Clinical impact of circulating miR-26a, miR-191, and miR-208b in plasma of patients with acute myocardial infarction

Analysis of Circulating miRNA Expression Profiles in Type 2 Diabetes Patients with Diabetic Foot Complications

Type 2 diabetes mellitus (T2DM) is associated with various complications, including diabetic foot, which can lead to significant morbidity and mortality. Non-healing foot ulcers in diabetic patients are a major risk factor for infections and amputations. Despite conventional treatments, which have limited efficacy, there is a need for more effective therapies. MicroRNAs (miRs) are small non-coding RNAs that play a role in gene expression and have been implicated in diabetic wound healing. miR expression was analyzed through RT-qPCR in 41 diabetic foot Mexican patients and 50 controls. Diabetic foot patients showed significant increases in plasma levels of miR-17-5p (p = 0.001), miR-191-5p (p = 0.001), let-7e-5p (p = 0.001), and miR-33a-5p (p = 0.005) when compared to controls. Elevated levels of miR-17, miR-191, and miR-121 correlated with higher glucose levels in patients with diabetic foot ulcers (r = 0.30, p = 0.004; r = 0.25, p = 0.01; and r = 0.21, p = 0.05, respectively). Levels of miR-17 showed the highest diagnostic potential (AUC 0.903, p = 0.0001). These findings underscore the possible role of these miRs in developing diabetes complications. Our study suggests that high miR-17, miR-191, and miR-121 expression is strongly associated with higher glucose levels and the development of diabetic foot ulcers.

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.

Serum MicroRNA-191-5p Levels in Vascular Complications of Type 1 Diabetes: The EURODIAB Prospective Complications Study

CONTEXT

MicroRNA-191-5p regulates key cellular processes involved in the pathogenesis of diabetic complications such as angiogenesis, extracellular matrix deposition, and inflammation. However, no data on circulating microRNA-191-5p in the chronic complications of diabetes are available.

OBJECTIVE

To assess whether serum levels of microRNA-191-5p were associated with micro- and macrovascular disease in a large cohort of subjects with type 1 diabetes mellitus (DM1) from the EURODIAB Prospective Complication Study.

DESIGN AND SETTING

Levels of microRNA-191-5p were measured by quantitative PCR in 420 patients with DM1 recruited as part of the cross-sectional analysis of the EURODIAB Prospective Complication Study. Cases (n = 277) were subjects with nephropathy and/or retinopathy and/or cardiovascular disease (CVD). Controls (n = 143) were patients without complications. Logistic regression analysis was performed to evaluate the potential independent association of microRNA-191-5p levels with chronic complications of diabetes.

RESULTS

Levels of microRNA-191-5p were significantly reduced (P < .001) in cases compared with controls even after adjustment for age, sex, and diabetes duration. Logistic regression analysis revealed that microRNA-191-5p was negatively associated with a 58% reduced odds ratio (OR) of chronic diabetes complications, specifically CVD, micro-macroalbuminuria, and retinopathy (OR, 0.42; 95% CI, 0.23-0.77), independent of age, sex, physical activity, educational levels, diabetes duration, glycated hemoglobin, total insulin dose, hypertension, smoking, total cholesterol, albumin excretion rate, estimated glomerular filtration rate, serum vascular cell adhesion molecule-1, and tumor necrosis factor-α. Analyses performed separately for each complication demonstrated a significant independent association with albuminuria (OR, 0.36; 95% CI, (0.18-0.75) and CVD (OR, 0.34; 95% CI, 0.16-0.70).

CONCLUSIONS

In DM1 subjects, microRNA-191-5p is inversely associated with vascular chronic complications of diabetes.

Investigating miRNA subfamilies: Can they assist in the early diagnosis of acute myocardial infarction?

This report focuses on small non-coding RNA molecules (miRNAs), which have emerged as potential biomarkers with variable diagnostic values and false-positives in different conditions that limit their clinical preference. Current investigations focus on small non-coding RNA molecules (miRNAs), which have emerged as potential biomarkers with variable diagnostic values and false-positives in different conditions that limit their clinical preference. We thoroughly scrutinize the leading pathology of myocardial infarction and contemporary alterations in miRNAs for their specificity, stability and significant prognostic value at the early stage of acute myocardial infarction (AMI). Based on secondary data analysis, we explore common biomarkers and further investigate included miRNA biomarkers for their specificity, stability and area under the curve (AUC) values. We conclude that a group of novel biomarkers, including miRNA-1, miRNA-208a/b and miRNA-499, could help predict the emergence of AMI at an early stage.

Positive effect of miR-2392 on fibroblast to cardiomyocyte-like cell fate transition: an in silico and in vitro study

INTRODUCTION

Somatic cell fate transition is now gained great importance in tissue regeneration. Currently, research is focused on heart tissue regeneration by reprogramming diverse cells into cardiomyocyte-like cells. Here, we examined the possible effect of miRNAs on the transdifferentiation of fibroblasts into cardiomyocyte-like cells.

METHODS

First heart-specific miRNAs were identified by comparing the gene expression profiles of heart tissue to other body tissues using bioinformatic techniques. After identifying heart-specific miRNAs, their cellular and molecular functions were studied using the miRWalk and miRBase databases. Then the candidate miRNA was cloned into a lentiviral vector. Following, human dermal fibroblasts were cultured and treated with compounds forskolin, valproic acid, and CHIR99021. After 24 h, the lentivector harboring miRNA gene was transfected into the cells to initiate the transdifferentiation process. Finally, after a two-week treatment period, the efficiency of transdifferentiation was examined by inspecting the appearance of the cells and measuring the expression levels of cardiac genes and proteins using RT-qPCR and immunocytochemistry techniques.

RESULTS

Nine miRNAs were identified with higher expression in the heart. The miR-2392 was nominated as the candidate miRNA due to its function and specific expression in the heart. This miRNA has a direct connection with genes involved in cell growth and differentiation; e.g., MAPK and Wnt signaling pathways. According to in vitro results cardiac genes and proteins demonstrated an increase in expression in the fibroblasts that simultaneously received the three chemicals and miR-2392.

CONCLUSION

Considering the ability of miR-2392 to induce the expression of cardiac genes and proteins in fibroblast cells, it can induce fibroblasts to differentiate into cardiomyocyte-like cells. Therefore, miR-2392 could be further optimized for cardiomyocyte regeneration, tissue repair, and drug design studies.

Emerging Biomarkers of Acute Myocardial Infarction, An Overview of the Newest MicroRNAs

Globally, acute myocardial infarction (AMI) is the leading cause of death. Early and precise diagnosis is essential for medical care to enhance prognoses and reduce mortality. The diagnosis of AMI relies primarily on conventional circulating biomarkers. However, these markers have many drawbacks. Non-coding RNAs (ncRNAs) form a significant fraction of the transcriptome and have been shown to be essential for many biological processes, including the pathogenesis of the disease. ncRNAs can be utilized as biomarkers due to their important role in the disease's development. The current manuscript describes recent progress on the role of ncRNAs as new AMI biomarkers.

Emerging Biomarkers of Acute Myocardial Infarction, An Overview of the Newest MicroRNAs

Globally, acute myocardial infarction (AMI) is the leading cause of death. Early and precise diagnosis is essential for medical care to enhance prognoses and reduce mortality. The diagnosis of AMI relies primarily on conventional circulating biomarkers. However, these markers have many drawbacks. Non-coding RNAs (ncRNAs) form a significant fraction of the transcriptome and have been shown to be essential for many biological processes, including the pathogenesis of the disease. ncRNAs can be utilized as biomarkers due to their important role in the disease's development. The current manuscript describes recent progress on the role of ncRNAs as new AMI biomarkers.

Interplay between microRNAs, Serum Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9), and Lipid Parameters in Patients with Very High Lipoprotein(a) Treated with PCSK9 Inhibitors

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has an important function in the regulation of lipid metabolism. PCSK9 reduces hepatic low-density lipoprotein receptors, thereby increasing low-density lipoprotein cholesterol levels. However, its regulation remains to be elucidated, including post-transcriptional regulation by microRNAs (miRNAs). We aimed to explore the interplay between miRNAs, total serum PCSK9, and lipids during treatment with PCSK9 inhibitors. A total of 64 patients with stable coronary artery disease and very high lipoprotein(a) levels and 16 sex- and age-matched control subjects were enrolled. Patients received a PCSK9 inhibitor (evolocumab or alirocumab). Total serum PCSK9 levels were measured by immunoassay. RNA was isolated from plasma using magnetic beads, and expression of selected miRNAs was analyzed by quantitative PCR. Total serum PCSK9 levels were significantly higher in control subjects compared with patients. After 6 months of treatment with PCSK9 inhibitors, total serum PCSK9 levels increased significantly. The expression of miR-191-5p was significantly lower, and the expression of miR-224-5p and miR-483-5p was significantly higher in patients compared with control subjects. Using linear regression, the expression of miR-483-5p significantly predicted the serum PCSK9 level at baseline. After the 6-month period of therapy, the expression of miR-191-5p and miR-483-5p significantly increased. Our results support a role for miR-483-5p in regulating circulating PCSK9 in vivo. The difference in expression of miR-191-5p, miR-224-5p, and miR-337-3p between patients and control subjects suggests their possible role in the pathogenesis of coronary artery disease.

miR-96-5p regulates myocardial infarction-induced cardiac fibrosis via Smad7/Smad3 pathway

Fibrotic remodelling contributes to heart failure in myocardial infarction. MicroRNAs (miRNAs) play a crucial role in myocardial fibrosis. However, current antifibrotic therapeutic strategies using miRNAs are far from effective. In this study, we aim to investigate the effect of miR-96-5p on cardiac fibrosis. Our work reveals a significant upregulation of miR-96-5p level in the ventricular tissues of myocardial infarction mice, as well as in neonatal rat cardiac fibroblasts stimulated with TGF-β or Ang II as shown by qPCR assay. In myocardial infarction mice, miR-96-5p knockdown using antagomir alleviates the aggravated cardiac fibrosis and exacerbated myocardial function caused by myocardial infarction surgery as shown by the echocardiography and Masson's staining analysis. In contrast, immunofluorescence staining results reveal that miR-96-5p overexpression in neonatal rat cardiac fibroblasts contributes to an increase in the expressions of fibrosis-associated genes and promotes the proliferation and differentiation of cardiac fibroblasts. Conversely, miR-96-5p downregulation using inhibitor presents adverse consequences. Furthermore, Smad7 expression is downregulated in fibrotic cardiac tissues, and the Smad7 gene is identified as a direct target of miR-96-5p by dual luciferase assay. Indeed, Smad7 knockdown weakens the anti-fibrotic effect of the miR-96-5p inhibitor on cardiac fibroblasts. Moreover, Smad3 phosphorylation is elevated in fibrotic cardiac tissues, and interestingly, the Smad3 inhibitor suppresses the profibrotic effect of the miR-96-5p mimic. Taken together, our findings demonstrate that the Smad7/Smad3 signaling pathway mediates the profibrotic effect of miR-96-5p in cardiac fibrosis.

Adipose-Derived Stem Cell Exosomes and Related microRNAs in Atherosclerotic Cardiovascular Disease

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death from noncommunicable diseases worldwide. The pathological development of ASCVD begins with atherosclerosis, followed by the narrowing and occlusion of the vascular lumen and, subsequently, ischemic necrosis in coronary arteries. Preventing atherosclerosis development and delaying ischemia progression may be effective ways of pre-diagnosing and treating ASCVD. Studies have demonstrated that exosomes from adipose-derived stem cells play an increasingly important role in basic research on cardiovascular diseases in terms of the impact of macrophage polarization and the endothelial, anti-apoptosis, and angiogenesis effects. The related microRNAs play a significant role in ASCVD. This study was novel in reviewing the role of exosomes from adipose-derived stem cells and related microRNAs in ASCVD. Therapeutic potentials of adipose-derived stem cell exosomes in terms of their impact on macrophage polarization, endothelial effect, anti-apoptosis intervention, and angiogenesis.

Circulating miRNA Fingerprint and Endothelial Function in Myocardial Infarction: Comparison at Acute Event and One-Year Follow-Up

MicroRNAs (miRNA) are major regulators of intercellular communication and key players in the pathophysiology of cardiovascular disease. This study aimed to determine the miRNA fingerprint in a cohort of 53 patients with acute myocardial infarction (AMI) with non-ST-segment elevation (NSTEMI) relative to miRNA expression in healthy controls (n = 51). miRNA expression was initially profiled by miRNA array in the serum of patients undergoing cardiac catheterization during NSTEMI (n = 8) and 1 year past the event (follow-up, n = 8) and validated in the entire cohort. In total, 58 miRNAs were differentially expressed during AMI (p < 0.05), while 36 were modified at follow-up (Fisher’s exact test: p = 0.0138). Enrichment analyses revealed differential regulation of biological processes by miRNA at each specific time point (AMI vs. follow-up). During AMI, the miRNA profile was associated mainly with processes involved in vascular development. However, 1 year after AMI, changes in miRNA expression were partially related to the regulation of cardiac tissue morphogenesis. Linear correlation analysis of miRNA with serum levels of cytokines and chemokines revealed that let-7g-5p, let-7e-5p, and miR-26a-5p expression was inversely associated with serum levels of pro-inflammatory cytokines TNF-α, and the chemokines MCP-3 and MDC. Transient transfection of human endothelial cells (HUVEC) with let-7e-5p inhibitor or mimic demonstrated a key role for this miRNA in endothelial function regulation in terms of cell adhesion and angiogenesis capacity. HUVEC transfected with let-7e-5p mimic showed a 20% increase in adhesion capacity, whereas transfection with let-7e-5p inhibitor increased the number of tube-like structures. This study pinpoints circulating miRNA expression fingerprint in NSTEMI patients, specific to the acute event and changes at 1-year follow-up. Additionally, given its involvement in modulating endothelial cell function and vascularization, altered let-7e-5p expression may constitute a therapeutic biomarker and target for ischemic heart disease.

Circulating microRNAs as predictive biomarkers of coronary artery diseases in type 2 diabetes patients

BACKGROUND

Type 2 diabetes mellitus (T2DM) is an increasing metabolic disorder mostly resulting from unhealthy lifestyles. T2DM patients are prone to develop heart conditions such as coronary artery disease (CAD) which is a major cause of death in the world. Most clinical symptoms emerge at the advanced stages of CAD; therefore, establishing new biomarkers detectable in the early stages of the disease is crucial to enhance the efficiency of treatment. Recently, a significant body of evidence has shown alteration in miRNA levels associate with dysregulated gene expression occurring in T2DM and CAD, highlighting significance of circulating miRNAs in early detection of CAD arising from T2DM. Therefore, it seems crucial to establish a link between the miRNAs prognosing value and development of CAD in T2DM.

AIM

This study provides an overview on the alterations of the circulatory miRNAs in T2DM and various CADs and consider the potentials of miRNAs as biomarkers prognosing CADs in T2DM patients.

MATERIALS AND METHODS

Literature search was conducted for miRNAs involved in development of T2DM and CAD using the following key words: "miRNAs", "Biomarker", "Diabetes Mellitus Type 2 (T2DM)", "coronary artery diseases (CAD)". Articles written in the English language.

RESULT

There has been shown a rise in miR-375, miR-9, miR-30a-5p, miR-150, miR-9, miR-29a, miR-30d, miR-34a, miR-124a, miR-146a, miR-27a, and miR-320a in T2DM; whereas, miR-126, miR-21, miR-103, miR-28-3p, miR-15a, miR-145, miR-375, miR-223 have been shown to decrease. In addition to T2DM, some miRNAs such as mirR-1, miR-122, miR-132, and miR-133 play a part in development of subclinical aortic atherosclerosis associated with metabolic syndrome. Some miRNAs increase in both T2DM and CAD such as miR-1, miR-132, miR-133, and miR-373-3-p. More interestingly, some of these miRNAs such as miR-92a elevate years before emerging CAD in T2DM.

CONCLUSION

dysregulation of miRNAs plays outstanding roles in development of T2DM and CAD. Also, elevation of some miRNAs such as miR-92a in T2DM patients can efficiently prognose development of CAD in these patients, so these miRNAs can be used as biomarkers in this regard.

Circulating microRNA-208 family as early diagnostic biomarkers for acute myocardial infarction: A meta-analysis

OBJECTIVE

Many recent studies have demonstrated that serum miRNA-208 (miR-208) could be a powerful biomarker in the early diagnosis of acute myocardial infarction (AMI). However, the result of previous studies was not accurate due to the small sample sizes and controversial issues. Therefore, this study was performed to investigate the relationship between the expression levels of miR-208 and AMI.

MATERIALS AND METHODS

According to the inclusion and exclusion criteria, a preliminary literature search was performed. The study was based on articles published in PubMed, Embase, Cochrane databases before September 30, 2019. Two staff members extracted data from the included articles for meta-analysis. These data were analyzed for sensitivity, specificity, diagnostic odds ratio, and summary receiver operator curve (SROC) analyses.

RESULTS

This study included 13 pieces of literature, which contains 1703 patients with AMI and 1589 controls. The main results of our meta-analysis were as follows: The pool sensitivity and specificity of miR-208 for diagnosing AMI was 83% and 97%. The area under the SROC curve (AUC) was 93%. Mir-208 had a highly effective diagnostic capacity to distinguish AMI from chest pain patients with an AUC of 93%.

CONCLUSIONS

The results showed that circulating miR-208 was a reliable biomarker both for diagnosting ST-elevation myocardial infarction (STEMI) and non-ST elevation myocardial infarction (NSTEMI). MiR-208 was sufficient to distinguish AMI patients with chest pain from healthy controls.

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.

Clinical value of miR-191-5p in predicting the neurological outcome after out-of-hospital cardiac arrest

BACKGROUND

The diagnostic and prognostic value of microRNAs (miRNA) in human disease has been confirmed in a number of clinical studies.

AIMS

The purpose of this study was to investigate the predictive value of miR-191-5p in the neurological outcome of patients recovering from out-of-hospital cardiac arrest (OHCA).

METHODS

A total of 260 patients undergoing the target temperature management trial were analyzed. The expression level of serum miR-191-5p was detected by qRT-PCR at 48 h after return of spontaneous circulation (ROSC). ROC curve was established to evaluate the ability of miR-191-5p as a biomarker for predicting adverse neurological outcomes after OHCA. Kaplan-Meier curve and Cox regression analysis were used for survival analysis.

RESULTS

One hundred eighteen patients (45%) had poor neurological outcomes at 6 months. The expression level of serum miR-191-5p in patients with poor neurological outcomes was significantly lower than that in patients with good neurological prognosis (P < 0.001) and was not associated with TTM trial. The AUC, sensitivity, and specificity of the ROC curve were 0.899, 84.7%, and 82.4%, respectively, suggesting that the level of miR-191-5p had the ability to predict neurological outcome. By the end of the experiment, 88 patients (34%) were dead. Results of survival analysis showed that lower miR-191-5p expression level was significantly associated with lower survival rate (HR: 0.344, 95% CI = 0.208-0.567, P < 0.001).

CONCLUSIONS

The level of miR-191-5p was down-regulated in patients with poor neurological outcomes, and it could be used as a promising novel biomarker for prediction of neurological outcome and survival after OHCA.

Exploring diagnostic and prognostic predictive values of microRNAs for acute myocardial infarction: A PRISMA-compliant systematic review and meta-analysis

OBJECTIVE

Previous investigations yielded inconsistent results for diagnostic and prognostic predictive values of MicroRNAs (miRNAs) for acute myocardial infarction (AMI).

METHODS AND RESULTS

We systematically searched on PubMed and Web of Science for articles explored association of miRNAs and AMI published from January 1989 to March 2019. For diagnostic studies, a summary of sensitivity, specificity, positive likelihood ratios (PLR), negative likelihood ratios (NLR), and diagnostic odds ratio (DOR), which indicated the accuracy of microRNAs in the differentiation of AMI and no AMI, were calculated from the true positive (TP), true negative (TN), false positive (FP), and false negative (FN) of each study. In addition, the summary receive-operating characteristics (SROC) curve was constructed to summarize the TP and FP rates. For follow-up study, we computed hazard ratios (HRs) and 95% confidence intervals (CIs) for individual clinical outcomes. The meta-analysis showed a sensitivity [0.72 (95% CI: 0.61--0.81)] and specificity [0.88 (95% CI: 0.79--0.94)] of miR-1 for AMI. In addition, miR-133 showed a sensitivity [0.73 (95% CI: 0.55--0.85)] and specificity [0.88 (95% CI: 0.74--0.95)] for AMI. Moreover, the present study showed a sensitivity [0.83 (95% CI: 0.74--0.89)] and specificity [0.96 (95% CI: 0.82--0.99)] of miR-208 for AMI. A significant association was found between miR-208 and mortality after AMI (HR 1.09, 95% CI 1.01--1.18). It also indicated a sensitivity [0.84 (95% CI: 0.70--0.92)] and specificity [0.97 (95% CI: 0.87--0.99)] of miR-499 for AMI.

CONCLUSIONS

Circulating miR-1, miR-133, miR-208, and miR-499 showed diagnostic values in AMI.

MiR-208b Regulates Rabbit Preadipocyte Proliferation and Differentiation

microRNAs (miRNAs) play an important role in gene regulation in animals by pairing with target gene mRNA. Many miRNAs are differentially expressed in the adipose tissue, often with conserved expression. In our study, we found that miR-208b expression was observed differently in the preadipocyte differentiation model. When miR-208b was overexpressed in the preadipocyte differentiation model, the overexpressed group displayed higher expression of PPARγ and FABP4—the markers of preadipocyte differentiation. Oil Red O staining revealed that the count of lipid droplets was increased in the overexpressed group. When the expression of miR-208b was inhibited, the above indicators showed an opposite trend. Moreover, results from both 5-ethynyl-2′-deoxyuridine (EDU) and cell counting kit (CCK) analysis showed that miR-208b promoted the proliferation of preadipocyte. Expression of gene CSNK2A2, a direct miR-208b target, was downregulated in the overexpressed group, providing a possible link to multiple signal pathways. Overall, our data indicate that miR-208b play a positive regulatory effect on the proliferation and differentiation of rabbit preadipocyte.

Myocardial Infarction-Associated Extracellular Vesicle-Delivered miR-208b Affects the Growth of Human Umbilical Vein Endothelial Cells via Regulating CDKN1A

This study was aimed at investigating the effects of myocardial infarction- (MI-) associated extracellular vesicle- (EV-) delivered miR-208b on human umbilical vein endothelial cells (HUVECs). EVs were isolated and subsequently stained with PHK67. A dual-luciferase reporter gene assay was used to determine the target of miR-208b. Afterwards, HUVECs were transfected with either MI-associated EVs or miR-208b mimics, and cell viability, migration, and apoptosis were subsequently measured. Real-time quantitative polymerase chain reaction (RT-qPCR) was applied to determine the expressions of the tested genes. NanoSight, transmission electron microscopy, and western blotting showed that EVs were successfully isolated. Among the potential microRNA biomarkers for MI, miR-208b was chosen for subsequent experiments. We found that MI-associated EVs could be taken up by HUVECs and confirmed that CDKN1A was a direct target of miR-208b. Additionally, miR-208b mimics and MI-associated EVs significantly inhibited the viability and migration of HUVECs (P < 0.05) and promoted cell apoptosis, as well as reduced S phase and increased G2/M phase cell distribution. RT-qPCR revealed that both miR-208b mimics and MI-associated EVs upregulated the expressions of CDKN1A, FAK, Raf-1, MAPK1, and Bax but downregulated the expression of Bcl2 and reduced the Bcl2/Bax ratio. Our study concludes that MI-associated EVs delivered miR-208b to HUVECs, and EV-delivered miR-208b could affect the growth of HUVECs by regulating the miR-208b/CDKN1A pathway; thus, miR-208b can be therefore served as important therapeutic targets for MI treatment.

Differential miRNAs in acute spontaneous coronary artery dissection: Pathophysiological insights from a potential biomarker

BACKGROUND

Spontaneous Coronary Artery Dissection (SCAD) is an important cause of acute coronary syndromes, particularly in young to middle-aged women. Differentiating acute SCAD from coronary atherothrombosis remains a major clinical challenge.

METHODS

A case-control study was used to explore the usefulness of circulating miRNAs to discriminate both clinical entities. The profile of miRNAs was evaluated using an unbiased human RT-PCR platform and confirmed using individual primers. miRNAs were evaluated in plasma samples from acute SCAD and atherothrombotic acute myocardial infarction (AT-AMI) from two independent cohorts; discovery cohort (SCAD n = 15, AT-AMI n = 15), and validation cohort (SCAD n = 11, AT-AMI n = 41) with 9 healthy control subjects. Plasma levels of IL-8, TGFB1, TGBR1, Endothelin-1 and MMP2 were analysed by ELISA assays.

FINDINGS

From 15 differentially expressed miRNAs detected in cohort 1, we confirmed in cohort 2 the differential expression of 4 miRNAs: miR-let-7f-5p, miR-146a-5p, miR-151a-3p and miR-223-5p, whose expression was higher in SCAD compared to AT-AMI. The combined expression of these 4 miRNAs showed the best predictive value to distinguish between both entities (AUC: 0.879, 95% CI 0.72-1.0) compared to individual miRNAs. Functional profiling of target genes identified an association with blood vessel biology, TGF-beta pathway and cytoskeletal traction force. ELISA assays showed high plasma levels of IL-8, TGFB1, TGFBR1, Endothelin-1 and MMP2 in SCAD patients compared to AT-AMI.

INTERPRETATION

We present a novel signature of plasma miRNAs in patients with SCAD. miR-let-7f-5p, miR-146a-5p, miR-151a-3p and miR-223-5p discriminate SCAD from AT-AMI patients and also shed light on the pathological mechanisms underlying this condition.

FUNDING

Spanish Ministry of Economy and Competitiveness (MINECO): Plan Nacional de Salud SAF2017-82886-R, Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV). Fundación BBVA a equipos de Investigación Científica 2018 and from Caixa Banking Foundation under the project code HR17-00016 to F.S.M. Instituto de Salud Carlos III (AES 2019): PI19/00565 to F.R, PI19/00545 to P.M. CAM (S2017/BMD-3671-INFLAMUNE-CM) from Comunidad de Madrid to FSM and PM. The UK SCAD study was supported by BeatSCAD, the British Heart Foundation (BHF) PG/13/96/30608 the NIHR rare disease translational collaboration and the Leicester NIHR Biomedical Research Centre.

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

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

The antagonistic effects and mechanisms of microRNA-26a action in hypertensive vascular remodelling

BACKGROUND AND PURPOSE

Hypertensive vascular remodelling is responsible for end-organ damage and is the result of increased extracellular matrix accumulation and excessive vascular smooth muscle cell (VSMC) proliferation. MicroRNA-26a (miR-26a), a non-coding small RNA, is involved in several cardiovascular diseases. We aimed to validate the effect and mechanisms of miR-26a in hypertensive vascular remodelling.

EXPERIMENTAL APPROACH

Male spontaneously hypertensive rats (SHRs) were injected intravenously with recombinant adeno-associated virus-miR-26a. Samples of thoracic aorta were examined histologically with H&E staining. In vitro, angiotensin II (AngII)-induced VSMCs cultured from thoracic aortae of female Sprague-Dawley rats, were transfected with miR-26a mimic or inhibitor. Western blots, qRT-PCR and immunohistological methods were used, along with chromatin-immunoprecipitation and luciferase reporter assays. Specific siRNAs were used to silence Smad production in VSMCs KEY RESULTS: Levels of miR-26a were lower in the thoracic aorta and plasma of SHRs than in WKY rats. Overexpression of miR-26a inhibited extracellular matrix deposition by targeting connective tissue growth factor (CTGF) and decreased VSMC proliferation by regulating the enhancer of zeste homologue 2 (EZH2)/p21 pathway both in vitro and in vivo. AngII-mediated Smad3 activation suppressed miR-26a expression, which in turn promoted Smad3 activation via targeted regulation of Smad4, leading to further down-regulation of miR-26a.

CONCLUSION AND IMPLICATIONS

Our data show that AngII stimulated a Smads/miR-26a positive feedback loop, which further reduced expression of miR-26a, leading to collagen production and VSMC proliferation and consequently vascular remodelling. MiR-26a has an antagonistic effect on hypertensive vascular remodelling and can be a strategy for treating hypertensive vascular remodelling.

Value of Blood-Based microRNAs in the Diagnosis of Acute Myocardial Infarction: A Systematic Review and Meta-Analysis

Background: Recent studies have shown that blood-based miRNAs are dysregulated in patients with acute myocardial infarction (AMI) and are therefore a potential tool for the diagnosis of AMI. Therefore, this study summarized and evaluated studies focused on microRNAs as novel biomarkers for the diagnosis of AMI from the last ten years. Methods: MEDLINE, the Cochrane Central database, and EMBASE were searched between January 2010 and December 2019. Studies that assessed the diagnostic accuracy of circulating microRNAs in AMI were chosen. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve (AUC) were used to assess the test performance of miRNAs. Results: A total of 58 studies that included 8,206 participants assessed the diagnostic accuracy of circulating miRNAs in AMI. The main results of the meta-analyses are as follows: (1) Total miRNAs: the overall pooled sensitivity and specificity were 0.82 (95% CI: 0.79-0.85) and 0.87 (95% CI: 0.84-0.90), respectively. The AUC value was 0.91 (95% CI: 0.88-0.93) in the overall summary receiver operator characteristic (SROC) curve. (2) The panel of two miRNAs: sensitivity: 0.88 (95% CI: 0.77-0.94), specificity: 0.84 (95% CI: 0.72-0.91), AUC: 0.92 (95% CI: 0.90-0.94). (3) The panel of three miRNAs: sensitivity: 0.91 (95% CI: 0.85-0.94), specificity: 0.87 (95% CI: 0.77-0.92), AUC: 0.92 (95% CI: 0.89-0.94). (4) Results by types of miRNAs: miRNA-1: sensitivity: 0.78 (95% CI: 0.71-0.84), specificity: 0.86 (95% CI: 0.77-0.91), AUC: 0.88 (95% CI: 0.85-0.90); miRNA-133a: sensitivity: 0.85 (95% CI: 0.69-0.94), specificity: 0.92 (95% CI: 0.61-0.99), AUC: 0.93 (95% CI: 0.91-0.95); miRNA-208b: sensitivity: 0.80 (95% CI: 0.69-0.88), specificity: 0.96 (95% CI: 0.77-0.99), AUC: 0.91 (95% CI: 0.88-0.93); miRNA-499: sensitivity: 0.85 (95% CI: 0.77-0.91), specificity: 0.95 (95% CI: 0.89-0.98), AUC: 0.96 (95% CI: 0.94-0.97). Conclusion: miRNAs may be used as potential biomarkers for the detection of AMI. For single, stand-alone miRNAs, miRNA-499 may have better diagnostic accuracy compared to other miRNAs. We propose that a panel of multiple miRNAs with high sensitivity and specificity should be tested.

MicroRNA-331 and microRNA-151-3p as biomarkers in patients with ST-segment elevation myocardial infarction

We sought to analyse plasma levels of peripheral blood microRNAs (miRs) as biomarkers of ST-segment-elevation myocardial infarction (STEMI) due to type-1 myocardial infarction as a model situation of vulnerable plaque (VP) rupture. Samples of 20 patients with STEMI were compared both with a group of patients without angina pectoris in whom coronary angiogram did not reveal coronary atherosclerotic disease (no coronary atherosclerosis-NCA) and a group of patients with stable angina pectoris and at least one significant coronary artery stenosis (stable coronary artery disease-SCAD). This study design allowed us to identify miRs deregulated in the setting of acute coronary artery occlusion due to VP rupture. Based on an initial large scale miR assay screening, we selected a total of 12 miRs (three study miRs and nine controls) that were tested in the study. Two of the study miRs (miR-331 and miR-151-3p) significantly distinguished STEMI patients from the control groups, while ROC analysis confirmed their suitability as biomarkers. Importantly, this was observed in patients presenting early with STEMI, even before the markers of myocardial necrosis (cardiac troponin I, miR-208 and miR-499) were elevated, which suggests that the origin of miR-331 and miR-151-3p might be in the VP. In conclusion, the study provides two novel biomarkers observed in STEMI, which may be associated with plaque rupture.

