Epigenetic Biomarkers and Cardiovascular Disease: Circulating MicroRNAs

A 2-decade bibliometric analysis of epigenetics of cardiovascular disease: from past to present

BACKGROUND

Cardiovascular disease (CVD) remains a major health killer worldwide, and the role of epigenetic regulation in CVD has been widely studied in recent decades. Herein, we perform a bibliometric study to decipher how research topics in this field have evolved during the past 2 decades.

RESULTS

Publications on epigenetics in CVD produced during the period 2000-2022 were retrieved from the Web of Science Core Collection (WoSCC). We utilized Bibliometrix to build a science map of the publications and applied VOSviewer and CiteSpace to assess co-authorship, co-citation, co-occurrence, and bibliographic coupling. In total, 27,762 publications were included for bibliometric analysis. The yearly amount of publications experienced exponential growth. The top 3 most influential countries were China, the United States, and Germany, while the most cited institutions were Nanjing Medical University, Harbin Medical University, and Shanghai Jiao Tong University. Four major research trends were identified: (a) epigenetic mechanisms of CVD; (b) epigenetics-based therapies for CVD; (c) epigenetic profiles of specific CVDs; and (d) epigenetic biomarkers for CVD diagnosis/prediction. The latest and most important research topics, including "nlrp3 inflammasome", "myocardial injury", and "reperfusion injury", were determined by detecting citation bursts of co-occurring keywords. The most cited reference was a review of the current knowledge about how miRNAs recognize target genes and modulate their expression and function.

CONCLUSIONS

The number and impact of global publications on epigenetics in CVD have expanded rapidly over time. Our findings may provide insights into the epigenetic basis of CVD pathogenesis, diagnosis, and treatment.

Cytokines and microRNAs in SARS-CoV-2: What do we know?

The coronavirus disease 2019 (COVID-19) pandemic constitutes a global health emergency. Currently, there are no completely effective therapeutic medications for the management of this outbreak. The cytokine storm is a hyperinflammatory medical condition due to excessive and uncontrolled release of pro-inflammatory cytokines in patients suffering from severe COVID-19, leading to the development of acute respiratory distress syndrome (ARDS) and multiple organ dysfunction syndrome (MODS) and even mortality. Understanding the pathophysiology of COVID-19 can be helpful for the treatment of patients. Evidence suggests that the levels of tumor necrosis factor alpha (TNF-α) and interleukin (IL)-1 and IL-6 are dramatically different between mild and severe patients, so they may be important contributors to the cytokine storm. Several serum markers can be predictors for the cytokine storm. This review discusses the cytokines involved in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, focusing on interferons (IFNs) and ILs, and whether they can be used in COVID-19 treatment. Moreover, we highlight several microRNAs that are involved in these cytokines and their role in the cytokine storm caused by COVID-19.

The Genetic Architecture of the Etiology of Lower Extremity Peripheral Artery Disease: Current Knowledge and Future Challenges in the Era of Genomic Medicine

Lower extremity artery disease (LEAD), caused by atherosclerotic obstruction of the arteries of the lower limb extremities, has exhibited an increase in mortality and morbidity worldwide. The phenotypic variability of LEAD is correlated with its complex, multifactorial etiology. In addition to traditional risk factors, it has been shown that the interaction between genetic factors (epistasis) or between genes and the environment potentially have an independent role in the development and progression of LEAD. In recent years, progress has been made in identifying genetic variants associated with LEAD, by Genome-Wide Association Studies (GWAS), Whole Exome Sequencing (WES) studies, and epigenetic profiling. The aim of this review is to present the current knowledge about the genetic factors involved in the etiopathogenic mechanisms of LEAD, as well as possible directions for future research. We analyzed data from the literature, starting with candidate gene-based association studies, and then continuing with extensive association studies, such as GWAS and WES. The results of these studies showed that the genetic architecture of LEAD is extremely heterogeneous. In the future, the identification of new genetic factors will allow for the development of targeted molecular therapies, and the use of polygenic risk scores (PRS) to identify individuals at an increased risk of LEAD will allow for early prophylactic measures and personalized therapy to improve their prognosis.

