Increased microRNA-1 and microRNA-133a levels in serum of patients with cardiovascular disease indicate myocardial damage

Treatment of Oxidative Stress with Exosomes in Myocardial Ischemia

A thrombus in a coronary artery causes ischemia, which eventually leads to myocardial infarction (MI) if not removed. However, removal generates reactive oxygen species (ROS), which causes ischemia–reperfusion (I/R) injury that damages the tissue and exacerbates the resulting MI. The mechanism of I/R injury is currently extensively understood. However, supplementation of exogenous antioxidants is ineffective against oxidative stress (OS). Enhancing the ability of endogenous antioxidants may be a more effective way to treat OS, and exosomes may play a role as targeted carriers. Exosomes are nanosized vesicles wrapped in biofilms which contain various complex RNAs and proteins. They are important intermediate carriers of intercellular communication and material exchange. In recent years, diagnosis and treatment with exosomes in cardiovascular diseases have gained considerable attention. Herein, we review the new findings of exosomes in the regulation of OS in coronary heart disease, discuss the possibility of exosomes as carriers for the targeted regulation of endogenous ROS generation, and compare the advantages of exosome therapy with those of stem-cell therapy. Finally, we explore several miRNAs found in exosomes against OS.

Systematic review of microRNA biomarkers in acute coronary syndrome and stable coronary artery disease

The aim of this systematic review was to assess dysregulated miRNA biomarkers in coronary artery disease (CAD). Dysregulated microRNA (miRNAs) have been shown to be linked to cardiovascular pathologies including CAD and may have utility as diagnostic and prognostic biomarkers. We compared miRNAs identified in acute coronary syndrome (ACS) compared with stable CAD and control populations. We conducted a systematic search of controlled vocabulary and free text terms related to ACS, stable CAD and miRNA in Biosis Previews (OvidSP), The Cochrane Library (Wiley), Embase (OvidSP), Global Health (OvidSP), Medline (PubMed and OvidSP), Web of Science (Clarivate Analytics), and ClinicalTrials.gov which yielded 7370 articles. Of these, 140 original articles were appropriate for data extraction. The most frequently reported miRNAs in any CAD (miR-1, miR-133a, miR-208a/b, and miR-499) are expressed abundantly in the heart and play crucial roles in cardiac physiology. In studies comparing ACS cases with stable CAD patients, miR-21, miR-208a/b, miR-133a/b, miR-30 family, miR-19, and miR-20 were most frequently reported to be dysregulated in ACS. While a number of miRNAs feature consistently across studies in their expression in both ACS and stable CAD, when compared with controls, certain miRNAs were reported as biomarkers specifically in ACS (miR-499, miR-1, miR-133a/b, and miR-208a/b) and stable CAD (miR-215, miR-487a, and miR-502). Thus, miR-21, miR-133, and miR-499 appear to have the most potential as biomarkers to differentiate the diagnosis of ACS from stable CAD, especially miR-499 which showed a correlation between the level of their concentration gradient and myocardial damage. Although these miRNAs are potential diagnostic biomarkers, these findings should be interpreted with caution as the majority of studies conducted predefined candidate-driven assessments of a limited number of miRNAs (PROSPERO registration: CRD42017079744).

miR-19a-3p containing exosomes improve function of ischaemic myocardium upon shock wave therapy

AIMS

As many current approaches for heart regeneration exert unfavourable side effects, the induction of endogenous repair mechanisms in ischaemic heart disease is of particular interest. Recently, exosomes carrying angiogenic miRNAs have been described to improve heart function. However, it remains challenging to stimulate specific release of reparative exosomes in ischaemic myocardium. In the present study, we sought to test the hypothesis that the physical stimulus of shock wave therapy (SWT) causes the release of exosomes. We aimed to substantiate the pro-angiogenic impact of the released factors, to identify the nature of their cargo, and to test their efficacy in vivo supporting regeneration and recovery after myocardial ischaemia.

METHODS AND RESULTS

Mechanical stimulation of ischaemic muscle via SWT caused extracellular vesicle (EV) release from endothelial cells both in vitro and in vivo. Characterization of EVs via electron microscopy, nanoparticle tracking analysis and flow cytometry revealed specific exosome morphology and size with the presence of exosome markers CD9, CD81, and CD63. Exosomes exhibited angiogenic properties activating protein kinase b (Akt) and extracellular-signal regulated kinase (ERK) resulting in enhanced endothelial tube formation and proliferation. A miRNA array and transcriptome analysis via next-generation sequencing were performed to specify exosome content. miR-19a-3p was identified as responsible cargo, antimir-19a-3p antagonized angiogenic exosome effects. Exosomes and target miRNA were injected intramyocardially in mice after left anterior descending artery ligation. Exosomes resulted in improved vascularization, decreased myocardial fibrosis, and increased left ventricular ejection fraction as shown by transthoracic echocardiography.

CONCLUSION

The mechanical stimulus of SWT causes release of angiogenic exosomes. miR-19a-3p is the vesicular cargo responsible for the observed effects. Released exosomes induce angiogenesis, decrease myocardial fibrosis, and improve left ventricular function after myocardial ischaemia. Exosome release via SWT could develop an innovative approach for the regeneration of ischaemic myocardium.

Secondary mitral regurgitation-Insights from microRNA assessment

BACKGROUND

While secondary mitral regurgitation (sMR) is associated with adverse outcome in heart failure with reduced ejection fraction (HFrEF), key pathophysiologic mechanisms remain poorly understood and might be elucidated by microRNAs (miRNA/miR), that were recently related to cardiac remodelling. This study sought to assess (i) the differences of miRNA profiles in patients with severe sMR compared to matched disease controls, (ii) the correlation between circulating miRNAs and surrogates of sMR severity as well as (iii) the prognostic implications of miRNA levels in severe sMR.

MATERIALS AND METHODS

Sixty-six HFrEF patients were included, of these 44 patients with severe sMR 2:1 matched to HFrEF controls with no/mild sMR. A comprehensive set of miRNAs (miR-21, miR-29a, miR-122, miR-132, miR-133a, miR-let7i) were measured and correlated to echocardiographic sMR severity.

RESULTS

miRNA patterns differed distinctly between patients with severe sMR and HFrEF controls (P < .05). Among the panel of assessed miRNAs, miR-133a correlated most strongly with surrogates of sMR severity (r = -0.41, P = .001 with sMR vena contracta width). Interestingly, elevated levels of miR-133 were associated with an increased risk for cardiovascular death and/or HF hospitalizations with and adjusted HR of 1.85 (95% CI 1.24-2.76, P = .003).

CONCLUSIONS

This study unveils distinct pathophysiologic maladaptions at a cellular level in patients with severe sMR compared to no/mild sMR by showing significant differences in miRNA profiles and correlations with sMR severity, supporting the concept that sMR drives cardiac remodelling in heart failure. Moreover, the increased risk for adverse outcome in HFrEF patients with severe sMR conveyed by miR-133a might indicate irreversible myocardial damage.

