Circular RNA Expression Profiles Research Articles

Serum Exosomal Circular RNA Expression Profile and Regulative Role in Proliferative Diabetic Retinopathy.

BackgroundProliferative diabetic retinopathy (PDR), as one of the main microvascular complications of diabetes mellitus, seriously threatens the visual function of the working-age population; yet, the underlying pathogenesis is still poorly understood. This study aimed to identify the distinct exosomal circular RNA (circRNA) expression in PDR serum and preliminarily explore the potential pro-angiogenic mechanism of specific exosomal circRNAs.MethodsWe collected serum samples from 10 patients with PDR and 10 patients with age-matched senile cataract to detect the exosomal differentially expressed genes (DEGs) of circRNAs via high-throughput sequencing, followed by validation with quantitative real-time PCR (qRT-PCR). Next, bioinformatics analyses including competitive endogenous RNA (ceRNA) network, protein–protein interaction network (PPI), and functional enrichment analyses were performed. In addition, the potential function of circFndc3b (hsa_circ_0006156) derived from high-glucose-induced endothelial cells was analyzed in human retinal vascular endothelial cells (HRVECs).ResultsIn total, 26 circRNAs, 106 microRNAs (miRNAs), and 2,264 messenger RNAs (mRNAs) were identified as differentially expressed in PDR serum exosomes compared with cataract serum exosomes (fold change > 1, P < 0.05). A circRNA–miRNA–mRNA ceRNA network was established. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the mRNAs were mainly enriched in the PI3K–Akt signaling pathway, MAPK signaling pathway, Wnt signaling pathway, and VEGF signaling pathway. The PPI network and module analysis identified 10 hub genes, including RhoA, Cdc42, and RASA1. Finally, circFndc3b and exosomes derived from high-glucose-induced endothelial cells were identified with the capability to facilitate angiogenesis in vitro.ConclusionAberrant profiling of exosomal circRNAs in PDR serum was identified. CircFndc3b derived from high-glucose-induced endothelial cells may play an important role in the angiogenesis of PDR.

Analysis of Age-Related Circular RNA Expression Profiles in Mesenchymal Stem Cells of Rat Bone Marrow.

As multicellular organisms age, they undergo a reduction in tissue and organ function. Researchers have put forward a theory that stem cell aging is the main factor responsible for decreased tissue and organ function. The adult stem cells guarantee the maintenance and repair of adult tissues and organs. Among adult stem cells, mesenchymal stem cells (MSCs) are emerging as hopeful candidates for cell-based therapy of numerous diseases. In recent years, high-throughput sequencing technologies have evolved to identify circular RNAs (circRNAs) associated with an increasing number of diseases, such as cancer and age-related diseases. It has been reported that circRNAs can compete with microRNAs (miRNAs) to affect the stability or translation of target RNAs and further regulate gene expression at the transcriptional level. However, the role of circRNAs expressed in MSCs in aging mechanisms has not yet been deciphered. The aim of this study was to explore and analyze the expression profiles of age-related circRNAs in MSCs. In this study, bone marrow MSCs were extracted from aged and young rats and analyzed using high-throughput sequencing and bioinformatics. The reliability of high-throughput RNA sequencing was verified by quantitative real-time polymerase chain reaction. The most important circRNA functions and pathways were further selected by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomics (KEGG) analysis. Age-related circRNAs were found in the circrNA–miRNA–mRNA interaction network. The results of high-throughput sequencing showed that 4,229 circRNAs were involved in age-related senescence of MSCs. Compared with the young group, there were 29 differentially expressed circRNAs in the aged group, of which four were upregulated and 25 were downregulated. GO analysis covered three domains: biological process (BP), cellular component (CC), and molecular function (MF). The terms assigned to the BP domain were cellular metabolic processes and cellular macromolecule metabolic processes. The identified CC terms were intracellular and intracellular part, and the identified MF terms were binding and protein binding. The top five KEGG pathways were mitophagy–animal–Rattus norvegicus, prostate cancer–Rattus norvegicus, pathways in cancer–Rattus norvegicus, lysosome–Rattus norvegicus, and autophagy–animal–Rattus norvegicus. Altogether, circRNAs may play a major role in age-related MSC senescence. This study provides new mechanistic insights into MSC senescence, possibly leading to novel therapeutic strategies for age-related diseases.

Differential Expression and Functional Analysis of CircRNA in the Ovaries of Low and High Fecundity Hanper Sheep.

Simple SummaryLitter size is an important trait affecting reproductive capacity and breeding economics in meat sheep. Consequently, revealing its molecular mechanism helps us understand multiple lambs from the genetic perspective. In this study, we provide a genome-wide expression profile of circular RNAs (circRNAs) expression in Hanper sheep, which is a new breed of meat sheep raised by cross and self-group breeding for 15 years. In this study, ovarian circular RNAs and miRNAs associated with high and low fertility Hanper sheep are identified during the follicular and luteal phases of the estrous cycle, and their potential biological functions are predicted through Gene Ontology (GO), KEGG, GSEA, STEM, WGCNA analysis.Litter size is a considerable quality that determines the production efficiency of mutton sheep. Therefore, revealing the molecular regulation of high and low fertility may aid the breeding process to develop new varieties of mutton sheep. CircRNAs are the important factors regulating follicular development, but their mechanism role in the regulation of litter size in Hanper sheep is not clear. In the present study, ovarian tissues from the follicular (F) or luteal phase (L) of Hanper sheep that were either consecutive monotocous (M) or polytocous were collected. Then, we performed transcriptome sequencing to screen for differentially expressed circRNAs (DE-circRNAs) and elucidate their function. In total, 4256 circRNA derived from 2184 host genes were identified in which 183 (146 were upregulated, while 37 were downregulated) were differentially expressed in monotocous sheep in the follicular phase versus polytocous sheep in the follicular phase (MF vs. PF). Moreover, 34 circRNAs (14 were upregulated, while 20 were downregulated) were differentially expressed in monotocous sheep in the luteal phase versus polytocous sheep in the luteal sheep (ML vs. PL). This was achieved through DE-circRNAs function enrichment annotation analysis by GESA, GO, and KEGG, which function through the EGF-EGFR-RAS-JNK, TGF-β and thyroid hormone signaling pathway to affect the litter size of Hanper sheep in MF vs. PF and ML vs. PL. STEM results showed that MAPK signaling pathways play a key role in MF vs. PF and ML vs. PL. Through WGCNA analysis, AKT3 was a core gene in MF vs. PF and ML vs. PL. Moreover, competitive endogenous RNA (ceRNA) network analysis revealed the target binding sites for miRNA such as oar-miR-27a, oar-miR-16b, oar-miR-200a/b/c, oar-miR-181a, oar-miR-10a/b, and oar-miR-432 in the identified DE-cirRNAs.

Expression profile and bioinformatics analysis of circular RNAs in tongue squamous cell carcinoma.

This study was designed to identify the role of circRNAs in tongue squamous cell carcinoma (TSCC) and discover novel circRNAs as potential diagnostic or therapeutic targets for TSCC. The circRNA expression profiles in TSCC were evaluated by high-throughput sequencing in 6 TSCC patients. Our data showed that 69 circRNAs were downregulated and 208 were upregulated significantly (fold change ≥2.0; p<0.05). GO and KEGG analysis demonstrated that the parental genes of differentially expressed circRNAs were potentially implicated in TSCC pathogenesis. After bioinformatics analysis, 4 circRNAs (hsa_circ_0005035, hsa_circ_0002360, hsa_circ_0066251, and hsa_circ_0003161) were selected and successfully validated by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) in 40 patients and 3 TSCC cell lines. The establishment and analysis of the circRNA-miRNA-mRNA network revealed the potential function and mechanism of these candidate circRNAs. Our study provided a comprehensive circRNAs expression profile of TSCC by RNA-seq and discovered 4 novel circRNAs with potential great diagnostic and therapeutic value. These findings provide new insights into the development of potential biomarkers and targets for TSCC treatment.

Effects of renal denervation on the expression profile of circular RNA in the serum of patients with resistant hypertension

ObjectiveRenal denervation (RDN) is a new treatment option for resistant hypertension (RH), although it has been shown that reduced sympathetic nerve activity after RDN is the main cause of blood pressure decline. In view of the possible correlation between circRNA and hypertension and the metabolic state of the body after RDN, we investigated the potential role of circRNA in RDN treatment of RH. MethodsSerum samples of patients with RH were collected before and 48 h after RDN. We explored the mechanism underlying RDN with high-throughput integration of circRNA data. ResultsThere were 338 circRNAs that were differentiated before and after RDN; 170 were upregulated and 168 were downregulated (≥1.2-fold, P < 0.05), and the expression of five of them changed significantly (≥1.5-fold, P < 0.05). We used reverse transcription-quantitative polymerase chain reaction to confirm these results in 13 other patients with RH. hsa_circRNA_000367 was upregulated and hsa_circRNA_405119 was downregulated after RDN. We predicted their downstream miRNA–mRNA network and analyzed their putative function via the circRNA–miRNA–mRNA pathway. GO/KEGG analysis showed that their functional annotation may be related to nerve injury and hypertension. We used the Venn Diagram Generator to obtain the intersection of predicted target and sympathetic nerve-related genes (from GeneCards website). ConclusionThe mechanism underlying RDN may be closely related to upregulated hsa_circRNA_000367 or downregulated hsa_circRNA_405119 and involve regulated multiple pathways and multiple cellular and molecular biological processes. These circRNAs may potentially be used as treatment effect biomarkers in RDN.

