Epigenetics and precision medicine in cardiovascular patients: from basic concepts to the clinical arena

Epidrugs in the clinical management of atherosclerosis: Mechanisms, challenges and promises

Atherosclerosis is a complex and multigenic pathology associated with significant epigenetic reprogramming. Traditional factors (age, sex, obesity, hyperglycaemia, dyslipidaemia, hypertension) and non-traditional factors (foetal indices, microbiome alteration, clonal hematopoiesis, air pollution, sleep disorders) induce endothelial dysfunction, resulting in reduced vascular tone and increased vascular permeability, inflammation and shear stress. These factors induce paracrine and autocrine interactions between several cell types, including vascular smooth muscle cells, endothelial cells, monocytes/macrophages, dendritic cells and T cells. Such cellular interactions lead to tissue-specific epigenetic reprogramming regulated by DNA methylation, histone modifications and microRNAs, which manifests in atherosclerosis. Our review outlines epigenetic signatures during atherosclerosis, which are viewed as potential clinical biomarkers that may be adopted as new therapeutic targets. Additionally, we emphasize epigenetic modifiers referred to as 'epidrugs' as potential therapeutic molecules to correct gene expression patterns and restore vascular homeostasis during atherosclerosis. Further, we suggest nanomedicine-based strategies involving the use of epidrugs, which may selectively target cells in the atherosclerotic microenvironment and reduce off-target effects.

Advantageous early-life environments cushion the genetic risk for ischemic heart disease

In one of the first papers on the impact of early-life conditions on individuals' health in older age, Barker and Osmond [Lancet, 327, 1077-1081 (1986)] show a strong positive relationship between infant mortality rates in the 1920s and ischemic heart disease in the 1970s. We merge historical data on infant mortality rates to 370,000 individual records in the UK Biobank using information on local area and year of birth. We replicate the association between the early-life infant mortality rate and later-life ischemic heart disease in our sample. We then go "beyond Barker," by showing considerable genetic heterogeneity in this association that is robust to within-area as well as within-family analyses. We find no association between the polygenic index and heart disease in areas with the lowest infant mortality rates, but a strong positive relationship in areas characterized by high infant mortality. These findings suggest that advantageous environments can cushion one's genetic disease risk.

Obstructive sleep apnea hypopnea syndrome and vascular lesions: An update on what we currently know

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is the most prevalent sleep and respiratory disorder. This syndrome can induce severe cardiovascular and cerebrovascular complications, and intermittent hypoxia is a pivotal contributor to this damage. Vascular pathology is closely associated with the impairment of target organs, marking a focal point in current research. Vascular lesions are the fundamental pathophysiological basis of multiorgan ailments and indicate a shared pathogenic mechanism among common cardiovascular and cerebrovascular conditions, suggesting their importance as a public health concern. Increasing evidence shows a strong correlation between OSAHS and vascular lesions. Previous studies predominantly focused on the pathophysiological alterations in OSAHS itself, such as intermittent hypoxia and fragmented sleep, leading to vascular disruptions. This review aims to delve deeper into the vascular lesions affected by OSAHS by examining the microscopic pathophysiological mechanisms involved. Emphasis has been placed on examining how OSAHS induces vascular lesions through disruptions in the endothelial barrier, metabolic dysregulation, cellular phenotype alterations, neuroendocrine irregularities, programmed cell death, vascular inflammation, oxidative stress and epigenetic modifications. This review examines the epidemiology and associated risk factors for OSAHS and vascular diseases and subsequently describes the existing evidence on vascular lesions induced by OSAHS in the cardiovascular, cerebrovascular, retinal, renal and reproductive systems. A detailed account of the current research on the pathophysiological mechanisms mediating vascular lesions caused by OSAHS is provided, culminating in a discussion of research advancements in therapeutic modalities to mitigate OSAHS-related vascular lesions and the implications of these treatment strategies.

RNA-mediated epigenetic regulation in exercised heart: Mechanisms and opportunities for intervention

Physical exercise has been widely acknowledged as a beneficial lifestyle alteration and a potent non-pharmacological treatment for heart disease. Extensive investigations have revealed the beneficial effects of exercise on the heart and the underlying mechanisms involved. Exercise is considered one of the key factors that can lead to epigenetic alterations. The increasing number of identified molecules in the exercised heart has led to many studies in recent years that have explored the cellular function of ncRNAs and RNA modifications in the heart. Investigating the regulatory role of RNA-mediated epigenetic regulation in exercised hearts will contribute to the development of therapeutic strategies for the management of heart diseases. This review aims to summarize the positive impact of exercise on cardiac health. We will first provide an overview of the mechanisms through which exercise offers protection to the heart. Subsequently, we will delve into the current understanding of ncRNAs, specifically miRNAs, lncRNAs, and circRNAs, as well as RNA modification, focusing on RNA m6A and RNA A-to-I editing, and how they contribute to exercise-induced benefits for the heart. Lastly, we will explore the emerging therapeutic strategies that utilize exercise-mediated RNA epigenetic regulation in the treatment of heart diseases, while also addressing the challenges faced in this field.

Repressive H3K27me3 drives hyperglycemia-induced oxidative and inflammatory transcriptional programs in human endothelium

BACKGROUND

Histone modifications play a critical role in chromatin remodelling and regulate gene expression in health and disease. Histone methyltransferases EZH1, EZH2, and demethylases UTX, JMJD3, and UTY catalyse trimethylation of lysine 27 on histone H3 (H3K27me3). This study was designed to investigate whether H3K27me3 triggers hyperglycemia-induced oxidative and inflammatory transcriptional programs in the endothelium.

METHODS

We studied human aortic endothelial cells exposed to high glucose (HAEC) or isolated from individuals with diabetes (D-HAEC). RT-qPCR, immunoblotting, chromatin immunoprecipitation (ChIP-qPCR), and confocal microscopy were performed to investigate the role of H3K27me3. We determined superoxide anion (O2-) production by ESR spectroscopy, NF-κB binding activity, and monocyte adhesion. Silencing/overexpression and pharmacological inhibition of chromatin modifying enzymes were used to modulate H3K27me3 levels. Furthermore, isometric tension studies and immunohistochemistry were performed in aorta from wild-type and db/db mice.

RESULTS

Incubation of HAEC to high glucose showed that upregulation of EZH2 coupled to reduced demethylase UTX and JMJD3 was responsible for the increased H3K27me3. ChIP-qPCR revealed that repressive H3K27me3 binding to superoxide dismutase and transcription factor JunD promoters is involved in glucose-induced O2- generation. Indeed, loss of JunD transcriptional inhibition favours NOX4 expression. Furthermore, H3K27me3-driven oxidative stress increased NF-κB p65 activity and downstream inflammatory genes. Interestingly, EZH2 inhibitor GSK126 rescued these endothelial derangements by reducing H3K27me3. We also found that H3K27me3 epigenetic signature alters transcriptional programs in D-HAEC and aortas from db/db mice.

CONCLUSIONS

EZH2-mediated H3K27me3 represents a key epigenetic driver of hyperglycemia-induced endothelial dysfunction. Targeting EZH2 may attenuate oxidative stress and inflammation and, hence, prevent vascular disease in diabetes.

Epigenetic biomarkers for disease susceptibility and preventative medicine

The development of molecular biomarkers for disease makes it possible for preventative medicine approaches to be considered. Therefore, therapeutics, treatments, or clinical management can be used to delay or prevent disease development. The problem with genetic mutations as biomarkers is the low frequency with genome-wide association studies (GWASs), generally at best a 1% association of the patients with the disease. In contrast, epigenetic alterations have a high-frequency association of greater than 90%-95% of individuals with pathology in epigenome-wide association studies (EWASs). A wide variety of human diseases have been shown to have epigenetic biomarkers that are disease specific and that detect pathology susceptibility. This review is focused on the epigenetic biomarkers for disease susceptibility, and it distinct from the large literature on epigenetics of disease etiology or progression. The development of efficient epigenetic biomarkers for disease susceptibility will facilitate a paradigm shift from reactionary medicine to preventative medicine.

Traditional Therapeutics and Potential Epidrugs for CVD: Why Not Both?

Cardiovascular disease (CVD) is the leading cause of death worldwide. In addition to the high mortality rate, people suffering from CVD often endure difficulties with physical activities and productivity that significantly affect their quality of life. The high prevalence of debilitating risk factors such as obesity, type 2 diabetes mellitus, smoking, hypertension, and hyperlipidemia only predicts a bleak future. Current traditional CVD interventions offer temporary respite; however, they compound the severe economic strain of health-related expenditures. Furthermore, these therapeutics can be prescribed indefinitely. Recent advances in the field of epigenetics have generated new treatment options by confronting CVD at an epigenetic level. This involves modulating gene expression by altering the organization of our genome rather than altering the DNA sequence itself. Epigenetic changes are heritable, reversible, and influenced by environmental factors such as medications. As CVD is physiologically and pathologically diverse in nature, epigenetic interventions can offer a ray of hope to replace or be combined with traditional therapeutics to provide the prospect of addressing more than just the symptoms of CVD. This review discusses various risk factors contributing to CVD, perspectives of current traditional medications in practice, and a focus on potential epigenetic therapeutics to be used as alternatives.

Cardiac Fibrosis in heart failure: Focus on non-invasive diagnosis and emerging therapeutic strategies

Heart failure is a leading cause of mortality and hospitalization worldwide. Cardiac fibrosis, resulting from the excessive deposition of collagen fibers, is a common feature across the spectrum of conditions converging in heart failure. Eventually, either reparative or reactive in nature, in the long-term cardiac fibrosis contributes to heart failure development and progression and is associated with poor clinical outcomes. Despite this, specific cardiac antifibrotic therapies are lacking, making cardiac fibrosis an urgent unmet medical need. In this context, a better patient phenotyping is needed to characterize the heterogenous features of cardiac fibrosis to advance toward its personalized management. In this review, we will describe the different phenotypes associated with cardiac fibrosis in heart failure and we will focus on the potential usefulness of imaging techniques and circulating biomarkers for the non-invasive characterization and phenotyping of this condition and for tracking its clinical impact. We will also recapitulate the cardiac antifibrotic effects of existing heart failure and non-heart failure drugs and we will discuss potential strategies under preclinical development targeting the activation of cardiac fibroblasts at different levels, as well as targeting additional extracardiac processes.

Research progress on post-translational modification of proteins and cardiovascular diseases

Cardiovascular diseases (CVDs) such as atherosclerosis, myocardial remodeling, myocardial ischemia-reperfusion (I/R) injury, heart failure, and oxidative stress are among the greatest threats to human health worldwide. Cardiovascular pathogenesis has been studied for decades, and the influence of epigenetic changes on CVDs has been extensively studied. Post-translational modifications (PTMs), including phosphorylation, glycosylation, methylation, acetylation, ubiquitination, ubiquitin-like and nitrification, play important roles in the normal functioning of the cardiovascular system. Over the past decade, with the application of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), an increasing number novel acylation modifications have been discovered, including propionylation, crotonylation, butyrylation, succinylation, lactylation, and isonicotinylation. Each change in protein conformation has the potential to alter protein function and lead to CVDs, and this process is usually reversible. This article summarizes the mechanisms underlying several common PTMs involved in the occurrence and development of CVDs.

Mitochondrial epigenetics in aging and cardiovascular diseases

Mitochondria are cellular organelles which generate adenosine triphosphate (ATP) molecules for the maintenance of cellular energy through the oxidative phosphorylation. They also regulate a variety of cellular processes including apoptosis and metabolism. Of interest, the inner part of mitochondria-the mitochondrial matrix-contains a circular molecule of DNA (mtDNA) characterised by its own transcriptional machinery. As with genomic DNA, mtDNA may also undergo nucleotide mutations that have been shown to be responsible for mitochondrial dysfunction. During physiological aging, the mitochondrial membrane potential declines and associates with enhanced mitophagy to avoid the accumulation of damaged organelles. Moreover, if the dysfunctional mitochondria are not properly cleared, this could lead to cellular dysfunction and subsequent development of several comorbidities such as cardiovascular diseases (CVDs), diabetes, respiratory and cardiovascular diseases as well as inflammatory disorders and psychiatric diseases. As reported for genomic DNA, mtDNA is also amenable to chemical modifications, namely DNA methylation. Changes in mtDNA methylation have shown to be associated with altered transcriptional programs and mitochondrial dysfunction during aging. In addition, other epigenetic signals have been observed in mitochondria, in particular the interaction between mtDNA methylation and non-coding RNAs. Mitoepigenetic modifications are also involved in the pathogenesis of CVDs where oxygen chain disruption, mitochondrial fission, and ROS formation alter cardiac energy metabolism leading to hypertrophy, hypertension, heart failure and ischemia/reperfusion injury. In the present review, we summarize current evidence on the growing importance of epigenetic changes as modulator of mitochondrial function in aging. A better understanding of the mitochondrial epigenetic landscape may pave the way for personalized therapies to prevent age-related diseases.

SIRT6 is an epigenetic repressor of thoracic aortic aneurysms via inhibiting inflammation and senescence

Thoracic aortic aneurysms (TAAs) develop asymptomatically and are characterized by dilatation of the aorta. This is considered a life-threating vascular disease due to the risk of aortic rupture and without effective treatments. The current understanding of the pathogenesis of TAA is still limited, especially for sporadic TAAs without known genetic mutation. Sirtuin 6 (SIRT6) expression was significantly decreased in the tunica media of sporadic human TAA tissues. Genetic knockout of Sirt6 in mouse vascular smooth muscle cells accelerated TAA formation and rupture, reduced survival, and increased vascular inflammation and senescence after angiotensin II infusion. Transcriptome analysis identified interleukin (IL)-1β as a pivotal target of SIRT6, and increased IL-1β levels correlated with vascular inflammation and senescence in human and mouse TAA samples. Chromatin immunoprecipitation revealed that SIRT6 bound to the Il1b promoter to repress expression partly by reducing the H3K9 and H3K56 acetylation. Genetic knockout of Il1b or pharmacological inhibition of IL-1β signaling with the receptor antagonist anakinra rescued Sirt6 deficiency mediated aggravation of vascular inflammation, senescence, TAA formation and survival in mice. The findings reveal that SIRT6 protects against TAA by epigenetically inhibiting vascular inflammation and senescence, providing insight into potential epigenetic strategies for TAA treatment.

Basic Pathogenic Mechanisms and Epigenetic Players Promoted by Extracellular Vesicles in Vascular Damage

Both progression from the early pathogenic events to clinically manifest cardiovascular diseases (CVD) and cancer impact the integrity of the vascular system. Pathological vascular modifications are affected by interplay between endothelial cells and their microenvironment. Soluble factors, extracellular matrix molecules and extracellular vesicles (EVs) are emerging determinants of this network that trigger specific signals in target cells. EVs have gained attention as package of molecules with epigenetic reversible activity causing functional vascular changes, but their mechanisms are not well understood. Valuable insights have been provided by recent clinical studies, including the investigation of EVs as potential biomarkers of these diseases. In this paper, we review the role and the mechanism of exosomal epigenetic molecules during the vascular remodeling in coronary heart disease as well as in cancer-associated neoangiogenesis.

Mitochondrial miRNA as epigenomic signatures: Visualizing aging-associated heart diseases through a new lens

Aging bears many hard knocks, but heart disorders earn a particular allusion, being the most widespread. Cardiovascular diseases (CVDs) are becoming the biggest concern to mankind due to sundry health conditions directly or indirectly related to heart-linked abnormalities. Scientists know that mitochondria play a critical role in the pathophysiology of cardiac diseases. Both environment and genetics play an essential role in modulating and controlling mitochondrial functions. Even a minor abnormality may prove detrimental to heart function. Advanced age combined with an unhealthy lifestyle can cause most cardiomyocytes to be replaced by fibrotic tissue which upsets the conducting system and leads to arrhythmias. An aging heart encounters far more heart-associated comorbidities than a young heart. Many state-of-the-art technologies and procedures are already being used to prevent and treat heart attacks worldwide. However, it remains a mystery when this heart bomb would explode because it lacks an alarm. This calls for a novel and effective strategy for timely diagnosis and a sure-fire treatment. This review article provides a comprehensive overture of prospective potentials of mitochondrial miRNAs that predict complicated and interconnected pathways concerning heart ailments and signature compilations of relevant miRNAs as biomarkers to plot the role of miRNAs in epigenomics. This article suggests that analysis of DNA methylation patterns in age-associated heart diseases may determine age-impelled biomarkers of heart disease.

Emerging epigenetic therapies of cardiac fibrosis and remodelling in heart failure: from basic mechanisms to early clinical development

Cardiovascular diseases and specifically heart failure (HF) impact global health and impose a significant economic burden on society. Despite current advances in standard of care, the risks for death and readmission of HF patients remain unacceptably high and new therapeutic strategies to limit HF progression are highly sought. In disease settings, persistent mechanical or neurohormonal stress to the myocardium triggers maladaptive cardiac remodelling, which alters cardiac function and structure at both the molecular and cellular levels. The progression and magnitude of maladaptive cardiac remodelling ultimately leads to the development of HF. Classical therapies for HF are largely protein-based and mostly are targeted to ameliorate the dysregulation of neuroendocrine pathways and halt adverse remodelling. More recently, investigation of novel molecular targets and the application of cellular therapies, epigenetic modifications, and regulatory RNAs has uncovered promising new avenues to address HF. In this review, we summarize the current knowledge on novel cellular and epigenetic therapies and focus on two non-coding RNA-based strategies that reached the phase of early clinical development to counteract cardiac remodelling and HF. The current status of the development of translating those novel therapies to clinical practice, limitations, and future perspectives are additionally discussed.

DNA Methylation Is a Potential Biomarker for Cardiometabolic Health in Mexican Children and Adolescents

DNA methylation (DNAm) is a plausible mechanism underlying cardiometabolic abnormalities, but evidence is limited among youth. This analysis included 410 offspring of the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) birth cohort followed up to two time points in late childhood/adolescence. At Time 1, DNAm was quantified in blood leukocytes at long interspersed nuclear elements (LINE-1), H19, and 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD-2), and at Time 2 in peroxisome proliferator-activated receptor alpha (PPAR-α). At each time point, cardiometabolic risk factors were assessed including lipid profiles, glucose, blood pressure, and anthropometry. Linear mixed effects models were used for LINE-1, H19, and 11β-HSD-2 to account for the repeated-measure outcomes. Linear regression models were conducted for the cross-sectional association between PPAR-α with the outcomes. DNAm at LINE-1 was associated with log glucose at site 1 [β = -0.029, p = 0.0006] and with log high-density lipoprotein cholesterol at site 3 [β = 0.063, p = 0.0072]. 11β-HSD-2 DNAm at site 4 was associated with log glucose (β = -0.018, p = 0.0018). DNAm at LINE-1 and 11β-HSD-2 was associated with few cardiometabolic risk factors among youth in a locus-specific manner. These findings underscore the potential for epigenetic biomarkers to increase our understanding of cardiometabolic risk earlier in life.

Microfluidics for diagnosis and treatment of cardiovascular disease

Cardiovascular disease (CVD), a type of circulatory system disease related to the lesions of the cardiovascular system, has become one of the main diseases that endanger human health. Currently, the clinical diagnosis of most CVDs relies on a combination of imaging technology and blood biochemical test. However, the existing technologies for diagnosis of CVDs still have limitations in terms of specificity, detection range, and cost. In order to break through the current bottleneck, microfluidic with the advantages of low cost, simple instruments and easy integration, has been developed to play an important role in the early prevention, diagnosis and treatment of CVDs. Here, we have reviewed the recent various applications of microfluidic in the clinical diagnosis and treatment of CVDs, including microfluidic devices for detecting CVD markers, the cardiovascular models based on microfluidic, and the microfluidic used for CVDs drug screening and delivery. In addition, we have briefly looked forward to the prospects and challenges of microfluidics in diagnosis and treatment of CVDs.

Endothelial Dysfunction and Chronic Inflammation: The Cornerstones of Vascular Alterations in Age-Related Diseases

Vascular diseases of the elderly are a topic of enormous interest in clinical practice, as they have great epidemiological significance and lead to ever-increasing healthcare expenditures. The mechanisms underlying these pathologies have been increasingly characterized over the years. It has emerged that endothelial dysfunction and chronic inflammation play a diriment role among the most relevant pathophysiological mechanisms. As one can easily imagine, various processes occur during aging, and several pathways undergo irreversible alterations that can promote the decline and aberrations that trigger the diseases above. Endothelial dysfunction and aging of circulating and resident cells are the main characteristics of the aged organism; they represent the framework within which an enormous array of molecular abnormalities occur and contribute to accelerating and perpetuating the decline of organs and tissues. Recognizing and detailing each of these dysfunctional pathways is helpful for therapeutic purposes, as it allows one to hypothesize the possibility of tailoring interventions to the damaged mechanism and hypothetically limiting the cascade of events that drive the onset of these diseases. With this paper, we have reviewed the scientific literature, analysing the pathophysiological basis of the vascular diseases of the elderly and pausing to reflect on attempts to interrupt the vicious cycle that connotes the diseases of aging, laying the groundwork for therapeutic reasoning and expanding the field of scientific research by moving from a solid foundation.

Epigenetics in the primary and secondary prevention of cardiovascular disease: influence of exercise and nutrition

Increasing evidence links changes in epigenetic systems, such as DNA methylation, histone modification, and non-coding RNA expression, to the occurrence of cardiovascular disease (CVD). These epigenetic modifications can change genetic function under influence of exogenous stimuli and can be transferred to next generations, providing a potential mechanism for inheritance of behavioural intervention effects. The benefits of exercise and nutritional interventions in the primary and secondary prevention of CVD are well established, but the mechanisms are not completely understood. In this review, we describe the acute and chronic epigenetic effects of physical activity and dietary changes. We propose exercise and nutrition as potential triggers of epigenetic signals, promoting the reshaping of transcriptional programmes with effects on CVD phenotypes. Finally, we highlight recent developments in epigenetic therapeutics with implications for primary and secondary CVD prevention.

Pharmacological Inhibition of Lysine-Specific Demethylase 1A Reduces Atherosclerotic Lesion Formation in Apolipoprotein E-Deficient Mice by a Mechanism Involving Decreased Oxidative Stress and Inflammation; Potential Implications in Human Atherosclerosis

Dysregulated epigenetic mechanisms promote transcriptomic and phenotypic alterations in cardiovascular diseases. The role of histone methylation-related pathways in atherosclerosis is largely unknown. We hypothesize that lysine-specific demethylase 1A (LSD1/KDM1A) regulates key molecular effectors and pathways linked to atherosclerotic plaque formation. Human non-atherosclerotic and atherosclerotic tissue specimens, ApoE-/- mice, and in vitro polarized macrophages (Mac) were examined. Male ApoE-/- mice fed a normal/atherogenic diet were randomized to receive GSK2879552, a highly specific LSD1 inhibitor, or its vehicle, for 4 weeks. The mRNA and protein expression levels of LSD1/KDM1A were significantly elevated in atherosclerotic human carotid arteries, atherosclerotic aortas of ApoE-/- mice, and M1-Mac. Treatment of ApoE-/- mice with GSK2879552 significantly reduced the extent of atherosclerotic lesions and the aortic expression of NADPH oxidase subunits (Nox1/2/4, p22phox) and 4-hydroxynonenal-protein adducts. Concomitantly, the markers of immune cell infiltration and vascular inflammation were significantly decreased. LSD1 blockade down-regulated the expression of genes associated with Mac pro-inflammatory phenotype. Nox subunit transcript levels were significantly elevated in HEK293 reporter cells overexpressing LSD1. In experimental atherosclerosis, LSD1 mediates the up-regulation of molecular effectors connected to oxidative stress and inflammation. Together, these data indicate that LSD1-pharmacological interventions are novel targets for supportive therapeutic strategies in atherosclerosis.

Modelling metabolic diseases and drug response using stem cells and organoids

Metabolic diseases, including obesity, diabetes mellitus and cardiovascular disease, are a major threat to health in the modern world, but efforts to understand the underlying mechanisms and develop rational treatments are limited by the lack of appropriate human model systems. Notably, advances in stem cell and organoid technology allow the generation of cellular models that replicate the histological, molecular and physiological properties of human organs. Combined with marked improvements in gene editing tools, human stem cells and organoids provide unprecedented systems for studying mechanisms of metabolic diseases. Here, we review progress made over the past decade in the generation and use of stem cell-derived metabolic cell types and organoids in metabolic disease research, especially obesity and liver diseases. In particular, we discuss the limitations of animal models and the advantages of stem cells and organoids, including their application to metabolic diseases. We also discuss mechanisms of drug action, understanding the efficacy and toxicity of existing therapies, screening for new treatments and pursuing personalized therapies. We highlight the potential of combining stem cell-derived organoids with gene editing and functional genomics to revolutionize the approach to finding treatments for metabolic diseases.

DNA methylation alternation in Stanford- A acute aortic dissection

Background

Acute aortic dissection (AAD) is a life-threatening cardiovascular disease. Recent studies have shown that DNA methylation may be associated with the pathological mechanism of AAD, but the panorama of DNA methylation needs to be explored.

Methods

DNA methylation patterns were screened using Infinium Human Methylation 450 K BeadChip in the aortic tissues from 4 patients with Stanford-A AAD and 4 controls. Gene enrichment was analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and gene ontology (GO). DNA methylation levels of candidate genes were determined by pyrosequencing in the replication cohort including 16 patients with AAD and 7 controls. Protein expression level of candidate gene was assessed by Western blot.

Results

A total of 589 differentially methylated positions including 315 hypomethylated and 274 hypermethylated positions were found in AAD group. KEGG analysis demonstrated that differentially methylated position-associated genes were enriched in MAPK signaling pathway, TNF signaling pathway and apoptosis pathway, et al. GO analysis demonstrated that differentially methylated position-associated genes were enriched in protein binding, angiogenesis and heart development et al. The differential DNA methylation in five key genes, including Fas, ANGPT2, DUSP6, FARP1 and CARD6, was authenticated in the independent replication cohort. The protein expression level of the Fas was increased by 1.78 times, indicating the possible role of DNA methylation in regulation of gene expression.

Conclusion

DNA methylation was markedly changed in the aortic tissues of Stanford-A AAD and associated with gene dysregulation, involved in AAD progression.

Supplementary Information

The online version contains supplementary material available at10.1186/s12872-022-02882-5.

Epi-Drugs in Heart Failure

Unveiling the secrets of genome's flexibility does not only foster new research in the field, but also gives rise to the exploration and development of novel epigenetic-based therapies as an approach to alleviate disease phenotypes. A better understanding of chromatin biology (DNA/histone complexes) and non-coding RNAs (ncRNAs) has enabled the development of epigenetic drugs able to modulate transcriptional programs implicated in cardiovascular diseases. This particularly applies to heart failure, where epigenetic networks have shown to underpin several pathological features, such as left ventricular hypertrophy, fibrosis, cardiomyocyte apoptosis and microvascular dysfunction. Targeting epigenetic signals might represent a promising approach, especially in patients with heart failure with preserved ejection fraction (HFpEF), where prognosis remains poor and breakthrough therapies have yet to be approved. In this setting, epigenetics can be employed for the development of customized therapeutic approaches thus paving the way for personalized medicine. Even though the beneficial effects of epi-drugs are gaining attention, the number of epigenetic compounds used in the clinical practice remains low suggesting that more selective epi-drugs are needed. From DNA-methylation changes to non-coding RNAs, we can establish brand-new regulations for drug targets with the aim of restoring healthy epigenomes and transcriptional programs in the failing heart. In the present review, we bring the timeline of epi-drug discovery and development, thus highlighting the emerging role of epigenetic therapies in heart failure.

Studying Epigenetics of Cardiovascular Diseases on Chip Guide

Epigenetics is defined as the study of inheritable changes in the gene expressions and phenotypes that occurs without altering the normal DNA sequence. These changes are mainly due to an alteration in chromatin or its packaging, which changes the DNA accessibility. DNA methylation, histone modification, and noncoding or microRNAs can best explain the mechanism of epigenetics. There are various DNA methylated enzymes, histone-modifying enzymes, and microRNAs involved in the cause of various CVDs (cardiovascular diseases) such as cardiac hypertrophy, heart failure, and hypertension. Moreover, various CVD risk factors such as diabetes mellitus, hypoxia, aging, dyslipidemia, and their epigenetics are also discussed together with CVDs such as CHD (coronary heart disease) and PAH (pulmonary arterial hypertension). Furthermore, different techniques involved in epigenetic chromatin mapping are explained. Among these techniques, the ChIP-on-chip guide is explained with regard to its role in cardiac hypertrophy, a final form of heart failure. This review focuses on different epigenetic factors that are involved in causing cardiovascular diseases.

Epigenetic remodeling in heart failure with preserved ejection fraction

PURPOSE OF REVIEW

In this review, we critically address the role of epigenetic processing and its therapeutic modulation in heart failure with preserved ejection fraction (HFpEF).

RECENT FINDINGS

HFpEF associates with a poor prognosis and the identification of novel molecular targets and therapeutic approaches are in high demand. Emerging evidence indicates a key involvement of epigenetic signals in the regulation of transcriptional programs underpinning features of HFpEF. The growing understanding of chromatin dynamics has led to the development of selective epigenetic drugs able to reset transcriptional changes thus delaying or preventing the progression toward HFpEF. Epigenetic information in the setting of HFpEF can be employed to: (i) dissect novel epigenetic networks and chromatin marks contributing to HFpEF; (ii) unveil circulating and cell-specific epigenetic biomarkers; (iii) build predictive models by using computational epigenetics and deep machine learning; (iv) develop new chromatin modifying drugs for personalized management of HFpEF.

SUMMARY

Acquired epigenetic signatures during the lifetime can contribute to derail molecular pathways involved in HFpEF. A scrutiny investigation of the individual epigenetic landscape will offer opportunities to develop personalized epigenetic biomarkers and therapies to fight HFpEF in the decades to come.