Exosome-Derived Mediators as Potential Biomarkers for Cardiovascular Diseases: A Network Approach

Cardiovascular diseases (CVDs) are widely recognized as the leading cause of mortality worldwide. Despite the advances in clinical management over the past decades, the underlying pathological mechanisms remain largely unknown. Exosomes have drawn the attention of researchers for their relevance in intercellular communication under both physiological and pathological conditions. These vesicles are suggested as complementary prospective biomarkers of CVDs; however, the role of exosomes in CVDs is still not fully elucidated. Here, we performed a literature search on exosomal biogenesis, characteristics, and functions, as well as the different available exosomal isolation techniques. Moreover, aiming to give new insights into the interaction between exosomes and CVDs, network analysis on the role of exosome-derived mediators in coronary artery disease (CAD) and heart failure (HF) was also performed to incorporate the different sources of information. The upregulated exosomal miRNAs miR-133a, miR-208a, miR-1, miR-499-5p, and miR-30a were described for the early diagnosis of acute myocardial infarction, while the exosome-derived miR-192, miR-194, miR-146a, and miR-92b-5p were considered as potential biomarkers for HF development. In CAD patients, upregulated exosomal proteins, including fibrinogen beta/gamma chain, inter-alpha-trypsin inhibitor heavy chain, and alpha-1 antichymotrypsin, were assessed as putative protein biomarkers. From downregulated proteins in CAD patients, albumin, clusterin, and vitamin D-binding protein were considered relevant to assess prognosis. The Vesiclepedia database included miR-133a of exosomal origin upregulated in patients with CAD and the exosomal miR-192, miR-194, and miR-146a upregulated in patients with HF. Additionally, Vesiclepedia included 5 upregulated and 13 downregulated exosomal proteins in patients in CAD. The non-included miRNAs and proteins have not yet been identified in exosomes and can be proposed for further research. This report highlights the need for further studies focusing on the identification and validation of miRNAs and proteins of exosomal origin as biomarkers of CAD and HF, which will enable, using exosomal biomarkers, the guiding of diagnosis/prognosis in CVDs.

The role of miRNAs in polycystic ovary syndrome with insulin resistance

PURPOSE

This review aims to summarize the key findings of several miRNAs and their roles in polycystic ovary syndrome with insulin resistance, characterize the disease pathogenesis, and establish a new theoretical basis for diagnosing, treating, and preventing polycystic ovary syndrome.

METHODS

Relevant scientific literature was covered from 1992 to 2020 by searching the PubMed database with search terms: insulin/insulin resistance, polycystic ovary syndrome, microRNAs, and metabolic diseases. References of relevant studies were cross-checked.

RESULTS

The related miRNAs (including differentially expressed miRNAs) and their roles in pathogenesis, and possible therapeutic targets and pathways, are discussed, highlighting controversies and offering thoughts for future directions.

CONCLUSION

We found abundant evidence on the role of differentially expressed miRNAs with its related phenotypes in PCOS. Considering the essential role of insulin resistance in the pathogenesis of PCOS, the alterations of associated miRNAs need more research attention. We speculate that race/ethnicity or PCOS phenotype and differences in methodological differences might lead to inconsistencies in research findings; thus, several miRNA profiles need to be investigated further to qualify for the potential therapeutic targets for PCOS-IR.

Evaluation of exosomal miRNAs as potential diagnostic biomarkers for acute myocardial infarction using next-generation sequencing

BACKGROUND

Acute myocardial infarction (AMI) is one of the most common global causes of death. Although considerable progress has been made in AMI diagnosis, there remains an urgent need for novel diagnostic biomarkers for its prevention and treatment. Functional exosomal microRNAs (miRNAs) are recognized as potential biomarkers in many diseases. This study's objective was to identify specific plasma exosomal miRNAs with biomarker potential for early AMI detection.

METHODS

Exosomes from the plasma of 26 coronary artery disease (CAD) patients, 55 AMI patients, and 37 healthy controls were isolated and characterized by transmission electron microcopy (TEM), western blotting, and nanoparticle tracking analysis (NTA). The miRNAs were purified from exosomes, and unique molecular identifier (UMI) small RNA sequencing was performed. The random forest (RF) model was trained to predict potential biomarkers.

RESULTS

NTA demonstrated that nanoparticle concentration did not change after AMI, while nanoparticle size distribution significantly decreased. The CAD and AMI groups' miRNA expression profiles significantly differed from the healthy group's profile. The RF classifier could be used to distinguish the healthy group from the AMI group, but could not be used to distinguish the CAD group from the other groups, which caused a high classification error rate. Eighteen miRNAs were selected as biomarkers based on their RF classifier significance. The diagnostic accuracy of 18 miRNAs was evaluated using AUC values of 0.93, 0.87, and 0.75 to detect healthy controls, AMI, and CAD, respectively.

CONCLUSIONS

Nanoparticle diameter and the 18 miRNAs may serve as simple and accessible fingerprints for early AMI diagnosis.

Cellular signaling cross-talk between different cardiac cell populations: an insight into the role of exosomes in the heart diseases and therapy

Exosomes are a subgroup of extracellular bilayer membrane nanovesicles that are enriched in a variety of bioactive lipids, receptors, transcription factors, surface proteins, DNA, and noncoding RNAs. They have been well recognized to play essential roles in mediating intercellular signaling by delivering bioactive molecules from host cells to regulate the physiological processes of recipient cells. In the context of heart diseases, accumulating studies have indicated that exosome-carried cellular proteins and noncoding RNA derived from different types of cardiac cells, including cardiomyocytes, fibroblasts, endothelial cells, immune cells, adipocytes, and resident stem cells, have pivotal roles in cardiac remodeling under disease conditions such as cardiac hypertrophy, diabetic cardiomyopathy, and myocardial infarction. In addition, exosomal contents derived from stem cells have been shown to be beneficial for regenerative potential of the heart. In this review, we discuss current understanding of the role of exosomes in cardiac communication, with a focus on cardiovascular pathophysiology and perspectives for their potential uses as cardiac therapies.

Difference in microRNA levels in the post-mortem blood from different sampling sites: A proof of concept

MicroRNAs have various characteristics, including stability, and tissue and disease specificity. One of the important issues in forensics is that biomarkers can differ quantitatively depending on the sampling site. We aimed at evaluating the differences in microRNA levels in the post-mortem (PM) blood from different sampling sites. The study subjects comprised seventeen males and eleven females. The number of cardiac deaths (CD) and non-cardiac deaths (NCD) was eleven and seventeen, respectively. A cardiopulmonary resuscitation (CPR) was performed in fifteen cases. Venous blood was obtained from the external iliac vein for peripheral blood (PB), inferior vena cava for pre-cardiac blood (CB), and coronary sinus for post-cardiac blood (coronary sinus blood, CSB). The selected target microRNAs were cardiac-specific (miR208 and miR-1) and non-cardiac microRNAs (miR-16 and let-7e). The levels of miR-208b and miR-1 in the PM blood differed according to its sampling site and showed an increasing order of tendency in the PB, CB, and CSB. However, these variations according to sampling sites did not correlate with the post-mortem interval and the levels did not differ between the CD and NCD groups, and between the CPR and non-CPR groups. MiR-16 and let-7e levels did not vary according to the sampling site. The present study confirms that the cardiac-specific microRNA levels in the PM blood from different sampling sites are different. In addition, this study showed that the characteristics of target microRNAs, such as tissue-specificity, should be considered and the sampling site for microRNAs should be presented in forensic applications.

Diagnostic value of circulating microRNAs compared to high-sensitivity troponin T for the detection of non-ST-segment elevation myocardial infarction

AIMS

To assess the diagnostic value of microRNAs (miRNAs) for the detection of non-ST-segment elevation myocardial infarction (NSTEMI).

