MicroRNA-210 Enhances Fibrous Cap Stability in Advanced Atherosclerotic Lesions

Polycyclic aromatic hydrocarbons exposure and arterial stiffness-related plasma miRNAs: A panel study

The underlying mechanisms between polycyclic aromatic hydrocarbons (PAHs) exposure and arterial stiffness are poorly understood. We carried out a panel study involving three repeated surveys to examine the associations of individual and mixture of PAHs exposure with arterial stiffness-related miRNAs among 123 community adults. In linear mixed-effect (LME) models, we found that urinary 9-hydroxyfluorene (9-OHFlu), 2-hydroxyphenanthrene (2-OHPh), 9-hydroxyphenanthrene (9-OHPh) at lag 0 day were positively linked to miR-146a and/or miR-222. The Bayesian kernel machine regression (BKMR) analyses revealed positive overall associations of PAHs mixture at lag 0 day with miR-146a and miR-222, and urinary 9-OHFlu contributed the most. In addition, an inter-quartile range (IQR) increase in urinary 9-OHFlu at lag 0 day was associated with elevated miR-146a and miR-222 by 0.16 (95% CI: 0.02, 0.30) to 0.34 (95% CI: 0.13, 0.54). Accordingly, exposure to PAHs, especially 9-OHFlu at lag 0 day, was related to elevated arterial stiffness-related plasma miRNAs.

Correlation analysis of serum miR-145 and miR-210 with carotid artery stenosis and their predictive value for cerebral ischemic events

OBJECTIVE

To analyze the significance of serum miR-145 and miR-210 expression levels in the diagnosis of carotid artery stenosis.

METHODS

During the same period, 55 healthy individuals who received physical examination in the same hospital were recruited as controls and assigned to a non-stenosis group. Among the included patients, there were 45 cases of mild stenosis, 14 cases of moderate stenosis, and 6 cases of severe stenosis after carotid color Doppler ultrasonography. The expression levels of miR-145 and miR-210 in serum were measured using real-time fluorescence quantitative polymerase chain reaction (qPCR) technology.

RESULTS

The expression levels of serum miR-145 and miR-210 in carotid artery stenosis group were significantly lower than those in non-stenosis group (p < 0.001). Multivariate Logistic regression analysis showed that smoking history, diabetes, hypertension and total cholesterol were positively correlated with the occurrence of carotid artery stenosis (p < 0.05). The expression levels of miR-145 and miR-210 were significantly negatively correlated with carotid artery stenosis (p < 0.001). In addition, patients with carotid artery stenosis and low expression levels of miR-145 and miR-210 had a greater risk of cerebral ischemia (p < 0.05). Cox regression analysis showed that the low expression of miR-145 and miR-210 were independent predictors of cerebral ischemic events. ROC analysis confirmed that miR-145 and miR-210 had good diagnostic efficacy in cerebral ischemia (p < 0.001).

CONCLUSION

The decreased expression of miR-145 and miR-210 in serum is closely related to the diagnostic significance of carotid artery stenosis, and may be used to predict the occurrence of cerebral ischemic events.

Utilization of an Artery-on-a-Chip to Unravel Novel Regulators and Therapeutic Targets in Vascular Diseases

In this study, organ-on-chip technology is used to develop an in vitro model of medium-to-large size arteries, the artery-on-a-chip (AoC), with the objective to recapitulate the structure of the arterial wall and the relevant hemodynamic forces affecting luminal cells. AoCs exposed either to in vivo-like shear stress values or kept in static conditions are assessed to generate a panel of novel genes modulated by shear stress. Considering the crucial role played by shear stress alterations in carotid arteries affected by atherosclerosis (CAD) and abdominal aortic aneurysms (AAA) disease development/progression, a patient cohort of hemodynamically relevant specimens is utilized, consisting of diseased and non-diseased (internal control) vessel regions from the same patient. Genes activated by shear stress follow the same expression pattern in non-diseased segments of human vessels. Single cell RNA sequencing (scRNA-seq) enables to discriminate the unique cell subpopulations between non-diseased and diseased vessel portions, revealing an enrichment of flow activated genes in structural cells originating from non-diseased specimens. Furthermore, the AoC served as a platform for drug-testing. It reproduced the effects of a therapeutic agent (lenvatinib) previously used in preclinical AAA studies, therefore extending the understanding of its therapeutic effect through a multicellular structure.

Wnt Signaling in Atherosclerosis: Mechanisms to Therapeutic Implications

Atherosclerosis is a vascular disease in which inflammation plays a pivotal role. Receptor-mediated signaling pathways regulate vascular inflammation and the pathophysiology of atherosclerosis. Emerging evidence has revealed the role of the Wnt pathway in atherosclerosis progression. The Wnt pathway influences almost all stages of atherosclerosis progression, including endothelial dysfunction, monocyte infiltration, smooth muscle cell proliferation and migration, and plaque formation. Targeting the Wnt pathway to treat atherosclerosis represents a promising therapeutic approach that remains understudied. Blocking Wnt signaling utilizing small molecule inhibitors, recombinant proteins, and/or neutralizing antibodies ameliorates atherosclerosis in preclinical models. The Wnt pathway can be potentially manipulated through targeting Wnt ligands, receptors, co-receptors, and downstream signaling molecules. However, there are challenges associated with developing a real world therapeutic compound that targets the Wnt pathway. This review focuses on the role of Wnt signaling in atherosclerosis development, and the rationale for targeting this pathway for the treatment of atherosclerosis.

RNA interference-based therapies for atherosclerosis: Recent advances and future prospects

Atherosclerosis represents a pathological state that affects the arterial system of the organism. This chronic, progressive condition is typified by the accumulation of atheroma within arterial walls. Modulation of RNA molecules through RNA-based therapies has expanded the range of therapeutic options available for neurodegenerative diseases, infectious diseases, cancer, and, more recently, cardiovascular disease (CVD). Presently, microRNAs and small interfering RNAs (siRNAs) are the most widely employed therapeutic strategies for targeting RNA molecules, and for regulating gene expression and protein production. Nevertheless, for these agents to be developed into effective medications, various obstacles must be overcome, including inadequate binding affinity, instability, challenges of delivering to the tissues, immunogenicity, and off-target toxicity. In this comprehensive review, we discuss in detail the current state of RNA interference (RNAi)-based therapies.

Anti-atherosclerosis mechanisms associated with regulation of non-coding RNAs by active monomers of traditional Chinese medicine

Atherosclerosis is the leading cause of numerous cardiovascular diseases with a high mortality rate. Non-coding RNAs (ncRNAs), RNA molecules that do not encode proteins in human genome transcripts, are known to play crucial roles in various physiological and pathological processes. Recently, researches on the regulation of atherosclerosis by ncRNAs, mainly including microRNAs, long non-coding RNAs, and circular RNAs, have gradually become a hot topic. Traditional Chinese medicine has been proved to be effective in treating cardiovascular diseases in China for a long time, and its active monomers have been found to target a variety of atherosclerosis-related ncRNAs. These active monomers of traditional Chinese medicine hold great potential as drugs for the treatment of atherosclerosis. Here, we summarized current advancement of the molecular pathways by which ncRNAs regulate atherosclerosis and mainly highlighted the mechanisms of traditional Chinese medicine monomers in regulating atherosclerosis through targeting ncRNAs.

Nucleus Pulposus-Targeting Nanocarriers Facilitate Mirna-Based Therapeutics for Intervertebral Disc Degeneration

Intervertebral disc degeneration (IDD) is a common cause of low back pain. Understanding its molecular mechanisms is the basis for developing specific treatment. To demonstrate that miR-22-3p is critical in the regulation of IDD, miRNA microarray analyses are conducted in conjunction with in vivo and in vitro experiments. The miR-22-3p knockout (KO) mice show a marked decrease in the histological scores. Bioinformatic analysis reveals that miR-22-3p plays a mechanistic role in the development of IDD by targeting SIRT1, which in turn activates the JAK1/STAT3 signaling pathway. This is confirmed by a luciferase reporter assay and western blot analysis. Therapeutically, the delivery of miR-22-3p inhibitors and mimics through the synthesized nanoparticles in the IDD model alleviates and aggravates IDD, respectively. The nanocarriers enhance transportation of miR-22-3p to nucleus pulposus cells, thus enabling the in vivo inhibition of miR-22-3p for therapeutic purposes and consequently promoting the development of miRNA-specific drugs for IDD.

