MicroRNAs in heart failure: is the picture becoming less miRky?

Evaluating Biomarkers as Tools for Early Detection and Prognosis of Heart Failure: A Comprehensive Review

There is a high prevalence of heart failure (HF) worldwide, which has significant consequences for healthcare costs, patient death and quality of life. Therefore, there has been much focus on finding and using biomarkers for early diagnosis, prognostication and therapy of HF. This overview of the research presents a thorough examination of the current state of HF biomarkers and their many uses. Their function in diagnosing HF, gauging its severity and monitoring its response to therapy are all discussed. Particularly promising in HF diagnosis and risk stratification are the cardiac-specific biomarkers, B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide. Markers of oxidative stress, extracellular matrix, renal function, inflammation and cardiac peptides have shown promise in evaluating HF severity and prognosis. MicroRNAs and insulin-like growth factor are two emerging biomarkers that have shown potential in helping with HF diagnosis and prognosis.

MicroRNAs are associated with cardiac biomarkers, cardiac structure and function and incident outcomes in heart failure

AIMS

The association between microRNAs (miRNAs) and established cardiac biomarkers is largely unknown. We aimed to measure the association between plasma miRNAs and N-terminal pro-B-type natriuretic peptide (NT-proBNP), cardiac troponin I, soluble urokinase-type plasminogen activator receptor (suPAR), and galectin-3 with cardiac structure and function and clinical outcomes.

METHODS AND RESULTS

We quantified 32 plasma miRNAs using the FirePlex miRNA assay and measured biomarkers in 139 individuals with symptomatic heart failure (HF). We used principal component (PC) analysis and linear regression to evaluate the association between miRNAs and biomarkers with ventricular size and function by echocardiography and Cox modelling for the incidence of a first composite event of HF hospitalization, heart transplant, left ventricular assist device implant, or death. The mean (standard deviation) age at baseline was 64.3 (12.4) years, 33 (24%) were female, and 122 (88%) were White. A total of 45 events occurred over a median follow-up of 368 (interquartile range 234, 494) days. Baseline NT-proBNP (β = -2.0; P = 0.001) and miRNA PC2 (β = 2.6; P = 0.002) were associated with baseline left ventricular ejection fraction. NT-proBNP (β = 20.6; P = 0.0004), suPAR (β = -39.6; P = 0.005), and PC4 (β = 21.1; P = 0.02) were associated with baseline left ventricular end-diastolic volumes. NT-proBNP [hazard ratio (HR) 1.67, 95% confidence interval (CI) 1.28-2.18, P = 0.0002], galectin-3 (HR 2.02, 95% CI 1.05-3.91, P = 0.036), PC3 (HR 1.75, 95% CI 1.23-2.49, P = 0.002), and PC4 (HR 1.67, 95% CI 1.1-2.52, P = 0.016) were independently associated with incident events.

CONCLUSIONS

Biomarkers and miRNA PCs are associated with cardiac structure and function and incident cardiovascular outcomes. Combining information from miRNAs provides prognostic information beyond biomarkers in HF.

MicroRNA-30d and -483-3p for bi-ventricular remodelling and miR-126-3p for pulmonary hypertension in advanced heart failure

AIMS

MicroRNAs play a role in pathogenic mechanisms leading to heart failure. We measured a panel of 754 miRNAs in the myocardial tissue and in the serum of patients with heart failure with reduced ejection fraction due to dilatative idiopathic cardiomyopathy (DCM, N = 10) or ischaemic cardiomyopathy (N = 3), referred to left ventricular assist device implant. We aim to identify circulating miRNAs with high tissue co-expression, significantly associated to echocardiographic and haemodynamic measures.

METHODS AND RESULTS

We have measured a panel of 754 miRNAs in the myocardial tissue [left ventricular (LV) apex] and in the serum obtained at the same time in a well selected study population of end-stage heart failure with reduced ejection fraction due to either DCM or ischaemic cardiomyopathy, referred to continuous flow left ventricular assist device implant. We observed moderate agreement for miR-30d, miR-126-3p, and miR-483-3p. MiR-30d was correlated to LV systolic as well as diastolic volumes (r = 0.78, P = 0.001 and r = 0.80, P = 0.005, respectively), while miR-126-3p was associated to mPAP and PCWP (r = -0.79, P = 0.007 and r = -0.80, P = 0.005, respectively). Finally, serum miR-483-3p had an association with right ventricular end diastolic diameter (r = -0.73, P = 0.02) and central venous pressure (CVP) (r - 0.68 p 0.03).

CONCLUSIONS

In patients with DCM, few miRNAs are co-expressed in serum and tissue: They are related to LV remodelling (miR-30d), post-capillary pulmonary artery pressure (miR-126-3p), and right ventricular remodelling/filling pressures (miR-483-3p). Further studies are needed to confirm their role in diagnosis, prognosis or as therapeutic targets in heart failure with reduced ejection fraction.

Novel Biomarkers in Early Detection of Heart Failure: A Narrative Review

Heart failure (HF) represents a significant global health challenge, characterized by a variety of symptoms resulting from cardiac dysfunction. This dysfunction often leads to systemic and pulmonary congestion. The pathophysiology of HF is complex, involving stimulation of the sympathetic nervous system, which is insufficiently balanced by the release of natriuretic peptide. This imbalance leads to progressive hypertrophy and dilatation of the heart's chambers, impairing its pumping efficiency and increasing the risk of arrhythmias and conduction disorders. The prevalence of HF is exceptionally high in industrialized nations and is expected to increase owing to an aging population and advancements in diagnostic methods. This study emphasizes the critical role of early diagnosis in reducing morbidity and mortality associated with HF, focusing specifically on the evolving importance of biomarkers in managing this condition. Biomarkers have played a key role in transforming the diagnosis and treatment of HF. Traditional biomarkers such as b-type natriuretic peptide and N-terminal pro-b-type natriuretic peptide have been widely adopted for their cost-effectiveness and ease of access. However, the rise of novel biomarkers such as growth differentiation factor 15 and adrenomedullin has shown promising results, offering superior sensitivity and specificity. These new biomarkers enhance diagnostic accuracy, risk stratification, and prognostic evaluation in HF patients. Despite these advancements, challenges remain, such as limited availability, high costs, and the need for further validation in diverse patient populations. Through a comprehensive literature review across databases such as PubMed, Google Scholar, and the Cochrane Library, this study compiles and analyzes data from 18 relevant studies, offering a detailed understanding of the current state of HF biomarkers. The study examines both traditional and emerging biomarkers such as galectin-3 and soluble suppression of tumorigenicity 2 in HF, exploring their clinical roles and impact on patient outcomes.

Modulation of miR-29 influences myocardial compliance likely through coordinated regulation of calcium handling and extracellular matrix

MicroRNAs (miRNAs) control the expression of diverse subsets of target mRNAs, and studies have found miRNA dysregulation in failing hearts. Expression of miR-29 is abundant in heart, increases with aging, and is altered in cardiomyopathies. Prior studies demonstrate that miR-29 reduction via genetic knockout or pharmacologic blockade can blunt cardiac hypertrophy and fibrosis in mice. Surprisingly, this depended on specifically blunting miR-29 actions in cardiomyocytes versus fibroblasts. To begin developing more translationally relevant vectors, we generated a novel transgene-encoded miR-29 inhibitor (TuD-29) that can be incorporated into a viral-mediated gene therapy for cardioprotection. Here, we corroborate that miR-29 expression and activity is higher in cardiomyocytes versus fibroblasts and demonstrate that TuD-29 effectively blunts hypertrophic responses in cultured cardiomyocytes and mouse hearts. Furthermore, we found that adeno-associated virus (AAV)-mediated miR-29 overexpression in mouse hearts induces early diastolic dysfunction, whereas AAV:TuD-29 treatment improves cardiac output by increasing end-diastolic and stroke volumes. The integration of RNA sequencing and miRNA-target interactomes reveals that miR-29 regulates genes involved in calcium handling, cell stress and hypertrophy, metabolism, ion transport, and extracellular matrix remodeling. These investigations support a likely versatile role for miR-29 in influencing myocardial compliance and relaxation, potentially providing a unique therapeutic avenue to improve diastolic function in heart failure patients.

Ginsenoside Rb2 improves heart failure by down-regulating miR-216a-5p to promote autophagy and inhibit apoptosis and oxidative stress

BACKGROUND

Ginsenoside Rb2 is beneficial in cardiovascular disease treatment, yet its role in heart failure (HF) is obscure. This study aimed to investigate the effect and mechanism of ginsenoside Rb2 on HF.

METHODS

The left anterior descending branch-ligated HF rat model and oxygen-glucose deprivation/reoxygenation (OGD/R) H9c2 cell model were constructed. Ginsenoside Rb2 were applied for intervention. Heart function indexes, miR-216a-5p expression, autophagy, oxidative stress, apoptosis, cell morphology, and proliferation were detected to explore the effect of ginsenoside Rb2 on HF. Overexpression of miR-216a-5p was employed to explore the specific mechanism of ginsenoside Rb2 on HF.

RESULTS

Ginsenoside Rb2 improved the heart function of HF rats, including the reduction of heart rate, LVEDP, and heart weight/body weight ratio, and the increase of LVSP, +dP/dtmax, -dP/dtmax, LVEF, and LVFS. It also down-regulated miR-216a-5p expression and enhanced OGD/R-induced cardiomyocyte viability. Ginsenoside Rb2 up-regulated Bcl2, LC3B II/I, and Beclin1, and down-regulated Bax, Caspase-3, and p62 in the myocardium of HF rats and OGD/R-induced H9c2 cells. Moreover, ginsenoside Rb2 increased the levels of SOD and CAT, but decreased the levels of MDA and ROS in the myocardium of HF rats and OGD/R-induced H9c2 cells. However, overexpression of miR-216a-5p promoted the apoptosis and oxidative stress of cardiomyocytes and inhibited autophagy, thus reversing the therapeutic effect of ginsenoside Rb2 on HF in vivo and in vitro.

CONCLUSION

Ginsenoside Rb2 demonstrated potential as a therapeutic intervention for HF by enhancing autophagy and reducing apoptosis and oxidative stress through miR-216a-5p downregulation. Further research could explore its application in clinical trials and investigate the complex mechanism networks underlying its effects.

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 Role of miRNA Expression Profile in Sudden Cardiac Death Cases

Sudden cardiac death (SCD) is one of the leading causes of death in the world and for this reason it has attracted the attention of numerous researchers in the field of legal medicine. It is not easy to determine the cause in a SCD case and the available methods used for diagnosis cannot always give an exhaustive answer. In addition, the molecular analysis of genes does not lead to a clear conclusion, but it could be interesting to focus attention on the expression level of miRNAs, a class of non-coding RNA of about 22 nucleotides. The role of miRNAs is to regulate the gene expression through complementary binding to 3'-untraslated regions of miRNAs, leading to the inhibition of translation or to mRNA degradation. In recent years, several studies were performed with the aim of exploring the use of these molecules as biomarkers for SCD cases, and to also distinguish the causes that lead to cardiac death. In this review, we summarize experiments, evidence, and results of different studies on the implication of miRNAs in SCD cases. We discuss the different biological starting materials with their respective advantages and disadvantages, studying miRNA expression on tissue (fresh-frozen tissue and FFPE tissue), circulating cell-free miRNAs in blood of patients affected by cardiac disease at high risk of SCD, and exosomal miRNAs analyzed from serum of people who died from SCD.

Extracellular Vesicle MicroRNAs in Heart Failure: Pathophysiological Mediators and Therapeutic Targets

Extracellular vesicles (EVs) are emerging mediators of intracellular and inter-organ communications in cardiovascular diseases (CVDs), especially in the pathogenesis of heart failure through the transference of EV-containing bioactive substances. microRNAs (miRNAs) are contained in EV cargo and are involved in the progression of heart failure. Over the past several years, a growing body of evidence has suggested that the biogenesis of miRNAs and EVs is tightly regulated, and the sorting of miRNAs into EVs is highly selective and tightly controlled. Extracellular miRNAs, particularly circulating EV-miRNAs, have shown promising potential as prognostic and diagnostic biomarkers for heart failure and as therapeutic targets. In this review, we summarize the latest progress concerning the role of EV-miRNAs in HF and their application in a therapeutic strategy development for heart failure.

Crosstalk between endoplasmic reticulum stress and non-coding RNAs in cardiovascular diseases

Cells are exposed to various pathological stimulus within the cardiovascular system that challenge cells to adapt and survive. Several of these pathological stimulus alter the normal function of the endoplasmic reticulum (ER), leading to the accumulation of unfolded and misfolded proteins, thus triggering the unfolded protein response (UPR) to cope with the stress or trigger apoptosis of damaged cells. Downstream components of the UPR regulate transcription and translation reprogramming to ensure selective gene expression in response to pathological stimulus, including the expression of non-coding RNAs (ncRNAs). The ncRNAs play crucial roles in regulating transcription and translation, and their aberrant expression is associated with the development of cardiovascular disease (CVD). Notably, ncRNAs and ER stress can modulate each other and synergistically affect the development of CVD. Therefore, studying the interaction between ER stress and ncRNAs is necessary for effective prevention and treatment of CVD. In this review, we discuss the UPR signaling pathway and ncRNAs followed by the interplay regulation of ER stress and ncRNAs in CVD, which provides further insights into the understanding of the pathogenesis of CVD and therapeutic strategies. This article is categorized under: RNA in Disease and Development > RNA in Disease.

Targeting and delivery of microRNA-targeting antisense oligonucleotides in cardiovascular diseases

Discovered three decades ago, microRNAs (miRNAs) are now recognized as key players in the pathophysiology of multiple human diseases, including those affecting the cardiovascular system. As such, miRNAs have emerged as promising therapeutic targets for preventing the onset and/or progression of several cardiovascular diseases. Anti-miRNA antisense oligonucleotides or "antagomirs" precisely block the activity of specific miRNAs and are therefore a promising therapeutic strategy to repress pathological miRNAs. In this review, we describe advancements in antisense oligonucleotide chemistry that have significantly improved efficacy and safety. Moreover, we summarize recent approaches for the targeted delivery of antagomirs to cardiovascular tissues, highlighting major advantages as well as limitations of viral (i.e., adenovirus, adeno-associated virus, and lentivirus) and non-viral (i.e., liposomes, extracellular vesicles, and polymer nanoparticles) delivery systems. We discuss recent preclinical studies that use targeted antagomir delivery systems to treat three major cardiovascular diseases (atherosclerosis, myocardial infarction, and cardiac hypertrophy, including hypertrophy caused by hypertension), highlighting therapeutic results and discussing challenges that limit clinical applicability.

MicroRNA-19 upregulation attenuates cardiac fibrosis via targeting connective tissue growth factor

BACKGROUND

Previous studies have shown the role of microRNA (miR)-19 in aging-related heart failure. The present study aimed to verify the effects of miR-19 on cardiac fibrosis and its target.

METHODS

Cardiac fibrosis was induced by myocardial infarction (MI)-induced heart failure and angiotensin (Ang) II-treated rats in vivo, and was induced in Ang II-treated cardiac fibroblasts (CFs) in vitro.

RESULTS

The expression of miR-19 was reduced in the heart tissue of MI and Ang II-treated rats, and Ang II-treated CFs. The impaired cardiac function in rats was repaired after miR-19 administration. The levels of collagen I, collagen III and transforming growth factor-beta (TGF-β) increased in the heart tissue of MI and Ang II-treated rats, and Ang II-treated CFs. These increases were reversed by miR-19 agomiR. Moreover, the bioinformatic analysis and luciferase reporter assays demonstrated that connective tissue growth factor (CTGF) was a direct target of miR-19. MiR-19 treatment inhibited CTGF expression in CFs, while CTGF overexpression inhibited miR-19 agomiR to attenuate the Ang II-induced increases of collagen I and collagen III in CFs. The increases of p-ERK, p-JNK and p-p38 in the CFs induced by Ang II were repressed by miR-19 agomiR.

CONCLUSIONS

Upregulating miR-19 can improve cardiac function and attenuate cardiac fibrosis by inhibiting the CTGF and MAPK pathways.

Positive feedback loop of miR-320 and CD36 regulates the hyperglycemic memory-induced diabetic diastolic cardiac dysfunction

Intensive glycemic control is insufficient for reducing the risk of heart failure among patients with diabetes mellitus (DM). While the "hyperglycemic memory" phenomenon is well documented, little is known about its underlying mechanisms. In this study, a type 1 DM model was established in C57BL/6 mice using streptozotocin (STZ). Leptin receptor-deficient (db/db) mice were used as a model of type 2 DM. A type 9 adeno-associated virus was used to overexpress or knock down miR-320 in vivo. Diastolic dysfunction was observed in the type 1 DM mice with elevated miR-320 expression. However, glycemic control using insulin failed to reverse diastolic dysfunction. miR-320 knockdown protected against STZ-induced diastolic dysfunction. Similar results were observed in the type 2 DM mice. In vitro, we found that miR-320 promoted CD36 expression, which in turn induced further miR-320 expression. CD36 was rapidly induced by hyperglycemia at protein level compared with the much slower induction of miR-320, suggesting a positive feedback loop of CD36/miR-320 with CD36 protein induction as the initial triggering event. In conclusion, in DM-induced cardiac injury, miR-320 and CD36 mutually enhance each other's expression, leading to a positive feedback loop and a sustained hyperlipidemic state in the heart.

Direct Cardiac Epigenetic Reprogramming through Codelivery of 5'Azacytidine and miR-133a Nanoformulation

Direct reprogramming of cardiac fibroblasts to induced cardiomyocytes (iCMs) is a promising approach to cardiac regeneration. However, the low yield of reprogrammed cells and the underlying epigenetic barriers limit its potential. Epigenetic control of gene regulation is a primary factor in maintaining cellular identities. For instance, DNA methylation controls cell differentiation in adults, establishing that epigenetic factors are crucial for sustaining altered gene expression patterns with subsequent rounds of cell division. This study attempts to demonstrate that 5'AZA and miR-133a encapsulated in PLGA-PEI nanocarriers induce direct epigenetic reprogramming of cardiac fibroblasts to cardiomyocyte-like cells. The results present a cardiomyocyte-like phenotype following seven days of the co-delivery of 5'AZA and miR-133a nanoformulation into human cardiac fibroblasts. Further evaluation of the global DNA methylation showed a decreased global 5-methylcytosine (5-medCyd) levels in the 5'AZA and 5'AZA/miR-133a treatment group compared to the untreated group and cells with void nanocarriers. These results suggest that the co-delivery of 5'AZA and miR-133a nanoformulation can induce the direct reprogramming of cardiac fibroblasts to cardiomyocyte-like cells in-vitro, in addition to demonstrating the influence of miR-133a and 5'AZA as epigenetic regulators in dictating cell fate.

Specific microRNAs and heart failure: time for the next step toward application?

A number of microRNAs are involved in the pathophysiological events associated with heart disease. In this review, we discuss miR-21, miR-1, miR-23a, miR-142-5p, miR-126, miR-29, miR-195, and miR-499 because they are most often mentioned as important specific indicators of myocardial hypertrophy and fibrosis leading to heart failure. The clinical use of microRNAs as biomarkers and for therapeutic interventions in cardiovascular diseases appears highly promising. However, there remain many unresolved details regarding their specific actions in distinct pathological phenomena. The introduction of microRNAs into routine practice, as part of the cardiovascular examination panel, will require additional clinically relevant and reliable data. Thus, there remains a need for additional research in this area, as well as the optimization and standardization of laboratory procedures which could significantly shorten the determination time, and make microRNA analysis simpler and more affordable. In this review, we aim to summarize the current knowledge about selected microRNAs related to heart failure, including their potential use in diagnosis, prognosis, and treatment, and options for their laboratory determination.

MicroRNAs: diagnostic, prognostic and therapeutic role in heart failure—a review

Heart failure is a leading cause of morbidity and mortality, with relevant social and economic burden on global healthcare system. Although the development of novel diagnostic tools and the advance in therapies have deeply influenced the diagnosis and treatment of this disease, improving both prognosis and life expectancy of patients, hospitalization is still high, and mortality remains considerable. MicroRNAs are small endogenous RNA molecules that post-transcriptionally regulate gene expression in both physiological and pathological processes. In recent years, microRNA have arisen as attractive therapeutic targets in the treatment of a wide spectrum of pathologies, including heart failure. In cardiac pathology, deregulation of microRNAs expression and function is associated to adverse outcome and heart failure progression. Circulating levels of specific microRNAs have emerged as useful biomarkers for the diagnosis of heart failure or as prognostic indicators. In the present review, we summarize the state of current research on the role of miRNAs as biomarkers for diagnosis and prognosis in patients with heart failure and their use as potential therapeutic targets for this condition.

Mining Potential Drug Targets and Constructing Diagnostic Models for Heart Failure Based on miRNA-mRNA Networks

Heart failure (HF) is a globally prevalent cardiovascular disease, but effective drug targets and diagnostic models are still lacking. This study was designed to investigate effective drug targets and diagnostic models for HF in terms of miRNA targets, hoping to contribute to the understanding and treatment of HF. Using HF miRNA and gene expression profile data from the GEO database, we analyzed differentially expressed miRNAs/gene identification in HF using Limma and predicted miRNA targets by the online TargetScan database. Subsequently, gene set enrichment analysis and annotation were performed using WebGestaltR package. Protein-protein interactions were identified using the STRING database. The proximity of drugs to treat HF was also calculated and predicted for potential target therapeutic drug. In addition, further drug identification was performed by molecular docking. Finally, diagnostic models were constructed based on differential miRNAs. The GEO dataset was used to screen 66 differentially expressed miRNAs, incorporating 56 downregulated miRNAs and 10 upregulated miRNAs. The JAK-STAT signaling pathway, MAPK signaling pathway, p53 signaling pathway, Prolactin signaling pathway, and TGF-beta signaling pathway were enriched, as shown by KEGG enrichment analysis on the target genes. In addition, we found that 83 genes were upregulated and 92 genes were downregulated in HF patients vs. healthy individuals. Based on the inflammation-related score, hypoxia-related score, and energy metabolism-related score, we identified key miRNA-mRNA pairs and constructed an interaction network. Following that, TAP1, which had the highest expression and network connectivity in acute HF with crystal and molecular docking studies, was selected as a key candidate gene in the network. And the compound DB04847 was selected to produce a large number of favorable interactions with TAP1 protein. Finally, we constructed two diagnostic models based on the differential miRNAs hsa-miR-6785-5p and hsa-miR-4443. In conclusion, we identified TAP1, a key candidate gene in the diagnosis and treatment of HF, and determined that compound DB04847 is highly likely to be a potential inhibitor of TAP1. The TAP1 gene was also found to be regulated by hsa-miR-6785-5p and hsa-miR-4443, and a diagnostic model was constructed. This provides a new promising direction to improve the diagnosis, prognosis, and treatment outcome and guide more effective immunotherapy strategies of HF.

Novel diagnostic potential of miR-1 in patients with acute heart failure

Background

A number of circulating micro-ribonucleic acids (miRNAs) have been introduced as convincing predictive determinants in a variety of cardiovascular diseases. This study aimed to evaluate some miRNAs’ diagnostic and prognostic value in patients with acute heart failure (AHF).

Method

Forty-four AHF patients were randomly selected from a tertiary heart center, and 44 healthy participants were included in the control group. Plasma levels of assessed miRNAs, including miR -1, -21, -23, and -423-5-p were measured in both groups. The patients were followed for one year, and several clinical outcomes, including in-hospital mortality, one-year mortality, and the number of readmissions, were recorded.