The BET Protein Inhibitor Apabetalone Rescues Diabetes-Induced Impairment of Angiogenic Response by Epigenetic Regulation of Thrombospondin-1

Aims: Therapeutic modulation of blood vessel growth holds promise for the prevention of limb ischemia in diabetic (DM) patients with peripheral artery disease (PAD). Epigenetic changes, namely, posttranslational histone modifications, participate in angiogenic response suggesting that chromatin-modifying drugs could be beneficial in this setting. Apabetalone (APA), a selective inhibitor of bromodomain (BRD) and bromodomain and extraterminal containing protein family (BET) proteins, prevents bromodomain-containing protein 4 (BRD4) interactions with chromatin thus modulating transcriptional programs in different organs. We sought to investigate whether APA affects angiogenic response in diabetes. Results: Compared with vehicle, APA restored tube formation and migration in human aortic endothelial cells (HAECs) exposed to high-glucose (HG) levels. Expression profiling of angiogenesis genes showed that APA prevents HG-induced upregulation of the antiangiogenic molecule thrombospondin-1 (THBS1). ChIP-seq and chromatin immunoprecipitation (ChIP) assays in HG-treated HAECs showed the enrichment of both BRD4 and active marks (H3K27ac) on THBS1 promoter, whereas BRD4 inhibition by APA prevented chromatin accessibility and THBS1 transcription. Mechanistically, we show that THBS1 inhibits angiogenesis by suppressing vascular endothelial growth factor A (VEGFA) signaling, while APA prevents these detrimental changes. In diabetic mice with hind limb ischemia, epigenetic editing by APA restored the THBS1/VEGFA axis, thus improving limb vascularization and perfusion, compared with vehicle-treated animals. Finally, epigenetic regulation of THBS1 by BRD4/H3K27ac was also reported in DM patients with PAD compared with nondiabetic controls. Innovation: This is the first study showing that BET protein inhibition by APA restores angiogenic response in experimental diabetes. Conclusions: Our findings set the stage for preclinical studies and exploratory clinical trials testing APA in diabetic PAD. Antioxid. Redox Signal. 36, 667-684.

Epigenetics in Precision Nutrition

Precision nutrition is an emerging area of nutrition research, with primary focus on the individual variability in response to dietary and lifestyle factors, which are mainly determined by an individual’s intrinsic variations, such as those in genome, epigenome, and gut microbiome. The current research on precision nutrition is heavily focused on genome and gut microbiome, while epigenome (DNA methylation, non-coding RNAs, and histone modification) is largely neglected. The epigenome acts as the interface between the human genome and environmental stressors, including diets and lifestyle. Increasing evidence has suggested that epigenetic modifications, particularly DNA methylation, may determine the individual variability in metabolic health and response to dietary and lifestyle factors and, therefore, hold great promise in discovering novel markers for precision nutrition and potential targets for precision interventions. This review summarized recent studies on DNA methylation with obesity, diabetes, and cardiovascular disease, with more emphasis put in the relations of DNA methylation with nutrition and diet/lifestyle interventions. We also briefly reviewed other epigenetic events, such as non-coding RNAs, in relation to human health and nutrition, and discussed the potential role of epigenetics in the precision nutrition research.

Biophysics is reshaping our perception of the epigenome: from DNA-level to high-throughput studies

Epigenetic research holds great promise to advance our understanding of biomarkers and regulatory processes in health and disease. An increasing number of new approaches, ranging from molecular to biophysical analyses, enable identifying epigenetic changes on the level of a single gene or the whole epigenome. The aim of this review is to highlight how the field is shifting from completely molecular-biology-driven solutions to multidisciplinary strategies including more reliance on biophysical analysis tools. Biophysics not only offers technical advancements in imaging or structure analysis but also helps to explore regulatory interactions. New computational methods are also being developed to meet the demand of growing data volumes and their processing. Therefore, it is important to capture these new directions in epigenetics from a biophysical perspective and discuss current challenges as well as multiple applications of biophysical methods and tools. Specifically, we gradually introduce different biophysical research methods by first considering the DNA-level information and eventually higher-order chromatin structures. Moreover, we aim to highlight that the incorporation of bioinformatics, machine learning, and artificial intelligence into biophysical analysis allows gaining new insights into complex epigenetic processes. The gained understanding has already proven useful in translational and clinical research providing better patient stratification options or new therapeutic insights. Together, this offers a better readiness to transform bench-top experiments into industrial high-throughput applications with a possibility to employ developed methods in clinical practice and diagnostics.

Epigenetic modification in alcohol use disorder and alcoholic cardiomyopathy: From pathophysiology to therapeutic opportunities

Alcohol consumption prompts detrimental psychological, pathophysiological and health issues, representing one of the major causes of death worldwide. Alcohol use disorder (AUD), which is characterized by compulsive alcohol intake and loss of control over alcohol usage, arises from a complex interplay between genetic and environmental factors. More importantly, long-term abuse of alcohol is often tied with unfavorable cardiac remodeling and contractile alterations, a cadre of cardiac responses collectively known as alcoholic cardiomyopathy (ACM). Recent evidence has denoted a pivotal role for ethanol-triggered epigenetic modifications, the interface between genome and environmental cues, in the organismal and cellular responses to ethanol exposure. To-date, three major epigenetic mechanisms (DNA methylation, histone modifications, and RNA-based mechanisms) have been identified for the onset and development of AUD and ACM. Importantly, these epigenetic changes induced by alcohol may be detectable in the blood, thus offering diagnostic, therapeutic, and prognostic promises of epigenetic markers for AUD and alcoholic complications. In addition, several epigenetic drugs have shown efficacies in the management of alcohol abuse, loss of control for alcohol usage, relapse, drinking-related anxiety and behavior in withdrawal. In this context, medications targeting epigenetic modifications may hold promises for pharmaceutical management of AUD and ACM.

[Personalized medicine in non-communicable diseases: latest advances and future prospects]

Since the human genome was decoded more than 15 years ago, there has been a huge leap forward in the development of genomic and post-genomic technologies. Personalized medicine is engaged in implementing these technologies in clinical practice by developing new methods for risk assessment, diagnosis, and treatment of diseases taking into account individual features of the patient. Significant progress has been achieved in decoding genetic bases of chronic noninfectious diseases; new markers for the risk of complications and targets for effects of drugs are being searched for. This review highlights promising directions in the development of personalized medicine, the problems facing modern scientists, and possible ways to solve them.

PiRNA pathway in the cardiovascular system: a novel regulator of cardiac differentiation, repair and regeneration

Piwi-interacting RNAs (piRNAs) are a novel group of small non-coding RNA molecules with lengths of 21-35 nucleotides, first identified from the germline. PiRNAs and their associated PIWI clade Argonaute proteins constitute a key part of the piRNA pathway, with the best-known biological function to silence transposable elements in germ cells. The piRNA pathway, in fact, is not exclusive to the germline. Somatic functions of piRNAs have been recorded since their first discovery. To date, involvement of the piRNA pathway has been identified within the biological functions of genome rearrangement, epigenetic regulation, protein regulation in the germline and/or the soma transcriptionally or post-transcriptionally. Emerging evidence has shown that the piRNA pathway is essential for the normal function of the cardiovascular system and that its abnormal expression is correlated with cardiovascular dysfunction, although comprehensive roles of the piRNA pathway in the cardiovascular system and underlying mechanisms remain unclear. In this review, we discuss current findings of piRNA pathway expression in cardiac cell types and their potential functions in cardiac differentiation, repair and regeneration, thus providing new insights into cardiovascular disease development associated with the piRNA pathway.

Individual-specific functional epigenomics reveals genetic determinants of adverse metabolic effects of glucocorticoids

Glucocorticoids (GCs) are widely used as anti-inflammatory drugs, but their long-term use has severe metabolic side effects. Here, by treating multiple individual adipose stem cell-derived adipocytes and induced pluripotent stem cell-derived hepatocytes with the potent GC dexamethasone (Dex), we uncovered cell-type-specific and individual-specific GC-dependent transcriptomes and glucocorticoid receptor (GR) cistromes. Individual-specific GR binding could be traced to single-nucleotide polymorphisms (SNPs) that altered the binding motifs of GR or its cooperating factors. We also discovered another set of genetic variants that modulated Dex response through affecting chromatin accessibility or chromatin architecture. Several SNPs that altered Dex-regulated GR binding and gene expression controlled Dex-driven metabolic perturbations. Remarkably, these genetic variations were highly associated with increases in serum glucose, lipids, and body mass in subjects on GC therapy. Knowledge of the genetic variants that predispose individuals to metabolic side effects allows for a precision medicine approach to the use of clinically relevant GCs.