Characteristics of circular RNAs expression of peripheral blood mononuclear cells in humans with coronary artery disease.

Circular RNAs (circRNAs) function as promising biomarkers and therapeutic targets for coronary artery disease due to their high stability, covalently closed structure, and potential gene regulation. We aimed to identify the expression profile and role of circular RNAs (circRNAs) in coronary artery disease (CAD). We performed RNA sequence analysis of circRNAs in peripheral blood mononuclear cells of five patients with CAD and five controls. Bioinformatics analyses were adopted to explore biological functions of differentially expressed circRNAs. The miRanda and TargetScan tools were used to predict the microRNA (miRNA)-targeting interactions and to construct a triple network of differentially expressed gene-circRNA-miRNA-mRNA. In total, 13,160 downregulated and 12,905 upregulated circRNAs were identified in CAD. A gene ontology annotation analysis showed that genes in the network were involved in organelle organization, cell cycle, mitotic cycle, and cellular metabolic process. Parental genes of the 10 dysregulated circRNAs were involved in metabolism and protein modification, and these circRNAs might regulate gene expression associated with CAD via miRNA sponges. As potential competing endogenous RNAs (ceRNAs), dysregulated circRNAs may be involved in the pathogenesis of CAD, which provides new insights into the diagnosis and prognosis of coronary artery disease.

Expression Profiling and Functional Analysis of Circular RNAs in Inner Mongolian Cashmere Goat Hair Follicles.

BackgroundInner Mongolian cashmere goats have hair of excellent quality and high economic value, and the skin hair follicle traits of cashmere goats have a direct and important effect on cashmere yield and quality. Circular RNA has been studied in a variety of tissues and cells.ResultIn this study, high-throughput sequencing was used to obtain the expression profiles of circular RNA (circRNA) in the hair follicles of Inner Mongolian cashmere goats at different embryonic stages (45, 55, 65, and 75 days). A total of 21,784 circRNAs were identified. At the same time, the differentially expressed circRNA in the six comparison groups formed in the four stages were: d75vsd45, 59 upregulated and 33 downregulated DE circRNAs; d75vsd55, 61 upregulated and 102 downregulated DE circRNAs; d75vsd65, 32 upregulated and 33 downregulated DE circRNAs; d65vsd55, 67 upregulated and 169 downregulated DE circRNAs; d65vsd45, 96 upregulated and 63 downregulated DE circRNAs; and d55vsd45, 76 upregulated and 42 downregulated DE circRNAs. Six DE circRNA were randomly selected to verify the reliability of the sequencing results by quantitative RT-PCR. Subsequently, the circRNA corresponding host genes were analyzed by the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. The results showed that the biological processes related to hair follicle growth and development enriched by GO mainly included hair follicle morphogenesis and cell development, and the signaling pathways related to hair follicle development included the Notch signaling pathway and NF-κB signaling pathway. We combined the DE circRNA of d75vsd45 with miRNA and mRNA databases (unpublished) to construct the regulatory network of circRNA–miRNA–mRNA, and formed a total of 102 pairs of circRNA–miRNA and 126 pairs of miRNA–mRNA interactions. The binding relationship of circRNA3236–chi-miR-27b-3p and circRNA3236–chi-miR-16b-3p was further verified by dual-luciferase reporter assays, and the results showed that circRNA3236 and chi-miR-27b-3p, and circRNA3236 and chi-miR-16b-3p have a targeted binding relationship.ConclusionTo summarize, we established the expression profiling of circRNA in the fetal skin hair follicles of cashmere goats, and found that the host gene of circRNA may be involved in the development of hair follicles of cashmere goats. The regulatory network of circRNA–miRNA–mRNA was constructed and preliminarily verified using DE circRNAs.

Expression Profiles of Circular RNAs in Human Papillary Thyroid Carcinoma Based on RNA Deep Sequencing.

BackgroundPapillary thyroid carcinoma (PTC) is the most prevalent type of thyroid cancer. Herein, we purposed to explore the expression patterns of circRNAs in PTC with the overarching goal of improving early diagnosis rates for individuals with PTC.MethodsWe used RNA deep sequencing to determine the expression patterns of circRNAs in PTC. Besides, RT-qPCR was employed to confirm circRNAs. The diagnostic potential of the circRNAs was explored by constructing ROC curves. GO along with KEGG pathway analyses were utilized to elucidate the potential biological roles of differentially expressed circRNAs. Moreover, we predicted cross talks among circRNAs, miRNAs, and mRNAs, followed by establishment of a ceRNA network.ResultsDeep sequencing of four PTC pairs and neighboring nontumor tissues identified 16569 circRNAs, of which, 301 were upregulated and 419 were downregulated. The RT-qPCR data demonstrated that the expression of chr5: 38481299–38530666-, chr2: 159932176–159945082-, chr10: 179994–249088+, chr3: 121378716–121381532+, and chr1: 237423092–237445522+ was downregulated, while the expression of chr4: 25665378–25667298+, chr5: 161330883–161336769-, chr1: 12578718–12579412-, chr7: 116695750–116700284+, and chr7: 116699071–116700284+ was upregulated. The stability test exhibited that circRNAs were more tolerant to temperature, RNase R, and time. On the other hand, ROC curves illustrated that chr4: 25665378–25667298+, chr1: 12578718–12579412-, chr7: 116699071–116700284+, chr7: 116695750–116700284+, chr5: 161330883–161336769-, and chr10: 179994–249088+ were effective as diagnostic indicators. However, a logistic regression model combining the six indicators achieved a better combined prediction index, with 97.7% sensitivity and 95.3% specificity. Moreover, GO along with KEGG pathway analyses illustrated that differentially expressed circRNAs were linked to tumorigenesis. Furthermore, bioinformatics analyses established a promising ceRNAs network among mRNAs, circRNAs, and miRNAs.ConclusionHerein, we demonstrated that several circRNAs are promising PTC diagnostic biomarkers. Further study on the functions and mechanisms of these circRNAs may contribute to the understanding of PTC.

Gene Expression Profiles of Circular RNAs and MicroRNAs in Chronic Rhinosinusitis With Nasal Polyps.

Introduction: Chronic rhinosinusitis (CRS) is often classified primarily on the basis of the absence or presence of nasal polyps (NPs), that is, as CRS with nasal polyps (CRSwNP) or CRS without nasal polyps (CRSsNP). Additionally, according to the percentage of eosinophils, CRSwNP can be further divided into eosinophilic CRSwNP (ECRSwNP) and non-ECRSwNP. CRSwNP is a significant public health problem with a considerable socioeconomic burden. Previous research reported that the pathophysiology of CRSwNP is a complex, multifactorial disease. There have been many studies on its etiology, but its pathogenesis remains unclear. Dysregulated expression of microRNAs (miRNAs) has been shown in psoriasis, rheumatoid arthritis, pulmonary fibrosis, and allergic asthma. Circular RNAs (circRNAs) are also involved in inflammatory diseases such as rheumatoid arthritis, septic acute kidney injury, myocardial ischemia/reperfusion injury, and sepsis-induced liver damage. The function of miRNAs in various diseases, including CRSwNP, is a research hotspot. In contrast, there have been no studies on circRNAs in CRSwNP. Overall, little is known about the functions of circRNAs and miRNAs in CRSwNP. This study aimed to investigate the expression of circRNAs and miRNAs in a CRSwNP group and a control group to determine whether these molecules are related to the occurrence and development of CRSwNP. Methods: Nine nasal mucosa samples were collected, namely, three ECRSwNP samples, three non-ECRSwNP samples, and three control samples, for genomic microarray analysis of circRNA and microRNA expression. All of the tissue samples were from patients who were undergoing functional endoscopic sinus surgery in our department. Then we selected some differentially expressed miRNAs and circRNAs for qPCR verification. Meanwhile, GO enrichment analysis and KEGG pathway analysis were applied to predict the biological functions of aberrantly expressed circRNAs and miRNAs based on the GO and KEGG databases. Receiver operating characteristic (ROC) curve analysis and principal component analysis (PCA) were performed to confirm these molecules are involved in the occurrence and development of CRSwNP. Results: In total, 2,875 circRNAs showed significant differential expression in the CRSwNP group. Specifically, 1794 circRNAs were downregulated and 1,081 circRNAs were upregulated. In the CRSwNP group, the expression of 192 miRNAs was significantly downregulated, and none of the miRNAs were significantly upregulated. GO and KEGG analysis showed differential circRNAs and miRNAs were enriched in “amoebiasis,” “salivary secretion,” “pathways in cancer,” and “endocytosis.” Through qRT-PCR verification, the expression profiles of hsa-circ-0031593, hsa-circ-0031594, hsa-miR-132-3p, hsa-miR-145-5p, hsa-miR-146a-5p, and hsa-miR-27b-3p were shown to have statistical differences. In addition, ROC curve analysis showed that the molecules with the two highest AUCs were hsa-circ-0031593 with AUC 0.8353 and hsa-miR-145-5p with AUC 0.8690. Through PCA with the six ncRNAs, the first principal component explained variance ratio was 98.87%. The AUC of the six ncRNAs was 0.8657. Conclusion: In our study, the expression profiles of ECRSwNP and non-ECRSwNP had no statistical differences. The differentially expressed circRNAs and miRNAs between CRSwNP and control may play important roles in the pathogenesis of CRSwNP. Altered expression of hsa-circ-0031593 and hsa-miR-145-5p have the strongest evidence for involvement in the occurrence and development of CRSwNP because their AUCs are higher than the other molecules tested in this study.

Dynamic Expression Profiles of Circular RNAs during Brown to White Adipose Tissue Transformation in Goats (Capra hircus).

Simple SummaryIn our study, we launched RNA-seq in order to investigate the potential functions of circRNA during brown adipose tissue (BAT) to white adipose tissue (WAT) transformation. As a result, 6610 circRNAs and 61 differentially expressed circRNAs (DEcircRNAs) were identified. Moreover, 65 miRNAs were detected that could potentially interact with DEcircRNAs. The present study provides a detailed circRNA expression landscape and evidence for circRNA functions in the transformation from BAT to WAT.Adipose tissues are mainly divided into brown adipose tissue (BAT) and white adipose tissue (WAT). WAT mainly functions to buffer excess calories, whereas BAT plays a role in the non-shivering thermogenesis to maintain body temperature and energy balance. Moreover, circRNAs play important roles in various biological processes. However, knowledge of the expression profile and function of circRNAs from BAT to WAT remains largely unknown. In this study, a total of 6610 unique circRNAs were identified in the perirenal adipose tissues of 1-day, 30-days, and 1-year goats. Functional annotation revealed that host genes of circRNAs were involved in some BAT-related pathways, such as the thyroid hormone signaling pathway, MAPK signaling pathway, and VEGF signaling pathway. Furthermore, a total of 61 DEcircRNAs were detected across three stages. Additionally, five selected circRNAs were validated by RNase R assay, qPCR, and Sanger sequencing. Finally, the circRNA–miRNA network was constructed between the DEcircRNAs and their miRNA binding sites.

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

BackgroundCircular 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.MethodsDifferentially 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.ResultsThe 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.ConclusionHsa_circ_0062142 and hsa_circ_0001666 may play critical roles in the pathogenesis and serve as potential biomarkers of CD.

Effects of Berberine on Circular RNA Expression Profiles in Human Gastric Cancer Cells.

Background Berberine has been demonstrated to have anticancer effects against gastric cancer (GC), but the mechanism of these actions is unclear. Objectives To explore the impact of berberine on circular RNA (circRNA) expression profiles in GC and investigate the potential molecular mechanisms associated with circRNAs in GC. Methods AGS and HGC27 GC cells were treated with various concentrations of berberine. Cell viability was measured using a Cell Counting Kit-8 assay. Cell proliferation was measured using a cell colony formation assay. Cell apoptosis was measured using flow cytometry. The mitochondrial membrane potential (Δψm) was determined using a JC-1 probe. RNA-seq was performed to identify circRNA expression profiles in AGS cells after berberine treatment. Selected differentially expressed (DE) circRNAs were verified using RT-qPCR. Bioinformatics analysis was performed to predict target miRNAs and mRNAs and construct a circRNA-miRNA-mRNA network. Pathway and process enrichment analyses were performed to explore the potential biological roles of DE circRNAs. Results Berberine decreased GC cell viability, cell proliferation, and Δψm and induced cell apoptosis. Thirty-one DE circRNAs were identified in the berberine-treated group compared to the control group, among which circRNA2499, hsa_circ_0003423, and hsa_circ_0006702 were validated using RT-qPCR. Enrichment analyses, based on the host genes of these 31 DE circRNAs and putative target mRNAs in the circRNA-miRNA-mRNA network of the validated circRNAs, indicated that berberine exerts anti-GC effects in multiple pathways including the Notch, MAPK, and NF-κB signaling pathways via specific circRNAs. Conclusion This study elucidated the expression profile of circRNAs in human GC cells after berberine treatment. Our results demonstrate that berberine has the potential to influence cancer-related pathways by regulating circRNA expression and their corresponding target genes in GC cells.

