Aberrant expression of serum circANRIL and hsa_circ_0123996 in children with Kawasaki disease

Exploring the role of exosomal and non-exosomal non-coding RNAs in Kawasaki disease: Implications for diagnosis and therapeutic strategies against coronary artery aneurysms

Kawasaki disease (KD) is an acute vasculitis primarily affecting children, with a potential risk of developing coronary artery aneurysms (CAAs) and cardiovascular complications. The emergence of non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), has provided insights into Kawasaki disease pathogenesis and opened new avenues for diagnosis and therapeutic intervention. Furthermore, polymorphism analysis of ncRNA genes offers significant insights into genetic predisposition to Kawasaki disease, facilitating tailored treatment approaches and risk assessment to improve patient outcomes. Exosomal ncRNAs, which are ncRNAs encapsulated within extracellular vesicles, have garnered significant attention as potential biomarkers for Kawasaki disease and CAA due to their stability and accessibility in biological fluids. This review comprehensively discusses the biogenesis, components, and potential of exosomal and non-exosomal ncRNAs in Kawasaki disease diagnosis and prognosis prediction. It also highlights the roles of non-exosomal ncRNAs, such as miRNAs, lncRNAs, and circRNAs, in Kawasaki disease pathogenesis and their implications as therapeutic targets. Additionally, the review explores the current diagnostic and therapeutic approaches for Kawasaki disease and emphasizes the need for further research to validate these ncRNA-based biomarkers in diverse populations and clinical settings.

Non-Coding Ribonucleic Acids as Diagnostic and Therapeutic Targets in Cardiac Fibrosis

PURPOSE OF REVIEW

Cardiac fibrosis is a crucial juncture following cardiac injury and a precursor for many clinical heart disease manifestations. Epigenetic modulators, particularly non-coding RNAs (ncRNAs), are gaining prominence as diagnostic and therapeutic tools.

RECENT FINDINGS

miRNAs are short linear RNA molecules involved in post-transcriptional regulation; lncRNAs and circRNAs are RNA sequences greater than 200 nucleotides that also play roles in regulating gene expression through a variety of mechanisms including miRNA sponging, direct interaction with mRNA, providing protein scaffolding, and encoding their own products. NcRNAs have the capacity to regulate one another and form sophisticated regulatory networks. The individual roles and disease relevance of miRNAs, lncRNAs, and circRNAs to cardiac fibrosis have been increasingly well described, though the complexity of their interrelationships, regulatory dynamics, and context-specific roles needs further elucidation. This review provides an overview of select ncRNAs relevant in cardiac fibrosis as a surrogate for many cardiac disease states with a focus on crosstalk and regulatory networks, variable actions among different disease states, and the clinical implications thereof. Further, the clinical feasibility of diagnostic and therapeutic applications as well as the strategies underway to advance ncRNA theranostics is explored.

Role of non-coding RNAs and exosomal non-coding RNAs in vasculitis: A narrative review

A category of very uncommon systemic inflammatory blood vessel illnesses known as vasculitides. The pathogenesis and etiology of vasculitis are still poorly known. Despite all of the progress made in understanding the genetics and causes behind vasculitis, there is still more to learn. Epigenetic dysregulation is a significant contributor to immune-mediated illnesses, and epigenetic aberrancies in vasculitis are becoming more widely acknowledged. Less than 2 % of the genome contains protein-encoding DNA. Studies have shown that a variety of RNAs originating from the non-coding genome exist. Long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) have attracted the most attention in recent years as they are becoming more and more important regulators of different biological processes, such as diseases of the veins. Extracellular vehicles (EVs) such as exosomes, are membrane-bound vesicular structures that break free either during programmed cell death, such as apoptosis, pyroptosis, and necroptosis or during cell activation. Exosomes may be involved in harmful ways in inflammation, procoagulation, autoimmune reactions, endothelial dysfunction/damage, intimal hyperplasia and angiogenesis, all of which may be significant in vasculitis. Herein, we summarized various non-coding RNAs that are involved in vasculitides pathogenesis. Moreover, we highlighted the role of exosomes in vasculitides.

