Diagenode

Emerging Role of One-Carbon Metabolism and DNA Methylation Enrichment on δ-Containing GABAA Receptor Expression in the Cerebellum of Subjects with Alcohol Use Disorders (AUD


Gatta E. et al.

Background

Cerebellum is an area of the brain particularly sensitive to the effects of acute and chronic alcohol consumption. Alcohol exposure decreases cerebellar Purkinje cell output by increasing GABA release from Golgi cells onto extrasynaptic α6/δ-containing GABAA receptors located on glutamatergic granule cells. Here, we studied whether chronic alcohol consumption induces changes in GABAA receptor subunit expression and whether these changes are associated with alterations in epigenetic mechanisms via DNA methylation.

Methods

We used a cohort of postmortem cerebellum from control and chronic alcoholics, here defined as alcohol use disorders subjects (n=25/group). S-adenosyl-methionine/S-adenosyl-homocysteine were measured by high-performance liquid chromatography. mRNA levels of various genes were assessed by reverse transcriptase-quantitative polymerase chain reaction. Promoter methylation enrichment was assessed using methylated DNA immunoprecipitation and hydroxy-methylated DNA immunoprecipitation assays.

Results

mRNAs encoding key enzymes of 1-carbon metabolism that determine the S-adenosyl-methionine/S-adenosyl-homocysteine ratio were increased, indicating higher “methylation index” in alcohol use disorder subjects. We found that increased methylation of the promoter of the δ subunit GABAA receptor was associated with reduced mRNA and protein levels in the cerebellum of alcohol use disorder subjects. No changes were observed in α1- or α6-containing GABAA receptor subunits. The expression of DNA-methyltransferases (1, 3A, and 3B) was unaltered, whereas the mRNA level of TET1, which participates in the DNA demethylation pathway, was decreased. Hence, increased methylation of the δ subunit GABAA receptor promoter may result from alcohol-induced reduction of DNA demethylation.

Conclusion

Together, these results support the hypothesis that aberrant DNA methylation pathways may be involved in cerebellar pathophysiology of alcoholism. Furthermore, this work provides novel evidence for a central role of DNA methylation mechanisms in the alcohol-induced neuroadaptive changes of human cerebellar GABAA receptor function.

Tags
MagMeDIP kit

Share this article

Published
August, 2017

Source

Products used in this publication

  • Methylation kit icon
    C02010031
    hMeDIP kit x16 (monoclonal mouse antibody)
  • MagMeDIP qPCR Kit box
    C02010021
    MagMeDIP qPCR Kit
  • default alt
    C17011041-50
    Human TSH2B promoter primer pair
  • default alt
    C17011047-50
    Human ChIP-seq grade GAPDH TSS primer pair

       Site map   |   Contact us   |   Conditions of sales   |   Conditions of purchase   |   Privacy policy   |   Diagenode Diagnostics