PUBLICATION

Histone Methyltransferase G9a Plays an Essential Role on Nicotine Preference in Zebrafish

Authors
Faillace, M.P., Ortiz, J., Rocco, L., Bernabeu, R.
ID
ZDB-PUB-240131-1
Date
2024
Source
Molecular neurobiology   61(9): 6245-6263 (Journal)
Registered Authors
Keywords
BIX-01294, Conditioned place preference, Epigenetic regulation, G9a/GLP complex, Histone lysine methylation, Nicotine, nAchR α-subunits
MeSH Terms
  • Animals
  • Azepines/pharmacology
  • Histone-Lysine N-Methyltransferase*/metabolism
  • Histones/metabolism
  • Male
  • Nicotine*/pharmacology
  • Quinazolines/pharmacology
  • Receptors, Nicotinic/metabolism
  • Reward
  • Zebrafish*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
PubMed
38289455 Full text @ Mol. Neurobiol.
Abstract
Psychostimulants regulate behavioral responses in zebrafish via epigenetic mechanisms. We have previously shown that DNA methylation and histone deacetylase (HDAC) inhibition abolish nicotine-induced conditioned place preference (CPP) but little is known about the role of histone methylation in addictive-like behaviors. To assess the influence of histone methylation on nicotine-CPP, zebrafish were treated with a histone (H3) lysine-9 (K9) dimethyltransferase G9a/GLP inhibitor, BIX-01294 (BIX), which was administered before conditioning sessions. We observed a dual effect of the inhibitor BIX: at high doses inhibited while at low doses potentiated nicotine reward. Transcriptional expression of α6 and α7 subunits of the nicotinic acetylcholine receptor and of G9a, DNA methyl transferase-3, and HDAC-1 was upregulated in zebrafish with positive scores for nicotine-CPP. Changes in relative levels of these mRNA molecules reflected the effects of BIX on nicotine reward. BIX treatment per sé did not affect transcriptional levels of epigenetic enzymes that regulate trimethylation or demethylation of H3. BIX reduced H3K9me2 protein levels in a dose-dependent manner in key structures of the reward pathway. Thus, our findings indicated that different doses of BIX differentially affect nicotine CPP via strong or weak inhibition of G9a/GLP activity. Additionally, we found that the lysine demethylase inhibitor daminozide abolished nicotine-CPP and drug seeking. Our data demonstrate that H3 methylation catalyzed by G9a/GLP is involved in nicotine-CPP induction. Dimethylation of K9 at H3 is an important epigenetic modification that should be considered as a potential therapeutic target to treat nicotine reward and perhaps other drug addictions.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping