MicroRNA-21 is a unique signature associated with coronary plaque instability in humans by regulating matrix metalloproteinase-9 via reversion-inducing cysteine-rich protein with Kazal motifs

Epidrugs in the clinical management of atherosclerosis: Mechanisms, challenges and promises

Atherosclerosis is a complex and multigenic pathology associated with significant epigenetic reprogramming. Traditional factors (age, sex, obesity, hyperglycaemia, dyslipidaemia, hypertension) and non-traditional factors (foetal indices, microbiome alteration, clonal hematopoiesis, air pollution, sleep disorders) induce endothelial dysfunction, resulting in reduced vascular tone and increased vascular permeability, inflammation and shear stress. These factors induce paracrine and autocrine interactions between several cell types, including vascular smooth muscle cells, endothelial cells, monocytes/macrophages, dendritic cells and T cells. Such cellular interactions lead to tissue-specific epigenetic reprogramming regulated by DNA methylation, histone modifications and microRNAs, which manifests in atherosclerosis. Our review outlines epigenetic signatures during atherosclerosis, which are viewed as potential clinical biomarkers that may be adopted as new therapeutic targets. Additionally, we emphasize epigenetic modifiers referred to as 'epidrugs' as potential therapeutic molecules to correct gene expression patterns and restore vascular homeostasis during atherosclerosis. Further, we suggest nanomedicine-based strategies involving the use of epidrugs, which may selectively target cells in the atherosclerotic microenvironment and reduce off-target effects.

Matrix metallopeptidase 9 contributes to the beginning of plaque and is a potential biomarker for the early identification of atherosclerosis in asymptomatic patients with diabetes

AIMS

To determine the roles of matrix metallopeptidase-9 (MMP9) on human coronary artery smooth muscle cells (HCASMCs) in vitro, early beginning of atherosclerosis in vivo in diabetic mice, and drug naïve patients with diabetes.

METHODS

Active human MMP9 (act-hMMP9) was added to HCASMCs and the expressions of MCP-1, ICAM-1, and VCAM-1 were measured. Act-hMMP9 (n=16) or placebo (n=15) was administered to diabetic KK.Cg-Ay/J (KK) mice. Carotid artery inflammation and atherosclerosis measurements were made at 2 and 10 weeks after treatment. An observational study of newly diagnosed drug naïve patients with type 2 diabetes mellitus (T2DM n=234) and healthy matched controls (n=41) was performed and patients had ultrasound of carotid arteries and some had coronary computed tomography angiogram for the assessment of atherosclerosis. Serum MMP9 was measured and its correlation with carotid artery or coronary artery plaques was determined.

RESULTS

In vitro, act-hMMP9 increased gene and protein expressions of MCP-1, ICAM-1, VCAM-1, and enhanced macrophage adhesion. Exogenous act-hMMP9 increased inflammation and initiated atherosclerosis in KK mice at 2 and 10 weeks: increased vessel wall thickness, lipid accumulation, and Galectin-3+ macrophage infiltration into the carotid arteries. In newly diagnosed T2DM patients, serum MMP9 correlated with carotid artery plaque size with a possible threshold cutoff point. In addition, serum MMP9 correlated with number of mixed plaques and grade of lumen stenosis in coronary arteries of patients with drug naïve T2DM.

CONCLUSION

MMP9 may contribute to the initiation of atherosclerosis and may be a potential biomarker for the early identification of atherosclerosis in patients with diabetes.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov, identifier NCT04424706.

MiR-21 Regulates Growth and Migration of Cervical Cancer Cells by RECK Signaling Pathway

Expression of miR-21 has been found to be altered in almost all types of cancers, and it has been classified as an oncogenic microRNA. In addition, the expression of tumor suppressor gene RECK is associated with miR-21 overexpression in high-grade cervical lesions. In the present study, we analyze the role of miR-21 in RECK gene regulation in cervical cancer cells. To identify the downstream cellular target genes of upstream miR-21, we silenced endogenous miR-21 expression using siRNAs. We analyzed the expression of miR-21 and RECK, as well as functional effects on cell proliferation and migration. We found that in cervical cancer cells, there was an inverse correlation between miR-21 expression and RECK mRNA and protein expression. SiRNAs to miR-21 increased luciferase reporter activity in construct plasmids containing the RECK-3'-UTR microRNA response elements MRE21-1, MRE21-2, and MRE21-3. The role of miR-21 in cell proliferation was also analyzed, and cancer cells transfected with siRNAs exhibited a markedly reduced cell proliferation and migration. Our findings indicate that miR-21 post-transcriptionally down-regulates the expression of RECK to promote cell proliferation and cell migration inhibition in cervical cancer cell survival. Therefore, miR-21 and RECK may be potential therapeutic targets in gene therapy for cervical cancer.

Emerging Roles of Lysophosphatidic Acid in Macrophages and Inflammatory Diseases

Lysophosphatidic acid (LPA) is a bioactive phospholipid that regulates physiological and pathological processes in numerous cell biological functions, including cell migration, apoptosis, and proliferation. Macrophages are found in most human tissues and have multiple physiological and pathological functions. There is growing evidence that LPA signaling plays a significant role in the physiological function of macrophages and accelerates the development of diseases caused by macrophage dysfunction and inflammation, such as inflammation-related diseases, cancer, atherosclerosis, and fibrosis. In this review, we summarize the roles of LPA in macrophages, analyze numerous macrophage- and inflammation-associated diseases triggered by LPA, and discuss LPA-targeting therapeutic strategies.

Inflammaging: mechanisms and role in the cardiac and vasculature

Aging triggers a wide range of cellular and molecular aberrations in the body, giving rise to inflammation and associated diseases. In particular, aging is associated with persistent low-grade inflammation even in absence of inflammatory stimuli, a phenomenon commonly referred to as 'inflammaging'. Accumulating evidence has revealed that inflammaging in vascular and cardiac tissues is associated with the emergence of pathological states such as atherosclerosis and hypertension. In this review we survey molecular and pathological mechanisms of inflammaging in vascular and cardiac aging to identify potential targets, natural therapeutic compounds, and other strategies to suppress inflammaging in the heart and vasculature, as well as in associated diseases such as atherosclerosis and hypertension.

Differential Expression of Peripheral Circulating MicroRNA-146a Between Patients with Atherosclerotic Vulnerable Plaque and Stable Plaque

Atherosclerotic plaque rupture and subsequent cardiovascular complications threaten the population's health worldwide. The polymorphism of miR-146a rs2910164 was significantly associated with the risk of vulnerable plaques. However, it remains unclear whether the circulating miR-146a is differentially expressed in stable and vulnerable plaques and thus, serves as a potential biomarker.This study aims to analyze the differential expression of circulating miR-146a between patients with stable and vulnerable plaques to explore the potential molecular mechanisms.Public databases were searched from their inception up to November 2022. A study reporting the specific circulating miR-146a levels between patients with stable and vulnerable plaques was included. The study quality was assessed using the modified genetic 8-stars Newcastle-Ottawa scale. The differential expression levels of miR-146a were evaluated using the standardized mean difference (SMD).Eight studies with 978 patients were included and analyzed. The results showed that miR-146a expression levels were significantly higher in the vulnerable plaque population than in the stable plaque population (SMD: 1.91; 95% confidence interval: 1.35, 2.47; P < 0.01). A similar statistical significance was found in subgroup analyses regarding sample source, disease type, and vulnerable plaque characteristics. Sensitivity analysis suggested the robustness of the results. Analysis of downstream genes suggested that miR-146a-targeted regulation of ACTN4, SARM1, and ULK2 may affect intraplaque hemorrhage.Patients with vulnerable plaque have higher circulating miR-146a levels than those with stable plaque. However, based on the limitations of this study, high-quality studies are still needed to confirm the results.

Circulating non-coding RNAs as biomarkers in coronary artery disease

Coronary artery disease (CAD) is a leading cause of mortality worldwide. Atherosclerosis involves an interplay of different pathological mechanisms, such as progressive inflammation, abnormal lipid metabolism, and oxidative stress, and as such represents the basic pathological phenomenon underlying CAD. Atherosclerotic plaque narrows the lumen of coronary arteries, creating an ischemic environment for the heart muscle, which finally leads to clinical complications, such as acute myocardial infarction. Currently, there are no biomarkers that could predict plaque stability or major adverse cardiovascular events (MACE). Numerous functional non-coding RNA (ncRNA) species influence basic cellular functions, and as such play a role in the development and progression of CAD. Of these ncRNAs, micro RNAs (miRNAs) and long non-coding RNAs (lncRNAs) are the most investigated. Considering that ncRNAs detected in extracellular fluids can originate from different cells, circulating ncRNAs are being intensively investigated as potential biomarkers in the diagnosis and prognosis of CAD. In the following paper, we provide current insights into potential molecular mechanisms by which miRNAs and lncRNAs contribute to the pathology of CAD and discuss their potential role as biomarkers in diagnosis and prognosis of disease.

Detection of Atherosclerosis by Small RNA-Sequencing Analysis of Extracellular Vesicle Enriched Serum Samples

Atherosclerosis can occur throughout the arterial vascular system and lead to various diseases. Early diagnosis of atherosclerotic processes and of individual disease patterns would be more likely to be successful if targeted therapies were available. For this, it is important to find reliable biomarkers that are easily accessible and with little inconvenience for patients. There are many cell culture, animal model or tissue studies that found biomarkers at the microRNA (miRNA) and mRNA level describing atherosclerotic processes. However, little is known about their potential as circulating and liquid biopsy markers in patients. In this study, we examined serum-derived miRNA - profiles from 129 patients and 28 volunteers to identify potential biomarkers. The patients had four different atherosclerotic manifestations: abdominal aneurysm (n = 35), coronary heart disease (n = 34), carotid artery stenosis (n = 24) and peripheral arterial disease (n = 36). The samples were processed with an extracellular vesicle enrichment protocol, total-RNA extraction and small RNA-sequencing were performed. A differential expression analysis was performed bioinformatically to find potentially regulated miRNA biomarkers. Resulting miRNA candidates served as a starting point for an overrepresentation analysis in which relevant target mRNAs were identified. The Gene Ontology database revealed relevant biological functions in relation to atherosclerotic processes. In patients, expression of specific miRNAs changed significantly compared to healthy volunteers; 27 differentially expressed miRNAs were identified. We were able to detect a group-specific miRNA fingerprint: miR-122-5p, miR-2110 and miR-483-5p for abdominal aortic aneurysm, miR-370-3p and miR-409-3p for coronary heart disease, miR-335-3p, miR-381-3p, miR493-5p and miR654-3p for carotid artery stenosis, miR-199a-5p, miR-215-5p, miR-3168, miR-582-3p and miR-769-5p for peripheral arterial disease. The results of the study show that some of the identified miRNAs have already been associated with atherosclerosis in previous studies. Overrepresentation analysis on this data detected biological processes that are clearly relevant for atherosclerosis, its development and progression showing the potential of these miRNAs as biomarker candidates. In a next step, the relevance of these findings on the mRNA level is to be investigated and substantiated.

Circulating Biomarkers Reflecting Destabilization Mechanisms of Coronary Artery Plaques: Are We Looking for the Impossible?

Despite significant strides to mitigate the complications of acute coronary syndrome (ACS), this clinical entity still represents a major global health burden. It has so far been well-established that most of the plaques leading to ACS are not a result of gradual narrowing of the vessel lumen, but rather a result of sudden disruption of vulnerable atherosclerotic plaques. As most of the developed imaging modalities for vulnerable plaque detection are invasive, multiple biomarkers were proposed to identify their presence. Owing to the pivotal role of lipids and inflammation in the pathophysiology of atherosclerosis, most of the biomarkers originated from one of those processes, whereas recent advancements in molecular sciences shed light on the use of microRNAs. Yet, at present there are no clinically implemented biomarkers or any other method for that matter that could non-invasively, yet reliably, diagnose the vulnerable plaque. Hence, in this review we summarized the available knowledge regarding the pathophysiology of plaque instability, the current evidence on potential biomarkers associated with plaque destabilization and finally, we discussed if search for biomarkers could one day bring us to non-invasive, cost-effective, yet valid way of diagnosing the vulnerable, rupture-prone coronary artery plaques.

The link among microbiota, epigenetics, and disease development

The microbiome is a community of various microorganisms that inhabit or live on the skin of humans/animals, sharing the body space with their hosts. It is a sort of complex ecosystem of trillions of commensals, symbiotic, and pathogenic microorganisms, including trillions of bacteria, archaea, protozoa, fungi, and viruses. The microbiota plays a role in the health and disease status of the host. Their number, species dominance, and viability are dynamic. Their long-term disturbance is usually accompanied by serious diseases such as metabolic disorders, cardiovascular diseases, or even cancer. While epigenetics is a term that refers to different stimuli that induce modifications in gene expression patterns without structural changes in the inherited DNA sequence, these changes can be reversible or even persist for several generations. Epigenetics can be described as cell memory that stores experience against internal and external factors. Results from multiple institutions have contributed to the role and close interaction of both microbiota and epigenetics in disease induction. Understanding the mechanisms of both players enables a better understanding of disease induction and development and also opens the horizon to revolutionary therapeutic approaches. The present review illustrates the roles of diet, microbiome, and epigenetics in the induction of several chronic diseases. In addition, it discusses the application of epigenetic data to develop diagnostic biomarkers and therapeutics and evaluate their safety for patients. Understanding the interaction among all these elements enables the development of innovative preventive/therapeutic approaches for disease control.

Reversion inducing cysteine rich protein with Kazal motifs and cardiovascular diseases: The RECKlessness of adverse remodeling

The Reversion Inducing Cysteine Rich Protein With Kazal Motifs (RECK) is a glycosylphosphatidylinositol (GPI) anchored membrane-bound regulator of matrix metalloproteinases (MMPs). It is expressed throughout the body and plays a role in extracellular matrix (ECM) homeostasis and inflammation. In initial studies, RECK expression was found to be downregulated in various invasive cancers and associated with poor prognostic outcome. Restoring RECK, however, has been shown to reverse the metastatic phenotype. Downregulation of RECK expression is also reported in non-malignant diseases, such as periodontal disease, renal fibrosis, and myocardial fibrosis. As such, RECK induction has therapeutic potential in several chronic diseases. Mechanistically, RECK negatively regulates various matrixins involved in cell migration, proliferation, and adverse remodeling by targeting the expression and/or activation of multiple MMPs, A Disintegrin And Metalloproteinase Domain-Containing Proteins (ADAMs), and A Disintegrin And Metalloproteinase With Thrombospondin Motifs (ADAMTS). Outside of its role in remodeling, RECK has also been reported to exert anti-inflammatory effects. In cardiac diseases, for example, it has been shown to counteract several downstream effectors of Angiotensin II (Ang-II) that play a role in adverse cardiac and vascular remodeling, such as Interleukin-6 (IL-6)/IL-6 receptor (IL-6R)/glycoprotein 130 (IL-6 signal transducer) signaling and Epidermal Growth Factor Receptor (EGFR) transactivation. This review article focuses on the current understanding of the multifunctional effects of RECK and how its downregulation may contribute to adverse cardiovascular remodeling.

lncRNA XIST regulates cell proliferation, migration and invasion via regulating miR-30b and RECK in nasopharyngeal carcinoma

Long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) plays an essential role in the development and progress of nasopharyngeal carcinoma (NPC). MicroRNA-30b (miR-30b) has been confirmed to play an inhibitory role in various types of cancer. The molecular mechanisms underlying the lncRNA XIST-mediated regulation of the metastasis of NPC cells by miR-30b is not clear. qPCR and western blot analysis were used to detect the expression of XIST, miR-30b, and reversion inducing cysteine rich protein with kazal motifs (RECK) in NPC tissues and cell lines. The detection of luciferase reporter gene confirmed the relationship between lncRNA XIST, miR-30b and RECK. CCK-8 and Transwell assays were performed in order to detect the proliferation, migration and invasion of the NPC cells. The results of qPCR and western blotting indicated that the expression levels of lncRNA XIST and RECK were higher in the NPC tissues and cell lines than that of the control group, while the expression of miR-30b was lower. Knockdown of lncRNA XIST significantly inhibited cell proliferation, migration and invasion in the NPC cell lines. In addition, lncRNA XIST was found to negatively regulate the expression of miR-30b, resulting in the upregulation of RECK. Overexpression of RECK was found to reverse the inhibitory effect of lncRNA XIST knockdown or miR-30b on NPC cell metastasis. Our results showed that cell migration and invasion were inhibited by knockdown of lncRNA XIST, suggesting that the lncRNA XIST/miR-30b/RECK axis is involved in the development of NPC.

Oxidative Stress in Ischemic Heart Disease

One of the novel interesting topics in the study of cardiovascular disease is the role of the oxidation system, since inflammation and oxidative stress are known to lead to cardiovascular diseases, their progression and complications. During decades of research, many complex interactions between agents of oxidative stress, oxidation, and antioxidant systems have been elucidated, and numerous important pathophysiological links to na number of disorders and diseases have been established. This review article will present the most relevant knowledge linking oxidative stress to vascular dysfunction and disease. The review will focus on the role of oxidative stress in endotheleial dysfunction, atherosclerosis, and other pathogenetic processes and mechanisms that contribute to the development of ischemic heart disease.

The role of miR-21 in nickel nanoparticle-induced MMP-2 and MMP-9 production in mouse primary monocytes: In vitro and in vivo studies

Exposure to metal nanoparticles causes both pulmonary and systemic effects. Nanoparticles can enter the circulation and act directly or indirectly on blood cells, such as monocytes. Monocytes/macrophages are among the first cells to home to inflammatory sites and play a key role in the immune response. Here we investigated the effects of nickel nanoparticles (Nano-Ni), partially [O]-passivated Nano-Ni (Nano-Ni-P), and carbon-coated Nano-Ni (Nano-Ni-C) on MMP-2 and MMP-9 production in mouse primary monocytes both in vitro and in vivo and explored the potential mechanisms involved. The dose- and time-response studies showed that exposure of primary monocytes from wild-type (WT) mice to 30 μg/mL of Nano-Ni for 24 h caused significant MMP-2 and MMP-9 production; therefore, these dose and time point were chosen for the following in vitro studies. Nano-Ni and Nano-Ni-P caused miR-21 upregulation, as well as MMP-2, MMP-9, TIMP-1 and TIMP-2 upregulation in monocytes from WT, but not miR-21 knock-out (KO), mice, indicating the important role of miR-21 in Nano-Ni-induced MMPs and TIMPs upregulation. However, Nano-Ni-C did not cause these effects, suggesting surface modification of Nano-Ni, such as carbon coating, alleviates Nano-Ni-induced miR-21 and MMPs upregulation. These results were further confirmed by in vivo studies by intratracheal instillation of nickel nanoparticles into WT and miR-21 KO mice. Finally, our results demonstrated that exposure of primary monocytes from WT mice to Nano-Ni and Nano-Ni-P caused downregulation of RECK, a direct miR-21 target, suggesting the involvement of miR-21/RECK pathway in Nano-Ni-induced MMP-2 and MMP-9 production.

Identification of hub genes in unstable atherosclerotic plaque by conjoint analysis of bioinformatics

AIMS

Unstable atherosclerotic plaque is the main pathological basis of acute coronary syndrome, which is the leading cause of death and disability worldwide. Therefore, we combined multiple bioinformatics tools to identify key genes related to unstable plaque.

MAIN METHODS

GSE94605 contained 7 plasma sample pools of 175 healthy and 6 sample pools of 150 unstable angina pectoris (UAP) patients, and detected with miRNA array while GSE60993 collected peripheral blood from 7 normal and 9 UAP, and detected with mRNA array. GSE120521 collected carotid plaques from 4 patients and dissected in stable and unstable regions, then detected with RNA-seq. Differentially expressed miRNAs (DEMs) and genes (DEGs) in UAP were re-analyzed. Gene Ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) and Protein-protein interaction (PPI) network were applied on top 10 up-regulated or down-regulated DEMs targets, and whole DEGs. MiRNAs-mRNAs network was constructed with these DEMs and DEGs, and the expression profile of genes within the network was finally validated in GSE120521.

KEY FINDINGS

Totally, 263 up-regulated and 201 down-regulated DEMs were identified in GSE94605, and 78 up-regulated and 29 down-regulated DEGs were identified in GSE60993. Subsequently, a miRNAs-mRNAs network was constructed with 6 up-regulated miRNAs targeted to 12 down-regulated genes, and 4 down-regulated miRNAs targeted to 8 up-regulated genes. Finally, MORF4L2, RAB3IL1 and MMP9 within the network were considered as hub genes in unstable plaque progression after being validated in GSE120521.

SIGNIFICANCE

These 3 genes may provide new targets for diagnosis and therapy of unstable atherosclerotic plaque.

Systemic Investigation of Promoter-wide Methylome and Genome Variations in Gout

Current knowledge of gout centers on hyperuricemia. Relatively little is known regarding the pathogenesis of gouty inflammation. To investigate the epigenetic background of gouty inflammation independent of hyperuricemia and its relationship to genetics, 69 gout patients and 1455 non-gout controls were included. Promoter-wide methylation was profiled with EPIC array. Whole-genome sequencing data were included for genetic and methylation quantitative trait loci (meQTL) analyses and causal inference tests. Identified loci were subjected to co-methylation analysis and functional localization with DNase hypersensitivity and histone marks analysis. An expression database was queried to clarify biologic functions of identified loci. A transcription factor dataset was integrated to identify transcription factors coordinating respective expression. In total, seven CpG loci involved in interleukin-1β production survived genetic/meQTL analyses, or causal inference tests. None had a significant relationship with various metabolic traits. Additional analysis suggested gouty inflammation, instead of hyperuricemia, provides the link between these CpG sites and gout. Six (PGGT1B, INSIG1, ANGPTL2, JNK1, UBAP1, and RAPTOR) were novel genes in the field of gout. One (CNTN5) was previously associated with gouty inflammation. Transcription factor mapping identified several potential transcription factors implicated in the link between differential methylation, interleukin-1β production, and gouty inflammation. In conclusion, this study revealed several novel genes specific to gouty inflammation and provided enhanced insight into the biological basis of gouty inflammation.

MicroRNAs: Novel Molecular Targets and Response Modulators of Statin Therapy

Cardiovascular disease (CVD) is a major cause of death globally. Addressing cardiovascular risk factors, particularly dyslipidemia, represents the most robust clinical strategy towards reducing the CVD burden. Statins inhibit 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase and represent the main therapeutic approach for lowering cholesterol and reducing plaque formation/rupture. The protective effects of statins extend beyond lowering cholesterol. MicroRNAs (miRNAs or miRs), small noncoding regulatory RNAs, likely mediate the positive pleiotropic effects of statins via modulation of lipid metabolism, enhancement of endothelial function, inhibition of inflammation, improvement of plaque stability, and immune regulation. miRNAs are implicated in statin-related interindividual variations in therapeutic response, directly via HMG-CoA reductase, or indirectly through targeting cytochrome P450 3A (CYP3A) functionality and proprotein convertase subtilisin/kexin type9 (PCSK9) biology.

Association of expression of ZNF606 gene from monocytes with the risk of coronary artery disease

AIM

Messenger RNAs (mRNAs) play an important role in the pathogenesis of coronary artery disease (CAD). We evaluated the association of selected increase in mRNAs from monocytes with the risk of CAD.

METHODS

Chip data (GSE9820) retrieved from Gene Expression Omnibus (GEO) was re-analyzed, and the selected candidate genes, meeting specific conditions, were up-regulated and verified for specific biomarkers of CAD within a prospective cohort study that recruited 194 individuals and subdivided into two groups: group Non-CAD (GN), n = 68 and group CAD (GC), n = 126. The patients in GC were further categorized into three sub-units according to the extent of coronary stenosis shown during coronary angiography, coded as single-vessel stenosis (GC1, n = 53), 2-vessel stenosis (GC2, n = 50), or ≥ 3-vessel stenosis (GC3, n = 23). All candidate mRNAs expressions were analyzed from patients' monocytes with quantitative PCR (q-PCR). Receiver-operating characteristic (ROC) curves and the area under the ROC curves (AUCs) were used to evaluate the mRNAs' feasibility for CAD prediction. AUCs ≥0.8 were accounted as highly specific association with CAD.

RESULTS

GBA2, CSTF3, ZNF606 and MPP5 were selected as mRNAs candidates from chip data reanalysis. GBA2 (P = .002) and ZNF606 (P < .001) expressions were significantly increased in GC. ZNF606 showed significant increase after adjusting the risk factors with logistic regression analysis (OR = 3.804, 95% CI: 1.923, 7.798, P < .001), and its expression level was positively correlated with age (β = 0.04 × 10^-3, P < .001). The AUCs (and 95% CI) of ZNF606 expression in GC2 and GC3 were ≥0.8.

CONCLUSION

These findings suggest that it is novel and specific for the association of ZNF606 gene expression from monocytes with the risk of CAD, especially in patients with multiple coronary artery stenosis.

Deciphering Non-coding RNAs in Cardiovascular Health and Disease

After being long considered as “junk” in the human genome, non-coding RNAs (ncRNAs) currently represent one of the newest frontiers in cardiovascular disease (CVD) since they have emerged in recent years as potential therapeutic targets. Different types of ncRNAs exist, including small ncRNAs that have fewer than 200 nucleotides, which are mostly known as microRNAs (miRNAs), and long ncRNAs that have more than 200 nucleotides. Recent discoveries on the role of ncRNAs in epigenetic and transcriptional regulation, atherosclerosis, myocardial ischemia/reperfusion (I/R) injury and infarction (MI), adverse cardiac remodeling and hypertrophy, insulin resistance, and diabetic cardiomyopathy prompted vast interest in exploring candidate ncRNAs for utilization as potential therapeutic targets and/or diagnostic/prognostic biomarkers in CVDs. This review will discuss our current knowledge concerning the roles of different types of ncRNAs in cardiovascular health and disease and provide some insight on the cardioprotective signaling pathways elicited by the non-coding genome. We will highlight important basic and clinical breakthroughs that support employing ncRNAs for treatment or early diagnosis of a variety of CVDs, and also depict the most relevant limitations that challenge this novel therapeutic approach.

The circulating non-coding RNA landscape for biomarker research: lessons and prospects from cardiovascular diseases

Pervasive transcription of the human genome is responsible for the production of a myriad of non-coding RNA molecules (ncRNAs) some of them with regulatory functions. The pivotal role of ncRNAs in cardiovascular biology has been unveiled in the last decade, starting from the characterization of the involvement of micro-RNAs in cardiovascular development and function, and followed by the use of circulating ncRNAs as biomarkers of cardiovascular diseases. The human non-coding secretome is composed by several RNA species that circulate in body fluids and could be used as biomarkers for diagnosis and outcome prediction. In cardiovascular diseases, secreted ncRNAs have been described as biomarkers of several conditions including myocardial infarction, cardiac failure, and atrial fibrillation. Among circulating ncRNAs, micro-RNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) have been proposed as biomarkers in different cardiovascular diseases. In comparison with standard biomarkers, the biochemical nature of ncRNAs offers better stability and flexible storage conditions of the samples, and increased sensitivity and specificity. In this review we describe the current trends and future prospects of the use of the ncRNA secretome components as biomarkers of cardiovascular diseases, including the opening questions related with their secretion mechanisms and regulatory actions.

Macrophage MicroRNAs as Therapeutic Targets for Atherosclerosis, Metabolic Syndrome, and Cancer

Macrophages play a crucial role in the innate immune system and contribute to a broad spectrum of pathologies in chronic inflammatory diseases. MicroRNAs (miRNAs) have been demonstrated to play important roles in macrophage functions by regulating macrophage polarization, lipid metabolism and so on. Thus, miRNAs represent promising diagnostic and therapeutic targets in immune disorders. In this review, we will summarize the role of miRNAs in atherosclerosis, metabolic syndrome, and cancer by modulating macrophage phenotypes, which has been supported by in vivo evidence.

MicroRNA regulation of extracellular matrix components in the process of atherosclerotic plaque destabilization

The process of atherosclerotic plaque destabilization, leading to myocardial infarction, is still not fully understood. The pathway - composed of structural and regulatory proteins of the extracellular matrix (ECM) such as collagen, elastin, small leucine-rich proteoglycans, metalloproteinases, cathepsins and serine proteases - is one potential way of atherosclerotic plaque destabilization. The expression of these proteins is controlled by different microRNA molecules. The goal of this paper is to summarize the current investigations and knowledge about ECM in the process of atherosclerotic plaque destabilization, giving special attention to epigenetic expression regulation by microRNA.

Role of microRNA in Development of Instability of Atherosclerotic Plaques

MicroRNAs are small noncoding single-stranded RNAs that regulate gene expression. Today, we see an increasing number of studies highlighting the important role of microRNAs in the development and progression of cardiovascular diseases caused by atherosclerotic lesions of arteries. We review the available scientific data on association of the expression of these biomolecules with instability of atherosclerotic plaques in animal models and humans. We made special emphasis on miR-21, -100, -127, -133, -143/145, -221/222, and -494 because they were analyzed in more than one study. We discuss the possibility of microRNAs using in the diagnosis and therapy of atherosclerosis and its complications.

The Involvement of miRNA in Carotid-Related Stroke

Cardiovascular disease is the leading cause of morbidity and mortality in developed countries. Stroke is associated with a marked disability burden and has a major economic impact; this is especially true for carotid artery stroke. Major advances in primary and secondary prevention during the last few decades have helped to tackle this public health problem. However, better knowledge of the physiopathology of stroke and its underlying genetic mechanisms is needed to improve diagnosis and therapy. miRNAs are an important, recently identified class of post-transcriptional regulators of gene expression and are known to be involved in cerebrovascular disease. These endogenous, small, noncoding RNAs may have applications as noninvasive biomarkers and therapeutic tools in practice. Here, we review the involvement of several miRNAs in cell-based and whole-animal models of stroke, with a focus on human miRNA profiling studies of carotid artery stroke. Lastly, we describe the miRNAs' potential role as a biomarker of stroke.

Distinct gene expression profiles associated with Notch ligands Delta-like 4 and Jagged1 in plaque material from peripheral artery disease patients: a pilot study

Background

The lack of early diagnosis, progression markers and effective pharmacological treatment has dramatic unfavourable effects on clinical outcomes in patients with peripheral artery disease (PAD). Addressing these issues will require dissecting the molecular mechanisms underlying this disease. We sought to characterize the Notch signaling and atherosclerosis relevant markers in lesions from femoral arteries of symptomatic PAD patients.

Methods

Plaque material from the common femoral, superficial femoral or popliteal arteries of 20 patients was removed by directional atherectomy. RNA was obtained from 9 out of 20 samples and analysed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR).

Results

We detected expression of Notch ligands Delta-like 4 (Dll4) and Jagged1 (Jag1), of Notch target genes Hes1, Hey1, Hey2, HeyL and of markers of plaque inflammation and stability such as vascular cell adhesion molecule 1 (VCAM1), smooth muscle 22 (SM22), cyclooxygenase 2 (COX2), Bcl2, CD68 and miRNAs 21-5p, 125a-5p, 126-5p,146-5p, 155-5p, 424-5p. We found an “inflamed plaque” gene expression profile characterized by high Dll4 associated to medium/high CD68, COX2, VCAM1, Hes1, miR126-5p, miR146a-5p, miR155-5p, miR424-5p and low Jag1, SM22, Bcl2, Hey2, HeyL, miR125a-5p (2/9 patients) and a “stable plaque” profile characterized by high Jag1 associated to medium/high Hey2, HeyL, SM22, Bcl2, miR125a and low Dll4, CD68, COX2, VCAM1, miR126-5p, miR146a-5p, miR155-5p, miR424-5p (3/9 patients). The remaining patients (4/9) showed a plaque profile with intermediate characteristics.

Conclusions

This study reveals the existence of a gene signature associated to Notch activation by specific ligands that could be predictive of PAD progression.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1199-3) contains supplementary material, which is available to authorized users.

Lysophosphatidic Acid Is Associated with Atherosclerotic Plaque Instability by Regulating NF-κB Dependent Matrix Metalloproteinase-9 Expression via LPA2 in Macrophages

Lysophosphatidic acid (LPA), one of the simplest phospholipid signaling molecules, participates in formation and disruption of atherosclerotic plaque. Matrix metalloproteinases (MMPs) contribute to atherosclerotic plaque rupture by involving in extracellular matrix (ECM) degradation and then thinning fibrous cap. Our previous study demonstrated that macrophage-derived MMP-9 was associated with coronary plaque instability, but the relationship between LPA and MMP-9 remains unclear. The present work therefore aimed at elucidating association between LPA and MMP-9 and the regulation mechanism of LPA on MMP-9 in macrophages. We found that plasma LPA and MMP-9 levels were correlated positively (r = 0.31, P < 0.05) and both elevated significantly in patients with acute myocardial infarct (AMI). Consistent with peripheral blood levels, histochemical staining indicated that autotaxin (ATX), LPA-producing ectoenzyme, and MMP-9 were expressed frequently in the necrotic core and fibrous cap of human unstable plaques, which might increase the instability of plaque. Experiments in vitro were done with THP-1-derived macrophages and showed that LPA enhanced the expression, secretion and activity of MMP-9 in a time- and dose-dependent manner. Induction of LPA on pro-MMP-9 and active-MMP-9 was confirmed in human peripheral blood monocyte-derived macrophages. PDTC, NF-κB inhibitor, but not inhibitor of AP-1 and PPARγ, effectively prevented LPA-induced MMP-9 expression and NF-κB p65 siRNA decreased MMP-9 transcription, confirming that LPA might induce MMP-9 elevation by activating NF-κB pathway. In addition, knockdown of LPA₂ attenuated LPA-induced MMP-9 expression and nucleus p65 levels. These findings revealed that LPA upregulated the expression of MMP-9 through activating NF-κB pathway in the LPA₂ dependent manner, hence blocking LPA receptors signaling may provide therapeutic strategy to target plaque destabilization.

microRNAs in cardiovascular disease - clinical application

microRNAs (miRNAs) are well-known, powerful regulators of gene expression, and their potential to serve as circulating biomarkers is widely accepted. In cardiovascular disease (CVD), numerous studies have suggested miRNAs as strong circulating biomarkers with high diagnostic as well as prognostic power. In coronary artery disease (CAD) and heart failure (HF), miRNAs have been suggested as reliable biomarkers matching up to established protein-based such as cardiac troponins (cT) or natriuretic peptides. Also, in other CVD entities, miRNAs were identified as surprisingly specific biomarkers - with great potential for clinical applicability, especially in those entities that lack specific protein-based biomarkers such as atrial fibrillation (AF) and acute pulmonary embolism (APE). In this regard, miRNA signatures, comprising a set of miRNAs, yield high sensitivity and specificity. Attempts to utilize miRNAs as therapeutic agents have led to promising results. In this article, we review the clinical applicability of circulating miRNAs in CVD. We are giving an overview of miRNAs as biomarkers in numerous CVD entities to depict the variety of their potential clinical deployment. We illustrate the function of miRNAs by means of single miRNA examples in CVD.

MicroRNAs in the Pathobiology and Therapy of Atherosclerosis

MicroRNAs are short noncoding RNAs, expressed in humans and involved in sequence-specific post-transcriptional regulation of gene expression. They have emerged as key players in a wide array of biological processes, and changes in their expression and/or function have been associated with plethora of human diseases. Atherosclerosis and its related clinical complications, such as myocardial infarction or stroke, represent the leading cause of death in the Western world. Accumulating experimental evidence has revealed a key role for microRNAs in regulating cellular and molecular processes related to atherosclerosis development, ranging from risk factors, to plaque initiation and progression, up to atherosclerotic plaque rupture. In this review, we focus on how microRNAs can influence atherosclerosis biology, as well as the potential clinical applications of microRNAs, which are being developed as targets as well as therapeutic agents for a growing industry hoping to harness the power of RNA-guided gene regulation to fight disease and infection.

Association of serum microRNA-21 levels with Visfatin, inflammation, and acute coronary syndromes

MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression. It seems that microRNA-21 (miR-21) and Visfatin, a novel adipocytokine, play roles in inflammation and atherosclerosis. The aim of this study was to investigate the association of miR-21 with Visfatin, inflammation, atherosclerosis and acute coronary syndrome (ACS). Based on coronary angiography and electrocardiogram (ECG), 53 patients with ACS and 52 patients with stable CAD were enrolled in this study. We assayed serum miR-21, Visfatin, and routine chemistries using quantitative reverse transcriptase polymerase chain reaction (QRT-PCR), enzyme-linked immunosorbent assay (ELISA) and automated analyzer, respectively. We used a regression analysis to describe the relationship between the variables. Serum miR-21 level in 2^-ΔCt value was significantly higher in ACS patients (10.52 ± 1.01-fold) than the stable CAD patients (4.4 ± 0.79-fold) (F = 4.59, p < 0.001). In addition, serum Visfatin was significantly higher in ACS patients (17.5 ± 0.61 ng/ml) than the stable CAD patients (12.7 ± 0.49 ng/ml) (F = 2.62, p < 0.001). Furthermore, the serum miR-21 level correlated positively with serum Visfatin level (r = 0.26, p = 0.008), hs-CRP (r = 0.29, p = 0.003), age (r = 0.21, p = 0.034) and negatively with HDL-cholesterol (r = -0.28, p = 0.004). We concluded that the increased serum miR-21 and Visfatin may be involved in the pathogenesis of ACS through promoting inflammation or may result from inflammatory responses to ACS. Furthermore, the potential role of miR-21 and Visfatin in plaque instability and inflammation warrants further investigations.

Differential Expression of MicroRNAs in Endarterectomy Specimens Taken from Patients with Asymptomatic and Symptomatic Carotid Plaques

Objective

Stroke and transient ischemic attacks are considered as clinical manifestations of atherosclerotic disease due to on-going vascular inflammation and finally atherothrombosis of the carotid arteries. MicroRNAs (miRNA/miR) are known to be involved in vascular inflammation and plaque destabilization. The aim of this study was to analyze the expression profile of selected miRNAs in endarterectomy specimen from carotid arteries that were taken from patients with asymptomatic and symptomatic atherosclerotic plaques.

Methods and Results

11 miRNAs were selected and their expression was analyzed using real-time RT-PCR. Therefore, samples were divided into three different groups. On the one hand we investigated the expression patterns from patients in asymptomatic (n = 14) and symptomatic (n = 10) plaques; on the other hand we took samples from normal configurated internal mammary arteries (n = 15). Out of these 11 targets we identified some miRNAs, which were up- or down-regulated in either one of the two groups. Interestingly, the expression of two miRNAs was significantly different between asymptomatic and symptomatic samples, namely miR-21 (P<0.01) and miR-143 (P<0.05).

Conclusion

In the present study, we identified miRNA subtypes which showed different expression in endarterectomy specimen from patients with asymptomatic and symptomatic plaques, suggesting that these miRNAs correlated with advanced vascular inflammation and plaque stability. They may represent new therapeutic targets for vascular proliferative diseases such as atherosclerosis.

The role of serum levels of microRNA-21 and matrix metalloproteinase-9 in patients with acute coronary syndrome

Acute coronary syndrome (ACS) is one of the leading causes of cardiovascular death. It seems that microRNA-21 and matrix metalloproteinase-9 implicated in the pathogenesis of cardiovascular diseases. The aim of this study was to investigate the role of circulating miR-21 and MMP-9 as biomarkers for ACS. Based on coronary angiography and electrocardiography results, 50 patients with ACS and 50 patients with stable coronary artery disease (stable CAD) were enrolled in this study. Samples were collected from patients and stored at -80 °C. Serum miR-21 gene expression was measured by quantitative real-time PCR method. Serum total MMP-9 was measured by enzyme-linked immunosorbent assay kit. Also, the activity of MMP-9 was measured by gelatin zymography. Patients with ACS had a significantly higher miR-21 level compared to the stable CAD ([Formula: see text] = 0.88 ± 0.06 and 0.31 ± 0.08 respectively, P < 0.001). At the same time, the serum levels and activity of MMP-9 were significantly higher in ACS patients compared to those with stable CAD (324.01 ± 17.57 and 204.6 ± 12.39 ng/mL, P < 0.001, and 2524.5 ± 131.3 and 1280.8 ± 19.6 units, P < 0.001, respectively). miR-21 expression levels were correlated positively with MMP-9, hs-CRP, and age and negatively with HDL-cholesterol (r = 0.33, P < 0.001, r = 0.22, P < 0.031, r = 0.26, P < 0.008, r = -0.32, P < 0.001, respectively). We concluded that increased serum expression of miR-21 and higher serum activity of MMP-9 may be useful indicators for ACS. However, we suggest further studies to be performed.

MicroRNA regulation of macrophages in human pathologies

Macrophages play a crucial role in the innate immune system and contribute to a broad spectrum of pathologies, like in the defence against infectious agents, in inflammation resolution, and wound repair. In the past several years, microRNAs (miRNAs) have been demonstrated to play important roles in immune diseases by regulating macrophage functions. In this review, we will summarize the role of miRNAs in the differentiation of monocytes into macrophages, in the classical and alternative activation of macrophages, and in the regulation of phagocytosis and apoptosis. Notably, miRNAs preferentially target genes related to the cellular cholesterol metabolism, which is of key importance for the inflammatory activation and phagocytic activity of macrophages. miRNAs functionally link various mechanisms involved in macrophage activation and contribute to initiation and resolution of inflammation. miRNAs represent promising diagnostic and therapeutic targets in different conditions, such as infectious diseases, atherosclerosis, and cancer.

TGF-β1 promotes scar fibroblasts proliferation and transdifferentiation via up-regulating MicroRNA-21

TGF-β1, upregulated in keloid tissue, promotes the proliferation, collagen formation and differentiation of dermal fibroblasts. miR-21 is one of microRNAs first found in human genome. The aim of our study is to explore the mechanisms of miR-21 in TGF-β1-induced scar fibroblasts proliferation and transdifferentiation. In the present study, first we found that TGF-β1 promoted scar fibroblasts proliferation and transdifferentiation via up-regulating miR-21 expression, which could be attenuated when miR-21 was inhibited. Overexpression of miR-21 had similar effect as TGF-β1 on proliferation and transdifferentiation. Additionally, TGF-β1 increased the expressions and activities of MMP2 and MMP9 in keloid fibroblasts, which was suppressed by miR-21 inhibition. Finally, the results demonstrated that PTEN/AKT signaling pathway played important role in TGF-β1-induced transdifferentiation. In conclusion, our study suggests that TGF-β1 promotes keloid fibroblasts proliferation and transdifferentiation via up-regulation of miR-21 and PTEN/AKT signalling pathway plays important role in this process, which provides a potential theoretical basis for clinical treatment of skin scars.

