AHR2 morpholino knockdown reduces the toxicity of total particulate matter to zebrafish embryos

Journal Article · Sat Oct 15 04:00:00 EDT 2016 · Toxicology and Applied Pharmacology

DOI:https://doi.org/10.1016/J.TAAP.2016.08.024· OSTI ID:22690814

Massarsky, Andrey ^[1]; Bone, Audrey J. ^[1]; Dong, Wu ^[1]; Hinton, David E. ^[1]; Prasad, G. L. ^[2]; Di Giulio, Richard T. ^[1]

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1. Nicholas School of the Environment, Duke University, Durham, NC 27708 (United States)
2. RAI Services Company, Winston-Salem, NC 27101 (United States)

The zebrafish embryo has been proposed as a ‘bridge model’ to study the effects of cigarette smoke on early development. Previous studies showed that exposure to total particulate matter (TPM) led to adverse effects in developing zebrafish, and suggested that the antioxidant and aryl hydrocarbon receptor (AHR) pathways play important roles. This study investigated the roles of these two pathways in mediating TPM toxicity. The study consisted of four experiments. In experiment I, zebrafish embryos were exposed from 6 h post fertilization (hpf) until 96 hpf to TPM{sub 0.5} and TPM{sub 1.0} (corresponding to 0.5 and 1.0 μg/mL equi-nicotine units) in the presence or absence of an antioxidant (N-acetyl cysteine/NAC) or a pro-oxidant (buthionine sulfoximine/BSO). In experiment II, TPM exposures were performed in embryos that were microinjected with nuclear factor erythroid 2-related factor 2 (Nrf2), AHR2, cytochrome P450 1A (CYP1A), or CYP1B1 morpholinos, and deformities were assessed. In experiment III, embryos were exposed to TPM, and embryos/larvae were collected at 24, 48, 72, and 96 hpf to assess several genes associated with the antioxidant and AHR pathways. Lastly, experiment IV assessed the activity and protein levels of CYP1A and CYP1B1 after exposure to TPM. We demonstrate that the incidence of TPM-induced deformities was generally not affected by NAC/BSO treatments or Nrf2 knockdown. In contrast, AHR2 knockdown reduced, while CYP1A or CYP1B1 knockdowns elevated the incidence of some deformities. Moreover, as shown by gene expression the AHR pathway, but not the antioxidant pathway, was induced in response to TPM exposure, providing further evidence for its importance in mediating TPM toxicity. - Highlights: • Total particulate matter (TPM) is the particulate phase of cigarette smoke. • Zebrafish is proposed as a ‘bridge model’ to study the effects of TPM. • We investigate the roles of antioxidant and aryl hydrocarbon receptor (AHR) pathways. • We demonstrate that the AHR pathway mediates TPM toxicity.

• OSTI ID: 22690814
• Journal Information: Toxicology and Applied Pharmacology, Journal Name: Toxicology and Applied Pharmacology Vol. 309; ISSN TXAPA9; ISSN 0041-008X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
60 APPLIED LIFE SCIENCES
ANTIOXIDANTS
AROMATICS
BIOLOGICAL STRESS
CYSTEINE
CYTOCHROMES
EMBRYOS
FERTILIZATION
GENES
LARVAE
NICOTINE
OXIDATION
OXIDIZERS
PARTICULATES
RECEPTORS
TOBACCO PRODUCTS
TOBACCO SMOKES
TOXICITY