Short-Time Gene Expression Response to Valproic Acid and Valproic Acid analogs in Mouse Embryonic Stem Cells
2011 (English)In: Toxicological Sciences, ISSN 1096-6080, E-ISSN 1096-0929, Vol. 121, no 2, 328-342 p.Article in journal (Refereed) Published
The prediction of potential developmental toxicity in vitro could be based ontoxicogenomic endpoints a short time after exposure in cultured embryo-derived celllines. Our previous microarray studies in P19 mouse embryonal carcinoma cells andmouse embryos have indicated that the teratogen valproic acid (VPA), an inducerof neural tube defects, deregulates the expression of a large number of genes, manyof which have critical roles in neural tube formation and closure. In this study weexposed undifferentiated R1 mouse embryonic stem (ES) cells to VPA and VPA analogto define genes whose expression responses may be related to teratogenic potential.After 6 h of exposure, RNA samples were subjected to microarray analysis usingCodeLinkTM Mouse Whole Genome Bioarrays. VPA (1 mM) and the teratogenic VPAanalog (S)-2-pentyl-4-pentynoic (0.25 mM or 0.5 mM) deregulate a large numberof genes, whereas for the non-teratogenic (and potentially pharmacologically active)analog 2-ethyl-4-methyl-pentanoic acid (1 mM) the expression of only a few geneswas affected. Biological process ontology groups related to embryonic development,morphogenesis, and cell behavior were overrepresented among the affected teratogentarget genes. Multivariate analysis indicated that as few as five genes (out of ~2500array probes correlating with the separation) could separate the data set accordingto teratogenicity. Genes deregulated by the two teratogens showed a substantialoverlap with genes previously found to be deregulated by VPA in P19 cells and mouseembryos. A panel of candidate genes was defined as potential markers predictiveof teratogenicity and evaluated through TaqMan low density array analysis. Theteratogens butyrate and trichostatin A, which like VPA and (S)-2-pentyl-4-pentynoicacid are known histone deacetylase (HDAC) inhibitors, induced similar responsesas these two teratogens for a large subset of markers. This indicates that HDACinhibition may be a major mechanism by which VPA induces gene deregulation andpossibly teratogenicity. Other teratogenic compounds tested had no effect on thepanel of selected markers, indicating that they may not be predicitive of teratogenicityfor compounds acting through other mechanisms than VPA.
Place, publisher, year, edition, pages
2011. Vol. 121, no 2, 328-342 p.
developmental/teratology, embryonic stem cells, in vitro and alternatives to animal testing, microarray, predictive toxicology, toxicogenomics
Pharmacology and Toxicology
Research subject Toxicology
IdentifiersURN: urn:nbn:se:uu:diva-110247DOI: 10.1093/toxsci/kfr070ISI: 000290931000011PubMedID: 21427059OAI: oai:DiVA.org:uu-110247DiVA: diva2:275578