PUBLICATION

Methylmercury interferes with glucocorticoid receptor: Potential role in the mediation of developmental neurotoxicity

Authors
Spulber, S., Raciti, M., Dulko-Smith, B., Lupu, D., Rüegg, J., Nam, K., Ceccatelli, S.
ID
ZDB-PUB-180303-13
Date
2018
Source
Toxicology and applied pharmacology   354: 94-100 (Journal)
Registered Authors
Keywords
Alternative methods, Developmental neurotoxicity, Endocrine disruptor, Glucocorticoid receptor, Methylmercury
MeSH Terms
  • Humans
  • Molecular Dynamics Simulation
  • Binding Sites
  • Receptors, Glucocorticoid/chemistry
  • Receptors, Glucocorticoid/drug effects*
  • Receptors, Glucocorticoid/genetics
  • Receptors, Glucocorticoid/metabolism
  • Signal Transduction/drug effects
  • Gene Expression Regulation, Developmental/drug effects
  • Risk Assessment
  • Nervous System/drug effects*
  • Nervous System/embryology
  • Nervous System/metabolism
  • Embryonic Development/drug effects
  • Animals
  • Mercury Poisoning, Nervous System/embryology
  • Mercury Poisoning, Nervous System/etiology*
  • Mercury Poisoning, Nervous System/genetics
  • Mercury Poisoning, Nervous System/metabolism
  • Toxicity Tests
  • HeLa Cells
  • Toxicology/methods
  • Animals, Genetically Modified
  • Protein Binding
  • Zebrafish
  • Ligands
  • Methylmercury Compounds/chemistry
  • Methylmercury Compounds/metabolism
  • Methylmercury Compounds/toxicity*
PubMed
29499248 Full text @ Tox. App. Pharmacol.
CTD
29499248
Abstract
Methylmercury (MeHg) is a widespread environmental contaminant with established developmental neurotoxic effects. Computational models have identified glucocorticoid receptor (GR) signaling to be a key mediator behind the birth defects induced by Hg, but the mechanisms were not elucidated. Using molecular dynamics simulations, we found that MeHg can bind to the GR protein at Cys736 (located close to the ligand binding site) and distort the conformation of the ligand binging site. To assess the functional consequences of MeHg interaction with GR, we used a human cell line expressing a luciferase reporter system (HeLa AZ-GR). We found that 100 nM MeHg does not have any significant effect on GR activity alone, but the transactivation of gene expression by GR upon Dex (a synthetic GR agonist) administration was reduced in cells pre-treated with MeHg. Similar effects were found in transgenic zebrafish larvae expressing a GR reporter system (SR4G). Next we asked whether the effects of developmental exposure to MeHg are mediated by the effects on GR. Using a mutant zebrafish line carrying a loss-of-function mutation in the GR (grS357) we could show that the effects of developmental exposure to 2.5 nM MeHg are mitigated in absence of functional GR signaling. Taken together, our data indicate that inhibition of GR signaling may have a role in the developmental neurotoxic effects of MeHg.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping