TY - JOUR
T1 - Ozone activates airway nerves via the selective stimulation of TRPA1 ion channels
AU - Taylor-Clark, Thomas E.
AU - Undem, Bradley J.
PY - 2010/2
Y1 - 2010/2
N2 - Inhalation of ozone is a major health risk in industrialized nations. Ozone can impair lung function and induce respiratory symptoms through sensory neural-mediated pathways, yet the specific interaction of ozone with airway sensory nerves has yet to be elucidated. Here we demonstrate, using a vagally innervated ex vivo tracheal-lung mouse preparation, that ozone selectively and directly evokes action potential discharge in a subset of nociceptive bronchopulmonary nerves, namely slow conducting C-fibres. Sensitivity to ozone correlated with the transient receptor potential (TRP) A1 agonist, cinnamaldehyde, with ozone having no effect on cinnamaldehyde-insensitive fibres. C-fibre responses to ozone were abolished by ruthenium red (TRP inhibitor). Ozone also stimulated a subset of nociceptive sensory neurones isolated from vagal ganglia of wild-type mice, but failed to activate neurones isolated from transient receptor potential ankyrin 1 (TRPA1) knockout mice. Ozone activated HEK293 cells transfected with TRPA1, but failed to activate non-transfected HEK293 or HEK293 transfected with the capsaicin-sensitive transient receptor potential vanilloid 1 (TRPV1) channel. Thus, ozone is not an indiscriminate neuronal activator, but rather it potently and selectively activates a subset of airway C-fibres by directly stimulating TRPA1.
AB - Inhalation of ozone is a major health risk in industrialized nations. Ozone can impair lung function and induce respiratory symptoms through sensory neural-mediated pathways, yet the specific interaction of ozone with airway sensory nerves has yet to be elucidated. Here we demonstrate, using a vagally innervated ex vivo tracheal-lung mouse preparation, that ozone selectively and directly evokes action potential discharge in a subset of nociceptive bronchopulmonary nerves, namely slow conducting C-fibres. Sensitivity to ozone correlated with the transient receptor potential (TRP) A1 agonist, cinnamaldehyde, with ozone having no effect on cinnamaldehyde-insensitive fibres. C-fibre responses to ozone were abolished by ruthenium red (TRP inhibitor). Ozone also stimulated a subset of nociceptive sensory neurones isolated from vagal ganglia of wild-type mice, but failed to activate neurones isolated from transient receptor potential ankyrin 1 (TRPA1) knockout mice. Ozone activated HEK293 cells transfected with TRPA1, but failed to activate non-transfected HEK293 or HEK293 transfected with the capsaicin-sensitive transient receptor potential vanilloid 1 (TRPV1) channel. Thus, ozone is not an indiscriminate neuronal activator, but rather it potently and selectively activates a subset of airway C-fibres by directly stimulating TRPA1.
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U2 - 10.1113/jphysiol.2009.183301
DO - 10.1113/jphysiol.2009.183301
M3 - Article
C2 - 20008466
AN - SCOPUS:75649104334
SN - 0022-3751
VL - 588
SP - 423
EP - 433
JO - Journal of Physiology
JF - Journal of Physiology
IS - 3
ER -