China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Center of Respiratory Medicine, China-Japan Friendship Hospital, National Center for Respiratory Medicine, Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, National Clinical Research Center for Respiratory Diseases, State Key Laboratory of Respiratory Health and Multi Morbidity, No 2, East Yinghua Road, Chaoyang District, Beijing, 100029, China.
Respir Res. 2024 Feb 20;25(1):93. doi: 10.1186/s12931-024-02736-y.
Chronic obstructive pulmonary disease (COPD) is a common respiratory disease and represents the third leading cause of death worldwide. This study aimed to investigate miRNA regulation of Receptor for Advanced Glycation End-products (RAGE), a causal receptor in the pathogenesis of cigarette smoke (CS)-related COPD, to guide development of therapeutic strategies.
RAGE expression was quantified in lung tissue of COPD patients and healthy controls, and in mice with CS-induced COPD. RNA-sequencing of peripheral blood from COPD patients with binding site prediction was used to screen differentially expressed miRNAs that may interact with RAGE. Investigation of miR-23a-5p as a potential regulator of COPD progression was conducted with miR-23a-5p agomir in COPD mice in vivo using histology and SCIREQ functional assays, while miR-23a-5p mimics or RAGE inhibitor were applied in 16-HBE human bronchial epithelial cells in vitro. RNA-sequencing, ELISA, and standard molecular techniques were used to characterize downstream signaling pathways in COPD mice and 16-HBE cells treated with cigarette smoke extract (CSE).
RAGE expression is significantly increased in lung tissue of COPD patients, COPD model mice, and CSE-treated 16-HBE cells, while inhibiting RAGE expression significantly reduces COPD severity in mice. RNA-seq analysis of peripheral blood from COPD patients identified miR-23a-5p as the most significant candidate miRNA interaction partner of RAGE, and miR-23a-5p is significantly downregulated in mice and cells treated with CS or CSE, respectively. Injection of miR-23a-5p agomir leads to significantly reduced airway inflammation and alleviation of symptoms in COPD mice, while overexpressing miR-23a-5p leads to improved lung function. RNA-seq with validation confirmed that reactive oxygen species (ROS) signaling is increased under CSE-induced aberrant upregulation of RAGE, and suppressed in CSE-stimulated cells treated with miR-23a-5p mimics or overexpression. ERK phosphorylation and subsequent cytokine production was also increased under RAGE activation, but inhibited by increasing miR-23a-5p levels, implying that the miR-23a-5p/RAGE/ROS axis mediates COPD pathogenesis via ERK activation.
This study identifies a miR-23a-5p/RAGE/ROS signaling axis required for pathogenesis of COPD. MiR-23a-5p functions as a negative regulator of RAGE and downstream activation of ROS signaling, and can inhibit COPD progression in vitro and in vivo, suggesting therapeutic targets to improve COPD treatment.
慢性阻塞性肺疾病（COPD）是一种常见的呼吸系统疾病，也是全球范围内的第三大死亡原因。本研究旨在探究微小 RNA（miRNA）对晚期糖基化终产物受体（RAGE）的调控作用，RAGE 是香烟烟雾（CS）相关 COPD 发病机制中的一个因果受体，这将为治疗策略的制定提供指导。
通过定量分析 COPD 患者和健康对照者的肺组织以及 CS 诱导的 COPD 小鼠中的 RAGE 表达，采用 COPD 患者外周血的 RNA 测序和结合部位预测筛选可能与 RAGE 相互作用的差异表达 miRNA。通过 miR-23a-5p 激动剂在 COPD 小鼠体内进行组织学和 SCIREQ 功能测定，探究 miR-23a-5p 作为 COPD 进展潜在调控因子的作用，同时在体外应用 miR-23a-5p 模拟物或 RAGE 抑制剂处理 16-HBE 人支气管上皮细胞。采用 RNA 测序、ELISA 和标准分子技术，分析 COPD 小鼠和用香烟烟雾提取物（CSE）处理的 16-HBE 细胞中的下游信号通路。
COPD 患者、COPD 模型小鼠和 CSE 处理的 16-HBE 细胞中的 RAGE 表达显著增加，而抑制 RAGE 表达可显著减轻小鼠 COPD 的严重程度。COPD 患者外周血的 RNA 测序分析确定 miR-23a-5p 为 RAGE 最显著的候选 miRNA 相互作用伙伴，并且 miR-23a-5p 在 CS 处理的小鼠和细胞中分别显著下调。miR-23a-5p 激动剂的注射导致 COPD 小鼠的气道炎症显著减少，症状得到缓解，而过表达 miR-23a-5p 可改善肺功能。miR-23a-5p 模拟物或过表达可抑制 CSE 刺激的细胞中 RAGE 异常上调诱导的活性氧（ROS）信号的增加，经验证的 RNA 测序证实了这一点。ERK 磷酸化和随后的细胞因子产生也在 RAGE 激活下增加，但通过增加 miR-23a-5p 水平抑制，表明 miR-23a-5p/RAGE/ROS 轴通过 ERK 激活介导 COPD 的发病机制。
本研究确定了 miR-23a-5p/RAGE/ROS 信号通路是 COPD 发病机制所必需的。miR-23a-5p 作为 RAGE 的负调节剂和下游 ROS 信号的激活物发挥作用，可在体内外抑制 COPD 的进展，提示改善 COPD 治疗的治疗靶点。
