GLUCOCORTICOID RECEPTOR LOCALIZATION IN NORMAL AND ASTHMATIC LUNG

The localization and distribution of the human glucocorticoid receptor (CR) mRNA and protein was investigated in human lung obtained from tr ansplant donors and recipients by in situ hybridization, RNA blot anal ysis, immunolocalization, and Western analysis. Subjects were either n onasthmatic or had mild asthma requiring only beta(2)-agonists. No dif ference in amount of CR mRNA was found in total RNA isolated from nona sthmatic or asthmatic donor lung. In situ hybridization showed the hig hest concentration of GR mRNA in the alveolar walls and vascular endot helium and smooth muscle, with lesser amounts in the airway epithelium and smooth muscle. There was no change in the level or sites of expre ssion of CR mRNA between normal and asthmatic subjects. Immunolocaliza tion of GR confirmed the in situ hybridization data. There was no chan ge in the level or sites of expression of GR, in either the lung or ai rway, between normal and asthmatic subjects, Immunolocalization of GR in bronchial biopsies from two normal and asthmatic subjects confirmed the localization and distribution of GR. Western analysis and mobilit y shift assays confirmed no differences in GR levels between the two s ubject groups. The localization of CR mRNA and protein to specific cel l types within lung and airway will make it possible to study the cell ular targets of glucocorticoid therapy in inflammatory lung diseases s uch as asthma.