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Understanding the regulatory mechanisms underlying gene expression of the adult injured heart is essential for treatment and prevention of heart failure. Since the adult myocardium has poor capacity to regenerate itself, several cell-based trials failed to effectively trigger myocardiogenesis ex novo. Recently, modulation of transcriptional and post-transcriptional activity in resident cardiac cells have been shown to govern the temporal patterns of gene expression in the heart exposed to different type of microenvironment without changing DNA sequence. Several factors that enrich the interstitial microenvironment (i.e.: oxygen free radicals, growth/transcriptional factors and microRNAs) condition the magnitude of gene reprogramming of cells through the activation of promoters or gene silencing. The most common epigenetic changes that alter cardiac physiological traits include: DNA methylation, histone modifications and the RNA-based modifications. The epigenetic state determines the threshold of stress tolerance in adult cardiac cells, induces matrix turnover and angiogenesis, promotes cardiomyocytes differentiation as well as proliferation. All the aforementioned features have an impact on the magnitude of myocardial regeneration process and are epigenetically modulated by endogenous factors. Our review summarizes the epigenetic pathways that underpin endogenous myocardial regeneration and are therapeutic candidates for heart failure.

The adult myocardium has limited capacity to preserve, renew or rejuvenate itself. The local microenvironment may induce epigenetic changes affecting the survival, proliferation, function and senescence of cardiac cells at rest and following the exposure to different stressors. The cellular response to microenvironment is characterized by the release of ions, oxygen free radicals, auto/paracrine factors and RNAs that drive the magnitude of gene reprogramming through the interaction with specific promoters. The epigenetic alterations may act at transcriptional and post-transcriptional level and change cardiac physiological traits. The abnormal DNA methylation underlies the progressive decay of contractile function and the angiogenic ability; while, the histone acetylation promotes the survival, function and proliferation of cardiac cells in the presence of ischemic microenvironment. At least, the expression and secretion of microRNAs and long noncoding RNAs may regulate the threshold to stress tolerance of adult cardiac cells and induce the matrix turnover as well. Natural or synthetic active compounds effectively modulate the epigenetic state of cardiac cells. Plant foods contain many active compounds with epigenetic properties and might assume a clinical significance as natural cardiac regenerators or rejuvenators. Our review describes novel epigenetic mechanisms that underpin myocardial remodeling, repair/ regeneration or senescence in order to support the development of most effective and reproducible rescue therapy of adult heart.