PUBLICATION

Early-Life Benzo[a]Pyrene Exposure Causes Neurodegenerative Syndromes in Adult Zebrafish (Danio rerio) and the Mechanism Involved

Authors
Gao, D., Wang, C., Xi, Z., Zhou, Y., Wang, Y., Zuo, Z.
ID
ZDB-PUB-170323-2
Date
2017
Source
Toxicological sciences : an official journal of the Society of Toxicology   157(1): 74-84 (Journal)
Registered Authors
Keywords
DNA methylation., benzo[a]pyrene, early-life stages, neurodegenerative disease, zebrafish
MeSH Terms
  • Amyloid beta-Peptides/metabolism
  • Animals
  • Apoptosis/drug effects
  • Benzo(a)pyrene/toxicity*
  • Brain/cytology
  • Brain/drug effects
  • DNA (Cytosine-5-)-Methyltransferase 1/metabolism
  • DNA Methylation
  • Dose-Response Relationship, Drug
  • Environmental Exposure
  • Female
  • Locomotion/drug effects
  • Neurodegenerative Diseases/chemically induced*
  • Neurons/drug effects
  • Neurons/metabolism
  • Neurotransmitter Agents/metabolism
  • Peptide Fragments/metabolism
  • Pregnancy
  • Prenatal Exposure Delayed Effects*
  • RNA, Messenger/metabolism
  • Zebrafish/embryology*
PubMed
28329817 Full text @ Toxicol. Sci.
CTD
28329817
Abstract
There is increasing recognition of the importance of early-life environmental exposures in health disorders at later-life stages. The aim of this study was to evaluate whether early-life exposure to benzo[a]pyrene (BaP) could induce neurodegenerative syndromes at later-life stages in zebrafish. Embryos were exposed to BaP at doses of 0, 0.05, 0.5, 5, and 50 nM from early embryogenesis to 96 h post-fertilization (hpf), then transferred to clean water and maintained for 365 days. We found that BaP decreased locomotor and cognitive ability, neurotransmitter levels of dopamine, 3,4-dihydroxyphenylacetic acid and norepinephrine; and induced loss of dopaminergic neurons and resulted in neurodegeneration. Additionally, BaP increased amyloid β protein and cell apoptosis in the adult zebrafish brain. Further, DNA methyltransferase 1 (DNMT1) and DNMT3a were up-regulated in 96 hpf larvae and the adult brain. MeDIP-sequencing data of the 96 hpf larvae identified 235 differentially methylated genes in promoter, with the fold change > 1.5. Guanylate cyclase 2F (gucy2f) and dopamine receptor D4 related sequence (drd4-rs) were hypermethylation promoters, whereas zinc finger C4H2 domain (zc4h2) was a hypomethylation promoter in 96 hpf larvae and the adult brain. The mRNA levels of gucy2f and drd4-rs were down-regulated, and zc4h2 was up-regulated. Our findings suggested that the lasting modifications of DNA methylation were associated with neurodegenerative syndromes in adult zebrafish as a result of early-life BaP exposure.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping