Circular RNAs (circRNAs) have emerged as a novel type of non-coding RNA (ncRNA) of interest in gene regulation, especially for its vital function underlying many diseases. Atrial fibrillation is the most common sustained arrythmia. However, the expression spectrum and function of circRNAs in atrial appendage of patients with atrial fibrillation (AF) has seldomly been investigated. Human atrial appendage tissues were acquired during cardiac surgery, which were divided into the AF group and the Sinus rhythm (SR) group. The expression characterization of circRNAs of two groups was revealed by high-throughput sequencing. The dysregulated circRNAs were identified and analyzed by bioinformatics methods, and further validated by realtime PCR. A total 18109 circRNAs in human atrial appendage tissues were targeted. Among them, 147 differentially expressed circRNAs (102 up-regulated and 45 down-regulated) were found between AF group and SR group. Gene ontology (GO) and KEGG pathway analysis indicated that many mRNAs transcribed from the host genes of altered circRNAs were implicated in regulation of sequence-specific DNA binding transcription factor activity, as well as nicotinate and nicotinamide metabolism pathways. Analysis of the association between differently expressed circRNA and miRNA were explored, which revealed an ample interaction. Our study firstly revealed the expression spectrum of circRNAs in both left and right atrial appendage of patients with or without AF. Differentially expressed circRNAs in the atrial appendage were also identified, analyzed and validated. The results of this study may provide novel biomarkers and potential therapeutic targets for AF.

中文翻译：

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房颤患者心耳中环状RNA的鉴定和表征。

环状RNA（circRNA）已作为基因调控中一种新型的非编码RNA（ncRNA）出现，特别是由于其在许多疾病中的重要功能。心房颤动是最常见的持续性心律失常。但是，很少研究circRNA在房颤患者房颤中的表达谱和功能。心脏手术中采集人的心耳组织，分为AF组和窦性心律（SR）组。通过高通量测序揭示了两组circRNA的表达特征。通过生物信息学方法鉴定和分析失调的circRNA，并通过实时PCR进一步验证。靶向人心耳附件组织中的总共18109个circRNA。其中，在AF组和SR组之间发现了147个差异表达的circRNA（102个上调和45个下调）。基因本体论（GO）和KEGG通路分析表明，从改变的circRNA宿主基因转录的许多mRNA与序列特异性DNA结合转录因子活性以及烟酸和烟酰胺代谢途径的调控有关。探索了不同表达的circRNA和miRNA之间的关联分析，揭示了充分的相互作用。我们的研究首先揭示了有或没有房颤的患者左右心耳中circRNA的表达谱。还鉴定，分析和验证了心房附件中差异表达的circRNA。