Circulating miRNAs Related to Long-term Adverse Cardiovascular Events in STEMI Patients: A Nested Case-Control Study

BACKGROUND

Long-term morbidity and mortality of patients with ST-segment-elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (PCI) remain substantial. Circulating microRNAs (miRNAs) play an important role in cardiovascular disease development. We aimed to identify circulating miRNAs associated with adverse cardiovascular events after acute myocardial infarction (AMI).

METHODS

We performed a prospective, nested, case-control study of 932 patients with STEMI who underwent primary PCI. A 3-phase approach was conducted to screen candidate circulating miRNAs in 70 patients who subsequently experienced cardiac death, hospitalization for heart failure, or recurrent AMI (major adverse cardiovascular events [MACE] group) and in 140 patients matched for age, sex, time from symptom onset to blood collection and dual-antiplatelet therapy who did not report adverse cardiovascular events during 2-year follow-up (non-MACE group).

RESULTS

We found that miR-26a-5p, miR-21-5p, and miR-191-5p levels were lower in the MACE group than in the non-MACE group (all P < 0.001). Multivariate conditional logistic regression analysis revealed that miR-26a-5p, miR-21-5p, and miR-191-5p levels were significantly inversely associated with incident primary composite outcomes (all adjusted P < 0.01). Importantly, the combination of these 3 miRNAs plus B-type natriuretic peptide clearly improved the risk scores recommended in the current guidelines, as determined with the use of C-statistics, net reclassification, and integrated discrimination.

CONCLUSIONS

Our study provides proof-of-concept in humans that circulating miRNAs are associated with increased rates of distinct cardiovascular events, suggesting that they can serve as effective prognostic biomarkers and therapeutic targets for patients with AMI.

Diagnostic and prognostic impact of circulating microRNA-208b and microRNA-499 in patients with acute coronary syndrome

Aim: This study aimed to investigate the correlation between the expression of circulating miR-208b and miR-499 and acute coronary syndrome (ACS) patients. Materials & methods: A total of 160 consecutive patients with ACS and 48 healthy control subjects were enrolled for primary analysis. The ACS patients (n = 160) were followed up for 6 months for further analysis regarding major adverse cardiac events. Results: Area under the curve values of miR-208b and miR-499 for predicting ACS were 0.910 and 0.851 (p < 0.001, respectively). Cox proportional hazards regression analysis revealed that miR-208b but not miR-499 was an independent predictor of major adverse cardiac events. Conclusion: Circulating miR-208b and miR-499 could be considered as diagnostic or prognostic biomarkers for patients with ACS.

miR-26a attenuates cardiac apoptosis and fibrosis by targeting ataxia-telangiectasia mutated in myocardial infarction

Apoptosis and fibrosis play a vital role in myocardial infarction (MI) induced tissue injury. Although microRNAs have been the focus of many studies on cardiac apoptosis and fibrosis in MI, the detailed effects of miR-26a is needed to further understood. The present study demonstrated that miR-26a was downregulated in ST-elevation MI (STEMI) patients and oxygen-glucose deprivation (OGD)-treated H9c2 cells. Downregulation of miR-26a was closely correlated with the increased expression of creatine kinase, creatine kinase-MB and troponin I in STEMI patients. Further analysis identified that ataxia-telangiectasia mutated (ATM) was a target gene for miR-26a based on a bioinformatics analysis. miR-26a overexpression effectively reduced ATM expression, apoptosis, and apoptosis-related proteins in OGD-treated H9c2 cells. In a mouse model of MI, the expression of miR-26a was significantly decreased in the infarct zone of the heart, whereas apoptosis and ATM expression were increased. miR-26a overexpression effectively reduced ATM expression and cardiac apoptosis at Day 1 after MI. Furthermore, we demonstrated that overexpression of miR-26a improved cardiac function and reduced cardiac fibrosis by the reduced expression of collagen type I and connective tissue growth factor (CTGF) in mice at Day 14 after MI. Overexpression of miR-26a or ATM knockdown decreased collagen I and CTGF expression in cultured OGD-treated cardiomyocytes. Taken together, these data demonstrate a prominent role for miR-26a in linking ATM expression to ischemia-induced apoptosis and fibrosis, key features of MI progression. miR-26a reduced MI development by affecting ATM expression and could be targeted in the treatment of MI.

Anti-CD3 Antibody Treatment Reduces Scar Formation in a Rat Model of Myocardial Infarction

Introduction: Antibody treatment with anti-thymocyte globulin (ATG) has been shown to be cardioprotective. We aimed to evaluate which single anti-T-cell epitope antibody alters chemokine expression at a level similar to ATG and identified CD3, which is a T-cell co-receptor mediating T-cell activation. Based on these results, the effects of anti-CD3 antibody treatment on angiogenesis and cardioprotection were tested in vitro and in vivo. Methods: Concentrations of IL-8 and MCP-1 in supernatants of human peripheral blood mononuclear cell (PBMC) cultures following distinct antibody treatments were evaluated by Enzyme-linked Immunosorbent Assay (ELISA). In vivo, anti-CD3 antibodies or vehicle were injected intravenously in rats subjected to acute myocardial infarction (AMI). Chemotaxis and angiogenesis were evaluated using tube and migration assays. Intracellular pathways were assessed using Western blot. Extracellular vesicles (EVs) were quantitatively evaluated using fluorescence-activated cell scanning, exoELISA, and nanoparticle tracking analysis. Also, microRNA profiles were determined by next-generation sequencing. Results: Only PBMC stimulation with anti-CD3 antibody led to IL-8 and MCP-1 changes in secretion, similar to ATG. In a rat model of AMI, systemic treatment with an anti-CD3 antibody markedly reduced infarct scar size (27.8% (Inter-quartile range; IQR 16.2–34.9) vs. 12.6% (IQR 8.3–27.2); p < 0.01). The secretomes of anti-CD3 treated PBMC neither induced cardioprotective pathways in cardiomyocytes nor pro-angiogenic mechanisms in human umbilical vein endothelial cell (HUVECs) in vitro. While EVs quantities remained unchanged, PBMC incubation with an anti-CD3 antibody led to alterations in EVs miRNA expression. Conclusion: Treatment with an anti-CD3 antibody led to decreased scar size in a rat model of AMI. Whereas cardioprotective and pro-angiogenetic pathways were unaltered by anti-CD3 treatment, qualitative changes in the EVs miRNA expression could be observed, which might be causal for the observed cardioprotective phenotype. We provide evidence that EVs are a potential cardioprotective treatment target. Our findings will also provide the basis for a more detailed analysis of putatively relevant miRNA candidates.

The role of endothelial miRNAs in myocardial biology and disease

The myocardium is a highly structured pluricellular tissue which is governed by an intricate network of intercellular communication. Endothelial cells are the most abundant cell type in the myocardium and exert crucial roles in both healthy myocardium and during myocardial disease. In the last decade, microRNAs have emerged as new actors in the regulation of cellular function in almost every cell type. Here, we review recent evidence on the regulatory function of different microRNAs expressed in endothelial cells, also called endothelial microRNAs, in healthy and diseased myocardium. Endothelial microRNA emerged as modulators of angiogenesis in the myocardium, they are implicated in the paracrine role of endothelial cells in regulating cardiac contractility and homeostasis, and interfere in the crosstalk between endothelial cells and cardiomyocytes.

Transcription Factors Targeted by miRNAs Regulating Smooth Muscle Cell Growth and Intimal Thickening after Vascular Injury

Neointima formation after percutaneous coronary intervention (PCI) is a manifestation of “phenotype switching” by vascular smooth muscle cells (SMC), a process that involves de-differentiation from a contractile quiescent phenotype to one that is richly synthetic. In response to injury, SMCs migrate, proliferate, down-regulate SMC-specific differentiation genes, and later, can revert to the contractile phenotype. The vascular response to injury is regulated by microRNAs (or miRNAs), small non-coding RNAs that control gene expression. Interactions between miRNAs and transcription factors impact gene regulatory networks. This article briefly reviews the roles of a range of miRNAs in molecular and cellular processes that control intimal thickening, focusing mainly on transcription factors, some of which are encoded by immediate-early genes. Examples include Egr-1, junB, KLF4, KLF5, Elk-1, Ets-1, HMGB1, Smad1, Smad3, FoxO4, SRF, Rb, Sp1 and c-Myb. Such mechanistic information could inform the development of strategies that block SMC growth, neointima formation, and potentially overcome limitations of lasting efficacy following PCI.

MicroRNAs in acute myocardial infarction: Evident value as novel biomarkers?

Traditional circulating biomarkers play a fundamental role in the diagnosis and prognosis of acute myocardial infarction (AMI). However, they have several limitations. microRNAs (miRs), a class of RNA molecules that do not encode proteins, function directly at the RNA level by inhibiting the translation of messenger RNAs. Due to their significant roles in disease development, they can be used as biomarkers. Accumulating evidence has revealed an attractive role of miRs as biomarkers of AMI and its associated symptoms, including vulnerable atherosclerotic plaques, and their role in disease diagnosis, platelet activation monitoring, and prognostic outcome prediction. This manuscript will highlight the recent updates regarding the involvement of miRs as biomarkers in AMI and emphasize their value in vulnerable atherosclerotic plaque prediction and monitoring of platelet activation.

MiR-128/SOX7 alleviates myocardial ischemia injury by regulating IL-33/sST2 in acute myocardial infarction

Acute myocardial infarction (AMI) induced by ischemia hypoxia severely threatens human life. Cell apoptosis of neurocytes was identified to mediate the pathogenesis, while the potential mechanism was still unclear. Sprague Dawley (SD) rats were used to establish the AMI rat model. Real-time polymerase chain reaction (PCR) and Western blot were performed to detect gene expression in mRNA and protein levels, respectively. A TUNEL assay was carried out to determine cell apoptosis. The relationship between SRY-related HMG-box (SOX7) and miR-128 was verified using luciferase reporter assay. The expression of SOX7 was decreased, while miR-128 was increased in AMI rats and ischemia hypoxia (IH) induced H9c2 cells. Hypoxia induction significantly promoted the expression of interleukin (IL)-33 and soluble ST2 (sST2), and also promoted cell apoptosis. MiR-128 targets SOX7 to regulate its expression. Down-regulated miR-128 reversed the effects of IH on expression of SOX7, sST2 and cell apoptosis, while down-regulated sST2 abolished the effects of miR-128 inhibitor. In addition, overexpressed IL-33 abolished the effects of miR-128 inhibitor that induced by IH on the expression of SOX7 and cell apoptosis. In vivo experiments validated the expression of miR-128 on cell apoptosis. The present study indicated that miR-128 modulated cell apoptosis by targeting SOX7, which was mediated by IL-33/sST2 signaling pathway.

NGS-identified circulating miR-375 as a potential regulating component of myocardial infarction associated network

Acute myocardial infarction (MI), the most severe type of coronary heart disease, is a leading cause of disability and mortality worldwide. In order to investigate the involvement of miRNAs in the pathologic processes related to MI, we performed the analysis of circulating miRNAs - stable short noncoding RNA molecules - in the peripheral blood plasma of MI patients compared to healthy controls (all persons were men and lived in European Russia) using next generation sequencing. We observed 20 miRNAs, which levels in plasma more than two-fold differed in MI patients (p < 0.05). Among them miR-208b and miR-375 passed threshold for multiple corrections (FC = 49.2, FDR-adjusted p-value = 0.0078 and FC = -6.4, FDR-adjusted p-value = 0.00076, respectively); these data were then validated using RT-qPCR (FC = 5.3, p-value = 0.028 and FC = -2.1, p-value = 0.0039, respectively). While for miR-208b we reidentified earlier observations, miR-375 was found to be associated with MI for the first time. To investigate the reasons for which miR-375 holds a special place among circulating miRNAs in MI, enrichment and network analyses of miR-375 target genes and their interactions were carried out. PIK3CA and TP53 genes, regulated by miR-375, were identified as the key players of MI disease module.

Non-coding RNAs as biomarkers for acute myocardial infarction

Acute myocardial infarction (AMI) is a main threat to human lives worldwide. Early and accurate diagnoses warrant immediate medical care, which would reduce mortality and improve prognoses. Circulating non-coding RNAs have been demonstrated to serve as competent biomarkers for various diseases. Following the identification of cardiac-specific microRNA miR-208a in circulation, more non-coding RNAs (miR-1, miR-499 and miR-133) have been identified as biomarkers not only for the diagnosis of AMI but also for prognosis post infarction. Here, we summarized recent findings on non-coding RNAs as biomarkers for early diagnosis of ST-segment elevation myocardial infarction and for disease monitoring of myocardial infarction. In addition, the prognostic potential of non-coding RNAs in patients treated with percutaneous coronary intervention was also described. We also include studies based on biobanks, and build a miRNA release spectrum after AMI, which provides quantitative and time-lapse monitoring of AMI progress. With this spectrum, we are able to customize personal medical care, which prevents further damage. By constructing a network of circulating non-coding RNAs with high specificity and sensitivity, detailed diagnostic information was provided for personalized medicine. Unveiling the roles and kinetics of circulating non-coding RNAs may lead to a revolution in clinical diagnosis.

At the heart of programming: the role of micro-RNAs

Epidemiological and experimental observations tend to prove that environment, lifestyle or nutritional challenges influence heart functions together with genetic factors. Furthermore, when occurring during sensitive windows of heart development, these environmental challenges can induce an 'altered programming' of heart development and shape the future heart disease risk. In the etiology of heart diseases driven by environmental challenges, epigenetics has been highlighted as an underlying mechanism, constituting a bridge between environment and heart health. In particular, micro-RNAs which are involved in each step of heart development and functions seem to play a crucial role in the unfavorable programming of heart diseases. This review describes the latest advances in micro-RNA research in heart diseases driven by early exposure to challenges and discusses the use of micro-RNAs as potential targets in the reversal of the pathophysiology.

A Preliminary Study of microRNA-208b after Acute Myocardial Infarction: Impact on 6-Month Survival

Introduction

miRNAs contribute to a variety of essential biological processes including development, proliferation, differentiation, and apoptosis. Circulating microRNAs are very stable and have shown potential as biomarkers of cardiovascular disease. microRNA-208b expression was increased in the blood of patients with acute myocardial infarction (AMI) and has been proposed as a biomarker for early diagnosis. In this pilot study, we investigate the potential of circulating miR-208b as a prognostic biomarker of 6-month survival in AMI patients.

Methods

Plasma samples from 21 patients and 8 age- and gender-matched healthy adults were collected, and circulating levels of miR-208b were detected using quantitative real-time PCR.

Results

miR-208b levels were higher in healthy control subjects (9.6-fold; P ≤ 0.05). Within the AMI patients, the levels of miR-208b were significantly lower in the survivor versus nonsurvivor group (fold change = 6.51 and 14.1, resp.; P ≤ 0.05). The Kaplan-Meier curve revealed that the 6-month survival time was significantly higher among AMI patients with a relative expression of miR-208b lower than 12.38. The hazard ratio (HR) for the relative expression of miR-208b (<12.38 was the reference) was 5.08 (95% CI: 1.13–22.82; P = 0.03).

Conclusion

Our results showed that elevated miR-208b expression was associated with reduced long-term survival in AMI patients. These pilot data indicate the need for a large follow-up study to confirm whether miR-208b can be used as a predictor of 6-month survival time after AMI.

Expression of miR-208b and miR-499 in Greek Patients with Acute Myocardial Infarction

BACKGROUND/AIM

Certain microRNAs (miRs) present in human plasma are candidate biomarkers for cardiovascular diseases, including acute myocardial infarction (AMI). We examined the expression of two cardiac-specific miRs (miR-208b and miR-499) in a Greek pathological population.

MATERIALS AND METHODS

Plasma samples from AMI patients and healthy subjects (controls) were analyzed using TaqMan® MicroRNA assays.

RESULTS

The concentration of both miRs was significantly elevated in AMI patients compared to healthy controls. Moreover, receiver-operating characteristic (ROC) curve analysis showed that miR-208b and miR-499 displayed similar properties with the established AMI biomarker cardiac troponin T (cTnT).

CONCLUSION

We showed, for the first time, that these miRs could be used as AMI biomarkers in our population as well. Our data are in agreement with those of studies based on different population groups and further strengthen the observation that plasma levels of circulating miR-208b and miR-499 could serve as potential AMI biomarkers.

The Potential Role of Platelet-Related microRNAs in the Development of Cardiovascular Events in High-Risk Populations, Including Diabetic Patients: A Review

Platelet activation plays a pivotal role in the development and progression of atherosclerosis, which often leads to potentially fatal ischemic events at later stages of the disease. Platelets and platelet microvesicles (PMVs) contain large amounts of microRNA (miRNA), which contributes largely to the pool of circulating miRNAs. Hence, they represent a promising option for the development of innovative diagnostic biomarkers, that can be specific for the underlying etiology. Circulating miRNAs can be responsible for intracellular communication and may have a biological effect on target cells. As miRNAs associated to both cardiovascular diseases (CVD) and diabetes mellitus can be measured by means of a wide array of techniques, they can be exploited as an innovative class of smart disease biomarkers. In this manuscript, we provide an outline of miRNAs associated with platelet function and reactivity (miR-223, miR-126, miR-197, miR-191, miR-21, miR-150, miR-155, miR-140, miR-96, miR-98) that should be evaluated as novel biomarkers to improve diagnostics and treatment of CVD.

Down-regulation of miR-26a-5p in hepatocellular carcinoma: A qRT-PCR and bioinformatics study

BACKGROUND

To practically verify the clinical value of miR-26a-5p and thoroughly explore its target genes as well as its potential functions in hepatocellular carcinoma (HCC).

METHODS

HCC and adjacent non-cancerous hepatic tissues of 95 HCC patients were collected for analysis using reverse transcription quantitative real-time PCR (qRT-PCR). For the bioinformatics analysis, we identified potential target genes for miR-26a-5p from differentially expressed genes (DEGs) in Gene Expression Omnibus (GEO) data sets and miRWalk predicted database. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and protein-protein interaction (PPI) analyses were applied to analyze the prospective mechanisms of the predicted target genes.

RESULTS

MiR-26a-5p showed a significantly lower expression level in HCC tissues (1.56±1.07) than adjacent benign liver tissues (2.28±1.06, P<0.001). The area under the curve (AUC) of the receiver operating characteristic (ROC) was 0.665 (95% CI: 0.588-0.743, P<0.001). Significant correlations between miR-26a-5p expression and clinicopathological features such as gender (r=0.275, P<0.01), clinical TNM stage (r=-0.306, P<0.01), and metastasis (r=-0.321, P<0.01) were observed. To examine potential target genes, we obtained 175 genes for further function analysis, by attaining the intersection of 2062 up-regulated DEGs and 1390 online-predicted target genes. The GO and KEGG pathway annotation indicated focal adhesion, regulation of actin cytoskeleton and the PI3K-Akt signaling pathway as significant prospective mechanisms. The PPI network indicated that NRAS was the most essential hub gene in the whole network.

CONCLUSION

Down-regulated miR-26a-5p was closely correlated with the status of metastasis and the progression of HCC. MiR-26a-5p might play protective roles by targeting diverse genes and pathways.

Electroacupuncture Alleviates Brain Damage Through Targeting of Neuronal Calcium Sensor 1 by miR-191a-5p After Ischemic Stroke

Electroacupuncture (EA) administration before or after cerebral ischemia has been shown to afford protection against ischemic injury. However, the underlying mechanism of EA-mediated protection is still unclear. Functional microRNAs (miRNAs) are believed to play important roles in neuroprotection and synaptic plasticity during and after ischemia. In a previous study, we identified 20 miRNAs that are expressed in the penumbra and are significantly changed after EA treatment. Here, we used bioinformatic analysis to predict the biological functions and gene networks of these miRNAs. Consistent with our predictions, downregulation of miR-191a-5p in primary neurons and in cortexes of rats increased cell viability, decreased apoptosis, reduced infarct volumes, and improved neurological scores; whereas upregulation of miR-191a-5p exacerbated neuronal injury and partly reversed the neuroprotective effect of EA treatment after ischemia/reperfusion injury. In silico analysis predicted that miR-191a-5p targets neuronal calcium sensor 1 (NCS-1), brain-derived neurotrophic factor, and growth-associated protein 43 (GAP43), and using luciferase reporter assays, we confirmed that the NCS-1 3'UTR (untranslated region) is targeted by miR-191a-5p. Furthermore, lentivirus-mediated overexpression of NCS-1 in primary neurons and in the cortexes of rats induced neuroprotection, while lentivirus-mediated knockdown had the opposite effect. Taken together, these data suggest that miRNAs participate in the response to EA treatment after cerebral ischemia and further imply that NCS-1 may constitute a miR-191a-5p target gene and a potential therapeutic target for neuroprotection.

A comprehensive insight into the clinicopathologic significance of miR-144-3p in hepatocellular carcinoma

BACKGROUND

Studies which focused on the character of miR-144-3p in hepatocellular carcinoma (HCC) are limited. This study aimed to explore the expression, clinical significance and the potential targets of miR-144-3p in HCC.

METHODS

The Cancer Genome Atlas (TCGA) and a cohort of 95 cases of HCC were applied to investigate aberrant miR-144-3p expression in HCC. A meta-analysis was performed to accumulate data on miR-144-3p expression in HCC based on TCGA, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Gene Expression Omnibus (GEO). Additionally, the potential regulatory mechanisms of miR-144-3p in HCC were explored by bioinformatics.

RESULTS

MiR-144-3p expression was downregulated distinctly in HCC compared to para-HCC tissue both in TCGA data (8.9139±1.5986 vs 10.7721±0.9156, P<0.001) and in our qRT-PCR validation (1.3208±0.7594 vs 2.6200±0.9263, P<0.001). The meta-analysis based on TCGA, qRT-PCR and GEO data confirmed a consistent result (standard mean difference =-0.854, 95% CI: -1.224 to -0.484, P<0.001). The receiver operating characteristic curve of miR-144-3p gained a significant diagnostic value both in TCGA data (area under the curve [AUC] =0.852, 95% CI: 0.810 to 0.894, P<0.001) and in qRT-PCR validation (AUC =0.867, 95% CI: 0.817 to 0.916, P<0.001), especially in alpha-fetoprotein-negative HCC patients (AUC =0.900, 95% CI: 0.839 to 0.960, P<0.001). Furthermore, we identified 119 potential targets of miR-144-3p in HCC by bioinformatics. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that several significant biologic functions and pathways correlated with the pathogenesis of HCC, including the p53 signaling pathway.

CONCLUSION

MiR-144-3p may function as a cancer suppressor microRNA, which is essential for HCC progression through the regulation of various signaling pathways. Thus, interactions with miR-144-3p may provide a novel treatment strategy for HCC in the future.

Expression of miR-126 and its potential function in coronary artery disease

OBJECTIVE

This study aimed to explore the role of miR-126 in coronary artery disease (CAD) patients and the potential gene targets of miR-126 in atherosclerosis.

METHODOLOGY

A total of 60 CAD patients and 25 healthy control subjects were recruited in this study. Among the 60 CAD patients, 18 cases were diagnosed of stable angina pectoris (SAP), 20 were diagnosed of unstable angina pectoris (UAP) and 22 were diagnosed of acute myocardial infarction (AMI). Plasma miR-126 levels from both groups of participants were analyzed by real-time quantitative PCR. ELISA was used to measure plasma level of placenta growth factor (PLGF).

RESULTS

The results showed that the miR-126 expression was significantly down-regulated in the circulation of CAD patients compared with control subjects (P<0.01). Plasma PLGF level was significantly upregulated in patients with unstable angina pectoris and acute myocardial infarction (AMI) compared with controls (both P<0.01) the miR-126 expression in AMI was significantly associated with PLGF.

CONCLUSION

miR-126 may serve as a novel biomarker for CAD.

Identification of microRNAs as diagnostic biomarkers for acute myocardial infarction in Asian populations: A systematic review and meta-analysis

BACKGROUND

Acute myocardial infarction (AMI) is one of the leading causes of mortality and morbidity worldwide. Recently, several studies have revealed the diagnostic value of circulating microRNAs (miRNAs) for AMI detection. However, the diagnostic capacity of miRNAs for AMI is still controversial due to the inconsistent results among studies.

METHODS

A systematic literature search was conducted to retrieve relevant articles in PubMed and other databases up to February 2017. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were used to assess the overall test performance of miRNAs. Subgroup analysis was conducted to explore the potential sources of heterogeneity. We evaluated the publication bias by the Deeks' funnel plot asymmetry test and all statistical analyses were performed using Meta-disc 1.4 and Stata software.

RESULTS

A total of 26 articles comprising 1973 AMI patients and 1236 healthy controls were included in this meta-analysis. The overall pooled diagnostic data was as follows: the pooled sensitivity of 0.76 (95% confidence interval [CI]: 0.75-0.78), the pooled specificity of 0.82 (95% CI: 0.81-0.84), the pooled PLR of 4.68 (95% CI: 3.92-5.59), the pooled NLR of 0.28 (95% CI: 0.25-0.32), and the pooled DOR of 18.66 (95% CI: 14.11-24.68). The AUC value was 0.8661 in the overall summary receiver operator characteristic curve. Subgroup analysis indicated that miRNA-499 had better diagnostic accuracy over other miRNAs.

CONCLUSION

MiRNAs may serve as promising diagnostic biomarkers in the early diagnosis of AMI. Further studies were needed to evaluate the diagnostic value of miRNAs for AMI before clinical application.

Circulating MicroRNAs in Delayed Cerebral Infarction After Aneurysmal Subarachnoid Hemorrhage

Background

Delayed cerebral infarction (DCI) is a major cause of morbidities after aneurysmal subarachnoid hemorrhage (SAH) and typically starts at day 4 to 7 after initial hemorrhage. MicroRNAs (miRNAs) play an important role in posttranscriptional gene expression control, and distinctive patterns of circulating miRNA changes have been identified for some diseases. We aimed to investigate miRNAs that characterize SAH patients with DCI compared with those without DCI.

Methods and Results

Circulating miRNAs were collected on day 7 after SAH in healthy, SAH‐free controls (n=20), SAH patients with DCI (n=20), and SAH patients without DCI (n=20). We used the LASSO (least absolute shrinkage and selection operator) method of regression analysis to characterize miRNAs associated with SAH patients with DCI compared with those without DCI. In the 28 dysregulated miRNAs associated with DCI and SAH, we found that a combination of 4 miRNAs (miR‐4532, miR‐4463, miR‐1290, and miR‐4793) could differentiate SAH patients with DCI from those without DCI with an area under the curve of 100% (95% CI 1.000–1.000, P<0.001). This 4‐miRNA combination could also distinguish SAH patients with or without DCI from healthy controls with areas under the curve of 99.3% (95% CI 0.977–1.000, P<0.001) and 82.0% (95% CI 0.685–0.955, P<0.001), respectively.

Conclusions

We found a 4‐miRNA combination that characterized SAH patients with DCI. The findings could guide future mechanistic study to develop therapeutic targets.

MicroRNAs in bone development and their diagnostic and therapeutic potentials in osteoporosis

MicroRNAs (miRNAs) are small non-coding RNAs approximately 22 nucleotides in length. miRNAs play an important role in the posttranscriptional regulation of gene expression via translational repression and targeting messenger RNA for degradation. In vivo and in vitro evidence has established the importance of miRNAs in physiology and developmental processes such as cell proliferation, differentiation, survival and apoptosis. miRNA dysregulation is associated with the pathogenesis of cardiovascular diseases, metabolic syndromes, and degenerative diseases. An increasing number of miRNAs have been found to play an important role in bone homeostasis. In this review, the roles of miRNAs in the regulation of bone formation and resorption as well as miRNAs that regulate key transcription factors of osteogenesis are discussed. A special emphasis is given to miRNAs whose direct targets have been identified. The miRNAs that contribute to the pathogenesis of osteoporosis and their therapeutic potential are also considered.

Pre-storage centrifugation conditions have significant impact on measured microRNA levels in biobanked EDTA plasma samples

BACKGROUND

In the past few years, an increasing number of studies have reported the potential use of microRNAs (miRNA) as circulating biomarkers for diagnosis or prognosis of a wide variety of diseases. There is, however, a lack of reproducibility between studies. Due to the high miRNA content in platelets this may partly be explained by residual platelets in the plasma samples used. When collecting fresh plasma samples, it is possible to produce cell-free/platelet-poor plasma by centrifugation. In this study, we systematically investigated whether biobanked EDTA plasma samples could be processed to be suitable for miRNA analysis.

MATERIALS AND METHODS

Blood samples were collected from ten healthy volunteers and centrifuged to produce platelet-poor-plasma (PPP) and standard biobank plasma. After one week at -80 °C the biobanked EDTA plasma was re-centrifuged by different steps to remove residual platelets. Using RT-qPCR the levels of 14 miRNAs in the different plasma preparations were compared to that of PPP.

RESULTS

We were able to remove residual platelets from biobanked EDTA plasma by re-centrifugation of the thawed samples. Nevertheless, for most of the investigated miRNAs, the miRNA level was significantly higher in the re-centrifuged biobanked plasma compared to PPP, even when the platelet count was reduced to 0-1×109/L.

CONCLUSION

We found, that pre-storage centrifugation conditions have a significant impact on the measured EDTA plasma level of miRNAs known to be present in platelets. Even for the miRNAs found to be less effected, we showed that a 1.5-3 fold change in plasma levels may possible be caused by or easily overseen due to sample preparation and/or storage.

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

The aim of the present study is to identify microRNAs (miRs) with high potential to be used as biomarkers in plasma and/or serum to clinically diagnose, or provide accurate prognosis for survival in, patients with atherosclerosis, coronary artery disease, and acute coronary syndrome (ACS). A systematic search of published original research yielded a total of 72 studies. After review of the risk of bias of the published studies, according to Cochrane Collaboration and the QUADUAS Group standards, 19 studies were selected. Overall 52 different miRs were reported. In particular, miR-133a/b (5 studies), miR-208a/b (6 studies), and miR-499 (7 studies) were well studied and found to be significant diagnostic and/or prognostic markers across different cardiovascular disease progression stages. miR-1 and miR-145b are potential biomarkers of ACS; miR-1 with higher sensitivity for all acute myocardial infarction (AMI), and miR-145 for STEMI and worse outcome of AMI. But when miRs were studied across different ACS study populations, patients had varying degrees of coronary stenosis, which was identified as an important confounder that limited the ability to quantitatively pool the study results. The identified miRs were found to regulate endothelial function and angiogenesis (miR-1, miR-133), vascular smooth muscle cell differentiation (miR-133, miR-145), communication between vascular smooth muscle and endothelial cell to stabilize plaques (miR-145), apoptosis (miR-1, miR-133, miR-499), cardiac myocyte differentiation (miR-1, miR-133, miR-145, miR-208, miR-499), and to repress cardiac hypertrophy (miR-133). Their role in these processes may be explained by regulation of shared RNA targets such as cyclin-dependent kinase inhibitor 1A (or p21), ETS proto-oncogene 1, fascin actin-bundling protein 1, hyperpolarization-activated cyclic nucleotide-gated potassium channel 4, insulin-like growth factor 1 receptor LIM and SH3 protein 1, purine nucleoside phosphorylase, and transgelin 2. These mechanistic data further support the clinical relevance of the identified miRs. miR-1, miR-133a/b, miR-145, miR-208a/b, and miR-499(a) in plasma and/or serum show some potential for diagnosis of cardiovascular disease. However, biased selection of miRs in most studies and unexplained contrasting results are major limitations of current miR research. Inconsistencies need to be addressed in order to definitively identify clinically useful miRs. Therefore, this paper presents important aspects to improve future miR research, including unbiased selection of miRs, standardization/normalization of reference miRs, adjustment for patient comorbidities and medication, and robust protocols of data-sharing plans that could prevent selective publication and selective reporting of miR research outcomes.