Results

An overall 88 plasma samples were evaluated. There was no significant difference in terms of demographic characteristics between the AHF and healthy groups. Our findings revealed that mean levels of miR-1, -21, -23, and -423-5-p in AHF patients were significantly higher than in the control group. Although all assessed miRNAs demonstrated high diagnostic potential, the highest sensitivity (77.2%) and specificity (97.7%) is related to miR-1 for the values above 1.22 (p = 0.001, AUC = 0.841; 95%CI, 0.751 to 946). Besides, the levels of miR-21 and -23 were significantly lower in patients with ischemia-induced HF. However, the follow-up data demonstrated no significant association between miRNAs and prognostic outcomes including in-hospital mortality, one-year mortality, and the number of readmissions.

Conclusion

The result of our study demonstrated that miR-1, -21, -23, and -423-5-p can be taken into account as diagnostic aids for AHF. Nevertheless, there was no evidence supporting the efficacy of these miRNAs as prognostic factors in our study.

New Strategies in The Treatment of Advanced Heart Failure in Children and the current consensus of Cairo University Children Hospital heart failure working group

The long-term treatment of congestive heart failure (CHF) in children includes digoxin, diuretics and afterload reduction with angiotensin-converting enzyme (ACE) inhibitors. In spite of the wide use of these drugs being the standard, yet, pediatric heart failure (PHF) continued to be an important cause of morbidity and mortality in childhood. Introduction of new drugs has elevated the level of tolerance of these patients and played a role in delaying their urgent need to have heart transplant or Mechanical circulatory support (MCS). Together with a patient by patient tailored combination of different diuretics. We aim to present and discuss these new drugs and the combinations of regular drugs to reach the best outcome, as well as the consensus of our pediatric heart failure working group in Egypt.

Polyphenols target miRNAs as a therapeutic strategy for diabetic complications

MiRNAs are a large group of non-coding RNAs which participate in different cellular pathways like inflammation and oxidation through transcriptional, post-transcriptional, and epigenetic regulation. In the post-transcriptional regulation, miRNA interacts with the 3'-UTR of mRNAs and prevents their translation. This prevention or dysregulation can be a cause of pathological conditions like diabetic complications. A huge number of studies have revealed the association between miRNAs and diabetic complications, including diabetic nephropathy, cardiomyopathy, neuropathy, retinopathy, and delayed wound healing. To address this issue, recent studies have focused on the use of polyphenols as selective and safe drugs in the treatment of diabetes complications. In this article, we will review the involvement of miRNAs in diabetic complications' occurrence or development. Finally, we will review the latest findings on targeting miRNAs by polyphenols like curcumin, resveratrol, and quercetin for diabetic complications therapy.

Emerging roles of the RNA modifications N6-methyladenosine and adenosine-to-inosine in cardiovascular diseases

Cardiovascular diseases lead the mortality and morbidity disease metrics worldwide. A multitude of chemical base modifications in ribonucleic acids (RNAs) have been linked with key events of cardiovascular diseases and metabolic disorders. Named either RNA epigenetics or epitranscriptomics, the post-transcriptional RNA modifications, their regulatory pathways, components, and downstream effects substantially contribute to the ways our genetic code is interpreted. Here we review the accumulated discoveries to date regarding the roles of the two most common epitranscriptomic modifications, N⁶-methyl-adenosine (m⁶A) and adenosine-to-inosine (A-to-I) editing, in cardiovascular disease.

Differential Expression of microRNAs in Hypertrophied Myocardium and Their Relationship to Late Gadolinium Enhancement, Left Ventricular Hypertrophy and Remodeling in Hypertrophic Cardiomyopathy

Background: Differential expression has been found in a variety of circulating miRNAs in patients with hypertrophic cardiomyopathy (HCM). However, study on myocardial miRNAs is limited and a lot of miRNAs were not studied in previous studies. Methods: Twenty-one HCM patients and four patients who died from non-cardiovascular diseases were prospectively recruited for our study. A total of 26 myocardial tissues were collected, which were stored in liquid nitrogen immediately for miRNA detection using the Agilent Human miRNA Microarray Kit. All HCM patients underwent cardiovascular magnetic resonance (CMR) examination before surgery and cvi42 software was used to analyze cardiac function and myocardial fibrosis. Results: Compared with the control group, the expression of 22 miRNAs was found to be significantly increased in the HCM group, while 46 miRNAs were found to be significantly decreased in the HCM group. The expression levels of hsa-miR-3960 and hsa-miR-652-3p were significantly correlated with left ventricular mass index (r = 0.449 and 0.474, respectively). Meanwhile, Hsa-miR-642a-3p expression was positively correlated to the quantification of late gadolinium enhancement (r = 0.467). Conclusions: Our study found that 68 myocardial miRNAs were significantly increased or decreased in the HCM group. Myocardial miRNA levels could be used as potential biomarkers for LV hypertrophy, fibrosis and remodeling.

New Progress in Early Diagnosis of Atherosclerosis

Coronary atherosclerosis is a potentially chronic circulatory condition that endangers human health. The biological cause underpinning cardiovascular disease is coronary atherosclerosis, and acute cardiovascular events can develop due to thrombosis, platelet aggregation, and unstable atherosclerotic plaque rupture. Coronary atherosclerosis is progressive, and three specific changes appear, with fat spots and stripes, atherosclerosis and thin-walled fiber atherosclerosis, and then complex changes in arteries. The progression and severity of cardiovascular disease are correlated with various levels of calcium accumulation in the coronary artery. The therapy and diagnosis of coronary atherosclerosis benefit from the initial assessment of the size and degree of calcification. This article will discuss the new progress in the early diagnosis of coronary atherosclerosis in terms of three aspects: imaging, gene and protein markers, and trace elements. This study intends to present the latest methods for diagnosing patients with early atherosclerosis through a literature review.

Change of Heart: the Epitranscriptome of Small Non-coding RNAs in Heart Failure

Purpose of Review

Small non-coding RNAs regulate gene expression and are highly implicated in heart failure. Recently, an additional level of post-transcriptional regulation has been identified, referred to as the epitranscriptome, which encompasses the body of post-transcriptional modifications that are placed on RNA molecules. In this review, we summarize the current knowledge on the small non-coding RNA epitranscriptome in heart failure.

Recent Findings

With the rise of new methods to study RNA modifications, epitranscriptome research has begun to take flight. Over the past 3 years, the number of publications on the epitranscriptome in heart failure has significantly increased, and we expect many more highly relevant publications to come out over the next few years.

Summary

Currently, at least six modifications on small non-coding RNAs have been investigated in heart failure-relevant studies, namely N6-adenosine, N5-cytosine and N7-guanosine methylation, 2’-O-ribose-methylation, adenosine-to-inosine editing, and isomiRs. Their potential role in heart failure is discussed.

Research Progress on Transorgan Regulation of the Cardiovascular and Motor System through Cardiogenic Exosomes

The heart is the core organ of the circulatory system. Through the blood circulation system, it has close contact with all tissues and cells in the body. An exosome is an extracellular vesicle enclosed by a phospholipid bilayer. A variety of heart tissue cells can secrete and release exosomes, which transfer RNAs, lipids, proteins, and other biomolecules to adjacent or remote cells, mediate intercellular communication, and regulate the physiological and pathological activities of target cells. Cardiogenic exosomes play an important role in regulating almost all pathological and physiological processes of the heart. In addition, they can also reach distant tissues and organs through the peripheral circulation, exerting profound influence on their functional status. In this paper, the composition and function of cardiogenic exosomes, the factors affecting cardiogenic exosomes and their roles in cardiovascular physiology and pathophysiology are discussed, and the close relationship between cardiovascular system and motor system is innovatively explored from the perspective of exosomes. This study provides a reference for the development and application of exosomes in regenerative medicine and sports health, and also provides a new idea for revealing the close relationship between the heart and other organ systems.

miR-731 modulates the zebrafish heart morphogenesis via targeting Calcineurin/Nfatc3a pathway

BACKGROUND

Zebrafish miR-731 is orthologous of human miR-425, which has been demonstrated to have cardio-protective roles by a variety of mechanisms. The miR-731 morphants show pericardium enlargement, and many DEGs (differentially expressed genes) are enriched in 'Cardiac muscle contraction' and 'Calcium signaling pathway', implying that miR-731 plays a potential role in heart function and development. However，the in vivo physiological role of miR-731 in the heart needs to be fully defined.

METHODS

Zebrafish miR-731 morphants were generated by morpholino knockdown, and miR-731 knockout zebrafish was generated by CRISRP/Cas9. We observed cardiac morphogenesis based on whole-mount in situ hybridization. Furthermore, RNA-seq and qRT-PCR were used to elucidate the molecular mechanism and analyze the gene expression. Double luciferase verification and Western blot were used to verify the target gene.

RESULTS

The depletion of miR-731 in zebrafish embryos caused the deficiency of cardiac development and function, which was associated with reduced heart rate, ventricular enlargement and heart looping disorder. In addition, mechanistic study demonstrated that Calcineurin/Nfatc3a signaling involved in miR-731 depletion induced abnormal cardiac function and developmental defects.

CONCLUSION

MiR-731 regulates cardiac function and morphogenesis through Calcineurin/Nfatc3a signaling.

GENERAL SIGNIFICANCE

Our studies highlight the potential importance of miR-731 in cardiac development.

Circulating miR-489 as a potential new biomarker for idiopathic dilated cardiomyopathy

Objectives:

MicroRNAs (miRNA) are functional RNAs that have emerged as pivotal gene expression regulators in cardiac disease. Although several cardiomyocyte miRNAs have been reported to play roles in heart failure progression among patients with idiopathic dilated cardiomyopathy (DCM), the role of circulating miRNAs has not yet been well-examined.

Methods:

After total RNA extraction from the peripheral blood samples of three control participants and six patients with DCM, miRNA profiling was performed using miRNA arrays. Based on the results of this initial screening, real-time polymerase chain reaction (RT-PCR) was used to perform a quantitative analysis of blood samples from a larger number of matched patients (DCM, n=20; controls, n=5). Finally, the correlations between specific miRNA expression levels and hemodynamic parameters were analyzed.

Results:

A primary screening of 2,565 miRNAs resulted in the identification of nine miRNA candidates. Quantitative RT-PCR results revealed significantly increased miR-489 expression levels in the DCM group. Moreover, there was a significant positive correlation between miR-489 expression level and left ventricular ejection fraction.

Conclusions:

Our results suggest that circulating miR-489 could be a potential noninvasive diagnostic biomarker for DCM. Additionally, the quantification of circulating miR-489 may have value as a potential prognostic marker for patients with DCM.

Determination of microRNAs associated with adverse left ventricular remodeling after myocardial infarction

Increasing evidence indicates that microRNA (miRNA) regulated mechanisms in myocardial healing and ventricular remodeling following acute myocardial infarction (AMI). We aim to comprehensively investigate changes of exosomal miRNA profile during the post-MI period and determine potential miRNAs associated to adverse left ventricular remodeling (ALVR). We prospectively evaluated ST-elevated MI patients with cardiac magnetic resonance imaging at the 2 weeks and 6 months after AMI (n = 10). ALVR was defined as an increase in LV end-diastolic and end-systolic volume > 13%. The blood samples were taken for miRNA measurements at the baseline, 2 and 6 weeks after AMI. In the miRNA profile assessment, 8 miRNAs were identified that were associated ALVR (miR-199a-5p, miR-23b-3p, miR-26b-5p, miR-301a-3p, miR-374a-5p, miR-423-5p, miR-483-5p and miR-652-3p). Three of them (miR-301a-3p, miR-374a-5p and miR-423-5p) differed significantly between patients with and without ALVR during follow-up period and the rest of them during the acute phase of AMI. The detection of these miRNAs, which have different role in various pathways, necessitate future mechanistic studies unravel the complex remodeling process after AMI.

Roles and mechanisms of exosomal non-coding RNAs in human health and diseases

Exosomes play a role as mediators of cell-to-cell communication, thus exhibiting pleiotropic activities to homeostasis regulation. Exosomal non-coding RNAs (ncRNAs), mainly microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are closely related to a variety of biological and functional aspects of human health. When the exosomal ncRNAs undergo tissue-specific changes due to diverse internal or external disorders, they can cause tissue dysfunction, aging, and diseases. In this review, we comprehensively discuss the underlying regulatory mechanisms of exosomes in human diseases. In addition, we explore the current knowledge on the roles of exosomal miRNAs, lncRNAs, and circRNAs in human health and diseases, including cancers, metabolic diseases, neurodegenerative diseases, cardiovascular diseases, autoimmune diseases, and infectious diseases, to determine their potential implication in biomarker identification and therapeutic exploration.

MicroRNA-183-3p Is a Predictor of Worsening Heart Failure in Adult Patients With Transposition of the Great Arteries and a Systemic Right Ventricle

Aim: MicroRNAs (miRNAs) have been shown to play an important role in the progression of heart failure (HF). The aim of our study was to analyze miRNAs in the blood of patients with transposition of the great arteries and a systemic right ventricle (TGA-RV) in order to identify those that predict worsening HF.

Materials and Methods: In 36 patients with TGA-RV, SurePrint™ 8 × 60K Human v21 miRNA microarrays were used to determine the miRNA abundance profiles and compared to 35 age- and gender-matched healthy volunteers (HVs). MiRNAs that were most significantly abundant or best related to worsening HF were further validated by RT-qPCR.

Results: Using miRNA array analysis, a total of 50 down-regulated and 56 up-regulated miRNAs were found to be differentially abundant in TGA-RV patients compared to HVs. Six of these 106 miRNAs were significantly related to worsening HF. After validation by RT-qPCR, four miRNAs turned out to be significantly associated with worsening HF, namely miR-150-5p, miR-1255b-5p, miR-423-3p, and miR-183-3p. In the stepwise multivariable Cox regression analysis, ejection fraction of the systemic RV, high sensitive TNT and miR-183-3p were found to be independent predictors of worsening HF (P = 0.001, P = 0.002, and P = 0.001, respectively).

Conclusions: In patients with TGA-RV, miR-183-3p is an independent predictor of worsening HF and thus may be used as additional biomarker in the risk assessment of these patients.

Generation of microRNA-378a-deficient hiPSC as a novel tool to study its role in human cardiomyocytes

microRNA-378a (miR-378a) is one of the most highly expressed microRNAs in the heart. However, its role in the human cardiac tissue has not been fully understood. It was observed that miR-378a protects cardiomyocytes from hypertrophic growth by regulation of IGF1R and the expression of downstream kinases. Increased levels of miR-378a were reported in the serum of Duchenne muscular dystrophy (DMD) patients and female carriers of DMD gene-associated mutations with developed cardiomyopathy. In order to shed more light on the role of miR-378a in human cardiomyocytes and its potential involvement in DMD-related cardiomyopathy, we generated two human induced pluripotent stem cell (hiPSC) models; one with deletion of miR-378a and the second one with deletion of DMD exon 50 leading to the DMD phenotype. Our results indicate that lack of miR-378a does not influence the pluripotency of hiPSC and their ability to differentiate into cardiomyocytes (hiPSC-CM). miR-378a-deficient hiPSC-CM exhibited, however, significantly bigger size compared to the isogenic control cells, indicating the role of this miRNA in the hypertrophic growth of human cardiomyocytes. In accordance, the level of NFATc3, phosphoAKT, phosphoERK and ERK was higher in these cells compared to the control counterparts. A similar effect was achieved by silencing miR-378a with antagomirs. Of note, the percentage of cells with nuclear localization of NFATc3 was higher in miR-378a-deficient hiPSC-CM. Analysis of electrophysiological properties and Ca²⁺ oscillations revealed the decrease in the spike slope velocity and lower frequency of calcium spikes in miR-378a-deficient hiPSC-CM. Interestingly, the level of miR-378a increased gradually during cardiac differentiation of hiPSC. Of note, it was low until day 15 in differentiating DMD-deficient hiPSC-CM and then rose to a similar level as in the isogenic control counterparts. In summary, our findings confirmed the utility of hiPSC-based models for deciphering the role of miR-378a in the control and diseased human cardiomyocytes.

