Liu Xiaoying, Ali Md Khadem, Dua Kamal, Mao Yuqiang, Liu Jun
Department of Breast Surgery, The First Affiliated Hospital of China Medical University, Shenyang, China.
Pre-Professional Health Academic Program, California State University, Hayward, CA, United States.
Front Cell Dev Biol. 2023 Nov 24;11:1267792. doi: 10.3389/fcell.2023.1267792. eCollection 2023.
Circular RNAs (circRNAs) belong to a unique class of endogenously expressed non-protein-coding RNAs with a distinct circularized structure, characterized by the absence of 5'-cap and 3'-polyadenylate ends. They are generally formed through back-splicing from pre-mRNAs. They serve as regulators of transcription and splicing, and act as sponges for microRNAs (miRNAs) and RNA-binding proteins, thereby modulating the expression of target genes. As a result, they exert a substantial impact on a diverse array of cellular and biological processes, including cell proliferation, migration, inflammation, and oxidative stress. Asthma and COPD are chronic airway conditions that currently have no cure. In recent years, emerging evidence suggests that altered expression of circRNAs in airway, bronchial and immune cells is involved in asthma and COPD pathogenesis. Studies exploring circRNA dysregulation in asthma have showcased their involvement in regulating the proliferation, migration, and inflammation of airway smooth muscle and bronchial epithelial cells, as well as impacting goblet cell metaplasia, Th2 cell differentiation, and macrophage activation, primarily through interactions with miRNAs. Similarly, in COPD, circRNAs have shown altered expression patterns in the blood and lungs of patients, and these changes have been linked to modulating inflammation, oxidative stress, and airway remodeling in preclinical models. Furthermore, certain circRNAs have demonstrated promising potential as diagnostic and prognostic biomarkers for both asthma and COPD. This review delves into the current understanding of the function and molecular mechanisms of circRNAs in asthma and COPD, along with exploring their potential as biomarkers in these respiratory conditions.
环状RNA（circRNAs）属于一类独特的内源性表达的非蛋白质编码RNA，具有独特的环状结构，其特征是没有5'-帽和3'-聚腺苷酸末端。它们通常通过前体mRNA的反向剪接形成。它们作为转录和剪接的调节因子，并充当微小RNA（miRNA）和RNA结合蛋白的海绵，从而调节靶基因的表达。因此，它们对包括细胞增殖、迁移、炎症和氧化应激在内的多种细胞和生物学过程产生重大影响。哮喘和慢性阻塞性肺疾病（COPD）是目前无法治愈的慢性气道疾病。近年来，新出现的证据表明，气道、支气管和免疫细胞中circRNAs表达的改变与哮喘和COPD的发病机制有关。探索哮喘中circRNA失调的研究表明，它们主要通过与miRNA相互作用，参与调节气道平滑肌和支气管上皮细胞的增殖、迁移和炎症，以及影响杯状细胞化生、辅助性T细胞2（Th2）分化和巨噬细胞活化。同样，在COPD中，circRNAs在患者的血液和肺部显示出改变的表达模式，并且这些变化与临床前模型中调节炎症、氧化应激和气道重塑有关。此外，某些circRNAs已显示出作为哮喘和COPD诊断和预后生物标志物的潜在前景。这篇综述深入探讨了目前对circRNAs在哮喘和COPD中的功能和分子机制的理解，同时探索了它们在这些呼吸系统疾病中作为生物标志物的潜力。