METHODS AND RESULTS

A total of 1042 patients presenting between August 2014 and April 2017 to the emergency department with the suspected acute coronary syndrome were included. Non-ST-segment elevation myocardial infarction was diagnosed per criteria of the fourth Universal definition of myocardial infarction (UDMI) using high-sensitivity troponin T (hs-cTnT). Expression levels of eleven microRNAs (miR-21, miR-22, miR-29a, miR-92a, miR-122, miR-126, miR-132, miR-133, miR-134, miR-191, and miR-423) were determined using RT-qPCR. Discrimination of NSTEMI was assessed for individual and a panel of miRNAs compared to the hs-cTnT reference using C-statistics and reclassification analysis. NSTEMI was diagnosed in 137 (13.1%) patients. The area under the curve (AUC) of the hs-cTnT based reference was 0.937. In a multivariate model, three miRNAs (miR-122, miR-133, and miR-134) were found to be associated with NSTEMI with AUCs between 0.506 and 0.656. A panel consisting of these miRNAs revealed an AUC of 0.662 for the diagnosis of NSTEMI. The AUC of the combination of the miRNA panel and troponin reference was significantly lower than the reference standard (AUC: 0.897 vs. 0.937, P = 0.006). Despite a significant improvement of NSTEMI reclassification measured by IDI and NRI, miRNAs did not improve the specificity of hs-cTnT kinetic changes for the diagnosis of NSTEMI (ΔAUC: 0.04).

CONCLUSION

Although single miRNAs are significantly associated with the diagnosis of NSTEMI a miRNA panel does not add diagnostic accuracy to the hs-cTnT reference considering baseline values and kinetic changes as recommended by the fourth version of UDMI.

CLINICAL TRIALS IDENTIFIER

NCT02116153.

Circulating exosomes in cardiovascular disease: Novel carriers of biological information

Exosomes are a group of nanosized extracellular vesicles that include various bioactive nucleic acids, lipids, and proteins. They originate from membrane invagination and are released by exocytosis, which can transmit signals to target cells to achieve cell-to-cell communication and maintain homeostasis. The heart is a complex multicellular organ that contains resident cell types such as fibroblasts, endothelial cells, and smooth muscle cells. Communication between different cell types and immune systems is essential for the dynamic equilibrium of the cardiac internal environment. Intercellular communication is a universal phenomenon mediated by exosomes and their contents during several pathological processes in cardiovascular diseases, such as cardiomyocyte hypertrophy, apoptosis, and angiogenesis. Therefore, exosomes can be used as novel invasive diagnostic biomarkers in multiple diseases, including atherosclerosis, myocardial ischemia, cardiac fibrosis, and ischemia-reperfusion injury. In addition, the biocompatible nature and low immunogenicity of exosomes make them high-quality nanoparticle drug carriers with potential applications in translational medicine and therapeutic strategies. Here, we focus on the biogenesis, isolation, biological functions, and future application prospects of exosomes in cardiovascular disease.

Takotsubo Syndrome: Clinical Manifestations, Etiology and Pathogenesis

The purpose of the review is the analysis of clinical and experimental data on the etiology and pathogenesis of takotsubo syndrome (TS). TS is characterized by contractile dysfunction, which usually affects the apical region of the heart without obstruction of coronary artery, moderate increase in myocardial necrosis markers, prolonged QTc interval (in 50% of patients), sometimes elevation of ST segment (in 19% of patients), increase N-Terminal Pro-B-Type Natriuretic Peptide level, microvascular dysfunction, sometimes spasm of the epicardial coronary arteries (in 10% of patients), myocardial edema, and life-threatening ventricular arrhythmias (in 11% of patients). Stress cardiomyopathy is a rare disease, it is observed in 0.6 - 2.5% of patients with acute coronary syndrome. The occurrence of takotsubo syndrome is 9 times higher in women, who are aged 60-70 years old, than in men. The hospital mortality among patients with TS corresponds to 3.5% - 12%. Physical or emotional stress do not precede disease in all patients with TS. Most of patients with TS have neurological or mental illnesses. The level of catecholamines is increased in patients with TS, therefore, the occurrence of TS is associated with excessive activation of the adrenergic system. The negative inotropic effect of catecholamines is associated with the activation of β2 adrenergic receptors. An important role of the adrenergic system in the pathogenesis of TS is confirmed by studies which were performed using 125I-metaiodobenzylguanidine (125I -MIBG). TS causes edema and inflammation of the myocardium. The inflammatory response in TS is systemic. TS causes impaired coronary microcirculation and reduces coronary reserve. There is a reason to believe that an increase in blood viscosity may play an important role in the pathogenesis of microcirculatory dysfunction in patients with TS. Epicardial coronary artery spasm is not obligatory for the occurrence of TS. Cortisol, endothelin-1 and microRNAs are challengers for the role of TS triggers. A decrease in estrogen levels is a factor contributing to the onset of TS. The central nervous system appears to play an important role in the pathogenesis of TS.

Role of Exosomal miRNAs in Heart Failure

Heart failure is the terminal outcome of the majority of cardiovascular diseases, which lacks specific diagnostic biomarkers and therapeutic targets. It contributes to most of cardiovascular hospitalizations and death despite of the current therapy. Therefore, it is important to explore potential molecules improving the diagnosis and treatment of heart failure. MicroRNAs (miRNAs) are small non-coding RNAs that have been reported to be involved in regulating processes of heart failure. After the discovery of miRNAs in exosomes, the subcellular distribution analysis of miRNAs is raising researchers' attention. Growing evidence demonstrates that exosomal miRNAs may be promising diagnostic and therapeutic molecules for heart failure. This review summarizes the role of exosomal miRNAs in heart failure in the prospect of molecular and clinical researches.

Recent Development in Therapeutic Cardiac Patches

For the past decades, heart diseases remain the leading cause of death worldwide. In the adult mammalian heart, damaged cardiomyocytes will be replaced by non-contractile fibrotic scar tissues due to the poor regenerative ability of heart, causing heart failure subsequently. The development of tissue engineering has launched a new medical innovation for heart regeneration. As one of the most outstanding technology, cardiac patches hold the potential to restore cardiac function clinically. Consisted of two components: therapeutic ingredients and substrate scaffolds, the fabrication of cardiac patches requires both advanced bioactive molecules and biomaterials. In this review, we will present the most state-of-the-art cardiac patches and analysis their compositional details. The therapeutic ingredients will be discussed from cell sources to bioactive molecules. In the meanwhile, the recent advances to obtain scaffold biomaterials will be highlighted, including synthetic and natural materials. Also, we have focused on the challenges and potential strategies to fabricate clinically applicable cardiac patches.

Recent advances in cardiac biomarkers detection: From commercial devices to emerging technologies

Although cardiac pathologies are the major cause of death in the world, it remains difficult to provide a reliable diagnosis to prevent heart attacks. Rapid patient care and management in emergencies are critical to prevent dramatic consequences. Thus, relevant biomarkers such as cardiac troponin and natriuretic peptides are currently targeted by commercialized Point-Of-Care immunoassays. Key points still to be addressed concern cost, lack of standardization, and poor specificity, which could limit the reliability of the assays. Consequently, alternatives are emerging to address these issues. New probe molecules such as aptamers or molecularly imprinted polymers should allow a reduction in cost of the assays and an increase in reproducibility. In addition, the assay specificity and reliability could be improved by enabling multiplexing through the detection of several molecular targets in a single device.

