D L Pham1,2,3, G-Y Ban1, S-H Kim1, Y S Shin1, Y-M Ye1, Y-J Chwae4, H-S Park1,2. 1. Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea. 2. Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Korea. 3. Faculty of Medicine, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Viet Nam. 4. Department of Microbiology, Ajou University School of Medicine, Suwon, Korea.
Abstract
BACKGROUND: Autophagy and neutrophil extracellular DNA traps (NETs) are implicated in asthma; however, their roles in asthma pathogenesis have not been elucidated. OBJECTIVES: 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). METHODS: 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). RESULTS: 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. CONCLUSIONS AND CLINICAL RELEVANCE: 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.
BACKGROUND: Autophagy and neutrophil extracellular DNA traps (NETs) are implicated in asthma; however, their roles in asthma pathogenesis have not been elucidated. OBJECTIVES: 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). METHODS: 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). RESULTS: 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. CONCLUSIONS AND CLINICAL RELEVANCE: 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.
Authors: Marrah E Lachowicz-Scroggins; Eleanor M Dunican; Annabelle R Charbit; Wilfred Raymond; Mark R Looney; Michael C Peters; Erin D Gordon; Prescott G Woodruff; Emma Lefrançais; Brenda R Phillips; David T Mauger; Suzy A Comhair; Serpil C Erzurum; Mats W Johansson; Nizar N Jarjour; Andrea M Coverstone; Mario Castro; Annette T Hastie; Eugene R Bleecker; Merritt L Fajt; Sally E Wenzel; Elliot Israel; Bruce D Levy; John V Fahy Journal: Am J Respir Crit Care Med Date: 2019-05-01 Impact factor: 21.405
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Authors: Kristin M Hudock; Margaret S Collins; Michelle Imbrogno; John Snowball; Elizabeth L Kramer; John J Brewington; Kandace Gollomp; Cormac McCarthy; Alicia J Ostmann; Elizabeth J Kopras; Cynthia R Davidson; Anusha Srdiharan; Paritha Arumugam; Shaon Sengupta; Yan Xu; G Scott Worthen; Bruce C Trapnell; John Paul Clancy Journal: Am J Physiol Lung Cell Mol Physiol Date: 2020-03-11 Impact factor: 5.464