Pham D L, Ban G-Y, Kim S-H, Shin Y S, Ye Y-M, Chwae Y-J, Park H-S
Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea.
Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Korea.
Clin Exp Allergy. 2017 Jan;47(1):57-70. doi: 10.1111/cea.12859.
Autophagy and neutrophil extracellular DNA traps (NETs) are implicated in asthma; however, their roles in asthma pathogenesis have not been elucidated.
We compared autophagy and NET production levels from peripheral blood neutrophils (PBNs) of patients with severe asthma (SA) and non-severe asthma (NSA). Additionally, we investigated the inflammatory effects of NETs on human airway epithelial cells (AECs) and peripheral blood eosinophils (PBEs).
Peripheral blood neutrophils from patients with SA (n = 30) and NSA (n = 38) were treated with interleukin (IL)-8 (100 ng/mL). Autophagy (light chain 3-II expression) and NET production levels were evaluated by Western blot, immunofluorescence microscopy, and PicoGreen assay. The effects of NETs on AECs were assessed by investigating cell death, cell detachment, expression of occludin and claudin-1, and IL-8 production; the effects of NETs on PBEs were examined by investigating the activation and release of eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN).
Untreated and IL-8-treated PBNs from the SA group produced higher autophagy and NET levels compared with those from the NSA group (P < 0.01). IL-8 increased autophagy and NET levels in PBNs from the SA group, but not from the NSA group. NET levels were correlated with autophagy levels in PBNs (P < 0.001). IL-8-induced NET production levels negatively were correlated with FEV1/FVC (r = -0.700, P = 0.016). NETs induced cell death, detachment, degradation of occludin and claudin-1, and IL-8 production from AECs. Higher levels of NET-induced ECP and EDN were released from PBEs in SA compared with NSA groups.
Neutrophil autophagy and NETs could enhance asthma severity by damaging airway epithelium and triggering inflammatory responses of AECs and PBEs. Modulating neutrophil autophagy and NET production may be a new target therapy for SA.
自噬和中性粒细胞胞外DNA陷阱（NETs）与哮喘有关；然而，它们在哮喘发病机制中的作用尚未阐明。
我们比较了重度哮喘（SA）和非重度哮喘（NSA）患者外周血中性粒细胞（PBNs）的自噬和NET生成水平。此外，我们研究了NETs对人气道上皮细胞（AECs）和外周血嗜酸性粒细胞（PBEs）的炎症影响。
用白细胞介素（IL）-8（100 ng/mL）处理SA患者（n = 30）和NSA患者（n = 38）的外周血中性粒细胞。通过蛋白质免疫印迹法、免疫荧光显微镜和PicoGreen检测法评估自噬（轻链3-II表达）和NET生成水平。通过研究细胞死亡、细胞脱离、闭合蛋白和Claudin-1的表达以及IL-8的产生来评估NETs对AECs的影响；通过研究嗜酸性粒细胞阳离子蛋白（ECP）和嗜酸性粒细胞衍生神经毒素（EDN）的激活和释放来检测NETs对PBEs的影响。
与NSA组相比，SA组未经处理和经IL-8处理的PBNs产生更高的自噬和NET水平（P < 0.01）。IL-8增加了SA组PBNs的自噬和NET水平，但未增加NSA组的。NET水平与PBNs中的自噬水平相关（P < 0.001）。IL-8诱导的NET生成水平与第一秒用力呼气容积/用力肺活量（FEV1/FVC）呈负相关（r = -0.700，P = 0.016）。NETs诱导AECs细胞死亡、脱离、闭合蛋白和Claudin-1降解以及IL-8产生。与NSA组相比，SA组中NET诱导的PBEs释放的ECP和EDN水平更高。
中性粒细胞自噬和NETs可通过损伤气道上皮并触发AECs和PBEs的炎症反应来加重哮喘严重程度。调节中性粒细胞自噬和NET生成可能是SA的一种新的靶向治疗方法。
