HDL and microRNA therapeutics in cardiovascular disease

The Role of Circulating MicroRNAs in Cardiovascular Diseases: A Novel Biomarker for Diagnosis and Potential Therapeutic Targets?

MicroRNAs, involved in a large variety of pathological conditions, tend to be potential specific biomarkers in cardiovascular diseases. Moreover, these short, non-coding RNAs, regulate post-transcriptional gene expression and protein synthesis, making them ideal for therapeutic targets. Down-regulation and up-regulation of specific microRNAs are currently studied as a novel approach to the diagnosis and treatment of cardiovascular diseases, such as chronic and acute coronary syndromes, atherosclerosis, heart failure, and arrhythmia. MicroRNAs are interesting and attractive targets for cardiovascular-associated therapeutics because of their stability, tissue-specific expression pattern, and secretion of body fluids. Extended research on their isolation, detection, and function will provide the standardization needed for using microRNAs as biomarkers and potential therapeutic targets. This review will summarize recent data on the implication of microRNAs in cardiovascular diseases, their potential role as biomarkers for diagnosis, and also the challenges of using microRNAs as future therapeutic targets.

Pleiotropic functions and clinical importance of circulating HDL-PON1 complex

High density lipoprotein (HDL) functions are mostly mediated through a complex proteome, particularly its enzymes. HDL can provide a scaffold for the assembly of several proteins that affect each other's function. HDL particles, particularly small, dense HDL3, are rich in paraoxonase 1 (PON1), which is an important enzyme in the functionality of HDL, so the antioxidant and antiatherogenic properties of HDL are largely attributed to this enzyme. There is an increasing need to represent a valid, reproducible, and reliable method to assay HDL function in routine clinical laboratories. In this context, HDL-associated proteins may be key players; notably PON1 activity (its arylesterase activity) may be a proper candidate because its decreased activity can be considered an important risk factor for HDL dysfunctionality. Of note, automated methods have been developed for the measurement of serum PON1 activity that facilitates its assay in large sample numbers. Arylesterase activity is proposed as a preferred activity among the different activities of PON1 for its assay in epidemiological studies. The binding of PON1 to HDL is critical for the maintenance of its activity and it appears apolipoprotein A-I plays an important role in HDL-PON1 interaction as well as in the biochemical and enzymatic properties of PON1. The interrelationships between HDL, PON1, and HDL's other components are complex and incompletely understood. The purpose of this review is to discuss biochemical and clinical evidence considering the interactions of PON1 with HDL and the role of this enzyme as an appropriate biomarker for HDL function as well as a potential therapeutic target.

High-Density Lipoproteins at the Interface between the NLRP3 Inflammasome and Myocardial Infarction

Despite significant therapeutic advancements, morbidity and mortality following myocardial infarction (MI) remain unacceptably high. This clinical challenge is primarily attributed to two significant factors: delayed reperfusion and the myocardial injury resulting from coronary reperfusion. Following reperfusion, there is a rapid intracellular pH shift, disruption of ionic balance, heightened oxidative stress, increased activity of proteolytic enzymes, initiation of inflammatory responses, and activation of several cell death pathways, encompassing apoptosis, necroptosis, and pyroptosis. The inflammatory cell death or pyroptosis encompasses the activation of the intracellular multiprotein complex known as the NLRP3 inflammasome. High-density lipoproteins (HDL) are endogenous particles whose components can either promote or mitigate the activation of the NLRP3 inflammasome. In this comprehensive review, we explore the role of inflammasome activation in the context of MI and provide a detailed analysis of how HDL can modulate this process.

Clinical relevance of circulating non-coding RNAs in metabolic diseases: Emphasis on obesity, diabetes, cardiovascular diseases and metabolic syndrome

Non-coding RNAs (ncRNAs) participate in the regulation of several cellular processes including transcription, RNA processing and genome rearrangement. The aberrant expression of ncRNAs is associated with several pathological conditions. In this review, we focused on recent information to elucidate the role of various regulatory ncRNAs i.e., micro RNAs (miRNAs), circular RNAs (circRNAs) and long-chain non-coding RNAs (lncRNAs), in metabolic diseases, e.g., obesity, diabetes mellitus (DM), cardiovascular diseases (CVD) and metabolic syndrome (MetS). The mechanisms by which ncRNAs participated in disease pathophysiology were also highlighted. miRNAs regulate the expression of genes at transcriptional and translational levels. circRNAs modulate the regulation of gene expression via miRNA sponging activity, interacting with RNA binding protein and polymerase II transcription regulation. lncRNAs regulate the expression of genes by acting as a protein decoy, miRNA sponging, miRNA host gene, binding to miRNA response elements (MRE) and the recruitment of transcriptional element or chromatin modifiers. We examined the role of ncRNAs in the disease pathogenesis and their potential role as molecular markers for diagnosis, prognosis and therapeutic targets. We showed the involvement of ncRNAs in the onset of obesity and its progression to MetS and CVD. miRNA-192, miRNA-122, and miRNA-221 were dysregulated in all these metabolic diseases. Other ncRNAs, implicated in at least three diseases include miRNA-15a, miRNA-26, miRNA-27a, miRNA-320, and miRNA-375. Dysregulation of ncRNAs increased the risk of development of DM and MetS and its progression to CVD in obese individuals. Hence, these molecules are potential targets to arrest or delay the progression of metabolic diseases.

A Current Update on the Role of HDL-Based Nanomedicine in Targeting Macrophages in Cardiovascular Disease

High-density lipoproteins (HDL) are complex endogenous nanoparticles involved in important functions such as reverse cholesterol transport and immunomodulatory activities, ensuring metabolic homeostasis and vascular health. The ability of HDL to interact with a plethora of immune cells and structural cells places it in the center of numerous disease pathophysiologies. However, inflammatory dysregulation can lead to pathogenic remodeling and post-translational modification of HDL, rendering HDL dysfunctional or even pro-inflammatory. Monocytes and macrophages play a critical role in mediating vascular inflammation, such as in coronary artery disease (CAD). The fact that HDL nanoparticles have potent anti-inflammatory effects on mononuclear phagocytes has opened new avenues for the development of nanotherapeutics to restore vascular integrity. HDL infusion therapies are being developed to improve the physiological functions of HDL and to quantitatively restore or increase the native HDL pool. The components and design of HDL-based nanoparticles have evolved significantly since their initial introduction with highly anticipated results in an ongoing phase III clinical trial in subjects with acute coronary syndrome. The understanding of mechanisms involved in HDL-based synthetic nanotherapeutics is critical to their design, therapeutic potential and effectiveness. In this review, we provide a current update on HDL-ApoA-I mimetic nanotherapeutics, highlighting the scope of treating vascular diseases by targeting monocytes and macrophages.

The Importance of Using Exosome-Loaded miRNA for the Treatment of Spinal Cord Injury

Spinal cord injury (SCI) is a major traumatic disease of the central nervous system characterized by high rates of disability and mortality. Many studies have shown that SCI can be divided into the two stages of primary and secondary injury. Primary injury leads to pathophysiological changes, while consequential injury is even more fatal, including a series of harmful reactions that expand the scope and degree of SCI. Because the pathological process of SCI is highly complex, there is still no clear and effective clinical treatment strategy. Exosomes, membrane-bound extracellular vesicles (EVs) with a diameter of 30-200 nm, have emerged as an ideal vector to deliver therapeutic molecules. At the same time, increasing numbers of studies have shown that miRNAs play a momentous role in the process of SCI. In recent studies, researchers have adopted exosomes as carriers of miRNAs with potential therapeutic effects in SCI. In this review, we summarize relevant articles describing exosomes as miRNA carriers for SCI, after which we discuss further implications and perspectives of this novel treatment modality.

The Role of microRNA in the Development, Diagnosis, and Treatment of Cardiovascular Disease: Recent Developments

Since their discovery in 1993, microRNAs (miRNAs) have emerged as important regulators of many crucial cellular processes, and their dysregulation have been shown to contribute to multiple pathologic conditions, including cardiovascular disease (CVD). miRNAs have been found to regulate the expression of various genes involved in cardiac development and function and in the development and progression of CVD. Many miRNAs are master regulators fine-tuning the expression of multiple, often interrelated, genes involved in inflammation, apoptosis, fibrosis, senescence, and other processes crucial for the development of different forms of CVD. This article presents a review of recent developments in our understanding of the role of miRNAs in the development of CVD and surveys their potential applicability as therapeutic targets and biomarkers to facilitate CVD diagnosis, prognosis, and treatment. There are currently multiple potential miRNA-based therapeutic agents in different stages of development, which can be grouped into two classes: miRNA mimics (replicating the sequence and activity of their corresponding miRNAs) and antagomiRs (antisense inhibitors of specific miRNAs). However, in spite of promising preliminary data and our ever-increasing knowledge about the mechanisms of action of specific miRNAs, miRNA-based therapeutics and biomarkers have yet to be approved for clinical applications. SIGNIFICANCE STATEMENT: Over the last few years microRNAs have emerged as crucial, specific regulators of the cardiovascular system and in the development of cardiovascular disease, by posttranscriptional regulation of their target genes. The minireview presents the most recent developments in this area of research, including the progress in diagnostic and therapeutic applications of microRNAs. microRNAs seem very promising candidates for biomarkers and therapeutic agents, although some challenges, such as efficient delivery and unwanted effects, need to be resolved.

