Methylation of the SLC6a2 gene promoter in major depression and panic disorder

PLoS One. 2013 Dec 2;8(12):e83223. doi: 10.1371/journal.pone.0083223. eCollection 2013.

Abstract

Reduced function of the noradrenaline transporter (NET) has been demonstrated in patients with major depressive disorder (MDD) and panic disorder. Attempts to explain NET dysfunction in MDD and panic disorder by genetic variation in the NET gene SLC6a2 have been inconclusive. Transcriptional silencing of the SLC6a2 gene may be an alternative mechanism which can lead to NET dysfunction independent of DNA sequence. The objective of this study was to characterise the DNA methylation state of the SLC6a2 gene promoter in patients with MDD and panic disorder. SLC6a2 promoter methylation was also analysed before and after antidepressant treatment. This study was performed with DNA from blood, using bisulphite sequencing and EpiTYPER methylation analyses. Patients with MDD or panic disorder were not found to differ significantly from healthy controls in the pattern of methylation of the SLC6a2 gene promotor. While significant correlations between methylation levels at some CpG sites and physiological measures were identified, overall the variation in DNA methylation between patients was small, and the significance of this variation remains equivocal. No significant changes in SLC6a2 promoter methylation were observed in response to antidepressant treatment. Further in-depth analysis of alternative mechanisms of transcriptional regulation of the SLC6a2 gene in human health and disease would be of value.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • DNA Methylation / genetics*
  • Depressive Disorder, Major / genetics*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Norepinephrine Plasma Membrane Transport Proteins / genetics*
  • Panic Disorder / genetics*
  • Promoter Regions, Genetic / genetics*

Substances

  • Norepinephrine Plasma Membrane Transport Proteins
  • SLC6A2 protein, human

Grants and funding

This work was supported by grants from the NHMRC. The Baker IDI Heart & Diabetes Institute is supported in part by the Victorian Government's OIS Program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.