Elevated Plasma Levels of Circulating Extracellular miR-320a-3p in Patients with Paroxysmal Atrial Fibrillation

Correlation between preoperative and postoperative miR-29c-3p level changes and immune response in paediatric acute septic appendicitis and its predictive significance for complications: a retrospective study

BACKGROUND

Postoperative complications in children with acute suppurative appendicitis (ASA) can lead to very serious consequences. In this study, we investigated the pre- and postoperative expression of miR-29c-3p in ASA and its value in predicting postoperative complications.

METHODS

Retrospectively, 128 children with ASA and 93 healthy children were included. The qRT-PCR technique was used to detect miR-29c-3p expression in children with ASA preoperatively and 24 h postoperatively. The levels of immune cells (WBC, NEU, LYM) were detected by routine blood test, and the levels of immune proteins CRP and inflammatory factors (TNF-α and IL-6) were detected by ELISA.

RESULTS

Before surgery, children with ASA had higher levels of miR-29c-3p than healthy controls. But after surgery, miR-29ac-3p levels dropped a lot in children with ASA. The serum levels of immune cells (WBC, NEU, LYM), immune protein CRP and inflammatory factors (TNF-α and IL-6) were significantly decreased in children with ASA. Postoperative miR-29c-3p levels were positively correlated with the levels of immune indicators. The patients with higher miR-29c-3p expression levels showed a greater incidence of postoperative complications.

CONCLUSIONS

The expression of miR-29c-3p was positively correlated to immune cells, immune proteins, and inflammatory factors. The expression levels of miR-29c-3p were related to the occurrence of postoperative complications and could, therefore, be utilized to predict the occurrence of postoperative complications in children with ASA.

Elucidating the preventive and therapeutic effects of cardiac telocytes paracrine microRNAs on ischemic heart disease

Telocytes (TCs), a newly identified type of mesenchymal cell since 2010, possess substantial potential in maintaining tissue homeostasis, orchestrating organ development, and facilitating tissue regeneration. Their distribution in blood, the adventitia of blood vessels, and the intima implies a close association with vascular function. Ischemic heart disease (IHD), a significant challenge in cardiovascular disease, is characterized by the occlusion of major vessels, obstruction of collateral circulation, and disruption of the capillary network-pathological features closely linked to endothelial cell damage. Myocardial tissue is rich in cardiac telocytes (cTCs), which, following myocardial injury, can secrete numerous miRNAs that promote angiogenesis, including miR-let-7e, miR-10a, and miR-126-3p. This indicates that cTCs may have therapeutic potential for IHD. The primary mechanism by which cTCs-derived exosomes exert paracrine effects is through reducing endothelial cell injury, suggesting that enhancing the production of cTCs could offer a novel therapeutic approach for treating IHD.

Restoration effect of chemically modified microRNA-143-3p on acute myocardial infarction in animal models

We investigated whether miR143#12, a synthesized chemically modified miR-143-3p derivative, exerts therapeutic effects on acute myocardial infarction (AMI). Sprague-Dawley rats and Japanese white rabbits underwent 30 min of coronary occlusion followed by 2 weeks of reperfusion. The rat AMI model was intravenously administered with control miRNA (9 μg/kg), 3 μg/kg or 9 μg/kg of miR143#12 1 h after reperfusion, while the rabbit AMI model was intravenously administered with control miRNA (9 μg/kg) or 9 μg/kg of miR143#12. In the rat and rabbit AMI models, 9 μg/kg of miR143#12 significantly reduced infarct sizes and significantly improved cardiac function including LVEF and LVFS at 2 weeks. The tissue miR143 levels in infarct areas significantly decreased after AMI in both models. Electron microscopic study and immunohistochemistry suggested that miR143#12 suppressed autophagic cell death caused by AMI and induced neoangiogenesis in the infarct border. In cultured rat H9c2 cells, miR143#12 significantly inhibited H2O2-induced autophagic cell death by decreasing ROS levels and increased viable cell numbers more than the control by silencing COX-1, -2, and ATG7. Replacement treatment with miR143#12 in the infarct areas, where the expression levels of miR143 were significantly decreased, has a beneficial effect on AMI by silencing COX-1 and -2.

Small RNA signatures of acute ischemic stroke in L1CAM positive extracellular vesicles

L1CAM-positive extracellular vesicles (L1EV) are an emerging biomarker that may better reflect ongoing neuronal damage than other blood-based biomarkers. The physiological roles and regulation of L1EVs and their small RNA cargoes following stroke is unknown. We sought to characterize L1EV small RNAs following stroke and assess L1EV RNA signatures for diagnosing stroke using weighted gene co-expression network analysis and random forest (RF) machine learning algorithms. Interestingly, small RNA sequencing of plasma L1EVs from patients with stroke and control patients (n = 28) identified micro(mi)RNAs known to be enriched in the brain. Weighted gene co-expression network analysis (WGCNA) revealed small RNA transcript modules correlated to diagnosis, initial NIH stroke scale, and age. L1EV RNA signatures associated with the diagnosis of AIS were derived from WGCNA and RF classification. These small RNA signatures demonstrated a high degree of accuracy in the diagnosis of AIS with an area under the curve (AUC) of the signatures ranging from 0.833 to 0.932. Further work is necessary to understand the role of small RNA L1EV cargoes in the response to brain injury, however, this study supports the utility of L1EV small RNA signatures as a biomarker of stroke.

Predictive Value of Serum microRNA-29b-3p in Recurrence of Atrial Fibrillation After Radiofrequency Catheter Ablation

Objective

Atrial fibrillation (AF) is a common arrhythmia. This study explored serum miR-29b-3p expression in AF patients and its value in predicting AF recurrence after radiofrequency catheter ablation (RFCA).

Methods

Totally 100 AF patients who underwent RFCA were enrolled, with 100 individuals without AF as controls. Serum miR-29b-3p expression in participants was determined using RT-qPCR. The correlation between miR-29b-3p and atrial fibrosis markers (FGF-21/FGF-23) was assessed by Pearson analysis. The diagnostic efficacy of serum miR-29b-3p and FGF-21/FGF-23 in predicting AF recurrence after RFCA was analyzed by the receiver operating characteristic (ROC) curves. The Kaplan-Meier method was adopted to evaluate the effect of miR-29b-3p expression on the incidence of AF recurrence after RFCA. The independent risk factors for AF recurrence after RFCA were analyzed by logistic regression analysis.

Results

Serum miR-29b-3p was poorly expressed in AF patients. After RFCA, AF patients showed elevated serum miR-29b-3p expression. Serum miR-29b-3p expression in AF patients negatively correlated with serum FGF-21 and FGF-23 concentrations. The cut-off values of serum miR-29b-3p, FGF-21, and FGF-23 in identifying AF recurrence were 0.860 (sensitivity: 100.00%, specificity: 39.71%), 222.2 pg/mL (sensitivity: 96.88%, specificity: 32.35%) and 216.3 ng/mL (sensitivity: 53.13%, specificity: 70.59%), respectively. Patients with low miR-29b-3p expression had a significantly higher incidence of AF recurrence than patients with high miR-29b-3p expression. Serum miR-29b-3p expression was one of the independent risk factors for AF recurrence after RFCA.

Conclusion

Low miR-29b-3p expression in AF patients has certain predictive values and is one of the independent risk factors for AF recurrence after RFCA.

miR-29b-1-5p exacerbates myocardial injury induced by sepsis in a mouse model by targeting TERF2

Myocardial damage is a critical complication and a significant contributor to mortality in sepsis. MicroRNAs (miRNAs) have emerged as key players in sepsis pathogenesis. In this study, we explore the effect and mechanisms of miR-29b-1-5p on sepsis-induced myocardial damage. Sepsis-associated Gene Expression Omnibus datasets (GSE72380 and GSE29914) are examined for differential miRNAs. The mouse sepsis-induced cardiac injury was established by Lipopolysaccharide (LPS) or cecal ligation and puncture (CLP). LPS-treated HL-1 mouse cardiomyocytes simulate myocardial injury in vitro. miR-29b-1-5p is co-upregulated in both datasets and in cardiac tissue from sepsis mouse and HL-1 cell models. miR-29b-1-5p expression downregulation was achieved by antagomir transduction and confirmed by real-time quantitative reverse transcription PCR. Survival analysis and echocardiography examination show that miR-29b-1-5p inhibition improves mice survival cardiac function in LPS- and CLP-induced sepsis mice. Hematoxylin and eosin and Masson's trichrome staining and Immunohistochemistry analysis of mouse myocardial α-smooth muscle actin show that miR-29b-1-5p inhibition reduces myocardial tissue injury and fibrosis. The inflammatory cytokines and cardiac troponin I (cTnI) levels in mouse serum and HL-1 cells are also decreased by miR-29b-1-5p inhibition, as revealed by enzyme-linked immunosorbent assay. The expressions of autophagy-lysosomal pathway-related and apoptosis-related proteins in the mouse cardiac tissues and HL-1 cells are evaluated by western blot analysis. The sepsis-induced activation of the autophagy-lysosomal pathway and apoptosis are also reversed by miR-29b-1-5p antagomir. MTT and flow cytometry measurement further confirm the protective role of miR-29b-1-5p antagomir in HL-1 cells by increasing cell viability and suppressing cell apoptosis. Metascape functionally enriches TargetScan-predicted miR-29b-1-5p target genes. TargetScan prediction and dual luciferase assay validate the targeting relationship between miR-29b-1-5p and telomeric repeat-binding factor 2 (TERF2). The expression and function of TERF2 in HL-1 cells and mice are also evaluated. MiR-29b-1-5p negatively regulates the target gene TERF2. TERF2 knockdown partly restores miR-29b-1-5p antagomir function in LPS-stimulated HL-1 cells. In summary, miR-29b-1-5p targetedly inhibits TERF2, thereby enhancing sepsis-induced myocardial injury.

MicroRNA hsa-miR-320a-3p and Its Targeted mRNA FKBP5 Were Differentially Expressed in Patients with HIV/TB Co-Infection

Among the PLWH (people living with HIV) population, the risk of developing active tuberculosis (TB) is increasing. Active TB also accelerates the deterioration of PLWH's immune function and is one of the leading causes of death in the PLWH population. So far, accurate diagnosis of active TB in the PLWH population remains challenging. Through data analysis of HIV/TB co-infection in the GEO database, the differentially expressed genes as well as their related microRNA (miRNA) were acquired and were further verified through clinical blood samples. Dual-luciferase assay was used to verify the mechanism of miRNA on mRNA. The enrichment of immune cells in database patient samples was analyzed by bioinformatics and finally verified by blood routine data. Our study found that FKBP5 (FK506 binding protein 5) was highly expressed in the HIV/TB co-infection group; hsa-miR-320a-3p was highly expressed in the HIV infection group but decreased in the HIV/TB co-infection group. Dual-luciferase assay results showed that hsa-miR-320a-3p mimics significantly reduced the relative luciferase activity of the WT-FKBP5 group; however, this phenomenon was not observed in the MUT-FKBP5 group. At the same time, as a key molecule of the immune-related pathway, FKBP5 is highly correlated with the amount of neutrophils, which provides a new suggestion for the treatment of the HIV/TB co-infection population. Our study found that hsa-miR-320a-3p can decrease FKBP5 expression, suggesting a potential regulatory role for FKBP5. The involvement of FKBP5 and its related molecule hsa-miR-320a-3p in HIV/TB co-infection proposes them as potential biomarkers for the diagnosis of active TB in the PLWH population.

Research progress of non-coding RNA in atrial fibrillation

Atrial fibrillation (AF) is a common arrhythmia in clinic, and its incidence is increasing year by year. In today's increasingly prevalent society, ageing poses a huge challenge to global healthcare systems. AF not only affects patients' quality of life, but also causes thrombosis, heart failure and other complications in severe cases. Although there are some measures for the diagnosis and treatment of AF, specific serum markers and targeted therapy are still lacking. In recent years, ncRNAs have become a hot topic in cardiovascular disease research. These ncRNAs are not only involved in the occurrence and development of AF, but also in pathophysiological processes such as myocardial infarction and atherosclerosis, and are potential biomarkers of cardiovascular diseases. We believe that the understanding of the pathophysiological mechanism of AF and the study of diagnosis and treatment targets can form a more systematic diagnosis and treatment framework of AF and provide convenience for individuals with AF and the society.

Utilizing MiSeq Sequencing to Detect Circulating microRNAs in Plasma for Improved Lung Cancer Diagnosis

Non-small cell lung cancer (NSCLC) is a major contributor to cancer-related deaths, but early detection can reduce mortality. NSCLC comprises mainly adenocarcinoma (AC) and squamous cell carcinoma (SCC). Circulating microRNAs (miRNAs) in plasma have emerged as promising biomarkers for NSCLC. However, existing techniques for analyzing miRNAs have limitations, such as restricted target detection and time-consuming procedures. The MiSeqDx System has been shown to overcome these limitations, making it a promising tool for routine clinical settings. We investigated whether the MiSeqDx could profile cell-free circulating miRNAs in plasma and diagnose NSCLC. We sequenced RNA from the plasma of patients with AC and SCC and from cancer-free smokers using the MiSeqDx to profile and compare miRNA expressions. The MiSeqDx exhibits high speed and accuracy when globally analyzing plasma miRNAs. The entire workflow, encompassing RNA to data analysis, was completed in under three days. We also identified panels of plasma miRNA biomarkers that can diagnose NSCLC with 67% sensitivity and 68% specificity, and detect SCC with 90% sensitivity and 94% specificity, respectively. This study is the first to demonstrate that rapid profiling of plasma miRNAs using the MiSeqDx has the potential to offer a straightforward and effective method for the early detection and classification of NSCLC.

Circulating plasma and exosome levels of the miR-320 family as a non-invasive biomarker for methamphetamine use disorder

The neurobiological mechanism underlying methamphetamine (MA) use disorder was still unclear, and no specific biomarker exists for clinical diagnosis of this disorder. Recent studies have demonstrated that microRNAs (miRNAs) are involved in the pathological process of MA addiction. The purpose of this study was to identify novel miRNAs for the diagnosis biomarkers of MA user disorder. First, members of the miR-320 family, including miR-320a-3p, miR-320b, and miR-320c, were screened and analyzed in the circulating plasma and exosomes by microarray and sequencing. Secondly, plasma miR-320 was quantified by real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) in eighty-two MA patients and fifty age-gender-matched healthy controls. Meanwhile, we also analyzed exosomal miR-320 expression in thirty-nine MA patients and twenty-one age-matched healthy controls. Furthermore, the diagnostic power was evaluated using the area under the curve (AUC) of the receiver operating characteristic (ROC) curve. The expression of miR-320 significantly increased in plasma and exosomes of MA patients compared with healthy controls. The AUC of the ROC curves of miR-320 in plasma and exosomes of MA patients were 0.751 and 0.962, respectively. And the sensitivities of miR-320 were 0.900 and 0.846, respectively, whereas the specificities of miR-320 were 0.537 and 0.952, respectively, in plasma and exosomes in MA patients. And the increased plasma miR-320 was positively correlated with cigarette smoking, age of onset, and daily use of MA in MA patients. Finally, cardiovascular disease, synaptic plasticity, and neuroinflammation were predicted to be the target pathways related to miR-320. Taken together, our findings indicated that plasma and exosomal miR-320 might be used as a potential blood-based biomarker for diagnosing MA use disorder.

Circulating miR-320a-3p and miR-483-5p level associated with pharmacokinetic-pharmacodynamic profiles of rivaroxaban

BACKGROUND

Novel biomarkers for personalizing anticoagulation remain undetermined. We aimed to investigate the association of plasma miRNAs with pharmacokinetic-pharmacodynamic (PK-PD) profiles of rivaroxaban.

METHODS

This is a multicenter, exploratory study of miRNAs in a Chinese population. Healthy volunteers and patients receiving rivaroxaban were enrolled in the study. The area under the plasma concentration-time curve from time 0-t h (AUC_0-t) and anti-Xa activity at 3 h (AXA_3h) were measured in healthy volunteers, and AXA_3h was measured in patients. MiRNAs were detected by miRNA microarray in 26 healthy volunteers with 20 mg rivaroxaban, and quantitative reverse transcription polymerase chain reaction was used to exclude undetectable ones. MiR-320a-3p and miR-483-5p were then quantified in 65 healthy volunteers and 71 patients. MiRNA levels at 3 h were compared between high and low AXA_3h or AUC_0-t subjects and in matched patients with or without bleeding during follow-up. The miRNA targets were predicted by TargetScan, miRTarBase, and miRDB. Validated genes were included in GO enrichment and KEGG analyses. The protein-protein interaction network was established by STRING and visualized by Cytoscape.

RESULTS

A total of 136 Chinese subjects completed the study. In healthy volunteers taking 15 mg rivaroxaban, the miR-320a level at 3 h was significantly positively correlated with AXA_3h and AUC_0-t (r = 0.359, p = 0.025; r = 0.370, p = 0.02, respectively). A positive correlation was also observed between miR-483 and AXA_3h or AUC_0-t (r = 0.372, p = 0.02; r = 0.523, p = 0.001, respectively). MiR-320a and miR-483 levels at 3 h in the higher AUC_0-t group were significantly higher than those at 0 h. MiR-483 levels at 3 h may distinguish healthy volunteers with high or low AXA_3h or AUC_0-t. In the 10 mg fed subgroup, higher 3 h mir-483 levels were also observed compared with the control group. No significant differences were found in the comparisons among patients. Bioinformatic analysis showed that these miRNAs may play a regulatory role by targeting ABCG2, ITGB3, PTEN, MAPK1/3, etc. CONCLUSIONS: MiR-320a and miR-483 levels were found to be associated with PK and PD profiles of rivaroxaban in healthy Chinese subjects. Further studies are required to verify these findings and explore the mechanisms.

Plasma levels of miRNA-1-3p are associated with subclinical atrial fibrillation in patients with cryptogenic stroke

INTRODUCTION AND OBJECTIVES

Identifying biomarkers of subclinical atrial fibrillation (AF) is of most interest in patients with cryptogenic stroke (CrS). We sought to evaluate the circulating microRNA (miRNA) profile of patients with CrS and AF compared with those in persistent sinus rhythm.

METHODS

Among 64 consecutive patients with CrS under continuous monitoring by a predischarge insertable monitor, 18 patients (9 with AF and 9 in persistent sinus rhythm) were selected for high-throughput determination of 754 miRNAs. Nine patients with concomitant stroke and AF were also screened to improve the yield of miRNA selection. Differentially expressed miRNAs were replicated in an independent cohort (n=46). Biological markers were stratified by the median and included in logistic regression analyses to evaluate their association with AF at 6 and 12 months.

RESULTS

Eight miRNAs were differentially expressed between patients with and without AF. In the replication cohort, miR-1-3p, a gene regulator involved in cardiac arrhythmogenesis, was the only miRNA to remain significantly higher in patients with CrS and AF vs those in sinus rhythm and showed a modest association with AF burden. High (= above the median) miR-1-3p plasma values, together with a low left atrial ejection fraction, were independently associated with the presence of AF at 6 and 12 months.

CONCLUSIONS

In this cohort, plasma levels of miR-1-3p were elevated in CrS patients with subsequent AF. Our results preliminarily suggest that miR-1-3p could be a novel biomarker that, together with clinical parameters, could help identify patients with CrS and a high risk of occult AF.

Upregulated miR-328-3p and its high risk in atrial fibrillation: A systematic review and meta-analysis with meta-regression

BACKGROUND

Several studies have shown miR-328-3p increased in atrial fibrillation (AF), but some researches indicated no difference or even decreased. This inconsistent result confuses researchers, and it is urgent to know the truth. This study is to assess the association between miR-328-3p levels in plasma/atrial tissue and patients with AF.

METHODS

PubMed, EMBASE, Scopus, Web of Science, and ProQuest were searched from inception to February 1, 2021. The standardized mean differences (SMD) with their 95% confidence interval (CI) were calculated to evaluate the association between miR-328-3p levels and AF.

RESULTS

Twelve studies met the inclusion criteria and were used for our meta-analysis. Overall, the levels of miR-328-3p were higher in patients with AF than in the control group (SMD = 0.69, 95% CI [0.10, 1.28], P = .022). After adjustment, the overall SMD was 0.82 (95% CI [0.22, 1.42], P = .007). Sensitivity analysis indicated that the results were stable, and the trim-fill analysis showed that the results were credible. Subgroup analyses showed that AF patients, n ≥ 30, various of comorbidity, articles published earlier, and Asia groups had higher levels of expression of miR-328-3p.

CONCLUSIONS

High levels of miR-328-3p are significantly associated with an increased risk of AF. It implies that miR-328-3p played an important role in diagnosis and may serve as a potential momentous, and useful biomarker to identify AF.

Atrial Fibrillation: Pathogenesis, Predisposing Factors, and Genetics

Atrial fibrillation (AF) is the most frequent arrhythmia managed in clinical practice, and it is linked to an increased risk of death, stroke, and peripheral embolism. The Global Burden of Disease shows that the estimated prevalence of AF is up to 33.5 million patients. So far, successful therapeutic techniques have been implemented, with a high health-care cost burden. As a result, identifying modifiable risk factors for AF and suitable preventive measures may play a significant role in enhancing community health and lowering health-care system expenditures. Several mechanisms, including electrical and structural remodeling of atrial tissue, have been proposed to contribute to the development of AF. This review article discusses the predisposing factors in AF including the different pathogenic mechanisms, sedentary lifestyle, and dietary habits, as well as the potential genetic burden.

A narrative review of non-coding RNAs in atrial fibrillation: potential therapeutic targets and molecular mechanisms

Objective

This review summarizes the advances in the study of ncRNAs and atrial remodeling mechanisms to explore potential therapeutic targets and strategies for AF.

Background

Atrial fibrillation (AF) is one of the most common arrhythmias, and its morbidity and mortality rates are gradually increasing. Non-coding ribonucleic acid RNAs (ncRNAs) are transcribed from the genome and do not have the ability to be translated into proteins. A growing body of evidence has shown ncRNAs are extensively involved in the pathophysiological processes underlying AF. However, the precise molecular mechanisms of these associations have not been fully elucidated. Atrial remodeling plays a key role in the occurrence and development of AF, and includes electrical remodeling, structural remodeling, and autonomic nerve remodeling. Research has shown that ncRNA expression is altered in the plasma and tissues of AF patients that mediate cardiac excitation and arrhythmia, and is closely related to atrial remodeling.

Methods

Literatures about ncRNAs and atrial fibrillation were extensively reviewed to discuss and analyze.

Conclusions

The biology of ncRNAs represents a relatively new field of research and is still in an emerging stage. Recent studies have laid a foundation for understanding the molecular mechanisms of AF, future studies aimed at identifying how ncRNAs act on atrial fibrillation to provide potentially promising therapeutic targets for the treatment of atrial fibrillation.

Upregulation of miR‑335 exerts protective effects against sepsis‑induced myocardial injury

Septicemia is associated with excessive inflammation, oxidative stress and apoptosis, causing myocardial injury that results in high mortality and disability rates worldwide. The abnormal expression of multiple microRNAs (miRNAs/miRs) is associated with more severe sepsis‑induced myocardial injury (SIMI) and miR‑335 has been shown to protect cardiomyocytes from oxidative stress. The present study aimed to investigate the role of miR‑335 in SIMI. An SIMI model was established by cecal ligation and puncture (CLP) in mice. An miRNA‑335 precursor (pre‑miR‑335) was transfected to accelerate miR‑335 expression and an miR‑335 inhibitor (anti‑miR‑335) was used to inhibit miR‑335 expression. CLP or sham surgery was performed on pre‑miR‑335, anti‑miR‑335 and wild‑type mice and miR‑335 expression was determined by reverse transcription‑quantitative PCR. Inflammatory factors (TNF‑α, IL‑6 and IL‑10) and troponin (cTNI), brain natriuretic peptide (BNP), creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) were assessed using commercial kits. Apoptosis was detected by flow cytometry and cardiac function was assessed using a Langendorff isolated cardiac perfusion system. miR‑335 expression was upregulated and an elevation in inflammatory factors and cTNI, BNP, CK, LDH and AST was observed. Compared with the wild‑type control group, pre‑miR‑335 mice treated with CLP exhibited significantly reduced left ventricular development pressure, maximum pressure increased reduction rates, as well as decreased levels of TNF‑α, IL‑6 and IL‑10, myocardial injury and apoptosis; by contrast, these features were amplified in CLP‑treated anti‑miR‑335 mice. In conclusion, the upregulation of miR‑335 exerted ameliorative effects on myocardial injury following sepsis and may indicate a novel therapeutic intervention for SIMI.

LncRNA TUG1 Regulates Proliferation of Cardiac Fibroblast via the miR-29b-3p/TGF-β1 Axis

Background: Atrial fibrillation (AF) is a very common clinical arrhythmia, accompanied by the overproliferation of cardiac fibroblasts (CFs). This study aimed to investigate the role of the long non-coding RNA(lncRNA) taurine upregulated gene 1 (TUG1) in the proliferation of CFs and further investigated its underlying mechanism.

Methods: One hundred four paroxysmal AF patients and 94 healthy controls were recruited. Human cardiac fibroblasts (HCFs) were applied to establish an AF cell model through treatment with angiotensin II (AngII). qRT-PCR was used for the measurement of gene levels. The cell proliferation was detected by cell counting kit-8 (CCK-8). Luciferase reporter assay was performed for target gene analysis.

Results: Elevated levels of TUG1 and low expression of miR-29b-3p were detected in the serum of AF patients compared with the healthy controls. Pearson's correlation analysis exhibited an inverse relationship between TUG1 and miR-29b-3p expression in AF patients (r = −7.106, p < 0.001). Knockdown of TUG1 inhibited AngII-induced CF proliferation. Taurine upregulated gene 1 (TUG1) functions as a competing endogenous RNA (ceRNA) for miR-29b-3p, and downregulation of miR-29b-3p reversed the role of TUG1 in CF proliferation. TGF-β1 is a direct target gene of miR-29b-3p.

Conclusions: Long non-coding RNA taurine upregulated gene 1 is a key regulator in the occurrence of AF. Slicing TUG1 inhibits CF proliferation by regulating the miR-29b-3p/TGF-β1 axis.

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.

Adipocyte, Immune Cells, and miRNA Crosstalk: A Novel Regulator of Metabolic Dysfunction and Obesity

Obesity is characterized as a complex and multifactorial excess accretion of adipose tissue (AT) accompanied with alterations in the immune response that affects virtually all age and socioeconomic groups around the globe. The abnormal accumulation of AT leads to several metabolic diseases, including nonalcoholic fatty liver disorder (NAFLD), low-grade inflammation, type 2 diabetes mellitus (T2DM), cardiovascular disorders (CVDs), and cancer. AT is an endocrine organ composed of adipocytes and immune cells, including B-Cells, T-cells and macrophages. These immune cells secrete various cytokines and chemokines and crosstalk with adipokines to maintain metabolic homeostasis and low-grade chronic inflammation. A novel form of adipokines, microRNA (miRs), is expressed in many developing peripheral tissues, including ATs, T-cells, and macrophages, and modulates the immune response. miRs are essential for insulin resistance, maintaining the tumor microenvironment, and obesity-associated inflammation (OAI). The abnormal regulation of AT, T-cells, and macrophage miRs may change the function of different organs including the pancreas, heart, liver, and skeletal muscle. Since obesity and inflammation are closely associated, the dysregulated expression of miRs in inflammatory adipocytes, T-cells, and macrophages suggest the importance of miRs in OAI. Therefore, in this review article, we have elaborated the role of miRs as epigenetic regulators affecting adipocyte differentiation, immune response, AT browning, adipogenesis, lipid metabolism, insulin resistance (IR), glucose homeostasis, obesity, and metabolic disorders. Further, we will discuss a set of altered miRs as novel biomarkers for metabolic disease progression and therapeutic targets for obesity.