title: Functional characteristics of bronchial epithelium obtained by brushing from asthmatic and normal subjects.
abstract: Airways epithelial cells may be involved in the pathogenesis of asthma, but their role remains to be determined. Epithelial cells can release large amounts of 15-hydroxy-eicosatetranoic acid (15-HETE) and smaller amounts of prostaglandin E2 (PGE2) as well as fibronectin, a mediator involved in epithelial repair after injury. Epithelial cells obtained after bronchial brushing of 16 asthmatic (age 38 +/- 5 yr) and 11 normal subjects (age 36 +/- 5 yr) were studied. The percentage of epithelial cells was assessed by immunocytochemistry using an anti-cytokeratin antibody. The viability of the cells was assessed by trypan blue exclusion. The release of 15-HETE PGE2 and fibronectin was studied in resting cells and after A23187 calcium ionophore stimulation. Epithelial cells always comprised more than 86% of cells recovered, and the viability of epithelial cells was significantly (p < 0.001, Mann-Whitney U test) greater in normal subjects (54 +/- 5%) compared with asthmatic subjects (13 +/- 1%). The release of 15-HETE and fibronectin by resting epithelial cells was significantly greater in asthmatics (p < 0.05, Mann-Whitney U test) than in normal subjects. A23187 significantly (p < 0.05, Wilcoxon W test) increased the release of 15-HETE and fibronectin. There was no significant difference in the release of PGE2 by resting cells from either asthmatics or normal subjects, but challenge with A23187 induced a significant (p < 0.03, Wilcoxon W test) increase in PGE2 from cells of asthmatics but not from cells of normal subjects. This study shows that epithelial cells are activated and less viable in asthma and suggests a role for these cells in asthma.
authors.affiliation: Service des Maladies Respiratoires, Hôpital Aiguelongue, Montpellier, France.
authors.forename: A M
authors.initials: AM
authors.lastname: Campbell
authors.forename: P
authors.initials: P
authors.lastname: Chanez
authors.forename: A M
authors.initials: AM
authors.lastname: Vignola
authors.forename: J
authors.initials: J
authors.lastname: Bousquet
authors.forename: I
authors.initials: I
authors.lastname: Couret
authors.forename: F B
authors.initials: FB
authors.lastname: Michel
authors.forename: P
authors.initials: P
authors.lastname: Godard
mesh_terms: D000328:Adult; D000420:Albuterol / Q000494:pharmacology; D001249:Asthma / Q000209:etiology / Q000503:physiopathology*; D001980:Bronchi / Q000166:cytology / Q000187:drug effects / Q000503:physiopathology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D001999:Bronchoscopy; D000001:Calcimycin / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D015232:Dinoprostone / Q000032:analysis; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000503:physiopathology; D005336:Fiber Optic Technology; D005353:Fibronectins / Q000032:analysis / Q000187:drug effects; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000032:analysis
chemical_list: D005353:Fibronectins; D006893:Hydroxyeicosatetraenoic Acids; D000001:Calcimycin; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D015232:Dinoprostone; D000420:Albuterol