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

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

Multidimensional Contribution of Matrix Metalloproteinases to Atherosclerotic Plaque Vulnerability: Multiple Mechanisms of Inhibition to Promote Stability

The prevalence of atherosclerotic disease continues to increase, and despite significant reductions in major cardiovascular events with current medical interventions, an additional therapeutic window exists. Atherosclerotic plaque growth is a complex integration of cholesterol penetration, inflammatory cell infiltration, vascular smooth muscle cell (VSMC) migration, and neovascular invasion. A family of matrix-degrading proteases, the matrix metalloproteinases (MMPs), contributes to all phases of vascular remodeling. The contribution of specific MMPs to endothelial cell integrity and VSMC migration in atherosclerotic lesion initiation and progression has been confirmed by the increased expression of these proteases in plasma and plaque specimens. Endogenous blockade of MMPs by the tissue inhibitors of metalloproteinases (TIMPs) may attenuate proteolysis in some regions, but the progression of matrix degeneration suggests that MMPs predominate in atherosclerotic plaque, precipitating vulnerability. Plaque neovascularization also contributes to instability and, coupling the known role of MMPs in angiogenesis to that of atherosclerotic plaque growth, interest in targeting MMPs to facilitate plaque stabilization continues to accumulate. This article aims to review the contributions of MMPs and TIMPs to atherosclerotic plaque expansion, neovascularization, and rupture vulnerability with an interest in promoting targeted therapies to improve plaque stabilization and decrease the risk of major cardiovascular events.

Novel epigenetic-based therapies useful in cardiovascular medicine

Epigenetic modifications include DNA methylation, histone modifications, and microRNA. Gene alterations have been found to be associated with cardiovascular diseases, and epigenetic mechanisms are continuously being studied to find new useful strategies for the clinical management of afflicted patients. Numerous cardiovascular disorders are characterized by the abnormal methylation of CpG islands and so specific drugs that could inhibit DNA methyltransferase directly or by reducing its gene expression (e.g., hydralazine and procainamide) are currently under investigation. The anti-proliferative and anti-inflammatory properties of histone deacetylase inhibitors and their cardio-protective effects have been confirmed in preclinical studies. Furthermore, the regulation of the expression of microRNA targets through pharmacological tools is still under development. Indeed, large controlled trials are required to establish whether current possible candidate antisense microRNAs could offer better therapeutic benefits in clinical practice. Here, we updated therapeutic properties, side effects, and feasibility of emerging epigenetic-based strategies in cardiovascular diseases by highlighting specific problematic issues that still affect the development of large scale novel therapeutic protocols.

Regulatory roles of microRNA-21 in fibrosis through interaction with diverse pathways (Review)

MicroRNA-21 (miR-21) is a small, non-coding RNA which can regulate gene expression at the post‑transcriptional level. While the fibrogenic process is vital in tissue repair, proliferation and transition of fibrogenic cells combined with an imbalance of secretion and degradation of the extracellular matrix results in excessive tissue remodeling and fibrosis. Recent studies have indicated that miR‑21 is overexpressed during fibrosis and can regulate the fibrogenic process in a variety of organs and tissues via diverse pathways. The present review summarized the significant roles of miR-21 in fibrosis and discussed the underlying key pathways.

MicroRNA-185 inhibits angiogenesis in human microvascular endothelial cells through targeting stromal interaction molecule 1

Angiogenesis is a vital biological mechanism representing the adaptive response to a variety of pathological stimuli such as hypoxia. It is regulated by several pro-angiogenic and anti-angiogenic microRNAs. Studies have demonstrated an altered microRNA-185 (miR-185) expression in endothelial cells under hypoxic conditions; however, its role in angiogenesis has not been elucidated. We investigated the role of miR-185 in angiogenesis and found that miR-185 had an inhibitory effect on cell proliferation, migration, and tube formation. Stromal interaction molecule 1 (STIM1) appeared to be a direct target of miR-185 by computational prediction; this was confirmed by luciferase reporter assay. Silencing of the STIM1 gene was found to mimic miR-185-mediated inhibition of angiogenesis. STIM1 overexpression eliminated the anti-angiogenic effect of miR-185. Our study results suggest a direct interaction between miR-185 and STIM1 mRNA in microvascular endothelial cells. MicroRNA-185 acted as a negative regulator of angiogenesis in microvascular endothelial cells through downregulation of the STIM1 protein.

[MiRNAs in the diagnosis of cardiovascular diseases associated with type 2 diabetes mellitus and obesity]

Worldwide, the number of patients with type 2 diabetes mellitus (T2DM), obesity, and cardiovascular diseases (CVD) continues to increase steadily. Despite long-term studies of obesity and concomitant diseases, the molecular genetic bases for the development of these pathological conditions have remained the subject of numerous investigations so far. Recent investigations point to the involvement of miRNAs as dynamic modifiers of the pathogenesis of various pathological conditions, including obesity, T2DM, and CVD. MicroRNAs are involved in various biological processes underlying the development of CVDs, including endothelial dysfunction, cell adhesion, and atherosclerotic plaque formation and rupture. Some of them are considered as potential sensitive diagnostic markers of coronary heart disease and acute myocardial infarction. Approximately 1,000 microRNAs are found in the human body. It has been determined that miRNAs regulate 30% of all human genes. Among them there are about 50 circulating miRNAs presumably associated with cardiovascular diseases. This review provides recent data on the participation of some miRNAs in various pathological and physiological states associated with CVD in DM and obesity. An extended and exact understanding of the function of miRNAs in the gene regulatory networks associated with cardiovascular risk in obesity will be able to reveal new mechanisms for the progression of disease, to predict its development, and to elaborate innovative therapeutic strategies.

Small but smart: MicroRNAs orchestrate atherosclerosis development and progression

MicroRNAs (miRNAs) are short non-coding RNA able to bind specific sequences on target messenger RNAs (mRNAs) and thereby to post-transcriptionally modulate gene expression. Being expressed in all vertebrate cell types, miRNAs have emerged as key players in a wide array of biological processes, including cell proliferation, differentiation and apoptosis. Over the past decade, knowledge concerning the contribution of miRNAs to human pathology has grown with an astonishing pace. In particular, a major involvement of miRNAs in atherosclerosis as a leading cause of global mortality has been supported by ample evidence from in vitro, in vivo and clinical studies. This review aims to summarize and highlight current concepts of miRNA function in the continuum of atherogenesis ranging from risk factors (i.e. dyslipidemia, diabetes, hypertension), to endothelial dysfunction up to the events leading to plaque rupture. Areas in need for further research and potential perspectives for translational applications will be scrutinized. This article is part of a Special Issue entitled: MicroRNAs and lipid/energy metabolism and related diseases edited by Carlos Fernández-Hernando and Yajaira Suárez.

Differentially expressed microRNAs in kidney biopsies from various subtypes of nephrotic children

BACKGROUND

Our previous study showed a set of increased miRNAs in serum or urine from nephrotic syndrome children. In this study, we investigated the renal expression of these miRNAs in nephrotic children and explored their role in pathogenesis and as potential indicators to differentiate subtypes of kidney diseases.

METHODS

We enrolled 52 children with six different subtypes of nephropathy, and 8 normal kidney tissues were used as controls. RT-qPCR was used to quantify the expression of miR-191, miR-151-3p, miR-150, miR-30a-5p and miR-19b in renal tissues.

RESULTS

miR-191 and miR-151-3p exhibited significantly higher and lower intrarenal expression in all six subtypes of kidney diseases compared to controls. miR-19b was upregulated in three subtypes, and miR-30a-5p and miR-150 were downregulated in two and four subtypes, respectively. The intrarenal expression of miR-150 was significantly different between minimal change disease (MCD) and some other subtypes. The renal levels of these miRNAs correlated significantly with some renal functions and immune parameters. Bioinformatics showed that some target genes of these miRNAs were associated with immune and renal pathological changes.

CONCLUSIONS

These five miRNAs may be involved in the pathogenesis of nephropathy in children. miR-150 is a potential typing indictor to differentiate MCD from other nephropathy subtypes.

Correlation between genetic polymorphism of matrix metalloproteinase-9 in patients with coronary artery disease and cardiac remodeling

Objective:

To explore the correlation between genetic polymorphism of matrix metalloproteinase-9 (MMP-9) in patients with coronary artery disease (CAD) and cardiac remodeling.

Methods:

A total of 272 subjects who received coronary angiography in our hospital from July 2008 to September 2013 were selected, including 172 CAD patients (CAD group) and another 100 ones (control group). Both groups were subjected to MMP-9 and ultrasonic detections to determine vascular remodeling and atherosclerotic plaques. C1562G polymorphism of MMP-9 gene was detected, and correlation with vascular remodeling and atherosclerotic plaque was analyzed.

Results:

Serum MMP-9 level of CAD group (330.87±50.39 ng/ml) was significantly higher than that of control group (134.87±34.02 ng/ml) (P<0.05). Compared with control group, CAD group had significantly higher intima-media thickness, and significantly lower systolic peak velocity, mean systolic velocity and end-diastolic velocity (P<0.05). Total area of stenotic blood vessels was 67.34±22.98 mm², while that of control blood vessels was 64.00±20.83 mm². G/G, G/C and C/C genotype frequencies of MMP-9 differed significantly in the two groups (P<0.05). G and C allele frequencies of CAD group (70.9% and 29.1%) were significantly different from those of control group (50.0% and 50.0%) (P<0.05). G/G, G/C and C/C genotypes were manifested as lipid-rich, fibrous and calcified or ulcerated plaques respectively. Total area of stenotic blood vessels of G/G genotype significantly exceeded those of G/C and C/C genotypes (P<0.05), whereas the latter two had no significant differences.

Conclusion:

CAD promoted 1562C-G transformation of MMP-9 gene into genetic polymorphism, thus facilitating arterial remodeling and increasing unstable atherosclerotic plaques.

MiR-21 overexpression improves osteoporosis by targeting RECK

Osteoporosis is a kind of metabolic bone disorder. MicroRNA-21 (miR-21) has been proven to play an important role in bone formation, whereas its role in osteoporosis is unclear. In the present study, miR-21 expression was inhibited by TNF-α in mesenchymal stem cells (MSCs). TNF-α induced cell apoptosis, and inhibited cell proliferation and differentiation of MSCs. Whereas the effect was reversed by miR-21 mimics. Expression of reversion-inducing cysteine-rich protein with Kazal motifs (RECK) which is a predicted target of miR-21 was inhibited by miR-21 mimics. A luciferase reporter gene assay showed that miR-21 directly bound to RECK 3'-UTR. The effect of TNF-α on MSCs was reversed by RECK siRNA which was consistent with miR-21 mimics. The expression of MT1-MMP was inhibited by TNF-α and enhanced by RECK siRNA and miR-21 mimics. For the in vivo study, an osteoporosis model (OVX) was established by bilateral oophorectomy in mice. The expression of miR-21 decreased and RECK increased in the OVX mice. When treated with lentiviral RECK shRNA, the osteocalcin concentration and alkaline phosphate activity of the OVX mice decreased. The bone mineral density of the right femur mid-diaphysis was improved by RECK shRNA. Collectively, miR-21 modulated the osteoporosis by targeting RECK. These results emphasize the role of miR-21 during osteoporosis and suggest RECK might be a new medical target for osteoporosis.

MicroRNA-21 promotes osteogenic differentiation by targeting small mothers against decapentaplegic 7

Previous studies have suggested that microRNAs (miRNAs/miRs) may positively or negatively control osteogenic differentiation and mineralization by targeting negative regulators of osteogenesis or important osteogenic factors. miR-21 is important in osteoblast differentiation and Smad7 is a critical regulator of osteogenic differentiation, which inhibits proliferation, differentiation and mineralization in mouse osteoblast cells. However, the association between Smad7 and miR-21 remain to be elucidated. In the present study, miR-21 was found to promote the level of osteogenic differentiation and increase matrix mineralization in MC3T3-E1 cells. Furthermore, Smad7 was identified as a direct target of miR-21 in the MC3T3-E1 cells. The overexpression of miR-21 affected the protein levels of SMAD7, but not the mRNA levels, which suggested that miR-21 regulates the levels of SMAD7 by inhibiting translation, rather than by promoting mRNA decay. Forced expression of miR-21 promoted osteogenic differentiation and mineralization, while inhibition of miR-21 suppressed these processes. The present study also identified for the first time, to the best of our knowledge, the promotion of osteogenic differentiation and mineralization by miR-21, by repressing the expression of Smad7.

MicroRNAs and cardiovascular diseases

Coronary artery diseases (CAD) and heart failure have high mortality rate in the world, although much progress has been made in this field in last two decades. There is still a clinical need for a novel diagnostic approach and a therapeutic strategy to decrease the incidence of CAD. MicroRNAs (miRNAs) are highly conserved noncoding small RNA molecules that regulate a large fraction of the genome by binding to complementary messenger RNA sequences, resulting in posttranscriptional gene silencing. Recent studies have shown that specific miRNAs are involved in whole stage of atherosclerosis, from endothelium dysfunction to plaque rupture. These findings suggest that miRNAs are potential biomarkers in early diagnosis and therapeutic targets in CAD. In the present review, we highlight the role of miRNAs in every stage of atherosclerosis, and discuss the prospects of miRNAs in the near future.

Epigenetic reprogramming in atherosclerosis

Recent data support the involvement of epigenetic alterations in the pathogenesis of atherosclerosis. The most widely investigated epigenetic mechanism is DNA methylation although also histone code changes occur during the diverse steps of atherosclerosis, such as endothelial cell proliferation, vascular smooth muscle cell (SMC) differentiation, and inflammatory pathway activation. In this review, we focus on the main genes that are epigenetically modified during the atherogenic process, particularly nitric oxide synthase (NOS), estrogen receptors (ERs), collagen type XV alpha 1 (COL15A1), vascular endothelial growth factor receptor (VEGFR), and ten-eleven translocation (TET), which are involved in endothelial dysfunction; gamma interferon (IFN-γ), forkhead box p3 (FOXP3), and tumor necrosis factor-α (TNF-α), associated with atherosclerotic inflammatory process; and p66shc, lectin-like oxLDL receptor (LOX1), and apolipoprotein E (APOE) genes, which are regulated by high cholesterol and homocysteine (Hcy) levels. Furthermore, we also discuss the role of non-coding RNAs (ncRNA) in atherosclerosis. NcRNAs are involved in epigenetic regulation of endothelial function, SMC proliferation, cholesterol synthesis, lipid metabolism, and inflammatory response.