Am. J. Respir. Cell Mol. Biol.,
Volume 19, Number 3, September, 1998 357-365
Ozone Alters the Distribution of 
1 Integrins in Cultured Primate
Bronchial Epithelial Cells
Abdallah J.
Jabbour,
Leonard C.
Altman,
Thomas N.
Wight,
and
Daniel L.
Luchtel
Department of Environmental Health; Division of Allergy and Infectious Diseases; and Department of Pathology,
Department of Medicine, University of Washington, Seattle, Washington
The effects of 0.5 ppm ozone exposure for 6 h on the synthesis and distribution of 
1 integrins were examined in bronchial epithelial cells cultured at an air-cell interface. Ozone exposure damaged cilia and
caused significant cell loss. Immunocytochemical localization and quantification of the 1 subunit in the
remaining attached cells using scanning laser cytometry demonstrated time-dependent changes in 1 distribution in response to ozone. Although no changes were detected immediately after exposure, 1 immunoreactivity increased 23 ± 5% and 66 ± 6% at 6 and 24 h, respectively. The increased immunostaining
was localized at the apical surfaces and, to a lesser extent, at cell-cell contacts of cultured cells. Furthermore, integrin redistribution was not due to increased messenger RNA (mRNA) levels and protein synthesis because levels of 1 mRNA and newly synthesized 1 protein did not change after ozone exposure.
However, immunoprecipitation analysis of 1 integrins in lysates from equal numbers of cells showed that
ozone-exposed cells contained 90 ± 15% more total 1 subunit at 24 h after exposure. In addition, our results demonstrated the presence of the 
51 integrin complex in bronchial epithelial cells and that the detergent-soluble amount of its associated 1 subunit increased 60 ± 10% in lysates of ozone-exposed cells.
In conclusion, ozone altered cellular distribution of 1 integrins in the remaining attached cells subsequent to cell injury and loss. The changes in 1 distribution might be due to increased detergent extractibility of
1 integrins rather than a real increase in the synthesis of 1 integrins.
