The transcriptional response to oxidative stress during vertebrate development: effects of tert-butylhydroquinone and 2,3,7,8-tetrachlorodibenzo-p-dioxin

• Published in: PloS one Vol. 9; no. 11; p. e113158
• Main Authors: Hahn, Mark E, McArthur, Andrew G, Karchner, Sibel I, Franks, Diana G, Jenny, Matthew J, Timme-Laragy, Alicia R, Stegeman, John J, Woodin, Bruce R, Cipriano, Michael J, Linney, Elwood
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 17-11-2014; Public Library of Science (PLoS)
• Subjects: Analysis; Animal behavior; Animal diseases; Animals; Animals, Genetically Modified - genetics; Animals, Genetically Modified - growth & development; Antioxidants - toxicity; Binding sites; Bioinformatics; Biology and life sciences; Cellular signal transduction; CYP1A protein; Cytochrome P450; Danio rerio; Deoxyribonucleic acid; Development and progression; Developmental stages; Dioxins; DNA; DNA damage; DNA microarrays; DNA probes; Ecology and Environmental Sciences; Embryo, Nonmammalian - drug effects; Embryo, Nonmammalian - metabolism; Embryo, Nonmammalian - pathology; Embryonic development; Embryos; Fertilization; Fluorescence; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Developmental - drug effects; Genes; Genetic aspects; Genetic engineering; Genetic research; Genomes; Genomics; Glutathione; Glutathione transferase; Green fluorescent protein; Health sciences; Heat shock proteins; Herbicides; Hsp70 protein; Hydroquinones - toxicity; Laboratories; Larvae; Medicine and Health Sciences; Molecular biology; Neurodegenerative diseases; Neurological diseases; Oxidants; Oxidation-Reduction; Oxidative stress; Oxidative Stress - drug effects; Oxidizing agents; Physical Sciences; Pigmentation; Polychlorinated Dibenzodioxins - toxicity; Polymerase chain reaction; Research and Analysis Methods; Rodents; Superoxide dismutase; t-Butylhydroquinone; TCDD; Telomerase; Teratogenesis; Teratogens - toxicity; Toxicity; Transcription; Transcription (Genetics); Transcription factors; Transduction; Vertebrates; Zebrafish; Zebrafish - genetics; Zebrafish - growth & development; Zebrafish Proteins - genetics; Zebrafish Proteins - metabolism; United States > US; Massachusetts
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0113158

Oxidative stress is an important mechanism of chemical toxicity, contributing to teratogenesis and to cardiovascular and neurodegenerative diseases. Developing animals may be especially sensitive to chemicals causing oxidative stress. The developmental expression and inducibility of anti-oxidant defenses through activation of NF-E2-related factor 2 (NRF2) affect susceptibility to oxidants, but the embryonic response to oxidants is not well understood. To assess the response to chemically mediated oxidative stress and how it may vary during development, zebrafish embryos, eleutheroembryos, or larvae at 1, 2, 3, 4, 5, and 6 days post fertilization (dpf) were exposed to DMSO (0.1%), tert-butylhydroquinone (tBHQ; 10 µM) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 2 nM) for 6 hr. Transcript abundance was assessed by real-time qRT-PCR and microarray. qRT-PCR showed strong (4- to 5-fold) induction of gstp1 by tBHQ as early as 1 dpf. tBHQ also induced gclc (2 dpf), but not sod1, nqo1, or cyp1a. TCDD induced cyp1a but none of the other genes. Microarray analysis showed that 1477 probes were significantly different among the DMSO-, tBHQ-, and TCDD-treated eleutheroembryos at 4 dpf. There was substantial overlap between genes induced in developing zebrafish and a set of marker genes induced by oxidative stress in mammals. Genes induced by tBHQ in 4-dpf zebrafish included those involved in glutathione synthesis and utilization, signal transduction, and DNA damage/stress response. The strong induction of hsp70 determined by microarray was confirmed by qRT-PCR and by use of transgenic zebrafish expressing enhanced green fluorescent protein (EGFP) under control of the hsp70 promoter. Genes strongly down-regulated by tBHQ included mitfa, providing a molecular explanation for the loss of pigmentation in tBHQ-exposed embryos. These data show that zebrafish embryos are responsive to oxidative stress as early as 1 dpf, that responsiveness varies with development in a gene-specific manner, and that the oxidative stress response is substantially conserved in vertebrate animals.