Expression of icam-1 in airway epithelium following acute ozone
exposure in the mouse .
Takahashi, Nobuyoshi, Xiao-Ying Yu, Brian H. Schofield, Steven R.
Kleeberger, Alan L. Scott, Shizuo Hasegawa, and Ernst Wm. Spannhake.
Department of Environmental Health Sciences and Department of
Molecular Microbiology and Immunology, The Johns Hopkins School of
Hygiene and Public Health, and Department of Internal Medicine,
Division of Pulmonary Medicine, Tsukuba University, Ibaraki 305,
Japan
APStracts 2:0285A, 1995.
We investigated the time course and regional distribution of the
expression of intercellular adhesion molecule-1 (ICAM-1) on airway
epithelial cells and the polymorphonuclear leukocyte (PMN)
inflammatory response in the lung following acute exposure to ozone
(O3). C57BL/6J mice were exposed to air or 2 ppm O3 for 3 h and
sacrificed immediately or 3, 6, 9 or 21 h after exposure. Expression
of ICAM-1 was examined by immunohistochemical staining of frozen
sections. PMN influx was evaluated by lavage and by histochemical
staining of myeloperoxidase (MPO) and measurement of tissue MPO
activity. ICAM-1 expression exhibited regional selectivity and
temporal patterns that were unique to each region. Up-regulation of
ICAM-1 expression on the epithelial cells in the trachea and, to a
lesser extent in the lobar and segmental bronchi, was observed by 3-9
h following exposure and remained present at 21 h. Enhanced ICAM-1
expression in bronchioles and terminal bronchiole/alveolar duct
regions was evident earlier (immediately to 3 h after exposure), but
returned to baseline levels by 21 and 9 h, respectively. Maximal
ICAM-1 expression and PMN influx in the lung parenchyma were
concurrently observed at 3 h, followed by transepithelial migration
of PMNs to the airway lumen. These results demonstrate regional
variations in airway inflammatory activity and are supportive of the
notion that up-regulation of ICAM-1 on the airway epithelium may play
a role in local regulation of PMN influx to the airways following
acute O3 exposure.
Received 23 March 1994; accepted in final form 14 June 1995.
APS Manuscript Number A285-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 11 July 1995.