000187:drug effects*; D017930:Genes, Reporter; D051379:Mice; D008822:Mice, Transgenic; D032383:Myocytes, Cardiac / Q000166:cytology; D060888:Real-Time Polymerase Chain Reaction; D013723:Teratogens / Q000633:toxicity*; D014212:Tretinoin / Q000633:toxicity; D014635:Valproic Acid / Q000633:toxicity; D051153:Wnt Proteins / Q000235:genetics*; D051176:beta Catenin / Q000235:genetics*
chemical_list: D013723:Teratogens; D051153:Wnt Proteins; D051176:beta Catenin; D014212:Tretinoin; D014635:Valproic Acid
keywords: Wnt; differentiation; embryo; stem cells; LacZ; reporter gene