Exosomes in Cardiovascular Diseases

Exosomes are nano-sized biovesicles of endocytic origin physiologically released by nearly all cell types into surrounding body fluids. They carry cell-specific cargos of protein, lipids, and genetic materials and can be selectively taken up by neighboring or distant cells. Since the intrinsic properties of exosomes are strictly influenced by the state of the parental cell and by the cellular microenvironment, the analysis of exosome origin and content, and their cell-targeting specificity, make them attractive as possible diagnostic and prognostic biomarkers. While the possible role of exosomes as messengers and a regenerative tool in cardiovascular diseases (CVDs) is actively investigated, the evidence about their usefulness as biomarkers is still limited and incomplete. Further complications are due to the lack of consensus regarding the most appropriate approach for exosome isolation and characterization, both important issues for their effective clinical translation. As a consequence, in this review, we will discuss the few information currently accessible about the diagnostic/prognostic potential of exosomes in CVDs and on the methodologies available for exosome isolation, analysis, and characterization.

Exosomes: A new horizon in modern medicine

Exosomes are a type of extracellular vesicles belonging to endocytic origin. These vesicles carry different biological cargo that play numerous physiological roles and is also indicative of different diseased state. Exosomes are considered as promising tools for therapeutic drug delivery, owing to their intrinsic features like stability, biocompatibility and a capacity of stealth. A clearer understanding of the composition, biogenesis and biology of exosomes can provide us with better insights into the pathophysiological, diagnostic, and therapeutic roles of these extracellular vesicles. In this review we have summarize existing literature regarding the production, efficacy, action mechanism, and potential therapeutic roles of exosomes in the contexts of various diseases such as cancer, renal disease, neurological disorders, cardio-vascular diseases, inflammatory diseases and some of the auto-immune diseases.

Circulating exosomal microRNAs as emerging non-invasive clinical biomarkers in heart failure: Mega bio-roles of a nano bio-particle

Exosomes are nano-sized extracellular vesicles containing a cell-specific biologically active cargo of proteins and genetic materials. Exosomes are constitutively released from almost all cell-types and affect neighboring or distant cells through a complex intercellular exchange of the genetic information and/or regulation of certain gene expressions that change the function and behavior of recipient cells. Those released into body fluids are the major mediators of intercellular communications. The success of the biological functions of exosomes is highly mediated by the effective transfer of microRNAs (miRs). Exosomes secreted by a damaged or diseased heart can exhibit alterations in the miRs' profile that may reflect the cellular origin and (patho)physiological state, as a "signature" or "fingerprint" of the donor cell. It has been shown that the transportation of cardiac-specific miRs in exosomes can be rapidly detected and measured, holding great potential as biomarkers in heart diseases. Currently, the search for new biomarkers of heart diseases remains a large and increasing enterprise. Notably, circulating exosomal miRs (Exo-miRs) have successfully gained huge interests for their diagnostic and prognostic potentials. The present review highlights circulating Exo-miRs explored for diagnosis/prognosis and outcome prediction in patients with heart failure (HF). To this end, we explain the feasibility of exosomes as clinical biomarkers, discuss the priority of circulating Exo-miRs over non-exosomal ones as a biomarker, and then outline reported circulating Exo-miRs having the biomarker function in HF patients, together with their mechanism of action. In conclusion, circulating Exo-miRs represent emerging diagnostic (Exo-miR-92b-5p, Exo-miR-146a, Exo-miR-181c, and Exo-miR-495) and prognostic (Exo-miR-192, Exo-miR-194, Exo-miR-34a, Exo-miR-425, Exo-miR-744) biomarkers for HF.

Stoking the Fire: How Dying Cells Propagate Inflammatory Signalling through Extracellular Vesicle Trafficking

Communication between dying cells and their environment is a critical process that promotes tissue homeostasis during normal cellular turnover, whilst during disease settings, it can contribute to inflammation through the release of intracellular factors. Extracellular vesicles (EVs) are a heterogeneous class of membrane-bound cell-derived structures that can engage in intercellular communication via the trafficking of bioactive molecules between cells and tissues. In addition to the well-described functions of EVs derived from living cells, the ability of dying cells to release EVs capable of mediating functions on target cells or tissues is also of significant interest. In particular, during inflammatory settings such as acute tissue injury, infection and autoimmunity, the EV-mediated transfer of proinflammatory cargo from dying cells is an important process that can elicit profound proinflammatory effects in recipient cells and tissues. Furthermore, the biogenesis of EVs via unique cell-death-associated pathways has also been recently described, highlighting an emerging niche in EV biology. This review outlines the mechanisms and functions of dying-cell-derived EVs and their ability to drive inflammation during various modes of cell death, whilst reflecting on the challenges and knowledge gaps in investigating this subgenre of extracellular vesicles research.

The Regulation of Exosome-Derived miRNA on Heterogeneity of Macrophages in Atherosclerotic Plaques

Exosomes are nanosized vesicles secreted by most cells, which can deliver a variety of functional lipids, proteins, and RNAs into the target cells to participate in complex intercellular communications. Cells respond to certain physical, chemical, and biological stimuli by releasing exosomes. Exosomes are rich in small molecules of RNA, including miRNAs and mRNAs, which have been demonstrated to have certain functions in recipient cells. Recent studies on single-cell RNA sequences have revealed the transcription and the heterogeneity of macrophages in Ldlr-/-mice fed with a high-fat diet. Five macrophage populations were found in the atherosclerotic plaques. It is worth noting that these subset populations of macrophages seem to be endowed with different functions in lipid metabolism and catabolism. A total of 100 differentially expressed mRNAs were selected for these subset populations. Importantly, these macrophage populations were also present in human advanced atherosclerosis. To clarify the specific functions and the regulatory mechanism of these macrophage populations, we extracted exosome RNAs from the plasma of patients with chronic coronary artery disease (CAD) and performed RNA sequencing analysis. Compared with the healthy control, a total of 14 miRNAs were significantly expressed in these patients. A total of 5,248 potential mRNAs were predicted by the bioinformatics platform. Next, we determined the outcome of the intersection of these predicted mRNAs with 100 mRNAs expressed in the above-mentioned five macrophage populations. Based on the screening of miRNA-mRNA pairs, a co-expression network was drawn to find out the key RNAs. Three down-regulated miRNAs and five up-regulated mRNAs were selected for validation by real-time RT-PCR. The results showed that the expression of miR-4498 in plasma exosomes was lower than that in the healthy control, and the expressions of Ctss, Ccr2 and Trem2 mRNA in peripheral blood mononuclear cells isolated from CAD patients were higher. In order to clarify the regulatory mechanism, we established a co-culture system in vitro. Studies have shown that the uptake of exosomes from CAD patients can up-regulate the expression of Ctss, Trem2, and Ccr2 mRNA in THP-1 cells induced by lipopolysaccharide. Our findings revealed a unique relationship between the transcriptional signature and the phenotypic heterogeneity of macrophage in the atherosclerotic microenvironment.

Circulating MicroRNAs: Biogenesis and Clinical Significance in Acute Myocardial Infarction

Acute myocardial infarction (AMI) causes many deaths around the world. Early diagnosis can prevent the development of AMI and provide theoretical support for the subsequent treatment. miRNAs participate in the AMI pathological processes. We aim to determine the early diagnostic and the prognostic roles of circulating miRNAs in AMI in the existing studies and summarize all the data to provide a greater understanding of their utility for clinical application. We reviewed current knowledge focused on the AMI development and circulating miRNA formation. Meanwhile, we collected and analyzed the potential roles of circulating miRNAs in AMI diagnosis, prognosis and therapeutic strategies. Additionally, we elaborated on the challenges and clinical perspectives of the application of circulating miRNAs in AMI diagnosis. Circulating miRNAs are stable in the circulation and have earlier increases of circulating levels than diagnostic golden criteria. In addition, they are tissue and disease-specific. All these characteristics indicate that circulating miRNAs are promising biomarkers for the early diagnosis of AMI. Although there are several limitations to be resolved before clinical use, the application of circulating miRNAs shows great potential in the early diagnosis and the prognosis of AMI.