The Role of Computer Skills in Personal Health Record Adoption Among Patients With Heart Disease: Multidimensional Evaluation of Users Versus Nonusers

Background

In the era of precision medicine, it is critical for health communication efforts to prioritize personal health record (PHR) adoption.

Objective

The objective of this study was to describe the characteristics of patients with heart disease that choose to adopt a PHR.

Methods

A total of 79 patients with chronic cardiovascular disease participated in this study: 48 PHR users and 31 nonusers. They completed 5 surveys related to their choice to use or not use the PHR: demographics, patient activation, medication adherence, health literacy, and computer self-efficacy (CSE).

Results

There was a significant difference between users and nonusers in the sociodemographic measure education (P=.04). There was no significant difference between users and nonusers in other sociodemographic measures: age (P=.20), sex (P=.35), ethnicity (P=.43), race (P=.42), and employment (P=.63). There was a significant difference between PHR users and PHR nonusers in CSE (P=.006).

Conclusions

In this study, we demonstrate that sociodemographic characteristics were not an important factor in patients’ use of their PHR, except for education. This study had a small sample size and may not have been large enough to detect differences between groups. Our results did demonstrate that there is a difference between PHR users and nonusers related to their CSE. This work suggests that incorporating CSE into the design of PHRs is critical. The design of patient-facing tools must take into account patients’ preferences and abilities when developing effective user-friendly health information technologies.

Leveraging clinical epigenetics in heart failure with preserved ejection fraction: a call for individualized therapies

Described as the 'single largest unmet need in cardiovascular medicine', heart failure with preserved ejection fraction (HFpEF) remains an untreatable disease currently representing 65% of new heart failure diagnoses. HFpEF is more frequent among women and associates with a poor prognosis and unsustainable healthcare costs. Moreover, the variability in HFpEF phenotypes amplifies complexity and difficulties in the approach. In this perspective, unveiling novel molecular targets is imperative. Epigenetic modifications-defined as changes of DNA, histones, and non-coding RNAs (ncRNAs)-represent a molecular framework through which the environment modulates gene expression. Epigenetic signals acquired over the lifetime lead to chromatin remodelling and affect transcriptional programmes underlying oxidative stress, inflammation, dysmetabolism, and maladaptive left ventricular remodelling, all conditions predisposing to HFpEF. The strong involvement of epigenetic signalling in this setting makes the epigenetic information relevant for diagnostic and therapeutic purposes in patients with HFpEF. The recent advances in high-throughput sequencing, computational epigenetics, and machine learning have enabled the identification of reliable epigenetic biomarkers in cardiovascular patients. Contrary to genetic tools, epigenetic biomarkers mirror the contribution of environmental cues and lifestyle changes and their reversible nature offers a promising opportunity to monitor disease states. The growing understanding of chromatin and ncRNAs biology has led to the development of several Food and Drug Administration approved 'epidrugs' (chromatin modifiers, mimics, anti-miRs) able to prevent transcriptional alterations underpinning left ventricular remodelling and HFpEF. In the present review, we discuss the importance of clinical epigenetics as a new tool to be employed for a personalized management of HFpEF.

Epigenetic Remodeling in Obesity-Related Vascular Disease

Significance: The prevalence of obesity and cardiometabolic phenotypes is alarmingly increasing across the globe and is associated with atherosclerotic vascular complications and high mortality. In spite of multifactorial interventions, vascular residual risk remains high in this patient population, suggesting the need for breakthrough therapies. The mechanisms underpinning obesity-related vascular disease remain elusive and represent an intense area of investigation. Recent Advances: Epigenetic modifications-defined as environmentally induced chemical changes of DNA and histones that do not affect DNA sequence-are emerging as a potent modulator of gene transcription in the vasculature and might significantly contribute to the development of obesity-induced endothelial dysfunction. DNA methylation and histone post-translational modifications cooperate to build complex epigenetic signals, altering transcriptional networks that are implicated in redox homeostasis, mitochondrial function, vascular inflammation, and perivascular fat homeostasis in patients with cardiometabolic disturbances. Critical Issues: Deciphering the epigenetic landscape in the vasculature is extremely challenging due to the complexity of epigenetic signals and their function in regulating transcription. An overview of the most important epigenetic pathways is required to identify potential molecular targets to treat or prevent obesity-related endothelial dysfunction and atherosclerotic disease. This would enable the employment of precision medicine approaches in this setting. Future Directions: Current and future research efforts in this field entail a better definition of the vascular epigenome in obese patients as well as the unveiling of novel, cell-specific chromatin-modifying drugs that are able to erase specific epigenetic signals that are responsible for maladaptive transcriptional alterations and vascular dysfunction in obese patients. Antioxid. Redox Signal. 34, 1165-1199.

Cell-specific epigenetic changes in atherosclerosis

Atherosclerosis is a disease of large and medium arteries that can lead to life-threatening cerebrovascular and cardiovascular consequences such as heart failure and stroke and is a major contributor to cardiovascular-related mortality worldwide. Atherosclerosis development is a complex process that involves specific structural, functional and transcriptional changes in different vascular cell populations at different stages of the disease. The application of single-cell RNA sequencing (scRNA-seq) analysis has discovered not only disease-related cell-specific transcriptomic profiles but also novel subpopulations of cells once thought as homogenous cell populations. Vascular cells undergo specific transcriptional changes during the entire course of the disease. Epigenetics is the instruction-set-architecture in living cells that defines and maintains the cellular identity by regulating the cellular transcriptome. Although different cells contain the same genetic material, they have different epigenomic signatures. The epigenome is plastic, dynamic and highly responsive to environmental stimuli. Modifications to the epigenome are driven by an array of epigenetic enzymes generally referred to as writers, erasers and readers that define cellular fate and destiny. The reversibility of these modifications raises hope for finding novel therapeutic targets for modifiable pathological conditions including atherosclerosis where the involvement of epigenetics is increasingly appreciated. This article provides a critical review of the up-to-date research in the field of epigenetics mainly focusing on in vivo settings in the context of the cellular role of individual vascular cell types in the development of atherosclerosis.

Inflamm-ageing: the role of inflammation in age-dependent cardiovascular disease

The ongoing worldwide increase in life expectancy portends a rising prevalence of age-related cardiovascular (CV) diseases in the coming decades that demands a deeper understanding of their molecular mechanisms. Inflammation has recently emerged as an important contributor for CV disease development. Indeed, a state of chronic sterile low-grade inflammation characterizes older organisms (also known as inflamm-ageing) and participates pivotally in the development of frailty, disability, and most chronic degenerative diseases including age-related CV and cerebrovascular afflictions. Due to chronic activation of inflammasomes and to reduced endogenous anti-inflammatory mechanisms, inflamm-ageing contributes to the activation of leucocytes, endothelial, and vascular smooth muscle cells, thus accelerating vascular ageing and atherosclerosis. Furthermore, inflamm-ageing promotes the development of catastrophic athero-thrombotic complications by enhancing platelet reactivity and predisposing to plaque rupture and erosion. Thus, inflamm-ageing and its contributors or molecular mediators might furnish targets for novel therapeutic strategies that could promote healthy ageing and conserve resources for health care systems worldwide. Here, we discuss recent findings in the pathophysiology of inflamm-ageing, the impact of these processes on the development of age-related CV diseases, results from clinical trials targeting its components and the potential implementation of these advances into daily clinical practice.