Circulating miRNAs Are Associated with the Systemic Extent of Atherosclerosis: Novel Observations for miR-27b and miR-146

The mechanisms that regulate the systemic extent of atherosclerosis are not fully understood. We investigated whether the expression of circulating miRNAs is associated with the extent of stable atherosclerosis to a single territory or multiple territories (polyvascular) and with the severity of atherosclerosis in each territory. Ninety-four participants were prospectively recruited and divided into five age- and sex-matched groups: presenting no atherosclerosis, isolated coronary atherosclerosis, coronary and lower extremity atherosclerosis, coronary and carotid atherosclerosis, and atherosclerosis of the coronary, lower extremity, and carotid territories. The expression of six circulating miRNAs with distinct biological roles was assessed. The expression of miR-27b and miR-146 differed across groups (p < 0.05), showing a decrease in the presence of atherosclerosis, particularly in the three territories. miR-27b and miR-146 expression decreased in association with a higher severity of coronary, lower extremity, and carotid atherosclerosis. Polyvascular atherosclerosis involving the three territories was independently associated with a decreased miR-27b and miR-146 expression. Both miRNAs presented an area under the curve of ≥0.75 for predicting polyvascular atherosclerosis involving the three territories. To conclude, miR-27b and miR-146 were associated with the presence of severe polyvascular atherosclerosis and with the atherosclerosis severity in each territory. Both are potential biomarkers of severe systemic atherosclerosis.

Mir-30d Regulates Cardiac Remodeling by Intracellular and Paracrine Signaling

RATIONALE

Previous translational studies implicate plasma extracellular microRNA-30d (miR-30d) as a biomarker in left ventricular remodeling and clinical outcome in heart failure (HF) patients, although precise mechanisms remain obscure.

OBJECTIVE

To investigate the mechanism of miR-30d-mediated cardioprotection in HF.

METHODS AND RESULTS

In rat and mouse models of ischemic HF, we show that miR-30d gain of function (genetic, lentivirus, or agomiR-mediated) improves cardiac function, decreases myocardial fibrosis, and attenuates cardiomyocyte (CM) apoptosis. Genetic or locked nucleic acid-based knock-down of miR-30d expression potentiates pathological left ventricular remodeling, with increased dysfunction, fibrosis, and cardiomyocyte death. RNA sequencing of in vitro miR-30d gain and loss of function, together with bioinformatic prediction and experimental validation in cardiac myocytes and fibroblasts, were used to identify and validate direct targets of miR-30d. miR-30d expression is selectively enriched in cardiomyocytes, induced by hypoxic stress and is acutely protective, targeting MAP4K4 (mitogen-associate protein kinase 4) to ameliorate apoptosis. Moreover, miR-30d is secreted primarily in extracellular vesicles by cardiomyocytes and inhibits fibroblast proliferation and activation by directly targeting integrin α5 in the acute phase via paracrine signaling to cardiac fibroblasts. In the chronic phase of ischemic remodeling, lower expression of miR-30d in the heart and plasma extracellular vesicles is associated with adverse remodeling in rodent models and human subjects and is linked to whole-blood expression of genes implicated in fibrosis and inflammation, consistent with observations in model systems.

CONCLUSIONS

These findings provide the mechanistic underpinning for the cardioprotective association of miR-30d in human HF. More broadly, our findings support an emerging paradigm involving intercellular communication of extracellular vesicle-contained miRNAs (microRNAs) to transregulate distinct signaling pathways across cell types. Functionally validated RNA biomarkers and their signaling networks may warrant further investigation as novel therapeutic targets in HF.

Bortezomib Sustains T Cell Function by Inducing miR-155-Mediated Downregulation of SOCS1 and SHIP1

Suppressive mechanisms operating within T cells are linked to immune dysfunction in the tumor microenvironment. We have previously reported using adoptive T cell immunotherapy models that tumor-bearing mice treated with a regimen of proteasome inhibitor, bortezomib - a dipeptidyl boronate, show increased antitumor lymphocyte effector function and survival. Here, we identify a mechanism for the improved antitumor CD8⁺ T cell function following bortezomib treatment. Intravenous administration of bortezomib at a low dose (1 mg/kg body weight) in wild-type or tumor-bearing mice altered the expression of a number of miRNAs in CD8⁺ T cells. Specifically, the effect of bortezomib was prominent on miR-155 - a key cellular miRNA involved in T cell function. Importantly, bortezomib-induced upregulation of miR-155 was associated with the downregulation of its targets, the suppressor of cytokine signaling 1 (SOCS1) and inositol polyphosphate-5-phosphatase (SHIP1). Genetic and biochemical analysis confirmed a functional link between miR-155 and these targets. Moreover, activated CD8⁺ T cells treated with bortezomib exhibited a significant reduction in programmed cell death-1 (PD-1) expressing SHIP1⁺ phenotype. These data underscore a mechanism of action by which bortezomib induces miR-155-dependent downregulation of SOCS1 and SHIP1 negative regulatory proteins, leading to a suppressed PD-1-mediated T cell exhaustion. Collectively, data provide novel molecular insights into bortezomib-mediated lymphocyte-stimulatory effects that could overcome immunosuppressive actions of tumor on antitumor T cell functions. The findings support the approach that bortezomib combined with other immunotherapies would lead to improved therapeutic outcomes by overcoming T cell exhaustion in the tumor microenvironment.

Circulating microRNA in Heart Failure - Practical Guidebook to Clinical Application

Heart failure (HF) remains a major cause of death and disability worldwide. Currently, B-type natriuretic peptide and N-terminal pro-brain natriuretic peptide are diagnostic biomarkers used in HF. Although very sensitive, they are not specific enough and do not allow the prediction or early diagnosis of HF. Many ongoing studies focus on determining the underlying cause and understanding the mechanisms of HF on the cellular level. MicroRNAs (miRNAs) are non-coding RNAs which control the majority of cellular processes and therefore are considered to have a potential clinical application in HF. In this review, we aim to provide synthesized information about miRNAs associated with ejection fraction, HF etiology, diagnosis, and prognosis, as well as outline therapeutic application of miRNAs in HF. Further, we discuss methodological challenges associated with the analysis of miRNAs and provide recommendations for defining a study population, collecting blood samples, and selecting detection methods to study miRNAs in a reliable and reproducible way. This review is intended to be an accessible tool for clinicians interested in the field of miRNAs and HF.

Noncoding RNAs in Cardiovascular Disease: Current Knowledge, Tools and Technologies for Investigation, and Future Directions: A Scientific Statement From the American Heart Association

Background:

The discovery that much of the non–protein-coding genome is transcribed and plays a diverse functional role in fundamental cellular processes has led to an explosion in the development of tools and technologies to investigate the role of these noncoding RNAs in cardiovascular health. Furthermore, identifying noncoding RNAs for targeted therapeutics to treat cardiovascular disease is an emerging area of research. The purpose of this statement is to review existing literature, offer guidance on tools and technologies currently available to study noncoding RNAs, and identify areas of unmet need.

Methods:

The writing group used systematic literature reviews (including MEDLINE, Web of Science through 2018), expert opinion/statements, analyses of databases and computational tools/algorithms, and review of current clinical trials to provide a broad consensus on the current state of the art in noncoding RNA in cardiovascular disease.

Results:

Significant progress has been made since the initial studies focusing on the role of miRNAs (microRNAs) in cardiovascular development and disease. Notably, recent progress on understanding the role of novel types of noncoding small RNAs such as snoRNAs (small nucleolar RNAs), tRNA (transfer RNA) fragments, and Y-RNAs in cellular processes has revealed a noncanonical function for many of these molecules. Similarly, the identification of long noncoding RNAs that appear to play an important role in cardiovascular disease processes, coupled with the development of tools to characterize their interacting partners, has led to significant mechanistic insight. Finally, recent work has characterized the unique role of extracellular RNAs in mediating intercellular communication and their potential role as biomarkers.

Conclusions:

The rapid expansion of tools and pipelines for isolating, measuring, and annotating these entities suggests that caution in interpreting results is warranted until these methodologies are rigorously validated. Most investigators have focused on investigating the functional role of single RNA entities, but studies suggest complex interaction between different RNA molecules. The use of network approaches and advanced computational tools to understand the interaction of different noncoding RNA species to mediate a particular phenotype may be required to fully comprehend the function of noncoding RNAs in mediating disease phenotypes.

