Circular RNA expression profile in peripheral blood mononuclear cells from Crohn disease patients

Long noncoding RNAs and circular RNAs as potential diagnostic biomarkers of inflammatory bowel diseases: a systematic review and meta-analysis

Introduction

Inflammatory bowel disease (IBD) poses a growing global burden, necessitating the discovery of reliable biomarkers for early diagnosis. The clinical significance of dysregulated expression of long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) in diagnosing IBD has not been well established. Thus, our study aimed to investigate the diagnostic value of lncRNAs and circRNAs for IBD based on currently available studies.

Methods

A comprehensive search was carried out in diverse electronic databases, such as PubMed, Embase, Scopus, Science Direct and Wiley Online Library to retrieve articles published until October 30, 2023. Stata 17.0 software was employed to determine pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic ratio (DOR), and area under the curve (AUC). Heterogeneity, subgroup analysis, and meta-regression were explored, and publication bias was assessed using Deeks' funnel plot. Fagan's nomogram and likelihood ratio scattergram were employed to evaluate the clinical validity.

Result

A total of 11 articles encompassing 21 studies which involved 1239 IBD patients and 985 healthy controls were investigated. The findings revealed lncRNAs exhibit high level of pooled sensitivity 0.94 (95% CI: 0.87-0.97) and specificity 0.99 (95% CI: 0.89-1.00), along with PLR, NLR, DOR, and AUC values of 64.25 (95% CI: 7.39-558.66), 0.06 (95% CI: 0.03-0.13), 1055.25 (95% CI: 70.61-15770.77), and 0.99 (95% CI: 0.97-0.99), respectively. Conversely, CircRNAs showed moderate accuracy in IBD diagnosis, with sensitivity of 0.68 (95% CI: 0.61-0.73), specificity of 0.73 (95% CI: 0.65-0.79), PLR of 2.47 (95% CI: 1.94-3.16), NLR of 0.45 (95% CI: 0.38-0.53), DOR of 5.54 (95% CI: 3.88-7.93), and AUC value of 0.75 (95% CI: 0.71-0.79). Moreover, findings from subgroup analysis depicted heightened diagnostic efficacy when employing lncRNA H19 and a large sample size (≥100), with notable efficacy in diagnosing both ulcerative colitis (UC) and Crohn's disease (CD).

Conclusion

LncRNAs exhibit high diagnostic accuracy in distinguishing patients with IBD from healthy controls signifying their possible use as potential biomarkers, while circRNAs showed moderate diagnostic accuracy. Nevertheless, to validate our findings and confirm the clinical utility of lncRNAs and circRNAs in IBD diagnosis, a large pool of prospective and multi-center studies should be undertaken.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023491840.

Circular RNAs in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a term encompassing a few chronic inflammatory disorders that leads to damage of the intestinal tract. Although much progress has been made in understanding the pathology of IBD, the precise pathogenesis is not completely understood. Circular RNAs (circRNAs) are single-stranded, covalently closed, endogenous molecules in eukaryotes with a variety of biological functions. CircRNAs have been shown to have regulatory effects in many diseases, such as cancer, cardiovascular disease, and neurological disorders. CircRNAs have also been found to play important roles in IBD, and although they are not sufficiently investigated in the context of IBD, a few circRNAs have been identified as potential biomarkers for the diagnosis and prognosis of IBD and as potential therapeutic targets for IBD. Herein, we survey recent progress in understanding the functions and roles of circRNAs in IBD and discuss their potential clinical applications.

Implications and theragnostic potentials of circular RNAs in rheumatic diseases

Circular RNAs (circRNAs), a class of non-coding RNAs (ncRNAs), are highly stable and ubiquitous molecules that exhibit tissue-specific expression. Accumulating evidence has shown that aberrant expression of circRNAs can play a role in the pathogenesis of several diseases. Rheumatic diseases are a varied group of autoimmune and inflammatory disorders affecting mainly the musculoskeletal system. Notably, circRNAs, which are essential immune system gene modulators, are strongly linked to the occurrence and progression of autoimmune disorders. Here, we present and discuss the current findings concerning the roles, implications and theragnostic potentials of circRNAs in common rheumatic diseases, including ankylosing spondylitis (AS), osteoarthritis (OA), osteoporosis (OP), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), Crohn's disease (CD), and gout. This review aims to provide new insights to support the development of novel diagnostic and therapeutic strategies for these disabling diseases.

Circular RNA_0001187 participates in the regulation of ulcerative colitis development via upregulating myeloid differentiation factor 88

Circular RNA (circRNA) had been confirmed to participate in ulcerative colitis (UC) development. Circular RNA_0001187 (Circ_0001187) had been found to be overexpressed in patients with Crohn disease. Therefore, circ_0001187 might be an important circRNA regulating intestinal inflammatory diseases. However, the role and mechanism of circ_0001187 in UC progression remains unclear. The colonic mucosal tissues were obtained from 23 UC patients and 23 healthy normal controls. Tumor necrosis factor-α (TNF-α) was used to mimic UC cell model in vitro. Cell function was assessed by cell counting kit 8 assay, EdU assay, flow cytometry, ELISA assay and oxidative stress detection. RNA interaction was confirmed by dual-luciferase reporter assay and RIP assay. Serum exosomes were isolated by ultracentrifugation and identified by transmission electron microscope. Circ_0001187 was overexpressed in UC patients. Circ_0001187 knockdown enhanced the proliferation, while suppressed apoptosis, inflammation and oxidative stress of TNF-α-induced FHC cells. Circ_0001187 acted as miR-1236-3p sponge, and the effects of circ_0001187 downregulation on TNF-α-induced FHC cell injury were overturned by miR-1236-3p inhibitor. MYD88 was targeted by miR-1236-3p, and circ_0001187 sponged miR-1236-3p to regulate MYD88. MYD88 knockdown alleviated TNF-α-induced FHC cell injury, and its upregulation revoked the inhibition effect of miR-1236-3p on TNF-α-induced FHC cell injury. High expression of circ_0001187 also was observed in the serum exosomes of UC patients. Our data confirmed that circ_0001187 facilitated UC progression through miR-1236-3p/MYD88 axis, which might be a potential treatment and diagnosis biomarker for UC.

LncRNA-miRNA-mRNA Network Analysis Reveals the Potential Biomarkers in Crohn’s Disease Rats Treated with Herb-Partitioned Moxibustion

Background

Long noncoding RNA (lncRNA) is receiving growing attention in Crohn’s disease (CD). However, the mechanism by which herb-partitioned moxibustion (HPM) regulates the expression and functions of lncRNAs in CD rats is still unclear. The aim of our study is to identify lncRNA-miRNA-mRNA network potential biological functions in CD.

Methods

RNA sequencing and microRNA (miRNA) sequencing were carried out to analyze lncRNA, miRNA and mRNA expression profiles among the CD rats, normal control rats, and CD rats after HPM treatment and constructed the potential related lncRNA-miRNA-mRNA competing endogenous RNA (ceRNA) networks. Then, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, protein–protein interaction (PPI) analysis and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to explore potentially important genes in ceRNA networks.

Results

A total of 189 lncRNAs, 32 miRNAs and 463 mRNAs were determined as differentially expressed (DE) genes in CD rats compared to normal control rats, and 161 lncRNAs, 12 miRNAs and 130 mRNAs were identified as remarkably DE genes in CD rats after HPM treatment compared to CD rats. GO analysis indicated that the target genes were most enriched in cAMP and in KEGG pathway analysis the main pathways included adipocytokine, PPAR, AMPK, FoxO and PI3K-Akt signaling pathway. Finally, qRT-PCR results confirmed that lncRNA LOC102550026 sponged miRNA-34c-5p to regulate the intestinal immune inflammatory response by targeting Pck1.