From traditional pharmacological towards nucleic acid-based therapies for cardiovascular diseases

Nucleic acid-based therapeutics are currently developed at large scale for prevention and management of cardiovascular diseases (CVDs), since: (i) genetic studies have highlighted novel therapeutic targets suggested to be causal for CVD; (ii) there is a substantial recent progress in delivery, efficacy, and safety of nucleic acid-based therapies; (iii) they enable effective modulation of therapeutic targets that cannot be sufficiently or optimally addressed using traditional small molecule drugs or antibodies. Nucleic acid-based therapeutics include (i) RNA-targeted therapeutics for gene silencing; (ii) microRNA-modulating and epigenetic therapies; (iii) gene therapies; and (iv) genome-editing approaches (e.g. CRISPR-Cas-based): (i) RNA-targeted therapeutics: several large-scale clinical development programmes, using antisense oligonucleotides (ASO) or short interfering RNA (siRNA) therapeutics for prevention and management of CVD have been initiated. These include ASO and/or siRNA molecules to lower apolipoprotein (a) [apo(a)], proprotein convertase subtilisin/kexin type 9 (PCSK9), apoCIII, ANGPTL3, or transthyretin (TTR) for prevention and treatment of patients with atherosclerotic CVD or TTR amyloidosis. (ii) MicroRNA-modulating and epigenetic therapies: novel potential therapeutic targets are continually arising from human non-coding genome and epigenetic research. First microRNA-based therapeutics or therapies targeting epigenetic regulatory pathways are in clinical studies. (iii) Gene therapies: EMA/FDA have approved gene therapies for non-cardiac monogenic diseases and LDL receptor gene therapy is currently being examined in patients with homozygous hypercholesterolaemia. In experimental studies, gene therapy has significantly improved cardiac function in heart failure animal models. (iv) Genome editing approaches: these technologies, such as using CRISPR-Cas, have proven powerful in stem cells, however, important challenges are remaining, e.g. low rates of homology-directed repair in somatic cells such as cardiomyocytes. In summary, RNA-targeted therapies (e.g. apo(a)-ASO and PCSK9-siRNA) are now in large-scale clinical outcome trials and will most likely become a novel effective and safe therapeutic option for CVD in the near future. MicroRNA-modulating, epigenetic, and gene therapies are tested in early clinical studies for CVD. CRISPR-Cas-mediated genome editing is highly effective in stem cells, but major challenges are remaining in somatic cells, however, this field is rapidly advancing.

African genetic diversity and adaptation inform a precision medicine agenda

The deep evolutionary history of African populations, since the emergence of modern humans more than 300,000 years ago, has resulted in high genetic diversity and considerable population structure. Selected genetic variants have increased in frequency due to environmental adaptation, but recent exposures to novel pathogens and changes in lifestyle render some of them with properties leading to present health liabilities. The unique discoverability potential from African genomic studies promises invaluable contributions to understanding the genomic and molecular basis of health and disease. Globally, African populations are understudied, and precision medicine approaches are largely based on data from European and Asian-ancestry populations, which limits the transferability of findings to the continent of Africa. Africa needs innovative precision medicine solutions based on African data that use knowledge and implementation strategies aligned to its climatic, cultural, economic and genomic diversity.

The Epigenome in Atherosclerosis

Emerging evidence suggests the growing importance of "nongenetic factors" in the pathogenesis of atherosclerotic vascular disease. Indeed, the inherited genome determines only part of the risk profile as genomic approaches do not take into account additional layers of biological regulation by "epi"-genetic changes. Epigenetic modifications are defined as plastic chemical changes of DNA/histone complexes which critically affect gene activity without altering the DNA sequence. These modifications include DNA methylation, histone posttranslational modifications, and non-coding RNAs and have the ability to modulate gene expression at both transcriptional and posttranscriptional level. Notably, epigenetic signals are mainly induced by environmental factors (i.e., pollution, smoking, noise) and, once acquired, may be transmitted to the offspring. The inheritance of adverse epigenetic changes may lead to premature deregulation of pathways involved in vascular damage and endothelial dysfunction. Here, we describe the emerging role of epigenetic modifications as fine-tuners of gene transcription in atherosclerosis. Specifically, the following aspects are described in detail: (1) discovery and impact of the epigenome in cardiovascular disease, (2) the epigenetic landscape in atherosclerosis; (3) inheritance of epigenetic signals and premature vascular disease; (4) epigenetic control of lipid metabolism, vascular oxidative stress, inflammation, autophagy, and apoptosis; (5) epigenetic biomarkers in patients with atherosclerosis; (6) novel therapeutic strategies to modulate epigenetic marks. Understanding the individual epigenetic profile may pave the way for new approaches to determine cardiovascular risk and to develop personalized therapies to treat atherosclerosis and its complications.

Interaction Between microRNA and DNA Methylation in Atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory disease accompanied by complex pathological changes, such as endothelial dysfunction, foam cell formation, and vascular smooth muscle cell proliferation. Many approaches, including regulating AS-related gene expression in the transcriptional or post-transcriptional level, contribute to alleviating AS development. The DNA methylation is a crucial epigenetic modification in regulating cell function by silencing the relative gene expression. The microRNA (miRNA) is a type of noncoding RNA that plays an important role in gene post-transcriptional regulation and disease development. The DNA methylation and the miRNA are important epigenetic factors in AS. However, recent studies have found a mutual regulation between these two factors in AS development. In this study, recent insights into the roles of miRNA and DNA methylation and their interaction in the AS progression are reviewed.

Disentangling the epigenetic landscape in cardiovascular patients: a path toward personalized medicine

Despite significant advances in our understanding of cardiovascular disease (CVD) we are still far from having developed breakthrough strategies to combat coronary atherosclerosis and heart failure, which account for most of CV deaths worldwide. Available cardiovascular therapies have failed to show to be equally effective in all patients, suggesting that inter-individual diversity is an important factor when it comes to conceive and deliver effective personalized treatments. Genome mapping has proved useful in identifying patients who could benefit more from specific drugs depending on genetic variances; however, our genetic make-up determines only a limited part of an individual's risk profile. Recent studies have demonstrated that epigenetic changes - defined as dynamic changes of DNA and histones which do not affect DNA sequence - are key players in the pathophysiology of cardiovascular disease and may participate to delineate cardiovascular risk trajectories over the lifetime. Epigenetic modifications include changes in DNA methylation, histone modifications and non-coding RNAs and these epigenetic signals have shown to cooperate in modulating chromatin accessibility to transcription factors and gene expression. Environmental factors such as air pollution, smoking, psychosocial context, and unhealthy diet regimens have shown to significantly modify the epigenome thus leading to altered transcriptional programs and CVD phenotypes. Therefore, the integration of genetic and epigenetic information might be invaluable to build individual maps of cardiovascular risk and hence, could be employed for the design of customized diagnostic and therapeutic strategies. In the present review, we discuss the growing importance of epigenetic information and its putative implications in cardiovascular precision medicine.

Obesity-induced activation of JunD promotes myocardial lipid accumulation and metabolic cardiomyopathy

AIMS

Metabolic cardiomyopathy (MC)-characterized by intra-myocardial triglyceride (TG) accumulation and lipotoxic damage-is an emerging cause of heart failure in obese patients. Yet, its mechanisms remain poorly understood. The Activator Protein 1 (AP-1) member JunD was recently identified as a key modulator of hepatic lipid metabolism in obese mice. The present study investigates the role of JunD in obesity-induced MC.

