title: Association of valproate-induced teratogenesis with histone deacetylase inhibition in vivo.
abstract: Chemically induced birth defects are an important public health and human problem. Here we use Xenopus and zebrafish as models to investigate the mechanism of action of a well-known teratogen, valproic acid (VPA). VPA is a drug used in treatment of epilepsy and bipolar disorder but causes spina bifida if taken during pregnancy. VPA has several biochemical activities, including inhibition of histone deacetylases (HDACs). To investigate the mechanism of action of VPA, we compared its effects in Xenopus and zebrafish embryos with those of known HDAC inhibitors and noninhibitory VPA analogs. We found that VPA and other HDAC inhibitors cause very similar and characteristic developmental defects whereas VPA analogs with poor inhibitory activity in vivo have little teratogenic effect. Unbiased microarray analysis revealed that the effects of VPA and trichostatin A (TSA), a structurally unrelated HDAC inhibitor, are strikingly concordant. The concordance is apparent both by en masse correlation of fold-changes and by detailed similarity of dose-response profiles of individual genes. Together, the results demonstrate that the teratogenic effects of VPA are very likely mediated specifically by inhibition of HDACs.
authors.affiliation: Department of Cancer Biology, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Nadia
authors.initials: N
authors.lastname: Gurvich
authors.forename: Melissa G
authors.initials: MG
authors.lastname: Berman
authors.forename: Ben S
authors.initials: BS
authors.lastname: Wittner
authors.forename: Robert C
authors.initials: RC
authors.lastname: Gentleman
authors.forename: Peter S
authors.initials: PS
authors.lastname: Klein
authors.forename: Jeremy B A
authors.initials: JB
authors.lastname: Green
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000209:etiology*; D000818:Animals; D000927:Anticonvulsants / Q000633:toxicity*; D004791:Enzyme Inhibitors / Q000633:toxicity*; D005260:Female; D020869:Gene Expression Profiling; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids / Q000633:toxicity*; D013045:Species Specificity; D016135:Spinal Dysraphism / Q000139:chemically induced; D014158:Transcription, Genetic / Q000187:drug effects; D014635:Valproic Acid / Q000633:toxicity*; D014981:Xenopus; D015027:Zebrafish / Q000196:embryology
chemical_list: D000927:Anticonvulsants; D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; C012589:trichostatin A; D014635:Valproic Acid