Functional DNA methylation in a transcript specific 3'UTR region of TrkB associates with suicide.

TitleFunctional DNA methylation in a transcript specific 3'UTR region of TrkB associates with suicide.
Publication TypeJournal Article
Year of Publication2014
AuthorsMaussion G, Yang J, Suderman M, Diallo A, Nagy C, Arnovitz M, Mechawar N, Turecki G
Date Published2014 Aug

Previous studies indicate that a subgroup of suicide completers has low cortical brain expression levels of TrkB-T1, a TrkB gene transcript that is highly expressed in astrocytes. Epigenetic modifications, including methylation changes in the TrkB promoter, partially explain TrkB-T1 low expression levels in brain tissue from suicide completers. The aim of this study was to investigate whether methylation changes in other regions of the TrkB gene could also contribute to the significant downregulation of the TrkB-T1 transcript observed in the brain of suicide completers. Methylation levels were assessed on BA8/9 from suicide completers expressing low TrkB-T1 transcript levels and controls, using custom-made Agilent arrays tiling the whole TrkB gene. After statistical correction for multiple testing, five probes located in the TrkB-T1 3'UTR region were found hypermethylated in the frontal cortex of suicide completers. These results were validated for four CpGs spanning a 150 bp sequence by cloning and Sanger sequencing bisulfite treated DNA. We found a significant correlation between the methylation level at these four CpGs and TrkB-T1 expression in BA8/9. Site-specific hypermethylation on this 3'UTR sequence induced decreased luciferase activity in reporter gene cell assays. Site-specific differential methylation in the TrkB-T1 3'UTR region associates with functional changes in TrkB-T1 expression and may play a significant role in the important decrease of cortical TrkB-T1 expression observed among suicide completers.

Alternate JournalEpigenetics
PubMed ID24802768
PubMed Central IDPMC4164491
Grant List8914 / / PHS HHS / United States