title: Role of Neutrophil Extracellular Traps in Asthma and Chronic Obstructive Pulmonary Disease.
abstract: OBJECTIVE
  Asthma and chronic obstructive pulmonary disease (COPD) are representative chronic inflammatory airway diseases responsible for a considerable burden of disease. In this article, we reviewed the relationship between neutrophil extracellular traps (NETs) and chronic inflammatory airway diseases.
  
  
  METHODS
  Articles published up to January 1, 2017, were selected from the PubMed, Ovid Medline, Embase databases, with the keywords of "asthma" or "pulmonary disease, chronic obstructive", "neutrophils" and "extracellular traps."
  
  
  METHODS
  Articles were obtained and reviewed to analyze the role of NETs in asthma and COPD.
  
  
  RESULTS
  NETs are composed of extracellular DNA, histones, and granular proteins, which are released from activated neutrophils. Multiple studies have indicated that there are a large amount of NETs in the airways of asthmatics and COPD patients. NETs can engulf and kill invading pathogens in the host. However, disordered regulation of NET formation has shown to be involved in the development of asthma and COPD. An overabundance of NETs in the airways or lung tissue could cause varying degrees of damage to lung tissues by inducing the death of human epithelial and endothelial cells, and thus resulting in impairing pulmonary function and accelerating the progress of the disease.
  
  
  CONCLUSIONS
  Excessive NETs accumulate in the airways of asthmatics and COPD patients. Although NETs play an essential role in the innate immune system against infection, excessive components of NETs can cause lung tissue damage and accelerate disease progression in asthmatics and COPD patients. These findings suggest that administration of NETs could be a novel approach to treat asthma and COPD. Mechanism studies, clinical practice, and strategies to regulate neutrophil activation or directly interrupt NET function in asthmatics and COPD patients are desperately needed.
authors.affiliation: Department of Respiratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuang 610041, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Liu
authors.affiliation: Department of Respiratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuang 610041, China.
authors.forename: Fa-Ping
authors.initials: FP
authors.lastname: Wang
authors.affiliation: Department of Respiratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuang 610041, China.
authors.forename: Geng
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Respiratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuang 610041, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Mao
mesh_terms: D000818:Animals; D001249:Asthma / Q000378:metabolism* / Q000473:pathology; D065206:Extracellular Traps / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D009504:Neutrophils / Q000378:metabolism* / Q000473:pathology; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism* / Q000473:pathology