MicroRNA as a Novel Biomarker in the Diagnosis of Head and Neck Cancer

Head and neck squamous cell carcinoma is the sixth most common cancer worldwide, with 890,000 new cases and 450,000 deaths in 2018, and although the survival statistics for some patient groups are improving, there is still an urgent need to find a fast and reliable biomarker that allows early diagnosis. This niche can be filled by microRNA, small single-stranded non-coding RNA molecules, which are expressed in response to specific events in the body. This article presents the potential use of microRNAs in the diagnosis of HNSCC, compares the advances in this field to other diseases, especially other cancers, and discusses the detailed use of miRNA as a biomarker in profiling and predicting the treatment outcome with radiotherapy and immunotherapy. Potential problems and difficulties related to the development of this promising technology, and areas on which future research should be focused in order to overcome these difficulties, were also indicated.

Genetics of Cardiovascular Disease: How Far Are We from Personalized CVD Risk Prediction and Management?

Despite the rapid progress in diagnosis and treatment of cardiovascular disease (CVD), this disease remains a major cause of mortality and morbidity. Recent progress over the last two decades in the field of molecular genetics, especially with new tools such as genome-wide association studies, has helped to identify new genes and their variants, which can be used for calculations of risk, prediction of treatment efficacy, or detection of subjects prone to drug side effects. Although the use of genetic risk scores further improves CVD prediction, the significance is not unambiguous, and some subjects at risk remain undetected. Further research directions should focus on the "second level" of genetic information, namely, regulatory molecules (miRNAs) and epigenetic changes, predominantly DNA methylation and gene-environment interactions.

Epigenetic regulation by polyphenols in diabetes and related complications

Diabetes mellitus (DM) is a chronic metabolic disorder and one of the most challenging health problems worldwide. Left untreated, it may progress causing serious complications. Genetics, epigenetics, and environmental factors are known to play an overlapping role in the pathogenesis of DM. Growing evidence suggests the hypothesis that the environment induces changes in the early phases of growth and development, influencing health and disease in the adulthood through the alteration in genetic expression of an individual, at least in part. DNA methylation, histone modifications and miRNAs are three mechanisms responsible for epigenetic alterations. The daily diet contains a number of secondary metabolites, with polyphenols being highest in abundance, which contribute to overall health and may prevent or delay the onset of many chronic diseases. Polyphenols have the ability to alter metabolic and signaling pathways at various levels, such as gene expression, epigenetic regulation, protein expression and enzyme activity. The potential efficacy of polyphenolic compounds on glucose homeostasis has been evidenced from in vitro, in vivo and clinical studies. The present review is designed to focus on epigenetic regulation exerted by polyphenolic compounds in DM and their complications, as well as to summarize clinical trials involving polyphenols in DM.

Morphine leads to global genome changes in H3K27me3 levels via a Polycomb Repressive Complex 2 (PRC2) self-regulatory mechanism in mESCs

Background

Environmentally induced epigenetic changes can lead to health problems or disease, but the mechanisms involved remain unclear. Morphine can pass through the placental barrier leading to abnormal embryo development. However, the mechanism by which morphine causes these effects and how they sometimes persist into adulthood is not well known. To unravel the morphine-induced chromatin alterations involved in aberrant embryo development, we explored the role of the H3K27me3/PRC2 repressive complex in gene expression and its transmission across cellular generations in response to morphine.

Results

Using mouse embryonic stem cells as a model system, we found that chronic morphine treatment induces a global downregulation of the histone modification H3K27me3. Conversely, ChIP-Seq showed a remarkable increase in H3K27me3 levels at specific genomic sites, particularly promoters, disrupting selective target genes related to embryo development, cell cycle and metabolism. Through a self-regulatory mechanism, morphine downregulated the transcription of PRC2 components responsible for H3K27me3 by enriching high H3K27me3 levels at the promoter region. Downregulation of PRC2 components persisted for at least 48 h (4 cell cycles) following morphine removal, though promoter H3K27me3 levels returned to control levels.

Conclusions

Morphine induces targeting of the PRC2 complex to selected promoters, including those of PRC2 components, leading to characteristic changes in gene expression and a global reduction in H3K27me3. Following morphine removal, enhanced promoter H3K27me3 levels revert to normal sooner than global H3K27me3 or PRC2 component transcript levels. We suggest that H3K27me3 is involved in initiating morphine-induced changes in gene expression, but not in their maintenance.

Graphic abstract

Model of Polycomb repressive complex 2 (PRC2) and H3K27me3 alterations induced by chronic morphine exposure. Morphine induces H3K27me3 enrichment at promoters of genes encoding core members of the PRC2 complex and is associated with their transcriptional downregulation.