Association of noncoding RNAs with Kawasaki disease: A meta-analysis based on the current evidences

BACKGROUND

In recent years, many studies have focused on the relationship between noncoding RNAs (ncRNAs) and Kawasaki disease (KD). Studies have indicated that ncRNAs are associated with the occurrence and development of KD. Thus, we performed a systematic review and meta-analysis to investigate the diagnostic value of ncRNAs in KD patients.

METHODS

We searched the PubMed, Web of Science, Embase and Cochrane Library, China National Knowledge Infrastructure, VIP, China Biology Medicine disc databases, and Wanfang databases until August 25, 2023 and screened all eligible studies focusing on the diagnostic performance of ncRNAs in KD patients.

RESULTS

In total, 535 articles were found, and 28 articles were included in this systematic review and meta-analysis. The calculated area under the curve value was 0.880 (95% confidence intervals, 0.840-0.900). The pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio were 0.790, 0.830, 4.610, and 0.260, respectively. The pooled diagnostic odds ratio was 17.890 (95% confidence intervals, 13.110-24.420), indicating a relatively good diagnostic performance of the ncRNAs for detecting KD. In addition, the diagnostic value of micro RNAs in KD was better than that of long noncoding RNAs and circular noncoding RNAs. A subgroup analysis by specimen indicated a better diagnostic value of ncRNAs in plasma and platelet than serum. The diagnostic accuracy of ncRNAs was better in febrile controls than in healthy control groups, indicating a relatively good accuracy in distinguishing KD patients from febrile diseases.

CONCLUSIONS

This systematic review and meta-analysis demonstrated that ncRNAs could be used as novel biomarkers for detecting KD. More studies should be conducted in the future to verify the diagnostic values of ncRNAs in KD.

The emerging roles of circRNAs in traits associated with livestock breeding

Many indicators can be used to evaluate the productivity and quality of livestock, such as meat and milk production as well as fat deposition. Meat and milk production are measures of livestock performance, while fat deposition affects the taste and flavor of the meat. The circRNAs, are non-coding RNAs, that are involved in the regulation of all these three traits. We review the functions and mechanisms of circRNAs in muscle and fat development as well as lactation to provide a theoretical basis for circRNA research in animal husbandry. Various phenotypic changes presented in livestock may be produced by different circRNAs. Our current concern is how to use the roles played by circRNAs to our advantage to produce the best possible livestock. Hence, we describe the advantages and disadvantages of knockout techniques for circRNAs. In addition, we also put forward our thoughts regarding the mechanism and network of circRNAs to provide researchers with novel ideas of how molecular biology can help us advance our goals in animal farming. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.

Plasma interleukin-41 serves as a potential diagnostic biomarker for Kawasaki disease

INTRODUCTION

Kawasaki disease (KD) is a systemic vasculitis that causes abnormalities in the coronary arteries. Interleukin (IL)-41 is a novel immunoregulatory cytokine involved in the pathogenesis of some inflammatory and immune-related diseases. However, the role of IL-41 in KD is unclear. The purpose of this study was to detect the expression of IL-41 in the plasma of children with KD and its relationship with the disease.

METHODS

A total of 44 children with KD and 37 healthy controls (HC) were recruited for this study. Plasma concentrations of IL-41 were determined by ELISA. Correlations between plasma IL-41 levels and KD-related clinical parameters were analyzed by Pearson correlation and multivariate linear regression analysis. Receiver operating characteristic curve analysis was used to assess the clinical value of IL-41 in the diagnosis of KD.

RESULTS

Our results showed that plasma IL-41 levels were significantly elevated in children with KD compared with HC. Correlation analysis demonstrated that IL-41 levels were positively correlated with D-dimer and N-terminal pro-B-type natriuretic peptide, and negatively correlated with IgM, mean corpuscular hemoglobin concentration, total protein, albumin and pre-albumin. Multivariable linear regression analysis revealed that IgM and mean corpuscular hemoglobin concentrations were associated with IL-41. Receiver operating characteristic curve analysis showed that the area under the curve of IL-41 was 0.7101, with IL-41 providing 88.64 % sensitivity and 54.05 % specificity.

CONCLUSION

Our study indicated that plasma IL-41 levels in children with KD were significantly higher than those in HC, and may provide a potential diagnostic biomarker for KD.

Involvement of circRNAs in the Development of Heart Failure

In recent years, interest in non-coding RNAs as important physiological regulators has grown significantly. Their participation in the pathophysiology of cardiovascular diseases is extremely important. Circular RNA (circRNA) has been shown to be important in the development of heart failure. CircRNA is a closed circular structure of non-coding RNA fragments. They are formed in the nucleus, from where they are transported to the cytoplasm in a still unclear mechanism. They are mainly located in the cytoplasm or contained in exosomes. CircRNA expression varies according to the type of tissue. In the brain, almost 12% of genes produce circRNA, while in the heart it is only 9%. Recent studies indicate a key role of circRNA in cardiomyocyte hypertrophy, fibrosis, autophagy and apoptosis. CircRNAs act mainly by interacting with miRNAs through a "sponge effect" mechanism. The involvement of circRNA in the development of heart failure leads to the suggestion that they may be promising biomarkers and useful targets in the treatment of cardiovascular diseases. In this review, we will provide a brief introduction to circRNA and up-to-date understanding of their role in the mechanisms leading to the development of heart failure.

The Particular Expression Profiles of Circular RNA in Peripheral Blood of Myocardial Infarction Patients by RNA Sequencing

Myocardial infarction (MI) is one of the most common illnesses seriously harmful to human health. Notwithstanding, the systems of its pathogenesis are as yet not totally demonstrated. CircRNA is one sort of non-coding RNA, and late distributed information proposes that circRNAs assume a significant part in heart diseases; however, their expression profiles in the peripheral blood of patients with MI are not yet totally characterized. Therefore, RNAs from peripheral blood were recruited for high-throughput RNA-seq analysis. A total of 3,862 circRNAs were distinguished to be remarkably different, including 2,738 circRNAs being upregulated and 1,124 circRNAs being downregulated. circTMEM165, circUBAC2, circZNF609, circANKRD12, and circSLC8A1 were reconfirmed by RT-qPCR in the cell model. ROC curves uncovered that they have great sensitivity and specificity in the determination of MI. Besides, circRNAs are associated with cell metabolism and function by directing complex networks among circular RNAs, microRNAs, and messenger RNAs. In outline, our study portrayed the specific articulation profiles of circular RNA in patients with MI. The outcomes showed that circRNAs might fill in as a sort of ideal biomarkers for MI diagnosis. Further exploration of these circRNAs may enrich our understanding of MI etiology and progression.

Efficacy of Glucocorticoid plus Intravenous Immunoglobulin in Children with Immunoglobulin-Insensitive Kawasaki Disease

This study mainly analyzes the clinical effect of glucocorticoid (GC) plus intravenous immunoglobulin (IVIG) in treating children with immunoglobulin (Ig)-insensitive Kawasaki disease (KD). From September 2013 to November 2021, 86 Ig-insensitive KD children were selected, including 46 children (observation group, Obs) treated with GC plus IVIG, and 40 children (control group, Con) treated with IVIG. The symptom (fever and fever) resolution time, inflammatory factors (C-reactive protein, CRP; procalcitonin, PCT; interleukin-6, IL-6), immune indicators (CD3+, CD4+, CD8+ T lymphocytes CD3+, CD4+, and CD4+/CD8+), and incidence of adverse reactions were compared between the groups. The results identified shorter fever and rash resolution time in Obs compared with Con. The posttreatment CRP, PCT, IL-6, and CD8+ and the incidence of adverse events reduced notably in Obs and were lower than Con, while CD3+, CD4+, and CD4+/CD8+ elevated statistically and were higher than that of Con. Our results indicate that GC plus IVIG can significantly promote symptom resolution, alleviate inflammatory response, and improve immune function in children with Ig-insensitivity KD, with favorable safety and clinical promotion value.