Expression profile of circular RNAs in oral lichen planus.

This study sought to identify the circular RNAs (circRNAs) differentially expressed in oral lichen planus (OLP) to investigate the possible role of circRNAs in this disease's pathogenesis. Six OLP and six normal oral mucosal tissues were used for circRNA detection and sequencing. 10 selected circRNAs were verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A gene ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to predict the functions of circRNAs in OLP. TargetScan and miRanda were applied to predict targeted micro (mi)RNAs and messenger (m)RNAs of circRNAs, and competing endogenous (ce)RNA networks were mapped. One hundred and thirty-five circRNAs were identified differentially expressed in OLP tissues compared to normal control tissues, including 83 upregulated circRNAs, and 52 down-regulated circRNAs. RT-qPCR confirmed that 10 circRNAs were all abnormally expressed in OLP. The GO functional analysis and KEGG pathway analysis showed that differentially expressed circRNAs were involved in 535 GO functional items and 78 signal pathways. A ceRNA network analysis showed that circRNAs might interact with a variety of miRNAs. This study mapped the expression profile of abnormally expressed circRNAs in OLP tissues for the first time and showed that circRNAs appear to play an important role in the pathogenesis of OLP.

Expression Profile of Long Noncoding RNAs and Circular RNAs in Mouse C3H10T1/2 Mesenchymal Stem Cells Undergoing Myogenic and Cardiomyogenic Differentiation.

Background Currently, a heterogeneous category of noncoding RNAs (ncRNA) that directly regulate the expression or function of protein-coding genes is shown to have an effect on the fate decision of stem cells. However, the detailed regulatory roles of ncRNAs in myogenic and cardiomyogenic differentiation of mouse C3H10T1/2 mesenchymal stem cells (MSCs) are far from clear. Methods In this study, 5-azacytidine- (5-AZA-) treated C3H10T1/2 cells were differentiated into myocyte-like and cardiomyocyte-like cells. Next, ncRNA associated with myogenic and cardiomyogenic differentiation was identified using high-throughput RNA sequencing (RNA-seq) data. Bioinformatics analysis was conducted to identify the differentially expressed ncRNAs and the related signaling pathways. Results Myotube-like structure was formed after 5-AZA treatment of C3H10T1/2 cells. In addition, myogenic and cardiomyogenic differentiation-related genes like GATA4, cTnt, MyoD, and Desmin were upregulated significantly after the 5-AZA treatment. Totally, 1538 differentially expressed lncRNAs and 3398 differentially expressed mRNAs were identified, including 1175 upregulated and 363 downregulated lncRNAs and 2429 upregulated and 969 downregulated mRNAs. In addition, 46 differentially expressed circRNAs were identified, including 25 upregulated and 21 downregulated circRNAs. Moreover, the differentially expressed mRNAs were enriched into 5 significant pathways, including those for focal adhesion, ECM-receptor interaction, PI3K-AKT signaling pathway, PPAR signaling pathway, and Tyrosine metabolism. Conclusions A systematic view of the expression of ncRNAs in myogenic and cardiomyogenic differentiation of MSCs was provided in the study.

Construction and topological analysis of an endometriosis-related exosomal circRNA-miRNA-mRNA regulatory network.

Novel biomarkers are needed to accelerate the diagnosis and treatment of endometriosis. We performed RNA sequencing to explore the expression profiles of exosomal circular RNAs (circRNAs), microRNAs (miRNAs) and mRNAs in patients with ovarian endometriomas, eutopic endometria and normal endometria. Differentially expressed genes between the different pairs of groups were analyzed and functionally annotated. Then, miRNA-target RNA pairs were identified, competing endogenous RNA (ceRNA) scores were calculated, gene expression characteristics were determined, and these parameters were used to construct an exosomal ceRNA network. We identified 36 candidate hub genes with high degrees of gene connectivity. We also topologically analyzed the ceRNA network to obtain a hub ceRNA network of circRNAs with the highest closeness and ceRNA efficiency. Twelve genes overlapped between the 36 candidate hub genes and the genes in the hub ceRNA network. These 12 genes were considered to be exosomal RNA-based biomarkers, and circ_0026129/miRNA-15a-5p/ATPase H+ transporting V1 subunit A (ATP6V1A) were at the center of the ceRNA network. By determining the exosomal RNA expression profiles of endometriosis patients and constructing a circRNA-associated ceRNA network, these findings provide insight into the molecular pathways of endometriosis and new resources for its diagnosis and treatment.

Circular RNA expression profiles in the plasma of patients with infantile hemangioma determined using microarray analysis

Circular RNAs (circRNAs) are noncoding RNAs that have important roles in tumor progression. Previous studies have examined the circRNAs involved in infantile hemangioma (IH) tumors. The present study compared the circRNA levels in plasma samples from patients with IH and control individuals. The circRNA expression profiles were determined using microarray in three pairs of plasma samples from patients with proliferative IH and healthy control subjects. Expression of the identified differentially expressed circRNAs was verified using reverse transcription-quantitative PCR (RT-qPCR) and a bioinformatics analysis was performed to predict the microRNAs targeted by the validated circRNAs. From the circRNA expression profiles in the plasma of patients with IHs, 128 differentially expressed circRNAs were identified, of which 72 were upregulated and 56 were downregulated. The downregulated expression of three circRNAs [Homo sapiens (hsa)_circRNA_101566, hsa_circRNA_103546 and hsa_circRNA_103573] was verified using RT-qPCR. Gene Ontology term and Kyoto Encyclopedia of Genes and Genomes pathway analyses indicated that all identified networks participated in angiogenesis and tumor formation and progression. It was determined that hsa_circRNA_101566, which is able to regulate the mTOR signaling pathway, may be an important regulatory molecule in IH development and that targeting of hsa_miR_520c is able to indirectly regulate the vascular endothelial growth factor signaling pathway. Further studies are required to clarify these effects and the underlying mechanisms.

Differential circular RNA expression profiles in umbilical cord blood exosomes from preeclampsia patients

BackgroundExosomal circular RNAs (circRNAs) are emerging as important regulators of physiological development and disease pathogenesis. However, the roles of exosomal circRNAs from umbilical cord blood in preeclampsia (PE) occurrence remains poorly understood.MethodsWe used microarray technology to establish the differential circRNA expression profiles in umbilical cord blood exosomes from PE patients compared with normal controls. Bioinformatics analysis was conducted to further predict the potential effects of the differentially expressed circRNAs and their interactions with miRNAs.ResultsAccording to the microarray data, we identified 143 significantly up-regulated circRNAs and 161 significantly down-regulated circRNAs in umbilical cord blood exosomes of PE patients compared with controls. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathway analyses showed that circRNA parental genes involved in the regulation of metabolic process, trophoblast growth and invasion were significantly enriched, which play important roles in PE development. Moreover, pathway network was constructed to reveal the key pathways in PE, such as PI3K-Akt signaling pathway. Further circRNA/miRNA interactions analysis demonstrated that most exosomal circRNAs had miRNA binding sites, and some miRNAs were associated with PE.ConclusionsOur results highlight the importance of exosomal circRNAs in the pathogenesis of PE and lay a foundation for extensive studies on the role of exosomal circRNAs in PE development.

Differential expression profiles of circular RNAs in the rat hippocampus after deep hypothermic circulatory arrest.

Neurological dysfunction commonly occurs after cardiac surgery with deep hypothermic circulatory arrest (DHCA). The mechanisms underlying DHCA-associated brain injury remain poorly understood. This study determined the changes in expressionprofiles of circular RNAs (circRNAs) in the hippocampus in rats that underwent DHCA, with an attempt to explore the potential role of circRNAs in the brain injury associated with DHCA. Adult male Sprague Dawley rats were subjected to cardiopulmonary bypass with DHCA. Brain injury was evaluated by neurological severity scores and histological as well as transmission electron microscope examinations. The expression profiles of circRNAs in the hippocampal tissues were screened by microarray. Quantitative real-time PCR (RT-qPCR) was used to validate the reliability of the microarray results. Bioinformatic algorithms were applied to construct a competing endogenousRNA (ceRNA) network, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to explore the potential biological roles of the circRNAs. Out of 14145 circRNAs screened, 56 were differentially expressed in the hippocampus between the DHCA and sham-operated rats, including 30 upregulated and 26 downregulated circRNAs. The expression changes of six selected circRNAs (upregulated: rno_circRNA_011190, rno_circRNA_012988, rno_circRNA_000544; downregulated: rno_circRNA_010393, rno_circRNA_012043, rno_circRNA_015149) were further confirmed by RT-qPCR. Bioinformatics analysis showed the enrichment of these confirmed circRNAs and their potential target mRNAs in several KEGG pathways including histidine metabolism, adipocytokine signaling, and cAMP signaling. By revealing the change expression profiles of circRNAs in the brain after DHCA, this study indicates possible involvements of these dysregulated circRNAs in brain injury and suggests a potential of targeting circRNAs for prevention and treatment of neurological dysfunction associated with DHCA.