Altered microRNA dynamics in acute coronary syndrome

INTRODUCTION

In the course of acute myocardial infarction (AMI) cardiomyocyte injury, activation and destruction of endothelial cells together with inflammation lead to miRNA expression alterations.

AIM

To assess levels of circulating cardiac-specific (miR-1) and endothelial-specific (miR-126) miRNAs in the acute phase of AMI and after a follow-up period.

MATERIAL AND METHODS

Seventeen AMI patients (mean age: 64.24 ±13.83 years, mean left ventricle ejection fraction (LVEF): 42.6 ±9.65%), treated with primary percutaneous coronary intervention within the first 12 h, had plasma miRNAs isolated (quantitative real-time PCR, Exiqon) on admission and after 19.2 ±5.9 weeks. Measurements were also performed in a control group of healthy volunteers matched for age and sex.

RESULTS

Concentrations of both miRNAs were significantly higher in AMI patients as compared to healthy controls: miR-1: 5.93 (3.15-14.92) vs. 1.46 (0.06-2.96), p = 0.04; miR-126: 4.5 (3.11-7.64) vs. 0.54 (0.36-0.99), p = 0.00003, respectively. Levels of both miRNAs significantly decreased after the follow-up period: miR-1: 5.93 (3.15-14.92) vs. 1.34 (0.04-2.34), p = 0.002; miR-126: 4.5 (3.11-7.64) vs. 1.18 (0.49-1.68), p = 0.0005). Moreover, miR-1 correlated positively with maximal troponin I concentration (r = 0.59, p = 0.02) and negatively with LVEF (r = -0.76, p = 0.0004).

CONCLUSIONS

In our study, miR-1 emerged as a marker of cardiomyocyte injury and loss of myocardial contractility, whereas dynamics of miR-126 concentration may reflect endothelial activation and damage in the most extreme stage of atherosclerosis, followed by angiogenesis in ischemic myocardium. However, to fully elucidate the role of miR-1 and miR-126 as biomarkers of AMI and future therapeutic targets, further research is required.

Nano-Vesicle (Mis)Communication in Senescence-Related Pathologies

Extracellular vesicles are a heterogeneous group of cell-derived membranous structures comprising of exosomes, apoptotic bodies, and microvesicles. Of the extracellular vesicles, exosomes are the most widely sorted and extensively explored for their contents and function. The size of the nanovesicular structures (exosomes) range from 30 to 140 nm and are present in various biological fluids such as saliva, plasma, urine etc. These cargo-laden extracellular vesicles arise from endosome-derived multivesicular bodies and are known to carry proteins and nucleic acids. Exosomes are involved in multiple physiological and pathological processes, including cellular senescence. Exosomes mediate signaling crosstalk and play a critical role in cell-cell communications. Exosomes have evolved as potential biomarkers for aging-related diseases. Aging, a physiological process, involves a progressive decline of function of organs with a loss of homeostasis and increasing probability of illness and death. The review focuses on the classic view of exosome biogenesis, biology, and age-associated changes. Owing to their ability to transport biological information among cells, the review also discusses the interplay of senescent cell-derived exosomes with the aging process, including the susceptibility of the aging population to COVID-19 infections.

Exosome: An Emerging Source of Biomarkers for Human Diseases

Exosomes are 30-120nm long endocytic membrane-derived vesicles, which are secreted by various types of cells and stably present in body fluids, such as plasma, urine, saliva and breast milk. Exosomes participate in intercellular communication. Recently accumulative studies have suggested that exosomes may serve as novel biomarkers for disease diagnosis and prognosis. Herein, we reviewed the biological features of exosomes, technologies for exosome isolation and identification, as well as progress in exosomal biomarker identification, highlighting the relevance of exosome to human diseases and significance and great potential in translational medicine.

Lionheart LincRNA alleviates cardiac systolic dysfunction under pressure overload

Recent high-throughput approaches have revealed a vast number of transcripts with unknown functions. Many of these transcripts are long noncoding RNAs (lncRNAs), and intergenic region-derived lncRNAs are classified as long intergenic noncoding RNAs (lincRNAs). Although Myosin heavy chain 6 (Myh6) encoding primary contractile protein is down-regulated in stressed hearts, the underlying mechanisms are not fully clarified especially in terms of lincRNAs. Here, we screen upregulated lincRNAs in pressure overloaded hearts and identify a muscle-abundant lincRNA termed Lionheart. Compared with controls, deletion of the Lionheart in mice leads to decreased systolic function and a reduction in MYH6 protein levels following pressure overload. We reveal decreased MYH6 results from an interaction between Lionheart and Purine-rich element-binding protein A after pressure overload. Furthermore, human LIONHEART levels in left ventricular biopsy specimens positively correlate with cardiac systolic function. Our results demonstrate Lionheart plays a pivotal role in cardiac remodeling via regulation of MYH6.

Kuwabara et al. identify a novel long intergenic noncoding RNA (lincRNA), termed Lionheart, upregulated in pressure overloaded hearts in mice. Deleting this gene results in decreased systolic function and reduction in MYH6 protein levels following pressure overload. They demonstrate that Lionheart interacts with PURA, preventing its binding to the promoter region of Myh6 locus, leading to reduced MYH6 protein expression.

Application of exosomes as liquid biopsy in clinical diagnosis

Liquid biopsy refers to the sampling and molecular analysis of the biofluids of circulating tumor cells, extracellular vesicles, nucleic acids, and so forth. Exosomes are small extracellular vesicles with sizes between 30–150 nm. They are secreted by multivesicular bodies through exocytosis in live cells and can participate in intercellular communication due to their contents, including nucleic acids, proteins, and lipids. Herein, we investigate publication frequencies on exosomes over the past 10 years, and review recent clinical studies on liquid biopsy of exosomes in the fields of oncology, pregnancy disorders, cardiovascular diseases, and organ transplantation. We also describe the advantages of exosomes as an effective liquid biopsy tool and the progression of exosome extraction methods. Finally, we depict the commercial development of exosome research and discuss the future role of exosomes in liquid biopsy.

miR-125 family regulates XIRP1 and FIH in response to myocardial infarction

MicroRNAs (miRNAs) are powerful regulators of protein expression. Many play important roles in cardiac development and disease. While several miRNAs and targets have been well characterized, the abundance of miRNAs and the numerous potential targets for each suggest that the vast majority of these interactions have yet to be described. The goal of this study was to characterize miRNA expression in the mouse heart after coronary artery ligation (LIG) and identify novel mRNA targets altered during the initial response to ischemic stress. We performed small RNA sequencing (RNA-Seq) of ischemic heart tissue 1 day and 3 days after ligation and identified 182 differentially expressed miRNAs. We then selected relevant mRNA targets from all potential targets by correlating miRNA and mRNA expression from a corresponding RNA-Seq data set. From this analysis we chose to focus, as proof of principle, on two miRNAs from the miR-125 family, miR-125a and miR-351, and two of their potential mRNA targets, Xin actin-binding repeat-containing protein 1 (XIRP1) and factor inhibiting hypoxia-inducible factor (FIH). We found miR-125a to be less abundant and XIRP1 more abundant after ligation. In contrast, the related murine miRNA miR-351 was substantially upregulated in response to ischemic injury, and FIH expression correspondingly decreased. Luciferase reporter assays confirmed direct interactions between these miRNAs and targets. In summary, we utilized a correlative analysis strategy combining miRNA and mRNA expression data to identify functional miRNA-mRNA relationships in the heart after ligation. These findings provide insight into the response to ischemic injury and suggest future therapeutic targets.

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.

Landscape of the long non-coding RNA transcriptome in human heart

Long non-coding RNAs (lncRNAs) have been revealed to play essential roles in the human cardiovascular system. However, information about their mechanisms is limited, and a comprehensive view of cardiac lncRNAs is lacking from a multiple tissues perspective to date. Here, the landscape of the lncRNA transcriptome in human heart was summarized. We summarized all lncRNA transcripts from publicly available human transcriptome resources (156 heart samples and 210 samples from 29 other tissues) and systematically analysed all annotated and novel lncRNAs expressed in heart. A total of 7485 lncRNAs whose expression was elevated in heart (HE lncRNAs) and 453 lncRNAs expressed in all 30 analysed tissues (EIA lncRNAs) were extracted. Using various bioinformatics resources, methods and tools, the features of these lncRNAs were discussed from various perspectives, including genomic structure, conservation, dynamic variation during heart development, cis-regulation, differential expression in cardiovascular diseases and cancers as well as regulation at transcriptional and post-transcriptional levels. Afterwards, all the features discussed above were integrated into a user-friendly resource named CARDIO-LNCRNAS (http://bio-bigdata.hrbmu.edu.cn/CARDIO-LNCRNAS/ or http://www.bio-bigdata.net/CARDIO-LNCRNAS/). This study represents the first global view of lncRNAs in the human cardiovascular system based on multiple tissues and sheds light on the role of lncRNAs in developments and heart disorders.

Circulating Non-coding RNAs and Cardiovascular Diseases

The discovery of noncoding RNAs (ncRNAs) including short microRNAs, long ncRNAs and circular RNAs has broaden our knowledge about mammalian genomes and transcriptomes. A growing number of evidence on aberrantly regulated ncRNAs in cardiovascular diseases has indicated that ncRNAs are critical contributors to cardiovascular pathophysiology. Moreover, multiple recent studies have reported that ncRNAs can be detected in the bloodstream that differs between health subjects and diseased patients and some of them are remarkably stable. Although our knowledge about the origin and function of the circulating ncRNAs is still limited, these molecules have been regarded as promising noninvasive biomarker for risk stratification, diagnosis and prognosis of various cardiovascular diseases. In this chapter, we have described biological characteristics of circulating ncRNAs and discussed current trends and future prospects for the usage of circulating ncRNAs as biomarkers for common cardiovascular diseases.

Cardiovascular Exosomes and MicroRNAs in Cardiovascular Physiology and Pathophysiology

Cardiac exosomes mediate cell-to-cell communication, stimulate or inhibit the activities of target cells, and affect myocardial hypertrophy, injury and infarction, ventricular remodeling, angiogenesis, and atherosclerosis. The exosomes that are released in the heart from cardiomyocytes, vascular cells, fibroblasts, and resident stem cells are hypoimmunogenic, are physiologically more stable than cardiac cells, can circulate in the body, and are able to cross the blood-brain barrier. Exosomes utilize three mechanisms for cellular communication: (1) internalization by cells, (2) direct fusion to the cell membrane, and (3) receptor-ligand interactions. Cardiac exosomes transmit proteins, mRNA, and microRNAs to other cells during both physiological and pathological process. Cardiac-specific exosome miRNAs can regulate the expression of sarcomeric genes, ion channel genes, autophagy, anti-apoptotic and anti-fibrotic activity, and angiogenesis. This review discusses the role of exosomes and microRNAs in normal myocardium, myocardial injury and infarction, atherosclerosis, and the importance of circulating microRNAs as biomarkers of cardiac disease. Graphical Abstract.

Small but significant: Insights and new perspectives of exosomes in cardiovascular disease

Cardiovascular diseases (CVDs) are a major health problem worldwide, and health professionals are still actively seeking new and effective approaches for CVDs treatment. Presently, extracellular vesicles, particularly exosomes, have gained its popularity for CVDs treatment because of their function as messengers for inter- and extra-cellular communications to promote cellular functions in cardiovascular system. However, as a newly developed field, researchers are still trying to fully understand the role of exosomes, and their mechanism in mediating cardiac repair process. Therefore, a comprehensive review of this topic can be timely and favourable. In this review, we summarized the basic biogenesis and characterization of exosomes and then further extended the focus on the circulating exosomes in cellular communication and stem cell-derived exosomes in cardiac disease treatment. In addition, we covered interactions between the heart and other organs through exosomes, leading to the diagnostic characteristics of exosomes in CVDs. Future perspectives and limitations of exosomes in CVDs were also discussed with a special focus on exploring the potential delivery routes, targeting the injured tissue and engineering novel exosomes, as well as its potential as one novel target in the metabolism-related puzzle.

Methods for the Determination of the Purity of Exosomes

BACKGROUND

Exosomes open exciting new opportunities for advanced drug transport and targeted release. Furthermore, exosomes may be used for vaccination, immunosuppression or wound healing. To fully utilize their potential as drug carriers or immune-modulatory agents, the optimal purity of exosome preparations is of crucial importance.

METHODS

Articles describing the isolation and purification of exosomes were retrieved from the PubMed database.

RESULTS

Exosomes are often separated from biological fluids containing high concentrations of proteins, lipids and other molecules that keep vesicle purification challenging. A great number of purification protocols have been published, however, their outcome is difficult to compare because the assessment of purity has not been standardized. In this review, we first give an overview of the generation and composition of exosomes, as well as their multifaceted biological functions that stimulated various medical applications. Finally, we describe various methods that have been used to purify small vesicles and to assess the purity of exosome preparations and critically compare the quality of these evaluation protocols.

CONCLUSION

Combinations of various techniques have to be applied to reach the required purity and quality control of exosome preparations.

Hypoxia-challenged MSC-derived exosomes deliver miR-210 to attenuate post-infarction cardiac apoptosis

BACKGROUND

Myocardial infarction (MI) is a major cause of death worldwide. Although percutaneous coronary intervention and coronary artery bypass grafting can prolong life, cardiac damage persists. In particular, cardiomyocytes have no regenerative capacity. Mesenchymal stem cells (MSCs) are attractive candidates for the treatment of MI. The manner by which MSCs exert a beneficial effect upon injured cells is a source of continued study.

METHODS

After the isolation and identification of exosomes from MSCs, the expression of miR-210 was determined by microarray chip. Subsequently, gain- and loss-function approaches were conducted to detect the role of exosomes and exosomal-miR-210 in cell proliferation and apoptosis of cardiomyocytes, as well as the MI in vivo. Dual-Luciferase Report Gene System was used to demonstrate the target gene of miR-210.

RESULTS

We tested the hypothesis that MSC-derived exosomes transfer specific miRNA to protect cardiomyocytes from apoptotic cell death. Interestingly, direct cardiac injection of MSC exosomes reduced infarct size and improved heart function after coronary ligation. In vitro, the MSC exosomes enhanced cardiomyocyte survival to hypoxia. Confirmation of exosome uptake in myocytes was confirmed. Dual-luciferase reporter assay implicated miR-210 as a mediator of the therapeutic effect and AIFM3 as a downstream target. Treatment with miR-210 overexpressing MSC exosomes improved myocyte protection to both in vitro and in vivo stress. Furthermore, the endogenous and exogenous miR-210 had the same therapeutic effects.

CONCLUSION

These results demonstrated that the beneficial effects offered by MSC-exosomes transplantation after MI are at least partially because of excreted exosome containing mainly miR-210.

Urinary Biomarkers in Bladder Cancer: Where Do We Stand and Potential Role of Extracellular Vesicles

Extracellular vesicles (EVs) are small membrane vesicles released by all cells and involved in intercellular communication. Importantly, EVs cargo includes nucleic acids, lipids, and proteins constantly transferred between different cell types, contributing to autocrine and paracrine signaling. In recent years, they have been shown to play vital roles, not only in normal biological functions, but also in pathological conditions, such as cancer. In the multistep process of cancer progression, EVs act at different levels, from stimulation of neoplastic transformation, proliferation, promotion of angiogenesis, migration, invasion, and formation of metastatic niches in distant organs, to immune escape and therapy resistance. Moreover, as products of their parental cells, reflecting their genetic signatures and phenotypes, EVs hold great promise as diagnostic and prognostic biomarkers. Importantly, their potential to overcome the current limitations or the present diagnostic procedures has created interest in bladder cancer (BCa). Indeed, cystoscopy is an invasive and costly technique, whereas cytology has poor sensitivity for early staged and low-grade disease. Several urine-based biomarkers for BCa were found to overcome these limitations. Here, we review their potential advantages and downfalls. In addition, recent literature on the potential of EVs to improve BCa management was reviewed and discussed.

Disease severity-related alterations of cardiac microRNAs in experimental pulmonary hypertension

Right ventricular (RV) failure is the primary cause of death in pulmonary arterial hypertension (PAH). We hypothesized that heart‐relevant microRNAs, that is myomiRs (miR‐1, miR‐133a, miR‐208, miR‐499) and miR‐214, can have a role in the right ventricle in the development of PAH. To mimic PAH, male Wistar rats were injected with monocrotaline (MCT, 60 mg/kg, s.c.); control group received vehicle. MCT rats were divided into two groups, based on the clinical presentation: MCT group terminated 4 weeks after MCT administration and prematurely terminated group (ptMCT) displaying signs of terminal disease. Myocardial damage genes and candidate microRNAs expressions were determined by RT‐qPCR. Reduced blood oxygen saturation, breathing disturbances, RV enlargement as well as elevated levels of markers of myocardial damage confirmed PH in MCT animals and were more pronounced in ptMCT. MyomiRs (miR‐1/miR‐133a/miR‐208a/miR‐499) were decreased and the expression of miR‐214 was increased only in ptMCT group (P < 0.05). The myomiRs negatively correlated with Fulton index as a measure of RV hypertrophy in MCT group (P < 0.05), whereas miR‐214 showed a positive correlation (P < 0.05). We conclude that the expression of determined microRNAs mirrored the disease severity and targeting their pathways might represent potential future therapeutic approach in PAH.

microRNA neural networks improve diagnosis of acute coronary syndrome (ACS)

BACKGROUND

Cardiac troponins are the preferred biomarkers of acute myocardial infarction. Despite superior sensitivity, serial testing of Troponins to identify patients suffering acute coronary syndromes is still required in many cases to overcome limited specificity. Moreover, unstable angina pectoris relies on reported symptoms in the troponin-negative group. In this study, we investigated genome-wide miRNA levels in a prospective cohort of patients with clinically suspected ACS and determined their diagnostic value by applying an in silico neural network.

METHODS

PAXgene blood and serum samples were drawn and hsTnT was measured in patients at initial presentation to our Chest-Pain Unit. After clinical and diagnostic workup, patients were adjudicated by senior cardiologists in duty to their final diagnosis: STEMI, NSTEMI, unstable angina pectoris and non-ACS patients. ACS patients and a cohort of healthy controls underwent deep transcriptome sequencing. Machine learning was implemented to construct diagnostic miRNA classifiers.

RESULTS

We developed a neural network model which incorporates 34 validated ACS miRNAs, showing excellent classification results. By further developing additional machine learning models and selecting the best miRNAs, we achieved an accuracy of 0.96 (95% CI 0.96-0.97), sensitivity of 0.95, specificity of 0.96 and AUC of 0.99. The one-point hsTnT value reached an accuracy of 0.89, sensitivity of 0.82, specificity of 0.96, and AUC of 0.96.

CONCLUSIONS

Here we show the concept of neural network based biomarkers for ACS. This approach also opens the possibility to include multi-modal data points to further increase precision and perform classification of other ACS differential diagnoses.

MicroRNAs in cardiovascular disease

Cardiovascular disease (CVD) remains the predominant cause of human morbidity and mortality in developed countries. Currently, microRNAs have been investigated in many diseases as well-promising biomarkers for diagnosis, prognosis, and disease monitoring. Plenty studies have been designed so as to elucidate the properties of microRNAs in the classification and risk stratification of patients with CVD and also to evaluate their potentials in individualized management and guide treatment decisions. Therefore, in this review article, we aimed to present the most recent data concerning the role of microRNAs as potential novel biomarkers for cardiovascular disease.

Circulating MicroRNA Profiling in Non-ST Elevated Coronary Artery Syndrome Highlights Genomic Associations with Serial Platelet Reactivity Measurements

Changes in platelet physiology are associated with simultaneous changes in microRNA concentrations, suggesting a role for microRNA in platelet regulation. Here we investigated potential associations between microRNA and platelet reactivity (PR), a marker of platelet function, in two cohorts following a non-ST elevation acute coronary syndrome (NSTE-ACS) event. First, non-targeted microRNA concentrations and PR were compared in a case (N = 77) control (N = 76) cohort within the larger TRILOGY-ACS trial. MicroRNA significant in this analysis plus CVD-associated microRNAs from the literature were then quantified by targeted rt-PCR in the complete TRILOGY-ACS cohort (N = 878) and compared with matched PR samples. Finally, microRNA significant in the non-targeted & targeted analyses were verified in an independent post NSTE-ACS cohort (N = 96). From the non-targeted analysis, 14 microRNAs were associated with PR (Fold Change: 0.91–1.27, p-value: 0.004–0.05). From the targeted analysis, five microRNAs were associated with PR (Beta: −0.09–0.22, p-value: 0.004–0.05). Of the 19 significant microRNAs, three, miR-15b-5p, miR-93 and miR-126, were consistently associated with PR in the TRILOGY-ACS and independent Singapore post-ACS cohorts, suggesting the measurement of circulating microRNA concentrations may report on dynamic changes in platelet biology following a cardiovascular ischemic event.

Noncoding RNAs as Biomarkers for Acute Coronary Syndrome

Acute coronary syndrome (ACS), consisting of acute myocardial infarction and unstable angina, is the most dangerous and fatal form of coronary heart disease. Acute coronary syndrome has sudden onset and rapid development, which may lead to malignant life-threatening conditions at any time. Therefore, early detection and diagnosis are critical for patients with ACS. Recent studies have found that noncoding RNA is of great significance in the diagnosis and treatment of cardiovascular diseases. In this review, we summarized recent data on circulating noncoding RNAs (including microRNA, long noncoding RNA, and circular RNA) as diagnostic and prognostic markers in ACS including acute myocardial infarction and unstable angina. Specifically, microRNAs (miRNAs) as diagnostic markers are divided into three types: miRNAs of increased expression in ACS, miRNAs of decreased expression in ACS, and miRNAs of contradictory expression in ACS. Moreover, we described these miRNAs of increased expression in ACS based on miRNAs family. This review may result in a great guidance of noncoding RNAs as biomarkers for ACS in clinical practice.

