GLUCOCORTICOID RECEPTORS IN BRONCHIAL EPITHELIAL-CELLS IN ASTHMA

The expression of the glucocorticoid receptor (GR) in untreated or in steroid-dependent asthmatic patients is poorly understood. We therefor e studied GR mRNA and protein levels in bronchial biopsies obtained fr om seven untreated asthmatic patients, seven control volunteers, and s even patients with chronic bronchitis. We also studied in bronchial ep ithelial cells obtained by brushing from 13 untreated asthmatics, 18 s teroid-dependent asthmatics, 11 control volunteers, and 12 patients wi th chronic bronchitis, CR and heat shock protein 90 kD (hsp90) mRNA as well as the immunoreactivity of CR, intercellular adhesion molecule ( ICAM-1), and granulocyte macrophage-colony-stimulating factor (GM-CSF) . GR mRNA and protein level was similar in all subject groups in both biopsies and bronchial epithelial cells. Hsp90 mRNA level was also sim ilar in all subject groups. ICAM-1 expression was significantly increa sed in bronchial epithelial cells from untreated asthmatics, but ICAM- 1 was not expressed in those from steroid-dependent asthmatic patients . GM-CSF expression was significantly increased in bronchial epithelia l cells from untreated and steroid-dependent asthmatic patients. GR ex pression within the airways is unaltered by oral long-term steroid tre atment in asthma, but the expression of some but not all specific mark ers for asthma is modified by oral steroid.