miRNA Dysregulation in Cardiovascular Diseases: Current Opinion and Future Perspectives

Plasma Extracellular MicroRNAs Associated With Cardiovascular Disease Risk Factors in Middle-Aged and Older Adults

BACKGROUND

Extracellular microRNAs (miRNAs) are a class of noncoding RNAs that remain stable in the extracellular milieu, where they contribute to various physiological and pathological processes by facilitating intercellular signaling. Previous studies have reported associations between miRNAs and cardiovascular diseases (CVDs); however, the plasma miRNA signatures of CVD and its risk factors have not been fully elucidated at the population level.

METHODS AND RESULTS

Plasma miRNA levels were measured in 4440 FHS (Framingham Heart Study) participants. Linear regression analyses were conducted to test the cross-sectional associations of each miRNA with 8 CVD risk factors. Prospective analyses of the associations of miRNAs with new-onset obesity, hypertension, type 2 diabetes, CVD, and all-cause mortality were conducted using proportional hazards regression. Replication was carried out in 1999 RS (Rotterdam Study) participants. Pathway enrichment analyses were conducted and target genes were predicted for miRNAs associated with ≥5 risk factors in the FHS. In the FHS, 6 miRNAs (miR-193b-3p, miR-122-5p, miR-365a-3p, miR-194-5p, miR-192-5p, and miR-193a-5p) were associated with ≥5 risk factors. This miRNA signature was enriched for pathways associated with CVD and several genes annotated to these pathways were predicted targets of the identified miRNAs. Furthermore, miR-193b-3p, miR-194-5p, and miR-193a-5p were each associated with ≥2 risk factors in the RS. Prospective analysis revealed 8 miRNAs associated with all-cause mortality in the FHS.

CONCLUSIONS

These findings highlight associations between miRNAs and CVD risk factors that may provide valuable insights into the underlying pathogenesis of CVD.

Non-Coding Ribonucleic Acids as Diagnostic and Therapeutic Targets in Cardiac Fibrosis

PURPOSE OF REVIEW

Cardiac fibrosis is a crucial juncture following cardiac injury and a precursor for many clinical heart disease manifestations. Epigenetic modulators, particularly non-coding RNAs (ncRNAs), are gaining prominence as diagnostic and therapeutic tools.

RECENT FINDINGS

miRNAs are short linear RNA molecules involved in post-transcriptional regulation; lncRNAs and circRNAs are RNA sequences greater than 200 nucleotides that also play roles in regulating gene expression through a variety of mechanisms including miRNA sponging, direct interaction with mRNA, providing protein scaffolding, and encoding their own products. NcRNAs have the capacity to regulate one another and form sophisticated regulatory networks. The individual roles and disease relevance of miRNAs, lncRNAs, and circRNAs to cardiac fibrosis have been increasingly well described, though the complexity of their interrelationships, regulatory dynamics, and context-specific roles needs further elucidation. This review provides an overview of select ncRNAs relevant in cardiac fibrosis as a surrogate for many cardiac disease states with a focus on crosstalk and regulatory networks, variable actions among different disease states, and the clinical implications thereof. Further, the clinical feasibility of diagnostic and therapeutic applications as well as the strategies underway to advance ncRNA theranostics is explored.

Congenital heart diseases (CHDs) and forensic investigations: Searching for the cause of death

Congenital Heart Diseases (CHDs) are a group of structural abnormalities or defects of the heart that are present at birth. CHDs could be connected to sudden death (SD), defined by the WHO (World Health Organization) as "death occurring within 24 h after the onset of the symptoms" in an apparently "healthy" subject. These conditions can range from relatively mild defects to severe, life-threatening anomalies. The prevalence of CHDs varies across populations, but they affect millions of individuals worldwide. This article aims to discuss the post-mortem investigation of death related to CHDs, exploring the forensic approach, current methodologies, challenges, and potential advancements in this challenging field. A further goal of this article is to provide a guide for understanding these complex diseases, highlighting the pivotal role of autopsy, histopathology, and genetic investigations in defining the cause of death, and providing evidence about the translational use of autopsy reports. Forensic investigations play a crucial role in understanding the complexities of CHDs and determining the cause of death accurately. Through collaboration between medical professionals and forensic experts, meticulous examinations, and analysis of evidence, valuable insights can be gained. These insights not only provide closure to the families affected but also contribute to the prevention of future tragedies.

