Extracellular DNA, Neutrophil Extracellular Traps, and Inflammasome Activation in Severe Asthma

M. Lachowicz-Scroggins,E. Dunican,A. Charbit,W. Raymond,M. Looney,M. Peters,Erin D. Gordon,P. Woodruff,Emma Lefrançais,B. Phillips,D. Mauger,S. Comhair,S. Erzurum,M. Johansson,N. Jarjour,A. Coverstone,M. Castro,A. Hastie,E. Bleecker,M. Fajt,S. Wenzel,E. Israel,B. Levy,J. Fahy

Published 2019 in American Journal of Respiratory and Critical Care Medicine

ABSTRACT

Rationale: Extracellular DNA (eDNA) and neutrophil extracellular traps (NETs) are implicated in multiple inflammatory diseases. NETs mediate inflammasome activation and IL‐1&bgr; secretion from monocytes and cause airway epithelial cell injury, but the role of eDNA, NETs, and IL‐1&bgr; in asthma is uncertain. Objectives: To characterize the role of activated neutrophils in severe asthma through measurement of NETs and inflammasome activation. Methods: We measured sputum eDNA in induced sputum from 399 patients with asthma in the Severe Asthma Research Program‐3 and in 94 healthy control subjects. We subdivided subjects with asthma into eDNA‐low and ‐high subgroups to compare outcomes of asthma severity and of neutrophil and inflammasome activation. We also examined if NETs cause airway epithelial cell damage that can be prevented by DNase. Measurements and Main Results: We found that 13% of the Severe Asthma Research Program‐3 cohort is “eDNA‐high,” as defined by sputum eDNA concentrations above the upper 95th percentile value in health. Compared with eDNA‐low patients with asthma, eDNA‐high patients had lower Asthma Control Test scores, frequent history of chronic mucus hypersecretion, and frequent use of oral corticosteroids for maintenance of asthma control (all P values <0.05). Sputum eDNA in asthma was associated with airway neutrophilic inflammation, increases in soluble NET components, and increases in caspase 1 activity and IL‐1&bgr; (all P values <0.001). In in vitro studies, NETs caused cytotoxicity in airway epithelial cells that was prevented by disruption of NETs with DNase. Conclusions: High extracellular DNA concentrations in sputum mark a subset of patients with more severe asthma who have NETs and markers of inflammasome activation in their airways.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-43 of 43 references · Page 1 of 1

CITED BY

Showing 1-100 of 231 citing papers · Page 1 of 3