Capturing the RNA castle: Exploiting MicroRNA inhibition for wound healing

The growing pipelines of RNA-based therapies herald new opportunities to deliver better patient outcomes for complex disorders such as chronic nonhealing wounds associated with diabetes. Members of the microRNA (miRNA) family of small noncoding RNAs have emerged as targets for diverse elements of cutaneous wound repair, and both miRNA enhancement with mimics or inhibition with antisense oligonucleotides represent tractable approaches for miRNA-directed wound healing. In this review, we focus on miRNA inhibition strategies to stimulate skin repair given advances in chemical modifications to enhance the performance of antisense miRNA (anti-miRs). We first explore miRNAs whose inhibition in keratinocytes promotes keratinocyte migration, an essential part of re-epithelialisation during wound repair. We then focus on miRNAs that can be targeted for inhibition in endothelial cells to promote neovascularisation for wound healing in the context of diabetic mouse models. The picture that emerges is that direct comparisons of different anti-miRNAs modifications are required to establish the most translationally viable options in the chronic wound environment, that direct comparisons of the impact of inhibition of different miRNAs are needed to quantify and rank their relative efficacies in promoting wound repair, and that a standardised human ex vivo model of the diabetic wound is needed to reduce reliance on mouse models that do not necessarily enhance mechanistic understanding of miRNA-targeted wound healing.

Pro-inflammatory cytokines and microRNAs in male infertility

Background

Male infertility is a problem that affects 10–15% of men of reproductive age. In particular, gametogenesis is a complex process in which inflammation may play a central role through the secretion of cytokines and the expression of microRNAs. We assessed the potential role of proinflammatory cytokines (TNF-α, IL-6 and IL-1α) and microRNAs (miR-146a-5p, miR-34a-5p and miR-23a-3p) in the seminal plasma of infertile men compared to controls, evaluating their correlation with seminal and biochemical parameters.

Methods and results

Expression of cytokines and microRNAs was analyzed by ELISA and q-PCR. Our data shows that IL-1α was significantly increased in the azoospermic group compared to controls, TNF-α mRNA was more expressed in the oligozoospermic group than controls. There were no significant differences in miRNAs expression among the three groups. The correlations between sperm parameters and inflammatory markers were evaluated, however no significance was highlighted.

Conclusions

The determination of each inflammatory marker separately in the seminal plasma of subfertile men, despite some significant differences, does not have a diagnostic value in male infertility even if an assay of selective pro-inflammatory cytokines and microRNAs in the semen may improve the diagnosis of male infertility.

The Endothelium Is Both a Target and a Barrier of HDL's Protective Functions

The vascular endothelium serves as a barrier between the intravascular and extravascular compartments. High-density lipoproteins (HDL) have two kinds of interactions with this barrier. First, bloodborne HDL must pass the endothelium to access extravascular tissues, for example the arterial wall or the brain, to mediate cholesterol efflux from macrophages and other cells or exert other functions. To complete reverse cholesterol transport, HDL must even pass the endothelium a second time to re-enter circulation via the lymphatics. Transendothelial HDL transport is a regulated process involving scavenger receptor SR-BI, endothelial lipase, and ATP binding cassette transporters A1 and G1. Second, HDL helps to maintain the integrity of the endothelial barrier by (i) promoting junction closure as well as (ii) repair by stimulating the proliferation and migration of endothelial cells and their progenitor cells, and by preventing (iii) loss of glycocalix, (iv) apoptosis, as well as (v) transmigration of inflammatory cells. Additional vasoprotective functions of HDL include (vi) the induction of nitric oxide (NO) production and (vii) the inhibition of reactive oxygen species (ROS) production. These vasoprotective functions are exerted by the interactions of HDL particles with SR-BI as well as specific agonists carried by HDL, notably sphingosine-1-phophate (S1P), with their specific cellular counterparts, e.g., S1P receptors. Various diseases modify the protein and lipid composition and thereby the endothelial functionality of HDL. Thorough understanding of the structure-function relationships underlying the multiple interactions of HDL with endothelial cells is expected to elucidate new targets and strategies for the treatment or prevention of various diseases.

Protection against Glucolipotoxicity by High Density Lipoprotein in Human PANC-1 Hybrid 1.1B4 Pancreatic Beta Cells: The Role of microRNA

High-density lipoproteins provide protection against the damaging effects of glucolipotoxicity in beta cells, a factor which sustains insulin secretion and staves off onset of type 2 diabetes mellitus. This study examines epigenetic changes in small non-coding microRNA sequences induced by high density lipoproteins in a human hybrid beta cell model, and tests the impact of delivery of a single sequence in protecting against glucolipotoxicity. Human PANC-1.1B4 cells were used to establish Bmax and Kd for [³H]cholesterol efflux to high density lipoprotein, and minimum concentrations required to protect cell viability and reduce apoptosis to 30mM glucose and 0.25 mM palmitic acid. Microchip array identified the microRNA signature associated with high density lipoprotein treatment, and one sequence, hsa-miR-21-5p, modulated via delivery of a mimic and inhibitor. The results confirm that low concentrations of high-density lipoprotein can protect against glucolipotoxicity, and report the global microRNA profile associated with this lipoprotein; delivery of miR-21-5p mimic altered gene targets, similar to high density lipoprotein, but could not provide sufficient protection against glucolipotoxicity. We conclude that the complex profile of microRNA changes due to HDL treatment may be difficult to replicate using a single microRNA, findings which may inform current drug strategies focused on this approach.

RNAs on the Go: Extracellular Transfer in Insects with Promising Prospects for Pest Management

RNA-mediated pathways form an important regulatory layer of myriad biological processes. In the last decade, the potential of RNA molecules to contribute to the control of agricultural pests has not been disregarded, specifically via the RNA interference (RNAi) mechanism. In fact, several proofs-of-concept have been made in this scope. Furthermore, a novel research field regarding extracellular RNAs and RNA-based intercellular/interorganismal communication is booming. In this article, we review key discoveries concerning extracellular RNAs in insects, insect RNA-based cell-to-cell communication, and plant-insect transfer of RNA. In addition, we overview the molecular mechanisms implicated in this form of communication and discuss future biotechnological prospects, namely from the insect pest-control perspective.

High-density lipoprotein remodelled in hypercholesterolaemic blood induce epigenetically driven down-regulation of endothelial HIF-1α expression in a preclinical animal model

AIMS

High-density lipoproteins (HDLs) are circulating micelles that transport proteins, lipids, and miRNAs. HDL-transported miRNAs (HDL-miRNAs) have lately received attention but their effects on vascular cells are not fully understood. Additionally, whether cardiovascular risk factors affect HDL-miRNAs levels and miRNA transfer to recipient cells remains equally poorly known. Here, we have investigated the changes induced by hypercholesterolaemia on HDL-miRNA levels and its effect on recipient endothelial cells (ECs).

METHODS AND RESULTS

Pigs were kept on a high-fat diet (HC; n = 10) or a normocholesterolaemic chow (NC; n = 10) for 10 days reaching cholesterol levels of 321.0 (229.7-378.5) mg/dL and 74.0 (62.5-80.2) mg/dL, respectively. HDL particles were isolated, purified, and quantified. HDL-miRNA profiling (n = 149 miRNAs) of HC- and NC-HDLs was performed by multipanel qPCR. Cell cultures of porcine aortic ECs were used to determine whether HDL-miRNAs were delivered to ECs. Potential target genes modulated by miRNAs were identified by bioinformatics and candidate miRNAs were validated by molecular analysis. In vivo effects in the coronary arteries of normocholesterolaemic swine administered HC- or NC-HDLs were analysed. Among the HDL-miRNAs, four were found in different amounts in HC- and NC-HDL (P < 0.05). miR-126-5p and -3p and miR-30b-5p (2.7×, 1.7×, and 1.3×, respectively) were found in higher levels and miR-103a-3p and miR-let-7g-5p (-1.6×, -1.4×, respectively) in lower levels in HC-HDL. miR-126-5p and -3p were transferred from HC-HDL to EC (2.5×; P < 0.05), but not from NC-HDL, by a SRB1-mediated mechanism. Bioinformatics revealed that HIF1α was the miR-126 target gene with the highest predictive value, which was accordingly found to be markedly reduced in HC-HDL-treated ECs and in miR126 mimic transfected ECs. In vivo validation confirmed that HIF1α was diminished in the coronary endothelial layer of NC pigs administered HC-HDL vs. those administered NC-HDL (P < 0.05).

CONCLUSION

Hypercholesterolaemia induces changes in the miRNA content of HDL enhancing miR126 and its delivery to ECs with the consequent down-regulation of its target gene HIF1α.

Physico-chemical and physiological determinants of lipo-nanoparticle stability

Liposome-based nanoparticles (NPs) comprised mostly of phospholipids (PLs) have been developed to deliver diagnostic and therapeutic agents. Whereas reassembled plasma lipoproteins have been tested as NP carriers of hydrophobic molecules, they are unstable because the components can spontaneously transfer to other PL surfaces-cell membranes and lipoproteins-and can be degraded by plasma lipases. Here we review two strategies for NP stabilization. One is to use PLs that contain long acyl-chains: according to a quantitative thermodynamic model and in vivo tests, increasing the chain length of a PL reduces the spontaneous transfer rate and increases plasma lifetime. A second strategy is to substitute ether for ester bonds which makes the PLs lipase resistant. We conclude with recommendations of simple ex vivo and in vitro tests of NP stability that should be conducted before in vivo tests are begun.

The diagnostic value of circulating microRNAs as biomarkers for coronary artery disease: A meta‑analysis

Objective:

In recent years, research on microRNAs (miRNAs) associated with coronary artery disease (CAD) has attracted considerable attention. However, findings of these studies on the validity of circulating miRNAs in CAD diagnosis are controversial. A meta-analysis was therefore conducted to determine the potential value of miRNAs as biomarkers in CAD diagnosis.

Methods:

Relevant documents on miRNAs expression levels in the diagnosis of CAD were searched and collected from Pubmed, Embase, and Web of Science. They were collected from the time of inception of the database till January 31, 2020. A meta-analysis was conducted using Stata14.0 software. Forest maps were studied and a comprehensive evaluation of the diagnostic value of the expression levels of mRNAs in CAD was conducted using statistical indicators such as the summary receiver operating characteristic curve.

Results:

Overall, 14 studies were included, with 38 data sets, involving 29 miRNAs with 846 cases and 898 controls. The meta-analysis revealed that the average sensitivity and specificity of miRNAs for CAD diagnosis were 0.80 (0.75–0.84) and 0.78 (0.75–0.81), respectively. The positive likelihood, negative likelihood, and diagnostic odds ratios were 3.7 (3.1–4.4), 0.26 (0.21–0.33), and 14 (10–21), respectively, and the area under the curve was 0.85 (0.82–0.88). Subgroup analysis revealed that the accuracy in the Asian population was higher than that in the non-Asian population. Multiple miRNAs may be more diagnostically accurate than single miRNAs. MiRNAs in whole blood were more accurate than those in plasma, serum, and peripheral blood mononuclear cells. The diagnostic performance of the quantitative real-time polymerase chain reaction group was better than that of the qPCR group.

Conclusion:

According to our study, miRNAs may be a new, non-invasive diagnostic tool for the diagnosis of CAD. As a screening tool in clinical practice, it has potential diagnostic value and is worthy of clinical promotion. Considering the number and quality of the studies included in this meta-analysis, the above conclusion requires more quality research to verify it.

Apolipoprotein A-I in mouse cerebrospinal fluid derives from the liver and intestine via plasma high-density lipoproteins assembled by ABCA1 and LCAT

Apolipoprotein (apo) A-I, the major structural protein of high-density lipoprotein (HDL), is present in human and mouse cerebrospinal fluid (CSF) despite its lack of expression in brain cells. To identify the origin of apoA-I in CSF, we generated intestine-specific and liver-specific Apoa1 knockout mice (Apoa1^ΔInt and Apoa1^Δliv mice, respectively). Lipoprotein profiles of Apoa1^ΔInt and Apoa1^ΔLiv mice resembled those of control littermates, whereas knockout of Apoa1 in both intestine and liver (Apoa1^ΔIntΔLiv ) resulted in a 60-percent decrease in HDL-cholesterol levels, thus strongly mimicking the Apoa1^-/- mice. Immunoassays revealed that mouse apoA-I was not present in the CSF of the Apoa1^ΔIntΔLiv mice. Furthermore, apoA-I levels in CSF were highly correlated with plasma spherical HDL levels, which were regulated by ABCA1 and LCAT. Collectively, these results suggest that apoA-I protein in CSF originates in liver and small intestine and is taken up from the plasma.

Cardioprotective effects of miR-34a silencing in a rat model of doxorubicin toxicity

Cardiotoxicity remains a serious problem in anthracycline-treated oncologic patients. Therapeutic modulation of microRNA expression is emerging as a cardioprotective approach in several cardiovascular pathologies. MiR-34a increased in animals and patients exposed to anthracyclines and is involved in cardiac repair. In our previous study, we demonstrated beneficial effects of miR-34a silencing in rat cardiac cells exposed to doxorubicin (DOXO). The aim of the present work is to evaluate the potential cardioprotective properties of a specific antimiR-34a (Ant34a) in an experimental model of DOXO-induced cardiotoxicity. Results indicate that in our model systemic administration of Ant34a completely silences miR-34a myocardial expression and importantly attenuates DOXO-induced cardiac dysfunction. Ant34a systemic delivery in DOXO-treated rats triggers an upregulation of prosurvival miR-34a targets Bcl-2 and SIRT1 that mediate a reduction of DOXO-induced cardiac damage represented by myocardial apoptosis, senescence, fibrosis and inflammation. These findings suggest that miR-34a therapeutic inhibition may have clinical relevance to attenuate DOXO-induced toxicity in the heart of oncologic patients.

Roles of Reconstituted High-Density Lipoprotein Nanoparticles in Cardiovascular Disease: A New Paradigm for Drug Discovery

Epidemiological results revealed that there is an inverse correlation between high-density lipoprotein (HDL) cholesterol levels and risks of atherosclerotic cardiovascular disease (ASCVD). Mounting evidence supports that HDLs are atheroprotective, therefore, many therapeutic approaches have been developed to increase HDL cholesterol (HDL-C) levels. Nevertheless, HDL-raising therapies, such as cholesteryl ester transfer protein (CETP) inhibitors, failed to ameliorate cardiovascular outcomes in clinical trials, thereby casting doubt on the treatment of cardiovascular disease (CVD) by increasing HDL-C levels. Therefore, HDL-targeted interventional studies were shifted to increasing the number of HDL particles capable of promoting ATP-binding cassette transporter A1 (ABCA1)-mediated cholesterol efflux. One such approach was the development of reconstituted HDL (rHDL) particles that promote ABCA1-mediated cholesterol efflux from lipid-enriched macrophages. Here, we explore the manipulation of rHDL nanoparticles as a strategy for the treatment of CVD. In addition, we discuss technological capabilities and the challenge of relating preclinical in vivo mice research to clinical studies. Finally, by drawing lessons from developing rHDL nanoparticles, we also incorporate the viabilities and advantages of the development of a molecular imaging probe with HDL nanoparticles when applied to ASCVD, as well as gaps in technology and knowledge required for putting the HDL-targeted therapeutics into full gear.

11PS04 is a new chemical entity identified by microRNA-based biosensing with promising therapeutic potential against cancer stem cells

Phenotypic drug discovery must take advantage of the large amount of clinical data currently available. In this sense, the impact of microRNAs (miRs) on human disease and clinical therapeutic responses is becoming increasingly well documented. Accordingly, it might be possible to use miR-based signatures as phenotypic read-outs of pathological status, for example in cancer. Here, we propose to use the information accumulating regarding the biology of miRs from clinical research in the preclinical arena, adapting it to the use of miR biosensors in the earliest steps of drug screening. Thus, we have used an amperometric dual magnetosensor capable of monitoring a miR-21/miR-205 signature to screen for new drugs that restore these miRs to non-tumorigenic levels in cell models of breast cancer and glioblastoma. In this way we have been able to identify a new chemical entity, 11PS04 ((3aR,7aS)-2-(3-propoxyphenyl)-7,7a-dihydro-3aH-pyrano[3,4-d]oxazol-6(4H)-one), the therapeutic potential of which was suggested in mechanistic assays of disease models, including 3D cell culture (oncospheres) and xenografts. These assays highlighted the potential of this compound to attack cancer stem cells, reducing the growth of breast and glioblastoma tumors in vivo. These data demonstrate the enhanced chain of translatability of this strategy, opening up new perspectives for drug-discovery pipelines and highlighting the potential of miR-based electro-analytical sensors as efficient tools in modern drug discovery.

Artificial High Density Lipoprotein Nanoparticles in Cardiovascular Research

Lipoproteins are endogenous nanoparticles which are the major transporter of fats and cholesterol in the human body. They play a key role in the regulatory mechanisms of cardiovascular events. Lipoproteins can be modified and manipulated to act as drug delivery systems or nanocarriers for contrast agents. In particular, high density lipoproteins (HDL), which are the smallest class of lipoproteins, can be synthetically engineered either as nascent HDL nanodiscs or spherical HDL nanoparticles. Reconstituted HDL (rHDL) particles are formed by self-assembly of various lipids and apolipoprotein AI (apo-AI). A variety of substances including drugs, nucleic acids, signal emitting molecules, or dyes can be loaded, making them efficient nanocarriers for therapeutic applications or medical diagnostics. This review provides an overview about synthesis techniques, physicochemical properties of rHDL nanoparticles, and structural determinants for rHDL function. We discuss recent developments utilizing either apo-AI or apo-AI mimetic peptides for the design of pharmaceutical rHDL formulations. Advantages, limitations, challenges, and prospects for clinical translation are evaluated with a special focus on promising strategies for the treatment and diagnosis of atherosclerosis and cardiovascular diseases.

Dual inhibition of endothelial miR-92a-3p and miR-489-3p reduces renal injury-associated atherosclerosis

BACKGROUND AND AIMS

Cardiovascular disease (CVD) is the leading cause of death in chronic kidney disease (CKD) patients, however, the underlying mechanisms that link CKD and CVD are not fully understood and limited treatment options exist in this high-risk population. microRNAs (miRNA) are critical regulators of gene expression for many biological processes in atherosclerosis, including endothelial dysfunction and inflammation. We hypothesized that renal injury-induced endothelial miRNAs promote atherosclerosis. Here, we demonstrate that dual inhibition of endothelial miRNAs inhibits atherosclerosis in the setting of renal injury.

METHODS

Aortic endothelial miRNAs were analyzed in apolipoprotein E-deficient (Apoe-/-) mice with renal damage (5/6 nephrectomy, 5/6Nx) by real-time PCR. Endothelial miR-92a-3p and miR-489-3p were inhibited by locked-nucleic acid (LNA) miRNA inhibitors complexed to HDL.

RESULTS

Renal injury significantly increased endothelial miR-92a-3p levels in Apoe-/-;5/6Nx mice. Dual inhibition of miR-92a-3p and miR-489-3p in Apoe-/-;5/6Nx with a single injection of HDL + LNA inhibitors significantly reduced atherosclerotic lesion area by 28.6% compared to HDL + LNA scramble (LNA-Scr) controls. To examine the impact of dual LNA treatment on aortic endothelial gene expression, total RNA sequencing was completed, and multiple putative target genes and pathways were identified to be significantly altered, including the STAT3 immune response pathway. Among the differentially expressed genes, Tgfb2 and Fam220a were identified as putative targets of miR-489-3p and miR-92a-3p, respectively. Both Tgfb2 and Fam220a were significantly increased in aortic endothelium after miRNA inhibition in vivo compared to HDL + LNA-Scr controls. Furthermore, Tgfb2 and Fam220a were validated with gene reporter assays as direct targets of miR-489-3p and miR-92a-3p, respectively. In human coronary artery endothelial cells, over-expression and inhibition of miR-92a-3p decreased and increased FAM220A expression, respectively. Moreover, miR-92a-3p overexpression increased STAT3 phosphorylation, likely through direct regulation of FAM220A, a negative regulator of STAT3 phosphorylation.

CONCLUSIONS

These results support endothelial miRNAs as therapeutic targets and dual miRNA inhibition as viable strategy to reduce CKD-associated atherosclerosis.

Circular RNA hsa_circ_0014243 may serve as a diagnostic biomarker for essential hypertension

Circular RNAs (circRNAs) have a great potential as clinical biomarkers; however, specific circRNAs with a diagnostic value for essential hypertension (EH) largely remain to be identified. In the present study, the potential application of Homo sapiens (hsa)_circ_0014243, which was identified to be significantly upregulated in whole blood samples of EH patients in a previous microarray profiling study by our group, in the diagnosis of EH was evaluated. Reverse transcription-quantitative polymerase chain reaction analysis was performed to determine the expression levels of hsa_circ_0014243 and hsa-microRNA (miR)-10a-5p in a total of 178 blood samples collected from 89 healthy controls and 89 patients diagnosed with EH. Divergent primers were designed for circRNAs, while conventional primers were used for miRs. Independent-samples t-tests and bivariate correlation analyses were performed to analyze the association between clinical factors influencing EH and hsa_circ_0014243 expression levels. A receiver operating characteristics (ROC) curve was generated to estimate the diagnostic value of hsa_circ_0014243 for EH. Finally, the expression levels of circRNAs and miRNAs were combined to propose a possible prediction model for EH. The results indicated that hsa_circ_0014243 was upregulated in whole blood samples of EH patients compared with that in the controls (P<0.001). Furthermore, the relative expression levels of hsa_circ_0014243 (Δ quantification cycle) were identified to be significantly correlated with age (r=-0.259, P<0.001), high-density lipoprotein levels (r=0.196, P=0.009) and glucose levels (r=-0.204, P=0.006). The area under the ROC curve (AUC) of the model using hsa_circ_0014243 as a predictor was 0.732. Of note, the AUC increased to 0.781 when hsa_circ_0014243 levels were combined with hsa-miR-10a-5p levels as predictors. The present results suggest that hsa_circ_0014243 has a crucial role in the genesis and development of EH, and presents a certain diagnostic capability for EH.

Platelet-Enriched MicroRNAs and Cardiovascular Homeostasis

SIGNIFICANCE

Platelets are anucleate blood cells that are involved in hemostasis and thrombosis. Although no longer able to generate ribonucleic acid (RNA) de novo, platelets contain messenger RNA (mRNA), YRNA fragments, and premature microRNAs (miRNAs) that they inherit from megakaryocytes. Recent Advances: Novel sequencing techniques have helped identify the unexpectedly large number of RNA species present in platelets. Throughout their life time, platelets can process the pre-existing pool of premature miRNA to give the fully functional miRNA that can regulate platelet protein expression and function.

CRITICAL ISSUES

Platelets make a major contribution to the circulating miRNA pool but platelet activation can have major consequences on Dicer levels and thus miRNA maturation, which has implications for studies that are focused on screening-stored platelets.

FUTURE DIRECTIONS

It will be important to determine the importance of platelets as donors for miRNA-containing microvesicles that can be taken up and processed by other (particularly vascular) cells, thus contributing to homeostasis as well as disease progression. Antioxid. Redox Signal. 29, 902-921.

MicroRNA-23a-5p promotes atherosclerotic plaque progression and vulnerability by repressing ATP-binding cassette transporter A1/G1 in macrophages

Disruption of carotid vulnerable atherosclerotic plaque is responsible for acute ischemic stroke (AIS) and the early detection and intervention approach are greatly limited. Undertaking a microarray of microRNAs (miRNAs) in the plasma of AIS patients with carotid vulnerable plaques, miR-23a-5p was markedly elevated and was positively correlated with the plaque progression and vulnerability. Correspondingly, we found that miR-23a-5p expression was significantly increased in both plasma and macrophages from atherosclerosis mice. Bioinformatics analysis and in vitro knockdown experiments identified that ATP-binding cassette transporter A1/G1 as a novel target of miR-23a-5p. Luciferase reporter assays showed that miR-23a-5p repressed the 3' untranslated regions (UTR) activity of ABCA1/G1. Moreover, functional analyses demonstrated that transfection of miR-23a-5p inhibitor enhanced cholesterol efflux and decreased foam cell formation through upregulating ABCA1/G1 expression levels. Furthermore, long term in vivo systemically delivered miR-23a-5p antagomir significantly increased ABCA1/G1 expression in the aorta of ApoE^-/- mice. Importantly, the miR-23a-5p antagomir therapy significantly reduced atherosclerosis progression and promoted plaque stability. Our observations indicate that miR-23a-5p promotes macrophage-derived foam cell formation and might be a key regulator contributing to atherosclerotic plaque progression and vulnerability.

SLC35E3 identified as a target of novel‑m1061‑5p via microRNA profiling of patients with cardiovascular disease

MicroRNAs (miRNA) are considered to be potential therapeutic targets for the treatment of various cardiovascular diseases (CVDs). To understand the underlying mechanism of miRNAs and target genes associated with CVD, deep sequencing of blood samples from three patients with CVD and three controls was performed using the Illumina HiSeq 2000 system. The results of the present study revealed that 65 abnormal hsa‑miRNAs targeted 2,784 putative genes in patients with CVD; 59 upregulated miRNAs targeted 2,401 genes and six downregulated miRNAs targeted 383 genes. In addition, a total of 49 Gene Ontology (GO) biological processes and were enriched, and the target genes of downregulated miRNAs were enriched in 12 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Most of these pathways are responsible for lipid and glycan metabolism. In particular, three downregulated miRNAs, hsa‑miR‑1268b, hsa‑miR‑1273d, hsa‑miR‑3187‑5p, were involved in a‑linolenic acid metabolism. The target genes of upregulated miRNAs were enriched in 15 KEGG pathways, mainly in the 'neurodegenerative diseases and cancers' class. In the present study five novel upregulated miRNAs, including m0499‑5p, m0970‑5p, m1042‑5p, m1061‑5p and m1953‑5p, and a downregulated miRNA, novel‑m1627‑5p, were identified in patients with CVD. Novel‑m1627‑5p was demonstrated to target 146 human genes. Additionally, Novel‑m1061‑5p targeted four genes, including fumarylacetoacetate hydrolase domain containing 2A, potassium voltage‑gated channel, Shaw‑related subfamily, member 4, coiled‑coil domain containing 85C and solute carrier family 35 member E3 (SLC35E3). The GO term, 'carbohydrate derivative transport involving in biological process', was associated with SLC35E3. Novel‑m1061‑5p in patients with CVD may repress the expression levels of SLC35E3, a member of the nucleoside sugar transporter subfamily E, which is known to cause defective glycol‑conjugation in the Golgi complex and/or the endoplasmic reticulum. Further investigation is required to understand the underlying mechanisms of the novel miRNAs. Novel‑m1061‑5p may serve as a marker for prognosis or a potential target for the treatment of CVD.

Whole blood sequencing reveals circulating microRNA associations with high-risk traits in non-ST-segment elevation acute coronary syndrome

BACKGROUND AND AIMS

Although circulating microRNA (miRNAs) have emerged as biomarkers predicting mortality in acute coronary syndrome (ACS), more data are needed to understand these mechanisms. Mapping miRNAs to high-risk traits may identify miRNAs involved in pathways conferring risk for poor outcome in ACS. We aim to investigate the relationship between circulating miRNAs and high-risk traits in non-ST-segment elevation acute coronary syndrome (NSTE-ACS).

METHODS

Whole-genome miRNA sequencing was performed on RNA extracted from whole blood of 199 patients with NSTE-ACS. Generalized linear models were used to test associations of miRNAs and 13 high-risk clinical traits, including the Global Registry of Acute Coronary Events (GRACE) score, a widely validated risk score for mortality in NSTE-ACS.

RESULTS

There were 205 nominally significant miRNA-risk factor associations (p < 0.05) observed. Significant associations occurred most frequently with chronic heart failure (HF) (43 miRs), GRACE risk score (30 miRs), and renal function (32 miRs). In hierarchical cluster analysis, chronic HF and GRACE risk score clustered most tightly together, sharing 14 miRNAs with matching fold-change direction. Controlling for a false discovery rate of 5%, chronic HF was significantly associated with lower circulating levels of miR-3135b (p < 0.0006), miR-126-5p (p < 0.0001), miR-142-5p (p = 0.0004) and miR-144-5p (p = 0.0007), while increasing GRACE risk score inversely correlated with levels of miR-3135b (p < 0.0001) and positively correlated with levels of miR-28-3p (p = 0.0002).

CONCLUSIONS

Circulating miRs clustered around two powerful traits for mortality risk in NSTE-ACS. MiR-3135b, which was under-expressed in chronic HF and increasing GRACE risk score, and miR-28-3p, which has no known association with cardiovascular disease, warrant further investigation.