ADAMTS-7 Modulates Atherosclerotic Plaque Formation by Degradation of TIMP-1

BACKGROUND

The ADAMTS7 locus was genome-wide significantly associated with coronary artery disease. Lack of the ECM (extracellular matrix) protease ADAMTS-7 (A disintegrin and metalloproteinase-7) was shown to reduce atherosclerotic plaque formation. Here, we sought to identify molecular mechanisms and downstream targets of ADAMTS-7 mediating the risk of atherosclerosis.

METHODS

Targets of ADAMTS-7 were identified by high-resolution mass spectrometry of atherosclerotic plaques from Apoe-/- and Apoe-/-Adamts7-/- mice. ECM proteins were identified using solubility profiling. Putative targets were validated using immunofluorescence, in vitro degradation assays, coimmunoprecipitation, and Förster resonance energy transfer-based protein-protein interaction assays. ADAMTS7 expression was measured in fibrous caps of human carotid artery plaques.

RESULTS

In humans, ADAMTS7 expression was higher in caps of unstable as compared to stable carotid plaques. Compared to Apoe-/- mice, atherosclerotic aortas of Apoe-/- mice lacking Adamts-7 (Apoe-/-Adamts7-/-) contained higher protein levels of Timp-1 (tissue inhibitor of metalloprotease-1). In coimmunoprecipitation experiments, the catalytic domain of ADAMTS-7 bound to TIMP-1, which was degraded in the presence of ADAMTS-7 in vitro. ADAMTS-7 reduced the inhibitory capacity of TIMP-1 at its canonical target MMP-9 (matrix metalloprotease-9). As a downstream mechanism, we investigated collagen content in plaques of Apoe-/- and Apoe-/-Adamts7-/- mice after a Western diet. Picrosirius red staining of the aortic root revealed less collagen as a readout of higher MMP-9 activity in Apoe-/- as compared to Apoe-/- Adamts7-/- mice. To facilitate high-throughput screening for ADAMTS-7 inhibitors with the aim of decreasing TIMP-1 degradation, we designed a Förster resonance energy transfer-based assay targeting the ADAMTS-7 catalytic site.

CONCLUSIONS

ADAMTS-7, which is induced in unstable atherosclerotic plaques, decreases TIMP-1 stability reducing its inhibitory effect on MMP-9, which is known to promote collagen degradation and is likewise associated with coronary artery disease. Disrupting the interaction of ADAMTS-7 and TIMP-1 might be a strategy to increase collagen content and plaque stability for the reduction of atherosclerosis-related events.

Uncovering Candidate mRNAs, Signaling Pathways and Immune Cells in Atherosclerotic Plaque and Ischemic Stroke

Background

The specific molecular mechanistic link between atherosclerotic plaques and ischemic stroke (IS) is not clear. The aim of this study is to explore the potential molecular relationship between atherosclerotic plaques and IS.

Methods

All data were downloaded from the Gene Expression Omnibus (GEO) database. Key hub differentially expressed mRNAs (DEmRNAs) related to atherosclerotic plaques and IS were identified by differential expression analysis and least absolute shrinkage and selection operator (LASSO) analysis. Subsequently, a diagnostic model was established based on the expression of key hub DEmRNAs and logistic regression. In order to understand the molecular mechanism of key hub DEmRNAs, the transcription factor (TF) regulatory network and mRNA-miRNA-lncRNA regulatory network were also constructed. In addition, functional enrichment analysis and single-sample Gene Set Enrichment Analysis (ssGSEA) analysis were also performed.

Results

Four key hub DEmRNAs (ADCY3, CLDN7, PPM1B and RRAS2) were identified by differential expression analysis and LASSO analysis. Moreover, the diagnostic model based on four key hub DEmRNAs has excellent diagnostic accuracy. We also found that Type 1 T helper cell may be associated with IS caused by atherosclerosis based on ssGSEA analysis. In the mRNA-miRNA-lncRNA regulatory network, we found that multiple signaling axes such as RRAS2-hsa-miR-3150b-3p-ILF3-AS1, PPM1B-hsa-miR-541-5p-LINC00294, CLDN7-hsa-miR-184-LINC00467 and ADCY3-hsa-miR-488-3p-URB1-AS1 may play an important role in the progression of IS. In addition, some signaling pathways, including chemokine signaling pathway, MAPK signaling pathway and cAMP signaling pathway, may be involved in regulating IS.

Conclusion

The identified key molecules, signaling pathways and immune cells may help to provide a theoretical basis for exploring the relationship between atherosclerotic plaque and the progression of IS.

Knockdown of circ_0113656 assuages oxidized low-density lipoprotein-induced vascular smooth muscle cell injury through the miR-188-3p/IGF2 pathway

Circular RNA (circRNA) is involved in the pathogenesis of atherosclerosis (AS). The present work analyzed the RNA expression of circ_0113656, microRNA-188-3p (miR-188-3p), and insulin-like growth factor 2 (IGF2) by quantitative real-time polymerase chain reaction. The protein expression of proliferating cell nuclear antigen (PCNA), matrix metalloprotein 2 (MMP2), and IGF2 was detected by Western blotting. Cell viability, proliferation, invasion, and migration were analyzed using the cell counting kit-8, 5-ethynyl-2'-deoxyuridine, transwell invasion, and wound-healing assays, respectively. The interactions among circ_0113656, miR-188-3p, and IGF2 were identified by dual-luciferase reporter assay and RNA immunoprecipitation assay. The results showed that circ_0113656 and IGF2 expression were significantly upregulated, while miR-188-3p was downregulated in the blood of AS patients and oxidized low-density lipoprotein (ox-LDL)-treated HVSMCs in comparison with controls. The ox-LDL treatment induced HVSMC proliferation, migration, and invasion accompanied by increases in PCNA and MMP2 expression; however, these effects were attenuated after circ_0113656 knockdown. Circ_0113656 acted as a miR-188-3p sponge and it regulated ox-LDL-induced HVSMC disorders by binding to miR-188-3p. Besides, the regulation of miR-188-3p in ox-LDL-induced HVSMC injury involved IGF2. Further, the depletion of circ_0113656 inhibited IGF2 expression by interacting with miR-188-3p. Thus, the circ_0113656/miR-188-3p/IGF2 axis may mediate ox-LDL-induced HVSMC disorders in AS, providing a new therapeutic strategy for AS.

Targeting long non-coding RNA NUDT6 enhances smooth muscle cell survival and limits vascular disease progression

Long non-coding RNAs (lncRNAs) orchestrate various biological processes and regulate the development of cardiovascular diseases. Their potential therapeutic benefit to tackle disease progression has recently been extensively explored. Our study investigates the role of lncRNA Nudix Hydrolase 6 (NUDT6) and its antisense target fibroblast growth factor 2 (FGF2) in two vascular pathologies: abdominal aortic aneurysms (AAA) and carotid artery disease. Using tissue samples from both diseases, we detected a substantial increase of NUDT6, whereas FGF2 was downregulated. Targeting Nudt6 in vivo with antisense oligonucleotides in three murine and one porcine animal model of carotid artery disease and AAA limited disease progression. Restoration of FGF2 upon Nudt6 knockdown improved vessel wall morphology and fibrous cap stability. Overexpression of NUDT6 in vitro impaired smooth muscle cell (SMC) migration, while limiting their proliferation and augmenting apoptosis. By employing RNA pulldown followed by mass spectrometry as well as RNA immunoprecipitation, we identified Cysteine and Glycine Rich Protein 1 (CSRP1) as another direct NUDT6 interaction partner, regulating cell motility and SMC differentiation. Overall, the present study identifies NUDT6 as a well-conserved antisense transcript of FGF2. NUDT6 silencing triggers SMC survival and migration and could serve as a novel RNA-based therapeutic strategy in vascular diseases.

A comparative gene expression matrix in Apoe-deficient mice identifies unique and atherosclerotic disease stage-specific gene regulation patterns in monocytes and macrophages

BACKGROUND AND AIMS

Atherosclerosis is a systemic and chronic inflammatory disease propagated by monocytes and macrophages. Yet, our knowledge on how transcriptome of these cells evolves in time and space is limited. We aimed at characterizing gene expression changes in site-specific macrophages and in circulating monocytes during the course of atherosclerosis.

METHODS

We utilized apolipoprotein E-deficient mice undergoing one- and six-month high cholesterol diet to model early and advanced atherosclerosis. Aortic macrophages, peritoneal macrophages, and circulating monocytes from each mouse were subjected to bulk RNA-sequencing (RNA-seq). We constructed a comparative directory that profiles lesion- and disease stage-specific transcriptomic regulation of the three cell types in atherosclerosis. Lastly, the regulation of one gene, Gpnmb, whose expression positively correlated with atheroma growth, was validated using single-cell RNA-seq (scRNA-seq) of atheroma plaque from murine and human.

RESULTS

The convergence of gene regulation between the three investigated cell types was surprisingly low. Overall 3245 differentially expressed genes were involved in the biological modulation of aortic macrophages, among which less than 1% were commonly regulated by the remote monocytes/macrophages. Aortic macrophages regulated gene expression most actively during atheroma initiation. Through complementary interrogation of murine and human scRNA-seq datasets, we showcased the practicality of our directory, using the selected gene, Gpnmb, whose expression in aortic macrophages, and a subset of foamy macrophages in particular, strongly correlated with disease advancement during atherosclerosis initiation and progression.

CONCLUSIONS

Our study provides a unique toolset to explore gene regulation of macrophage-related biological processes in and outside the atheromatous plaque at early and advanced disease stages.

Circadian system microRNAs - Role in the development of cardiovascular diseases

Circadian rhythm regulates numerous physiological processes, and disruption of the circadian clock can lead to cardiovascular disease. Cardiovascular disease is the leading cause of morbidity and mortality worldwide. Small non-coding RNAs, microRNAs (miRNAs), are involved in regulating gene expression, both those important for the cardiovascular system and key circadian clock genes. Epigenetic mechanisms based on miRNAs are essential for fine-tuning circadian physiology. Indeed, some miRNAs depend on circadian periodicity, others are under the influence of light, and still others are under the influence of core clock genes. Dysregulation of miRNAs involved in circadian rhythm modulation has been associated with inflammatory conditions of the endothelium and atherosclerosis, which can lead to coronary heart disease and myocardial infarction. Epigenetic processes are reversible through their association with environmental factors, enabling innovative preventive and therapeutic strategies for cardiovascular disease. Here, is a review of recent findings on how miRNAs modulate circadian rhythm desynchronization in cardiovascular disease. In the era of personalized medicine, the possibility of treatment with miRNA antagomirs should be time-dependent to correspond to chronotherapy and achieve the most significant efficacy.

In silico analysis reveals hypoxia-induced miR-210-3p specifically targets SARS-CoV-2 RNA

Human coronaviruses (HCoVs) until the emergence of SARS in 2003 were associated with mild cold and upper respiratory tract infections. The ongoing pandemic caused by SARS-CoV-2 has enhanced the potential for infection and transmission as compared to other known members of this family. MicroRNAs (miRNA) are 21-25 nucleotides long non-coding RNA that bind to 3' UTR of genes and regulate almost every aspect of cellular function. Several human miRNAs have been known to target viral genomes, mostly to downregulate their expression and sometimes to upregulate also. In some cases, host miRNAs could be sequestered by the viral genome to create a condition for favourable virus existence. The ongoing SARS CoV-2 pandemic is unique based on its transmissibility and severity and we hypothesised that there could be a unique mechanism for its pathogenesis. In this study, we exploited in silico approach to identify human respiratory system-specific miRNAs targeting the viral genome of three highly pathogenic HCoVs (SARS-CoV-2 Wuhan strain, SARS-CoV, and MERS-CoV) and three low pathogenic HCoVs (OC43, NL63, and HKU1). We identified ten common microRNAs that target all HCoVs studied here. In addition, we identified unique miRNAs which targeted specifically one particular HCoV. miR-210-3p was the single unique lung-specific miRNA, which was found to target the NSP3, NSP4, and NSP13 genes of SARS-CoV-2. Further miR-210-NSP3, miR-210-NSP4, and miR-210-NSP13 SARS-CoV-2 duplexes were docked with the hAGO2 protein (PDB ID 4F3T) which showed Z-score values of -1.9, -1.7, and -1.6, respectively. The role of miR-210-3p as master hypoxia regulator and inflammation regulation may be important for SARS-CoV-2 pathogenesis. Overall, this analysis advocates that miR-210-3p be investigated experimentally in SARS-CoV-2 infection.Communicated by Ramaswamy H. Sarma.

microRNAs Associated with Carotid Plaque Development and Vulnerability: The Clinician's Perspective

Ischemic stroke (IS) related to atherosclerosis of large arteries is one of the leading causes of mortality and disability in developed countries. Atherosclerotic internal carotid artery stenosis (ICAS) contributes to 20% of all cerebral ischemia cases. Nowadays, atherosclerosis prevention and treatment measures aim at controlling the atherosclerosis risk factors, or at the interventional (surgical or endovascular) management of mature occlusive lesions. There is a definite lack of the established circulating biomarkers which, once modulated, could prevent development of atherosclerosis, and consequently prevent the carotid-artery-related IS. Recent studies emphasize that microRNA (miRNA) are the emerging particles that could potentially play a pivotal role in this approach. There are some research studies on the association between the expression of small non-coding microRNAs with a carotid plaque development and vulnerability. However, the data remain inconsistent. In addition, all major studies on carotid atherosclerotic plaque were conducted on cell culture or animal models; very few were conducted on humans, whereas the accumulating evidence demonstrates that it cannot be automatically extrapolated to processes in humans. Therefore, this paper aims to review the current knowledge on how miRNA participate in the process of carotid plaque formation and rupture, as well as stroke occurrence. We discuss potential target miRNA that could be used as a prognostic or therapeutic tool.

GPR55 in B cells limits atherosclerosis development and regulates plasma cell maturation

Dissecting the pathways regulating the adaptive immune response in atherosclerosis is of particular therapeutic interest. Here we report that the lipid G-protein coupled receptor GPR55 is highly expressed by splenic plasma cells (PC), upregulated in mouse spleens during atherogenesis and human unstable or ruptured compared to stable plaques. Gpr55-deficient mice developed larger atherosclerotic plaques with increased necrotic core size compared to their corresponding controls. Lack of GPR55 hyperactivated B cells, disturbed PC maturation and resulted in immunoglobulin (Ig)G overproduction. B cell-specific Gpr55 depletion or adoptive transfer of Gpr55-deficient B cells was sufficient to promote plaque development and elevated IgG titers. In vitro, the endogenous GPR55 ligand lysophsophatidylinositol (LPI) enhanced PC proliferation, whereas GPR55 antagonism blocked PC maturation and increased their mitochondrial content. Collectively, these discoveries provide previously undefined evidence for GPR55 in B cells as a key modulator of the adaptive immune response in atherosclerosis.

Regulatory role of miRNAs in Wnt signaling pathway linked with cardiovascular diseases

MicroRNAs (miRNAs) are discovered in science about 23 years ago. These are short, a series of non-coding, single-stranded and evolutionary conserved RNA molecules found in eukaryotic cells. It involved post-transcriptional fine-tune protein expression and repressing the target of mRNA in different biological processes. These miRNAs binds with the 3'-UTR region of specific mRNAs to phosphorylate the mRNA degradation and inhibit the translation process in various tissues. Therefore, aberrant expression in miRNAs induces numerous cardiovascular diseases and developmental defects. Subsequently, the miRNAs and Wnt singling pathway are regulating a cellular process in cardiac development and regeneration, maintain the homeostasis and associated heart diseases. In Wnt signaling pathway majority of the signaling components are expressed and regulated by miRNAs, whereas the inhibition or dysfunction of the Wnt signaling pathway induces cardiovascular diseases. Moreover, inadequate studies about the important role of miRNAs in heart development and diseases through Wnt signaling pathway has been exist still now. For this reason in present review we summarize and update the involvement of miRNAs and the role of Wnt signaling in cardiovascular diseases. We have discussed the mechanism of miRNA functions which regulates the Wnt components in cellular signaling pathway. The fundamental understanding of Wnt signaling regulation and mechanisms of miRNAs is quite essential for study of heart development and related diseases. This approach definitely enlighten the future research to provide a new strategy for formulation of novel therapeutic approaches against cardiovascular diseases.

miR-223 Exerts Translational Control of Proatherogenic Genes in Macrophages

A significant burden of atherosclerotic disease is driven by inflammation. Recently, microRNAs (miRNAs) have emerged as important factors driving and protecting from atherosclerosis. miR-223 regulates cholesterol metabolism and inflammation via targeting both cholesterol biosynthesis pathway and NF_kB signaling pathways; however, its role in atherosclerosis has not been investigated. We hypothesize that miR-223 globally regulates core inflammatory pathways in macrophages in response to inflammatory and atherogenic stimuli thus limiting the progression of atherosclerosis.

Clinical Parameters and Epigenetic Biomarkers of Plaque Vulnerability in Patients with Carotid Stenosis

Atheromatous disease is the first cause of death and dependency in developed countries and carotid artery atherosclerosis is one of the main causes of severe ischaemic strokes. Current management strategies are mainly based on the degree of stenosis and patient selection has limited accuracy. This information could be complemented by the identification of biomarkers of plaque vulnerability, which would permit patients at greater and lesser risk of stroke to be distinguished, thus enabling a better selection of patients for surgical or intensive medical treatment. Although several circulating protein-based biomarkers with significance for both the diagnosis of carotid artery disease and its prognosis have been identified, at present, none have been clinically implemented. This review focuses especially on the most relevant clinical parameters to take into account in routine clinical practice and summarises the most up-to-date data on epigenetic biomarkers of carotid atherosclerosis and plaque vulnerability.

Pathogenic role of microRNAs in atherosclerotic ischemic stroke: Implications for diagnosis and therapy

Ischemic stroke resulting from atherosclerosis (particularly in the carotid artery) is one of the major subtypes of stroke and has a high incidence of death. Disordered lipid homeostasis, lipid deposition, local macrophage infiltration, smooth muscle cell proliferation, and plaque rupture are the main pathological processes of atherosclerotic ischemic stroke. Hepatocytes, macrophages, endothelial cells and vascular smooth muscle cells are the main cell types participating in these processes. By inhibiting the expression of the target genes in these cells, microRNAs play a key role in regulating lipid disorders and atherosclerotic ischemic stroke. In this article, we listed the microRNAs implicated in the pathology of atherosclerotic ischemic stroke and aimed to explain their pro- or antiatherosclerotic roles. Our article provides an update on the potential diagnostic use of miRNAs for detecting growing plaques and impending clinical events. Finally, we provide a perspective on the therapeutic use of local microRNA delivery and discuss the challenges for this potential therapy.

Novel Biomarkers of Atherosclerotic Vascular Disease-Latest Insights in the Research Field

The atherosclerotic vascular disease is a cardiovascular continuum in which the main role is attributed to atherosclerosis, from its appearance to its associated complications. The increasing prevalence of cardiovascular risk factors, population ageing, and burden on both the economy and the healthcare system have led to the development of new diagnostic and therapeutic strategies in the field. The better understanding or discovery of new pathophysiological mechanisms and molecules modulating various signaling pathways involved in atherosclerosis have led to the development of potential new biomarkers, with key role in early, subclinical diagnosis. The evolution of technological processes in medicine has shifted the attention of researchers from the profiling of classical risk factors to the identification of new biomarkers such as midregional pro-adrenomedullin, midkine, stromelysin-2, pentraxin 3, inflammasomes, or endothelial cell-derived extracellular vesicles. These molecules are seen as future therapeutic targets associated with decreased morbidity and mortality through early diagnosis of atherosclerotic lesions and future research directions.

The Endothelium as a Hub for Cellular Communication in Atherogenesis: Is There Directionality to the Message?

Endothelial cells line every blood vessel and thereby serve as an interface between the blood and the vessel wall. They have critical functions for maintaining homeostasis and orchestrating vascular pathogenesis. Atherosclerosis is a chronic disease where cholesterol and inflammatory cells accumulate in the artery wall below the endothelial layer and ultimately form plaques that can either progress to occlude the lumen or rupture with thromboembolic consequences – common outcomes being myocardial infarction and stroke. Cellular communication lies at the core of this process. In this review, we discuss traditional (e.g., cytokines, chemokines, nitric oxide) and novel (e.g., extracellular vesicles) modes of endothelial communication with other endothelial cells as well as circulating and vessel wall cells, including monocytes, macrophages, neutrophils, vascular smooth muscle cells and other immune cells, in the context of atherosclerosis. More recently, the growing appreciation of endothelial cell plasticity during atherogenesis suggests that communication strategies are not static. Here, emerging data on transcriptomics in cells during the development of atherosclerosis are considered in the context of how this might inform altered cell-cell communication. Given the unique position of the endothelium as a boundary layer that is activated in regions overlying vascular inflammation and atherosclerotic plaque, there is a potential to exploit the unique features of this group of cells to deliver therapeutics that target the cellular crosstalk at the core of atherosclerotic disease. Data are discussed supporting this concept, as well as inherent pitfalls. Finally, we briefly review the literature for other regions of the body (e.g., gut epithelium) where cells similarly exist as a boundary layer but provide discrete messages to each compartment to govern homeostasis and disease. In this light, the potential for endothelial cells to communicate in a directional manner is explored, along with the implications of this concept – from fundamental experimental design to biomarker potential and therapeutic targets.

miR-210 hypoxamiR in Angiogenesis and Diabetes

Significance: microRNA-210 (miR-210) is the master hypoxia-inducible miRNA (hypoxamiR) since it has been found to be significantly upregulated under hypoxia in a wide range of cell types. Recent advances: Gene ontology analysis of its targets indicates that miR-210 modulates several aspects of cellular response to hypoxia. Due to its high pleiotropy, miR-210 not only plays a protective role by fine-tuning mitochondrial metabolism and inhibiting red-ox imbalance and apoptosis, but it can also promote cell proliferation, differentiation, and migration, substantially contributing to angiogenesis. Critical issues: As most miRNAs, modulating different gene pathways, also miR-210 can potentially lead to different and even opposite effects, depending on the physio-pathological contexts in which it acts. Future direction: The use of miRNAs as therapeutics is a fast growing field. This review aimed at highlighting the role of miR-210 in angiogenesis in the context of ischemic cardiovascular diseases and diabetes in order to clarify the molecular mechanisms underpinning miR-210 action. Particular attention will be dedicated to experimentally validated miR-210 direct targets involved in cellular processes related to angiogenesis and diabetes mellitus, such as mitochondrial metabolism, redox balance, apoptosis, migration, and adhesion. Antioxid. Redox Signal. 36, 685-706.

Interferon regulatory factor-5-dependent CD11c+ macrophages contribute to the formation of rupture-prone atherosclerotic plaques

AIMS

Inflammation is a key factor in atherosclerosis. The transcription factor interferon regulatory factor-5 (IRF5) drives macrophages towards a pro-inflammatory state. We investigated the role of IRF5 in human atherosclerosis and plaque stability.

METHODS AND RESULTS

Bulk RNA sequencing from the Carotid Plaque Imaging Project biobank were used to mine associations between major macrophage associated genes and transcription factors and human symptomatic carotid disease. Immunohistochemistry, proximity extension assays, and Helios cytometry by time of flight (CyTOF) were used for validation. The effect of IRF5 deficiency on carotid plaque phenotype and rupture in ApoE-/- mice was studied in an inducible model of plaque rupture. Interferon regulatory factor-5 and ITGAX/CD11c were identified as the macrophage associated genes with the strongest associations with symptomatic carotid disease. Expression of IRF5 and ITGAX/CD11c correlated with the vulnerability index, pro-inflammatory plaque cytokine levels, necrotic core area, and with each other. Macrophages were the predominant CD11c-expressing immune cells in the plaque by CyTOF and immunohistochemistry. Interferon regulatory factor-5 immunopositive areas were predominantly found within CD11c+ areas with a predilection for the shoulder region, the area of the human plaque most prone to rupture. Accordingly, an inducible plaque rupture model of ApoE-/-Irf5-/- mice had significantly lower frequencies of carotid plaque ruptures, smaller necrotic cores, and less CD11c+ macrophages than their IRF5-competent counterparts.

CONCLUSION

Using complementary evidence from data from human carotid endarterectomies and a murine model of inducible rupture of carotid artery plaque in IRF5-deficient mice, we demonstrate a mechanistic link between the pro-inflammatory transcription factor IRF5, macrophage phenotype, plaque inflammation, and its vulnerability to rupture.

Downregulation of Erythrocyte miR-210 Induces Endothelial Dysfunction in Type 2 Diabetes

Red blood cells (RBC) act as mediators of vascular injury in type 2 diabetes mellitus (T2DM). miR-210 plays a protective role in cardiovascular homeostasis and is decreased in whole blood of T2DM mice. We hypothesized that downregulation of RBC miR-210 induces endothelial dysfunction in T2DM. RBC were coincubated with arteries and endothelial cells ex vivo and transfused in vivo to identify the role of miR-210 and its target protein tyrosine phosphatase 1B (PTP1B) in endothelial dysfunction. RBC from patients with T2DM and diabetic rodents induced endothelial dysfunction ex vivo and in vivo. miR-210 levels were lower in human RBC from patients with T2DM (T2DM RBC) than in RBC from healthy subjects. Transfection of miR-210 in human T2DM RBC rescued endothelial function, whereas miR-210 inhibition in healthy subjects RBC or RBC from miR-210 knockout mice impaired endothelial function. Human T2DM RBC decreased miR-210 expression in endothelial cells. miR-210 expression in carotid artery plaques was lower in T2DM patients than in patients without diabetes. Endothelial dysfunction induced by downregulated RBC miR-210 involved PTP1B and reactive oxygen species. miR-210 mimic attenuated endothelial dysfunction induced by RBC via downregulating vascular PTP1B and oxidative stress in diabetic mice in vivo. These data reveal that the downregulation of RBC miR-210 is a novel mechanism driving the development of endothelial dysfunction in T2DM.

Lnc-C2orf63-4-1 Confers VSMC Homeostasis and Prevents Aortic Dissection Formation via STAT3 Interaction

Emerging evidence indicates that long non-coding RNAs (lncRNAs) serve as a critical molecular regulator in various cardiovascular diseases. Here, we aimed to identify and functionally characterize lncRNAs as potential mediators in the development of thoracic aortic dissection (TAD). We identified that a novel lncRNA, lnc-C2orf63-4-1, was lowly expressed in aortic samples of TAD patients and angiotensin II (Ang II)-challenged vascular smooth muscle cells (VSMCs), which was correlated with clinically aortic expansion. Besides, overexpression of lnc-C2orf63-4-1 significantly attenuated Ang II-induced apoptosis, phenotypic switching of VSMCs and degradation of extracellular matrix both in vitro and in vivo. A customized transcription factor array identified that signal transducer and activator of transcription 3 (STAT3) functioned as the main downstream effector. Mechanistically, dual-luciferase report analysis and RNA antisense purification (RAP) assay indicated that lnc-C2orf63-4-1 directly decreased the expression of STAT3, which was depend on the reduced stabilization of STAT3 mRNA. Importantly, up-regulation of STAT3 efficiently reversed the protective role of lnc-C2orf63-4-1 against Ang II-mediated vascular remodeling. Therefore, lnc-C2orf63-4-1 negatively regulated the expression of STAT3 and prevented the development of aortic dissection. Our study revealed that lnc-C2orf63-4-1 played a critical role in vascular homeostasis, and its dysfunction exacerbated Ang II-induced pathological vascular remodeling.

Chitinase 3 like 1 is a regulator of smooth muscle cell physiology and atherosclerotic lesion stability

AIMS

Atherosclerotic cerebrovascular disease underlies the majority of ischaemic strokes and is a major cause of death and disability. While plaque burden is a predictor of adverse outcomes, plaque vulnerability is increasingly recognized as a driver of lesion rupture and risk for clinical events. Defining the molecular regulators of carotid instability could inform the development of new biomarkers and/or translational targets for at-risk individuals.

METHODS AND RESULTS

Using two independent human endarterectomy biobanks, we found that the understudied glycoprotein, chitinase 3 like 1 (CHI3L1), is up-regulated in patients with carotid disease compared to healthy controls. Further, CHI3L1 levels were found to stratify individuals based on symptomatology and histopathological evidence of an unstable fibrous cap. Gain- and loss-of-function studies in cultured human carotid artery smooth muscle cells (SMCs) showed that CHI3L1 prevents a number of maladaptive changes in that cell type, including phenotype switching towards a synthetic and hyperproliferative state. Using two murine models of carotid remodelling and lesion vulnerability, we found that knockdown of Chil1 resulted in larger neointimal lesions comprised by de-differentiated SMCs that failed to invest within and stabilize the fibrous cap. Exploratory mechanistic studies identified alterations in potential downstream regulatory genes, including large tumour suppressor kinase 2 (LATS2), which mediates macrophage marker and inflammatory cytokine expression on SMCs, and may explain how CHI3L1 modulates cellular plasticity.

CONCLUSION

CHI3L1 is up-regulated in humans with carotid artery disease and appears to be a strong mediator of plaque vulnerability. Mechanistic studies suggest this change may be a context-dependent adaptive response meant to maintain vascular SMCs in a differentiated state and to prevent rupture of the fibrous cap. Part of this effect may be mediated through downstream suppression of LATS2. Future studies should determine how these changes occur at the molecular level, and whether this gene can be targeted as a novel translational therapy for subjects at risk of stroke.

Circulating microRNAs in Symptomatic and Asymptomatic Carotid Stenosis

Background: Specific microRNAs (miRs) have been implicated in the pathophysiology of atherosclerosis and may represent interesting diagnostic and therapeutic targets in carotid stenosis. We hypothesized that the levels of specific circulating miRs are altered in patients with symptomatic carotid stenosis (sCS) in comparison to those in patients with asymptomatic carotid stenosis (aCS) planned to undergo carotid endarterectomy (CEA). We also studied whether miR levels are associated with plaque vulnerability and stability over time after CEA.

Methods: Circulating levels of vascular-enriched miR-92a, miR-126, miR-143, miR-145, miR-155, miR-210, miR-221, miR-222, and miR-342-3p were determined in 21 patients with sCS and 23 patients with aCS before CEA and at a 90-day follow-up. Transcranial Doppler ultrasound for detection of microembolic signals (MES) in the ipsilateral middle cerebral artery was performed prior to CEA. Carotid plaques were histologically analyzed.

Results: Mean levels of miRs were not considerably different between groups and were only marginally higher in sCS than aCS concerning miR-92a, miR-210, miR-145, and miR-143 with the best evidence concerning miR-92a. After adjustment for vascular risk factors and statin pre-treatment, the effect sizes remained essentially unchanged. At follow-up, however, these modest differences remained uncorroborated. There were no relevant associations between miR-levels and MES or histological plaque vulnerability features.

Conclusions: This study does not provide evidence for strong associations between specific circulating miRs and symptomatic state in a collective of comprehensively characterized patients with carotid stenosis. Further work is needed to elucidate the role of circulating miRs as targets in advanced carotid atherosclerosis.

Long Noncoding RNA MIAT Controls Advanced Atherosclerotic Lesion Formation and Plaque Destabilization

Supplemental Digital Content is available in the text.

Long noncoding RNAs (lncRNAs) are important regulators of biological processes involved in vascular tissue homeostasis and disease development. The present study assessed the functional contribution of the lncRNA myocardial infarction-associated transcript (MIAT) to atherosclerosis and carotid artery disease.

Targeting non-coding RNAs in unstable atherosclerotic plaques: Mechanism, regulation, possibilities, and limitations

Cardiovascular diseases (CVDs) caused by arteriosclerosis are the leading cause of death and disability worldwide. In the late stages of atherosclerosis, the atherosclerotic plaque gradually expands in the blood vessels, resulting in vascular stenosis. When the unstable plaque ruptures and falls off, it blocks the vessel causing vascular thrombosis, leading to strokes, myocardial infarctions, and a series of other serious diseases that endanger people's lives. Therefore, regulating plaque stability is the main means used to address the high mortality associated with CVDs. The progression of the atherosclerotic plaque is a complex integration of vascular cell apoptosis, lipid metabolism disorders, inflammatory cell infiltration, vascular smooth muscle cell migration, and neovascular infiltration. More recently, emerging evidence has demonstrated that non-coding RNAs (ncRNAs) play a significant role in regulating the pathophysiological process of atherosclerotic plaque formation by affecting the biological functions of the vasculature and its associated cells. The purpose of this paper is to comprehensively review the regulatory mechanisms involved in the susceptibility of atherosclerotic plaque rupture, discuss the limitations of current approaches to treat plaque instability, and highlight the potential clinical value of ncRNAs as novel diagnostic biomarkers and potential therapeutic strategies to improve plaque stability and reduce the risk of major cardiovascular events.

MicroRNA: A mediator of diet-induced cardiovascular protection

Diets containing nutrients such as polyunsaturated fatty acids, polyphenols, or vitamins have been shown to have cardiovascular benefits. Micro (mi)RNAs are fundamental regulators of gene expression and function in the cardiovascular system. Diet-induced cardiovascular benefits are associated with changes in endogenous expression of miRNAs in the cardiovascular system. In addition, emerging studies have shown that miRNAs present in the food can be transported in the circulation to tissues. These exogenous miRNAs may also affect cardiovascular function contributing to the diet-induced benefits. This review discusses the emerging role of both endogenous and exogenous miRNAs as mediators of diet-induced cardiovascular protection. Understanding the mechanisms of diet-mediated actions through modulation of miRNA may provide a potential strategy for new therapies.

Genetics of macrovascular complications in type 2 diabetes

Type 2 diabetes mellitus (T2DM) is a metabolic disorder that currently affects more than 400 million worldwide and is projected to cause 552 million cases by the year 2030. Long-term vascular complications, such as coronary artery disease, myocardial infarction, stroke, are the leading causes of morbidity and mortality among diabetic patients. The recent advances in genome-wide technologies have given a powerful impetus to the study of risk markers for multifactorial diseases. To date, the role of genetic and epigenetic factors in modulating susceptibility to T2DM and its vascular complications is being successfully studied that provides the accumulation of genomic knowledge. In the future, this will provide an opportunity to reveal the pathogenetic pathways in the development of the disease and allow to predict the macrovascular complications in T2DM patients. This review is focused on the evidence of the role of genetic variants and epigenetic changes in the development of macrovascular pathology in diabetic patients.

Therapies Targeted at Non-Coding RNAs in Prevention and Limitation of Myocardial Infarction and Subsequent Cardiac Remodeling-Current Experience and Perspectives

Myocardial infarction is one of the major causes of mortality worldwide and is a main cause of heart failure. This disease appears as a final point of atherosclerotic plaque progression, destabilization, and rupture. As a consequence of cardiomyocytes death during the infarction, the heart undergoes unfavorable cardiac remodeling, which results in its failure. Therefore, therapies aimed to limit the processes of atherosclerotic plaque progression, cardiac damage during the infarction, and subsequent remodeling are urgently warranted. A hopeful therapeutic option for the future medicine is targeting and regulating non-coding RNA (ncRNA), like microRNA, circular RNA (circRNA), or long non-coding RNA (lncRNA). In this review, the approaches targeted at ncRNAs participating in the aforementioned pathophysiological processes involved in myocardial infarction and their outcomes in preclinical studies have been concisely presented.

Virtual Transcriptomics: Noninvasive Phenotyping of Atherosclerosis by Decoding Plaque Biology From Computed Tomography Angiography Imaging

[Figure: see text].

Hypoxia-induced miR-210 modulates the inflammatory response and fibrosis upon acute ischemia

Hypoxia-induced miR-210 is a crucial component of the tissue response to ischemia, stimulating angiogenesis and improving tissue regeneration. Previous analysis of miR-210 impact on the transcriptome in a mouse model of hindlimb ischemia showed that miR-210 regulated not only vascular regeneration functions, but also inflammation. To investigate this event, doxycycline-inducible miR-210 transgenic mice (Tg-210) and anti-miR-210 LNA-oligonucleotides were used. It was found that global miR-210 expression decreased inflammatory cells density and macrophages accumulation in the ischemic tissue. To dissect the underpinning cell mechanisms, Tg-210 mice were used in bone marrow (BM) transplantation experiments and chimeric mice underwent hindlimb ischemia. MiR-210 overexpression in the ischemic tissue was sufficient to increase capillary density and tissue repair, and to reduce inflammation in the presence of Wt-BM infiltrating cells. Conversely, when Tg-210-BM cells migrated in a Wt ischemic tissue, dysfunctional angiogenesis, inflammation, and impaired tissue repair, accompanied by fibrosis were observed. The fibrotic regions were positive for α-SMA, Vimentin, and Collagen V fibrotic markers and for phospho-Smad3, highlighting the activation of TGF-β1 pathway. Identification of Tg-210 cells by in situ hybridization showed that BM-derived cells contributed directly to fibrotic areas, where macrophages co-expressing fibrotic markers were observed. Cell cultures of Tg-210 BM-derived macrophages exhibited a pro-fibrotic phenotype and were enriched with myofibroblast-like cells, which expressed canonical fibrosis markers. Interestingly, inhibitors of TGF-β type-1-receptor completely abrogated this pro-fibrotic phenotype. In conclusion, a context-dependent regulation by miR-210 of the inflammatory response was identified. miR-210 expression in infiltrating macrophages is associated to improved angiogenesis and tissue repair when the ischemic recipient tissue also expresses high levels of miR-210. Conversely, when infiltrating an ischemic tissue with mismatched miR-210 levels, macrophages expressing high miR-210 levels display a pro-fibrotic phenotype, leading to impaired tissue repair, fibrosis, and dysfunctional angiogenesis.

PRDX2 Protects Against Atherosclerosis by Regulating the Phenotype and Function of the Vascular Smooth Muscle Cell

Peroxiredoxin 2 (PRDX2), an inhibitor of reactive oxygen species (ROS), is potentially involved in the progression of atherosclerosis (AS). The aim of this study was to explore the role and mechanism of PRDX2 in AS. The expression of PRDX2 was evaluated in 14 human carotid artery tissues with or without AS. The results showed that the positive reaction of PRDX2 was observed in the carotid artery vascular smooth muscle cells (CAVSMCs). To assess the mechanism by which PRDX2 may function in AS, the CAVSMCs were transfected with pEX4-PRDX2 and si-PRDX2. The catalase, hydrogen peroxide (H₂O₂) scavenger, was used to further confirm that PRDX2-induced inhibitory effects might be mediated through reducing ROS levels. Phenotype alteration and functional testing included transcription testing, immunostaining, and expression studies. The drug of MAPK signaling pathway inhibitors SB203580, SP600125, and PD98059 was used to evaluate the underlying mechanism. In this study, we found that the protein level of PRDX2 and the level of H₂O₂ were higher in the human AS carotid artery tissues than in the normal carotid artery tissues, accompanied with the activation of MAPK signaling pathway. The up-regulation of PRDX2 in the CAVSMCs significantly decreased the expression of ROS, collagen type I (COL I), collagen type III (COL III), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) and inhibited the proliferation, migration, and transformation of the CAVSMCs. The up-regulation of PRDX2 reversed the effect of the CAVSMCs treated with tumor necrosis factor-α (TNF-α). In addition, PRDX2 down-regulation promoted the protein levels of p-p38, p-JNK, and p-ERK, which was confirmed in relevant MAPK inhibitor treatment experiments. Our results suggest a protective role of PRDX2, as a scavenger of ROS, in AS progression through inhibiting the VSMC phenotype alteration and function via MAPK signaling pathway.

Genetic predisposition and bioinformatics analysis of ATP-sensitive potassium channels polymorphisms with the risks of elevated apolipoprotein B serum levels and its related arteriosclerosis cardiovascular disease

Serum concentration of apolipoprotein B (Apo B) is causally associated with arteriosclerosis cardiovascular disease (ASCVD) risk. Whether ATP-sensitive potassium channels (KATP) variants predict the risk of increased Apo B concentration (≥ 80 mg/dL) and related ASCVD remain less clear. We recruited 522 subjects with elevated Apo B concentration (≥ 80 mg/dL) and 522 counterpart subjects (< 80 mg/dL) from South China to assess the associations of KATP variants (rs11046182, rs78148713, rs145456027 and rs147265929) with the risks of increased Apo B serum concentration (≥ 80 mg/dL), carotid artery stenosis (CAS) ≥ 50% and new-onset ischemic stroke (IS). Our results showed that only KATP SNP rs11046182 (GG genotype) was associated with increased risk of Apo B ≥ 80 mg/dL (adjusted OR=2.17, P<0.001) and CAS ≥ 50% (adjusted OR=2.63, P=0.011). After median 50.6-months follow-up, subjects carrying GG genotype of rs11046182 were associated with higher risk of new-onset IS (adjusted HR=2.24, P=0.024). Further, the exosome-derived microRNAs (exo-miRs) expression profile was identified by next-generation sequencing. 41 exo-miRs were significantly differentially expressed under cross-talk status between high Apo B level (≥ 80 mg/dL) and KATP rs11046182. Our study demonstrated that KATP variant rs11046182 was associated with higher risks of elevated serum Apo B levels and its related ASCVD, and the possible mechanism was related to specific exo-miRs expression profile of KATP rs11046182.

The Implications of ncRNAs in the Development of Human Diseases

The mammalian genome comprehends a small minority of genes that encode for proteins (barely 2% of the total genome in humans) and an immense majority of genes that are transcribed into RNA but not encoded for proteins (ncRNAs). These non-coding genes are intimately related to the expression regulation of protein-coding genes. The ncRNAs subtypes differ in their size, so there are long non-coding genes (lncRNAs) and other smaller ones, like microRNAs (miRNAs) and piwi-interacting RNAs (piRNAs). Due to their important role in the maintenance of cellular functioning, any deregulation of the expression profiles of these ncRNAs can dissemble in the development of different types of diseases. Among them, we can highlight some of high incidence in the population, such as cancer, neurodegenerative, or cardiovascular disorders. In addition, thanks to the enormous advances in the field of medical genomics, these same ncRNAs are starting to be used as possible drugs, approved by the FDA, as an effective treatment for diseases.

The Molecular Basis of Predicting Atherosclerotic Cardiovascular Disease Risk

Atherosclerotic cardiovascular disease (ASCVD) proceeds through a series of stages: initiation, progression (or regression), and complications. By integrating known biology regarding molecular signatures of each stage with recent advances in high-dimensional molecular data acquisition platforms (to assay the genome, epigenome, transcriptome, proteome, metabolome, and gut microbiome), snapshots of each phase of atherosclerotic cardiovascular disease development can be captured. In this review, we will summarize emerging approaches for assessment of atherosclerotic cardiovascular disease risk in humans using peripheral blood molecular signatures and molecular imaging approaches. We will then discuss the potential (and challenges) for these snapshots to be integrated into a personalized movie providing dynamic readouts of an individual's atherosclerotic cardiovascular disease risk status throughout the life course.

Interaction Between microRNA and DNA Methylation in Atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory disease accompanied by complex pathological changes, such as endothelial dysfunction, foam cell formation, and vascular smooth muscle cell proliferation. Many approaches, including regulating AS-related gene expression in the transcriptional or post-transcriptional level, contribute to alleviating AS development. The DNA methylation is a crucial epigenetic modification in regulating cell function by silencing the relative gene expression. The microRNA (miRNA) is a type of noncoding RNA that plays an important role in gene post-transcriptional regulation and disease development. The DNA methylation and the miRNA are important epigenetic factors in AS. However, recent studies have found a mutual regulation between these two factors in AS development. In this study, recent insights into the roles of miRNA and DNA methylation and their interaction in the AS progression are reviewed.

MicroRNA-520c-3p targeting of RelA/p65 suppresses atherosclerotic plaque formation

Atherosclerosis is a chronic inflammatory disease, and it's the leading cause of death worldwide. Dysregulation of microRNAs (miRNAs) has been found to be associated with atherosclerosis. miR-520c-3p has been implicated in several types of cancer. However, little is known about the role of miR-520c-3p in atherosclerosis. In this study, we found that miR-520c-3p agomir decreased atherosclerotic plaque size, collagen content, the quantity of PCNA-positive cell and RelA/p65 expression of vascular smooth muscle cells (VSMCs) in the aortic valve of apoE^-/- mice in vivo. The possible mechanisms of the protective effects of miR-520c-3p on atherosclerotic mice were then investigated in VSMCs. in vitro experiments showed that miR-520c-3p expressions were significantly reduced in human aortic vascular smooth muscle cell (HASMCs) treated with platelet-derived growth factor (PDGF-BB). miR-520c-3p mimics repress PDGF-BB-mediated the proliferation, migration and decrease in the percentage of cells in G2/M phase, which was associated with downregulation of RelA/p65. Mechanistically, miRNA pull-down, luciferase reporter and mRNA stability assays confirmed miR-520c-3p mimics was able to directly target 3'-UTR of RelA/p65 mRNA and decreased half-life of RelA/p65 mRNA in HASMCs. Overexpression of RelA/p65 reversed the inhibition of cell proliferation induced by miR-520c-3p mimics in HASMCs. In conclusion, our findings suggest that miR-520c-3p inhibits PDGF-BB-mediated the proliferation and migration of HASMCs by targeting RelA/p65, which may provide potential therapeutic strategies in atherosclerosis treatment.

Search for Reliable Circulating Biomarkers to Predict Carotid Plaque Vulnerability

Atherosclerosis is responsible for 20% of ischemic strokes, and the plaques from the internal carotid artery the most frequently involved. Lipoproteins play a key role in carotid atherosclerosis since lipid accumulation contributes to plaque progression and chronic inflammation, both factors leading to plaque vulnerability. Carotid revascularization to prevent future vascular events is reasonable in some patients with high-grade carotid stenosis. However, the degree of stenosis alone is not sufficient to decide upon the best clinical management in some situations. In this context, it is essential to further characterize plaque vulnerability, according to specific characteristics (lipid-rich core, fibrous cap thinning, intraplaque hemorrhage). Although these features can be partly detected by imaging techniques, identifying carotid plaque vulnerability is still challenging. Therefore, the study of circulating biomarkers could provide adjunctive criteria to predict the risk of atherothrombotic stroke. In this regard, several molecules have been found altered, but reliable biomarkers have not been clearly established yet. The current review discusses the concept of vulnerable carotid plaque, and collects existing information about putative circulating biomarkers, being particularly focused on lipid-related and inflammatory molecules.

Liraglutide Increases Serum Levels of MicroRNA-27b, -130a and -210 in Patients with Type 2 Diabetes Mellitus: A Novel Epigenetic Effect

Liraglutide has shown favourable effects on several cardiometabolic risk factors, beyond glucose control. MicroRNAs (miRNAs) regulate gene expression, resulting in post-transcriptional modifications of cell response and function. Specific miRNAs, including miRNA-27b, miRNA-130a, and miRNA-210, play a role in cardiometabolic disease. We aimed to determine the effect of liraglutide on the serum levels of miRNA-27b, miRNA-130a and miRNA-210. Twenty-five subjects with type-2 diabetes mellitus (T2DM), naïve to incretin-based therapy, were treated with liraglutide (1.2 mg/day as an add-on to metformin) for 4 months. miRNAs were quantified using real-time polymerase chain reaction. After liraglutide treatment, we found significant reductions in fasting glucose (from 9.8 ± 5.3 to 6.7 ± 1.6 mmol/L, p = 0.0042), glycosylated haemoglobin (HbA1c) (from 8.1 ± 0.8 to 6.6 ± 1.0%, p = 0.0008), total cholesterol (from 5.0 ± 1.0 to 4.0 ± 0.7 mmol/L, p = 0.0011), triglycerides (from 1.9 ± 1.0 to 1.5 ± 0.8 mmol/L, p = 0.0104) and low-density lipoprotein cholesterol (from 2.9 ± 1.2 to 2.2 ± 0.6 mmol/L, p = 0.0125), while the serum levels of miRNA-27b, miRNA-130a and miRNA-210a were significantly increased (median (interquartile range, IQR) changes: 1.73 (7.12) (p = 0.0401), 1.91 (3.64) (p = 0.0401) and 2.09 (11.0) (p = 0.0486), respectively). Since the changes in miRNAs were independent of changes in all the metabolic parameters investigated, liraglutide seems to exert a direct epigenetic effect in T2DM patients, regulating microRNAs involved in the maintenance of endothelial cell homeostasis. These changes might be implicated in liraglutide’s benefits and may represent useful targets for cardiometabolic management.

MicroRNAs as sentinels and protagonists of carotid artery thromboembolism

Stroke is the leading cause of serious disability in the world and a large number of ischemic strokes are due to thromboembolism from unstable carotid artery atherosclerotic plaque. As it is difficult to predict plaque rupture and surgical treatment of asymptomatic disease carries a risk of stroke, carotid disease continues to present major challenges with regard to clinical decision-making and revascularization. There is therefore an imminent need to better understand the molecular mechanisms governing plaque instability and rupture, as this would allow for the development of biomarkers to identify at-risk asymptomatic carotid plaque prior to disease progression and stroke. Further, it would aid in creation of therapeutics to stabilize carotid plaque. MicroRNAs (miRNAs) have been implicated as key protagonists in various stages of atherosclerotic plaque initiation, development and rupture. Notably, they appear to play a crucial role in carotid artery thromboembolism. As the molecular pathways governing the role of miRNAs are being uncovered, we are learning that their involvement is complex, tissue- and stage-specific, and highly selective. Notably, miRNAs can be packaged and secreted in extracellular vesicles (EVs), where they participate in cell-cell communication. The measurement of EV-encapsulated miRNAs in the circulation may inform disease mechanisms occurring in the plaque itself, and therefore may serve as sentinels of unstable plaque as well as therapeutic targets.

Improved cardiovascular risk prediction in patients with end-stage renal disease on hemodialysis using machine learning modeling and circulating microribonucleic acids

Rationale: To test whether novel biomarkers, such as microribonucleic acids (miRNAs), and nonstandard predictive models, such as decision tree learning, provide useful information for medical decision-making in patients on hemodialysis (HD).

Methods: Samples from patients with end-stage renal disease receiving HD included in the AURORA trial were investigated (n=810). The study included two independent phases: phase I (matched cases and controls, n=410) and phase II (unmatched cases and controls, n=400). The composite endpoint was cardiovascular death, nonfatal myocardial infarction or nonfatal stroke. miRNA quantification was performed using miRNA sequencing and RT-qPCR. The CART algorithm was used to construct regression tree models. A bagging-based procedure was used for validation.

Results: In phase I, miRNA sequencing in a subset of samples (n=20) revealed miR-632 as a candidate (fold change=2.9). miR-632 was associated with the endpoint, even after adjusting for confounding factors (HR from 1.43 to 1.53). These findings were not reproduced in phase II. Regression tree models identified eight patient subgroups with specific risk patterns. miR-186-5p and miR-632 entered the tree by redefining two risk groups: patients older than 64 years and with hsCRP<0.827 mg/L and diabetic patients younger than 64 years. miRNAs improved the discrimination accuracy at the beginning of the follow-up (24 months) compared to the models without miRNAs (integrated AUC [iAUC]=0.71).

Conclusions: The circulating miRNA profile complements conventional risk factors to identify specific cardiovascular risk patterns among patients receiving maintenance HD.

Small Things Matter: Relevance of MicroRNAs in Cardiovascular Disease

MicroRNAs (miRNAs) are short sequences of non-coding RNA that play an important role in the regulation of gene expression and thereby in many physiological and pathological processes. Furthermore, miRNAs are released in the extracellular space, for example in vesicles, and are detectable in various biological fluids, such as serum, plasma, and urine. Over the last years, it has been shown that miRNAs are crucial in the development of several cardiovascular diseases (CVDs). This review discusses the (patho)physiological implications of miRNAs in CVD, ranging from cardiovascular risk factors (i.e., hypertension, diabetes, dyslipidemia), to atherosclerosis, myocardial infarction, and cardiac remodeling. Moreover, the intriguing possibility of their use as disease-specific diagnostic and prognostic biomarkers for human CVDs will be discussed in detail. Finally, as several approaches have been developed to alter miRNA expression and function (i.e., mimics, antagomirs, and target-site blockers), we will highlight the miRNAs with the most promising therapeutic potential that may represent suitable candidates for therapeutic intervention in future translational studies and ultimately in clinical trials. All in all, this review gives a comprehensive overview of the most relevant miRNAs in CVD and discusses their potential use as biomarkers and even therapeutic targets.

Diagnostic value of miR-92a in asymptomatic carotid artery stenosis patients and its ability to predict cerebrovascular events

Background

Early diagnosis of asymptomatic carotid artery stenosis (ACAS) is important to prevent the incidence of cerebrovascular events. This study aimed to investigate the circulating expression of microRNA-92a (miR-92a) in ACAS patients and evaluate its diagnostic value for ACAS and predictive value for cerebrovascular events.

Methods

Circulating expression of miR-92a was measured using quantitative real-time PCR. Chi-square test was used to analyze the association of miR-92a with ACAS patients’ clinical characteristics. A receiver operating characteristic (ROC) was used to evaluate the diagnostic value of miR-92a, and the Kaplan-Meier method and Cox regression analysis were used to assess the predictive value of miR-92a for cerebrovascular events.

Results

Serum expression of miR-92a was higher in ACAS patients than that in the healthy controls (P <  0.001), and associated with patients’ degree of carotid stenosis (P = 0.013). The elevated miR-92a expression could distinguish ACAS patients from healthy individual, and was an independent predictive factor for the occurrence of cerebrovascular events (P = 0.015).

Conclusion

The data from this study indicated that circulating increased miR-92a may serve as a noninvasive diagnostic biomarker for ACAS and a potential risk factor for the future onset of cerebrovascular events.

Oxygen homeostasis and cardiovascular disease: A role for HIF?

Hypoxia, the decline of tissue oxygen stress, plays a role in mediating cellular processes. Cardiovascular disease, relatively widespread with increased mortality, is closely correlated with oxygen homeostasis regulation. Besides, hypoxia-inducible factor-1(HIF-1) is reported to be a crucial component in regulating systemic hypoxia-induced physiological and pathological modifications like oxidative stress, damage, angiogenesis, vascular remodeling, inflammatory reaction, and metabolic remodeling. In addition, HIF1 controls the movement, proliferation, apoptosis, differentiation and activity of numerous core cells, such as cardiomyocytes, endothelial cells (ECs), smooth muscle cells (SMCs), and macrophages. Here we review the molecular regulation of HIF-1 in cardiovascular diseases, intended to improve therapeutic approaches for clinical diagnoses. Better knowledge of the oxygen balance control and the signal mechanisms involved is important to advance the development of hypoxia-related diseases.

Hypoxia-challenged MSC-derived exosomes deliver miR-210 to attenuate post-infarction cardiac apoptosis

BACKGROUND

Myocardial infarction (MI) is a major cause of death worldwide. Although percutaneous coronary intervention and coronary artery bypass grafting can prolong life, cardiac damage persists. In particular, cardiomyocytes have no regenerative capacity. Mesenchymal stem cells (MSCs) are attractive candidates for the treatment of MI. The manner by which MSCs exert a beneficial effect upon injured cells is a source of continued study.

METHODS

After the isolation and identification of exosomes from MSCs, the expression of miR-210 was determined by microarray chip. Subsequently, gain- and loss-function approaches were conducted to detect the role of exosomes and exosomal-miR-210 in cell proliferation and apoptosis of cardiomyocytes, as well as the MI in vivo. Dual-Luciferase Report Gene System was used to demonstrate the target gene of miR-210.

RESULTS

We tested the hypothesis that MSC-derived exosomes transfer specific miRNA to protect cardiomyocytes from apoptotic cell death. Interestingly, direct cardiac injection of MSC exosomes reduced infarct size and improved heart function after coronary ligation. In vitro, the MSC exosomes enhanced cardiomyocyte survival to hypoxia. Confirmation of exosome uptake in myocytes was confirmed. Dual-luciferase reporter assay implicated miR-210 as a mediator of the therapeutic effect and AIFM3 as a downstream target. Treatment with miR-210 overexpressing MSC exosomes improved myocyte protection to both in vitro and in vivo stress. Furthermore, the endogenous and exogenous miR-210 had the same therapeutic effects.

CONCLUSION

These results demonstrated that the beneficial effects offered by MSC-exosomes transplantation after MI are at least partially because of excreted exosome containing mainly miR-210.

Long Range Endocrine Delivery of Circulating miR-210 to Endothelium Promotes Pulmonary Hypertension

RATIONALE

Unproven theories abound regarding the long-range uptake and endocrine activity of extracellular blood-borne microRNAs into tissue. In pulmonary hypertension (PH), microRNA-210 (miR-210) in pulmonary endothelial cells promotes disease, but its activity as an extracellular molecule is incompletely defined.

OBJECTIVE

We investigated whether chronic and endogenous endocrine delivery of extracellular miR-210 to pulmonary vascular endothelial cells promotes PH.

METHODS AND RESULTS

Using miR-210 replete (wild-type [WT]) and knockout mice, we tracked blood-borne miR-210 using bone marrow transplantation and parabiosis (conjoining of circulatory systems). With bone marrow transplantation, circulating miR-210 was derived predominantly from bone marrow. Via parabiosis during chronic hypoxia to induce miR-210 production and PH, miR-210 was undetectable in knockout-knockout mice pairs. However, in plasma and lung endothelium, but not smooth muscle or adventitia, miR-210 was observed in knockout mice of WT-knockout pairs. This was accompanied by downregulation of miR-210 targets ISCU (iron-sulfur assembly proteins)1/2 and COX10 (cytochrome c oxidase assembly protein-10), indicating endothelial import of functional miR-210. Via hemodynamic and histological indices, knockout-knockout pairs were protected from PH, whereas knockout mice in WT-knockout pairs developed PH. In particular, pulmonary vascular engraftment of miR-210-positive interstitial lung macrophages was observed in knockout mice of WT-knockout pairs. To address whether engrafted miR-210-positive myeloid or lymphoid cells contribute to paracrine miR-210 delivery, we studied miR-210 knockout mice parabiosed with miR-210 WT; Cx3cr1 knockout mice (deficient in myeloid recruitment) or miR-210 WT; Rag1 knockout mice (deficient in lymphocytes). In both pairs, miR-210 knockout mice still displayed miR-210 delivery and PH, thus demonstrating a pathogenic endocrine delivery of extracellular miR-210.

CONCLUSIONS

Endogenous blood-borne transport of miR-210 into pulmonary vascular endothelial cells promotes PH, offering fundamental insight into the systemic physiology of microRNA activity. These results also describe a platform for RNA-mediated crosstalk in PH, providing an impetus for developing blood-based miR-210 technologies for diagnosis and therapy in this disease.