Conclusion

By constructing a ceRNA network with lncRNA-miRNA-mRNA, PCR verification, and KEGG analysis, we revealed that LOC102550026/miRNA-34c-5p/Pck1 axis and adipocytokine, PPAR, AMPK, FoxO, and PI3K-Akt signaling pathways might regulate the intestinal immune-inflammatory response, and HPM may regulate the lncRNA LOC102550026/miR-34c-5p/Pck1 axis and adipocytokine, PPAR, AMPK, FoxO, and PI3K-Akt signaling pathways, thus improving intestinal inflammation in CD. These findings may be novel potential targets in CD.

New Insights and Advances in Pathogenesis and Treatment of Very Early Onset Inflammatory Bowel Disease

Very early onset inflammatory bowel disease (VEO-IBD) is characterized by multifactorial chronic recurrent intestinal inflammation. Compared with elderly patients, those with VEO-IBD have a more serious condition, not responsive to conventional treatments, with a poor prognosis. Recent studies found that genetic and immunologic abnormalities are closely related to VEO-IBD. Intestinal immune homeostasis monogenic defects (IIHMDs) are changed through various mechanisms. Recent studies have also revealed that abnormalities in genes and immune molecular mechanisms are closely related to VEO-IBD. IIHMDs change through various mechanisms. Epigenetic factors can mediate the interaction between the environment and genome, and genetic factors and immune molecules may be involved in the pathogenesis of the environment and gut microbiota. These discoveries will provide new directions and ideas for the treatment of VEO-IBD.

Hsa_circRNA_103124 Upregulation in Crohn's Disease Promotes Cell Proliferation and Inhibits Autophagy by Regulating the Hsa-miR-650/AKT2 Signaling Pathway

Circular RNAs (circRNAs) play important roles in the pathogenesis of Crohn's disease (CD). We discovered that hsa_circRNA_103124 was upregulated in CD patients in our previous study. Nonetheless, the function of hsa_circRNA_103124 is unclear. In this study, hsa_circRNA_103124 was predicted to interact with hsa-miR-650. Gene Ontology (GO) and pathway analyses identified AKT serine/threonine kinase 2 (AKT2) as the downstream target protein of hsa-miR-650. Activated AKT2 inhibits autophagy, but promotes cell proliferation. Recent studies suggest that the inhibition of autophagy is one of the mechanisms of CD pathogenesis. Therefore, we inferred that hsa_circRNA_103124 might regulate autophagy and proliferation by targeting AKT2 as a sponge for hsa-miR-650. Here, quantitative reverse transcription PCR (RT-QPCR) results revealed that upregulated hsa_circRNA_103124 expression in patients with CD was negatively correlated with hsa-miR-650 expression but positively correlated with the white blood cell count and calprotectin levels. TSC complex subunit 1 (TSC1), one of the proteins upstream of autophagy was downregulated in patients with CD. Consisting with the bioinformatics prediction, it was verified that hsa_circRNA_103124 targeted to hsa-miR650 by fluorescence in situ hybridization (FISH) and luciferase reporter assays. A hsa-miR-650 inhibitor reversed the promotion of rapamycin-induced autophagy and the inhibition of cell proliferation by the hsa_circRNA_103124 siRNA. However, hsa-miR-650 mimics reversed the inhibition of rapamycin-induced autophagy and the promotion of cell proliferation through hsa_circRNA_103124 overexpression. These results indicate that hsa_circRNA_103124 upregulation in patients with CD promotes cell proliferation and inhibits autophagy by regulating the hsa-miR-650/AKT2 signaling pathway.

