title: Glucocorticoids do not alter peptidase expression on a human bronchial epithelial cell line.
abstract: Respiratory epithelial cell surface neutral endopeptidase 24.11 (NEP-24.11) degrades proinflammatory peptides, and it has been suggested that glucocorticoids may reduce airway inflammation, in part, by upregulation of NEP-24.11. Despite the potential importance of the epithelium as a metabolic barrier, little is known regarding what other peptidases may be present on the epithelial cell surface. Using an immortalized bronchial epithelial cell line (BEAS-2B), we have shown that human epithelial cells express no detectable angiotensin-converting enzyme, carboxypeptidase N, or dipeptidyl(amino)peptidase IV, but express significant levels of aminopeptidase M (AmM), as well as NEP-24.11. The presence of these enzymes was demonstrated via their degradation of biologically active peptides and by flow cytometry. Exposure of cells to the glucocorticoid budesonide (10(-7) M) for up to 5 days did not markedly alter the expression of NEP-24.11 or AmM, as assessed by flow cytometry, nor did glucocorticoid treatment modify rates of peptide hydrolysis by NEP-24.11 or AmM. Thus, BEAS-2B cells have both AmM and NEP-24.11 on their surface, and expression of these enzymes is not altered by glucocorticoids.
authors.affiliation: Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: D
authors.initials: D
authors.lastname: Proud
authors.forename: M C
authors.initials: MC
authors.lastname: Subauste
authors.forename: P E
authors.initials: PE
authors.lastname: Ward
mesh_terms: D000626:Aminopeptidases / Q000378:metabolism; D001920:Bradykinin / Q000378:metabolism; D001980:Bronchi / Q000187:drug effects / Q000378:metabolism*; D019819:Budesonide; D018826:CD13 Antigens; D002461:Cell Line, Transformed; D004745:Enkephalins / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D005434:Flow Cytometry; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D007609:Kallidin / Q000378:metabolism; D015260:Neprilysin / Q000378:metabolism*; D011282:Pregnenediones / Q000494:pharmacology; D013373:Substance P / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D004745:Enkephalins; D005938:Glucocorticoids; D011282:Pregnenediones; D013373:Substance P; D007609:Kallidin; D019819:Budesonide; D000626:Aminopeptidases; D018826:CD13 Antigens; D015260:Neprilysin; D001920:Bradykinin