Differential circRNA expression profiles in peripheral blood mononuclear cells among mild and severe influenza-associated pneumonia patients

Objective: To explore the difference in the expression profile of circular RNA in peripheral blood mononuclear cells between patients with mild and severe influenza pneumonia. Methods: From December 2018 to March 2019, 10 inpatients with mild and 10 inpatients with severe influenza pneumonia admitted to the Department of Infection and Clinical Microbiology of Beijing Chaoyang Hospital were included. Clariom™ D gene chip was used to explore the circRNA expression profiles of peripheral blood mononuclear cells (PBMC) isolated from the patients. The absolute value of the fold change (FC value)>2 and P<0.05 were used as the criteria to screen the differentially expressed circRNA, and the gene ontology (GO) enrichment analysis and the Kyoto Encyclopedia of Gene and Genome database (Kyoto Encyclopedia of Genes and Genomes, KEGG) signal pathway enrichment analysis were also performed. Results: The age of mild patients [M (P25, P75)] was 62.0 (34.5, 69.8) years old, including 4 males; the age of severe patients [M (P25, P75)] was 50.0 (37.0, 60.0) years old, all were males. A total of 137 differentially expressed circRNAs in PBMCs of mild and severe patients were screened. The numbers of up-regulated and down-regulated circRNAs in mild patients were 101 and 36, respectively. Among them, hsa_circ_0091073 (FC value=160.898, P<0.05) was the most significantly up-regulated circRNA and hsa_circ_0092219 (FC value =-17.630, P<0.05) was the most significantly down-regulated circRNA. GO enrichment analysis showed that a total of 111 secondary GO items were significantly associated with related differential expression of circRNA (P<0.05). The GO terms associated with upregulated circRNAs included DNA-templated transcription, regulation of DNA-templated transcription, regulation of transcription from RNA polymerase Ⅱ promoter, etc.; The GO terms associated with downregulated circRNAs included neutrophil degranulation, killing of cells of other organism, defense response to fungus, etc. KEGG signaling pathway analysis showed that there were 37 metabolic pathways related to differentially expressed circRNAs (P<0.05). Signaling pathways related to up-regulated circRNAs included nuclear factor-κB (NF-κB) signaling pathway, mitogen-activated protein kinase (MAPK) signaling pathway, tumor necrosis factor (TNF) signaling pathway, etc. Signaling pathways related to down-regulation of circRNAs included cancer transcription disorders, folate carbon pool, and other types of O-glycan biosynthesis. Conclusion: The expression of circRNA in PBMC of mild and severe influenza pneumonia patients is significantly different, and it may play a role in the pathogenic mechanism of influenza pneumonia through multiple signal pathways.

Altered circular RNA expression profiles in an ovalbumin-induced murine model of allergic rhinitis.

Emerging evidence shows that circular RNAs (circRNAs) participate in the pathogenesis of multiple immune diseases. However, few studies have focused on the mechanisms of circRNAs involved in allergic rhinitis (AR). This study performed an RNA sequence (RNA-seq) profiling to identify the expression of circRNAs in nasal mucosa from ovalbumin-induced AR murine models and normal controls. Quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) was then conducted to validate the differential expression of circRNAs. Bioinformatics analysis was applied to demonstrate the biological functions of the dysregulated circRNAs. A total of 86 distinct circRNA candidates were sequenced, of which 51 were upregulated and 35 were downregulated. The T cell receptor, B cell receptor, and calcium signaling pathways may be involved in the pathology of AR. Furthermore, a circRNA-miRNA interaction network was constructed via miRNA response elements analysis. Some circRNAs were correlated with miRNAs that are involved in T cell polarization and activation, thereby highlighting their potential role in the pathogenesis of AR. This study demonstrates a number of aberrantly expressed circRNAs related to AR, and offers a novel perspective into AR pathogenesis and future therapeutic strategies.