CircRNA_0263 and circRNA_1507 are Dysregulated in Atrial Fibrosis Rat Induced by Chronic Intermittent Hypoxia
Abstract Aims: This study aimed to characterize circular RNA (circRNA) profiles associated with atrial fibrosis and identify critical circRNAs in a rat model of atrial fibrosis.Methods: Sprague Dawley rats were randomly divided into control and atrial fibrosis groups (n=15 in each group). For rats in the atrial fibrosis group, atrial fibrosis was induced by chronic intermittent hypoxia. Atrial tissues were isolated for circRNA sequencing. The dysregulated circRNAs in atrial fibrosis were identified by DESeq. Subsequently, the potential functions of circRNAs in atrial fibrosis were investigated by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis of the host genes. The interactions among circRNAs, microRNAs (miRNAs), and mRNAs were analyzed by constructing a competing endogenous RNA (ceRNA) network. Finally, the crucial circRNAs were validated by quantitative real-time polymerase chain reaction (qRT-PCR).Results: Five upregulated and 11 downregulated circRNAs were identified in the atrial fibrosis group. These dysregulated circRNAs were primarily associated with “carbohydrate metabolism” and “cardiovascular diseases.” Two circRNAs (circRNA_0263 and circRNA_1507) were able to regulate target gene expression by interacting with corresponding miRNAs, including rno-miR-29b-5p, rno-miR-29b-3p, rno-miR-496-5p, rno-miR-136-5p, and novel123-mature. qRT-PCR successfully validated the differential expression of circRNA_0263 and circRNA_1507.Conclusion: A series of circRNAs were identified as dysregulated in an atrial fibrosis rat model. The dysregulation of two circRNAs (circRNA_0263 and circRNA_1507) might be crucial for atrial fibrosis development by competing with several miRNAs.