Identifying circulating microRNAs as biomarkers of cardiovascular disease: a systematic review

Machine learning: a new era for cardiovascular pregnancy physiology and cardio-obstetrics research

The maternal cardiovascular system undergoes functional and structural adaptations during pregnancy and postpartum to support increased metabolic demands of offspring and placental growth, labor, and delivery, as well as recovery from childbirth. Thus, pregnancy imposes physiological stress upon the maternal cardiovascular system, and in the absence of an appropriate response it imparts potential risks for cardiovascular complications and adverse outcomes. The proportion of pregnancy-related maternal deaths from cardiovascular events has been steadily increasing, contributing to high rates of maternal mortality. Despite advances in cardiovascular physiology research, there is still no comprehensive understanding of maternal cardiovascular adaptations in healthy pregnancies. Furthermore, current approaches for the prognosis of cardiovascular complications during pregnancy are limited. Machine learning (ML) offers new and effective tools for investigating mechanisms involved in pregnancy-related cardiovascular complications as well as the development of potential therapies. The main goal of this review is to summarize existing research that uses ML to understand mechanisms of cardiovascular physiology during pregnancy and develop prediction models for clinical application in pregnant patients. We also provide an overview of ML platforms that can be used to comprehensively understand cardiovascular adaptations to pregnancy and discuss the interpretability of ML outcomes, the consequences of model bias, and the importance of ethical consideration in ML use.

A Review of MicroRNAs and lncRNAs in Atherosclerosis as Well as Some Major Inflammatory Conditions Affecting Atherosclerosis

It is generally accepted that atherosclerosis is a chronic inflammatory disease. The link between atherosclerosis and other inflammatory diseases such as psoriasis, type 2 diabetes mellitus (T2DM), and rheumatoid arthritis (RA) via metabolic, inflammatory, and immunoregulatory pathways is well established. The aim of our review was to summarize the associations between selected microRNAs (miRs) and long non-coding RNAs (lncRNAs) and atherosclerosis, psoriasis, T2DM, and RA. We reviewed the role of miR-146a, miR-210, miR-143, miR-223, miR-126, miR-21, miR-155, miR-145, miR-200, miR-133, miR-135, miR-221, miR-424, let-7, lncRNA-H19, lncRNA-MEG3, lncRNA-UCA1, and lncRNA-XIST in atherosclerosis and psoriasis, T2DM, and RA. Extracellular vesicles (EVs) are a method of intracellular signal transduction. Their function depends on surface expression, cargo, and the cell from which they originate. The majority of the studies that investigated lncRNAs and some miRs had relatively small sample sizes, which limits the generalizability of their findings and indicates the need for more research. Based on the studies reviewed, miR-146a, miR-155, miR-145, miR-200, miR-133, and lncRNA-H19 are the most promising potential biomarkers and, possibly, therapeutic targets for atherosclerosis as well as T2DM, RA, and psoriasis.

A combined circulating microRNA panel predicts the risk of vascular calcification in community-dwelling older adults with age strata differences

BACKGROUND

Older adults have a higher risk of developing vascular calcification (VC). Circulating miRNAs can be potential risk indicators. However, prior studies used single miRNA mostly, whereas miRNA panels were rarely evaluated. We aimed to examine whether a miRNA panel outperformed each miRNA alone, and analyzed whether advanced age affected VC risk predictive performance offered by the miRNA panel.

METHODS

We prospectively enrolled older adults (age ≥65 years) during their annual health checkup in 2017, and examined their VC severity followed by analyzing sera for VC regulatory miRNAs (miR-125b-5p, miR-125b-3p, and miR-378a-3p). We used multiple regression analyses to determine associations between each miRNA or a 3-combind panel and VC risk, followed by area under the receiver-operating-characteristics curve (AUROC) analysis. Participants were further divided to those of 65-75 and ≥75 years for comparison.

RESULTS

From 199 older adults screened, 169 (median age, 73.3 years) with available calcification assessment were analyzed, among whom 74.6 % having VC. Those with VC had significantly lower circulating miR-125b-5p, miR-125b-3p, and miR-378a-3p levels than those without. Regression analyses showed that the 3-combined miRNA panel exhibited significant associations with VC risk, with significantly higher AUROC than those of models based on individual miRNA. Importantly, in those ≥75 years, the miRNA-predicted risk of VC was more prominent than that in the 65-75 years group.

CONCLUSION

A miRNA panel for VC risk prediction might outperform individual miRNA alone in older adults, and advanced age modified the association between circulating miRNAs and the risk of VC.

Identification of microRNA biomarkers simultaneously expressed in circulating extracellular vesicles and atherosclerotic plaques

Background

Atherosclerosis is a widespread disorder of the cardiovascular system. The early detection of plaques by circulating biomarkers is highly clinically relevant to prevent the occurrence of major complications such as stroke or heart attacks. It is known that extracellular vesicles (EVs) are important in intercellular communication in atherosclerotic disorders and carry many components of their cells of origin, including microRNAs (miRNAs). In this study, we test the assumption that miRNAs present in material acquired from plaques in patients undergoing surgery for atherosclerotic carotid artery stenosis are also expressed in circulating EVs obtained from the identical patients. This would allow the adoption of a liquid biopsy approach for the detection of plaques.

Methods

We studied 22 surgical patients with atherosclerotic carotid arterial stenosis and 28 healthy controls. EVs were isolated from serum by precipitation. miRNA expression profiles of serum-derived EVs were obtained by small RNA sequencing and in plaque material simultaneously acquired from patients. A comparative analysis was performed to identify circulating atherosclerosis-associated miRNAs that are also detectable in plaques.

Results

Seven miRNAs were found to be differentially regulated in patient serum compared with the serum of healthy controls. Of these, miR-193b-5p, miR-193a-5p, and miR-125a-3p were significantly upregulated in patients compared with that in healthy controls and present in both, circulating EVs and plaque material. An overrepresentation analysis of experimentally validated mRNA targets revealed an increased regulation of inflammation and vascular growth factors, key players in atherosclerosis and plaque formation.

Conclusion

Our findings suggest that circulating EVs reflect plaque development in patients with symptomatic carotid artery stenosis, which can serve as biomarker candidates for detecting the presence of atherosclerotic plaques.

Discriminatory power of a circulating multi-noncoding RNA panel in acute coronary syndrome subtypes: Towards precision detection

BACKGROUND

Acute Coronary Syndrome (ACS) stands as a significant contributor to cardiovascular mortality, necessitating improved diagnostic tools for early detection and tailored therapeutic interventions. Current diagnostic modalities, exhibit limitations in sensitivity and specificity, urging the quest for novel biomarkers to enhance discrimination of the different stages of ACS including unstable angina, Non-ST-segment Elevation Myocardial Infarction (NSTEMI), and ST-segment Elevation Myocardial Infarction (STEMI).

METHODS

This study investigated the potential of a plasma-circulating multi-noncoding RNA (ncRNA) panel, comprising four miRNAs (miR-182-5p, miR-23a-3p, miR-146a-5p, and miR-183-5p) and three lncRNAs (SNHG15, SNHG5, and RMRP), selected based on their intricate involvement in ACS pathogenesis and signaling pathways regulating post-myocardial infarction (MI) processes. The differential expression of these ncRNAs was validated in sera of ACS patients and healthy controls via real-time polymerase chain reaction (RT-PCR).

RESULTS

Analysis revealed a marked upregulation of the multi-ncRNAs panel in ACS patients. Notably, miRNA-182-5p and lncRNA-RMRP exhibited exceptional discriminatory power, indicated by the high area under the curve (AUC) values (0.990 and 0.980, respectively). Importantly, this panel displayed superior efficacy in discriminating between STEMI and NSTEMI, outperforming conventional biomarkers like creatine kinase-MB and cardiac troponins. Additionally, the four miRNAs and lncRNA RMRP showcased remarkable proficiency in distinguishing between STEMI and unstable angina.

CONCLUSION

The findings underscore the promising potential of the multi-ncRNA panel as a robust tool for early ACS detection, and precise differentiation among ACS subtypes, and as a potential therapeutic target.

microRNAs and their therapeutic strategy in phase I and phase II clinical trials

miRNAs play a crucial therapeutic role in diseases such as cancer, diabetes and viral infections, with around 1900 identified in the human genome. Some have progressed to clinical trials, and miRNA mimics and miRNA inhibitors are pivotal therapeutic molecules undergoing evaluation. The review delves into various miRNA-associated clinical trials, emphasizing their precision in targeting specific genes, modulating disease pathways and diagnostic potential. This underscores the importance of miRNA therapy, foreseeing innovations in precision medicine techniques for diverse diseases. The future envisions improved delivery systems addressing challenges like immunogenicity and digestion, while a comprehensive miRNA-based omics database could guide the development of tailored antisense miRNAs, further advancing precision medicine strategies.

miR-133a-3p/TRPM4 axis improves palmitic acid induced vascular endothelial injury

Background: Vascular endothelial injury is a contributing factor to the development of atherosclerosis and the resulting cardiovascular diseases. One particular factor involved in endothelial cell apoptosis and atherosclerosis is palmitic acid (PA), which is a long-chain saturated fatty acid. In addition, transient receptor potential melastatin 4 (TRPM4), a non-selective cation channel, plays a significant role in endothelial dysfunction caused by various factors related to cardiovascular diseases. Despite this, the specific role and mechanisms of TRPM4 in atherosclerosis have not been fully understood. Methods: The protein and mRNA expressions of TRPM4, apoptosis - and inflammation-related factors were measured after PA treatment. The effect of TRPM4 knockout on the protein and mRNA expression of apoptosis and inflammation-related factors was detected. The changes of intracellular Ca2+, mitochondrial membrane potential, and reactive oxygen species were detected by Fluo-4 AM, JC-1, and DCFH-DA probes, respectively. To confirm the binding of miR-133a-3p to TRPM4, a dual luciferase reporter gene assay was conducted. Finally, the effects of miR-133a-3p and TRPM4 on intracellular Ca2+, mitochondrial membrane potential, and reactive oxygen species were examined. Results: Following PA treatment, the expression of TRPM4 increases, leading to calcium overload in endothelial cells. This calcium influx causes the assemblage of Bcl-2, resulting in the opening of mitochondrial calcium channels and mitochondrial damage, ultimately triggering apoptosis. Throughout this process, the mRNA and protein levels of IL-1β, ICAM-1, and VCAM1 significantly increase. Database screenings and luciferase assays have shown that miR-133a-3p preferentially binds to the 3'UTR region of TRPM4 mRNA, suppressing TRPM4 expression. During PA-induced endothelial injury, miR-133a-3p is significantly decreased, but overexpression of miR-133a-3p can attenuate the progression of endothelial injury. On the other hand, overexpression of TRPM4 counteracts the aforementioned changes. Conclusion: TRPM4 participates in vascular endothelial injury caused by PA. Therefore, targeting TRPM4 or miR-133a-3p may offer a novel pharmacological approach to preventing endothelial injury.

Circulating isomiRs May Be Superior Biomarkers Compared to Their Corresponding miRNAs: A Pilot Biomarker Study of Using isomiR-Ome to Detect Coronary Calcium-Based Cardiovascular Risk in Patients with NAFLD

Circulating miRNAs are increasingly being considered as biomarkers in various medical contexts, but the value of analyzing isomiRs (isoforms of canonical miRNA sequences) has not frequently been assessed. Here we hypothesize that an in-depth analysis of the full circulating miRNA landscape could identify specific isomiRs that are stronger biomarkers, compared to their corresponding miRNA, for identifying increased CV risk in patients with non-alcoholic fatty liver disease (NAFLD)-a clinical unmet need. Plasma miRNAs were sequenced with next-generation sequencing (NGS). Liver fat content was measured with magnetic-resonance spectrometry (MRS); CV risk was determined, beyond using traditional biomarkers, by a CT-based measurement of coronary artery calcium (CAC) score and the calculation of a CAC score-based CV-risk percentile (CAC-CV%). This pilot study included n = 13 patients, age > 45 years, with an MRS-measured liver fat content of ≥5% (wt/wt), and free of overt CVD. NGS identified 1103 miRNAs and 404,022 different isomiRs, of which 280 (25%) and 1418 (0.35%), respectively, passed an abundance threshold. Eighteen (sixteen/two) circulating miRNAs correlated positively/negatively, respectively, with CAC-CV%, nine of which also significantly discriminated between high/low CV risk through ROC-AUC analysis. IsomiR-ome analyses uncovered 67 isomiRs highly correlated (R ≥ 0.55) with CAC-CV%. Specific isomiRs of miRNAs 101-3p, 144-3p, 421, and 484 exhibited stronger associations with CAC-CV% compared to their corresponding miRNA. Additionally, while miRNAs 140-3p, 223-3p, 30e-5p, and 342-3p did not correlate with CAC-CV%, specific isomiRs with altered seed sequences exhibited a strong correlation with coronary atherosclerosis burden. Their predicted isomiRs-specific targets were uniquely enriched (compared to their canonical miRNA sequence) in CV Disease (CVD)-related pathways. Two of the isomiRs exhibited discriminative ROC-AUC, and another two showed a correlation with reverse cholesterol transport from cholesterol-loaded macrophages to ApoB-depleted plasma. In summary, we propose a pipeline for exploring circulating isomiR-ome as an approach to uncover novel and strong CVD biomarkers.

The miRNA variants MIR196A2 (rs11614913) and MIR423 (rs6505162) contribute to an increase in the risk of myocardial infarction

INTRODUCTION

MicroRNAs (miRNAs) are small, single-stranded RNA molecules that negatively regulate gene expression and play a key role in the pathogenesis of human diseases. Recent studies have suggested that miRNAs contribute to cardiovascular diseases (CVDs). However, the association between single-nucleotide polymorphisms (SNPs) in miRNAs and myocardial infarction (MI) remains in infancy.

AIM

The current study was designed to find out the association of SNPs in MIR196A2 and MIR423 (rs11614913 and rs6505162, respectively).

METHODS

Using Tetra-Primer Amplification Refractory Mutation System-Polymerase Chain Reaction (T-ARMS PCR) in 400 cases (MI patients) and 336 healthy controls. Using different inheritance models (co-dominant, homozygous dominant, homozygous recessive, and additive models), the association of these SNPs was genotyped with MI risk.

RESULTS

For variant rs11614913, significant distribution of the genotypes among the cases and controls was determined by co-dominant [χ2  = 29.19, 2; p value < 0.0001], dominant (C/C vs. C/T + T/T) [OR = 0.45 (0.34 to 0.61); p < 0.0001], recessive (T/T vs. C/T + C/C) [OR = 1.009 (0.63 to 1.63); p-value p value > 0.999], and additive models [OR = 0.65 (0.52 to 0.80); p value = 0.0001]. Similarly, a significant association of rs6505162 was determined by co-dominant [χ2  = 24.29, 2; p value < 0.0001], dominant (C/C vs. A/C+ A/A) [OR = 0.44 (0.32 to 0.61); p value < 0.0001], recessive (A/A vs. A/C + C/C) [OR = 1.29 (0.85 to 1.98); p value = 0.28], and additive models [OR = 0.65 (0.52 to 0.81); p value = 0.0001].

CONCLUSION

Therefore, the current study showed that both variants rs11614913 and rs6505162 are significantly associated with MI in the Pakistani population.

Mechanisms and Optimization Strategies of Paracrine Exosomes from Mesenchymal Stem Cells in Ischemic Heart Disease

The morbidity and mortality of myocardial infarction (MI) are increasing worldwide. Mesenchymal stem cells (MSCs) are multipotent stem cells with self-renewal and differentiation capabilities that are essential in tissue healing and regenerative medicine. However, the low implantation and survival rates of transplanted cells hinder the widespread clinical use of stem cells. Exosomes are naturally occurring nanovesicles that are secreted by cells and promote the repair of cardiac function by transporting noncoding RNA and protein. In recent years, MSC-derived exosomes have been promising cell-free treatment tools for improving cardiac function and reversing cardiac remodeling. This review describes the biological properties and therapeutic potential of exosomes and summarizes some engineering approaches for exosomes optimization to enhance the targeting and therapeutic efficacy of exosomes in MI.

MiRNA-Responsive CRISPR-Cas System via a DNA Regulator

Clustered regularly interspaced short palindromic repeats (CRISPR)- CRISPR-associated protein 9 (Cas9) genome editing technology is widely used for gene editing because it provides versatility in genetic manipulation. Several methods for regulating CRISPR activity already exist for accurate editing, but these require complex engineering. Thus, a simple and convenient regulatory system is required. In this study, we devised a CRISPR activation system using a DNA regulator that can be activated by miRNAs. The designed regulator was divided into two parts. The inhibition component consisted of the protospacer-adjacent motif (PAM) and seed sequence, which are important for Cas9 target recognition and bind to the ribonucleoprotein (RNP) complex for inhibition. The miRNA recognition component has a single-stranded toehold DNA for target miRNA binding and a partial double-stranded DNA complementary to the remaining miRNA sequence. In the presence of target miRNAs, the structure of the regulator is disrupted by the miRNAs, leading to its dissociation from the RNP complex and subsequent restoration of CRISPR activity. This method is easy to design and can be applied to various miRNAs via simple sequence manipulation. Therefore, this strategy provides a general platform for controlled genome editing.

Clinical relevance of circulating non-coding RNAs in metabolic diseases: Emphasis on obesity, diabetes, cardiovascular diseases and metabolic syndrome

Non-coding RNAs (ncRNAs) participate in the regulation of several cellular processes including transcription, RNA processing and genome rearrangement. The aberrant expression of ncRNAs is associated with several pathological conditions. In this review, we focused on recent information to elucidate the role of various regulatory ncRNAs i.e., micro RNAs (miRNAs), circular RNAs (circRNAs) and long-chain non-coding RNAs (lncRNAs), in metabolic diseases, e.g., obesity, diabetes mellitus (DM), cardiovascular diseases (CVD) and metabolic syndrome (MetS). The mechanisms by which ncRNAs participated in disease pathophysiology were also highlighted. miRNAs regulate the expression of genes at transcriptional and translational levels. circRNAs modulate the regulation of gene expression via miRNA sponging activity, interacting with RNA binding protein and polymerase II transcription regulation. lncRNAs regulate the expression of genes by acting as a protein decoy, miRNA sponging, miRNA host gene, binding to miRNA response elements (MRE) and the recruitment of transcriptional element or chromatin modifiers. We examined the role of ncRNAs in the disease pathogenesis and their potential role as molecular markers for diagnosis, prognosis and therapeutic targets. We showed the involvement of ncRNAs in the onset of obesity and its progression to MetS and CVD. miRNA-192, miRNA-122, and miRNA-221 were dysregulated in all these metabolic diseases. Other ncRNAs, implicated in at least three diseases include miRNA-15a, miRNA-26, miRNA-27a, miRNA-320, and miRNA-375. Dysregulation of ncRNAs increased the risk of development of DM and MetS and its progression to CVD in obese individuals. Hence, these molecules are potential targets to arrest or delay the progression of metabolic diseases.

The clinical value of hsa-miR-190b-5p in peripheral blood of pediatric β-thalassemia and its regulation on BCL11A expression

BACKGROUND

The B cell CLL/lymphoma 11A (BCL11A) is a key regulator of hemoglobin switching in β-thalassemia (β-thal). Previous study has suggested that dysregulated microRNAs are involved in the regulation of BCL11A expression. The aim of this study was to investigate the clinical value of hsa-miR-190b-5p in β-thal, and to confirm the regulatory effect of hsa-miR-190b-5p on BCL11A expression.

METHODS

The peripheral blood of 25 pediatric β-thal patients and 25 healthy controls were selected, and qRT-PCR was used to analyze the levels of hsa-miR-190b-5p and BCL11A mRNA. The relationship between hsa-miR-190b-5p expression and hematological parameters was assessed by Pearson's correlation test. The diagnostic power of hsa-miR-190b-5p was evaluated by ROC curves analysis. The direct integration between hsa-miR-190b-5p and BCL11A 3'-UTR was confirmed by luciferase reporter assay.

RESULTS

Hsa-miR-190b-5p expression in pediatric β-thal was upregulated, and negatively correlated with the MCH and HbA levels, but positively correlated with the HbF level. Hsa-miR-190b-5p showed a good diagnostic capability for pediatric β-thal equivalent to that of HbA2 (AUC: 0.760 vs. 0.758). Moreover, the levels of BCL11A mRNA in pediatric β-thal were decreased, and hsa-miR-190b-5p had a negative correlation with BCL11A mRNA expression (r = -0.403). BCL11A was a target gene of hsa-miR-190b-5p. The mRNA and protein levels of BCL11A were diminished by introduction of hsa-miR-190b-5p, whereas its expression was upregulated by knockdown of hsa-miR-190b-5p.

CONCLUSIONS

Hsa-miR-190b-5p expression was upregulated in pediatric β-thal and might be an effective diagnostic biomarker. BCL11A was negatively regulated by hsa-miR-190b-5p, which might provide new target for the treatment of pediatric β-thal.

CircMACF1 alleviates myocardial fibrosis after acute myocardial infarction by suppressing cardiac fibroblast activation via the miR-16-5p/SMAD7 axis

Circular RNAs (circRNAs) played a pivotal role in myocardial fibrosis after acute myocardial infarction (AMI). The activation of cardiac fibroblasts (CFs) and accumulation of extracellular matrix are the main characteristics of myocardial fibrosis. In our research, we aimed to elucidate the functional roles of circMACF1 in CF activation after AMI as well as the underlying mechanism. Human CFs were activated by TGF-β1 treatment. qPCR and western blotting were performed to investigate gene and protein expression. CCK-8 and transwell assays were carried out to measure cell proliferation, and migration. Immunofluorescence was used to investigate α-SMA level. The interaction between miR-16-5p and circMACF1 or SMAD7 was revealed by RIP or dual luciferase reporter gene assays. CircMACF1 and SMAD7 were repressed in AMI patients and CFs treated with TGF-β1, and miR-16-5p was increased. In addition, circMACF1 was resistant to RNase R and abundantly expressed in the cytoplasm. Overexpression of circMACF1 inhibited cell proliferation and migration and reduced the expression levels of fibrosis-related proteins, including Collagen I, Collagen III, and α-SMA. Furthermore, circMCAF1 could directly bind to miR-16-5p, and SMAD7 was a target gene of miR-16-5p. Knockdown of miR-16-5p suppressed the activation, proliferation, and migration of TGF-β1-treated CFs, but silencing circMACF1 or SMAD7 partially reversed this phenomenon. CircMACF1 attenuated the TGF-β1-induced activation, proliferation and migration of CFs via the miR-16-5p/SMAD7 signaling pathway, indicating that circMACF1 might be a new therapeutic target for AMI.

Triple ligation-based formation of a G-quadruplex for simultaneous detection of multiple miRNAs

The simultaneous detection of multiple microRNAs (miRNA) is of great necessity but has not been extensively studied. This prompted our study, which involved the development of a triple ligation-based system for detecting three miRNAs at the same time. We designed a multi-ligation-padlock (MLP) probe that consists of three parts, each of which is complementary to two different miRNAs at the same time. In the presence of all three miRNAs, the probe becomes circularized, but in the absence of even one target, the probe remains linear. The first part of the MLP probe (MLP1) contains a T7 promoter part that can initiate RNA synthesis for any given target condition. However, it also includes a G-quadruplex complementary segment, which can only form a parallel RNA G-quadruplex through rolling circle transcription by the circularized template in the presence of all three targets. In this case, the application of our parallel G-quadruplex sensing fluorescent probe lutidine DESA (LutD) produces a strong signal. However, in the absence of any one of the targets, the RNA G-quadruplex cannot be formed and ultimately the LutD probe does not generate any signal. This difference in the signal intensity represents the presence or absence of all the target miRNAs. With our system, we were able to detect miRNA 21 at levels as low as 1.13 fM, miRNA 146a as low as 1.37 fM, and miRNA 25b as low as 1.51 fM within 45 minutes, confirming that our novel system can selectively and sensitively diagnose triple miRNAs.

Recent Advances of Using Exosomes as Diagnostic Markers and Targeting Carriers for Cardiovascular Disease

Cardiovascular diseases (CVDs) are the leading cause of human death worldwide. Exosomes act as endogenous biological vectors; they possess advantages of low immunogenicity and low safety risks, also providing tissue selectivity, including the inherent targeting the to heart. Therefore, exosomes not only have been applied as biomarkers for diagnosis and therapeutic outcome confirmation but also showed potential as drug carriers for cardiovascular targeting delivery. This review aims to summarize the progress and challenges of exosomes as novel biomarkers, especially many novel exosomal noncoding RNAs (ncRNAs), and also provides an overview of the improved targeting functions of exosomes by unique engineered approaches, the latest developed administration methods, and the therapeutic effects of exosomes used as the biocarriers of medications for cardiovascular disease treatment. Also, the possible therapeutic mechanisms and the potentials for transferring exosomes to the clinic for CVD treatment are discussed. The advances, in vivo and in vitro applications, modifications, mechanisms, and challenges summarized in this review will provide a general understanding of this promising strategy for CVD treatment.

Cardiac microRNAs: diagnostic and therapeutic potential

MicroRNAs are small non-coding post-translational biomolecules which, when expressed, modify their target genes. It is estimated that microRNAs regulate production of approximately 60% of all human proteins and enzymes that are responsible for major physiological processes. In cardiovascular disease pathophysiology, there are several cells that produce microRNAs, including endothelial cells, vascular smooth muscle cells, macrophages, platelets, and cardiomyocytes. There is a constant crosstalk between microRNAs derived from various cell sources. Atherosclerosis initiation and progression are driven by many pro-inflammatory and pro-thrombotic microRNAs. Atherosclerotic plaque rupture is the leading cause of cardiovascular death resulting from acute coronary syndrome (ACS) and leads to cardiac remodeling and fibrosis following ACS. MicroRNAs are powerful modulators of plaque progression and transformation into a vulnerable state, which can eventually lead to plaque rupture. There is a growing body of evidence which demonstrates that following ACS, microRNAs might inhibit fibroblast proliferation and scarring, as well as harmful apoptosis of cardiomyocytes, and stimulate fibroblast reprogramming into induced cardiac progenitor cells. In this review, we focus on the role of cardiomyocyte-derived and cardiac fibroblast-derived microRNAs that are involved in the regulation of genes associated with cardiomyocyte and fibroblast function and in atherosclerosis-related cardiac ischemia. Understanding their mechanisms may lead to the development of microRNA cocktails that can potentially be used in regenerative cardiology.

Evaluation of microRNA Expression Features in Patients with Various Types of Arterial Damage: Thoracic Aortic Aneurysm and Coronary Atherosclerosis

Circulating serum miRNA are increasingly used as biomarkers and potential treatment targets in several clinical scenarios, including cardiovascular diseases. However, the current data on circulating miRNA in thoracic aorta aneurism (TAA) patients are inconclusive. The aim of the present study is to compare the levels of several circulating miRNA in patients with degenerative TAA, coronary artery disease (CAD), and controls for special profile identification. We have identified several candidates for the role of new biomarkers: miR-143-3p, miR-181-5p, miR-126-3p, miR-126-5p, miR-145-5p, miR-150-5p, and miR-195-5p.

MATERIALS AND METHODS

Serum samples of 100 patients were analyzed, including 388 TAA patients scheduled for elective surgery, 67 patients with stable CAD and 17 controls, were used for miRNA isolation and identification.

RESULTS

More specific for TAA with very high predictive ability in ROC analysis was an increase in the levels of miR-21-5p, miR-29b-5p, miR-126-5p/-3p, miR-181b-5p, and miR-92a-3p, with the latter microRNA being investigated as a novel potential marker of TAA for the first time.

CONCLUSION

TAA and CAD patients demonstrated a significant increase in the levels of circulating miR-126-5p/-3p, miR-181b-5p, and miR-29b-3p. More specific for TAA with very high predictive ability in ROC analysis was an increase in the levels of miR-21-5p, -29b-5p, -126-5p/-3p, 181b-5p, and -92a-3p, with the latter microRNA being investigated as a potential marker of TAA for the first time.

MicroRNAs as a Potential Biomarker in the Diagnosis of Cardiovascular Diseases

Cardiovascular diseases (CVD) are the leading cause of death in most developed countries. MicroRNAs (miRNAs) are highly investigated molecules not only in CVD but also in other diseases. Several studies on miRNAs continue to reveal novel miRNAs that may play a role in CVD, in their pathogenesis in diagnosis or prognosis, but evidence for clinical implementation is still lacking. The aim of this study is to clarify the diagnostic potential of miRNAs in some CVDs.

High miR-126-3p levels associated with cardiovascular events in a general population

BACKGROUND

Endothelial dysfunction is a forerunner of atherosclerosis, leading to cardiovascular disease, and albuminuria is a marker of endothelial dysfunction. Circulating levels of microRNAs are emerging as potential biomarkers for cardiovascular disease. Here we estimate the predictive value of a plasma microRNAs signature associated with albuminuria in the incidence of cardiovascular events.

METHODS

Plasma microRNAs quantified in hypertensive patients by next generation sequencing were validated in a cohort of patients and controls by real-time quantitative PCR. The microRNAs found to be associated with albuminuria were analysed for their prognostic value in predicting cardiovascular events incidence on a retrospective, population-based study (Hortega Study), using Cox proportional hazard models.

RESULTS

A plasma microRNA profile was identified in the discovery cohort (n = 48) associated with albuminuria and three microRNAs (miR-126-3p, miR-1260b and miR-374a-5p) were confirmed in the validation cohort (n = 98). The microRNA signature discriminates urinary albumin excretion at baseline (n = 1025), and predicts the incidence of cardiovascular events and coronary heart disease and stroke in a general population retrospective study within a 14-year follow-up (n = 926). High miR-126-3p levels were associated with a shorter time free of both cardiovascular events (HR=1.48, (1.36-1.62), p < 0.0001), as well as coronary artery disease and stroke combined (HR=2.49, (2.19-2.83), p < 0.0001).

CONCLUSIONS

An increased plasma microRNAs profile was identified in hypertensive patients with albuminuria. Increased miR-126-3p suggest it may serve as a prognostic marker for cardiovascular events in a long-term general population. Further studies will assess the potential role of miR-126-3p as a guide for the status of endothelial dysfunction.

New Insights into Pathophysiology and New Risk Factors for ACS

Cardiovascular disease still represents the main cause of mortality worldwide. Despite huge improvements, atherosclerosis persists as the principal pathological condition, both in stable and acute presentation. Specifically, acute coronary syndromes have received substantial research and clinical attention in recent years, contributing to improve overall patients' outcome. The identification of different evolution patterns of the atherosclerotic plaque and coronary artery disease has suggested the potential need of different treatment approaches, according to the mechanisms and molecular elements involved. In addition to traditional risk factors, the finer portrayal of other metabolic and lipid-related mediators has led to higher and deep knowledge of atherosclerosis, providing potential new targets for clinical management of the patients. Finally, the impressive advances in genetics and non-coding RNAs have opened a wide field of research both on pathophysiology and the therapeutic side that are extensively under investigation.

Potential roles of microRNAs and long noncoding RNAs as diagnostic, prognostic and therapeutic biomarkers in coronary artery disease

Coronary artery disease (CAD), which is mainly caused by atherosclerotic processes in coronary arteries, became a significant health issue. MicroRNAs (miRNAs), and long noncoding RNAs (lncRNAs), have been shown to be stable in plasma and could thereby be adopted as biomarkers for CAD diagnosis and treatment. MiRNAs can regulate CAD development through different pathways and mechanisms, including modulation of vascular smooth muscle cell (VSMC) activity, inflammatory responses, myocardial injury, angiogenesis, and leukocyte adhesion. Similarly, previously studies have indicated that the causal effects of lncRNAs in CAD pathogenesis and their utility in CAD diagnosis and treatment, has been found to lead to cell cycle transition, proliferation dysregulation, and migration in favour of CAD development. Differential expression of miRNAs and lncRNAs in CAD patients has been identified and served as diagnostic, prognostic and therapeutic biomarkers for the assessment of CAD patients. Thus, in the current review, we summarize the functions of miRNAs and lncRNAs, which aimed to identify novel targets for the CAD diagnosis, prognosis, and treatment.

MicroRNA in the Diagnosis and Treatment of Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX), a broad-spectrum chemotherapy drug, is widely applied to the treatment of cancer; however, DOX-induced cardiotoxicity (DIC) limits its clinical therapeutic utility. However, it is difficult to monitor and detect DIC at an early stage using conventional detection methods. Thus, sensitive, accurate, and specific methods of diagnosis and treatment are important in clinical practice. MicroRNAs (miRNAs) belong to non-coding RNAs (ncRNAs) and are stable and easy to detect. Moreover, miRNAs are expected to become biomarkers and therapeutic targets for DIC; thus, there are currently many studies focusing on the role of miRNAs in DIC. In this review, we list the prominent studies on the diagnosis and treatment of miRNAs in DIC, explore the feasibility and difficulties of using miRNAs as diagnostic biomarkers and therapeutic targets, and provide recommendations for future research.

FRET cascade miRNA addition probe from non-crosstalk DNA photonic wire assisted with clustering algorithm for early diagnosis of acute myocardial infarction

Early and accurate diagnosis of acute myocardial infarction (AMI) can significantly reduce patient mortality. A variety of miRNAs are found to dysregulate in AMI patients, but the up- or down-regulation of a specific miRNA may not be evident in the early stage, making it difficult to achieve accurate diagnosis. Here, proposing the design that DNA photonic wire (PW) with no spectral crosstalk would make an excellent template for miRNA conjoint analysis, we report the construction of a miRNA addition probe for the additive analysis of two up-regulated miRNAs (miR-133a and miR-208a) for early diagnosis of AMI in clinical serum samples. A three-dye non-crosstalk DNA PW is built to form the two-step fluorescence resonance energy transfer (FRET) cascade system, in which three paths can blocking the FRET cascade for separate or additive analysis of the two miRNAs. K-Means clustering algorithm is further utilized to classify the output signals of the miRNA addition probe, achieving a 100% accurate diagnosis of early AMI in both the training (n = 40) and validation (n = 19) cohorts of clinical serum samples.

microRNAs as Biomarkers of Endothelial Dysfunction and Therapeutic Target in the Pathogenesis of Atrial Fibrillation

The pathophysiology of atrial fibrillation (AF) may involve atrial fibrosis/remodeling and dysfunctional endothelial activities. Despite the currently available treatment approaches, the progression of AF, its recurrence rate, and the high mortality risk of related complications underlay the need for more advanced prognostic and therapeutic strategies. There is increasing attention on the molecular mechanisms controlling AF onset and progression points to the complex cell to cell interplay that triggers fibroblasts, immune cells and myofibroblasts, enhancing atrial fibrosis. In this scenario, endothelial cell dysfunction (ED) might play an unexpected but significant role. microRNAs (miRNAs) regulate gene expression at the post-transcriptional level. In the cardiovascular compartment, both free circulating and exosomal miRNAs entail the control of plaque formation, lipid metabolism, inflammation and angiogenesis, cardiomyocyte growth and contractility, and even the maintenance of cardiac rhythm. Abnormal miRNAs levels may indicate the activation state of circulating cells, and thus represent a specific read-out of cardiac tissue changes. Although several unresolved questions still limit their clinical use, the ease of accessibility in biofluids and their prognostic and diagnostic properties make them novel and attractive biomarker candidates in AF. This article summarizes the most recent features of AF associated with miRNAs and relates them to potentially underlying mechanisms.

Suitable biomarkers for post-mortem differentiation of cardiac death causes: Quantitative analysis of miR-1, miR-133a and miR-26a in heart tissue and whole blood

Cardiovascular diseases are the most common causes of death worldwide. Cardiac death can occur as reaction to myocardial infarction (MI). A diagnostic challenge arises for sudden unexpected death (SUD) cases with structural abnormalities (SA) or without any structural abnormalities (without SA). Therefore, the identification of reliable biomarkers to differentiate cardiac cases from each other is necessary. In the current study, the potential of different microRNAs (miRNAs) as biomarkers in tissue and blood samples of cardiac death cases was analyzed. Blood and tissue samples of 24 MI, 21 SUD and 5 control (C) cases were collected during autopsy. Testing for significance and receiver operating characteristic analysis (ROC) were performed. The results show that miR-1, miR-133a and miR-26a possess a high diagnostic power to discriminate between different cardiac death causes in whole blood and in tissue.

The Involvement of Krüppel-like Factors in Cardiovascular Diseases

Krüppel-like factors (KLFs) are a set of DNA-binding proteins belonging to a family of zinc-finger transcription factors, which have been associated with many biological processes related to the activation or repression of genes, inducing cell growth, differentiation, and death, and the development and maintenance of tissues. In response to metabolic alterations caused by disease and stress, the heart will undergo cardiac remodeling, leading to cardiovascular diseases (CVDs). KLFs are among the transcriptional factors that take control of many physiological and, in this case, pathophysiological processes of CVD. KLFs seem to be associated with congenital heart disease-linked syndromes, malformations because of autosomal diseases, mutations that relate to protein instability, and/or loss of functions such as atheroprotective activities. Ischemic damage also relates to KLF dysregulation because of the differentiation of cardiac myofibroblasts or a modified fatty acid oxidation related to the formation of a dilated cardiomyopathy, myocardial infarctions, left ventricular hypertrophy, and diabetic cardiomyopathies. In this review, we describe the importance of KLFs in cardiovascular diseases such as atherosclerosis, myocardial infarction, left ventricle hypertrophy, stroke, diabetic cardiomyopathy, and congenital heart diseases. We further discuss microRNAs that have been involved in certain regulatory loops of KLFs as they may act as critical in CVDs.

Diagnostic and prognostic significance of miR-451a in patients with atherosclerosis

OBJECTIVES

Atherosclerosis (AS) is a chronic inflammatory vascular disease. This study aimed to detect the expression level of miR-451a and investigate the diagnostic and prognostic values of miR-451a for AS patients.

METHODS

The relative expression of miR-451a was assessed by qRT-PCR. Comparison of groups was analyzed with the t-test and chi-squared test. Pearson analysis was used to validate the correlation of miR-451 with CRP and CIMT. The receiver operating characteristic (ROC) curves, K-M analysis, and Cox regression analysis were conducted to explore the roles of miR-451a in diagnosing AS patients and predicting outcomes of AS patients.

RESULTS

The expression of miR-451a was significantly decreased in the serum of AS patients. The results of Pearson analysis showed the expression of miR-451a was negatively correlated with CRP and CIMT. The data of ROC proposed miR-451a could differentiate AS patients from healthy individuals with high sensitivity and specificity. K-M analysis and Cox regression showed miR-451a might be an independent biomarker of suffering cardiovascular endpoint diseases in AS patients. The expression of miR-451a was obviously inhibited in AS patients with cardiovascular endpoint events.

CONCLUSION

Deregulation of miR-451a might be associated with the development of AS. MiR-451a might be used as a promising diagnostic and prognostic biomarker for clinical treatment of AS patients.

MicroRNA-499-5p promotes vascular smooth muscle cell proliferation and migration via inhibiting SOX6

Atherosclerosis (AS) is the primary etiology of cardiovascular disease, which is considered the leading cause of death all over the world. MicroRNA miR-499-5p was involved in the functional regulation of myocardial and skeletal muscle, whereas its role in atherosclerosis, especially in vascular smooth muscle cells (VSMCs), remains unclear. Our study aims to investigate the effects of miR-499-5p in the proliferation and migration of VSMCs and potential mechanisms. We used mouse aortic vascular smooth muscle cells (MOVAS) and ApoE^-/- mice to establish the models of AS in vitro and in vivo, respectively. RT-PCR was performed to detect the expression level of miR-499-5p. Subsequently, Cell Counting Kit-8 (CCK-8) assays, Transwell assays, and wound-healing assays were used to evaluate cell proliferation and migration. Dual-luciferase reporter assay was performed to validate the interaction between miR-499-5p and SOX6. miR-499-5p significantly increased in aorta tissues of mice in AS tissues and vascular smooth muscle cells treated with ox-LDL. miR-499-5p overexpression could promote the proliferation and migration of MOVAS. Bioinformatics analysis predicted and further experiments verified that miR-499-5p could directly bind to the 3'-untranslated region (UTR) region of SOX6. Further, miR-499-5p induced an increased expression of smooth muscle proliferation and migration-related genes, PCNA, cyclin D1, and matrix metalloproteinase (MMP2), as well as the decreased expression of proliferation inhibiting factor p21, which was significantly reversed by SOX6 overexpression. miR-499-5p boosts the proliferation and migration of smooth muscle cells by binding and inhibiting SOX6 expression. The miR-499-5p/SOX6 axis may present a promising therapeutic implication for the prevention and treatment of cardiovascular diseases.

Silencing hsa_circ_0049271 attenuates hypoxia-reoxygenation (H/R)-induced myocardial cell injury via the miR-17-3p/FZD4 signaling axis

Background

This study sought to explore the role and molecular mechanism of circ_0049271 in hypoxia-reoxygenation (H/R)-induced cardiomyocyte injury.

Methods

Significantly upregulated circular ribonucleic acids (circRNAs) in Gene Expression Omnibus (GEO) data sets were identified using a Venn diagram. A H9c2 (rat cardiomyocytes) cell model of acute myocardial infarction (AMI) was induced by 1% H/R. Quantitative reverse transcription-polymerase chain reaction was used to detect the expression levels of circ_0049271, miR-17-3p, and FZD4 in clinical blood samples and cells, and Cell Counting Kit-8 (CCK-8) was used to determine the proliferation rate of the cells in each group. Next, flow cytometry and Western blot were used to evaluate cell apoptosis. Biochemical tests and enzyme-linked immunosorbent assays (ELISAs) were then used to determine the activities/levels of the cell damage markers [i.e., creatine kinase (CK) and lactate dehydrogenase (LDH)], oxidative stress substances [i.e., malondialdehyde (MDA), reactive oxygen species (ROS), and superoxide dismutase (SOD)], and inflammatory factors [i.e., interleukin (IL)-1β, IL-6, and IL-8]. In addition, intermolecular interactions were verified using dual-luciferase reporter and RNA pull-down experiments.

Results

Circ_0049271 was significantly upregulated in both the blood of the AMI patients and the H/R-induced H9c2 cells. The knockdown of circ_0049271 increased the cell proliferation rate, decreased the apoptosis rate, inhibited oxidative stress (ROS and MDA were upregulated, and SOD was downregulated) and inflammatory responses (IL-1, IL-6, and IL-8 were downregulated), and relieved cell damage. However, the overexpression of circ_0049271 promoted H/R-induced H9c2 cell damage. Further experiments showed that miR-17-3p was a target of circ_0049271, and miR-17-3p was negatively correlated with circ_0049271 in the AMI blood samples. Additionally, miR-17-3p was found to target FZD4. A further exploration also revealed that miR-17-3p knockdown or FZD4 overexpression reversed the effects of si-circ_0049271 on the H/R-induced H9c2 cells; that is, miR-17-3p knockdown or FZD4 overexpression promoted H/R-induced injury in the H9c2 cells.

Conclusions

Circ_0049271 promoted cellular function damage (e.g., proliferation inhibition, apoptosis, oxidative stress, and inflammation) in H/R-induced H9c2 cardiomyocytes via the miR-17-3p/FZD4 signaling axis.

Association of Genetic Polymorphisms and Serum Levels of miR-1-3p with Postoperative Mortality following Abdominal Aortic Aneurysm Repair

BACKGROUND

Several miRNAs have been implicated in the clinical outcomes of cardiovascular disorders, but the role of miR-1-3p in abdominal aortic aneurysm (AAA) prognosis remains unclear. This study aimed to investigate the correlation of single nucleotide polymorphisms (SNPs) in pri-miR-1-3p and mature miR-1-3p expression with postoperative mortality of AAA patients.

METHODS

A total of 230 AAA patients who received AAA repair were recruited and followed up for 5 years. SNP genotyping was carried out using KASP method and relative expression of serum miR-1-3p was measured with qRT-PCR.

RESULTS

Multivariate Cox regression analyses showed that both rs2155975 and rs4591246 variant genotypes were associated with increased all-cause mortality of postoperative AAA patients after adjusting possible confounders. Patients who died tended to have lower baseline miR-1-3p expression (overall and for age < 65 years, aneurysm-related death or cardiac death subgroup) when compared to alive patients; further Cox regression yielded an independent relationship of preoperative low serum miR-1-3p levels with incidents of all-cause death. Patients carrying rs2155975 AG + GG or rs4591246 AG + AA genotype had a higher ratio of low miR-1-3p levels in contrast to those with AA or GG genotype, respectively. The Kaplan-Meier survival curves suggested that the combined genotype in rs2155975 or rs4591246 and low miR-1-3p levels could decrease the overall survival of AAA patients during 5-year follow-up.

CONCLUSIONS

This pilot study demonstrated the importance of rs2155975 and rs4591246 polymorphisms and baseline serum miR-1-3p levels as promising markers to predict mortality among patients following AAA repair.

MicroRNAs as prognostic biomarkers for (cancer-associated) venous thromboembolism

MicroRNAs (miRNAs) are small noncoding RNAs with gene regulatory functions and are commonly dysregulated in disease states. As miRNAs are relatively stable, easily measured, and accessible from plasma or other body fluids, they are promising biomarkers for the diagnosis and prediction of cancer and cardiovascular diseases. Venous thromboembolism (VTE) is the third most common cardiovascular disease worldwide with high morbidity and mortality. The suggested roles of miRNAs in regulating the pathophysiology of VTE and as VTE biomarkers are nowadays more evidenced. Patients with cancer are at increased risk of developing VTE compared to the general population. However, current risk prediction models for cancer-associated thrombosis (CAT) perform suboptimally, and novel biomarkers are therefore urgently needed to identify which patients may benefit the most from thromboprophylaxis. This review will first discuss how miRNAs mechanistically contribute to the pathophysiology of VTE. Next, the potential use of miRNAs as predictive biomarkers for VTE in subjects without cancer is reviewed, followed by an in-depth focus on CAT. Several of the identified miRNAs in CAT were found to be differentially regulated in VTE as well, giving clues on the pathophysiology of CAT. We propose that subsequent studies should be adequately sized to determine which panel of miRNAs best predicts VTE and CAT. Thereafter, validation studies using comparable patient populations are required to ultimately unveil whether miRNAs-as standalone or incorporated into existing risk models-are promising valuable VTE and CAT biomarkers.

microRNAs as biomarkers of risk of major adverse cardiovascular events in atrial fibrillation

Atrial fibrillation is a complex and multifactorial disease. Although prophylactic anticoagulation has great benefits in avoiding comorbidities, adverse cardiovascular events still occur and thus in recent decades, many resources have been invested in the identification of useful markers in the prevention of the risk of MACE in these patients. As such, microRNAs, that are small non-coding RNAs whose function is to regulate gene expression post-transcriptionally, have a relevant role in the development of MACE. miRNAs, have been investigated for many years as potential non-invasive biomarkers of several diseases. Different studies have shown their utility in the diagnosis and prognosis of cardiovascular diseases. In particular, some studies have associated the presence of certain miRNAs in plasma with the development of MACE in AF. Despite these results, there are still many efforts to be done to allow the clinical use of miRNAs. The lack of standardization concerning the methodology in purifying and detecting miRNAs, still provides contradictory results. miRNAs also have a functional impact in MACE in AF through the dysregulation of immunothrombosis. Indeed, miRNAs may be a link between MACE and inflammation, through the regulation of neutrophil extracellular traps that are a key element in the establishment and evolution of thrombotic events. The use of miRNAs as therapy against thromboinflammatory processes should also be a future approach to avoid the occurrence of MACE in atrial fibrillation.

Role of noncoding RNAs in cardiac ageing

The global population is estimated to reach 9.8 billion by 2050, of which 2.1 billion will comprise individuals above 60 years of age. As the number of elderly is estimated to double from 2017, it is a victory of the modern healthcare system but also worrisome as ageing, and the onset of chronic disease are correlated. Among other chronic conditions, cardiovascular diseases (CVDs) are the leading cause of death in the aged population. While the underlying cause of the age-associated development of CVDs is not fully understood, studies indicate the role of non-coding RNAs such as microRNAs (miRNAs) and long noncoding RNAs (lnc-RNAs) in the development of age-associated CVDs. miRNAs and lnc-RNAs are non-coding RNAs which control gene expression at the post-transcriptional level. The expression of specific miRNAs and lnc-RNAs are reportedly dysregulated with age, leading to cardiovascular system changes and ultimately causing CVDs. Since miRNAs and lnc-RNAs play several vital roles in maintaining the normal functioning of the cardiovascular system, they are also being explored for their therapeutic potential as a treatment for CVDs. This review will first explore the pathophysiological changes associated with ageing. Next, we will review the known mechanisms underlying the development of CVD in ageing with a specific focus on miRNA and lnc-RNAs. Finally, we will discuss the therapeutic options and future challenges towards healthy cardiac ageing. With the global ageing population on the rise, this review will provide a fundamental understanding of some of the underlying molecular mechanisms of cardiac ageing.

Peripheral blood RNA biomarkers for cardiovascular disease from bench to bedside: a position paper from the EU-CardioRNA COST action CA17129

Despite significant advances in the diagnosis and treatment of cardiovascular diseases, recent calls have emphasized the unmet need to improve precision-based approaches in cardiovascular disease. Although some studies provide preliminary evidence of the diagnostic and prognostic potential of circulating coding and non-coding RNAs, the complex RNA biology and lack of standardization have hampered the translation of these markers into clinical practice. In this position paper of the CardioRNA COST action CA17129, we provide recommendations to standardize the RNA development process in order to catalyse efforts to investigate novel RNAs for clinical use. We list the unmet clinical needs in cardiovascular disease, such as the identification of high-risk patients with ischaemic heart disease or heart failure who require more intensive therapies. The advantages and pitfalls of the different sample types, including RNAs from plasma, extracellular vesicles, and whole blood, are discussed in the sample matrix, together with their respective analytical methods. The effect of patient demographics and highly prevalent comorbidities, such as metabolic disorders, on the expression of the candidate RNA is presented and should be reported in biomarker studies. We discuss the statistical and regulatory aspects to translate a candidate RNA from a research use only assay to an in-vitro diagnostic test for clinical use. Optimal planning of this development track is required, with input from the researcher, statistician, industry, and regulatory partners.

Fluoropyrimidine‑induced cardiotoxicity in colorectal cancer patients: a prospective observational trial (CHECKPOINT)

Fluoropyrimidines (FP) are the backbone chemotherapy in colorectal cancer (CRC) treatment; however, their use is associated with cardiotoxicity, which is underreported. In the present study, it was aimed to prospectively determine the incidence rates and related risk factors of FP‑induced cardiotoxicity (FIC) in CRC patients and at identifying predictive biomarkers. A total of 129 consecutive previously untreated CRC patients underwent active cardiological monitoring, including 5‑items simplified questionnaire on symptoms, electrocardiogram (ECG) and plasma sample collection during FP chemotherapy. FIC was defined as the presence of ECG alterations and/or the arising of at least one symptom of chest pain, dyspnoea, palpitations or syncope. The primary objective was the evaluation of FIC incidence. Secondary objectives were the correlation of FIC with well‑known cardiological risk factors and the identification of circulating biomarkers (serum levels of troponin I, pro hormone BNP; miRNA analysis) as predictors of FIC. A total of 20 out of 129 (15.5%) patients experienced FIC. The most common symptoms were dyspnoea (60%) and chest pain (40%), while only 15% of patients presented ECG alterations, including one acute myocardial infarction. Retreatment with FP was attempted in 90% of patients with a favourable outcome. Despite 48% of patients having cardiological comorbidities, an increased FIC was not observed in this subgroup. Only the subgroup of females with the habit of alcohol consumption showed an increased risk of FIC. None of the circulating biomarkers evaluated demonstrated a clinical utility as FIC predictors. FIC can be an unexpected, life‑threatening adverse event that can limit the subsequent treatment choices in patients with CRC. In this prospective study, well‑known cardiological comorbidities were not related to higher FIC risk and circulating biomarkers predictive of toxicity could not be found. With careful monitoring, mainly based on symptoms, almost all patients completed the FP treatment.

High-glucose induced toxicity in HK-2 cells can be alleviated by inhibition of miRNA-320c

Diabetic nephropathy (DN) is a major healthcare challenge worldwide. MiRNAs exert a regulatory effect on the progress of DN. Our study proposed to investigate the miR-320c expression and its function on the pathogenesis of DN in vitro. The level of miR-320c in HK-2 cells was quantified by RT-qPCR. Cell morphology, invasion, and migration were observed by optical microscope, Transwell invasion assay, and scratch wound assay. Then, the levels of PTEN, α-SMA, vimentin, E-cadherin, p-PI3K, PI3K, AKT, and p-AKT were analyzed through western blotting. A Dual-luciferase reporter assay was conducted to explore the target relationship between miR-320c and PTEN. It was discovered that miR-320c was over-expressed in high glucose (HG)-treated HK-2 cells. Furthermore, inhibition of miR-320c could alleviate the epithelial-mesenchymal transition (EMT) of HG-induced HK-2 cells and retain the normal morphology of HK-2 cells. Additionally, the miR-320c inhibitor decreased the invasiveness and migration of HG-treated HK-2 cells. Next, the target gene of miR-320c, PTEN, was identified, and the function of miR-320c was reversed by down-regulation of PTEN. Finally, we found inhibition of miR-320c restrained the PI3K/AKT pathway. Therefore, inhibition of miR-320c could alleviate toxicity of HK-2 cells induced by HG via targeting PTEN and restraining the PI3K/AKT pathway, illustrating that miR-320c may act as a new biomarker in the diagnosis of DN.

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.

Reductions in extracellular vesicle-associated microRNA-126 levels in coronary blood after acute myocardial infarction: A retrospective study

Background

Acute Myocardial Infarction (AMI) is a kind of cardiovascular disease with high mortality and incidence. Extracellular vesicles (EVs) and microRNA-126 (miR-126) are known to play important role in the development and prognosis of several cardiovascular diseases. Therefore, this study aimed to investigate the changes in Extracellular vesicle (EV)-associated miR-126 levels in the coronary blood of patients with AMI to explore the relationship between miR-126 levels and AMI.

Materials and methods

We analyzed EV-associated miR-126 in the coronary blood of patients with AMI and stable coronary artery disease (SCAD) using quantitative reverse transcription polymerase chain reaction (qRT-PCR).

Results

We tested the coronary blood of 20 patients with AMI and 20 with SCAD. The mean age of the patients was 58.8 ± 10.3 years and 32 (80%) were men. We observed that the EV-associated miR-126 levels were lower in patients with AMI [median = 0.13; interquartile range (IQR): 0.08–0.22] than in patients with SCAD (median = 0.37; IQR: 0.26–0.48) (P &lt; 0.001). In addition, the levels of miR-126 were negatively associated with the Thrombolysis in Myocardial Infarction (TIMI) score (r = −0.66, P = 0.001).

Conclusion

Reduction of EV-associated miR-126 levels in the coronary blood of patients with AMI may be involved in acute coronary thrombosis events.

The role of miRNAs in the diagnosis of stable atherosclerosis of different arterial territories: A critical review

Atherosclerotic disease is a major cause of morbidity and mortality worldwide. Atherosclerosis may be present in different arterial territories and as a single- or multi-territorial disease. The different phenotypes of atherosclerosis are attributable only in part to acquired cardiovascular risk factors and genetic Mendelian inheritance. miRNAs, which regulate the gene expression at the post-transcriptional level, may also contribute to such heterogeneity. Numerous miRNAs participate in the pathophysiology of atherosclerosis by modulating endothelial function, smooth vascular cell function, vascular inflammation, and cholesterol homeostasis in the vessel, among other biological processes. Moreover, miRNAs are present in peripheral blood with high stability and have the potential to be used as non-invasive biomarkers for the diagnosis of atherosclerosis. However, the circulating miRNA profile may vary according to the involved arterial territory, considering that atherosclerosis expression, including the associated molecular phenotype, varies according to the affected arterial territory. In this review, we discuss the specific circulating miRNA profiles associated with atherosclerosis of different arterial territories, the common circulating miRNA profile of stable atherosclerosis irrespective of the involved arterial territory, and the circulating miRNA signature of multi-territorial atherosclerosis. miRNAs may consist of a simple non-invasive method for discriminating atherosclerosis of different arterial sites. The limitations of miRNA profiling for such clinical application are also discussed.

Clinical Application of Serum microRNAs in Atherosclerotic Coronary Artery Disease

MicroRNAs (miRs) are promising diagnostic, prognostic and therapeutic biomolecules for atherosclerotic cardiovascular disease. Atherosclerotic occlusive disease concerns a large population of patients, carrying the highest incidence of fatal and non-fatal adverse events, such as myocardial infarction, ischemic stroke, and limb ischemia, worldwide. Consistently, miRs are involved in regulation and pathogenesis of atherosclerotic coronary artery disease (CAD), acute coronary syndromes (ACS), both with ST-segment (STEMI) and non-ST segment elevation myocardial infarctions (NSTEMI), as well as cardiac remodeling and fibrosis following ACS. However, the genetic and molecular mechanisms underlying adverse outcomes in CAD are multifactorial, and sometimes difficult to interpret for clinicians. Therefore, in the present review paper we have focused on the clinical meaning and the interpretation of various miRs findings, and their potential application in routine clinical practice.

miRNA-Mediated Epigenetic Regulation of Treatment Response in RA Patients—A Systematic Review

This study aimed to evaluate the role of microRNAs (miRNA) as biomarkers of treatment response in rheumatoid arthritis (RA) patients through a systematic review of the literature. The MEDLINE and Embase databases were searched for studies including RA-diagnosed patients treated with disease-modifying antirheumatic drugs (DMARDs) that identify miRNAs as response predictors. Review inclusion criteria were met by 10 studies. The main outcome of the study was the response to treatment, defined according to EULAR criteria. A total of 839 RA patients and 67 healthy donors were included in the selected studies. RA patients presented seropositivity for the rheumatoid factor of 74.7% and anti-citrullinated C-peptide antibodies of 63.6%. After revision, 15 miRNAs were described as treatment response biomarkers for methotrexate, anti-tumour necrosis factor (TNF), and rituximab. Among treatments, methotrexate presented the highest number of predictor miRNAs: miR-16, miR-22, miR-132, miR-146a and miR-155. The most polyvalent miRNAs were miR-146a, predicting response to methotrexate and anti-TNF, and miR-125b, which predicts response to infliximab and rituximab. Our data support the role of miRNAs as biomarkers of treatment response in RA and point to DMARDs modifying the miRNAs expression. Nevertheless, further studies are needed since a meta-analysis that allows definitive conclusions is not possible due to the lack of studies in this field.

Differential expression of aqueous humor microRNAs in central retinal vein occlusion and its association with matrix metalloproteinases: a pilot study

The aim of this study is to investigate the differential expression of microRNAs (miRNAs) in the aqueous humor (AH) of patients with central retinal vein occlusion (CRVO), and their association with AH matrix metalloproteinase (MMP) activity. Eighteen subjects, including 10 treatment naïve patients with CRVO and 8 control subjects, scheduled for intravitreal injection and cataract surgery, respectively, were included. AH samples were collected at the beginning of the procedure. A microarray composed of 84 miRNAs was performed to identify differentially expressed miRNAs in CRVO AH, which were further analyzed using bioinformatic tools to identify directly related cytokines/proteins. Eight miRNAs (hsa-mir-16-5p, hsa-mir-142-3p, hsa-mir-19a-3p, hsa-mir-144-3p, hsa-mir-195-5p, hsa-mir-17-5p, hsa-mir-93-5p, and hsa-mir-20a-5p) were significantly downregulated in the CRVO group. Bioinformatic analysis revealed a direct relationship among downregulated miRNAs, CRVO, and the following proteins: MMP-2, MMP-9, tumor necrosis factor, transforming growth factor beta-1, caspase-3, interleukin-6, interferon gamma, and interleukin-1-beta. Activities of MMP-2 and -9 in AH were detected using gelatin zymography, showing significant increase in the CRVO group compared to the control group (p < 0.01). This pilot study first revealed that MMP-2 and -9 were directly related to downregulated miRNAs and showed significant increase in activity in AH of patients with CRVO. Therefore, the relevant miRNAs and MMPs in AH could serve as potential biomarkers or therapeutic targets for CRVO.

Evaluation of Circulating MicroRNAs and Adipokines in Breast Cancer Survivors with Arm Lymphedema

Breast cancer-related lymphedema (BCRL) is a form of secondary lymphedema that is characterized by abnormal swelling of one or both arms due to the accumulation of lymph fluid in the interstitial tissue spaces, resulting from obstruction of the lymphatic vessels due to surgery insults, radiotherapy, or chemotherapy. Due to the multifactorial nature of this condition, the pathogenesis of secondary lymphedema remains unclear and the search for molecular factors associated with the condition is ongoing. This study aimed to identify serum microRNAs and adipokines associated with BCRL. Blood was collected from 113 breast cancer survivors and processed to obtain serum for small RNA-sequencing (BCRL vs. non-BCRL, n = 7 per group). MicroRNAs that were differentially expressed (fold change >1.5, p < 0.05) between lymphedema cases and those without lymphedema were further quantified in a validation cohort through quantitative reverse transcription PCR (BCRL n = 16, non-BCRL, n = 83). Leptin and adiponectin levels were measured in a combined cohort (BCRL n = 23, non-BCRL n = 90) using enzyme-linked immunosorbent assays. Two of the most significantly upregulated microRNAs, miR-199a-3p and miR-151a-3p, were strongly correlated with the onset of lymphedema and diabetes mellitus in the BCRL group. Leptin levels were higher in the BCRL cohort compared to the non-BCRL cohort (p < 0.05). A metabolic syndrome biomarker, the adiponectin/leptin ratio, was found to be lower in the BCRL group than in the non-BCRL group (median: 0.28 vs. 0.41, p < 0.05). Extensive studies on the mechanisms of the identified microRNAs and association of leptin with arm lymphedema may provide new insights on the potential biomarkers for lymphedema that should be followed up in a prospective cohort study.

Extracellular vesicles in vascular remodeling

Vascular remodeling contributes to the development of a variety of vascular diseases including hypertension and atherosclerosis. Phenotypic transformation of vascular cells, oxidative stress, inflammation and vascular calcification are closely associated with vascular remodeling. Extracellular vesicles (EVs) are naturally released from almost all types of cells and can be detected in nearly all body fluids including blood and urine. EVs affect vascular oxidative stress, inflammation, calcification, and lipid plaque formation; and thereby impact vascular remodeling in a variety of cardiovascular diseases. EVs may be used as biomarkers for diagnosis and prognosis, and therapeutic strategies for vascular remodeling and cardiovascular diseases. This review includes a comprehensive analysis of the roles of EVs in the vascular remodeling in vascular diseases, and the prospects of EVs in the diagnosis and treatment of vascular diseases.

Circulating miR-130a-3p is elevated in patients with cerebral atherosclerosis and predicts 2-year risk of cerebrovascular events

Background

Cerebral atherosclerosis (AS) leads to high risk of cerebrovascular events. This study aims to evaluate the diagnostic performance of serum microRNA-130a-3p (miR-130a-3p) in cerebral AS patients, and construct a logistic risk model for 2-year cerebrovascular events on the basis of the prognostic potential of miR-130a-3p.

Methods

Serum samples were collected from 74 cerebral AS patients and 62 control individuals, and miR-130a-3p expression was investigated using reverse transcription quantitative PCR. Risk factors related with cerebral AS were assessed using a logistic regression analysis, and the receiver operating characteristic analysis was performed to evaluate the diagnostic value of miR-130a-3p. The relationship between miR-130a-3p and cerebrovascular events was analyzed using a Kaplan–Meier method, and a logistic risk model was constructed for 2-year cerebrovascular events.

Results

Cerebral AS patients had elevated serum miR-130a-3p compared with controls (P < 0.001). Serum miR-130a-3p had diagnostic value (AUC = 0.899), and could significantly improve the diagnostic accuracy of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in cerebral AS patients (AUC = 0.992). High serum miR-130a-3p was independently related with high probability of cerebrovascular events (HR = 1.993, 95% CI = 1.205–2.897, P = 0.006), and a logistic risk model was constructed based on serum miR-130a-3p, hs-CRP, TC and LDL-C.

Conclusion

All the findings indicated that high serum miR-130a-3p had diagnostic potential to screen cerebral AS, and predicted the probability of cerebrovascular events after AS. The logistic risk model based on miR-130a-3p may provide an efficient method to predict 2-year cerebrovascular events in AS patients.