Project description:Purpose: circRNAs emerge as critical modulators in various biogical processes, but their roles in intestinal stem cells (ISC) reamin unclear. Here we want to identify a functional circRNA in ISCs, and firstly, we explore the expression profile of circRNA in ISCs. Methods: We isolated Lgr5+ ISCs and Lgr5- non-ISCs from the intestine tissue, followed by circRNA seq. Results: Many circRNAs are differently expressed in ISCs and non-ISCs, and we selected circRNAs highly expressed in ISCs for further investigation. Conclusions: circRNAs may play a critical role in ISC self-renewal.
Project description:To explore the role of circRNAs in intestinal stem cells, we isolated small intestinal crypts from C57BL/6 mice and performed high throughput circRNA-seq.
Project description:Circular RNA expression profiling of human nucleus pulposus derived from patients with IDD in comparison with those derived from cadaveric disc as normal control. We have identified the expression profiles of miRNAs (GSE63492), lncRNAs, mRNAs (GSE56081) in IDD using 5 normal discs as control and 5 IDD discs. Accumulating evidence indicates that circRNAs are key regulators of gene expression by interacting with miRNAs. circRNA is a novel type of RNA that, unlike linear RNA, forms a covalently closed continuous loop, and is highly represented in the eukaryotic transcriptome. Two-condition experiment: control nucleus pulposus vs. degenerative nucleus pulposus. Biological replicates: 5 control, 5 degenerated, independently harvested (the same samples as GSE56081 and GSE63492). Four replicates per array.
Project description:To explore the potential involvement of circular RNAs (circRNAs) in pancreatic ductal adenocarcinoma (PDAC) oncogenesis, we conducted circRNA profiling in six pairs of human PDAC and adjacent normal tissue by microarray. Our results showed that clusters of circRNAs were aberrantly expressed in PDAC compared with normal samples, and provided potential targets for future treatment of PDAC and novel insights into PDAC biology. Analyze circular RNA expression in pancreatic ductal adenocarcinoma (PDAC) by microarray platform.
Project description:MicroRNA (miRNA) sponges containing miRNA complementary binding sites constitute a potentially useful strategy for miRNA-inhibition therapeutics in cancer patients. Recently, naturally occurring circular RNAs (circRNAs) have been revealed to function as efficient microRNA sponges. We hypothesized that synthetic circRNA sponges targeting oncomiRs could be constructed and used to achieve potentially therapeutic microRNA loss of function. In this study, linear RNA molecules containing five miR-21 binding sites were transcribed in vitro. After dephosphorylation by calf intestinal phosphatase and phosphorylation by T4 polynucleotide kinase, circRNA sponges were circularized using 5’-3’ end ligation by T4 RNA ligase 1. Synthetic circular sponge stability was assayed in the presence of RNase R or fetal bovine serum. Luciferase reporter and cell proliferation assays were performed to assess competitive inhibition of miR-21 activity by circRNA sponges in NCI-N87 gastric cancer cells. Tandem Mass Tag (TMT) labeling proteomics analysis and Western blotting were performed to delineate effects of circRNA sponges on miR-21 downstream targeted proteins. Our experiments revealed that artificial circRNA sponges can be synthesized using enzymatic ligation. These synthetic circRNA sponges are more resistant than their linear RNA counterparts to nuclease degradation in vitro. They effectively suppress the activity of miR-21 on its downstream protein targets, including the important cancer protein DAXX. Finally, they also inhibit gastric cancer cell proliferation. Our results suggest that synthetic circRNA sponges represent a rapid, effective, convenient strategy to achieve loss of miRNA function in vitro, with potential future therapeutic application in vivo.
Project description:Diabetic retinopathy (DR) is one of the common chronic complications of diabetes. Circular RNA (circRNA) plays a vital role in the pathological process of diabetic retinopathy (DR), this study aims to explore the differences in circRNA expression profiles and functions between DR and non-DR patients.Serum from diabetes mellitus (DM) patients with DR (n=5) and without DR (n=5) were extracted for circRNA microarray analysis using Arraystar Human circRNA expression profile (v2.0). Another 5 DR and 5 non-DR patients were included for quantitative reverse transcription polymerase chain reaction (RT-qPCR) validation. Enriched signaling pathways were analyzed by GO and KEGG analysis. circRNA–miRNA networks were constructed by bioinformatics analysis.
Project description:Circular RNAs (circRNAs), formed by the atypical head-to-tail splicing of exons, have re-emerged as a potentially interesting RNA species given recent reports of a surprising diversity and abundance of circRNA in organisms ranging from worm to human. Here, using deep RNA sequencing, we profiled different RNA species in mouse and observed that circRNAs are significantly enriched in neural tissue, relative to other tissues. Using PacBio sequencing, we determined, for the first time, the circular structure of this population of circRNAs as well as their full-length sequences. We discovered that a disproportionate fraction of the brain circRNA population is derived from host genes that code for synaptic proteins. Moreover, based on the separate profiling of the RNAs localized in neuronal cell bodies and neuropil (enriched in axons and dendrites), we found that, on average, circular RNAs are more enriched in the neuropil than their host gene mRNA isoforms. Using high resolution in situ hybridization we, for the first time, directly visualized circRNA punctae in the dendrites of neurons. The host gene origin and location of the circRNA in neurons suggest the possibility that circRNAs might participate in the regulation of synaptic function and plasticity. Consistent with this idea, we observed via profiling at different developmental stages, that the abundance of many circular RNAs changes abruptly at a time corresponding to synaptogenesis. In addition, following a homeostatic downscaling of neuronal activity many circRNAs exhibit significant up or down-regulation. These data indicate that brain circRNAs are positioned to respond to and regulate synaptic function. Circular RNA profiling in 13 different samples in mice and four samples in rat, using Illumina sequencing
Project description:Circular RNAs (circRNAs) represent a widespread class of non-coding RNAs, which drew little attention in the past. Recently, limited data showed their promising future to act as biomarkers in human cancer, but the characteristics and functions remain largely unknown in hematopoietic malignancies, especially in leukemia. In this study, with the help of circRNA microarray, we demonstrated the expression profile of circRNAs in acute myeloid leukemia (AML) patients, and identified a large number of circRNAs possibly expressed in a leukemia specific manner. We also described a circRNA signature related to AML risk-status based on the bioinformatics prediction.