Non-coding RNAs in Kawasaki disease: Molecular mechanisms and clinical implications

Kawasaki disease (KD) is an acute self-limiting vasculitis with coronary complications, usually occurring in children. The incidence of KD in children is increasing year by year, mainly in East Asian countries, but relatively stably in Europe and America. Although studies on KD have been reported, the pathogenesis of KD is unknown. With the development of high-throughput sequencing technology, growing number of regulatory noncoding RNAs (ncRNAs) including microRNA (miRNA), long noncoding RNA (lncRNA), and circular RNA (circRNA) have been identified to involved in KD. However, the role of ncRNAs in KD has not been comprehensively elucidated. Therefore, it is significative to study the regulatory role of ncRNA in KD, which might help to uncover new and effective therapeutic strategies for KD. In this review, we summarize recent studies on ncRNA in KD from the perspectives of immune disorders, inflammatory disorders, and endothelial dysfunction, and highlight the potential of ncRNAs as therapeutic targets for KD.

LncRNAs and Cardiovascular Disease

A novel class of RNA molecule emerged from human transcriptome sequencing studies termed long non-coding RNAs. These RNA molecules differ from other classes of non-coding RNAs such as microRNAs in their sizes, sequence motifs and structures. Studies have demonstrated that long non-coding RNAs play a prominent role in the development and progression of cardiovascular disease. They provide the cell with tiered levels of gene regulation interacting with DNA, other RNA molecules or proteins acting in various capacities to control a variety of cellular mechanisms. Cell specificity is a hallmark of lncRNA studies and they have been identified in macrophages, smooth muscle cells, endothelial cells and hepatocytes. Recent lncRNA studies have uncovered functional micropeptides encoded within lncRNA genes that can have a different function to the lncRNA. Disease associated mutations in the genome tend to occur in non-coding regions signifying the importance of non-coding genes in disease associations. There is a great deal of work to be done in the non-coding RNA field and tremendous therapeutic potential due to their cell type specificity. A better understanding of the functions and interactions of lncRNAs will inevitably have clinical implications.

Kawasaki disease: lncRNA Slco4a1 regulates the progression of human umbilical vein endothelial cells by targeting the miR-335-5p/POU5F1 axis

BACKGROUND

Kawasaki disease (KD) is an autoimmune disease with systemic vasculitis as the main pathological change, and is most common in children under 5. The role of long non-coding RNAs (lncRNAs) in human diseases has been highlighted. LncRNA Slco4a1 was reported to promote cell growth and act as an oncogenic regulator in cancer. However, the role of lncRNA Slco4a1 in KD remains unclear. This study aimed to investigate the role and mechanism of lncRNA Slco4a1 in KD.

METHODS

Enzyme linked immunosorbent assay (ELISA), qRT-PCR, Western blot, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining were conducted to explore the function of lncRNA Slco4a1. The interaction between POU5F1 and miR-335-5p was analyzed by the RIP assay and dual luciferase assay.

RESULTS

LncRNA Slco4a1 was significantly upregulated in the serum of KD patients compared with healthy controls. LncRNA Slco4a1 was upregulated in human umbilical vein endothelial cells (HUVECs) stimulated with KD serum. LncRNA Slco4a1 overexpression could promote the expression of inflammatory factors and apoptosis in HUVECs. The number of inflammatory cells and the infiltration area of the coronary artery in KD rats were decreased after lncRNA Slco4a1 silencing. Furthermore, lncRNA Slco4a1 is a sponge of miR-335-5p and negatively regulated the expression of miR-335-5p. POU5F1 was the downstream target of miR-335-5p, and miR-335-5p overexpression could upregulate the expression of POU5F1. Additionally, miR-335-5p overexpression could inhibit the expression of inflammatory factors and apoptosis in HUVECs. We further investigated the effect of lncRNA Slco4a1 on the mitogen-activated protein kinase (MAPK) signaling pathway, and the results showed that lncRNA Slco4a1 could promote the activation of the MAPK signaling pathway.

CONCLUSIONS

Together, these results indicated that lncRNA Slco4a1 could regulate the progression of HUVECs in KD by targeting the miR-335-5p/POU5F1 axis, providing new insights for KD treatment.

Diagnostic value of circRNAs as effective biomarkers in human cardiovascular disease: an updated meta-analysis

Background: A growing body of literature has demonstrated that circular RNAs (circRNAs) are the potential biomarkers in human cardiovascular disease (CVD). Therefore, a meta-analysis based on current studies was accomplished to appraise the role of circRNAs in the diagnostic of CVD patients. Methods: Studies before October 30, 2021, were searched using PubMed, EMBASE, the Web of Science, and Cochrane Library. The diagnostic odds ratio (DOR) with a confidence interval (CI) of 95% was used to investigate the associations between circRNAs and CVDs. Results: A total of 27 eligible articles were selected, including 47 studies, with 6833 participants meeting the criteria standard constrain. The pooled overall sensitivity and specificity for circRNAs expression profile in differentiating CVD patients from controls (non-CVDs or healthy subjects) were 0.81 (95%CI 0.78-0.83) and 0.74 (95%CI 0.68-0.78), respectively; the overall positive likelihood ratio was 3.1 (95%CI 2.5-3.7); the negative likelihood ratio was 0.26 (95%CI 0.22-0.31); the overall diagnostic odds ratio corresponding to an area under the curve of 0.85 (95%CI 0.81-0.88) was 12 (95%CI 9-16). Subgroup analysis indicated that the serum rather than blood has higher diagnostic accuracy. Likewise, meta-regression analysis demonstrated that the specimen, detection method, sample size, and publication year were the main sources of heterogeneity. Sensitivity analysis and Deeks' funnel plot revealed that our results are relatively robust. Conclusions: Our evidence-based analysis results suggested that circRNAs provide higher diagnostic accuracy in the prediction of CVDs. Thus, circRNAs might be potential biomarkers in CVDs.

The Emerging Role of the Interactions between Circular RNAs and RNA-binding Proteins in Common Human Cancers

Circular RNAs (circRNAs) are a unique family of noncoding RNAs that could regulate multiple biological processes, which play a crucial role in carcinogenesis, progression and chemotherapy resistance of cancers. Growing studies have demonstrated that circRNAs act as novel biomarkers and therapeutic targets for cancers by sponging microRNAs (miRNAs). Up to date, another function of circRNAs, combining with RNA-binding proteins (RBPs), was uncovered. However, there is limit studies illustrating the underlying mechanism of circRNAs-RBPs interactions, as well as showing its roles in diverse types of cancers. In this review, we collected the biogenesis, properties of circRNAs, and then synthesize the connection between circRNAs and RBPs, and try to clarify its molecular mechanisms involving in the pathogenesis and progression of several common cancers, aiming to provide a brand-new insight to the prognosis and treatment strategy for cancers.

MicroRNAs and long non-coding RNAs as novel regulators of ribosome biogenesis

Ribosome biogenesis is the fine-tuned, essential process that generates mature ribosomal subunits and ultimately enables all protein synthesis within a cell. Novel regulators of ribosome biogenesis continue to be discovered in higher eukaryotes. While many known regulatory factors are proteins or small nucleolar ribonucleoproteins, microRNAs (miRNAs), and long non-coding RNAs (lncRNAs) are emerging as a novel modulatory layer controlling ribosome production. Here, we summarize work uncovering non-coding RNAs (ncRNAs) as novel regulators of ribosome biogenesis and highlight their links to diseases of defective ribosome biogenesis. It is still unclear how many miRNAs or lncRNAs are involved in phenotypic or pathological disease outcomes caused by impaired ribosome production, as in the ribosomopathies, or by increased ribosome production, as in cancer. In time, we hypothesize that many more ncRNA regulators of ribosome biogenesis will be discovered, which will be followed by an effort to establish connections between disease pathologies and the molecular mechanisms of this additional layer of ribosome biogenesis control.

Circular RNAs in childhood-related diseases and cancers: A review

Research into the diagnosis, treatment and prevention of childhood-related diseases is the key to reducing their morbidity and mortality. Circular RNAs (circRNAs) play critical roles, both in physiology and pathology, and there is ample evidence to show that they play varying roles in tissue development and gene regulation. Studies on circRNAs in different childhood-related diseases have confirmed their great potential for disease prevention and treatment. These breakthroughs highlight the pathological role of circRNAs in cancers, as well as cardiovascular and hereditary childhood illnesses. In this review, we summarize the role of circRNAs in childhood-related diseases and cancer, and provide an update of the possible diagnostic and therapeutic application of circRNAs.

Non-Coding RNA-Driven Regulation of rRNA Biogenesis

Ribosomal RNA (rRNA) biogenesis takes place in the nucleolus, the most prominent condensate of the eukaryotic nucleus. The proper assembly and integrity of the nucleolus reflects the accurate synthesis and processing of rRNAs which in turn, as major components of ribosomes, ensure the uninterrupted flow of the genetic information during translation. Therefore, the abundant production of rRNAs in a precisely functional nucleolus is of outmost importance for the cell viability and requires the concerted action of essential enzymes, associated factors and epigenetic marks. The coordination and regulation of such an elaborate process depends on not only protein factors, but also on numerous regulatory non-coding RNAs (ncRNAs). Herein, we focus on RNA-mediated mechanisms that control the synthesis, processing and modification of rRNAs in mammals. We highlight the significance of regulatory ncRNAs in rRNA biogenesis and the maintenance of the nucleolar morphology, as well as their role in human diseases and as novel druggable molecular targets.

Circ_0123996 promotes cell proliferation and fibrosisin mouse mesangial cells through sponging miR-149-5p and inducing Bach1 expression

Diabetic nephropathy (DN) is a serious microvascular complication of diabetes across the world. Recently, many circular RNAs (circRNAs) can exert a crucial role in DN progression. Our investigation was designed to study whether circ_0123996 was associated with DN and aimed to find out the underlying mechanisms. We observed that circ_0123996 expression was significantly increased in Type 2 diabetes (T2D) with DN in comparison to those patients without DN. Consistently, circ_0123996 was also obviously elevated in DN mice models and high glucose (HG)-incubated MMCs. Then, it was proved transfection of circ_0123996 siRNA in mice mesangial cells (MMCs) restrained MMCs proliferation greatly. In addition, it was demonstrated that decrease of circ_0123996 alleviated fibrosis-related protein expression including FN and Col-4 in MMCs. Next, it was confirmed by our study that circ_0123996 can serve as a sponge for miR-149-5p. miR-149-5p has been identified in several diseases including diabetes. At present, we observed that miR-149-5p was decreased in DN. Overexpression of miR-149-5p greatly repressed the effect of circ_0123996 on MMCs. BTB and CNC homology 1 (Bach1) is reported in various disease including some vascular diseases.Here, Bach1 was confirmed as a target of miR-149-5p. Circ_0123996 upregulated Bach1 expression and restrained MMCs proliferation and fibrosis through sponging miR-149-5p. Thus, it was revealed that circ_0123996 was involved in DN via sponging miR-149-5p and modulating Bach1 expression.

Gene therapy for cardiovascular diseases in China: basic research

Cardiovascular disease has become a major disease affecting health in the whole world. Gene therapy, delivering foreign normal genes into target cells to repair damages caused by defects and abnormal genes, shows broad prospects in treating different kinds of cardiovascular diseases. China has achieved great progress of basic gene therapy researches and pathogenesis of cardiovascular diseases in recent years. This review will summarize the latest research about gene therapy of proteins, epigenetics, including noncoding RNAs and genome-editing technology in myocardial infarction, cardiac ischemia-reperfusion injury, atherosclerosis, muscle atrophy, and so on in China. We wish to highlight some important findings about the essential roles of basic gene therapy in this field, which might be helpful for searching potential therapeutic targets for cardiovascular disease.

Circular RNAs: from biogenesis and function to diseases

OBJECTIVE

Evidence suggests that various diseases may contribute to the circular RNAs (circRNAs) expression disorder. This review was aimed at looking for appropriate biomarkers for the treatment of diseases.

DATA SOURCES

The comprehensive search used online literature databases including PubMed of National Center for Biotechnology Information and Web of Science.

STUDY SELECTION

The study selection was based on the following keywords: circRNAs, biogenesis, biologic function, and disease. The time limit for literature retrieval was from the year 1976 to 2019, with language restriction in English. Relevant articles were carefully reviewed, with no exclusions applied to study design and publication type.

RESULTS

CircRNAs are one of the critical non-coding RNAs (ncRNAs), which are covalently closed continuous loops that do not possess 5' and 3' ends. This makes them resistant to exoribonuclease activity and potentially more stable than their cognate linear transcripts, thus making them ideal candidates for biomarker development. Due to the stable and extensive tissue-specific expression of circRNAs, they can function as microRNA sponges and bind to RNA-binding proteins, regulate transcription and splicing, and translate into proteins to participate in the regulation of physiologic and pathologic processes. Moreover, the expression disorders of circRNAs in diseases, such as neurodegenerative disease, cardiovascular disease, and cancer, make them have potential applications for the diagnosis and treatment of diseases.

CONCLUSIONS

Changes in circRNA expression profiles related to various diseases, and circRNAs often exhibit low expression in cancer tissues. In addition, circRNAs can be detected in patient's body fluids to indicate that circRNAs are effective biomarkers for disease diagnosis. These characteristics make circRNAs have potential applications as novel therapeutic targets for diseases.

Insights into the role of circular RNA in macrophage activation and fibrosis disease

Circular RNAs (circRNAs) are single-stranded RNAs which form a covalent bond structure without a 5' cap or a 3' polyadenylated tail, which is deleted through back-splicing. The expression of circRNAs in highly divergent eukaryotes is abundant. With the development of high-throughput sequencing, the mysteries of circRNAs have gradually been revealed. Increased attention has been paid to determining their biological functions and whether their changed expression profiles are linked to disease progression. Functionally, circRNAs have been shown to act as miRNA sponges or nuclear transcription factor regulators, and to play a part in RNA splicing. Various types of circRNAs have been discovered to be differentially expressed under steady physiological and pathological conditions. Recently, several studies have focused on the roles of circRNAs in macrophages on inflammatory stimulation. In this study, we review the current advances in the understanding of circRNAs in macrophages under various pathological conditions, in particular during organ fibrosis, and summarize possible directions for future circRNA applications.

Aberrant expression of serum circANRIL and hsa_circ_0123996 in children with Kawasaki disease

Background

Kawasaki disease is a childhood systemic vasculitis that causes coronary artery abnormalities. The etiology remains unknown and there are no specific diagnostic tests. Circular non‐coding RNAs are a special class of endogenous RNAs that display some characteristics of an ideal biomarker. However, few studies have examined the expression of circRNAs in the serum of Kawasaki disease (KD) patients. The aim of this study was to identify circRNAs in the serum that can serve as potential biomarkers for KD diagnosis.

Methods

The cases were children diagnosed with KD (n = 56). The controls comprised healthy children (n = 56). Blood was collected from the patients before and after intravenous immunoglobulin therapy, and from the healthy controls. Levels of circANRIL and hsa_circ_0123996 in the serum were measured by quantitative reverse transcription PCR. Then, the potential relationship between serum circRNA levels and patients’ biochemical parameter levels was investigated. Receiver operating characteristic curves were constructed for evaluating the diagnostic value of these circRNAs.

Results

The serum levels of circANRIL were lower in patients with KD before therapy than in the controls, but became higher in the patients after therapy than before therapy. The serum levels of hsa_circ_0123996 were higher in patients with KD before therapy than in healthy controls.

Conclusion

Our study indicated that the circANRIL and hsa_circ_0123996 levels in the serum of patients with KD were significantly different from those in healthy individuals. circANRIL and hsa_circ_0123996 may become potential biomarkers for early KD diagnosis.