Expression of ICAM-1 in airway epithelium after acute ozone exposure in the mouse.
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 after acute exposure to ozone (O3). C57BL/6J mice were exposed to air or 2 ppm O3 for 3 h and killed 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. Upregulation of ICAM-1 expression on the epithelial cells in the trachea, and to a lesser extent in the lobar and segmental bronchi, was observed 3-9 h after 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 upregulation of ICAM-1 on the airway epithelium may play a role in local regulation of PMN influx to the airways after acute O3 exposure.
Takahashi
N
N
Department of Environmental Health Sciences, Johns Hopkins School of Hygiene and Public Health, Baltimore, Maryland 21205, USA.
Yu
X Y
XY
Schofield
B H
BH
Kleeberger
S R
SR
Scott
A L
AL
Hasegawa
S
S
Spannhake
E W
EW
D000280:Administration, Inhalation; D000818:Animals; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D018799:Intercellular Adhesion Molecule-1 / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D010083:Oxidants, Photochemical / Q000494:pharmacology*; D010126:Ozone / Q000494:pharmacology*; D009195:Peroxidase / Q000187:drug effects / Q000378:metabolism; D012137:Respiratory System / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology
D010083:Oxidants, Photochemical; D018799:Intercellular Adhesion Molecule-1; D010126:Ozone; D009195:Peroxidase