Roffel Mirjam P, Brandsma Corry-Anke, Faiz Alen, Jonker Marnix R, Timens Wim, Joos Guy F, Brusselle Guy G, Maes Tania, Bracke Ken R, van den Berge Maarten, Heijink Irene H
University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, The Netherlands; Ghent University, Ghent University Hospital, Laboratory for Translational Research in Obstructive Pulmonary Diseases, Department of Respiratory Medicine, Ghent, Belgium.
University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, The Netherlands.
Arch Bronconeumol. 2025 Jul 5. doi: 10.1016/j.arbres.2025.06.015.
The mechanisms driving abnormal pro-inflammatory responses to cigarette smoke in COPD remain unclear. MicroRNA (miR)-320d was previously shown to have anti-inflammatory effects, being upregulated by inhaled corticosteroids. Therefore, our objective was to study whether miR-320d suppresses smoke-induced airway epithelial pro-inflammatory responses and if this is compromised in COPD.
We investigated the anti-inflammatory mechanisms of miR-320d in cigarette smoke extract (CSE)-exposed primary bronchial epithelial cells (PBECs), comparing COPD and control cells using a miR-320d mimic. Additionally, we assessed whether miR-320d expression is altered with COPD and its severity, investigating lung tissue from two independent cohorts of non-COPD controls (non/current/ex-smokers) and COPD patients (current/ex-smokers) with mild/moderate and severe disease.
MiR-320d overexpression attenuated baseline and CSE-induced pro-inflammatory CXCL8, IL-1α and GM-CSF secretion in non-COPD-derived PBECs. This effect was not observed for CXCL8 and IL-1α in COPD-derived PBECs. RNA-sequencing showed that miR-320d significantly regulates the expression of 137 genes in CSE-exposed epithelium, the upregulated genes being enriched in "interleukin-33-mediated signaling" and the downregulated genes in "response to cytokine" (including IRAK1) pathways. Higher miR-320d levels were associated with lower IRAK1 expression in control but not COPD-derived PBECs. Finally, miR-320d levels were lower in lung tissue of COPD patients vs non-smoking controls and in severe vs mild/moderate COPD patients.
miR-320d's suppressive effect on bronchial epithelial pro-inflammatory responses cells may be compromised in COPD. Additionally, miR-320d expression in lung tissue was lower with COPD severity. Thus, lower miR-320d anti-inflammatory action may contribute to persisting inflammation in COPD.
慢性阻塞性肺疾病（COPD）中驱动对香烟烟雾异常促炎反应的机制仍不清楚。微小RNA（miR）-320d先前已被证明具有抗炎作用，可被吸入性糖皮质激素上调。因此，我们的目标是研究miR-320d是否抑制烟雾诱导的气道上皮促炎反应，以及在COPD中这一作用是否受损。
我们使用miR-320d模拟物，在暴露于香烟烟雾提取物（CSE）的原代支气管上皮细胞（PBECs）中研究miR-320d的抗炎机制，比较COPD患者和对照者的细胞。此外，我们评估了miR-320d表达是否随COPD及其严重程度而改变，研究了来自两个独立队列的非COPD对照者（非吸烟者/当前吸烟者/既往吸烟者）以及患有轻度/中度和重度疾病的COPD患者（当前吸烟者/既往吸烟者）的肺组织。
miR-320d过表达减弱了非COPD来源的PBECs中的基线和CSE诱导的促炎细胞因子CXCL8、IL-1α和GM-CSF的分泌。在COPD来源的PBECs中，未观察到miR-320d对CXCL8和IL-1α的这种作用。RNA测序表明，miR-320d显著调节CSE暴露上皮细胞中137个基因的表达，上调的基因富集于“白细胞介素-33介导的信号传导”，下调的基因富集于“对细胞因子的反应”（包括IRAK1）途径。在对照而非COPD来源的PBECs中，较高的miR-320d水平与较低的IRAK1表达相关。最后，COPD患者肺组织中的miR-320d水平低于非吸烟对照者，且重度COPD患者低于轻度/中度COPD患者。
在COPD中，miR-320d对支气管上皮促炎反应细胞的抑制作用可能受损。此外，肺组织中miR-320d的表达随COPD严重程度降低。因此，较低的miR-320d抗炎作用可能导致COPD中炎症持续存在。