Unraveling the Etiology of Dilated Cardiomyopathy through Differential miRNA-mRNA Interactome

Dilated cardiomyopathy (DCM) encompasses various acquired or genetic diseases sharing a common phenotype. The understanding of pathogenetic mechanisms and the determination of the functional effects of each etiology may allow for tailoring different therapeutic strategies. MicroRNAs (miRNAs) have emerged as key regulators in cardiovascular diseases, including DCM. However, their specific roles in different DCM etiologies remain elusive. Here, we applied mRNA-seq and miRNA-seq to identify the gene and miRNA signature from myocardial biopsies from four patients with DCM caused by volume overload (VCM) and four with ischemic DCM (ICM). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were used for differentially expressed genes (DEGs). The miRNA-mRNA interactions were identified by Pearson correlation analysis and miRNA target-prediction programs. mRNA-seq and miRNA-seq were validated by qRT-PCR and miRNA-mRNA interactions were validated by luciferase assays. We found 112 mRNAs and five miRNAs dysregulated in VCM vs. ICM. DEGs were positively enriched for pathways related to the extracellular matrix (ECM), mitochondrial respiration, cardiac muscle contraction, and fatty acid metabolism in VCM vs. ICM and negatively enriched for immune-response-related pathways, JAK-STAT, and NF-kappa B signaling. We identified four pairs of negatively correlated miRNA-mRNA: miR-218-5p-DDX6, miR-218-5p-TTC39C, miR-218-5p-SEMA4A, and miR-494-3p-SGMS2. Our study revealed novel miRNA-mRNA interaction networks and signaling pathways for VCM and ICM, providing novel insights into the development of these DCM etiologies.

Hydrogel-based cardiac repair and regeneration function in the treatment of myocardial infarction

A life-threatening illness that poses a serious threat to human health is myocardial infarction. It may result in a significant number of myocardial cells dying, dilated left ventricles, dysfunctional heart function, and ultimately cardiac failure. Based on the development of emerging biomaterials and the lack of clinical treatment methods and cardiac donors for myocardial infarction, hydrogels with good compatibility have been gradually applied to the treatment of myocardial infarction. Specifically, based on the three processes of pathophysiology of myocardial infarction, we summarized various types of hydrogels designed for myocardial tissue engineering in recent years, including natural hydrogels, intelligent hydrogels, growth factors, stem cells, and microRNA-loaded hydrogels. In addition, we also describe the heart patch and preparation techniques that promote the repair of MI heart function. Although most of these hydrogels are still in the preclinical research stage and lack of clinical trials, they have great potential for further application in the future. It is expected that this review will improve our knowledge of and offer fresh approaches to treating myocardial infarction.

Circulating miRNA-21 is an innovative biomarker for cardiovascular events in erectile dysfunction patients

Introduction

It is well-known that circulating microRNAs (miRNAs) play a relevant role in many kinds of diseases by regulating the expression of genes involved in various pathophysiologic processes, including erectile dysfunction (ED) and cardiovascular diseases (CVD).

Purpose

This study aimed to identify the miRNA-21 profile in the blood samples of patients with ED, CVD, and the combination of both pathologies to elucidate the potential function of miRNA-21.

Methods

A total of 45 patients with CVD and/or who underwent the erectile function test were included and divided into the following categories: CVD with ED (cases, n = 29) and controls (n = 16) with either ED or CVD. Real-time polymerase chain reaction analysis verified the results. miRNA-21 expression was quantified, and informatics analysis was applied to predict the functions of this differentially expressed miRNA-21.

Results

A total of 64% of cases (63 ± 9 years, 66% with severe ED, 56% with CV ejection fraction) first presented ED as the sentinel clinical manifestation. Serum miRNA-21 levels in the control ED were significant, up to 10-fold higher than in the CVD controls and cases. A significant inverse (p = 0.0368, β = -2.046) correlation was found between erectile function and miRNA-21 levels.

Conclusions

Our study provides comprehensive insights into the functional interaction between miRNA-21 and ED in CVD patients. Its relevance lies in the potential of miRNA as a biomarker to be applied in the cardiovascular predictive medicine field.

