Zheng Haoyuan, Shi Lin, Tong Changci, Liu Yunen, Hou Mingxiao
Laboratory of Rescue Center of Severe Wound and Trauma Chinese People's Liberation Army, Department of Cardiovascular Surgery, General Hospital of Northern Theater Command of China Medical University, Shenyang, China.
Laboratory of Rescue Center of Severe Wound and Trauma Chinese People's Liberation Army, Emergency Medicine Department of General Hospital of Northern Theater Command, Shenyang, China.
Front Cardiovasc Med. 2021 Apr 21;8:656093. doi: 10.3389/fcvm.2021.656093. eCollection 2021.
Circular RNA (circRNA) is a subclass of non-coding RNAs that enables the circular transcripts resistant to the exonuclease digestion. Iron homeostasis is essential for the body to maintain normal physiological functions. At present, the relationship among circRNA, iron metabolism and heart failure remains largely unknown. This study aimed to explore the regulatory mechanism of circRNA and iron metabolism in heart failure. We obtained circRNA, miRNA and mRNA data from public databases and built a ceRNA network. The prediction results were verified in the myocardial tissues of pressure overload-induced heart failure mice through the use of histopathological staining methods, iron and malondialdehyde (MDA) measurement tests, quantitative real-time PCR (qRT-PCR), Western blot analysis and luciferase reporter assay. A total of 4 genes related to iron metabolism and oxidative stress were identified, and a ceRNA network involving 7 circRNAs, 7 miRNAs, and 4 mRNAs was constructed using bioinformatics tools. The results of qRT-PCR and Western blot analyses indicated that the expression level of FTH1 was similar with that predicted by bioinformatics analysis. Echocardiographic measurement showed that heart failure mice have lower fractional shortening and ejection fraction. Moreover, the myocardium of heart failure mice displayed obvious fibrosis as well as increased levels of iron and MDA compared to control mice. Besides, circSnx12 could act as an endogenous sponge to bind with miR-224-5p, and the 3'UTR region of FTH1 also had miRNA binding sites. A circRNA-miRNA-mRNA regulatory network was successfully constructed by identifying differentially expressed genes related to iron metabolism. This new approach reveals potential circRNA targets for the treatment of heart failure.
环状RNA（circRNA）是一类非编码RNA，其环状转录本能够抵抗核酸外切酶的消化。铁稳态对于机体维持正常生理功能至关重要。目前，circRNA、铁代谢与心力衰竭之间的关系仍 largely未知。本研究旨在探讨circRNA和铁代谢在心力衰竭中的调控机制。我们从公共数据库获取circRNA、miRNA和mRNA数据并构建了ceRNA网络。通过组织病理学染色方法、铁和丙二醛（MDA）测量试验、定量实时PCR（qRT-PCR）、蛋白质印迹分析和荧光素酶报告基因检测，在压力超负荷诱导的心力衰竭小鼠心肌组织中验证了预测结果。共鉴定出4个与铁代谢和氧化应激相关的基因，并使用生物信息学工具构建了一个包含7个circRNA、7个miRNA和4个mRNA的ceRNA网络。qRT-PCR和蛋白质印迹分析结果表明，FTH1的表达水平与生物信息学分析预测的结果相似。超声心动图测量显示，心力衰竭小鼠的缩短分数和射血分数较低。此外，与对照小鼠相比，心力衰竭小鼠的心肌显示出明显的纤维化以及铁和MDA水平升高。此外，circSnx12可以作为内源性海绵与miR-224-5p结合，并且FTH1的3'UTR区域也有miRNA结合位点。通过鉴定与铁代谢相关的差异表达基因，成功构建了一个circRNA-miRNA-mRNA调控网络。这种新方法揭示了治疗心力衰竭的潜在circRNA靶点。
