Histone modification landscape and the key significance of H3K27me3 in myocardial ischaemia/reperfusion injury

Histone modifications play crucial roles in the pathogenesis of myocardial ischaemia/reperfusion(I/R)injury.However,a genome-wide map of histone modifications and the underlying epigenetic signatures in myocardial I/R injury have not been established.Here,we integrated transcriptome and epigenome of histone modifications to characterize epigenetic signatures after I/R injury.Disease-specific histone mark alterations were mainly found in H3K27me3-,H3K27ac-,and H3K4me1-marked regions 24 and 48 h after I/R.Genes differentially modified by H3K27ac,H3K4me1 and H3K27me3 were involved in immune response,heart conduction or contraction,cytoskeleton,and angiogenesis.H3K27me3 and its methyltransferase polycomb repressor complex 2(PRC2)were upregulated in myocardial tissues after I/R.Upon selective inhibition of EZH2(the catalytic core of PRC2),the mice manifest improved cardiac function,enhanced angiogenesis,and reduced fibrosis.Further investigations confirmed that EZH2 inhibition regulated H3K27me3 modification of multiple pro-angiogenic genes and ultimately enhanced angiogenic properties in vivo and in vitro.This study delineates a landscape of histone modifications in myocardial I/R injury,and identifies H3K27me3 as a key epigenetic modifier in I/R process.The inhibition of H3K27me3 and its methyltransferase might be a potential strategy for myocardial I/R injury intervention.

The silencing transcription factor REST targets UCHL1 to regulate inflammatory response and fibrosis during cardiac hypertrophy

RE1 silencing transcription factor(REST)plays a key role in embryonic development and fetal cardiac gene reactivation.1 However,understanding of the role of REST in cardiac remodeling is very limited.A recent study has shown that cardiac-specific REST knockout increases Gao expression,and impairs Ca^(2+)processing in ventricular 1 myocytes,leading to cardiac dysfunction.