Differentially expressed circular RNAs and the competing endogenous RNA network associated with preeclampsia.
Circular RNAs (circRNAs) are non-coding RNAs that are implicated in preeclampsia (PE) pathogenesis; however, their expression and functions in PE remain unclear. In this study, we aimed to investigate the expression of circRNAs in PE and construct a competing endogenous RNA (ceRNA) network, and analyze the associated pathways in PE pathogenesis.
We performed circRNA sequencing to identify the differential expression profile of circRNAs in PE as compared to normal pregnancy. The circRNA candidates were validated using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Subsequently, we used datasets from the GEO database to generate the interaction network between circRNAs, microRNAs (miRNAs), and mRNAs. GO and KEGG enrichment analyses were performed to understand the functional significance of the differentially expressed circRNAs in PE.
We identified 361 differentially expressed circRNAs (252 upregulated and 109 downregulated) in preeclamptic placentas. Within the selected 31 circRNAs, 6 of them were verified by qRT-PCR. GO and KEGG analyses revealed the potential pathways affected by these circRNAs, e.g., T cell receptor signaling and MAP kinase pathways. A total of 134 miRNAs and 199 mRNAs were revealed to be differentially expressed in PE by analyzing datasets from the GEO database. The circRNA-miRNA-mRNA network comprised 206 circRNAs, 50 miRNAs, and 38 mRNAs. KEGG analysis of the 38 mRNAs included pathways involved in AMPK and PI3K-Akt signaling.
Our results reported the differential expression profile of circRNAs and the circRNA-miRNA-mRNA network in PE, which provides potential therapeutic targets for this disease.
Ma B
,Zhao H
,Gong L
,Xiao X
,Zhou Q
,Lu H
,Cui Y
,Xu H
,Wu S
,Tang Y
,Ye Y
,Gu W
,Li X
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Identification of Serum Exosome-Derived circRNA-miRNA-TF-mRNA Regulatory Network in Postmenopausal Osteoporosis Using Bioinformatics Analysis and Validation in Peripheral Blood-Derived Mononuclear Cells.
Osteoporosis is one of the most common systemic metabolic bone diseases, especially in postmenopausal women. Circular RNA (circRNA) has been implicated in various human diseases. However, the potential role of circRNAs in postmenopausal osteoporosis (PMOP) remains largely unknown. The study aims to identify potential biomarkers and further understand the mechanism of PMOP by constructing a circRNA-associated ceRNA network.
The PMOP-related datasets GSE161361, GSE64433, and GSE56116 were downloaded from the Gene Expression Omnibus (GEO) database and were used to obtain differentially expressed genes (DEGs). Gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were applied to determine possible relevant functions of differentially expressed messenger RNAs (mRNAs). The TRRUST database was used to predict differential transcription factor (TF)-mRNA regulatory pairs. Afterwards, combined CircBank and miRTarBase, circRNA-miRNA as well as miRNA-TF pairs were constructed. Then, a circRNA-miRNA-TF-mRNA network was established. Next, the correlation of mRNAs, TFs, and PMOP was verified by the Comparative Toxicogenomics Database. And expression levels of key genes, including circRNAs, miRNAs, TFs, and mRNAs in the ceRNA network were further validated by quantitative real-time PCR (qRT-PCR). Furthermore, to screen out signaling pathways related to key mRNAs of the ceRNA network, Gene Set Enrichment Analysis (GSEA) was performed.
A total of 1201 DE mRNAs, 44 DE miRNAs, and 1613 DE circRNAs associated with PMOP were obtained. GO function annotation showed DE mRNAs were mainly related to inflammatory responses. KEGG analysis revealed DE mRNAs were mainly enriched in osteoclast differentiation, rheumatoid arthritis, hematopoietic cell lineage, and cytokine-cytokine receptor interaction pathways. We first identified 26 TFs and their target mRNAs. Combining DE miRNAs, miRNA-TF/mRNA pairs were obtained. Combining DE circRNAs, we constructed the ceRNA network contained 6 circRNAs, 4 miRNAs, 4 TFs, and 12 mRNAs. The expression levels of most genes detected by qRT-PCR were generally consistent with the microarray results. Combined with the qRT-PCR validation results, we eventually identified the ceRNA network that contained 4 circRNAs, 3 miRNAs, 3 TFs, and 9 mRNAs. The GSEA revealed that 9 mRNAs participate in many important signaling pathways, such as "olfactory transduction", "T cell receptor signaling pathway", and "neuroactive ligand-receptor interaction". These pathways have been reported to the occurrence and development of PMOP. To sum up, key mRNAs in the ceRNA network may participate in the development of osteoporosis by regulating related signal pathways.
A circRNA-associated ceRNA network containing TFs was established for PMOP. The study may help further explore the molecular mechanisms and may serve as potential biomarkers or therapeutic targets for PMOP.
Dong Q
,Han Z
,Tian L
《Frontiers in Endocrinology》
The expression profile of circRNA and its potential regulatory targets in the placentas of severe pre-eclampsia.
To determine the expression profiles of circular RNAs (circRNAs) of women with severe pre-eclampsia (sPE group) versus normal pregnancies (normal control group).
RNA-sequencing (RNA-seq) was conducted to characterize differentially expressed circRNAs and mRNAs in the placental tissues of women with sPE versus normal pregnancies. circRNA functions were predicted by Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) database analysis. The backsplicing junctions of circRNAs were validated with the use of divergent primers. Relative expression levels of cirRNAs were verified by quantitative real-time PCR (qPCR). A circRNA-miRNA-mRNA interaction network was constructed to outline the regulatory network of the differentially expressed circRNAs.
A total of 49 differentially expressed circRNAs were found in the placental tissues of women with sPE. Several differentially expressed mRNAs were also observed in the sPE patients. KEGG analysis revealed that the most enriched pathway of the circRNAs was the MAPK signaling pathway, while the differentially expressed mRNAs were primary enriched in pathways in cancer. Among these circRNAs, hsa_circ_0001438, hsa_circ_0001326, and hsa_circ_32340 were upregulated in the sPE patients and the circRNA-miRNA-mRNA interaction network generated with these three circRNAs revealed a broad regulatory network that might be involved in the pathogenesis of sPE.
circRNAs are differentially expressed in sPE. The upregulation of hsa_circ_0001438, hsa_circ_0001326, and hsa_circ_32340 has a potential role in the regulation of miRNA and mRNA expression. Changes to the expression profiles of the circRNAs might be linked to the pathogenesis of sPE and could function as biomarkers.
Ou Y
,Liu M
,Zhu L
,Deng K
,Chen M
,Chen H
,Zhang J
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Construction and functional enrichment analysis of the competitive endogenous RNA regulatory network for nonarteritic anterior ischemic optic neuropathy based on high-throughput sequencing.
Based on the transcriptome high-throughput sequencing of nonarteritic anterior ischemic optic neuropathy (NAION), this study constructed a competitive endogenous RNA (ceRNA) network, enriched and analyzed it, screened long noncoding (lnc)RNAs and circular (circ)RNAs that may participate in the competitive endogenous mechanism in NAION, and inferred its function. Four milliliters of peripheral blood from NAION patients and the control group was extracted from clinical samples, transcriptome high-throughput sequencing was performed, and the sequencing data were visualized. Based on the principle of the ceRNA network, the lncRNA-micro (mi)RNA-messenger (m)RNA interaction axis and circRNA-miRNA‒mRNA interaction axes were constructed. The differentially expressed genes (DEGs) in the interaction axis were enriched and analyzed by Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG), and the functions and signalling pathways of lncRNAs and circRNAs in the interaction network were speculated. Fifty-one circRNAs were differentially expressed in the sequencing data: 25 were upregulated, and 26 were downregulated. For 996 differentially expressed lncRNAs, 317 were upregulated and 679 were downregulated, and for 1161 differentially expressed mRNAs, 698 were upregulated and 463 were downregulated. Thirty-three differentially expressed miRNAs, upregulated miRNA 18 and downregulated miRNA 15 were identified. After screening, 13 coexpressed mRNAs, 15 lncRNAs, and 3 miRNAs were finally constructed in the lncRNA-miRNA-mRNA network, and the circRNA-miRNA-mRNA network was constructed by 159 mRNAs, 26 miRNAs, and 34 circRNAs. In the lncRNA network, GO enrichment analysis obtained 182 biological processes, 12 cell components and 38 molecular functions, which are related mainly to the regulation of the activity of proteins and enzymes such as cyclic nucleotide-dependent protein kinase activity and magnesium ion-dependent protein serine/threonine phosphatase activity. KEGG analysis involved mainly the forkhead box O (FoxO) signalling pathway, apelin signalling pathway, etc. In the circRNA enrichment results, 353 biological processes, 52 cell components, and 45 molecular functions were obtained, involving mainly calcium channel regulation, neutrophil activation, mRNA transport, and metabolism. KEGG mainly involved the Wnt signalling pathway, apelin signalling pathway, Hippo signalling pathway, oxytocin signalling pathway, etc. This paper provides a new idea for lncRNAs and circRNAs to mediate the occurrence and development of NAION through the ceRNA mechanism. This study lays a foundation for the in-depth study of the pathogenesis of NAION.
Zhang M
,Wang X
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