Dataset Information

Structure-Dependent Developmental Toxicity of Alkyl-Substituted Naphthalenes

ABSTRACT: Naphthalene and its alkyl-substituted derivatives are among the most abundant polycyclic aromatic hydrocarbons (PAHs) in environmental and human exposure studies, yet their developmental toxicity and mode of action remain poorly understood due to challenges in testing of semi-volatile compounds. This study developed a vial based high through-put method to effectively assess the activity of naphthalenes and a set of 24 alkyl-substituted naphthalenes. Early life stage zebrafish were exposed to a concentration series of each chemical (0-50 µM) in rotating sealed glass vials to minimize volatilization. Benchmark concentration (BMC50) values were calculated for morphological endpoints and lowest effect levels were determined for behavioral effects. The data were assessed for evidence of a narcotic mode of action using body burden measurements for select chemicals and logKow modeling. Targeted transcriptomics at a single concentration and timepoint as well as in silico molecular docking were conducted to generate mode of action hypothesis. The vial method enabled detection of highly variable developmental toxicity not previously observed using standard 96-well plate exposures. LogKow and body burden were poor predictors of toxicity, suggesting a non-narcotic mode of action. Transcriptomic analysis revealed a limited but notable set of differentially expressed genes, with evidence for the disruption of glucocorticoid signaling pathways. Molecular docking identified potential protein targets (e.g., CYP1A2, NT5E, FOLR1) that may mediate observed effects. This study demonstrates the importance of appropriate exposure methods for semi-volatile compounds, reveals structure-dependent toxicity among alkyl-substituted naphthalenes, and provides a foundation for further mechanistic studies and improved risk assessment of alkyl-substituted PAHs.

ORGANISM(S): Danio rerio

PROVIDER: GSE296410 | GEO | 2025/05/23

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment as components of fossil fuels and by-products of combustion. These multi-ring chemicals differentially activate the Aryl Hydrocarbon Receptor (AHR) in a structurally-dependent manner, and induce toxicity via both AHR-dependent and -independent mechanisms. PAH exposure is known to induce developmental malformations in zebrafish embryos, and recent studies have shown cardiac toxicity induced by compounds with low AHR affinity. Unraveling the potentially diverse molecular mechanisms of PAH toxicity is essential for understanding the hazard posed by complex PAH mixtures present in the environment. We analyzed transcriptional responses to PAH exposure in zebrafish embryos exposed to benz(a)anthracene (BAA), dibenzothiophene (DBT) and pyrene (PYR) at a concentration that induces developmental malformations by 120 hours post-fertilization (hpf). Whole genome microarray analysis of mRNA expression at 24 and 48 hpf identified genes that were differentially regulated over time and in response to the three PAH structures. PAH body burden was analyzed at these time points using GC-MS, and demonstrated differences in PAH uptake into the embryos. This was important for discerning dose-related differences from those that represented unique molecular mechanisms. While BAA misregulated the smallest number of transcripts, it caused strong induction of cyp1a and other genes known to be downstream of the AHR, which were not induced by the other two PAHs. Analysis of functional roles of misregulated genes and their predicted regulatory transcription factors also distinguished the BAA response from regulatory networks disrupted by DBT and PYR exposure. These results indicate that systems approaches can be used to classify the toxicity of PAHs based on the networks perturbed following exposure and may provide a path for unraveling the toxicity of complex PAH mixtures. Gene expression was measured in zebrafish embryos after exposure to PAHs. Embryos were batch-exposed in groups of 40 to 25 μM BAA, 25 μM DBT, 25 μM PYR or 1% DMSO vehicle control starting at 6 hpf and collected at 24 or 48 hpf. Four independent biological replicates were prepared for each treatment. The reference was a pool of zebrafish embryos exposed to DMSO control until 24 and 48 hpf.

Dataset Information

Structure-Dependent Developmental Toxicity of Alkyl-Substituted Naphthalenes

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets