Cardiovascular disease remains the leading cause of mortality worldwide, necessitating deeper insights into its molecular underpinnings beyond genetic predisposition. Epigenetic modifications, particularly methylation changes affecting DNA, proteins, and RNA, have emerged as critical regulators of gene expression implicated in cardiac pathophysiology. These heritable yet reversible chemical alterations govern chromatin architecture, transcriptional activity, and post-transcriptional processing without changing underlying nucleotide sequences. Within the spectrum of cardiovascular pathology—including ischemic heart disease, cardiac hypertrophy, heart failure, and atherosclerosis—dysregulated methylation patterns contribute substantially to disease initiation, progression, and phenotypic manifestation. Understanding the distinct and convergent roles of these three major methylation modalities offers promising avenues for developing novel diagnostic biomarkers and targeted therapeutic interventions that could transform precision medicine in cardiology.
DNA methylation represents the most extensively characterized epigenetic mechanism in cardiovascular pathology, predominantly occurring at CpG dinucleotides through the action of DNA methyltransferases (DNMTs). In ischemic heart disease, bidirectional regulatory relationships exist between myocardial ischemia and DNA methylation status, where hypoxic conditions alter genomic methylation patterns while aberrant methylation exacerbates ischemic injury. Genome-wide analyses have identified numerous differentially methylated positions associated with coronary heart disease, notably involving genes regulating one-carbon metabolism, calcium handling like SERCA2a, and inflammatory responses. For instance, hypermethylation of the Sirt1 gene promoter induced by gestational diabetes increases offspring susceptibility to ischemic damage, whereas elevated methylation at specific loci such as TIMP1, ABCA1, and ACAT1 in peripheral blood correlates with coronary artery disease severity. In cardiac hypertrophy and heart failure, altered DNA methylation patterns affect genes controlling contractile function, calcium homeostasis, and fetal gene program reactivation, with global hypomethylation often accompanying pathological remodeling. Atherosclerosis similarly exhibits characteristic DNA methylation signatures, including hypomethylation of vascular smooth muscle cell genes and hypermethylation of protective genes like estrogen receptor-alpha, contributing to endothelial dysfunction and plaque formation.
Protein methylation, encompassing both histone and non-histone protein modifications, constitutes another crucial regulatory layer in cardiovascular disease pathogenesis. Histone lysine and arginine methylation dynamically modulate chromatin accessibility and gene transcription, with specific marks exhibiting distinct functional consequences. Histone H3K9 trimethylation maintains cardiomyocyte cell cycle arrest and differentiation, while its loss permits hypertrophic growth. The histone methyltransferase G9a protects against pathological cardiac hypertrophy by suppressing pro-hypertrophic gene expression, whereas EZH2-mediated H3K27 trimethylation contributes to diabetic cardiomyopathy and atherosclerosis progression through transcriptional repression of protective genes like ABCA1. Beyond histones, arginine methylation by protein arginine methyltransferases (PRMTs) significantly impacts cardiovascular pathology. PRMT4 overexpression exacerbates myocardial infarction-induced cardiac remodeling by promoting cardiomyocyte apoptosis, while PRMT5 deficiency correlates with increased acute myocardial infarction risk. These modifications interact dynamically with other epigenetic mechanisms, creating complex regulatory networks that govern cellular responses to hemodynamic stress, ischemic injury, and metabolic perturbations.
RNA N6-methyladenosine (m6A) methylation has recently emerged as a critical post-transcriptional regulator in cardiovascular biology, orchestrated by methyltransferases (METTL3, METTL14), demethylases (FTO, ALKBH5), and reader proteins (YTH domain proteins, IGF2BPs). In ischemic heart disease, METTL3 expression increases following myocardial infarction and hypoxia-reperfusion injury, promoting cardiomyocyte apoptosis through TFEB methylation and lysosomal autophagy pathway inhibition. Conversely, ALKBH5-mediated m6A demethylation stabilizes mRNAs encoding reparative factors like ErbB4 and WNT5A, facilitating post-ischemic fibroblast activation and angiogenesis. Cardiac hypertrophy exhibits enhanced m6A modification levels, with METTL3 driving compensatory hypertrophy while YTHDF2 prevents pathological remodeling by regulating Myh7 and MYZAP mRNA stability. In heart failure, reduced FTO expression correlates with elevated m6A levels and diminished SERCA2a expression, whereas WTAP deficiency impairs chromatin accessibility of cardiac transcription factors. Atherosclerosis involves m6A-mediated regulation of endothelial inflammation through METTL14-dependent stabilization of FOXO1 and Braf mRNAs in macrophages, highlighting the multifaceted roles of RNA methylation in vascular pathology.
The intricate interplay between DNA, protein, and RNA methylation forms a complex epigenetic network rather than isolated regulatory events. Histone modifications directly influence DNA methylation patterns, as H3K36me3 facilitates DNMT3 binding while H3K4 methylation inhibits enzymatic activity at promoters. RNA methylation conversely affects DNA methylation through microRNAs that target DNMTs, creating feedback loops exemplified by miR-29b regulation of DNA methylation machinery. Protein methylation and RNA methylation similarly converge, with METTL3 recruiting histone methyltransferase complexes to influence heterochromatin formation, while PRMT3-mediated arginine methylation of METTL14 modulates m6A deposition. These crosstalk mechanisms suggest that therapeutic targeting of single modification types may trigger compensatory responses through interconnected pathways, necessitating comprehensive epigenetic strategies.
Clinical translation of methylation research in cardiology has progressed substantially, with epigenome-wide association studies identifying robust DNA methylation biomarkers for coronary heart disease and myocardial infarction risk stratification. Novel CRISPR-based epigenetic editing technologies now enable durable, reversible gene silencing, as demonstrated by PCSK9-targeting approaches achieving sustained LDL-cholesterol reduction in preclinical models. Future investigations integrating multi-omics approaches, single-cell epigenomic profiling, and machine learning algorithms will likely uncover hierarchical relationships between methylation modifications and their downstream effects. Developing organoid models and patient-derived induced pluripotent stem cells for personalized screening, alongside refining non-invasive detection of circulating methylation signatures, holds substantial promise for translating these molecular insights into tangible clinical advances for cardiovascular disease prevention and treatment.
Frontiers of Medicine
Experimental study
Not applicable
Roles of different methylation modifications in cardiovascular disease
15-Dec-2025