The Role of MicroRNAs in Regulating Cytokines and Growth Factors in Coronary Artery Disease: The Ins and Outs

Coronary artery diseases (CAD), as a leading cause of mortality around the world, has attracted the researchers' attention for years to find out its underlying mechanisms and causes. Among the various key players in the pathogenesis of CAD cytokines, microRNAs (miRNAs) are crucial. In this study, besides providing a comprehensive overview of the involvement of cytokines, growth factors, and miRNAs in CAD, the interplay between miRNA with cytokine or growth factors during the development of CAD is discussed.

Circulating Levels of Brain-Enriched MicroRNAs Correlate with Neuron Specific Enolase after Cardiac Arrest-A Substudy of the Target Temperature Management Trial

Outcome prognostication after cardiac arrest (CA) is challenging. Current multimodal prediction approaches would benefit from new biomarkers. MicroRNAs constitute a novel class of disease markers and circulating levels of brain-enriched ones have been associated with outcome after CA. To determine whether these levels reflect the extent of brain damage in CA patients, we assessed their correlation with neuron-specific enolase (NSE), a marker of brain damage. Blood samples taken 48 h after return of spontaneous circulation from two groups of patients from the Targeted Temperature Management trial were used. Patients were grouped depending on their neurological outcome at six months. Circulating levels of microRNAs were assessed by sequencing. NSE was measured at the same time-point. Among the 673 microRNAs detected, brain-enriched miR9-3p, miR124-3p and miR129-5p positively correlated with NSE levels (all p < 0.001). Interestingly, these correlations were absent when only the good outcome group was analyzed (p > 0.5). Moreover, these correlations were unaffected by demographic and clinical characteristics. All three microRNAs predicted neurological outcome at 6 months. Circulating levels of brain-enriched microRNAs are correlated with NSE levels and hence can reflect the extent of brain injury in patients after CA. This observation strengthens the potential of brain-enriched microRNAs to aid in outcome prognostication after CA.

MicroRNAs as Biomarkers and Therapeutic Targets in Heart Failure

Heart failure still represents a real challenge both in everyday practice and research, due to the complex issues related to its pathogenesis and management. Humoral biomarkers have emerged in the last decades as useful tools in the diagnosis, risk stratification and guiding the treatment of heart failure. These molecules are related to different pathological and adaptive processes, like myocardial injury, neurohormonal activation and cardiac remodeling, their most widespread representatives being the natriuretic peptides (e.g. NT-proBNP). The role of altered gene expression and transcription as the basis of myocardial structural and functional changes in heart failure is largely recognized. MicroRNAs (miRNAs) are non-coding RNAs which have a major role in post-transcriptional gene expression by interfering with messenger RNA molecules. Our short review summarizes the molecular biology of miRNAs and their possible role as biomarkers in the diagnosis and prognosis of heart failure. Furthermore, the therapeutical perspectives conferred by these molecules are also presented.

Plasma microRNA Profiling Reveals Novel Biomarkers of Epicardial Adipose Tissue: A Multidetector Computed Tomography Study

Epicardial adipose tissue (EAT) constitutes a novel parameter for cardiometabolic risk assessment and a target for therapy. Here, we evaluated for the first time the plasma microRNA (miRNA) profile as a source of biomarkers for epicardial fat volume (EFV). miRNAs were profiled in plasma samples from 180 patients whose EFV was quantified using multidetector computed tomography. In the screening study, 54 deregulated miRNAs were identified in patients with high EFV levels (highest tertile) compared with matched patients with low EFV levels (lowest tertile). After filtering, 12 miRNAs were selected for subsequent validation. In the validation study, miR-15b-3p, miR-22-3p, miR-148a-3p miR-148b-3p and miR-590-5p were directly associated with EFV, even after adjustment for confounding factors (p value < 0.05 for all models). The addition of miRNA combinations to a model based on clinical variables improved the discrimination (area under the receiver-operating-characteristic curve (AUC) from 0.721 to 0.787). miRNAs correctly reclassified a significant proportion of patients with an integrated discrimination improvement (IDI) index of 0.101 and a net reclassification improvement (NRI) index of 0.650. Decision tree models used miRNA combinations to improve their classification accuracy. These results were reproduced using two proposed clinical cutoffs for epicardial fat burden. Internal validation corroborated the robustness of the models. In conclusion, plasma miRNAs constitute novel biomarkers of epicardial fat burden.