Roles and Functions of Exosomal Non-coding RNAs in Vascular Aging

Aging is a progressive loss of physiological integrity and functionality process which increases susceptibility and mortality to diseases. Vascular aging is a specific type of organic aging. The structure and function changes of endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are the main cause of vascular aging, which could influence the threshold, process, and severity of vascular related diseases. Accumulating evidences demonstrate that exosomes serve as novel intercellular information communicator between cell to cell by delivering variety biologically active cargos, especially exosomal non-coding RNAs (ncRNAs), which are associated with most of aging-related biological and functional disorders. In this review, we will summerize the emerging roles and mechanisms of exosomal ncRNAs in vascular aging and vascular aging related diseases, focusing on the role of exosomal miRNAs and lncRNAs in regulating the functions of ECs and VSMCs. Moreover, the relationship between the ECs and VSMCs linked by exosomes, the potential diagnostic and therapeutic application of exosomes in vascular aging and the clinical evaluation and treatment of vascular aging and vascular aging related diseases will also be discussed.

Cardiac Fibroblasts and Cardiac Fibrosis: Precise Role of Exosomes

Exosomes are a group of extracellular microvesicles that deliver biologically active RNAs, proteins, lipids and other signaling molecules to recipient cells. Classically, exosomes act as a vehicle by which cells or organs communicate with each other to maintain cellular/tissue homeostasis and to respond to pathological stress. Most multicellular systems, including the cardiovascular system, use exosomes for intercellular communication. In heart, endogenous exosomes from cardiac cells or stem cells aid in regulation of cell survival, cell proliferation and cell death; and thus tightly regulate cardiac biology and repair processes. Pathological stimulus in heart alters secretion and molecular composition of exosomes, thus influencing the above processes. The past decade has yielded increasing interest in the role of exosomes in the cardiovascular system and significant contribution of cardiac fibroblast (CF) and mediated cardiac fibrosis in heart failure, in this review we had overviewed the relevant literatures about fibroblast exosomes, its effect in the cardiovascular biology and its impact on cardiovascular disease (CVD). This review briefly describes the communication between fibroblasts and other cardiac cells via exosomes, the influence of such on myocardial fibrosis and remodeling, and the possibilities to use exosomes as biomarkers for acute and chronic heart diseases.

Micro-RNA 150-5p predicts overt heart failure in patients with univentricular hearts

Background

In patients with left heart failure, micro-RNAs (miRNAs) have been shown to be of diagnostic and prognostic value. The present study aims to identify those miRNAs in patients with univentricular heart (UVH) disease that may be associated with overt heart failure.

Methods

A large panel of human miRNA arrays were used to determine miRNA expression profiles in the blood of 48 UVH patients and 32 healthy controls. For further selection, the most abundantly expressed miRNA arrays were related to clinical measures of heart failure and selected miRNAs validated by polymerase chain reaction were used for the prediction of overt heart failure and all-cause mortality.

Results

According to microarray analysis, 50 miRNAs were found to be significantly abundant in UVH patients of which miR-150-5p was best related to heart failure parameters. According to ROC analysis, NT-proBNP levels (AUC 0.940, 95% CI 0.873–1.000; p = 0.001), miR-150-5p (AUC 0.905, 95% CI 0.779–1.000; p = 0.001) and a higher NYHA class ≥ III (AUC 0.893, 95% CI 0.713–1.000; p = 0.002) were the 3 most significant predictors of overt heart failure. Using a combined biomarker model, AUC increased to 0.980 indicating an additive value of miR-150-5p. Moreover, in the multivariate analysis, a higher NYHA class ≥ III (p = 0.005) and miR-150-5p (p = 0.006) turned out to be independent predictors of overt heart failure.

Conclusion

In patients with UVH, miR-150-5p is an independent predictor of overt heart failure and thus may be used in the risk assessment of these patients.

miR-146a Suppresses SUMO1 Expression and Induces Cardiac Dysfunction in Maladaptive Hypertrophy

RATIONALE

Abnormal SUMOylation has emerged as a characteristic of heart failure (HF) pathology. Previously, we found reduced SUMO1 (small ubiquitin-like modifier 1) expression and SERCA2a (sarcoplasmic reticulum Ca²⁺-ATPase) SUMOylation in human and animal HF models. SUMO1 gene delivery or small molecule activation of SUMOylation restored SERCA2a SUMOylation and cardiac function in HF models. Despite the critical role of SUMO1 in HF, the regulatory mechanisms underlying SUMO1 expression are largely unknown.

OBJECTIVE

To examine miR-146a-mediated SUMO1 regulation and its consequent effects on cardiac morphology and function.

METHODS AND RESULTS

In this study, miR-146a was identified as a SUMO1-targeting microRNA in the heart. A strong correlation was observed between miR-146a and SUMO1 expression in failing mouse and human hearts. miR-146a was manipulated in cardiomyocytes through AAV9 (adeno-associated virus serotype 9)-mediated gene delivery, and cardiac morphology and function were analyzed by echocardiography and hemodynamics. Overexpression of miR-146a reduced SUMO1 expression, SERCA2a SUMOylation, and cardiac contractility in vitro and in vivo. The effects of miR-146a inhibition on HF pathophysiology were examined by transducing a tough decoy of miR-146a into mice subjected to transverse aortic constriction. miR-146a inhibition improved cardiac contractile function and normalized SUMO1 expression. The regulatory mechanisms of miR-146a upregulation were elucidated by examining the major miR-146a-producing cell types and transfer mechanisms. Notably, transdifferentiation of fibroblasts triggered miR-146a overexpression and secretion through extracellular vesicles, and the extracellular vesicle-associated miR-146a transfer was identified as the causative mechanism of miR-146a upregulation in failing cardiomyocytes. Finally, extracellular vesicles isolated from failing hearts were shown to contain high levels of miR-146a and exerted negative effects on the SUMO1/SERCA2a signaling axis and hence cardiomyocyte contractility.

CONCLUSIONS

Taken together, our results show that miR-146a is a novel regulator of the SUMOylation machinery in the heart, which can be targeted for therapeutic intervention.

miR-1, miR-499 and miR-208 are sensitive markers to diagnose sudden death due to early acute myocardial infarction

MicroRNAs (miRNAs) are strongly up-regulated under pathological stress and in a wide range of diseases. In recent years, miRNAs are under investigation for their potential use as biomarkers in cardiovascular diseases. We investigate whether specific cardio-miRNAs are overexpressed in heart samples from subjects deceased for acute myocardial infarction (AMI) or sudden cardiac death (SCD), and whether miRNA could help differentiate between them. Forty four cases of death due to cardiovascular disease were selected, respectively, 19 cases categorized as AMI and 25 as SCD. Eighteen cases of traumatic death without pathological cardiac involvement were selected as control. Immunohistochemical investigation was performed for CD15, IL-15, Cx43, MCP-1, tryptase, troponin C and troponin I. Reverse transcription and quantitative real-time PCR were performed for miR-1, miR-133, miR-208 and miR-499. In AMI group, stronger immunoreaction for the CD15, IL-15 and MCP-1 antibodies was detectable compared with SCD and control. Cx43 showed a negative reaction with respect to the other groups. Real-time PCR results showed a down-regulation of all miRNAs in the AMI group compared with SCD and control. The selected miRNAs presented high accuracy in discriminating SCD from AMI (miR-1 and miR-499) and AMI from control (miR-208) representing a potential aid for both clinicians and pathologists for differential diagnosis.

MicroRNAs Associated With Reverse Left Ventricular Remodeling in Humans Identify Pathways of Heart Failure Progression

BACKGROUND

Plasma extracellular RNAs have recently garnered interest as biomarkers in heart failure (HF). Most studies in HF focus on single extracellular RNAs related to phenotypes and outcomes, and few describe their functional roles. We hypothesized that clusters of plasma microRNAs (miRNAs) associated with left ventricular (LV) remodeling in human HF would identify novel subsets of genes involved in HF in animal models.