METHODS AND RESULTS

JunD transcriptional activity was increased in hearts from diet-induced obese (DIO) mice and was associated with myocardial TG accumulation and left ventricular (LV) dysfunction. Obese mice lacking JunD were protected against MC. In DIO hearts, JunD directly binds PPARγ promoter thus enabling transcription of genes involved in TG synthesis, uptake, hydrolysis, and storage (i.e. Fas, Cd36, Lpl, Plin5). Cardiac-specific overexpression of JunD in lean mice led to PPARγ activation, cardiac steatosis, and dysfunction, thereby mimicking the MC phenotype. In DIO hearts as well as in neonatal rat ventricular myocytes exposed to palmitic acid, Ago2 immunoprecipitation, and luciferase assays revealed JunD as a direct target of miR-494-3p. Indeed, miR-494-3p was down-regulated in hearts from obese mice, while its overexpression prevented lipotoxic damage by suppressing JunD/PPARγ signalling. JunD and miR-494-3p were also dysregulated in myocardial specimens from obese patients as compared with non-obese controls, and correlated with myocardial TG content, expression of PPARγ-dependent genes, and echocardiographic indices of LV dysfunction.

CONCLUSION

miR-494-3p/JunD is a novel molecular axis involved in obesity-related MC. These results pave the way for approaches to prevent or treat LV dysfunction in obese patients.

Precision medicine in distinct heart failure phenotypes: Focus on clinical epigenetics

Heart failure (HF) management is challenging due to high clinical heterogeneity of this disease which makes patients responding differently to evidence-based standard therapy established by the current reductionist approach. Better understanding of the genetic and epigenetic interactions may clarify molecular signatures underlying maladaptive responses in HF, including metabolic shift, myocardial injury, fibrosis, and mitochondrial dysfunction. DNA methylation, histone modifications and micro-RNA (miRNAs) may be major epigenetic players in the pathogenesis of HF. DNA hypermethylation of the kruppel-like factor 15 (KLF15) gene plays a key role in switching the failing heart from oxidative to glycolytic metabolism. Moreover, hypomethylation at H3K9 promoter level of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) genes also leads to reactivation of fetal genes in man. The role of miRNAs has been investigated in HF patients undergoing heart transplantation, for whom miR-10a, miR-155, miR-31, and miR-92 may be putative useful prognostic biomarkers. Recently, higher RNA methylation levels have been observed in ischemic human hearts, opening the era of "epitranscriptome" in the pathogenesis of HF. Currently, hydralazine, statins, apabetalone, and omega-3 polyunsatured fatty acids (PUFA) are being tested in clinical trials to provide epigenetic-driven therapeutic interventions. Moreover, network-oriented analysis could advance current medical practice by focusing on protein-protein interactions (PPIs) perturbing the "cardiac" interactome. In this review, we provide an epigenetic map of maladaptive responses in HF patients. Furthermore, we propose the "EPi-transgeneratIonal network mOdeling for STratificatiOn of heaRt Morbidity" (EPIKO-STORM), a clinical research strategy offering novel opportunities to stratify the natural history of HF.

When Good Guys Turn Bad: Bone Marrow's and Hematopoietic Stem Cells' Role in the Pathobiology of Diabetic Complications

Diabetes strongly contributes to the development of cardiovascular disease, the leading cause of mortality and morbidity in these patients. It is widely accepted that hyperglycemia impairs hematopoietic stem/progenitor cell (HSPC) mobilization from the bone marrow (BM) by inducing stem cell niche dysfunction. Moreover, a recent study demonstrated that type 2 diabetic patients are characterized by significant depletion of circulating provascular progenitor cells and increased frequency of inflammatory cells. This unbalance, potentially responsible for the reduction of intrinsic vascular homeostatic capacity and for the establishment of a low-grade inflammatory status, suggests that bone BM-derived HSPCs are not only victims but also active perpetrators in diabetic complications. In this review, we will discuss the most recent literature on the molecular mechanisms underpinning hyperglycemia-mediated BM dysfunction and differentiation abnormality of HSPCs. Moreover, a section will be dedicated to the new glucose-lowering therapies that by specifically targeting the culprits may prevent or treat diabetic complications.

The vascular epigenome in patients with obesity and type 2 diabetes: opportunities for personalized therapies

Our genetic background provides limited information on individual risk of developing vascular complications overtime. New biological layers, namely epigenetic modifications, are now emerging as potent regulators of gene expression thus leading to altered transcriptional programs and vascular disease phenotypes. Such epigenetic modifications, defined as changes to the genome that do not involve changes in DNA sequence, are generally induced by environmental factors and poor lifestyle habits. Of note, adverse epigenetic signals acquired during life can be transmitted to the offspring thus leading to premature alterations of the epigenetic and transcriptional landscape eventually leading to early endothelial dysfunction and vascular senescence. Modifications of the epigenome play a pivotal role in the pathophysiology of cardiometabolic disturbances such as obesity and type 2 diabetes. In these patients, changes of DNA methylation and chromatin structure contribute to alter pathways regulating insulin sensitivity, glucose homeostasis, adipogenesis and vascular function. In this perspective, unveiling the 'epigenetic landscape' in cardiometabolic patients may help to identify new players implicated in obesity and diabetes-related vascular dysfunction and may pave the way for personalized therapies in this setting. In the present review, we discuss current knowledge of the epigenetic routes implicated in vascular damage and cardiovascular disease in patients with metabolic alterations.

JMJD1A Represses the Development of Cardiomyocyte Hypertrophy by Regulating the Expression of Catalase

The histone demethylase JMJD family is involved in various physiological and pathological functions. However, the roles of JMJD1A in the cardiovascular system remain unknown. Here, we studied the function of JMJD1A in cardiac hypertrophy. The mRNA and protein levels of JMJD1A were significantly downregulated in the hearts of human patients with hypertrophic cardiomyopathy and the hearts of C57BL/6 mice underwent cardiac hypertrophy induced by transverse aortic constriction (TAC) surgery or isoproterenol (ISO) infusion. In neonatal rat cardiomyocytes (NRCMs), siRNA-mediated JMJD1A knockdown facilitated ISO or angiotensin II-induced increase in cardiomyocyte size, protein synthesis, and expression of hypertrophic fetal genes, including atrial natriuretic peptide (Anp), brain natriuretic peptide (Bnp), and Myh7. By contrast, overexpression of JMJD1A with adenovirus repressed the development of ISO-induced cardiomyocyte hypertrophy. We observed that JMJD1A reduced the production of total cellular and mitochondrial levels of reactive oxygen species (ROS), which was critically involved in the effects of JMJD1A because either N-acetylcysteine or MitoTEMPO treatment blocked the effects of JMJD1A deficiency on cardiomyocyte hypertrophy. Mechanism study demonstrated that JMJD1A promoted the expression and activity of Catalase under basal condition or oxidative stress. siRNA-mediated loss of Catalase blocked the protection of JMJD1A overexpression against ISO-induced cardiomyocyte hypertrophy. These findings demonstrated that JMJD1A loss promoted cardiomyocyte hypertrophy in a Catalase and ROS-dependent manner.

Apabetalone - BET protein inhibition in cardiovascular disease and Type 2 diabetes

Apabetalone is the first selective BET protein inhibitor in the field of cardiovascular diseases (CVD). BET proteins are epigenetic regulators that link upstream epigenetic modifications to downstream gene expression. Inhibition of BET proteins by apabetalone has been shown to modulate reverse cholesterol transport, coagulation, inflammation and vascular calcification. Furthermore, apabetalone reduces circulating markers of CVD risk and plaque vulnerability. Post-hoc pooled analyses suggest a potential reduction in risk of major adverse cardiac events (MACE) in patients with Type 2 diabetes (T2D) and stable CVD. However, the current cardiovascular outcomes trial BET-on-MACE failed to detect the assumed 30% reduction of MACE by apabetalone in patients with T2D after an acute coronary syndrome.