Forensic significance of intracardiac expressions of Nrf2 in acute myocardial ischemia

When exposed to oxidative and electrophilic stress, a protective antioxidant response is initiated by nuclear factor erythroid 2-related factor 2 (Nrf2). However, the extent of its importance in the forensic diagnosis of acute ischemic heart diseases (AIHD), such as myocardial infarction (MI), remains uncertain. On the other hand, immunohistochemical analyses of fibronectin (FN) and the terminal complement complex (C5b-9) prove valuable in identifying myocardial ischemia that precedes necrosis during the postmortem diagnosis of sudden cardiac death (SCD). In this study, we investigated the immunohistochemical levels of Nrf2, FN, and C5b-9 in human cardiac samples to explore their forensic relevance for the identification of acute cardiac ischemia. Heart samples were obtained from 25 AIHD cases and 39 non-AIHD cases as controls. Nrf2 was localized in the nuclei of cardiomyocytes, while FN and C5b-9 were detected in the myocardial cytoplasm. The number of intranuclear Nrf2 positive signals in cardiomyocytes increased in AIHD cases compared to control cases. Additionally, the grading of positive portions of cardiac FN and C5b-9 in the myocardium was also significantly enhanced in AIHD, compared to controls. Collectively, these results indicate that the immunohistochemical investigation of Nrf2 combined with FN, and/or C5b-9 holds the potential for identifying early-stage myocardial ischemic lesions in cases of SCD.

The mysterious anelloviruses: investigating its role in human diseases

Anelloviruses (AVs) that infect the human population are members of the Anelloviridae family. They are widely distributed in human populations worldwide. Torque teno virus (TTV) was the first virus of this family to be identified and is estimated to be found in the serum of 80-90% of the human population. Sometime after the identification of TTV, Torque teno mini virus (TTMV) and Torque teno midi virus (TTMDV) were also identified and classified in this family. Since identifying these viruses, have been detected in various types of biological fluids of the human body, including blood and urine, as well as vital organs such as the liver and kidney. They can be transmitted from person to person through blood transfusions, fecal-oral contact, and possibly sexual intercourse. Recent studies on these newly introduced viruses show that although they are not directly related to human disease, they may be indirectly involved in initiating or exacerbating some human population-related diseases and viral infections. Among these diseases, we can mention various types of cancers, immune system diseases, viral infections, hepatitis, and AIDS. Also, they likely use the microRNAs (miRNAs) they encode to fulfill this cooperative role. Also, in recent years, the role of proliferation and their viral load, especially TTV, has been highlighted to indicate the immune system status of immunocompromised people or people who undergo organ transplants. Here, we review the possible role of these viruses in diseases that target humans and highlight them as important viruses that require further study. This review can provide new insights to researchers.

Crosstalk of NLRP3 inflammasome and noncoding RNAs in cardiomyopathies

Cardiovascular diseases (CVDs) identified as a serious public health problem. Although there is a lot of evidence that inflammatory processes play a significant role in the progression of CVDs, however, the precise mechanism is not fully understood. Nevertheless, recent studies have focused on inflammation and its related agents. Nucleotide oligomerization domain-, leucine-rich repeat-, and pyrin domain-containing protein 3 (NLRP3) is a type of pattern recognition receptor (PRR) that can recognize pathogen-associated molecular patterns and trigger innate immune response. NLRP3 is a component of the NOD-like receptor (NLR) family and have a pivotal role in detecting damage to cardiovascular tissue. It is suggested that activation of NLRP3 inflammasome leads to initiating and propagating the inflammatory response in cardiomyopathy. So, late investigations have highlighted the NLRP3 inflammasome activation in various forms of cardiomyopathy. On the other side, it was shown that noncoding RNAs (ncRNAs), particularly, microRNAs, lncRNAs, and circRNAs possess a regulatory function in the immune system's inflammatory response, implicating their involvement in various inflammatory disorders. In addition, their role in different cardiomyopathies was indicated in recent studies. This review article provides a summary of recent advancements focusing on the function of the NLRP3 inflammasome in common CVDs, especially cardiomyopathy, while also discussing the therapeutic potential of inhibiting the NLRP3 inflammasome regulated by ncRNAs.