METHODS AND RESULTS

We prospectively measured circulating miRNAs in 64 patients with systolic HF (mean age, 64.8 years; 91% men; median LV ejection fraction, 26%) with serial echocardiography (10 months apart) during medical therapy. We defined LV reverse remodeling as a 15% reduction in LV end-systolic volume index. Using principal components analysis, we identified a component associated with LV reverse remodeling (odds ratio=3.99; P=0.01) that provided risk discrimination for LV reverse remodeling superior to a clinical model (C statistic, 0.58 for a clinical model versus 0.71 for RNA-based model). Using network bioinformatics, we uncovered genes not previously widely described in HF regulated simultaneously by >2 miRNAs. We observed increased myocardial expression of these miRNAs during HF development in animals, with downregulation of target gene expression, suggesting coordinate miRNA-mRNA regulation. Target mRNAs were involved in autophagy, metabolism, and inflammation.

CONCLUSIONS

Plasma miRNAs associated with LV reverse remodeling in humans are dysregulated in animal HF and target clusters of genes involved in mechanisms implicated in HF. A translational approach integrating human HF, bioinformatics, and model systems may uncover novel pathways involved in HF.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00351390.

Regulation of microRNAs by molecular hydrogen contributes to the prevention of radiation-induced damage in the rat myocardium

microRNAs (miRNAs) constitute a large class of post-transcriptional regulators of gene expression. It has been estimated that miRNAs regulate up to 30% of the protein-coding genes in humans. They are implicated in many physiological and pathological processes, including those involved in radiation-induced heart damage. Biomedical studies indicate that molecular hydrogen has potential as a radioprotective agent due to its antioxidant, anti-inflammatory, and signal-modulating effects. However, the impact of molecular hydrogen on the expression of miRNAs in the heart after irradiation has not been investigated. This study aimed to explore the involvement of miRNA-1, -15b, and -21 in the protective action of molecular hydrogen on rat myocardium damaged by irradiation. The results showed that the levels of malondialdehyde (MDA) and tumor necrosis factor alpha (TNF-α) increased in the rat myocardium after irradiation. Treatment with molecular hydrogen-rich water (HRW) reduced these values to the level of non-irradiated controls. miRNA-1 is known to be involved in cardiac hypertrophy, and was significantly decreased in the rat myocardium after irradiation. Application of HRW attenuated this decrease in all evaluated time periods. miRNA-15b is considered to be anti-fibrotic, anti-hypertrophic, and anti-oxidative. Irradiation downregulated miRNA-15b, whereas administration of HRW restored these values. miRNA-21 is connected with cardiac fibrosis. We observed significant increase in miRNA-21 expression in the irradiated rat hearts. Molecular hydrogen lowered myocardial miRNA-21 levels after irradiation. This study revealed for the first time that the protective effects of molecular hydrogen on irradiation-induced heart damage may be mediated by regulating miRNA-1, -15b, and -21.

miRNA-378a as a key regulator of cardiovascular health following engineered nanomaterial inhalation exposure

Nano-titanium dioxide (nano-TiO₂), though one of the most utilized and produced engineered nanomaterials (ENMs), diminishes cardiovascular function through dysregulation of metabolism and mitochondrial bioenergetics following inhalation exposure. The molecular mechanisms governing this cardiac dysfunction remain largely unknown. The purpose of this study was to elucidate molecular mediators that connect nano-TiO₂ exposure with impaired cardiac function. Specifically, we were interested in the role of microRNA (miRNA) expression in the resulting dysfunction. Not only are miRNA global regulators of gene expression, but also miRNA-based therapeutics provide a realistic treatment modality. Wild type and MiRNA-378a knockout mice were exposed to nano-TiO₂ with an aerodynamic diameter of 182 ± 1.70 nm and a mass concentration of 11.09 mg/m³ for 4 h. Cardiac function, utilizing the Vevo 2100 Imaging System, electron transport chain complex activities, and mitochondrial respiration assessed cardiac and mitochondrial function. Immunoblotting and qPCR examined molecular targets of miRNA-378a. MiRNA-378a-3p expression was increased 48 h post inhalation exposure to nano-TiO₂. Knockout of miRNA-378a preserved cardiac function following exposure as revealed by preserved E/A ratio and E/SR ratio. In knockout animals, complex I, III, and IV activities (∼2- to 6-fold) and fatty acid respiration (∼5-fold) were significantly increased. MiRNA-378a regulated proteins involved in mitochondrial fusion, transcription, and fatty acid metabolism. MiRNA-378a-3p acts as a negative regulator of mitochondrial metabolic and biogenesis pathways. MiRNA-378a knockout animals provide a protective effect against nano-TiO₂ inhalation exposure by altering mitochondrial structure and function. This is the first study to manipulate a miRNA to attenuate the effects of ENM exposure.

microRNA-665 silencing improves cardiac function in rats with heart failure through activation of the cAMP signaling pathway

Heart failure (HF) is a disease with high mortality and morbidity rate. Previous studies have shown that microRNAs (miRNAs) may be implicated in the pathogenesis of HF, potentially being able to improve the cardiac function in an HF rat model. The present study was designed to define the role of miR-665 in the cardiac function of the HF rats. Following the establishm;ent of the rat models of HF, the functional role miR-665 in HF was determined using an ectopic expression and knockdown experiments. The cardiac function was evaluated with the determination of ventricular mass index and hemodynamic parameters. Terminal deoxynucleotidyl transferase dUTP nick end labeling staining was performed, with the apoptosis of cardiac cells detected in the process. The expression of miR-665, glucagon-like peptide 1 receptor (GLP1R), cyclic adenosine monophosphate (cAMP) signaling pathway-related, and apoptosis-related genes was examined. Enzyme-linked immunosorbent assay was conducted to determine the levels of inflammation-related genes. Initially, the upregulation of miR-665, downregulation of GLP1R, and inactivation of cAMP signaling pathway were observed in HF rats. GLP1R was a target of miR-665. Forced expression of miR-665 promoted cell apoptosis and inhibited GLP1R and the cAMP signaling pathway. In addition, miR-665 overexpression has been known to impair cardiac function, promote inflammatory response while elevating malondialdehyde and superoxide dismutase levels, and decreasing mitochondrial respiratory chain enzyme activities. Furthermore, we also observed that the effects of miR-665 inhibition had been reversed when the cAMP signaling pathway was also inhibited. This study demonstrates that miR-665 inhibition can stabilize the cardiac function of HF rats via the cAMP signaling pathway via upregulation of the GLP1R.

AntagomiR-103 and -107 Treatment Affects Cardiac Function and Metabolism

MicroRNA-103/107 regulate systemic glucose metabolism and insulin sensitivity. For this reason, inhibitory strategies for these microRNAs are currently being tested in clinical trials. Given the high metabolic demands of the heart and the abundant cardiac expression of miR-103/107, we questioned whether antagomiR-mediated inhibition of miR-103/107 in C57BL/6J mice impacts on cardiac function. Notably, fractional shortening decreased after 6 weeks of antagomiR-103 and -107 treatment. This was paralleled by a prolonged systolic radial and circumferential time to peak and by a decreased global strain rate. Histology and electron microscopy showed reduced cardiomyocyte area and decreased mitochondrial volume and mitochondrial cristae density following antagomiR-103 and -107. In line, antagomiR-103 and -107 treatment decreased mitochondrial OXPHOS complexes’ protein levels compared to scrambled, as assessed by mass spectrometry-based label-free quantitative proteomics. MiR-103/107 inhibition in primary cardiomyocytes did not affect glycolysis rates, but it decreased mitochondrial reserve capacity, reduced mitochondrial membrane potential, and altered mitochondrial network morphology, as assessed by live-cell imaging. Our data indicate that antagomiR-103 and -107 decrease cardiac function, cardiomyocyte size, and mitochondrial oxidative capacity in the absence of pathological stimuli. These data raise concern about the possible cardiac implications of the systemic use of antagomiR-103 and -107 in the clinical setting, and careful cardiac phenotyping within ongoing trials is highly recommended.