Dept of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
GRIAC Research Institute, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Eur Respir J. 2017 May 25;49(5). doi: 10.1183/13993003.02538-2016. Print 2017 May.
We previously reported that epithelial-derived interleukin (IL)-1α drives fibroblast-derived inflammation in the lung epithelial-mesenchymal trophic unit. Since miR-146a-5p has been shown to negatively regulate IL-1 signalling, we investigated the role of miR-146a-5p in the regulation of IL-1α-driven inflammation in chronic obstructive pulmonary disease (COPD).Human bronchial epithelial (16HBE14o-) cells were co-cultured with control and COPD-derived primary human lung fibroblasts (PHLFs), and miR-146a-5p expression was assessed with and without IL-1α neutralising antibody. Genomic DNA was assessed for the presence of the single nucleotide polymorphism (SNP) rs2910164. miR-146a-5p mimics were used for overexpression studies to assess IL-1α-induced signalling and IL-8 production by PHLFs.Co-culture of PHLFs with airway epithelial cells significantly increased the expression of miR-146a-5p and this induction was dependent on epithelial-derived IL-1α. miR-146a-5p overexpression decreased IL-1α-induced IL-8 secretion in PHLFs downregulation of IL-1 receptor-associated kinase-1. In COPD PHLFs, the induction of miR-146a-5p was significantly less compared with controls and was associated with the SNP rs2910164 (GG allele) in the miR-146a-5p gene.Our results suggest that induction of miR-146a-5p is involved in epithelial-fibroblast communication in the lungs and negatively regulates epithelial-derived IL-1α induction of IL-8 by fibroblasts. The decreased levels of miR-146a-5p in COPD fibroblasts may induce a more pro-inflammatory phenotype, contributing to chronic inflammation in COPD.
我们之前报道过，上皮细胞衍生的白细胞介素（IL）-1α驱动肺上皮-间充质营养单位中的成纤维细胞衍生的炎症。由于 miR-146a-5p 已被证明可负向调节 IL-1 信号，因此我们研究了 miR-146a-5p 在调节慢性阻塞性肺疾病（COPD）中 IL-1α 驱动的炎症中的作用。
将人支气管上皮（16HBE14o-）细胞与对照和 COPD 来源的原代人肺成纤维细胞（PHLFs）共培养，并在存在和不存在 IL-1α 中和抗体的情况下评估 miR-146a-5p 的表达。评估存在单核苷酸多态性（SNP）rs2910164 的基因组 DNA。使用 miR-146a-5p 模拟物进行过表达研究，以评估 PHLFs 中 IL-1α 诱导的信号传导和 IL-8 产生。
PHLFs 与气道上皮细胞共培养可显著增加 miR-146a-5p 的表达，这种诱导依赖于上皮细胞衍生的 IL-1α。miR-146a-5p 过表达可降低 PHLFs 中 IL-1α 诱导的 IL-8 分泌，下调 IL-1 受体相关激酶-1。与对照组相比，COPD PHLFs 中 miR-146a-5p 的诱导显著降低，并且与 miR-146a-5p 基因中的 SNP rs2910164（GG 等位基因）相关。
我们的结果表明，miR-146a-5p 的诱导参与了肺部上皮细胞和成纤维细胞之间的通讯，并负向调节成纤维细胞中上皮细胞衍生的 IL-1α 诱导的 IL-8。COPD 成纤维细胞中 miR-146a-5p 水平降低可能会诱导更具促炎表型，导致 COPD 中的慢性炎症。
