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

An exploration into the diagnostic capabilities of microRNAs for myocardial infarction using machine learning

BACKGROUND

MicroRNAs (miRNAs) have shown potential as diagnostic biomarkers for myocardial infarction (MI) due to their early dysregulation and stability in circulation after MI. Moreover, they play a crucial role in regulating adaptive and maladaptive responses in cardiovascular diseases, making them attractive targets for potential biomarkers. However, their potential as novel biomarkers for diagnosing cardiovascular diseases requires systematic evaluation.

METHODS

This study aimed to identify a miRNA biomarker panel for early-stage MI detection using bioinformatics and machine learning (ML) methods. miRNA expression data were obtained for early-stage MI patients and healthy controls from the Gene Expression Omnibus. Separate datasets were allocated for training and independent testing. Differential expression analysis was performed to identify dysregulated miRNAs in the training set. The least absolute shrinkage and selection operator (LASSO) was applied for feature selection to prioritize relevant miRNAs associated with MI. The selected miRNAs were used to develop ML models including support vector machine, Gradient Boosted, XGBoost, and a hard voting ensemble (HVE).

RESULTS

Differential expression analysis discovered 99 dysregulated miRNAs in the training set. LASSO feature selection prioritized 21 miRNAs. Ten miRNAs were identified in both the LASSO subset and independent test set. The HVE model trained with the selected miRNAs achieved an accuracy of 0.86 and AUC of 0.83 on the independent test set.

CONCLUSIONS

An integrated framework for robust miRNA selection from omics data shows promise for developing accurate diagnostic models for early-stage MI detection. The HVE model demonstrated good performance despite differences between training and test datasets.

Systematic review of microRNAs in human acute kidney injury

INTRODUCTION

Early diagnosis of acute kidney injury (AKI) is limited with current tools. MicroRNAs (miRNAs) are implicated in AKI pathogenesis in preclinical models, but less is known about their role in humans. We conducted a systematic review to identify dysregulated miRNAs in humans with AKI.

METHODS

We searched Ovid MEDLINE, Embase, Web of Science, and CENTRAL (August 21, 2023) for studies of human subjects with AKI. We excluded reviews and pre-clinical studies without human data. The primary outcome was dysregulated miRNAs in AKI. Two reviewers screened abstracts, reviewed full texts, performed data extraction and quality assessment (Newcastle Ottawa Scale).

RESULTS

We screened 2,456 reports and included 92 for synthesis without meta-analysis. All studies except one were observational. Studies were grouped by etiology of AKI: cardiac surgery-associated (CS-AKI, n = 13 studies), sepsis (n = 25), nephrotoxic (n = 9), kidney transplant (n = 26), and other causes (n = 19). In total, 128 miRNAs were identified to be dysregulated across AKI studies (45 miRNAs upregulated, 55 downregulated, 28 both). miR-21 was the most frequently reported (n = 17 studies) and it was increased in all etiologies except CS-AKI where it was decreased (n = 3 studies). Study limitations included bias due to targeted approaches, absence of clinical data/controls, and miRNA normalization methods. Overall study quality was fair (median 5/9, range 2-8 points).

CONCLUSION

Dysregulated miRNAs, particularly miR-21, have potential as AKI biomarkers. These results should be interpreted cautiously due to methodological limitations. Standardized methods and unbiased approaches are needed to validate candidate miRNA biomarkers.Registration: International Prospective Register of Systematic Reviews (PROSPERO CRD42020201253).

Genetic Polymorphism in miRNA Genes and Their Association with susceptibility of Coronary Heart Disease: An Updated Review

Coronary heart disease (CHD) remains a major public health concern worldwide, with a complex interplay of genetic, environmental and lifestyle factors contributing to its pathogenesis. The potential significance of microRNAs (miRNAs) in the onset and progression of CHD has attracted increasing attention in recent years. Small non-coding RNA molecules called miRNAs control gene expression at the post-transcriptional level. Dysregulation of miRNAs has been linked to a variety of biological processes, including cell division, proliferation, apoptosis, and inflammation. Numerous research studies have looked into the relationship between genetic variants in miRNA genes and CHD susceptibility. This review highlights the recent research work carried out to identify the relationship of miRNA genes polymorphism with the progression and susceptibility of CHD. Such studies could pave the way for the development of personalized strategies for CHD prevention and treatment based on an individual's genetic profile.

New insights into the cardio-renal benefits of SGLT2 inhibitors and the coordinated role of miR-30 family

Sodium-glucose co-transporter inhibitors (SGLTis) are the latest class of anti-hyperglycemic agents. In addition to inhibiting the absorption of glucose by the kidney causing glycosuria, these drugs also demonstrate cardio-renal benefits in diabetic subjects. miR-30 family, one of the most abundant microRNAs in the heart, has recently been linked to a setting of cardiovascular diseases and has been proposed as novel biomarkers in kidney dysfunctions as well; their expression is consistently dysregulated in a variety of cardio-renal dysfunctions. The mechanistic involvement and the potential interplay between miR-30 and SGLT2i effects have yet to be thoroughly elucidated. Recent research has stressed the relevance of this cluster of microRNAs as modulators of several pathological processes in the heart and kidneys, raising the possibility of these small ncRNAs playing a central role in various cardiovascular complications, notably, endothelial dysfunction and pathological remodeling. Here, we review current evidence supporting the pleiotropic effects of SGLT2is in cardiovascular and renal outcomes and investigate the link and the coordinated implication of the miR-30 family in endothelial dysfunction and cardiac remodeling. We also discuss the emerging role of circulating miR-30 as non-invasive biomarkers and attractive therapeutic targets for cardiovascular diseases and kidney diseases. Clinical evidence, as well as metabolic, cellular, and molecular aspects, are comprehensively covered.

The role of miR-134-5p in 7-ketocholesterol-induced human aortic endothelial dysfunction

Atherosclerotic cardiovascular diseases are the leading causes of morbidity and mortality worldwide. In our previous study, a panel of miRNA including miR-134-5p was deregulated in young acute coronary syndrome (ACS) patients. However, the roles of these ACS-associated miRNAs in endothelial dysfunction, an early event preceding atherosclerosis, remain to be investigated. In the present study, human aortic endothelial cells (HAECs) were treated with 7-ketocholesterol (7-KC) to induce endothelial dysfunction. Following treatment with 20 μg/ml 7-KC, miR-134-5p was significantly up-regulated and endothelial nitric oxide synthase (eNOS) expression was suppressed. Endothelial barrier disruption was evidenced by the deregulation of adhesion molecules including the activation of focal adhesion kinase (FAK), down-regulation of VE-cadherin, up-regulation of adhesion molecules (E-selectin and ICAM-1), increased expression of inflammatory genes (IL1B, IL6 and COX2) and AKT activation. Knockdown of miR-134-5p in 7-KC-treated HAECs attenuated the suppression of eNOS, the activation of AKT, the down-regulation of VE-cadherin and the up-regulation of E-selectin. In addition, the interaction between miR-134-5p and FOXM1 mRNA was confirmed by the enrichment of FOXM1 transcripts in the pull-down miRNA-mRNA complex. Knockdown of miR-134-5p increased FOXM1 expression whereas transfection with mimic miR-134-5p decreased FOXM1 protein expression. In summary, the involvement of an ACS-associated miRNA, miR-134-5p in endothelial dysfunction was demonstrated. Findings from this study could pave future investigations into utilizing miRNAs as a supplementary tool in ACS diagnosis or as targets for the development of therapeutics.

Sensitive Multiplexed MicroRNA Spatial Profiling and Data Classification Framework Applied to Murine Breast Tumors

MicroRNAs (miRNAs) are small RNAs that are often dysregulated in many diseases, including cancers. They are highly tissue-specific and stable, thus, making them particularly useful as biomarkers. As the spatial transcriptomics field advances, protocols that enable highly sensitive and spatially resolved detection become necessary to maximize the information gained from samples. This is especially true of miRNAs where the location their expression within tissue can provide prognostic value with regard to patient outcome. Equally as important as detection are ways to assess and visualize the miRNA's spatial information in order to leverage the power of spatial transcriptomics over that of traditional nonspatial bulk assays. We present a highly sensitive methodology that simultaneously quantitates and spatially detects seven miRNAs in situ on formalin-fixed paraffin-embedded tissue sections. This method utilizes rolling circle amplification (RCA) in conjunction with a dual scanning approach in nanoliter well arrays with embedded hydrogel posts. The hydrogel posts are functionalized with DNA probes that enable the detection of miRNAs across a large dynamic range (4 orders of magnitude) and a limit of detection of 0.17 zeptomoles (1.7 × 10-4 attomoles). We applied our methodology coupled with a data analysis pipeline to K14-Cre Brca1f/fTp53f/f murine breast tumors to showcase the information gained from this approach.

Exosomal miRNA-21-5p and miRNA-21-3p as key biomarkers of myocardial infarction

Objective

Coronary artery disease (CAD) is a debilitating condition that can lead to myocardial infarction (MI). Exosomal miRNAs (exo-miRNA) can be diagnostic biomarkers for detecting MI. Here, we conduct a study to evaluate the efficacy of exo-miRNA-21-5p/3p for early detection of MI.

Methods

A total of 135 CAD patients and 150 healthy subjects participated in this study. Additionally, we randomly divided 26 male Wistar rats (12 weeks old) into two groups: control and induced MI. Angiographic images were used to identify patients and healthy individuals of all genders. In the following, serum exosomes were obtained, and exo-miRNA-21-5p/3p was measured by reverse-transcriptase polymerase chain reaction.

Results

We observed an upregulation of exo-miRNA-21-5p/3p in CAD patient and MI-induced animal groups compared to controls. Analysis of the ROC curves defined 82% and 88% of the participants' exo-miRNA-21-5p and exo-miRNA-21-3p diagnostic power, respectively, which in the animal model was 92 and 82.

Conclusion

This study revealed that the mean expression levels of exo-miRNA-21-5p/3p were significantly increased in CAD patients and animal models of induced MI. Also, these results are associated with the atherogenic lipid profile of CAD patients, which may play an important role in the progression of the disease. Therefore, they can be considered as novel biomarkers.

Phthalate Exposure and Coronary Heart Disease: Possible Implications of Oxidative Stress and Altered miRNA Expression

The relationship between phthalate exposure and coronary heart disease (CHD) is still unclear. This study aimed to investigate the association between phthalate exposure and CHD and determine the possible atherogenic mechanisms of phthalates by assessing oxidative stress and altering miRNA expression. This case-control study included 110 participants (55 CHD patients and 55 healthy controls). The levels of oxidative stress markers, malondialdehyde (MDA), and superoxide dismutase (SOD), and the expression of miRNA-155 (miR-155) and miRNA-208a (miR-208a), were measured and correlated with the urinary mono-2-ethylhexyl phthalate (MEHP). Highly significant differences were detected between the CHD cases and the control group regarding MEHP, MDA, SOD, miR-155, and miR-208a (p-value < 0.001). Spearman correlations revealed a significant positive correlation between MDA and MEHP in urine (P = 0.001 and rs = 0.316) and a significant negative correlation between SOD and MEHP in urine (P < 0.001 and rs = -0.345). Furthermore, significant positive correlations were observed between miR-155 and urinary MEHP (P = 0.001 and rs = 0.318) and miR-208a and urinary MEHP (P < 0.001 and rs = -0.352). This study revealed an association between phthalate exposure, as indicated by urinary MEHP and CHD; altered expression of miR-155 and miR-208a and oxidative stress could be the fundamental mechanisms.

Advances in research on biomarkers associated with acute myocardial infarction: A review

Acute myocardial infarction (AMI), the most severe cardiovascular event in clinical settings, imposes a significant burden with its annual increase in morbidity and mortality rates. However, it is noteworthy that mortality due to AMI in developed countries has experienced a decline, largely attributable to the advancements in medical interventions such as percutaneous coronary intervention. This trend highlights the importance of accurate diagnosis and effective treatment to preserve the myocardium at risk and improve patient outcomes. Conventional biomarkers such as myoglobin, creatine kinase isoenzymes, and troponin have been instrumental in the diagnosis of AMI. However, recent years have witnessed the emergence of new biomarkers demonstrating the potential to further enhance the accuracy of AMI diagnosis. This literature review focuses on the recent advancements in biomarker research in the context of AMI diagnosis.

Decreased plasma miR-140-3p is associated with coronary artery disease

Background

Although many circulating miRNAs (c-miRNAs) are associated with coronary artery disease (CAD), they are far from being the biomarker for CAD diagnosis or risk prediction. Therefore, novel c-miRNAs discovery and validation are still required, especially evaluating their prediction capacity.

Objectives

Identify novel CAD-related c-miRNAs and evaluate its risk prediction capacity for CAD. Methods: miRNAs associated with CAD were preliminarily investigated in three paired samples representing pre-CAD stage and CAD stage of three female individuals using the Applied Biosystems miRNA TaqMan® Low-Density Array (TLDA). Then, the candidate miRNAs were further verified in an independent case-control study including 129 CAD patients and 76 controls, and their potential practical value in prediction for CAD was evaluated using a machine learning (ML) algorithm. The accuracy of classification and prediction was assessed with the area under the receiver operating characteristic curve (AUC).

Results

TLDA analysis shows that miR-140-3p decreased significantly in CAD-stage (FC = -3.01, P = 0.007). Further study shows that miR-140-3p was significantly lower in CAD group [1.26 (0.68, 2.01)] than in control group [2.07 (1.19, 3.21)] (P < 0.001) and independently associated with CAD (P < 0.001). The addition of miR-140-3p to the variables including smoking history, HDL-c, and APOA1 improved the accuracy of classification by logistic regression and of prediction for CAD by ML models. The ML models built with miR-140-3p and HDL-c, respectively, had a similar prediction accuracy. The feature importance of miR-140-3p and HDL-c in the ML models was also similar. Decision curve analysis showed that miR-140-3p and HDL-c had almost identical net benefits.

Conclusion

Reduced levels of miR-140-3p is linked to CAD, and it is possible to use the plasma level of miR-140-3p as a means of evaluating the risk of CAD.

Platelet Function and Maturity and Related microRNA Expression in Whole Blood in Patients with ST-Segment Elevation Myocardial Infarction

BACKGROUND

 Reduced effect of antiplatelet therapy has been reported in patients with ST-segment elevation myocardial infarction (STEMI). MicroRNAs (miRs) may influence platelet function and maturity, and subsequently the effect of antiplatelet therapy.

OBJECTIVES

 We aimed to explore the association between miR expression and platelet function and maturity in patients with acute STEMI and healthy individuals.

METHODS

 We performed an observational study of STEMI patients admitted directly to primary percutaneous coronary intervention. Patients were treated with antiplatelet therapy according to guidelines. Within 24 hours after admission, blood samples were obtained to measure: the expression of 10 candidate miRs, platelet function markers using advanced flow cytometry, platelet aggregation, serum thromboxane B2, and platelet maturity markers. Furthermore, blood samples from healthy individuals were obtained to determine the normal variation.

RESULTS

 In total, 61 STEMI patients and 50 healthy individuals were included. STEMI patients had higher expression of miR-21-5p, miR-26b-5p, and miR-223-3p and lower expression of miR-150-5p, miR423-5p, and miR-1180-3p than healthy individuals. In STEMI patients, the expression of miR-26b-5p showed the most consistent association with platelet function (all p-values <0.05, Spearman's rho ranging from 0.27 to 0.41), while the expression of miR-150-5p and miR-223-3p showed negative associations with platelet function. No association between miR expression and platelet maturity markers was observed.

CONCLUSION

 In patients with STEMI, the expression of six miRs was significantly different from healthy individuals. The expression of miR-26b-5p may affect platelet function in acute STEMI patients and potentially influence the effect of antiplatelet therapy.

Aerobic exercise protects MI heart through miR-133a-3p downregulation of connective tissue growth factor

OBJECTIVE

To investigate the effect of aerobic exercise intervention to inhibit cardiomyocyte apoptosis and thus improve cardiac function in myocardial infarction (MI) mice by regulating CTGF expression through miR-133a-3p.

METHODS

Male C57/BL6 mice, 7-8 weeks old, were randomly divided into sham-operated group (S group), sham-operated +aerobic exercise group (SE group), myocardial infarction group (MI group) and MI + aerobic exercise group (ME group). The mice were anesthetized the day after training and cardiac function was assessed by cardiac echocardiography. Myocardial collagen volume fraction (CVF%) was analyzed by Masson staining. Myocardial CTGF, Bax and Bcl-2 were detected by Western blotting, and myocardial miR-133a-3p was measured by RT-qPCR.

RESULTS

Compared with the S group, miR-133a-3p, Bcl-2 and EF were significantly decreased and CTGF, Bax, Bax/ Bcl-2, Caspase 3, Cleaved Caspase-3, LVIDd, LVIDs and CVF were significantly increased in the MI group. Compared with the MI group, miR-133a-3p, Bcl-2 and EF were significantly increased, cardiac function was significantly improved, and CTGF, Bax, Bax/ Bcl-2, Caspase 3, Cleaved Caspase-3, LVIDd, LVIDs and CVF were significantly decreased in ME group. The miR-133a-3p was significantly lower and CTGF was significantly higher in the H2O2 intervention group compared with the control group of H9C2 rat cardiomyocytes. miR-133a-3p was significantly higher and CTGF was significantly lower in the AICAR intervention group compared to the H2O2 intervention group. Compared with the control group of H9C2 rat cardiomyocytes, CTGF, Bax and Bax/Bcl-2 were significantly increased and Bcl-2 was significantly decreased in the miR-133a-3p inhibitor intervention group; CTGF, Bax and Bax/Bcl-2 were significantly decreased and Bcl-2 was significantly upregulated in the miR-133a-3p mimics intervention group.

CONCLUSION

Aerobic exercise down-regulated CTGF expression in MI mouse myocardium through miR-133a-3p, thereby inhibiting cardiomyocyte apoptosis and improving cardiac function.

CVD phenotyping in oncologic disorders: cardio-miRNAs as a potential target to improve individual outcomes in revers cardio-oncology

With the increase of aging population and prevalence of obesity, the incidence of cardiovascular disease (CVD) and cancer has also presented an increasing tendency. These two different diseases, which share some common risk factors. Relevant studies in the field of reversing Cardio-Oncology have shown that the phenotype of CVD has a significant adverse effect on tumor prognosis, which is mainly manifested by a positive correlation between CVD and malignant progression of concomitant tumors. This distal crosstalk and the link between different diseases makes us aware of the importance of diagnosis, prediction, management and personalized treatment of systemic diseases. The circulatory system bridges the interaction between CVD and cancer, which suggests that we need to fully consider the systemic and holistic characteristics of these two diseases in the process of clinical treatment. The circulating exosome-miRNAs has been intrinsically associated with CVD -related regulation, which has become one of the focuses on clinical and basic research (as biomarker). The changes in the expression profiles of cardiovascular disease-associated miRNAs (Cardio-miRNAs) may adversely affect concomitant tumors. In this article, we sorted and screened CVD and tumor-related miRNA data based on literature, then summarized their commonalities and characteristics (several important pathways), and further discussed the conclusions of Cardio-Oncology related experimental studies. We take a holistic approach to considering CVD as a risk factor for tumor malignancy, which provides an in-depth analysis of the various regulatory mechanisms or pathways involved in the dual attribute miRNAs (Cardio-/Onco-miRNAs). These mechanisms will be key to revealing the systemic effects of CVD on tumors and highlight the holistic nature of different diseases. Therefore, the Cardio-miRNAs should be given great attention from researchers in the field of CVD and tumors, which might become new targets for tumor treatment. Meanwhile, based on the principles of precision medicine (such as the predictive preventive personalized medicine, 3PM) and reverse Cardio-oncology to better improve individual outcomes, we should consider developing personalized medicine and systemic therapy for cancer from the perspective of protecting cardiovascular function.

Phenome-wide association study on miRNA-related sequence variants: the UK Biobank

BACKGROUND

Genetic variants in the coding region could directly affect the structure and expression levels of genes and proteins. However, the importance of variants in the non-coding region, such as microRNAs (miRNAs), remain to be elucidated. Genetic variants in miRNA-related sequences could affect their biogenesis or functionality and ultimately affect disease risk. Yet, their implications and pleiotropic effects on many clinical conditions remain unknown.

METHODS

Here, we utilised genotyping and hospital records data in the UK Biobank (N = 423,419) to investigate associations between 346 genetic variants in miRNA-related sequences and a wide range of clinical diagnoses through phenome-wide association studies. Further, we tested whether changes in blood miRNA expression levels could affect disease risk through colocalisation and Mendelian randomisation analysis.

RESULTS

We identified 122 associations for six variants in the seed region of miRNAs, nine variants in the mature region of miRNAs, and 27 variants in the precursor miRNAs. These included associations with hypertension, dyslipidaemia, immune-related disorders, and others. Nineteen miRNAs were associated with multiple diagnoses, with six of them associated with multiple disease categories. The strongest association was reported between rs4285314 in the precursor of miR-3135b and celiac disease risk (odds ratio (OR) per effect allele increase = 0.37, P = 1.8 × 10-162). Colocalisation and Mendelian randomisation analysis highlighted potential causal role of miR-6891-3p in dyslipidaemia.

CONCLUSIONS

Our study demonstrates the pleiotropic effect of miRNAs and offers insights to their possible clinical importance.

The Roles of microRNAs in the Cardiovascular System

The discovery of miRNAs and their role in disease represent a significant breakthrough that has stimulated and propelled research on miRNAs as targets for diagnosis and therapy. Cardiovascular disease is an area where the restrictions of early diagnosis and conventional pharmacotherapy are evident and deserve attention. Therefore, miRNA-based drugs have significant potential for development. Research and its application can make considerable progress, as seen in preclinical and clinical trials. The use of miRNAs is still experimental but has a promising role in diagnosing and predicting a variety of acute coronary syndrome presentations. Its use, either alone or in combination with currently available biomarkers, might be adopted soon, particularly if there is diagnostic ambiguity. In this review, we examine the current understanding of miRNAs as possible targets for diagnosis and treatment in the cardiovascular system. We report on recent advances in recognising and characterising miRNAs with a focus on clinical translation. The latest challenges and perspectives towards clinical application are discussed.

Unlocking the potential of microRNAs: machine learning identifies key biomarkers for myocardial infarction diagnosis

BACKGROUND

MicroRNAs (miRNAs) play a crucial role in regulating adaptive and maladaptive responses in cardiovascular diseases, making them attractive targets for potential biomarkers. However, their potential as novel biomarkers for diagnosing cardiovascular diseases requires systematic evaluation.

METHODS

In this study, we aimed to identify a key set of miRNA biomarkers using integrated bioinformatics and machine learning analysis. We combined and analyzed three gene expression datasets from the Gene Expression Omnibus (GEO) database, which contains peripheral blood mononuclear cell (PBMC) samples from individuals with myocardial infarction (MI), stable coronary artery disease (CAD), and healthy individuals. Additionally, we selected a set of miRNAs based on their area under the receiver operating characteristic curve (AUC-ROC) for separating the CAD and MI samples. We designed a two-layer architecture for sample classification, in which the first layer isolates healthy samples from unhealthy samples, and the second layer classifies stable CAD and MI samples. We trained different machine learning models using both biomarker sets and evaluated their performance on a test set.

RESULTS

We identified hsa-miR-21-3p, hsa-miR-186-5p, and hsa-miR-32-3p as the differentially expressed miRNAs, and a set including hsa-miR-186-5p, hsa-miR-21-3p, hsa-miR-197-5p, hsa-miR-29a-5p, and hsa-miR-296-5p as the optimum set of miRNAs selected by their AUC-ROC. Both biomarker sets could distinguish healthy from not-healthy samples with complete accuracy. The best performance for the classification of CAD and MI was achieved with an SVM model trained using the biomarker set selected by AUC-ROC, with an AUC-ROC of 0.96 and an accuracy of 0.94 on the test data.

CONCLUSIONS

Our study demonstrated that miRNA signatures derived from PBMCs could serve as valuable novel biomarkers for cardiovascular diseases.

Blood-Based and Imaging Biomarkers of Atherosclerosis

Atherosclerosis is the main cause of arterial thrombosis, causing acute occlusive cardiovascular syndromes. Numerous risk prediction models have been developed, which mathematically combine multiple predictors, to estimate the risk of developing cardiovascular events. Current risk models typically do not include information from biomarkers that can potentially improve these existing prediction models especially if they are pathophysiologically relevant. Numerous cardiovascular disease biomarkers have been investigated that have focused on known pathophysiological pathways including those related to cardiac stress, inflammation, matrix remodelling, and endothelial dysfunction. Imaging biomarkers have also been studied that have yielded promising results with a potential higher degree of clinical applicability in detection of atherosclerosis and cardiovascular event prediction. To further improve therapy decision-making and guidance, there is continuing intense research on emerging biologically relevant biomarkers. As the pathogenesis of cardiovascular disease is multifactorial, improvements in discrimination and reclassification in risk prediction models will likely involve multiple biomarkers. This article will provide an overview of the literature on potential blood-based and imaging biomarkers of atherosclerosis studied so far, as well as potential future directions.

Study protocol for the epigenetic characterization of angor pectoris according to the affected coronary compartment: Global and comprehensive assessment of the relationship between invasive coronary physiology and microRNAs

BACKGROUND

MicroRNAs (miRNAs) are noncoding RNAs involved in post-transcriptional genetic regulation with a proposed role in intercellular communication. miRNAs are considered promising biomarkers in ischemic heart disease. Invasive physiological evaluation allows a precise assessment of each affected coronary compartment. Although some studies have associated the expression of circulating miRNAs with invasive physiological indexes, their global relationship with coronary compartments has not been assessed. Here, we will evaluate circulating miRNAs profiles according to the coronary pattern of the vascular compartment affectation.

STUDY AND DESIGN

This is an investigator-initiated, multicentre, descriptive study to be conducted at three centres in Spain (NCT05374694). The study will include one hundred consecutive patients older than 18 years with chest pain of presumed coronary cause undergoing invasive physiological evaluation, including fractional flow reserve (FFR) and index of microvascular resistance (IMR). Patients will be initially classified into four groups, according to FFR and IMR: macrovascular and microvascular affectation (FFR≤0.80 / IMR≥25), isolated macrovascular affectation (FFR≤0.80 / IMR<25), isolated microvascular affectation (FFR>0.80 / IMR ≥25) and normal coronary indexes (FFR>0.80 / IMR<25). Patients with isolated microvascular affectation or normal indexes will also undergo the acetylcholine test and may be reclassified as a fifth group in the presence of spasm. A panel of miRNAs previously associated with molecular mechanisms linked to chronic coronary syndrome will be analysed using RT-qPCR.

CONCLUSIONS

The results of this study will identify miRNA profiles associated with patterns of coronary affectation and will contribute to a better understanding of the mechanistic pathways of coronary pathology.

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.

Expression Patterns of MiR-125a and MiR-223 and Their Association with Diabetes Mellitus and Survival in Patients with Non-ST-Segment Elevation Acute Coronary Syndrome

Background: MicroRNAs (miRNA, miR) are small, non-coding RNAs which have become increasingly relevant as diagnostic and prognostic biomarkers. The objective of this study was the investigation of blood-derived miRNAs and their link to long-term all-cause mortality in patients who suffered from non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Methods: This study was an observational prospective study, which included 109 patients with NSTE-ACS. Analysis of the expression of miR-125a and miR-223 was conducted by polymerase chain reaction (PCR). The follow-up period comprised a median of 7.5 years. Long-term all-cause mortality was considered as the primary endpoint. Adjusted Cox-regression analysis was performed for prediction of events. Results: Increased expression of miR-223 (>7.1) at the time point of the event was related to improved long-term all-cause survival (adjusted (adj.) hazard ratio (HR) = 0.09, 95% confidence interval (95%CI): 0.01-0.75; p = 0.026). The receiver operating characteristic (ROC) analysis provided sufficient c-statistics (area under the curve (AUC) = 0.73, 95%CI: 0.58-0.86; p = 0.034; negative predictive value of 98%) for miR-223 to predict long-term all-cause survival. The Kaplan-Meier time to event analysis showed a separation of the survival curves between the groups at an early stage (log rank p = 0.015). Higher plasma miR-125a levels were found in patients with diabetes mellitus vs. in those without (p = 0.010). Furthermore, increased miR-125a expression was associated with an elevated HbA1c concentration. Conclusions: In this hypothesis-generating study, higher values of miR-223 were related to improved long-term survival in patients after NSTE-ACS. Larger studies are required in order to evaluate whether miR-223 can be used as a suitable predictor for long-term all-cause mortality.

Expression profiling analysis reveals key microRNA-mRNA interactions in patients with transposition of the great arteries and systemic left and right ventricles

Background

Patients with transposition of the great arteries (TGA) have different connected systemic chambers and this determines the long-term morbidities and survival. Limited findings have been reported to systematically identify miRNA and mRNA expression levels in such cohorts of patients. In this study, we aimed to characterize miRNAs, mRNAs, and miRNA-mRNA interaction networks in patients with TGA, with a systemic left (LV) and right ventricle (RV).

Materials and methods

Large panel of human miRNA and mRNA microarrays were conducted to determine the genome-wide expression profiles in the blood of 16 TGA-RV patients, 16 TGA-LV patients, and 16 age and gender-matched controls. Using real-time quantitative PCR (RT-qPCR), the differential expression level of a single miRNA was validated. Enrichment analyses of altered miRNA and mRNA expression levels were identified using bioinformatics tools.

Results

Altered miRNA and mRNA expression levels were observed between TGA-RV and TGA-LV patients, together or separated, compared to controls. Among the deregulated miRNAs and mRNAs, 39 and 101 miRNAs were identified as significantly differentially expressed in patients with TGA (both TGA-RV and TGA-LV) and TGA-RV, when compared to matched controls. Furthermore, 51 miRNAs were identified as significantly differentially expressed in patients with TGA-RV when compared to patients with TGA-LV. RT-qPCR relative expression level was highly consistent with microarray analysis results. Similarly, 36 and 164 mRNAs were identified as significantly differentially expressed in patients with TGA (both TGA-RV and TGA-LV) and TGA-RV, when compared to matched controls. Additionally, miR-140-3p showed a higher expression level in patients with overt heart failure (FC = 1.54; P = 0.001) and miR-502-3p showed a higher expression level in patients died due to cardiac death (FC = 1.41; P = 0.011). Integrative analysis resulted in 21 and 23 target genes with higher and lower expression levels, respectively (r ≥ 0.50 and P < 0.05). These target genes (i.e., 21 and 23 target genes) showed an inverse direction of regulation with miRNA and exhibited a miRNA binding site position within the 3'UTR of the target gene.

Conclusion

Our findings provide new insights into a potential molecular biomarker(s) for patients with TGA that may guide better risk stratification and the development of novel targeting therapies. Future studies are needed to investigate the potential significance of miRNAs and mRNAs in TGA-related cardiovascular diseases.

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.

Framework and Spherical Nucleic Acids Synergistically Enhanced Electrochemiluminescence Nanosensors for Rapidly Diagnosing Acute Myocardial Infarction Based on Circulating MicroRNA Levels

Acute myocardial infarction (AMI)-related microRNAs (miRNAs) in circulating blood have been proved as promising biomarkers for AMI diagnosis. The detection of these miRNAs at ultralow levels usually requires nucleic acid amplification strategies to improve the sensitivity at the cost of time. Given that the first hour after an AMI attack is the golden time for saving AMI patients' lives, shortening the time of ultrasensitive miRNA analysis is of great significance for clinical AMI diagnosis. Toward this goal, here we present a direct electrochemiluminescence (ECL) sensing strategy for fast and ultrasensitive miRNA detection, circumventing the time-consuming signal amplification steps. Target miRNAs are directly hybridized with two probe strands that are attached to a covalently hemin-modified spherical nucleic acid enzyme (SNAzyme) and a truncated triangular pyramid DNA nanoplatform on the electrode, respectively. Both of them improve the ECL signal and meanwhile reduce the background, thereby remarkably promoting the detection sensitivity of target miRNAs. It enables the rapid detection of an AMI-related miRNA (miR-499) at 10 aM in human serum within 30 min using the SNAzyme-catalyzed luminol-H₂O₂ ECL reaction. This sensing strategy is then utilized for AMI diagnosis via probing endogenous miR-499 in patients' circulating blood with endogenous miR-16 as an intrinsic reference, showing a significant difference (P < 0.001) between the miR-499 levels of patients and the healthy.

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.

Protective role of small extracellular vesicles derived from HUVECs treated with AGEs in diabetic vascular calcification

The pathogenesis of vascular calcification in diabetic patients remains elusive. As an effective information transmitter, small extracellular vesicles (sEVs) carry abundant microRNAs (miRNAs) that regulate the physiological and pathological states of recipient cells. In the present study, significant up-regulation of miR-126-5p was observed in sEVs isolated from human umbilical vein endothelial cells (HUVECs) stimulated with advanced glycation end-products (A-EC/sEVs). Intriguingly, these sEVs suppressed the osteogenic differentiation of vascular smooth muscle cells (VSMCs) by targeting BMPR1B, which encodes the receptor for BMP, thereby blocking the smad1/5/9 signalling pathway. In addition, knocking down miR-126-5p in HUVECs significantly diminished the anti-calcification effect of A-EC/sEVs in a mouse model of type 2 diabetes. Overall, miR-126-5p is highly enriched in sEVs derived from AGEs stimulated HUVECs and can target BMPR1B to negatively regulate the trans-differentiation of VSMCs both in vitro and in vivo.

Extraction-Free Absolute Quantification of Circulating miRNAs by Chip-Based Digital PCR

Circulating microRNAs (miRNA) have been proposed as specific biomarkers for several diseases. Quantitative Real-Time PCR (RT-qPCR) is the gold standard technique currently used to evaluate miRNAs expression from different sources. In the last few years, digital PCR (dPCR) emerged as a complementary and accurate detection method. When dealing with gene expression, the first and most delicate step is nucleic-acid isolation. However, all currently available protocols for RNA extraction suffer from the variable loss of RNA species due to the chemicals and number of steps involved, from sample lysis to nucleic acid elution. Here, we evaluated a new process for the detection of circulating miRNAs, consisting of sample lysis followed by direct evaluation by dPCR in plasma from healthy donors and in the cardiovascular setting. Our results showed that dPCR is able to detect, with high accuracy, low-copy-number as well as highly expressed miRNAs in human plasma samples without the need for RNA extraction. Moreover, we assessed a known myocardial infarction-related miR-133a in acute myocardial infarct patients vs. healthy subjects. In conclusion, our results show the suitability of the extraction-free quantification of circulating miRNAs as disease markers by direct dPCR.

MicroRNAs as therapeutic targets in cardiovascular disease

The discovery of microRNAs and their role in diseases was a breakthrough that inspired research into microRNAs as drug targets. Cardiovascular diseases are an area in which limitations of conventional pharmacotherapy are highly apparent and where microRNA-based drugs have appreciably progressed into preclinical and clinical testing. In this Review, we summarize the current state of microRNAs as therapeutic targets in the cardiovascular system. We report recent advances in the identification and characterization of microRNAs, their manipulation and clinical translation, and discuss challenges and perspectives toward clinical application.

Implication of microRNA as a potential biomarker of myocarditis

Myocarditis was previously attributed to an epidemic viral infection. Additional harmful reagents, in addition to viruses, play a role in its etiology. Coronavirus disease 2019 (COVID-19) vaccine-induced myocarditis has recently been described, drawing attention to vaccine-induced myocarditis in children and adolescents. Its pathology is based on a series of complex immune responses, including initial innate immune responses in response to viral entry, adaptive immune responses leading to the development of antigen-specific antibodies, and autoimmune responses to cellular injury caused by cardiomyocyte rupture that releases antigens. Chronic inflammation and fibrosis in the myocardium eventually result in cardiac failure. Recent advancements in molecular biology have remarkably increased our understanding of myocarditis. In particular, microRNAs (miRNAs) are a hot topic in terms of the role of new biomarkers and the pathophysiology of myocarditis. Myocarditis has been linked with microRNA-221/222 (miR-221/222), miR-155, miR-10a*, and miR-590. Despite the lack of clinical trials of miRNA intervention in myocarditis yet, multiple clinical trials of miRNAs in other cardiac diseases have been aggressively conducted to help pave the way for future research, which is bolstered by the success of recently U.S. Food and Drug Administration-approved small-RNA medications. This review presents basic information and recent research that focuses on myocarditis and related miRNAs as a potential novel biomarker and the therapeutics.

Genetic Variants of MIR27A, MIR196A2 May Impact the Risk for the Onset of Coronary Artery Disease in the Pakistani Population

Genetic variants in microRNA genes have a detrimental effect on miRNA-mediated regulation of gene expression and may contribute to coronary artery disease (CAD). CAD is the primary cause of mortality worldwide. Several environmental, genetic, and epigenetic factors are responsible for CAD susceptibility. The contribution of protein-coding genes is extensively studied. However, the role of microRNA genes in CAD is at infancy. The study is aimed to investigate the impact of rs895819, rs11614913, and rs2168518 variants in MIR27A, MIR196A2, and MIR4513, respectively, in CAD using allele-specific PCR. Results: For variant rs11614913, significant distribution of the genotypes among the cases and controls was determined by co-dominant [χ² = 54.4; p value ≤ 0.0001], dominant (C/C vs. C/T + T/T) [OR = 0.257 (0.133-0.496); p value ≤ 0.0001], recessive (T/T vs. C/T + C/C) [OR = 1.56 (0.677-0.632); p value = 0.398], and additive models [OR = 0.421 (0.262-0.675); p value = 0.0004]. Similarly, a significant association of rs895819 was determined by co-dominant [χ² = 9.669; p value ≤ 0.008], dominant (A/A vs. A/G + G/G) [OR = 0.285 (0.1242-0.6575); p value ≤ 0.0034], recessive (G/G vs. A/G + A/A) [OR = 0.900 (0.3202-3.519); p value = 1.000], and additive models [OR = 0.604 (0.3640-1.002); p value = 0.05] while no significant association of rs2168518 with CAD was found. Conclusion: The variants rs895819 and rs11614913 are the susceptibility factors for CAD.

Non-canonical features of microRNAs: paradigms emerging from cardiovascular disease

Research showing that microRNAs (miRNAs) are versatile regulators of gene expression has instigated tremendous interest in cardiovascular research. The overwhelming majority of studies are predicated on the dogmatic notion that miRNAs regulate the expression of specific target mRNAs by inhibiting mRNA translation or promoting mRNA decay in the RNA-induced silencing complex (RISC). These efforts mostly identified and dissected contributions of multiple regulatory networks of miRNA-target mRNAs to cardiovascular pathogenesis. However, evidence from studies in the past decade indicates that miRNAs also operate beyond this canonical paradigm, featuring non-conventional regulatory functions and cellular localizations that have a pathophysiological role in cardiovascular disease. In this Review, we highlight the functional relevance of atypical miRNA biogenesis and localization as well as RISC heterogeneity. Moreover, we delineate remarkable non-canonical examples of miRNA functionality, including direct interactions with proteins beyond the Argonaute family and their role in transcriptional regulation in the nucleus and in mitochondria. We scrutinize the relevance of non-conventional biogenesis and non-canonical functions of miRNAs in cardiovascular homeostasis and pathology, and contextualize how uncovering these non-conventional properties can expand the scope of translational research in the cardiovascular field and beyond.

Circulating MicroRNAs as Novel Biomarkers in Risk Assessment and Prognosis of Coronary Artery Disease

Coronary artery disease is among the leading causes of death worldwide. Nevertheless, available cardiovascular risk prediction algorithms still miss a significant portion of individuals at-risk. Thus, the search for novel non-invasive biomarkers to refine cardiovascular risk assessment is both an urgent need and an attractive topic, which may lead to a more accurate risk stratification and/or prognostic score definition for coronary artery disease. A new class of such non-invasive biomarkers is represented by extracellular microRNAs (miRNAs) circulating in the blood. MiRNAs are non-coding RNA of 22–25 nucleotides in length that play a significant role in both cardiovascular physiology and pathophysiology. Given their high stability and conservation, resistance to degradative enzymes, and detectability in body fluids, circulating miRNAs are promising emerging biomarkers, and specific expression patterns have already been associated with a wide range of cardiovascular conditions. In this review, an overview of the role of blood miRNAs in risk assessment and prognosis of coronary artery disease is given.

Multilayer control of cardiac electrophysiology by microRNAs

The electrophysiological properties of the heart include cardiac automaticity, excitation (i.e., depolarization and repolarization of action potential) of individual cardiomyocytes, and highly coordinated electrical propagation through the whole heart. An abnormality in any of these properties can cause arrhythmias. MicroRNAs (miRs) have been recognized as essential regulators of gene expression through the conventional RNA interference (RNAi) mechanism and are involved in a variety of biological events. Recent evidence has demonstrated that miRs regulate the electrophysiology of the heart through fine regulation by the conventional RNAi mechanism of the expression of ion channels, transporters, intracellular Ca²⁺-handling proteins, and other relevant factors. Recently, a direct interaction between miRs and ion channels has also been reported in the heart, revealing a biophysical modulation by miRs of cardiac electrophysiology. These advanced discoveries suggest that miR controls cardiac electrophysiology through two distinct mechanisms: immediate action through biophysical modulation and long-term conventional RNAi regulation. Here, we review the recent research progress and summarize the current understanding of how miR manipulates the function of ion channels to maintain the homeostasis of cardiac electrophysiology.

Associations between circulating microRNAs and coronary plaque characteristics: potential impact from physical exercise

Background and aims MicroRNAs (miRs) are involved in different steps in the development of atherosclerosis and are proposed as promising biomarkers of coronary artery disease (CAD). We hypothesized that circulating levels of miRs were associated with coronary plaque components assessed by radiofrequency intravascular ultrasound (RF-IVUS) before and after aerobic exercise intervention. Methods 31 patients with CAD treated with percutaneous coronary intervention (PCI) previously included in a randomized trial with aerobic interval training (AIT) or moderate continuous training (MCT) as post-PCI intervention were included. Coronary plaque characteristics by grayscale and RF-IVUS and predefined circulating candidate miRs in plasma were analysed at baseline and follow-up. Associations between miRs and coronary plaque composition, and the potential effect from exercise, were analysed using linear regression. Results Circulating levels of miR-15a-5p, miR-30e-5p, miR-92a-3p, miR-199a-3p, miR-221-3p, and miR-222-3p were associated with baseline coronary necrotic core volume. Following exercise intervention, decreased levels of miR-15a-5p, miR-93-5p, and miR-451a, and increased levels of miR-146a-5p were associated with an observed regression of coronary plaque burden. A mirPath prediction tool identified that genes regulated by miR-15a-5p, miR-199a-3p, and miR-30e-5p were significantly overrepresented in pathways related to fatty acid biosynthesis and fatty acid metabolism. Conclusion This exploratory study demonstrated six miRs associated with coronary necrotic core, a marker of plaque vulnerability. In addition, changes in four miRs were associated with a regression of coronary plaque burden following exercise intervention. These novel findings may identify potential future biomarkers of CAD and coronary plaque composition.

Functional Interactions Between lncRNAs/circRNAs and miRNAs: Insights Into Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases that affect synovitis, bone, cartilage, and joint. RA leads to bone and cartilage damage and extra-articular disorders. However, the pathogenesis of RA is still unclear, and the lack of effective early diagnosis and treatment causes severe disability, and ultimately, early death. Accumulating evidence revealed that the regulatory network that includes long non-coding RNAs (lncRNAs)/circular RNAs (circRNAs), micro RNAs (miRNAs), and messenger RNAs (mRNA) plays important roles in regulating the pathological and physiological processes in RA. lncRNAs/circRNAs act as the miRNA sponge and competitively bind to miRNA to regulate the expression mRNA in synovial tissue, FLS, and PBMC, participate in the regulation of proliferation, apoptosis, invasion, and inflammatory response. Thereby providing new strategies for its diagnosis and treatment. In this review, we comprehensively summarized the regulatory mechanisms of lncRNA/circRNA-miRNA-mRNA network and the potential roles of non-coding RNAs as biomarkers and therapeutic targets for the diagnosis and treatment of RA.

Association of fasting blood glucose to high-density lipoprotein cholesterol ratio with short-term outcomes in patients with acute coronary syndrome

Background

Biochemical markers are crucial for determining risk in coronary artery disease (CAD) patients; however, the relationship between fasting blood glucose to high-density lipoprotein cholesterol (FG/HDL-C) ratio and short-term outcomes in acute coronary syndrome (ACS) patients remains unknown. Therefore, we have investigated the relationship between the FG/HDL-C ratio and short-term outcomes in ACS patients.

Methods

We used data from a pragmatic, stepped-wedge, cluster-randomized clinical trial to perform a post hoc analysis. A total of 11,284 individuals with ACS were subdivided into quartiles according to their FG/HDL-C ratios. We used a multivariate logistic regression model, two-piecewise linear regression model, and generalized additive model (GAM) to evaluate the relationship between the FG/HDL-C ratio and short-term outcomes (major adverse cardiovascular events [MACEs] and cardiovascular [CV] death within 30 days).

Results

The FG/HDL-C ratio was remarkably linked to an enhanced risk of MACEs and CV death in individuals with ACS in the highest quartile (MACEs, odds ratio [OR]: 1.49; 95% confidence interval [CI], [1.11, 1.99]; P < 0.01; CV death, OR: 1.69; 95% CI, [1.01, 1.41]; P = 0.04). The GAM suggested that the relationship between the FG/HDL-C ratio and MACEs and CV death was non-linear. The two-piecewise linear regression model demonstrated that the threshold values were 3.02 and 3.00 for MACEs and CV death, respectively.

Conclusions

A higher FG/HDL-C ratio is associated with a higher risk of MACEs and CV death in patients with ACS.

Circulating miR-21-5p, miR-146a-5p, miR-320a-3p in patients with atrial fibrillation in combination with hypertension and coronary artery disease

Aim. To study the plasma profiles of circulating extracellular microribonucleic acids (miRNAs), potentially including in pathogenesis of cardiovascular diseases, in patients with atrial fibrillation (AF) in combination with hypertension (HTN) or coronary artery disease (CAD).

Material and methods. The study included patients with AF in combi  nation with HTN (n=21) or CAD (n=10), as well as following control groups: patients with uncomplicated HTN without AF (n=28), patients with stable CAD without AF (n=10) and healthy individuals (n=30). MiRNA samples were isolated from blood plasma of the study participants. MiRNAs were detected by TaqMan quantitative polymerase chain reaction assay. The relative plasma levels of five candidate miRNAs were estimated relative to the reference miR-16-5p.

Results. Among the analyzed circulating plasma miRNAs, a higher level of miR-320a-3p was associated with AF, while increased levels of miR 146a-5p and miR-21-5p are potentially associated with presence of both AF and CAD.

Conclusion. Differences were found in the plasma miRNA profiles (miR-21-5p, miR-320a-3p, miR-146a-5p) between patients with AF, regardless of concomitant disease (CAD or HTN), and healthy individuals in the control group.

Research on the Health Literacy Status and Compliance Behavior of Patients with Acute Coronary Syndrome

This study is aimed at assessing the current status of ACS patients' health literacy and medication compliance, analyzing the relationship between the two, and providing ideas for clinically improving the medication compliance of ACS patients and preventing the recurrence of cardiovascular events. ACS patients need long-term medication to prevent vascular restenosis after surgery, and bad living habits and mood swings will affect postoperative recovery, so clinical interventions are needed to help patients establish a healthy lifestyle. The effect of conventional care is not ideal. Therefore, this paper uses regression analysis to analyze the correlation between the health literacy status of ACS patients and the compliance behavior, combines the investigation and experiment to perform regression analysis and uses mathematical statistics to process data. The connection between health literacy level and compliance behavior is discovered via a study, providing a point of reference for future research.

Levels of miR-130b-5p in peripheral blood are associated with severity of coronary artery disease

BACKGROUND

Although patients with coronary artery disease (CAD) have a high mortality rate, the pathogenesis of CAD is still poorly understood. During the past decade, microRNAs (miRNAs) have emerged as new, potential diagnostic biomarkers in several diseases, including CAD. This study aimed to investigate the expression profiles of miRNAs in individuals with CAD and non-CAD.

METHODS AND RESULTS

The Agilent's microarray analyses were performed to compare the whole blood miRNA profile of selected individuals with severe CAD (n = 12, ≥ 90% stenosis) and non-CAD (n = 12, ≤ 20 stenosis). Expressions of selected differentially expressed miRNAs (DEMs) were analyzed for validation in individuals with critical CAD (n = 50) and non-CAD (n = 43) using real-time PCR. Target prediction tools were utilized to identify miRNA target genes. We identified 6 DEMs that were downregulated in CAD patients, which included hsa-miR-18a-3p and hsa-miR-130b-5p, that were analyzed for further testing. Expression levels of hsa-miR-130b-5p were found negatively correlated with SYNTAX score and stenosis in female CAD patients (p < 0.05). In addition, both miRNAs were found positively correlated with plasma HDL and inversely correlated with fasting triglyceride levels (p < 0.05). In linear regression analysis adjusted for several confounders, the correlations have remained statistically significant. Computational prediction of target genes indicated a relevant role of hsa-miR-130b-5p and hsa-miR-18a-3p in modulating the expression of genes associated with cardiovascular diseases.

CONCLUSION

Our findings highlight a significantly different pattern of miRNA expression in CAD patients in microarray results. Hsa-miR-18a-3p and hsa-miR-130b-5p might serve as biomarkers of CAD development and progression and warrant further attention.

Current Knowledge of MicroRNAs (miRNAs) in Acute Coronary Syndrome (ACS): ST-Elevation Myocardial Infarction (STEMI)

Regardless of the newly diagnostic and therapeutic advances, coronary artery disease (CAD) and more explicitly, ST-elevation myocardial infarction (STEMI), remains one of the leading causes of morbidity and mortality worldwide. Thus, early and prompt diagnosis of cardiac dysfunction is pivotal in STEMI patients for a better prognosis and outcome. In recent years, microRNAs (miRNAs) gained attention as potential biomarkers in myocardial infarction (MI) and acute coronary syndromes (ACS), as they have key roles in heart development, various cardiac processes, and act as indicators of cardiac damage. In this review, we describe the current available knowledge about cardiac miRNAs and their functions, and focus mainly on their potential use as novel circulating diagnostic and prognostic biomarkers in STEMI.

MicroRNA-320a-3p Signatures as a Satisfactory Predictor of Acute Coronary Syndrome and Attenuates Inflammation by Targeting X-Linked Inhibitor of Apoptosis Protein

Acute coronary syndrome (ACS) is a heart disease with a high mortality rate. Recently, more and more evidence illustrated that microRNAs (miRNA) participated in regulating the occurrence of heart disease. This study aimed to detect the level of serum miR-320a-3p in patients with ACS, predict its possibility as a candidate gene for diagnosis, and explore its potential mechanism in the regulation of ACS. 139 ACS patients and 126 controls were recruited in this study. The expression level of miR-320a-3p was determined by qRT-PCR. The predictive value in ACS was assessed by receiver operating characteristic (ROC) curve. Enzyme-linked immunosorbent assay (ELISA) was used to measure the protein expression levels of inflammatory factors. The downstream targets of miR-320a-3p were verified by luciferase reporter gene assay. In ACS patients and rat models, the expression level of serum miR-320a-3p was significantly increased. ROC curve revealed that abnormal expression of miR-320a-3p was of diagnostic value for ACS. In an in vivo rat model, down-regulation of miR-320a-3p inhibited the production of von Willebrand factor (vWF), Heart fatty acid-binding protein (H-FABP), interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α). In other words, down-regulation of miR-320a-3p reduced rat vascular endothelial injury and inflammation. X-linked inhibitor of apoptosis protein (XIAP) was determined to be a direct target of miR-320a-3p. miR-320a-3p is useful for the diagnosis of ACS. Animal experiments confirmed that up-regulated miR-320a-3p promoted vascular endothelial injury and inflammatory response by targeting XIAP, thus promoting the development of ACS. MiR-320a-3p may be a new breakthrough in the diagnosis and treatment of ACS.

Nicotinamide Adenine Dinucleotide Phosphate Oxidases in Glucose Homeostasis and Diabetes-Related Endothelial Cell Dysfunction

Oxidative stress within the vascular endothelium, due to excess generation of reactive oxygen species (ROS), is thought to be fundamental to the initiation and progression of the cardiovascular complications of type 2 diabetes mellitus. The term ROS encompasses a variety of chemical species including superoxide anion (O₂^•-), hydroxyl radical (OH^-) and hydrogen peroxide (H₂O₂). While constitutive generation of low concentrations of ROS are indispensable for normal cellular function, excess O₂^•- can result in irreversible tissue damage. Excess ROS generation is catalysed by xanthine oxidase, uncoupled nitric oxide synthases, the mitochondrial electron transport chain and the nicotinamide adenine dinucleotide phosphate (NADPH) oxidases. Amongst enzymatic sources of O₂^•- the Nox2 isoform of NADPH oxidase is thought to be critical to the oxidative stress found in type 2 diabetes mellitus. In contrast, the transcriptionally regulated Nox4 isoform, which generates H₂O₂, may fulfil a protective role and contribute to normal glucose homeostasis. This review describes the key roles of Nox2 and Nox4, as well as Nox1 and Nox5, in glucose homeostasis, endothelial function and oxidative stress, with a key focus on how they are regulated in health, and dysregulated in type 2 diabetes mellitus.

Cardiomyocyte microvesicles: proinflammatory mediators after myocardial ischemia?

Myocardial infarction is a frequent complication of cardiovascular disease leading to high morbidity and mortality worldwide. Elevated C-reactive protein (CRP) levels after myocardial infarction are associated with heart failure and poor prognosis. Cardiomyocyte microvesicles (CMV) are released during hypoxic conditions and can act as mediators of intercellular communication. MicroRNA (miRNA) are short non-coding RNA which can alter cellular mRNA-translation. Microvesicles (MV) have been shown to contain distinct patterns of miRNA from their parent cells which can affect protein expression in target cells. We hypothesized that miRNA containing CMV mediate hepatic CRP expression after cardiomyocyte hypoxia. H9c2-cells were cultured and murine cardiomyocytes were isolated from whole murine hearts. H9c2- and murine cardiomyocytes were exposed to hypoxic conditions using a hypoxia chamber. Microvesicles were isolated by differential centrifugation and analysed by flow cytometry. Next-generation-sequencing was performed to determine the miRNA-expression profile in H9c2 CMV compared to their parent cells. Microvesicles were incubated with a co-culture model of the liver consisting of THP-1 macrophages and HepG2 cells. IL-6 and CRP expression in the co-culture was assessed by qPCR and ELISA. CMV contain a distinct pattern of miRNA compared to their parent cells including many inflammation-related miRNA. CMV induced IL-6 expression in THP-1 macrophages alone and CRP expression in the hepatic co-culture model. MV from hypoxic cardiomyocytes can mediate CRP expression in a hepatic co-culture model. Further studies will have to show whether these effects are reproducible in-vivo.

Circulating Extracellular miRNA Analysis in Patients with Stable CAD and Acute Coronary Syndromes

Extracellular circulating microRNAs (miRNAs) are currently a focus of interest as non-invasive biomarkers of cardiovascular pathologies, including coronary artery disease (CAD) and acute coronary syndromes (ACS): myocardial infarction with and without ST-segment elevation (STEMI and NSTEMI) and unstable angina (UA). However, the current data for some miRNAs are controversial and inconsistent, probably due to pre-analytical and methodological variances in different studies. In this work, we fulfilled the basic pre-analytical requirements provided for circulating miRNA studies for application to stable CAD and ACS research. We used quantitative PCR to determine the relative plasma levels of eight circulating miRNAs that are potentially associated with atherosclerosis. In a cohort of 136 adult clinic CAD patients and outpatient controls, we found that the plasma levels of miR-21-5p and miR-146a-5p were significantly elevated in ACS patients, and the level of miR-17-5p was decreased in ACS and stable CAD patients compared to both healthy controls and hypertensive patients without CAD. Within the ACS patient group, no differences were found in the plasma levels of these miRNAs between patients with positive and negative troponin, nor were any differences found between STEMI and NSTEMI. Our results indicate that increased plasma levels of miR-146a-5p and miR-21-5p can be considered general ACS circulating biomarkers and that lowered miR-17-5p can be considered a general biomarker of CAD.

Serum Metabolomic Analysis of Coronary Heart Disease Patients with Stable Angina Pectoris Subtyped by Traditional Chinese Medicine Diagnostics Reveals Biomarkers Relevant to Personalized Treatments

To improve the treatment of patients with coronary heart disease (CHD), personalized treatments based on potential biomarkers could make a difference. To investigate if such potential biomarkers could be found for CHD inhomogeneous, we combined traditional Chinese medicine based diagnosis with untargeted and targeted metabolomics analyses. Shi and Xu patient subtype groups of CHD with angina pectoris were identified. Different metabolites including lipids, fatty acids and amino acids were further analyzed with targeted metabolomics and mapped to disease-related pathways. The long-chain unsaturated lipids ceramides metabolism, bile acid metabolism were differentially affected in the Xu subtype groups. While, Shi-subtype patients seemed to show inflammation, anomalous levels of bioactive phospholipids and antioxidant molecules. Furthermore, variations in the endothelial damage response and energy metabolism found based on ELISA analysis are the key divergence points between different CHD subtypes. The results showed Xu subtype patients might benefit from long-chain unsaturated lipids ceramides as therapeutic targets. Shi subtype patients might benefit more from levels of polyunsaturated fatty acid consumption and treatments that help in restoring energy balance. Metabolic differences can be essential for treatment protocols. Thus, patient group specific differences can serve as important information to refine current treatment approaches in a personalized manner.

MicroRNA as Biomarkers for Platelet Function and Maturity in Patients with Cardiovascular Disease

Patients with cardiovascular disease (CVD) are at increased risk of suffering myocardial infarction. Platelets are key players in thrombus formation and, therefore, antiplatelet therapy is crucial in the treatment and prevention of CVD. MicroRNAs (miRs) may hold the potential as biomarkers for platelet function and maturity. This systematic review was conducted using the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). To identify studies investigating the association between miRs and platelet function and maturity in patients with CVD, PubMed and Embase were searched on October 13 and December 13, 2020 without time boundaries. Risk of bias was evaluated using a standardized quality assessment tool. Of the 16 included studies, 6 studies were rated "good" and 10 studies were rated "fair." In total, 45 miRs correlated significantly with platelet function or maturity (rho ranging from -0.68 to 0.38, all p < 0.05) or differed significantly between patients with high platelet reactivity and patients with low platelet reactivity (p-values ranging from 0.0001 to 0.05). Only four miRs were investigated in more than two studies, namely miR-223, miR-126, miR-21 and miR-150. Only one study reported on the association between miRs and platelet maturity. In conclusion, a total of 45 miRs were associated with platelet function or maturity in patients with CVD, with miR-223 and miR-126 being the most frequently investigated. However, the majority of the miRs were only investigated in one study. More data are needed on the potential use of miRs as biomarkers for platelet function and maturity in CVD patients.

A History of Preterm Delivery Is Associated with Aberrant Postpartal MicroRNA Expression Profiles in Mothers with an Absence of Other Pregnancy-Related Complications

This prospective cross-sectional case-control study investigated the postpartal gene expression of microRNAs associated with diabetes/cardiovascular/cerebrovascular diseases in the peripheral white blood cells of women with anamnesis of preterm prelabor rupture of membranes (n = 58), spontaneous preterm birth (n = 55), and term delivery (n = 89) by a quantitative reverse transcription polymerase chain reaction. After pregnancies complicated by preterm prelabor rupture of membranes or spontaneous preterm birth, mothers showed diverse expression profiles for 25 out of 29 tested microRNAs (miR-1-3p, miR-16-5p, miR-17-5p, miR-20a-5p, miR-20b-5p, miR-21-5p, miR-23a-3p, miR-24-3p, miR-26a-5p, miR-29a-3p, miR-100-5p, miR-103a-3p, miR-125b-5p, miR-126-3p, miR-130b-3p, miR-133a-3p, miR-143-3p, miR-145-5p, miR-146a-5p, miR-181a-5p, miR-195-5p, miR-199a-5p, miR-221-3p, miR-499a-5p, and miR-574-3p). The earliest gestational ages at delivery and the lowest birth weights of newborns were associated with the highest postpartal levels of the previously mentioned microRNAs in maternal peripheral white blood cells. Administration of tocolytic drugs in order to prolong pregnancy, used in order to administer and complete a full course of antenatal corticosteroids, was associated with alterations in postpartal microRNA expression profiles to a lesser extent than in women with imminent delivery, where there was insufficient time for administration of tocolytics and antenatal corticosteroids. Overall, mothers who did not receive tocolytic therapy (miR-24-3p and miR-146a-5p) and mothers who did not receive corticosteroid therapy (miR-1-3p, miR-100-5p, and miR-143-3p) had increased or showed a trend toward increased postpartal microRNA expression when compared with mothers given tocolytic and corticosteroid therapy. In addition, mothers with serum C-reactive protein levels above 20 mg/L, who experienced preterm labour, showed a trend toward increased postpartal expression profiles of miR-143-3p and miR-199a-5p when compared with mothers with normal serum C-reactive protein levels. On the other hand, the occurrence of maternal leukocytosis, the presence of intra-amniotic inflammation (higher levels of interleukin 6 in the amniotic fluid), and the administration of antibiotics at the time of preterm delivery had no impact on postpartal microRNA expression profiles in mothers with a history of preterm delivery. Likewise, the condition of the newborns at the moment of birth, determined by Apgar scores at 5 and 10 min and the pH of cord arterial blood, had no influence on the postpartal expression profiles of mothers with a history of preterm delivery. These findings may contribute to explaining the increased cardiovascular risk in mothers with anamnesis of preterm delivery, and the greater increase of maternal cardiovascular risk with the decrease of gestational age at delivery. Women with preterm delivery in their anamnesis represent a high-risk group with special needs on a long-term basis, with a need to apply preventive and therapeutic interventions as early as possible.

Nourin-Dependent miR-137 and miR-106b: Novel Biomarkers for Early Diagnosis of Myocardial Ischemia in Coronary Artery Disease Patients

Background: Although cardiovascular imaging techniques are widely used to diagnose myocardial ischemia in patients with suspected stable coronary artery disease (CAD), they have limitations related to lack of specificity, sensitivity and “late” diagnosis. Additionally, the absence of a simple laboratory test that can detect myocardial ischemia in CAD patients, has led to many patients being first diagnosed at the time of the development of myocardial infarction. Nourin is an early blood-based biomarker rapidly released within five minutes by “reversible” ischemic myocardium before progressing to necrosis. Recently, we demonstrated that the Nourin-dependent miR-137 (marker of cell damage) and miR-106b-5p (marker of inflammation) can diagnose myocardial ischemia in patients with unstable angina (UA) and also stratify severity of ischemia, with higher expression in acute ST-segment elevation myocardial infarction (STEMI) patients compared to UA patients. Minimal baseline-gene expression levels of Nourin miRNAs were detected in healthy subjects. Objectives: To determine: (1) whether Nourin miRNAs are elevated in chest pain patients with myocardial ischemia suspected of CAD, who also underwent dobutamine stress echocardiography (DSE) or ECG/Treadmill stress test, and (2) whether the elevated levels of serum Nourin miRNAs correlate with results of ECHO/ECG stress test in diagnosing CAD patients. Methods: Serum gene expression levels of miR-137, miR-106b-5p and their corresponding molecular pathway network were measured blindly in 70 enrolled subjects using quantitative real time PCR (qPCR). Blood samples were collected from: (1) patients with chest pain suspected of myocardial ischemia (n = 38) both immediately “pre-stress test” and “post-stress test” 30 min. after test termination; (2) patients with acute STEMI (n = 16) functioned as our positive control; and (3) healthy volunteers (n = 16) who, also, exercised on ECG/Treadmill stress test for Nourin baseline-gene expression levels. Results: (1) strong correlation was observed between Nourin miRNAs serum expression levels and results obtained from ECHO/ECG stress test in diagnosing myocardial ischemia in CAD patients; (2) positive “post-stress test” patients with CAD diagnosis showed upregulation of miR-137 by 572-fold and miR-106b-5p by 122-fold, when compared to negative “post-stress test” patients (p < 0.001); (3) similarly, positive “pre-stress test” CAD patients showed upregulation of miR-137 by 1198-fold and miR-106b-5p by 114-fold, when compared to negative “pre-stress test” patients (p < 0.001); and (4) healthy subjects had minimal baseline-gene expressions of Nourin miRNAs. Conclusions: Nourin-dependent miR-137 and miR-106b-5p are promising novel blood-based biomarkers for early diagnosis of myocardial ischemia in chest pain patients suspected of CAD in outpatient clinics. Early identification of CAD patients, while patients are in the stable state before progressing to infarction, is key to providing crucial diagnostic steps and therapy to limit adverse cardiac events, improve patients’ health outcome and save lives.

A critical approach for successful use of circulating microRNAs as biomarkers in cardiovascular diseases: the case of hypertrophic cardiomyopathy

MicroRNAs (miRNAs) are small noncoding RNA molecules that act as major regulators of gene expression at the post-transcriptional level. As the potential applications of miRNAs in the diagnosis and treatment of human diseases have become more evident, many studies of hypertrophic cardiomyopathy (HCM) have focused on the systemic identification and quantification of miRNAs in biofluids and myocardial tissues. HCM is a hereditary cardiomyopathy caused by mutations in genes encoding proteins of the sarcomere. Despite overall improvements in survival, progression to heart failure, stroke, and sudden cardiac death remain prominent features of living with HCM. Several miRNAs have been shown to be promising biomarkers of HCM; however, there are many challenges to ensuring the validity, consistency, and reproducibility of these biomarkers for clinical use. In particular, miRNA testing may be limited by pre-analytical and analytical caveats, making our interpretation of results challenging. Such factors that may affect miRNA testing include sample type selection, hemolysis, platelet activation, and renal dysfunction. Therefore, researchers should be careful when developing appropriate standards for the design of miRNA profiling studies in order to ensure that all results provided are both accurate and reliable. In this review, we discuss the application of miRNAs as biomarkers for HCM.