Neutrophil extracellular traps in nasal secretions of patients with stable and exacerbated chronic rhinosinusitis and their contribution to induce chemokine secretion and strengthen the epithelial barrier

Abstract

Background: Neutrophil extracellular traps (NETs) participate in innate immunity by trapping microorganisms. Their pathophysiological implications have not been defined in chronic rhinosinusitis (CRS). Objective: We investigated the presence of NETs in nasal secretion of patients with stable or exacerbated CRS and evaluated whether NETs participate in the secretion of chemokines in sinonasal epithelial cells, the epithelial permeability, and transendothelial leucocyte migration, and elucidate whether NETs are released by macrolides and dexamethasone. Methods: The presence of NETs in nasal secretion and the release of NETs from neutrophils stimulated with macrolides or dexamethasone were evaluated by dsDNA Assay kit and fluorescence microscope. The chemokine secretion, epithelial permeability, and transendothelial leucocyte migration were measured in cultured cells incubated with NETs, the supernatant of unstimulated neutrophils (unstim), NETs inhibitor (DPI), or H3Cit, where the expression of junctional complex proteins and ICAM-1 was evaluated by real-time PCR, Western blots, and confocal microscope. Results: The amount of NETs and NETs-forming neutrophils in nasal secretion increased in exacerbated CRS. Epithelial cells treated with NETs or H3Cit secreted chemokines and showed decreased permeability associated with up-regulated junctional complex proteins. Increased transendothelial leucocyte migration associated with up-regulated ICAM-1 was noted in endothelial cells treated with NETs or H3Cit.These findings were not found in cells treated with unstim, or DPI. NETs were released by macrolides, but not by dexamethasone. Conclusions and Clinical Relevance: NETs formation increased in exacerbated CRS,inducing chemokine secretion, strengthening the epithelial barrier, and promoting the neutrophils infiltration. Therefore, the release of NETs in CRS might be beneficial or detrimental to CRS patients. K E Y W O R D Schemokines, dexamethasone, epithelial permeability, macrolides, neutrophil extracellular traps, transendothelial leucocyte migration

Rethinking neutrophils and eosinophils in chronic rhinosinusitis

“…Neutrophil extracellular traps (NETs), generally consisting of neutrophil DNA associated with granule proteins, are present in secretions of CRSwNP and at subepithelial regions in tissue of both patients with CRSsNP and patients with CRSwNP. 13,[97][98][99] The pathway of NET formation is highly dependent on the individual micro-organism identity, pathogen size, and additional stimuli. [99][100][101] CLCs evoke neutrophil death in vitro, making it likely that CLCs in tissue and secretions might contribute to tissue damage in patients with CRS.…”

Extracellular traps as an important part of the pathogenesis in chronic rhinosinusitis

“…В России, по данным некоторых авторов, средняя распространенность заболевания составляет 16,42±10,89% [2]. В последние годы появляется все больше информации о влиянии уникального механизма иммунного ответа -образования внеклеточных ловушек -на течение многих хронических заболеваний, включая ХРС [3][4][5][6].…”

“…В большинстве случаев в клинической практике используется классификация ХРС согласно такому фенотипическому признаку, как наличие полипов. На основании этого условия ХРС подразделяется на полипозный и без полипов [1,3,5,6].…”

Developments allergy in 2019 through the eyes of Clinical and Experimental Allergy, Part II clinical allergy

“…Hwang and colleagues investigated the presence of neutrophil extracellular traps (NETs) in nasal secretions from patients with chronic rhinosinusitis during stable disease and exacerbation. 87…”

“…Although the role of neutrophils and their activation status in the lower airways has been linked to more severe asthma, to date, the role of neutrophils in influencing severity of chronic rhinosinusitis has not been studied. Hwang and colleagues investigated the presence of neutrophil extracellular traps (NETs) in nasal secretions from patients with chronic rhinosinusitis during stable disease and exacerbation 87 . The role of NETs in secreting chemokines and affecting nasal epithelial permeability was assessed.…”