Diagnostic Biomarker Hsa_circ_0126218 and Functioning Prediction in Peripheral Blood Monocular Cells of Female Patients With Major Depressive Disorder

Introduction

Although major depressive diroder (MDD) has brought huge burden and challenges to society globally, effective and accurate diagnoses and treatments remain inadequate. The pathogenesis that for women are more likely to suffer from depression than men needs to be excavated as well. The function of circRNAs in pathological process of depression has not been widely investigated. This study aims to explore potential diagnostic biomarker circRNA of female patients with MDD and to investigate its role in pathogenesis.

Methods

First, an expression profile of circRNAs in the peripheral blood monocular cells of MDD patients and healthy peripherals were established based on high-throughput sequencing analysis. In addition, the top 10 differentially expressed circRNAs were quantified by quantitative real-time PCR to explore diagnostic biomarkers. To further investigate the function of biomarkers in the pathogenesis of MDD, bioinformatics analysis on downstream target genes of the biomarkers was carried out.

Results

There is a mass of dysregulated circRNAs in PBMCs between female MDD patients and healthy controls. Among the top 10 differentially expressed circRNAs, hsa_circ_0126218 is more feasible as a diagnostic biomarker. The expression level of hsa_circ_0126218 displayed upregulation in patients with MDD and the area under the operating characteristic curve of hsa_circ_0126218 was 0.801 (95% CI 0.7226–0.8791, p < 0.0001). To explain the competing endogenous RNA role of hsa_circ_0126218 in the pathogenesis of female MDD, a hsa_circ_0126218-miRNA-mRNA network was established. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses stated that some of the enriched pathways downstream of hsa_circ_0126218 are closely related to MDD. Moreover, we established a protein-protein network to further screen out the hub genes (PIK3CA, PTEN, MAPK1, CDC42, Lyn, YES1, EPHB2, SMAD2, STAT1, and ILK). The function of hsa_circ_0126218 was refined by constructing a verified circRNA-predicted miRNA-hub gene subnetwork.

Conclusion

hsa_circ_0126218 can be considered as a new female MDD biomarker, and the pathogenesis of female MDD by the downstream regulation of hsa_circ_0126218 has been predicted. These findings may help further improve the early detection, effective diagnosis, convenient monitoring of complications, precise treatment, and timely recurrence prevention of depression.

Expression profiles of circular RNAs in colon biopsies from Crohn's disease patients by microarray analysis

BACKGROUND

Circular RNAs (circRNAs) are involved in various diseases and serve as biomarkers. The present study aimed to investigate unique expression profiles of circRNAs in colon tissues of Crohn's disease (CD) and search novel biomarkers for the diagnosis.

METHODS

Differentially expressed (DE) circRNAs in biopsies from four CD patients, four ulcerative colitis (UC) patients, and four healthy controls (HC) were screened by microarray. Hsa_circ_0062142 and hsa_circ_0001666 were verified in another expanded validation cohort. Bioinformatics analysis was applied to predict the function of two DE circRNAs. Receiver operating characteristic (ROC) curves were constructed to evaluate the diagnostic value of CD.

RESULTS

The top 10 upregulated circRNAs in CD compared with HC were hsa_circ_0000691, hsa_circ_0001666, hsa_circ_0004183, hsa_circ_0009024, hsa_circ RNA_405324, hsa_circ_0002003, hsa_circ_0085323, hsa_circ_0040994, hsa_circ_0062142, and hsa_circ_0048148; the top 10 downregulated circRNAs were hsa_circ_0049356, hsa_circ RNA_405443, hsa_circ RNA_403556, hsa_circ_0092328, hsa_circ_0003979, hsa_circ_0074491, hsa_circ_0023461, hsa_circ RNA_406237, hsa_circ_0034044, and hsa_circ RNA_400564 (fold change in descending order). The expression levels of hsa_circ_0001666 and hsa_circ_0062142 in CD were significantly higher than those in UC and HC (p < 0.01). ROC curves suggested the favorable diagnostic value of hsa_circ_0062142 and hsa_circ_0001666 (AUC = 0.803 and 0.858, respectively, p < 0.01). In silico analysis indicated that these circRNAs may be involved in the progress of CD.

CONCLUSION

Hsa_circ_0062142 and hsa_circ_0001666 may play critical roles in the pathogenesis and serve as potential biomarkers of CD.

CircRNAs as promising biomarkers of inflammatory bowel disease and its associated-colorectal cancer

In recent years, research on the pathogenesis of inflammatory bowel disease (IBD) and its associated-colorectal cancer has been well documented to involve environmental, genetic, immune, and intestinal microbiota factors. Evidence indicates that, regardless of the current high global incidence of IBD with over 3.5 million cases in Europe and North America only, it continues to emerge in newly industrialized countries across Asia, Middle East, and South America. Individuals with IBD have significant increased risk of gastrointestinal and extra-intestinal malignancies, particularly, colorectal cancer (CRC) and lymphomas. Among the significant areas of exploration in IBD and its associated-CRC is the search for effective and reliable diagnostic and prognostic markers, and treatment targets. To this effect, the role of non-coding RNAs in IBD and its associated-CRC has attracted research attention, among which microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) get more detailed exploration while little is known about circular RNAs (circRNAs). This review focuses on the emerging role of circRNAs in the diagnosis, prognosis, and treatment of IBD and its associated-CRC. It introduces the biogenesis of circRNAs and brings an up-to-date report on those found within IBD and CRC environment, as well as their participation toward the promotion or suppression of the conditions, and their diagnostic potentials.

CircRNA_103765 acts as a proinflammatory factor via sponging miR-30 family in Crohn's disease

Increasing evidence suggests that circular RNAs (circRNAs) play critical roles in various pathophysiological activities. However, the role of circRNAs in inflammatory bowel disease (IBD) remains unclear. Here we report the potential roles of hsa_circRNA_103765 in regulating cell apoptosis induced by TNF-α in Crohn’s disease (CD). We identify that CircRNA_103765 expression was significantly upregulated in peripheral blood mononuclear cells (PBMCs) of patients with active IBD. A positive correlation with TNF-α significantly enhanced circRNA_103765 expression in CD, which was significantly reversed by anti-TNF-α mAb (infliximab) treatment. In vitro experiments showed that TNF-α could induce the expression of circRNA_103765, which was cell apoptosis dependent, while silencing of circRNA_103765 could protect human intestinal epithelial cells (IECs) from TNF-α-induced apoptosis. In addition, circRNA_103765 acted as a molecular sponge to adsorb the miR-30 family and impair the negative regulation of Delta-like ligand 4 (DLL4). Collectively, CircRNA_103765 is a novel important regulator of the pathogenesis of IBD via sponging miR-30 family-mediated DLL4 expression changes. Blockade of circRNA_103765 could serve as a novel approach for the treatment of IBD patients.

Network analysis and transcriptome profiling in peripheral blood mononuclear cells of patients with rheumatoid arthritis

The present study aimed to investigate the differential expression of long non-coding RNAs (lncRNAs) in rheumatoid arthritis (RA). High-throughput gene sequencing technology was used to detect the expression of lncRNA and mRNA in three patients with RA (RA group) and normal controls (NC group). A Bioinformatics analysis was used to assess the effects of differentially expressed mRNAs on signaling pathways and biological functions. The selected dysregulated lncRNAs were verified by reverse transcription-quantitative (RT-q)PCR in the peripheral blood mononuclear cells (PBMCs) of patients with RA and age- and sex-matched controls. A correlation analysis was used to analyze the relationship between lncRNAs and clinical indexes. From the lncRNA sequencing data, significantly differentially expressed lncRNAs between the RA and NC groups were identified by a fold change ≥2 and P<0.05. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis suggested that the differentially expressed mRNAs were mainly involved in organelle composition, intracellular regulation, signaling pathways, cancer, virus and inflammation. A total of four of these lncRNAs were confirmed by RT-qPCR to be significantly differentially expressed (LINC00304, MIR503HG, LINC01504 and FAM95B1). Through the correlation analysis, it was confirmed that there was a strong correlation between these lncRNAs and clinical laboratory indicators and indexes such as course of disease, arthrocele and joint tenderness. Overall, the present results suggested that the expression levels of LINC00304, MIR503HG, LINC01504 and FAM95B1 in PBMCs from patients with RA may serve as potential biomarkers for RA diagnosis, influencing the occurrence and progress of RA.

Diagnostic and Therapeutic Value of Hsa_circ_0002594 for T Helper 2-Mediated Allergic Asthma

INTRODUCTION

Circular RNAs (circRNAs) are an endogenous mircoRNA sponge that could act as potential biomarkers for the diagnosis and treatment of diseases. However, the role of circRNAs in asthma is far from clear.

OBJECTIVE

The aim of this study is to assess the diagnostic and therapeutic value of hsa_circ_0002594 for T helper (Th) 2-mediated allergic asthma.

METHODS

The expression profiles of hsa_circ_0002594 in CD4+ T cells were revealed by circRNA microarray. Hsa_circ_0002594 expression was confirmed via quantitative real-time PCR (qRT-PCR) in asthmatic patients and healthy subjects. Hsa_circ_0002594 levels were compared between subgroups. The clinical diagnostic abilities and therapeutic response of hsa_circ_0002594 were evaluated. The analyses utilized included a student's t test, nonparametric tests, Spearman's rank-order correlation, Fisher's exact test, and the generation of receiver operating characteristic (ROC) curves.

RESULTS

Hsa_circ_0002594 was upregulated and positively correlated with fraction of exhaled nitric oxide while negatively correlated with methacholine dose producing a decrease of 20% from baseline in forced expiratory volume in the first second (PD20) in CD4+ T cells of asthma. Furthermore, hsa_circ_0002594 expression was higher in subgroups with a family history, skin pricking test (SPT)-positive, or Th2-high. The hsa_circ_0002594-high subgroup was more frequently associated with Th2-high biomarker profiles and positive SPT. Hsa_circ_0002594 was decreased after inhaled corticosteroids (ICS) treatment. ROC curve analyses of hsa_circ_0002594 showed high area under the curve values in the presence of ICS or not.

CONCLUSIONS

Our data suggested that hsa_circ_0002594 was upregulated in CD4+ T cells and might have potential value in the diagnosis and treatment of Th2-mediated allergic asthma.

Which long noncoding RNAs and circular RNAs contribute to inflammatory bowel disease?

Inflammatory bowel disease (IBD), a chronic relapsing gastrointestinal inflammatory disease, mainly comprises ulcerative colitis (UC) and Crohn’s disease (CD). Although the mechanisms and pathways of IBD have been widely examined in recent decades, its exact pathogenesis remains unclear. Studies have focused on the discovery of new therapeutic targets and application of precision medicine. Recently, a strong connection between IBD and noncoding RNAs (ncRNAs) has been reported. ncRNAs include microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs). The contributions of lncRNAs and circRNAs in IBD are less well-studied compared with those of miRNAs. However, lncRNAs and circRNAs are likely to drive personalized therapy for IBD. They will enable accurate diagnosis, prognosis, and prediction of therapeutic responses and promote IBD therapy. Herein, we briefly describe the molecular functions of lncRNAs and circRNAs and provide an overview of the current knowledge of the altered expression profiles of lncRNAs and circRNAs in patients with IBD. Further, we discuss how these RNAs are involved in the nosogenesis of IBD and are emerging as biomarkers.

Hsa_circRNA_102610 upregulation in Crohn’s disease promotes transforming growth factor-β1-induced epithelial-mesenchymal transition via sponging of hsa-miR-130a-3p

BACKGROUND

The incidence of inflammatory bowel disease, a chronic intestinal inflammatory disorder that includes Crohn’s disease (CD) and ulcerative colitis, is rising. Circular RNAs are considered valuable diagnostic biomarkers for CD. Current evidence supports the views that epithelial-mesenchymal transition (EMT) plays an important role in CD pathogenesis, and that hsa-miR-130a-3p can inhibit transforming growth factor-β1 (TGF-β1)-induced EMT. Our previous study revealed that hsa_circRNA_102610 was upregulated in CD patients. Moreover, we predicted an interaction between hsa_circRNA_102610 and hsa-miR-130a-3p. Thus, we hypothesized that hsa_circRNA_102610 may play roles in the proliferation and EMT of intestinal epithelial cells by sponging hsa-miR-130a-3p to participate in the pathogenesis of CD.

AIM

To explore the mechanism of hsa_circRNA_102610 in the pathogenesis of CD.

METHODS

The relative expression levels of hsa_circRNA_102610 and hsa-miR-130a-3p in patients were detected by quantitative reverse transcription-polymerase chain reaction. The proliferation of human intestinal epithelial cells (HIECs) and normal-derived colon mucosa cell line 460 (NCM460) cells was detected by cell counting kit-8, 5-ethynyl-2’-deoxyuridine staining and cell cycle assays following overexpression or downregulation of hsa_circRNA_102610. Cell proliferation assays were performed as described above in a rescue experiment with hsa-miR-130a-3p mimics. The interaction of hsa_circRNA_102610 and hsa-miR-130a-3p was verified by fluorescence in situ hybridization and dual luciferase reporter assays. The relative expression levels of CyclinD1, mothers against decapentaplegic homolog 4 (SMAD4), E-cadherin, N-cadherin and Vimentin were detected by western blotting following hsa_circRNA_102610 overexpression, TGF-β1-induced EMT or hsa-miR-130a-3p mimic transfection (in rescue experiments).

RESULTS

Upregulation of hsa_circRNA_102610 was determined to be positively correlated with elevated fecal calprotectin levels in CD (r = 0.359, P = 0.007) by Pearson correlation analysis. Hsa_circRNA_102610 promoted the proliferation of HIECs and NCM460 cells, while hsa-miR-130a-3p reversed the cell proliferation-promoting effects of hsa_circRNA_102610. Fluorescence in situ hybridization and dual luciferase reporter assays showed that hsa_circRNA_102610 directly bound hsa-miR-130a-3p in NCM460 and 293T cells. An inverse correlation between downregulation of hsa-miR-130a-3p and upregulation of hsa_circRNA_102610 in CD patients was observed (r = -0.290, P = 0.024) by Pearson correlation analysis. Moreover, overexpression of hsa_circRNA_102610 promoted SMAD4 and CyclinD1 protein expression validated by western-blotting. Furthermore, over-expression of hsa_circRNA_102610 promoted TGF-β1 induced EMT in HIECs and NCM460 cells via targeting of hsa-miR-130a-3p, with increased expression of Vimentin and N-cadherin and decreased expression of E-cadherin.

CONCLUSION

Hsa_circRNA_102610 upregulation in CD patients could promote the proliferation and EMT of intestinal epithelial cells via sponging of hsa-miR-130a-3p.

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.

Dissecting the Role of NF-κb Protein Family and Its Regulators in Rheumatoid Arthritis Using Weighted Gene Co-Expression Network

Rheumatoid arthritis (RA) is a chronic synovial autoinflammatory disease that destructs the cartilage and bone, leading to disability. The functional regulation of major immunity-related pathways like nuclear factor kappa B (NF-κB), which is involved in the chronic inflammatory reactions underlying the development of RA, remains to be explored. Therefore, this study has adopted statistical and knowledge-based systemic investigations (like gene correlation, semantic similarity, and topological parameters based on graph theory) to study the gene expression status of NF-κB protein family (NK^PF) and its regulators in synovial tissues to trace the molecular pathways through which these regulators contribute to RA. A complex protein–protein interaction map (PPIM) of 2,742 genes and 37,032 interactions was constructed from differentially expressed genes (p ≤ 0.05). PPIM was further decomposed into a Regulator Allied Protein Interaction Network (RA^PIN) based on the interaction between genes (5 NK^PF, 31 seeds, 131 hubs, and 652 bottlenecks). Pathway network analysis has shown the RA-specific disturbances in the functional connectivity between seed genes (RIPK1, ATG7, TLR4, TNFRSF1A, KPNA1, CFLAR, SNW1, FOSB, PARVA, CX3CL1, and TRPC6) and NK^PF members (RELA, RELB, NFKB2, and REL). Interestingly, these genes are known for their involvement in inflammation and immune system (signaling by interleukins, cytokine signaling in immune system, NOD-like receptor signaling, MAPK signaling, Toll-like receptor signaling, and TNF signaling) pathways connected to RA. This study, for the first time, reports that SNW1, along with other NK regulatory genes, plays an important role in RA pathogenesis and might act as potential biomarker for RA. Additionally, these genes might play important roles in RA pathogenesis, as well as facilitate the development of effective targeted therapies. Our integrative data analysis and network-based methods could accelerate the identification of novel drug targets for RA from high-throughput genomic data.

Increased circulating circular RNA_103516 is a novel biomarker for inflammatory bowel disease in adult patients

BACKGROUND

Increasing evidence demonstrates that by acting as microRNA sponges modulating gene expression at the transcriptional or post-transcriptional level, circular RNAs (circRNAs) participate in the pathogenesis of a variety of diseases and are considered ideal biomarkers of human disease.

AIM

To examine the expression of circRNA_103516 in inflammatory bowel disease (IBD) and its associations with clinical phenotypes and inflammatory cytokines.

METHODS

Peripheral blood mononuclear cells (PBMCs) were obtained from patients with IBD, healthy controls (HCs), and patient controls (PCs). Expression of circRNA_103516 and hsa-miR-19b-1-5p was assessed by quantitative reverse transcription-polymerase chain reaction. Crohn's disease activity index (CDAI), Mayo score, C-reactive protein (CRP) level, and erythrocyte sedimentation rate (ESR) were measured. To assess the inflammatory cytokines tumour necrosis factor α (TNF-α), interferon-γ (IFN-γ), and interleukin-10 (IL-10), blood samples were analysed by flow cytometry.

RESULTS

Ninety Crohn’s disease (CD) and 90 ulcerative colitis (UC) patients, 80 HCs, and 35 PCs were included in the study. CircRNA_103516 was upregulated in CD and UC patients compared with HCs and PCs (P < 0.05). The area under the curve of circRNA_103516 for diagnosing CD and UC was 0.790 and 0.687, respectively. In addition, circRNA_103516 levels were increased in active CD and UC compared with remittent groups (P = 0.027, P = 0.045). Furthermore, in CD, circRNA_103516 correlated positively with CDAI (P < 0.001), CRP (P < 0.001), ESR (P < 0.001), TNF­α (P < 0.001), and IFN-γ (P < 0.001) and negatively correlated with IL-10 (P = 0.006). In UC patients, circRNA_103516 correlated with Mayo score (P < 0.001), CRP (P < 0.001), ESR (P < 0.001), TNF­α (P < 0.001), IFN-γ (P =0.011), and IL-10 (P = 0.002). Additionally, circRNA_103516 correlated positively with stricturing (P = 0.018) and penetrating (P = 0.031) behaviour. Moreover, hsa-miR-19b-1-5p correlated negatively with circRNA_103516 in CD.

CONCLUSION

CircRNA_103516 levels in PBMCs can be considered an ideal candidate biomarker for diagnosing IBD. Dysregulation of circRNA_103516 may participate in the molecular mechanism of IBD through hsa-miR-19b-1-5p sponging.