PUBLICATION

Ligand-specific transcriptional mechanisms underlie aryl hydrocarbon receptor-mediated developmental toxicity of oxygenated PAHs

Authors
Goodale, B.C., La Du, J., Tilton, S.C., Sullivan, C.M., Bisson, W.H., Waters, K.M., Tanguay, R.L.
ID
ZDB-PUB-150705-3
Date
2015
Source
Toxicological sciences : an official journal of the Society of Toxicology   147(2): 397-411 (Journal)
Registered Authors
La Du, Jane K., Tanguay, Robyn L., Tilton, Susan C.
Keywords
12-dione, Benzanthrone, OPAH, RNA-seq, aryl hydrocarbon receptor, benz(a)anthracene-7, zebrafish
Datasets
GEO:GSE68666
MeSH Terms
  • Animals
  • Benz(a)Anthracenes/metabolism
  • Benz(a)Anthracenes/toxicity*
  • Fluorescent Antibody Technique
  • Gene Expression Profiling
  • Ligands
  • Polycyclic Aromatic Hydrocarbons/metabolism
  • Polycyclic Aromatic Hydrocarbons/toxicity*
  • Receptors, Aryl Hydrocarbon/drug effects
  • Receptors, Aryl Hydrocarbon/metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription, Genetic/drug effects
  • Zebrafish
PubMed
26141390 Full text @ Toxicol. Sci.
CTD
26141390
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are priority environmental contaminants that exhibit mutagenic, carcinogenic, proinflammatory and teratogenic properties. Oxygen-substituted PAHs (OPAHs) are formed during combustion processes and via phototoxidation and biological degradation of parent (unsubstituted) PAHs. Despite their prevalence both in contaminated industrial sites and in urban air, OPAH mechanisms of action in biological systems are relatively understudied. Like parent PAHs, OPAHs exert structure-dependent mutagenic activities and activation of the aryl hydrocarbon receptor (AHR) and cytochrome p450 metabolic pathway (CYP1A). Four-ring OPAHs 1,9-benz-10-anthrone (BEZO) and benz(a)anthracene-7,12-dione (7,12-B[a]AQ) cause morphological aberrations and induce markers of oxidative stress in developing zebrafish with similar potency, but only 7,12-B[a]AQ induces robust Cyp1a protein expression. We investigated the role of the AHR in mediating the toxicity of BEZO and 7,12-B[a]AQ, and found that knockdown of AHR2 rescued developmental effects caused by both compounds. Using RNA-seq and molecular docking, we identified transcriptional responses that precede developmental toxicity induced via differential interaction with AHR2. Redox-homeostasis genes were affected similarly by these two OPAHs, while 7,12-B[a]AQ preferentially activated phase 1 metabolism and BEZO uniquely decreased visual system genes. Analysis of biological functions and upstream regulators suggests that BEZO is a weak AHR agonist, but interacts with other transcriptional regulators to cause developmental toxicity in an AHR-dependent manner. Identifying ligand-dependent AHR interactions and signaling pathways is essential for understanding toxicity of this class of environmentally relevant compounds.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping