Prospective and therapeutic screening value of non-coding RNA as biomarkers in cardiovascular disease

CXCR4 - a possible serum marker for risk stratification of abdominal aortic aneurysms

Background: Abdominal aortic aneurysm (AAA) rupture is still associated with a mortality rate of 80-90%. Imaging techniques or molecular fingerprinting for patient-specific risk stratification to identify pending rupture are still lacking. The chemokine (C-X-C motif) receptor (CXCR4) activation by CXCL12 ligand has been identified as a marker of inflammation and atherosclerosis, associated with AAA. Both are highly expressed in the aortic aneurysm wall. However, it is still unclear whether different expression levels of CXCR4 and CXCL12 can distinguish ruptured AAAs (rAAA) from intact AAAs (iAAA). Patients and methods: Abdominal aortic tissue samples (rAAA: n=29; iAAA: n=54) were excised during open aortic repair. Corresponding serum samples from these patients (n=9 from rAAAs; n=47 from iAAA) were drawn pre-surgery. Healthy aortic tissue samples (n=8) obtained from adult kidney donors during transplantation and serum samples from healthy adult volunteers were used as controls (n=5 each). Results: CXCR4 was mainly expressed in the media of the aneurysmatic tissue. Focal positive staining was also observed in areas of inflammatory infiltrates within the adventitia. In tissue lysates, no significant differences between iAAA, rAAA, and healthy controls were observed upon ELISA analysis. In serum samples, the level of CXCR4 was significantly increased in rAAA by 4-fold compared to healthy controls (p=0.011) and 3.0-fold for rAAA compared to iAAA (p<0.001). Furthermore a significant positive correlation between aortic diameter and serum CXCR4 concentration was found for both, iAAA and rAAA (p=0.042). Univariate logistic regression analysis showed that increased CXCR4 serum concentrations were associated with AAA rupture (OR: 4.28, 95% CI: 1.95-12.1, p=0.001). Conclusions: CXCR4 concentration was significantly increased in serum of rAAA patients and showed a significant correlation with an increased aortic diameter. The level of CXCR4 in serum was associated with a more than 4-fold risk increase for rAAA and thus could possibly serve as a biomarker in the future. However, further validation in larger studies is required.

Using ncRNAs as Tools in Cancer Diagnosis and Treatment-The Way towards Personalized Medicine to Improve Patients' Health

Although the first discovery of a non-coding RNA (ncRNA) dates back to 1958, only in recent years has the complexity of the transcriptome started to be elucidated. However, its components are still under investigation and their identification is one of the challenges that scientists are presently facing. In addition, their function is still far from being fully understood. The non-coding portion of the genome is indeed the largest, both quantitatively and qualitatively. A large fraction of these ncRNAs have a regulatory role either in coding mRNAs or in other ncRNAs, creating an intracellular network of crossed interactions (competing endogenous RNA networks, or ceRNET) that fine-tune the gene expression in both health and disease. The alteration of the equilibrium among such interactions can be enough to cause a transition from health to disease, but the opposite is equally true, leading to the possibility of intervening based on these mechanisms to cure human conditions. In this review, we summarize the present knowledge on these mechanisms, illustrating how they can be used for disease treatment, the current challenges and pitfalls, and the roles of environmental and lifestyle-related contributing factors, in addition to the ethical, legal, and social issues arising from their (improper) use.

Regulation of Endothelial Progenitor Cell Functions in Ischemic Heart Disease: New Therapeutic Targets for Cardiac Remodeling and Repair

Ischemic heart disease (IHD) is the leading cause of morbidity and mortality worldwide. Ischemia and hypoxia following myocardial infarction (MI) cause subsequent cardiomyocyte (CM) loss, cardiac remodeling, and heart failure. Endothelial progenitor cells (EPCs) are involved in vasculogenesis, angiogenesis and paracrine effects and thus have important clinical value in alternative processes for repairing damaged hearts. In fact, this study showed that the endogenous repair of EPCs may not be limited to a single cell type. EPC interactions with cardiac cell populations and mesenchymal stem cells (MSCs) in ischemic heart disease can attenuate cardiac inflammation and oxidative stress in a microenvironment, regulate cell survival and apoptosis, nourish CMs, enhance mature neovascularization, alleviate adverse ventricular remodeling after infarction and enhance ventricular function. In this review, we introduce the definition and discuss the origin and biological characteristics of EPCs and summarize the mechanisms of EPC recruitment in ischemic heart disease. We focus on the crosstalk between EPCs and endothelial cells (ECs), smooth muscle cells (SMCs), CMs, cardiac fibroblasts (CFs), cardiac progenitor cells (CPCs), and MSCs during cardiac remodeling and repair. Finally, we discuss the translation of EPC therapy to the clinic and treatment strategies.

ZNF561-AS1 Regulates Cell Proliferation and Apoptosis in Myocardial Infarction Through miR-223-3p/NLRP3 Axis

Long non-coding RNAs (lncRNAs) have been widely recognized as important regulators in myocardial infarction (MI) and other heart diseases. Our study aimed to investigate the mechanism and biological function of an unknown lncRNA zinc finger protein 561 antisense RNA 1 (ZNF561-AS1) in MI. After confirming the MI model was successful, we applied reverse transcription quantitative polymerase chain reaction and Western blot (WB) and found that the expression of NLR family pyrin domain containing 3 (NLRP3), interleukin (IL)-1β, and IL-18 was substantially increased in infarct and border zones of MI mice heart at 24 h and 72 h compared with that in sham-operated models. Moreover, we found that NLRP3 expression was promoted in hypoxia human cardiomyocytes (HCMs). Through cell function assays including CCK-8, 5-Ethynyl-2’-deoxyuridine (EdU), flow cytometry, and TdT-mediated dUTP Nick-End Labeling (TUNEL), supported by WB analysis, we verified that silencing of NLRP3 facilitated proliferation but impeded apoptosis of hypoxia-induced myocardial cell. Moreover, Ago2-RIP and RNA pull-down assays displayed that NLRP3 could combine with miR-223-3p. Luciferase reporter assays further confirmed that NLRP3 was directly targeted by miR-223-3p. Simultaneously, we found that miR-223-3p was the downstream gene of ZNF561-AS1. In addition, we conducted a series of rescue experiments to affirm that ZNF561-AS1 regulated cell proliferation and apoptosis in MI through miR-223-3p/NLRP3 axis.

NcRNAs in Vascular and Valvular Intercellular Communication

Non-coding RNAs have been shown to be important biomarkers and mediators of many different disease entities, including cardiovascular (CV) diseases like atherosclerosis, aneurysms, and valvulopathies. Growing evidence suggests a central role of ncRNAs as regulators of different pathological pathways involved in endothelial dysfunction, cardiovascular inflammation, cell differentiation, and calcification. This review will discuss the role of protein-bound and extracellular vesicular-bound ncRNAs as biomarkers of vascular and valvular diseases, their role as intercellular communicators, and regulators of disease pathways and also highlights possible treatment strategies.

Circulating Biomarkers for Cardiovascular Disease Risk Prediction in Patients With Cardiovascular Disease

Cardiovascular disease (CVD) is the leading cause of death globally. Risk assessment is crucial for identifying at-risk individuals who require immediate attention as well as to guide the intensity of medical therapy to reduce subsequent risk of CVD. In the past decade, many risk prediction models have been proposed to estimate the risk of developing CVD. However, in patients with a history of CVD, the current models that based on traditional risk factors provide limited power in predicting recurrent cardiovascular events. Several biomarkers from different pathophysiological pathways have been identified to predict cardiovascular events, and the incorporation of biomarkers into risk assessment may contribute to enhance risk stratification in secondary prevention. This review focuses on biomarkers related to cardiovascular and metabolic diseases, including B-type natriuretic peptide, high-sensitivity cardiac troponin I, adiponectin, adipocyte fatty acid-binding protein, heart-type fatty acid-binding protein, lipocalin-2, fibroblast growth factor 19 and 21, retinol-binding protein 4, plasminogen activator inhibitor-1, 25-hydroxyvitamin D, and proprotein convertase subtilisin/kexin type 9, and discusses the potential utility of these biomarkers in cardiovascular risk prediction among patients with CVD. Many of these biomarkers have shown promise in improving risk prediction of CVD. Further research is needed to assess the validity of biomarker and whether the strategy for incorporating biomarker into clinical practice may help to optimize decision-making and therapeutic management.

Construction of the gene expression subgroups of patients with coronary artery disease through bioinformatics approach

Coronary artery disease (CAD) is a heterogeneous disease that has placed a heavy burden on public health due to its considerable morbidity, mortality and high costs. Better understanding of the genetic drivers and gene expression clustering behind CAD will be helpful for the development of genetic diagnosis of CAD patients. The transcriptome of 352 CAD patients and 263 normal controls were obtained from the Gene Expression Omnibus (GEO) database. We performed a modified unsupervised machine learning algorithm to group CAD patients. The relationship between gene modules obtained through weighted gene co-expression network analysis (WGCNA) and clinical features was identified by the Pearson correlation analysis. The annotation of gene modules and subgroups was done by the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Three gene expression subgroups with the clustering score of greater than 0.75 were constructed. Subgroup I may experience coronary artery disease of an in-creased severity, while subgroup III is milder. Subgroup I was found to be closely related to the upregulation of the mitochondrial autophagy pathway, whereas the genes of subgroup II were shown to be related to the upregulation of the ribosome pathway. The high expression of APOE, NOS1 and NOS3 in the subgroup I suggested that the patients had more severe coronary artery disease. The construction of genetic subgroups of CAD patients has enabled clinicians to improve their understanding of CAD pathogenesis and provides potential tools for disease diagnosis, classification and assessment of prognosis.

CAD increases the long noncoding RNA PUNISHER in small extracellular vesicles and regulates endothelial cell function via vesicular shuttling

Long noncoding RNAs (lncRNAs) have emerged as biomarkers and regulators of cardiovascular disease. However, the expression pattern of circulating extracellular vesicle (EV)-incorporated lncRNAs in patients with coronary artery disease (CAD) is still poorly investigated. A human lncRNA array revealed that certain EV-lncRNAs are significantly dysregulated in CAD patients. Circulating small EVs (sEVs) from patients with (n = 30) or without (n = 30) CAD were used to quantify PUNISHER (also known as AGAP2-antisense RNA 1 [AS1]), GAS5, MALAT1, and H19 RNA levels. PUNISHER (p = 0.002) and GAS5 (p = 0.02) were significantly increased in patients with CAD, compared to non-CAD patients. Fluorescent labeling and quantitative real-time PCR of sEVs demonstrated that functional PUNISHER was transported into the recipient cells. Mechanistically, the RNA-binding protein, heterogeneous nuclear ribonucleoprotein K (hnRNPK), interacts with PUNISHER, regulating its loading into sEVs. Knockdown of PUNISHER abrogated the EV-mediated effects on endothelial cell (EC) migration, proliferation, tube formation, and sprouting. Angiogenesis-related gene profiling showed that the expression of vascular endothelial growth factor A (VEGFA) RNA was significantly increased in EV recipient cells. Protein stability and RNA immunoprecipitation indicated that the PUNISHER-hnRNPK axis regulates the stability and binding of VEGFA mRNA to hnRNPK. Loss of PUNISHER in EVs abolished the EV-mediated promotion of VEGFA gene and protein expression. Intercellular transfer of EV-incorporated PUNISHER promotes a pro-angiogenic phenotype via a VEGFA-dependent mechanism.

LncRNA H19 Regulates Proliferation, Apoptosis and ECM Degradation of Aortic Smooth Muscle Cells Via miR-1-3p/ADAM10 Axis in Thoracic Aortic Aneurysm

Thoracic aortic aneurysm (TAA) is a prevalent health problem worldwide. Long non-coding RNA H19was highly expressed in TAA patients, but the function and mechanism of H19 in TAA remain unknown. The expression levels of H19, microRNA-1-3p (miR-1-3p), and a disintegrin and metalloproteinase 10 (ADAM10) were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Receiver operating characteristic (ROS) cure was performed to evaluate the diagnostic value of H19 on TAA patients. Proliferation and apoptosis were detected by Cell Counting Kit-8 (CCK-8), colony formation, and flow cytometry. Protein levels of proliferating cell nuclear antigen (PCNA), Cleaved-caspase 3 (Cleaved-cas3), Cleaved-caspase 9 (Cleaved-cas9), Collagen I, Collagen III, and ADAM10 were tested by western blot assay. The binding relationship between miR-1-3p and H19 or ADAM10 was predicted by LncBase Predicted v.2 or Starbase, and verified by the dual-luciferase reporter, RNA pull-down assay, and RNA Immunoprecipitation (RIP) assays. H19 was increased in TAA aorta tissues and serum and vascular smooth muscle cell (VSMC), and hindered proliferation as well as promoted apoptosis and extracellular matrix (ECM) degradation of VSMC. Moreover, miR-1-3p was decreased, and ADAM10 was upregulated in TAA aorta tissues and VSMC. The mechanical analysis confirmed that H19 affected ADAM10 expression by targeting miR-1-3p. Our results indicated that H19 inhibited proliferation, and accelerated apoptosis and ECM degradation of VSMC, providing an underlying lncRNA-targeted therapy for TAA treatment.

LncRNA-Malat1 promoting inflammatory response aggravates cerebral ischemia-reperfusion neuronal injury in rats by targeting miR-211-5p

BACKGROUND

Ischemic stroke is one kind of disorder of cerebral blood circulation, which poses a severe threaten to human health and quality of life, causing serious economic loss to families and society. LncRNA-Malat1(Metastasis-associated lung adenocarcinoma transcript 1) and miRNA-211-5p are abnormally expressed in stroke patients and in the middle cerebral ischemia-reperfusion injury (CIRI) model. However, the involvement between LncRNA-Malat1 and miR-211-5p in cerebral ischemia-reperfusion neuronal injury and its mechanism remain unclear.

METHODS

The middle cerebral ischemia-reperfusion injury (CIRI) model was established in rat, and the rat primary neuron injury model induced by oxygen-glucose deprivation/reoxygenation (OGD/R) was simulated in vitro. Level of LncRNA-Malat1, miR-211-5p and COX-2 mRNA were detected via RT-qPCR. The protein levels of COX-2, BAX and BCL-2 were measured by western blot. MTT assay was performed to detect cell viability.

RESULTS

In our study, LncRNA-Malat1 and COX-2 were up-regulated while miR-211-5p down-regulated in vitro and in vivo. Knockdown of LncRNA-Malat1 improved neurological deficit scores, reduced cerebral infarction volume in vivo, and significantly promoted cell viability, reduced apoptosis and proinflammatory factors PGE2 and IL-10 in vitro. More importantly, the level of miR-211-5p was negatively correlated with that of LncRNA-Malat1 and COX-2. Knockdown of LncRNA-Malat1 inhibited the expression of COX-2 by up-regulating miR-211-5p.

CONCLUSION

Higher expression of LncRNA-Malat1 was involved in neuronal injury, LncRNA-Malat1 knockdown may reduce inflammation and apoptosis by modulating miR-211-5p, which provided a new therapeutic strategy for clinical stroke intervention targets.

MicroRNAs as Biomarkers of Charcot-Marie-Tooth Disease Type 1A

OBJECTIVE

To determine whether microRNAs (miRs) are elevated in the plasma of individuals with the inherited peripheral neuropathy Charcot-Marie-Tooth disease type 1A (CMT1A), miR profiling was employed to compare control and CMT1A plasma.

METHODS

We performed a screen of CMT1A and control plasma samples to identify miRs that are elevated in CMT1A using next-generation sequencing, followed by validation of selected miRs by quantitative PCR, and correlation with protein biomarkers and clinical data: Rasch-modified CMT Examination and Neuropathy Scores, ulnar compound muscle action potentials, and motor nerve conduction velocities.

RESULTS

After an initial pilot screen, a broader screen confirmed elevated levels of several muscle-associated miRNAs (miR1, -133a, -133b, and -206, known as myomiRs) along with a set of miRs that are highly expressed in Schwann cells of peripheral nerve. Comparison to other candidate biomarkers for CMT1A (e.g., neurofilament light) measured on the same sample set shows a comparable elevation of several miRs (e.g., miR133a, -206, -223) and ability to discriminate cases from controls. Neurofilament light levels were most highly correlated with miR133a. In addition, the putative Schwann cell miRs (e.g., miR223, -199a, -328, -409, -431) correlate with the recently described transmembrane protease serine 5 (TMPRSS5) protein biomarker that is most highly expressed in Schwann cells and also elevated in CMT1A plasma.

CONCLUSIONS

These studies identify a set of miRs that are candidate biomarkers for clinical trials in CMT1A. Some of the miRs may reflect Schwann cell processes that underlie the pathogenesis of the disease.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that a set of plasma miRs are elevated in patients with CMT1A.

miR-30c-5p acts as a therapeutic target for ameliorating myocardial ischemia-reperfusion injury

Coronary heart disease (CHD) is one of the most vital reasons for death and disability all over the world. miRNA, as a plasma index, is quite valuable for disease screening and prognosis prediction in CHD. Mining the molecular mechanism behind miRNA is also helpful for us to find molecular therapeutic strategies. In this research, we found that the expression of plasma miR-30c-5p in CHD patients was obviously lower than that in the control group (CG), which had a high differential value for CHD. We also discovered that miR-30c-5p was obviously correlated with clinical characteristics of CHD patients such as age, NYHA grade, smoking history, hypertension, hyperlipidemia, etc. In prognosis analysis, the miR-30c-5p expression in patients with poor prognosis was dramatically lower than that in those with good one, and the AUC for predicting poor prognosis of CHD was not lower than 0.850. In addition, we also induced myocardial ischemia/reperfusion (I/R) injury model of H9C2 cells through hypoxia/reoxygenation, and found that H9C2 cells also had abnormally down-regulated miR-30c-5p and up-regulated BCL2-like 11 (BCL2L11). Up-regulating miR-30c-5p or down-regulating BCL2L11 were helpful to improve proliferation and apoptosis of I/R injury model. Mechanically, BCL2L11 was also negatively regulated by miR-30c-5p, and up-regulating the former could cancel the in vitro protective effect of up-regulating the latter on H9C2 cell I/R injury model. In vivo research, up-regulating miR-30c-5p or down-regulating BCL2L11 can improve myocardial injury, histopathological changes and apoptosis in rat I/R model.

Difference in serum miRNA expression between immunoglobulin-sensitive and -insensitive incomplete Kawasaki disease patients

The present study aimed to investigate the expression of microRNAs (miRNAs/miRs) and inflammatory factors in patients with immunoglobulin-sensitive and IVIG-insensitive incomplete Kawasaki disease (KD). One hundred and eighty-five patients with incomplete KD were included as the study group (KD group), and 182 patients with respiratory infection as the control group. Neutrophil to lymphocyte ratio (NLR), C-reactive protein (CRP) levels, alanine aminotransferase (ALT), aspartate aminotransferase (AST), white blood cell count (WBC), hemoglobin level (Hb), platelet count (PLT) and T cell subsets (CD3⁺, CD3⁺ CD4⁺) were compared. Patients in the KD group received aspirin (30 mg/kg orally daily) and gamma globulin (IVIG, 1 g/kg intravenously daily). According to the sensitivity to IVIG, patients were divided into IVIG-sensitive group and IVIG-insensitive KD group. The relative expression levels of miRNA-21, miRNA-145, miRNA-155 and miRNA-199b-5p in the serum were detected by RT-qPCR. Serum TNF-α, IL-6 and IL-1β levels were assessed using ELISA. Before treatment, the neutrophil to lymphocyte ratio (NLR), levels C-reactive protein, and leukocytes in the KD group were significantly higher compared with the control group (P<0.05). After medical intervention, the relative expression of miRNA-21, miRNA-145 and miRNA-155 in the serum of patients in IVIG-sensitive and IVIG-insensitive KD groups were increased when compared with these levels in the control group (P<0.05). Meanwhile, the relative expression of miRNA-199b-5p was decreased (P<0.05). Compared with the IVIG-sensitive KD group, the relative expression levels of miRNA-145 and miRNA-155 were increased in the serum of patients in the IVIG-insensitive KD group (P<0.05). Compared with the control group, the levels of TNF-α, IL-6 and IL-1β were increased in the serum of patients in the IVIG-sensitive and IVIG-insensitive KD groups (P<0.05). Compared with the IVIG-sensitive KD group, the serum levels of TNF-α and IL-6 were increased in patients of the IVIG-insensitive KD group (P<0.05). Except for NLR and CRP, there were differences in the expression of peripheral blood miRNA-145, miRNA-155 and serum TNF-α and IL-6 in patients with immunoglobulin-sensitive and -insensitive incomplete KD.

MiR-223-3p and miR-122-5p as circulating biomarkers for plaque instability

BACKGROUND

In this study, we discovered and validated candidate microRNA (miRNA) biomarkers for coronary artery disease (CAD).

METHOD

Candidate tissue-derived miRNAs from atherosclerotic plaque material in patients with stable coronary artery disease (SCAD) (n=14) and unstable coronary artery disease (UCAD) (n=25) were discovered by qPCR-based arrays. We validated differentially expressed miRNAs, along with seven promising CAD-associated miRNAs from the literature, in the serum of two large cohorts (n=395 and n=1000) of patients with SCAD and UCAD and subclinical atherosclerosis (SubA) and controls, respectively.

RESULT

From plaque materials (discovery phase), miR-125b-5p and miR-193b-3p were most upregulated in SCAD, whereas miR-223-3p and miR-142-3p were most upregulated in patients with UCAD. Subsequent validation in serum from patients with UCAD, SCAD, SubA and controls demonstrated significant upregulation of miR-223-3p, miR-133a-3p, miR-146-3p and miR-155-5p. The ischaemia-related miR-499-5p was also highly upregulated in patients with UCAD compared with the other groups (SCAD OR 20.63 (95% CI 11.16 to 38.15), SubA OR 96.10 (95% CI 40.13 to 230.14) and controls OR 15.73 (95% CI 7.80 to 31.72)). However, no significant difference in miR-499-5p expression was observed across SCAD, SubA and controls. MiR-122-5p was the only miRNA to be significantly upregulated in the serum of both patients with UCAD and SCAD.

CONCLUSION

In conclusion, miR-122-5p and miR-223-3p might be markers of plaque instability.

Long non-coding RNA expression profiles in peripheral blood mononuclear cells of patients with coronary artery disease

Background

Coronary artery disease (CAD) is a leading cause of death and often presents as a complex systemic disease. The aim of the presents study was to determine the expression profiles of long non-coding RNAs (lncRNAs) in peripheral blood mononuclear cells (PBMC) of CAD patients and controls.

Methods

The lncRNA expression profiling of PBMC obtained from 40 CAD patients and 10 non-obstructive coronary atherosclerosis (NOCA) subjects were analyzed using the Illumina Hiseq 4000 sequencer. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the differentially expressed lncRNAs. Gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of mRNA were conducted to predict biologic functions.

Results

Our results indicated that lncRNAs were differentially expressed; 83 were upregulated lncRNAs and 114 were downregulated lncRNAs (P<0.05). A horizontal comparison of lncRNA expression indicated that the change in the expression profile of 48 lncRNAs was consistent with the degree of CAD. Six lncRNAs were validated using qRT-PCR, confirming the accuracy of the RNA sequencing analysis. GO analysis indicated that these dysregulated lncRNA transcripts were related to chromatin organization, cell and cell part, and protein heterodimerization activity. Pathway analysis indicated that these differentially expressed genes mainly included viral carcinogenesis, systemic lupus erythematosus and alcoholism.

Conclusions

Our preliminary findings indicate that lncRNAs could be used as potential biomarkers of subclinical cardiac abnormalities in the PBMC of CAD patients. However, further studies are needed to verify our findings and hypothesis.

lncRNA-NRF is a Potential Biomarker of Heart Failure After Acute Myocardial Infarction

Long non-coding RNAs (lncRNAs) are a new focus in cardiovascular diseases. The necrosis-related factor (NRF) is a newly discovered lncRNA, which is increased in myocardial injury. We investigated the role of lncRNA-NRF in heart failure (HF) after acute myocardial infarction (AMI) to find a biomarker for early HF detection. This was a cross-sectional study of 76 AMI patients with HF and 58 AMI patients without HF. lncRNA-NRF was shown to be increased in AMI patients with HF compared with AMI patients without HF and had predictive value for diagnosis of HF. It had a high diagnostic value for HF (AUC, 0.975), while the AUC for N-terminal pro-brain natriuretic peptide was 0.720. Our findings suggest that lncRNA-NRF may represent a marker of risk for development of HF post-AMI.

Noncoding RNAs implication in cardiovascular diseases in the COVID-19 era

COronaVIrus Disease 19 (COVID-19) is caused by the infection of the Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2). Although the main clinical manifestations of COVID-19 are respiratory, many patients also display acute myocardial injury and chronic damage to the cardiovascular system. Understanding both direct and indirect damage caused to the heart and the vascular system by SARS-CoV-2 infection is necessary to identify optimal clinical care strategies. The homeostasis of the cardiovascular system requires a tight regulation of the gene expression, which is controlled by multiple types of RNA molecules, including RNA encoding proteins (messenger RNAs) (mRNAs) and those lacking protein-coding potential, the noncoding-RNAs. In the last few years, dysregulation of noncoding-RNAs has emerged as a crucial component in the pathophysiology of virtually all cardiovascular diseases. Here we will discuss the potential role of noncoding RNAs in COVID-19 disease mechanisms and their possible use as biomarkers of clinical use.

VAV3 rs7528153 and VAV3-AS1 rs1185222 polymorphisms are associated with an increased risk of developing hypertension

The aetiology of essential hypertension is complex and involves both environmental and genetic factors. Approximately 30% of the inter-individual variability in blood pressure is genetically determined. It has been shown that numerous vasoconstrictors stimulate RhoA in local populations of vascular SMCs that, in turn, promote localised constriction of arterial blood vessels and elevations in blood pressure. The VAV3 gene encodes for VAV3 protein, a Rho GEF factor. VAV3-AS1 gene, a lncRNA, may regulate VAV3 expression. We performed an observational prospective case-control study, including patients attending in the Vascular Risk Unit from the University Hospital Salamanca for 6 months. A replication study was performed with data from The Kaiser Permanent database of the University of California. The results suggest that T allele of the VAV3 rs7528153 and G allele of the VAV3-AS1 rs11185222 polymorphisms are associated with an increased risk of developing hypertension. We hypothesise that these polymorphisms could modify blood pressure, likely through a modification in the Rho/Rac pathway. Our results suggest that those polymorphisms could be useful genetic markers of susceptibility to suffering hypertension.

The roles of long noncoding RNAs in myocardial pathophysiology

Long noncoding RNAs (lncRNAs), more than 200 nt in length, are functional molecules found in various species. These lncRNAs play a vital role in cell proliferation, differentiation, and degeneration and are also involved in pathophysiological processes of cancer and neurodegenerative, autoimmune, and cardiovascular diseases (CVDs). In recent years, emerging challenges for intervention studies on ischemic heart diseases have received much attention. LncRNAs have a key function in the alleviation of myocardial infarction (MI) injury and myocardial ischemia–reperfusion injury. During cardiac hypertrophy (CH) and fibrosis, cardiac cells undergo structural changes and become dysfunctional due to the effects of neurohormonal factors. LncRNAs may serve as important therapeutic targets that promote cardiac remodeling and then retard the development of heart failure (HF). In addition, studies on the roles and mechanisms of action of lncRNAs participating in cardiac pathophysiology via other factors have become the focus of research worldwide. Here, we review the current knowledge on various lncRNAs and their functions in cardiac biology, particularly concentrating on ischemic heart disease, CH, and cardiac fibrosis. We next discuss the predictive value of lncRNAs as diagnostic biomarkers of CVDs.

Association of long-chain non-coding RNA MHRT gene single nucleotide polymorphism with risk and prognosis of chronic heart failure

Long-chain non-coding RNA (lncRNA) Myosin Heavy Chain Associated RNA Transcripts (MHRT) are newly identified cardioprotective lncRNAs. In this study, we investigated the association of MHRT gene single nucleotide polymorphisms with risk and prognosis of chronic heart failure (CHF).Sanger sequencing was performed to detect the genotypes of rs3729830, rs7140721, rs76614781, rs3729829, rs3729828, rs3729825, and rs3729822 loci in the non-coding region of the MHRT gene from 240 patients with CHF and 240 control subjects. After 3 years of follow-up, progression-free survival was recorded in patients with CHF.The risk of CHF in subjects carrying A allele of the MHRT gene rs7140721 locus was 1.43 times higher than that of C allele carriers (95% CI: 1.23-1.62, P < .001). The risk of CHF in subjects carrying A allele of the rs3729829 locus was 1.41 times higher than that of G allele carriers (95% CI: 1.20-1.61, P < .01). The risk of CHF in the carriers of T allele of the rs3729825 locus was 1.89 times higher than that of C allele carriers (adjusted OR = 1.89, 95% CI: 1.66-2.04, P < .01). Further, the level of lncRNA MHRT in the plasma of subjects carrying CA/AA genotype of the rs7140721 locus was significantly higher than that of subjects carrying the CC genotype. The level of lncRNA MHRT in the plasma of subjects carrying GA/AA genotype of the rs3729829 locus was significantly higher than that of subjects carrying the GG genotype. In addition, the level of lncRNA MHRT in subjects with CT/TT genotype of the rs3729825 locus carriers was significantly higher than that in subjects with the CC genotype (P < .05). In addition, significant differences in the mortality of patients with CHF were observed between different genotypes of rs7140721, rs3729829, and rs3729825 loci (P < .001).The single nucleotide polymorphisms of MHRT gene rs7140721, rs3729829, and rs3729825 loci were associated with the risk of CHF and prognosis.

Non-coding RNAs and Ischemic Cardiovascular Diseases

The Ischemic Heart Disease (IHD) is considered a clinical condition characterized by myocardial ischemia causing an imbalance between myocardial blood supply and demand, leading to morbidity and mortality across the worldwide. Prompt diagnostic and prognostic represents key factors for the treatment and reduction of the mortality rate. Therefore, one of the newest frontiers in cardiovascular research is related to non-coding RNAs (ncRNAs), which prompted a huge interest in exploring ncRNAs candidates for utilization as potential therapeutic targets for diagnostic and prognostic and/or biomarkers in IHD. However, there are undoubtedly many more functional ncRNAs yet to be discovered and characterized. Here we will discuss our current knowledge and we will provide insight on the roles and effects elicited by some ncRNAs related to IHD.

Genetic associations and regulation of expression indicate an independent role for 14q32 snoRNAs in human cardiovascular disease

AIMS

We have shown that 14q32 microRNAs are highly involved in vascular remodelling and cardiovascular disease. However, the 14q32 locus also encodes 41 'orphan' small nucleolar RNAs (snoRNAs). We aimed to gather evidence for an independent role for 14q32 snoRNAs in human cardiovascular disease.

METHODS AND RESULTS

We performed a lookup of the 14q32 region within the dataset of a genome wide association scan in 5244 participants of the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER). Single nucleotide polymorphisms (SNPs) in the snoRNA-cluster were significantly associated with heart failure. These snoRNA-cluster SNPs were not linked to SNPs in the microRNA-cluster or in MEG3, indicating that snoRNAs modify the risk of cardiovascular disease independently. We looked at expression of 14q32 snoRNAs throughout the human cardio-vasculature. Expression profiles of the 14q32 snoRNAs appeared highly vessel specific. When we compared expression levels of 14q32 snoRNAs in human vena saphena magna (VSM) with those in failed VSM-coronary bypasses, we found that 14q32 snoRNAs were up-regulated. SNORD113.2, which showed a 17-fold up-regulation in failed bypasses, was also up-regulated two-fold in plasma samples drawn from patients with ST-elevation myocardial infarction directly after hospitalization compared with 30 days after start of treatment. However, fitting with the genomic associations, 14q32 snoRNA expression was highest in failing human hearts. In vitro studies show that the 14q32 snoRNAs bind predominantly to methyl-transferase Fibrillarin, indicating that they act through canonical mechanisms, but on non-canonical RNA targets. The canonical C/D-box snoRNA seed sequences were highly conserved between humans and mice.

CONCLUSION

14q32 snoRNAs appear to play an independent role in cardiovascular pathology. 14q32 snoRNAs are specifically regulated throughout the human vasculature and their expression is up-regulated during cardiovascular disease. Our data demonstrate that snoRNAs merit increased effort and attention in future basic and clinical cardiovascular research.

Combining Bioinformatics Techniques to Study Diabetes Biomarkers and Related Molecular Mechanisms

Objective

To explore the mechanism of plasma circulating miRNA-126 and miRNA-28-3p in diabetes mellitus (DM) patients, and to identify the related bioinformatics analysis.

Methods

Randomly selected 120 DM patients as the observation group and 120 non- DM patients as the control group. The plasma circulating miRNA-126 and miRNA-28-3p were analyzed by qRT-PCR, and their target genes, biological information, related lncRNA and circRNA were predicted.

Results

The circulating miRNA-126 (0.1162 ± 0.0236 vs. 0.0018 ± 0.0862) and miRNA-28-3p (0.1378 ± 0.0268 vs. 0.0006 ± 0.0167) levels in the observation group were significantly higher than those in the control group, and differences were statistically significant (P < 0.01). The Pearson correlation coefficient of miRNA-126 and miRNA- 28-3p was 0.4337 (P < 0.01). ROC curve analysis of miRNA-126 and miRNA-28-3p showed that the differences of the area under curve were statistically significant between the two groups (P < 0.01). Bioinformatics prediction showed that miRNA-126 and miRNA-28-3p may be involved in regulation of the insulin signaling pathway, insulin receptor signaling pathway, insulin/insulin growth factor signaling pathway, mitogen-activated protein kinase (MAPK) signaling pathway and angiogenesis. Moreover, it may be associated with a variety of lncRNA and cir-cRNA.

Conclusion

Circulating miRNA-126 and miRNA-28-3p can be a potential biomarker of DM and it may play an important role in the DM by regulating insulin or insulin growth factor related signaling pathways.

A Roadmap for Fixing the Heart: RNA Regulatory Networks in Cardiac Disease

With the continuous development of RNA biology and massive genome-wide transcriptome analysis, more and more RNA molecules and their functions have been explored in the last decade. Increasing evidence has demonstrated that RNA-related regulatory networks play an important role in a variety of human diseases, including cardiovascular diseases. In this review, we focus on RNA regulatory networks in heart disease, most of which are devastating conditions with no known cure. We systemically summarize recent discoveries of important new components of RNA regulatory networks, including microRNAs, long non-coding RNAs, and circular RNAs, as well as multiple regulators that affect the activity of these networks in cardiac physiology and pathology. In addition, this review covers emerging micropeptides, which represent short open reading frames (sORFs) in long non-coding RNA transcripts that may modulate cardiac physiology. Based on the current knowledge of RNA regulatory networks, we think that ongoing discoveries will not only provide us a better understanding of the molecular mechanisms that underlie heart disease, but will also identify novel biomarkers and therapeutic targets for the diagnosis and treatment of cardiac disease.

Noncoding RNAs versus Protein Biomarkers in Cardiovascular Disease

The development of more sensitive protein biomarker assays results in continuous improvements in detectability, extending the range of clinical applications to the detection of subclinical cardiovascular disease (CVD). However, these efforts have not yet led to improvements in risk assessment compared with existing risk scores. Noncoding RNAs (ncRNAs) have been assessed as biomarkers, and miRNAs have attracted most attention. More recently, other ncRNA classes have been identified, including long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs). Here, we compare emerging ncRNA biomarkers in the cardiovascular field with protein biomarkers for their potential in clinical application, focusing on myocardial injury.

Computational models for lncRNA function prediction and functional similarity calculation

From transcriptional noise to dark matter of biology, the rapidly changing view of long non-coding RNA (lncRNA) leads to deep understanding of human complex diseases induced by abnormal expression of lncRNAs. There is urgent need to discern potential functional roles of lncRNAs for further study of pathology, diagnosis, therapy, prognosis, prevention of human complex disease and disease biomarker detection at lncRNA level. Computational models are anticipated to be an effective way to combine current related databases for predicting most potential lncRNA functions and calculating lncRNA functional similarity on the large scale. In this review, we firstly illustrated the biological function of lncRNAs from five biological processes and briefly depicted the relationship between mutations or dysfunctions of lncRNAs and human complex diseases involving cancers, nervous system disorders and others. Then, 17 publicly available lncRNA function-related databases containing four types of functional information content were introduced. Based on these databases, dozens of developed computational models are emerging to help characterize the functional roles of lncRNAs. We therefore systematically described and classified both 16 lncRNA function prediction models and 9 lncRNA functional similarity calculation models into 8 types for highlighting their core algorithm and process. Finally, we concluded with discussions about the advantages and limitations of these computational models and future directions of lncRNA function prediction and functional similarity calculation. We believe that constructing systematic functional annotation systems is essential to strengthen the prediction accuracy of computational models, which will accelerate the identification process of novel lncRNA functions in the future.

Long noncoding RNAs in key cellular processes involved in aortic aneurysms

Aortic aneurysm (AA) is a complex and dangerous vascular disease, featuring progressive and irreversible vessel dilatation. AA is typically detected either by screening, or identified incidentally through imaging studies. To date, no effective pharmacological therapies have been identified for clinical AA management, and either endovascular repair or open surgery remains the only option capable of preventing aneurysm rupture. In recent years, multiple research groups have endeavored to both identify noncoding RNAs and to clarify their function in vascular diseases, including aneurysmal pathologies. Notably, the molecular roles of noncoding RNAs in AA development appear to vary significantly between thoracic aortic aneurysms (TAAs) and abdominal aortic aneurysms (AAAs). Some microRNAs (miRNA - a non-coding RNA subspecies) appear to contribute to AA pathophysiology, with some showing major potential for use as biomarkers or as therapeutic targets. Studies of long noncoding RNAs (lncRNAs) are more limited, and their specific contributions to disease development and progression largely remain unexplored. This review aims to summarize and discuss the most current data on lncRNAs and their mediation of AA pathophysiology.

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This current review covers studies that have identified long non-coding RNAs in aortic aneurysm development and progression.

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We separately discuss transcripts and mechanisms of importance to thoracic as well as abdominal aortic aneurysms.

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Functional data on lncRNAs being identified are highlighted.

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Some have been studied in human as well as experimental models of the disease pathology.

Improving the therapeutic efficiency of noncoding RNAs in cancers using targeted drug delivery systems

The delivery of noncoding (nc)RNA to target cancer stem cells and metastatic tumors has shown many positive outcomes, resulting in improved and more efficient treatment strategies. The success of therapeutic RNA depends solely on passing cellular barriers to reach the target site, where it binds to the mRNA of the interest. By 2018, 20 clinical trials had been initiated, most focusing on cancer and diabetes, with some progressing to Phase II clinical trials testing the safety and efficacy of small interfering (si)RNA. Many challenges limit RNA interference (RNAi) and miRNA usage in vivo; therefore, various approaches have been developed to promote ncRNA efficiency and stability. In this review, we focus on targeting the tumor microenvironment (TME) via the modification of delivery systems utilizing nanotechnology-based delivery approaches.

Let-7f: A New Potential Circulating Biomarker Identified by miRNA Profiling of Cells Isolated from Human Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a progressive vascular disease responsible for 1–4% of the deaths in elderly men. This study aimed to characterize specific microRNA (miRNA) expression in aneurysmal smooth muscle cells (SMCs) and macrophages in order to identify circulating miRNAs associated with AAA. We screened 850 miRNAs in aneurysmal SMCs, M1 and M2 macrophages, and in control SMCs isolated by micro-dissection from aortic biopsies using microarray analysis. In all, 92 miRNAs were detected and 10 miRNAs were selected for validation by qRT-PCR in isolated cells (n = 5), whole control and aneurysmal aorta biopsies (n = 13), and plasma from patients (n = 24) undergoing AAA (over 50 mm) repair matched to patients (n = 18) with peripheral arterial disease (PAD) with atherosclerosis but not AAA. Seven miRNAs were modulated similarly in all aneurysmal cells. The Let-7f was downregulated in aneurysmal cells compared to control SMCs with a significant lower expression in M1 compared to M2 macrophages (0.1 fold, p = 0.03), correlated with a significant downregulation in whole aneurysmal aorta compared to control aorta (0.2 fold, p = 0.03). Significant levels of circulating let-7f (p = 0.048) were found in AAA patients compared to PAD patients with no significant correlation with aortic diameter (R² = 0.03). Our study underlines the utility of profiling isolated aneurysmal cells to identify other miRNAs for which the modulation of expression might be masked when the whole aorta is used. The results highlight let-7f as a new potential biomarker for AAA.

microRNA expression profile in Smooth Muscle Cells isolated from thoracic aortic aneurysm samples

PURPOSE

Thoracic aortic aneurysm (TAA) is a cardiovascular disease characterized by increased aortic diameter, treated with surgery and endovascular therapy in order to avoid aortic dissection or rupture. The mechanism of TAA formation has not been thoroughly studied and many factors have been proposed to drive its progression; however strong focus is attributed to modification of smooth muscle cells (SMCs). Latest research indicates, that microRNAs (miRNAs) may play a significant role in TAA development - these are multifunctional molecules consisting of 19-24 nucleotides involved in regulation of the gene expression level related to many biological processes, i.e. cardiovascular disease pathophysiology, immunity or inflammation.

MATERIALS AND METHODS

Primary SMCs were isolated from aortic scraps of TAA patients and age- and sex-matched healthy controls. Purity of isolated SMCs was determined by flow cytometry using specific markers: α-SMA, CALP, MHC and VIM. Real-time polymerase chain reaction (RT-PCR) was conducted for miRNA analysis.

RESULTS

We established an isolation protocol and investigated the miRNA expression level in SMCs isolated from aneurysmal and non-aneurysmal aortic samples. We identified that let-7 g (0.71-fold, p = 0.01), miR-130a (0.40-fold, p = 0.04), and miR-221 (0.49-fold, p = 0.05) significantly differed between TAA patients and healthy controls.

CONCLUSIONS

Further studies are required to improve our understanding of the pathophysiology underlying TAA, which may aid the development of novel, targeted therapies. The pivotal role of miRNAs in the cardiovascular system provides a new perspective on the pathophysiology of thoracic aortic aneurysms.

Circulating Exosomal miR-20b-5p Is Elevated in Type 2 Diabetes and Could Impair Insulin Action in Human Skeletal Muscle

miRNAs are noncoding RNAs representing an important class of gene expression modulators. Extracellular circulating miRNAs are both candidate biomarkers for disease pathogenesis and mediators of cell-to-cell communication. We examined the miRNA expression profile of total serum and serum-derived exosome-enriched extracellular vesicles in people with normal glucose tolerance or type 2 diabetes. In contrast to total serum miRNA, which did not reveal any differences in miRNA expression, we identified differentially abundant miRNAs in patients with type 2 diabetes using miRNA expression profiles of exosome RNA (exoRNA). To validate the role of these differentially abundant miRNAs on glucose metabolism, we transfected miR-20b-5p, a highly abundant exoRNA in patients with type 2 diabetes, into primary human skeletal muscle cells. miR-20b-5p overexpression increased basal glycogen synthesis in human skeletal muscle cells. We identified AKTIP and STAT3 as miR-20b-5p targets. miR-20b-5p overexpression reduced AKTIP abundance and insulin-stimulated glycogen accumulation. In conclusion, exosome-derived extracellular miR-20b-5p is a circulating biomarker associated with type 2 diabetes that plays an intracellular role in modulating insulin-stimulated glucose metabolism via AKT signaling.

Identification of lncRNA competitively regulated subpathways in myocardial infarction

The functions of long non-coding RNAs (lncRNAs) in myocardial infarction (MI) remain largely unknown. Thus, we used the subp athway-LINCE method to characterize the potential roles of lncRNAs in MI. Candidate lncRNA-mRNA interactions were obtained from miRNA-mRNA interactions and lncRNA-miRNA interactions. Then the lncRNA and mRNA co-expression relationship pairs (LncGenePairs) were screened from the lncRNAs and mRNA intersections, which were extracted through candidate lncRNA-mRNA interactions and sample gene expression profiles. The lncRNAs in LncGenePairs were embedded into pathway graphs as nodes through linking to their regulated mRNAs, which resulted in obtaining condition-specific lncRNA competitively regulated signal pathways (csLncRPs). Finally, the csLncRPs were calculated using lenient distance similarity to obtain the lncRNA competitively regulated subpathways. Based on the statistical significance of signal subpathways, lncRNA-mRNA networks were constructed, in which hub lncRNAs were selected. A total of 65 lncRNAs competitively regulated subpathways and 13 hub lncRNAs were obtained, which associated with a risk of MI. Identifying lncRNAs competitively regulated subpathways not only provides potential lncRNA biomarkers for MI, but also helps the understanding of pathogenesis of MI.

Biobanking: Objectives, Requirements, and Future Challenges-Experiences from the Munich Vascular Biobank

Collecting biological tissue samples in a biobank grants a unique opportunity to validate diagnostic and therapeutic strategies for translational and clinical research. In the present work, we provide our long-standing experience in establishing and maintaining a biobank of vascular tissue samples, including the evaluation of tissue quality, especially in formalin-fixed paraffin-embedded specimens (FFPE). Our Munich Vascular Biobank includes, thus far, vascular biomaterial from patients with high-grade carotid artery stenosis (n = 1567), peripheral arterial disease (n = 703), and abdominal aortic aneurysm (n = 481) from our Department of Vascular and Endovascular Surgery (January 2004–December 2018). Vascular tissue samples are continuously processed and characterized to assess tissue morphology, histological quality, cellular composition, inflammation, calcification, neovascularization, and the content of elastin and collagen fibers. Atherosclerotic plaques are further classified in accordance with the American Heart Association (AHA), and plaque stability is determined. In order to assess the quality of RNA from FFPE tissue samples over time (2009–2018), RNA integrity number (RIN) and the extent of RNA fragmentation were evaluated. Expression analysis was performed with two housekeeping genes—glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and beta-actin (ACTB)—using TaqMan-based quantitative reverse-transcription polymerase chain reaction (qRT)-PCR. FFPE biospecimens demonstrated unaltered RNA stability over time for up to 10 years. Furthermore, we provide a protocol for processing tissue samples in our Munich Vascular Biobank. In this work, we demonstrate that biobanking is an important tool not only for scientific research but also for clinical usage and personalized medicine.

Circulating Long Noncoding RNA LIPCAR Acts as a Novel Biomarker in Patients with ST-Segment Elevation Myocardial Infarction

BACKGROUND Long noncoding RNAs (lncRNAs) recently have been implicated in the pathological processes of cardiovascular diseases. In this study, LncRNADisease database and PubMed database were used to screen myocardial infraction (MI)-related lncRNAs and to investigate the diagnostic role of lncRNAs in ST-segment elevation myocardial infraction (STEMI). MATERIAL AND METHODS Forty-six patients with STEMI and 40 healthy controls were included in the study. Venous blood samples acquired at different time points and the expression levels of lncRNAs in plasma were measured by qRT-PCR. In addition, other blood samples were collected before and after percutaneous coronary intervention (PCI). Correlation analysis and receiver operating characteristic (ROC) curve were used to assess the diagnosis value of the markers. All included patients were followed up for 12±1 months. RESULTS Nine MI-related lncRNAs were selected from the database. The qRT-PCR results showed that the expression of hypoxia inducible factor 1A antisense RNA 2 (aHIF), member 1 opposite strand/antisense transcript 1 (KCNQ1OT1), and mitochondrial long noncoding RNA uc022bqs.1 (LIPCAR) were significantly increased in patients with STEMI compared to the control patients. The ROC curve showed that LIPCAR (AUC=0.782, 95% CI: 0.707-0.0.894) had better diagnostic accuracy. Moreover, correlation analysis indicated that LIPCAR were positively correlated with myocardial enzymes and negatively correlated with left ventricular ejection fraction. The level of LIPCAR in STEMI patients after PCI was lower (P<0.05). Multivariate regression analysis indicated that higher levels of LIPCAR were independent predictors of major adverse cardiovascular events in patients with STEMI (HR=5.93; 95% CI, 1.46-9.77; P=0.001). CONCLUSIONS Highly expressed LIPCAR in plasma may serve as a warning sign for the diagnosis of STEMI.

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.

Integration of "Omics" Strategies for Biomarkers Discovery and for the Elucidation of Molecular Mechanisms Underlying Brugada Syndrome

PURPOSE

The Brugada syndrome (BrS) is a severe inherited cardiac disorder. Given the high genetic and phenotypic heterogeneity of this disease, three different "omics" approaches are integrated in a synergic way to elucidate the molecular mechanisms underlying the pathophysiology of BrS as well as for identifying reliable diagnostic/prognostic markers.

EXPERIMENTAL DESIGN

The profiling of plasma Proteome and MiRNome is perfomed in a cohort of Brugada patients that were preliminary subjected to genomic analysis to assess a peculiar gene mutation profile.

RESULTS

The integrated analysis of "omics" data unveiled a cooperative activity of mutated genes, deregulated miRNAs and proteins in orchestrating transcriptional and post-translational events that are critical determining factors for the development of the Brugada pattern.

CONCLUSIONS AND CLINICAL RELEVANCE

This study provides the basis to shed light on the specific molecular fingerprints underlying BrS development and to gain further insights on the pathogenesis of this life-threatening cardiac disease.

Long Non-coding RNAs in Endothelial Biology

In recent years, the role of RNA has expanded to the extent that protein-coding RNAs are now the minority with a variety of non-coding RNAs (ncRNAs) now comprising the majority of RNAs in higher organisms. A major contributor to this shift in understanding is RNA sequencing (RNA-seq), which allows a largely unconstrained method for monitoring the status of RNA from whole organisms down to a single cell. This observational power presents both challenges and new opportunities, which require specialized bioinformatics tools to extract knowledge from the data and the ability to reuse data for multiple studies. In this review, we summarize the current status of long non-coding RNA (lncRNA) research in endothelial biology. Then, we will cover computational methods for identifying, annotating, and characterizing lncRNAs in the heart, especially endothelial cells.

Small nucleolar host gene 6 promotes esophageal squamous cell carcinoma cell proliferation and inhibits cell apoptosis

Esophageal cancer (ESCC) is one of the most common causes of cancer-associated mortality in China. The present investigation reveals that non-coding RNAs (ncRNAs), including long ncRNAs (lncRNAs), exert a significant effect on the initiation, development and metastasis of malignant tumors, including ESCC. However, to the best of our knowledge, the function of non-protein-coding genes that host small nucleolar RNAs has not been investigated in cancer, particularly in ESCC. The expression of small nucleolar host gene 6 (SNHG6) in 70 ESCC tissues and paired adjacent tissues was measured by reverse transcription quantitative polymerase chain reaction. Analysis demonstrated that SNHG6 expression was significantly increased in ESCC tissues, and associated with tumor size (P=0.040) and Tumor-Node-Metastasis stage (P<0.01). Knockdown of SNHG6 may inhibit proliferative and colony-forming abilities, and induce apoptosis, in ESCC cells. To the best of our knowledge, the data from the present study indicated for the first time that SNHG6 was upregulated in ESCC tissues and cell lines. This novel lncRNA may exert a marked effect on the generation and progression of ESCC, potentially providing a novel perspective on ESCC diagnosis and management.

Small sample sizes in high-throughput miRNA screens: A common pitfall for the identification of miRNA biomarkers

Since the discovery of microRNAs (miRNAs), circulating miRNAs have been proposed as biomarkers for disease. Consequently, many groups have tried to identify circulating miRNA biomarkers for various types of diseases including cardiovascular disease and cancer. However, the replicability of these experiments has been disappointingly low. In order to identify circulating miRNA candidate biomarkers, in general, first an unbiased high-throughput screen is performed in which a large number of miRNAs is detected and quantified in the circulation. Because these are costly experiments, many of such studies have been performed using a low number of study subjects (small sample size). Due to lack of power in small sample size experiments, true effects are often missed and many of the detected effects are wrong. Therefore, it is important to have a good estimate of the appropriate sample size for a miRNA high-throughput screen. In this review, we discuss the effects of small sample sizes in high-throughput screens for circulating miRNAs. Using data from a miRNA high-throughput experiment on isolated monocytes, we illustrate that the implementation of power calculations in a high-throughput miRNA discovery experiment will avoid unnecessarily large and expensive experiments, while still having enough power to be able to detect clinically important differences.

Increased plasma levels of lncRNA H19 and LIPCAR are associated with increased risk of coronary artery disease in a Chinese population

Recent studies in animal models and humans show that long non-coding RNAs (lncRNAs) are involved in the development of atherosclerosis, which contributes to the pathological foundation of coronary artery disease (CAD). LncRNAs in plasma and serum have been considered as promising novel biomarkers for diagnosis and prognosis of cardiovascular diseases, especially CAD. We here measured the circulating levels of 8 individual lncRNAs which are known to be relevant to atherosclerosis in the plasma samples from 300 patients with CAD and 180 control subjects by using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) methods. We found that the plasma level of H19 and long intergenic non-coding RNA predicting cardiac remodeling (LIPCAR) were significantly increased in patients with CAD. The area under the receiver operating characteristic curve was 0.631 for H19 and 0.722 for LIPCAR. Multivariate logistic regression analyses indicated that plasma H19 and LIPCAR were independent predictors for CAD, even after adjustment for traditional cardiovascular risk factors. Further studies identified that plasma levels of H19 and LIPCAR were also increased in CAD patients with heart failure compared to those with normal cardiac function. Taken together, our results suggest that increased plasma levels of H19 and LIPCAR are associated with increased risk of CAD and may be considered as novel biomarkers for CAD.

LncRNA ZFAS1 promotes cell migration and invasion of fibroblast-like synoviocytes by suppression of miR-27a in rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic and chronic inflammatory disease. Synoviocyte migration and invasion were found to be essential to the pathology of RA. Upregulation of long noncoding RNA ZFAS1 has been observed in cancers and promotes cell migration and invasion. To date, the functions and mechanisms of ZFAS1 in RA have not been revealed. In this study, we analyzed expression pattern of ZFAS1 in RA patients and found that ZFAS1 expression was increased in synovial tissue and fibroblast-like synoviocytes (FLS) from RA patients (RA-FLS) compared with that in healthy donors. Functional assays showed that silence of ZFAS1 suppressed RA-FLS migration and invasion, while overexpression of ZFAS1 showed the opposite effect. Further investigation demonstrated that ZFAS1 directly interacted with miR-27a and decreased miR-27a expression. ZFAS1 promotes RA-FLS migration and invasion in an miR-27a-dependent manner. Taken together, the present study provides the first evidence that ZFAS1 promotes cell migration and invasion through miR-27a in RA-FLS, suggesting that ZFAS1 may be an effective therapeutic target for RA patients.

Epigenetic Biomarkers and Cardiovascular Disease: Circulating MicroRNAs

MicroRNAs (miRNAs) are a class of small noncoding RNA (20-25 nucleotides) involved in gene regulation. In recent years, miRNAs have emerged as a key epigenetic mechanism in the development and physiology of the cardiovascular system. These molecular species regulate basic functions in virtually all cell types, and are therefore directly associated with the pathophysiology of a large number of cardiovascular diseases. Since their relatively recent discovery in extracellular fluids, miRNAs have been studied as potential biomarkers of disease. A wide array of studies have proposed miRNAs as circulating biomarkers of different cardiovascular pathologies (eg, myocardial infarction, coronary heart disease, and heart failure, among others), which may have superior physicochemical and biochemical properties than the conventional protein indicators currently used in clinical practice. In the present review, we provide a brief introduction to the field of miRNAs, paying special attention to their potential clinical application. This includes their possible role as new diagnostic or prognostic biomarkers in cardiovascular disease.

MicroRNAs in Coronary Heart Disease: Ready to Enter the Clinical Arena?

Coronary artery disease (CAD) and its complication remain the leading cause of mortality in industrialized countries despite great advances in terms of diagnosis, prognosis, and treatment options. MicroRNAs (miRNAs), small noncoding RNAs, act as posttranscriptional gene expression modulators and have been implicated as key regulators in several physiological and pathological processes linked to CAD. Circulating miRNAs have been evaluated as promising novel biomarkers of CAD, acute coronary syndromes, and acute myocardial infarction, with prognostic implications. Several challenges related to technical aspects, miRNAs normalization, drugs interaction, and quality reporting of statistical multivariable analysis of the miRNAs observational studies remain unresolved. MicroRNA-based therapies in cardiovascular diseases are not ready yet for human trials but definitely appealing. Through this review we will provide clinicians with a concise overview of the pros and cons of microRNAs.