Department of Pathology and Medical Biology, University Medical Center Groningen, The University of Groningen, Groningen, The Netherlands.
Department of Pulmonary Diseases, University Medical Center Groningen, The University of Groningen, Groningen, The Netherlands.
Sci Rep. 2022 Apr 4;12(1):5610. doi: 10.1038/s41598-022-09093-0.
Smoking is a leading cause of chronic obstructive pulmonary disease (COPD). It is known to have a significant impact on gene expression and (inflammatory) cell populations in the airways involved in COPD pathogenesis. In this study, we investigated the impact of smoking on the expression of miRNAs in healthy and COPD individuals. We aimed to elucidate the overall smoking-induced miRNA changes and those specific to COPD. In addition, we investigated the downstream effects on regulatory gene expression and the correlation to cellular composition. We performed a genome-wide miRNA expression analysis on a dataset of 40 current- and 22 ex-smoking COPD patients and a dataset of 35 current- and 38 non-smoking respiratory healthy controls and validated the results in an independent dataset. miRNA expression was then correlated with mRNA expression in the same patients to assess potential regulatory effects of the miRNAs. Finally, cellular deconvolution analysis was used to relate miRNAs changes to specific cell populations. Current smoking was associated with increased expression of three miRNAs in the COPD patients and 18 miRNAs in the asymptomatic smokers compared to respiratory healthy controls. In comparison, four miRNAs were lower expressed with current smoking in asymptomatic controls. Two of the three smoking-related miRNAs in COPD, miR-203a-3p and miR-375, were also higher expressed with current smoking in COPD patients and the asymptomatic controls. The other smoking-related miRNA in COPD patients, i.e. miR-31-3p, was not present in the respiratory healthy control dataset. miRNA-mRNA correlations demonstrated that miR-203a-3p, miR-375 and also miR-31-3p expression were negatively associated with genes involved in pro-inflammatory pathways and positively associated with genes involved in the xenobiotic pathway. Cellular deconvolution showed that higher levels of miR-203a-3p were associated with higher proportions of proliferating-basal cells and secretory (club and goblet) cells and lower levels of fibroblasts, luminal macrophages, endothelial cells, B-cells, amongst other cell types. MiR-375 expression was associated with lower levels of secretory cells, ionocytes and submucosal cells, but higher levels of endothelial cells, smooth muscle cells, and mast cells, amongst other cell types. In conclusion, we identified two smoking-induced miRNAs (miR-375 and miR-203a-3p) that play a role in regulating inflammation and detoxification pathways, regardless of the presence or absence of COPD. Additionally, in patients with COPD, we identified miR-31-3p as a miRNA induced by smoking. Our identified miRNAs should be studied further to unravel which smoking-induced inflammatory mechanisms are reactive and which are involved in COPD pathogenesis.
吸烟是慢性阻塞性肺疾病（COPD）的主要病因。已知它对 COPD 发病机制中涉及的气道中的基因表达和（炎症）细胞群有重大影响。在这项研究中，我们调查了吸烟对健康人和 COPD 个体中 miRNA 表达的影响。我们旨在阐明整体吸烟诱导的 miRNA 变化以及 COPD 特有的变化。此外，我们还研究了对调节基因表达的下游影响以及与细胞组成的相关性。我们对 40 名当前吸烟和 22 名曾吸烟的 COPD 患者以及 35 名当前吸烟和 38 名非吸烟呼吸道健康对照者的数据集进行了全基因组 miRNA 表达分析，并在独立数据集进行了验证。然后，将 miRNA 表达与同一患者的 mRNA 表达相关联，以评估 miRNA 的潜在调节作用。最后，使用细胞去卷积分析将 miRNA 变化与特定细胞群相关联。与呼吸道健康对照组相比，当前吸烟与 COPD 患者中三种 miRNA 的表达增加有关，与无症状吸烟者中 18 种 miRNA 的表达增加有关。相比之下，在无症状对照组中，有四种 miRNA 的表达随着当前吸烟而降低。在 COPD 患者中，与吸烟相关的三种 miRNA 中有两种，即 miR-203a-3p 和 miR-375，也与 COPD 患者和无症状对照组的当前吸烟有关。COPD 患者中另一种与吸烟相关的 miRNA，即 miR-31-3p，不存在于呼吸道健康对照组数据集中。miRNA-mRNA 相关性表明，miR-203a-3p、miR-375 和 miR-31-3p 的表达与参与促炎途径的基因呈负相关，与参与外来物途径的基因呈正相关。细胞去卷积表明，miR-203a-3p 水平升高与增殖基底细胞和分泌（棒状和杯状）细胞的比例升高有关，与成纤维细胞、管腔巨噬细胞、内皮细胞、B 细胞等其他细胞类型的比例降低有关。miR-375 的表达与分泌细胞、离子细胞和黏膜下细胞的水平降低有关，但与内皮细胞、平滑肌细胞和肥大细胞等其他细胞类型的水平升高有关。总之，我们确定了两种由吸烟诱导的 miRNA（miR-375 和 miR-203a-3p），它们在调节炎症和解毒途径中发挥作用，无论 COPD 是否存在。此外，在 COPD 患者中，我们确定了 miR-31-3p 是一种由吸烟诱导的 miRNA。我们确定的 miRNA 应进一步研究，以揭示哪些由吸烟诱导的炎症机制是反应性的，哪些与 COPD 发病机制有关。
