Department of Otorhinolaryngology-Head and Neck Surgery, Research Institute for Medical Science, Chungnam National University School of Medicine, Daejeon, Korea.
Department of Ophthalmology, Chungnam National University School of Medicine, Daejeon, Korea.
Int Forum Allergy Rhinol. 2018 Sep;8(9):1001-1012. doi: 10.1002/alr.22155. Epub 2018 Jun 14.
Nasal polyposis is characterized by persistent inflammation and remodeling in sinonasal mucosa. Toll-like receptor 9 (TLR9) is a DNA receptor of the innate immune system that plays a pivotal role in fibrosis and inflammatory responses. The aim of this study is to explore the expression, activity, and potential pathogenic role of TLR9 signaling in tissue remodeling in nasal polyp-derived fibroblasts (NPDFs).
Fibrotic and inflammatory responses elicited by type A CpG oligonucleotides were examined in the NPDFs by a combination of real-time quantitative polymerase chain reaction, Western blot analysis, enzyme-linked immunosorbent assay, and immunofluorescence staining. For these experiments, the NPDFs were stimulated with different TLR9 agonists (CpG A and B) and blocked with inhibitors (MyD88 inhibitor and chloroquine).
TLR9 expression was significantly higher in nasal polyposis (NP) tissues compared to control or chronic rhinosinusitis (CRS) mucosa. In the NPDFs, TLR9 showed intracellular localization and expression of TLR9 was increased after treatment with CpG A. CpG A increased production of α-smooth muscle actin (α-SMA), fibronectin, and matrix metalloproteinases (MMPs) (MMP1, MMP2, and MMP9) in the NPDFs, while MyD88 inhibitor and chloroquine, which are known to block the TLR9 signaling pathway, inhibited their production. CpG A also produced type I interferons (IFN-α and IFN-β), which were inhibited by MyD88 inhibitor.
Our data indicates that CpG A-induced fibroblast activation and cytokine production were mediated via TLR9 stimulation in NPDFs. Disrupting this process with an inhibitor targeting TLR9 or its downstream signaling pathways could represent a novel approach to CRS with NP (CRSwNP) therapy.
鼻息肉的特征是鼻黏膜持续的炎症和重塑。Toll 样受体 9（TLR9）是先天免疫系统的 DNA 受体，在纤维化和炎症反应中发挥关键作用。本研究旨在探讨 TLR9 信号在鼻息肉衍生成纤维细胞（NPDFs）组织重塑中的表达、活性及其潜在的致病作用。
通过实时定量聚合酶链反应、Western blot 分析、酶联免疫吸附试验和免疫荧光染色，结合研究 NPDFs 中 A 型 CpG 寡核苷酸引起的纤维化和炎症反应。对于这些实验，用不同的 TLR9 激动剂（CpG A 和 B）刺激 NPDFs，并使用抑制剂（MyD88 抑制剂和氯喹）进行阻断。
与对照或慢性鼻-鼻窦炎（CRS）黏膜相比，TLR9 在鼻息肉（NP）组织中的表达显著升高。在 NPDFs 中，TLR9 表现出细胞内定位，并且在用 CpG A 处理后 TLR9 的表达增加。CpG A 增加了 NPDFs 中 α-平滑肌肌动蛋白（α-SMA）、纤维连接蛋白和基质金属蛋白酶（MMPs）（MMP1、MMP2 和 MMP9）的产生，而已知可阻断 TLR9 信号通路的 MyD88 抑制剂和氯喹抑制了它们的产生。CpG A 还产生了 I 型干扰素（IFN-α 和 IFN-β），而 MyD88 抑制剂抑制了它们的产生。
我们的数据表明，CpG A 诱导的成纤维细胞激活和细胞因子产生是通过 NPDFs 中 TLR9 刺激介导的。用针对 TLR9 或其下游信号通路的抑制剂阻断这一过程可能是 CRSwNP 治疗的一种新方法。
