|Epigenetics News: June 2016|
In The News
Bivalent Regions of Cytosine Methylation and H3K27 Acetylation Suggest an Active Role for DNA Methylation at Enhancers.
In the current issue of Molecular Cell, researchers from the P. Jones lab investigate the role of DNA methylation in enhancer regions. By comparing the epigenomes of the HCT116 and DKO1 cell lines, they were able to identify that a portion of regular and super- or stretch enhancers show active H3K27ac marks co-existing with extensive DNA methylation. Additionally, DNA methylation appears to play an unexpected dual role at enhancer regions, being anti-correlated focally at transcription factor-binding sites but positively correlated globally with the active H3K27ac mark to ensure structural enhancer integrity.
Methylome-wide Analysis of Chronic HIV Infection Reveals Five-Year Increase in Biological Age and Epigenetic Targeting of HLA.
In this recent publication, researchers investigate and quantify the impact of chronic HIV infection on aging. Using 137 HIV+ individuals under sustained therapy along with 44 matched HIV− individuals, a global analysis of the whole-blood DNA methylomes was conducted. Using epigenetic models that were created and validated, it was found that chronic and recent HIV infection lead to an average aging advancement of 4.9 years and increased expected mortality risk by 19%. Additionally, decreased HLA methylation was found to be predictive of lower CD4 / CD8 T cell ratio, linking molecular aging, epigenetic regulation, and disease progression.
Pooled ChIP-Seq Links Variation in Transcription Factor Binding to Complex Disease Risk.
In this recent Cell publication, researchers in the Hunter Fraser lab introduce a pooling-based approach to mapping quantitative trait loci (QTLs) for molecular-level traits. Applying this method to five transcription factors (TFs) and a histone modification, they were able to map thousands of cis-acting QTLs, with over 25-fold lower cost compared to standard QTL mapping.