Polycomb repressive complex 2 epigenomic signature defines age-associated hypermethylation and gene expression...

Area of Science:

• Epigenetics and Genomics
• Aging Research

Background:

• Age-associated changes in gene expression and DNA methylation are known, but unifying epigenomic principles of aging are poorly understood.
• Advances in epigenomic data from projects like ENCODE and Roadmap Epigenomics offer new opportunities to study aging mechanisms.

Purpose of the Study:

• To identify common epigenomic mechanisms altered by age-associated differentially methylated regions (aDMRs) and age-associated genes (aGENs).
• To investigate the role of the Polycomb Repressive Complex 2 (PRC2) signature in aging-related epigenetic modifications.

Main Methods:

• Analysis of epigenomic data, including DNA methylation and histone modification marks, from multiple independent aging studies.
• Identification and characterization of age-associated differentially methylated regions (aDMRs) and age-associated genes (aGENs).
• Examination of chromatin states and regulatory element signatures associated with aDMRs and aGENs.

Main Results:

• aDMRs and aGENs share a common Polycomb Repressive Complex 2 (PRC2) signature, characterized by specific histone marks (H3K27me3, H3K4me1) and binding sites (EZH2, SUZ12, CTCF).
• This PRC2 signature is associated with a 'poised promoter' chromatin state and is depleted in active regulatory marks and 'active promoter' states.
• The PRC2 signature is linked to age-associated hypermethylation and gene expression changes, and is generally stable across cell types.

Conclusions:

• The PRC2 signature represents a common epigenomic context for genomic regions undergoing age-associated hypermethylation and gene expression alterations.
• This finding provides unifying epigenomic principles underlying the aging process.
• The study highlights the conserved role of PRC2 in age-related epigenetic regulation.