The Diagnostic Value of Mir-133a in ST Elevation and Non-ST Elevation Myocardial Infarction: A Meta-Analysis

Numerous studies have reported correlations between plasma microRNA signatures and cardiovascular disease. MicroRNA-133a (Mir-133a) has been researched extensively for its diagnostic value in acute myocardial infarction (AMI). While initial results seemed promising, more recent studies cast doubt on the diagnostic utility of Mir-133a, calling its clinical prospects into question. Here, the diagnostic potential of Mir-133a was analyzed using data from multiple papers. Medline, Embase, and Web of Science were systematically searched for publications containing “Cardiovascular Disease”, “MicroRNA”, “Mir-133a” and their synonyms. Diagnostic performance was assessed using area under the summary receiver operator characteristic curve (AUC), while examining the impact of age, sex, final diagnosis, and time. Of the 753 identified publications, 9 were included in the quantitative analysis. The pooled AUC for Mir-133a was 0.73. Analyses performed separately on studies using healthy vs. symptomatic controls yielded pooled AUCs of 0.89 and 0.68, respectively. Age and sex were not found to significantly affect diagnostic performance. Our findings indicate that control characteristics and methodological inconsistencies are likely the causes of incongruent reports, and that Mir-133a may have limited use in distinguishing symptomatic patients from those suffering AMI. Lastly, we hypothesized that Mir-133a may find a new use as a risk stratification biomarker in patients with specific subsets of non-ST elevation myocardial infarction (NSTEMI).

Noncoding RNAs versus Protein Biomarkers in Cardiovascular Disease

The development of more sensitive protein biomarker assays results in continuous improvements in detectability, extending the range of clinical applications to the detection of subclinical cardiovascular disease (CVD). However, these efforts have not yet led to improvements in risk assessment compared with existing risk scores. Noncoding RNAs (ncRNAs) have been assessed as biomarkers, and miRNAs have attracted most attention. More recently, other ncRNA classes have been identified, including long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs). Here, we compare emerging ncRNA biomarkers in the cardiovascular field with protein biomarkers for their potential in clinical application, focusing on myocardial injury.

CircMACF1 Attenuates Acute Myocardial Infarction Through miR-500b-5p-EMP1 Axis

It is widely accepted that circular RNA (circRNA) plays an important role in cardiovascular diseases. Therefore, this experiment aimed to investigate the pathogenesis of circMACF1 in acute myocardial infarction (AMI). qRT-PCR and immunoblotting were used to detect the expression levels of circMACF1, miR-500b-5p, and epithelial membrane protein 1 (EMP1). The role of circMACF1, miR-500b-5p, and EMP1 in cardiomyocyte apoptosis was assessed using annexin V-FITC/PI. Echocardiographic assessment, serum creatine kinase MB (CK-MB) and lactate dehydrogenase (LDH), myocardial infarct size, and TUNEL staining were applied in our research. In the MI group, the expression levels of circMACF1 and EMP1 were decreased with the increasing expression level of miR-500b-5p. CircMACF1 upregulated the expression of EMP1 as a sponge of miR-500b-5p, and circMACF1 was a direct target of miR-500b-5p. CircMACF1 impaired the progression of AMI by modulating the miR-500b-5p/EMP1 axis. CircMACF1 may be a potential therapeutic target for treating AMI. Graphical Abstract CircMACF1 upregulated EMP1 expression by sponge miR-500b-5p.

Vascular Smooth Muscle Cell-Derived Exosomal MicroRNAs Regulate Endothelial Cell Migration Under PDGF Stimulation

Intercellular communication between vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) is essential for the maintenance of vascular homeostasis. The presence of exosomes, a recently discovered player in vascular cell communication, has been associated with vascular disease progression. However, the detailed mechanism of how the signal mediated by exosomes affects the function of vascular cells during vascular pathogenesis is yet to be further understood. In this study, we investigated the expression of exosomal microRNAs (miRNAs) secreted by VSMCs and their functional relevance to ECs in pathogenesis, including their role in processes such as platelet-derived growth factor (PDGF) stimulation. We observed that PDGF stimulation contributes to a change in exosomal miRNA release from VSMCs; specifically, miR-1246, miR-182, and miR-486 were deficient in exosomes derived from PDGF-stimulated VSMCs. The reduced miRNA expression in these exosomes is associated with an increase in EC migration. These findings increase our understanding of exosome-mediated crosstalk between vascular cells under a pathological condition.

Exosomes Derived From Epigallocatechin Gallate-Treated Cardiomyocytes Attenuated Acute Myocardial Infarction by Modulating MicroRNA-30a

Background

Ischemia-derived exosomes can restrict excessive autophagy by transferring microRNA-30a (miR30a) to cells. Reports have confirmed that epigallocatechin gallate (EGCG) alleviates acute myocardial infarction (AMI) by regulating autophagy; however, research evaluating the communication with cardiomyocytes and exosomes is lacking. This study aimed to explore whether exosomes derived from EGCG-treated cardiomyocytes mitigated AMI by adjusting miR30a to inactivate apoptosis and autophagy.

Methods

Exosomes were extracted from cardiomyocytes, cultured either in control or AMI condition, with or without EGCG pretreatment. The exosome characteristics were analyzed by nanoparticle tracking analyses and transmission electron microscopy. The change in miR30a in cells and exosomes was demonstrated by qRT-PCR. H9c2 or stable miR30a knockdown (miR30a^KD) cell lines were incubated with exosomes derived from EGCG-treated cardiomyocytes in vitro or in vivo. The effect of EGCG and exosomes on I/R-induced cardiomyocyte apoptosis and autophagy was assessed.

Results

EGCG improved the activity of cardiomyocytes, and increased average diameter, concentration, miR30a mRNA level, and specific protein expression in AMI-derived exosomes produced by cardiomyocytes. Moreover, the coincubation of AMI cells with EGCG or exosomes derived from EGCG-treated cardiomyocytes attenuated cardiomyocyte apoptosis and autophagy.

Conclusions

The findings showed that EGCG upregulates miR30a, which was efficiently transferred via exosomes between cardiomyocytes, thereby contributing to the suppression of apoptosis and autophagy. By focusing on the cardiomyocyte microenvironment, we identified a new target of EGCG alleviating AMI by regulating apoptosis and autophagy.

Novel Invasive and Noninvasive Cardiac-Specific Biomarkers in Obesity and Cardiovascular Diseases

Cardiovascular disease (CVD) is the leading cause of fatality and disability worldwide regardless of gender. Obesity has reached epidemic proportions in population across different regions. According to epidemiological studies, CVD risk markers in childhood obesity are one of the significant risk factors for adulthood CVD, but have received disproportionally little attention. This review has examined the evidence for the presence of traditional cardiac biomarkers (nonspecific; lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, creatine kinase, myoglobulin, glycogen phosphorylase isoenzyme BB, myosin light chains, ST2, and ischemia-modified albumin) and novel emerging cardiac-specific biomarkers (cardiac troponins, natriuretic peptides, heart-type fatty acid-binding protein, and miRNAs). Besides, noninvasive anatomical and electrophysiological markers (carotid intima-media thickness, coronary artery calcification, and heart rate variability) in CVDs and obesity are also discussed. Modifiable and nonmodifiable risk factors associated with metabolic syndrome in the progression of CVD, such as obesity, diabetes, hypertension, dyslipidemia, oxidative stress, inflammation, and adipocytokines are also outlined. These underlying prognostic risk factors predict the onset of future microvascular and macrovascular complications. The understanding of invasive and noninvasive cardiac-specific biomarkers and the risk factors may yield valuable insights into the pathophysiology and prevention of CVD in a high-risk obese population at an early stage.