Epigenetics: an Expanding New Piece of the Stroke Puzzle

Genome-wide association studies of stroke have revealed a polygenomic pathology in which contributions from individual genes are highly variable. This variability appears to be due at least in part to contributions from epigenetic mechanisms that fall into three main categories. The first includes mechanisms that mediate DNA methylation and attenuate gene expression. The second category includes the enzymes that add and remove acetyl groups to lysine residues in histone proteins and thereby facilitate or inhibit their dissociation for DNA with subsequent increases or decreases in gene expression, respectively. The third category includes the pathways that regulate the synthesis and action of micro-RNAs that regulate mRNA translation. Together, these epigenetic mechanisms convert environmental conditions and physiological stresses into long-term changes in gene expression and translation. Studies of epigenetic mechanisms in stoke are in their infancy but offer great promise for better understanding of stroke pathology and the potential viability of new strategies for its treatment.