RRC ID 82625
Author Robinson RK, Birrell MA, Adcock JJ, Wortley MA, Dubuis ED, Chen S, McGilvery CM, Hu S, Shaffer MSP, Bonvini SJ, Maher SA, Mudway IS, Porter AE, Carlsten C, Tetley TD, Belvisi MG.
Title Mechanistic link between diesel exhaust particles and respiratory reflexes.
Journal J Allergy Clin Immunol
Abstract BACKGROUND:Diesel exhaust particles (DEPs) are a major component of particulate matter in Europe's largest cities, and epidemiologic evidence links exposure with respiratory symptoms and asthma exacerbations. Respiratory reflexes are responsible for symptoms and are regulated by vagal afferent nerves, which innervate the airway. It is not known how DEP exposure activates airway afferents to elicit symptoms, such as cough and bronchospasm.
OBJECTIVE:We sought to identify the mechanisms involved in activation of airway sensory afferents by DEPs.
METHODS:In this study we use in vitro and in vivo electrophysiologic techniques, including a unique model that assesses depolarization (a marker of sensory nerve activation) of human vagus.
RESULTS:We demonstrate a direct interaction between DEP and airway C-fiber afferents. In anesthetized guinea pigs intratracheal administration of DEPs activated airway C-fibers. The organic extract (DEP-OE) and not the cleaned particles evoked depolarization of guinea pig and human vagus, and this was inhibited by a transient receptor potential ankyrin-1 antagonist and the antioxidant N-acetyl cysteine. Polycyclic aromatic hydrocarbons, major constituents of DEPs, were implicated in this process through activation of the aryl hydrocarbon receptor and subsequent mitochondrial reactive oxygen species production, which is known to activate transient receptor potential ankyrin-1 on nociceptive C-fibers.
CONCLUSIONS:This study provides the first mechanistic insights into how exposure to urban air pollution leads to activation of guinea pig and human sensory nerves, which are responsible for respiratory symptoms. Mechanistic information will enable the development of appropriate therapeutic interventions and mitigation strategies for those susceptible subjects who are most at risk.
Volume 141(3)
Pages 1074-1084.e9
Published 2018-3-1
DOI 10.1016/j.jaci.2017.04.038
PII S0091-6749(17)30796-0
PMID 28532657
PMC PMC5840514
MeSH Aged Air Pollutants / toxicity* Animals Asthma* / chemically induced Asthma* / metabolism Asthma* / pathology Asthma* / physiopathology Bronchial Spasm* / chemically induced Bronchial Spasm* / metabolism Bronchial Spasm* / pathology Bronchial Spasm* / physiopathology Female Gene Expression Regulation / drug effects* Guinea Pigs Humans Male Mice Middle Aged Particulate Matter / toxicity* Reflex / drug effects* Vehicle Emissions*
IF 10.228
Resource
Mice RBRC01939