Plasma microrna quantification protocol

MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate translation and are involved in many pathological processes. They have emerged as promising biomarkers for diagnosis of conditions such as aortic aneurysm disease. Quantifying miRNAs in plasma is uniquely challenging because of the lack of standardized reproducible protocols. To facilitate the independent verification of conclusions, it is necessary to provide a thorough disclosure of all pertinent experimental details. In this technical note, we present a comprehensive protocol for quantifying plasma miRNAs using droplet digital PCR. We detail the entire workflow, including blood collection, plasma processing, cryo-storage, miRNA isolation, reverse transcription, droplet generation, PCR amplification, fluorescence reading, and data analysis. We offer comprehensive guidance regarding optimization, assay conditions, expected results, and insight into the troubleshooting of common issues. The stepwise normalization and detailed methodological guide enhance reproducibility. Moreover, multiple portions of this protocol may be automated. The data provided in this technical note is demonstrative of the values typically obtained when following its steps. To facilitate standardization in data reporting, we include a table of expected aortic aneurysm-related miRNA levels in healthy human plasma. This versatile protocol can be easily adapted to quantify most circulating miRNAs in plasma, making it a valuable resource for diagnostic development.

MicroRNAs: Midfielders of Cardiac Health, Disease and Treatment

MicroRNAs (miRNAs) are a class of small non-coding RNA molecules that play a role in post-transcriptional gene regulation. It is generally accepted that their main mechanism of action is the negative regulation of gene expression, through binding to specific regions in messenger RNA (mRNA) and repressing protein translation. By interrupting protein synthesis, miRNAs can effectively turn genes off and influence many basic processes in the body, such as developmental and apoptotic behaviours of cells and cardiac organogenesis. Their importance is highlighted by inhibiting or overexpressing certain miRNAs, which will be discussed in the context of coronary artery disease, atrial fibrillation, bradycardia, and heart failure. Dysregulated levels of miRNAs in the body can exacerbate or alleviate existing disease, and their omnipresence in the body makes them reliable as quantifiable markers of disease. This review aims to provide a summary of miRNAs as biomarkers and their interactions with targets that affect cardiac health, and intersperse it with current therapeutic knowledge. It intends to succinctly inform on these topics and guide readers toward more comprehensive works if they wish to explore further through a wide-ranging citation list.

The potential role of miRNAs in the pathogenesis of cardiovascular diseases - A focus on signaling pathways interplay

For the past two decades since their discovery, scientists have linked microRNAs (miRNAs) to posttranscriptional regulation of gene expression in critical cardiac physiological and pathological processes. Multiple non-coding RNA species regulate cardiac muscle phenotypes to stabilize cardiac homeostasis. Different cardiac pathological conditions, including arrhythmia, myocardial infarction, and hypertrophy, are modulated by non-coding RNAs in response to stress or other pathological conditions. Besides, miRNAs are implicated in several modulatory signaling pathways of cardiovascular disorders including mitogen-activated protein kinase, nuclear factor kappa beta, protein kinase B (AKT), NOD-like receptor family pyrin domain-containing 3 (NLRP3), Jun N-terminal kinases (JNKs), Toll-like receptors (TLRs) and apoptotic protease-activating factor 1 (Apaf-1)/caspases. This review highlights the potential role of miRNAs as therapeutic targets and updates our understanding of their roles in the processes underlying pathogenic phenotypes of cardiac muscle.

New Insight into Mechanisms of Cardiovascular Diseases: An Integrative Analysis Approach to Identify TheranoMiRNAs

MiRNAs regulate both physiological and pathological heart functions. Altered expression of miRNAs is associated with cardiovascular diseases (CVDs), making miRNAs attractive therapeutic strategies for the diagnosis and treatment of heart diseases. A recent publication defined, for the first time, the term theranoMiRNA, meaning the miRNAs that may be used both for diagnosis and treatment. The use of in silico tools may be considered fundamental for these purposes, clarifying several molecular aspects, suggesting future directions for in vivo studies. This study aims to explore different bioinformatic tools in order to clarify miRNA interactions with candidate genes, demonstrating the need to use a computational approach when establishing the most probable associations between miRNAs and target genes. This study focused on the functions of miR-133a-3p, miR-21-5p, miR-499a-5p, miR-1-3p, and miR-126-3p, providing an up-to-date overview, and suggests future lines of research in the identification of theranoMiRNAs related to CVDs. Based on the results of the present study, we elucidated the molecular mechanisms that could be linked between miRNAs and CVDs, confirming that these miRNAs play an active role in the genesis and development of heart damage. Given that CVDs are the leading cause of death in the world, the identification of theranoMiRNAs is crucial, hence the need for a definition of in vivo studies in order to obtain further evidence in this challenging field of research.