title: Modulation of cadherin and catenins expression by tumor necrosis factor-alpha and dexamethasone in human bronchial epithelial cells.
abstract: Asthma is an inflammatory disease, and the epithelial mesenchymal unit appears to be of importance in regulating the disease mechanisms. Cell-cell adhesion plays an important role in tissue morphogenesis and homeostasis and is commonly mediated by cadherins, a family of Ca(2+)-dependent transmembrane adhesion receptors. The cadherin family is involved in control of the cellular architecture. Proinflammatory cytokines such as tumor necrosis factor (TNF)-alpha are involved in asthma and may interfere with epithelial integrity. In the present study, we investigated the role of TNF-alpha and dexamethasone on the expression of E-cadherin, beta-catenin, and gamma-catenin. We used two bronchial epithelial cell models: primary small airway epithelial cell cultures and primary culture obtained from human bronchial tubes. After 48 h of TNF-alpha stimulation with or without dexamethasone expression of E-cadherin, beta-catenin and gamma-catenin were analyzed using Western blot analysis and immunofluorescence. This study showed a decrease in the expression of adhesion molecules in both epithelial cell cultures after stimulation. Dexamethasone and anti-TNF-alpha inhibited this effect. In unstimulated cells, E-cadherin and beta- and gamma-catenin expression was membranous, expressed only on the lateral cell wall with minimal cytoplasmic expression. Immunoreactivity was cytoplasmic in stimulated cells. We demonstrated, using Western blot analysis and immunofluorescence, that proinflammatory cytokines could be responsible for structural damage to the epithelium and that this process was potentially reversed by steroids.
authors.affiliation: Clinique des Maladies Respiratoires, Hôpital Arnaud de Villeneuve, Montpellier, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Carayol
authors.forename: Alison
authors.initials: A
authors.lastname: Campbell
authors.forename: Isabelle
authors.initials: I
authors.lastname: Vachier
authors.forename: Brigitte
authors.initials: B
authors.lastname: Mainprice
authors.forename: Jean
authors.initials: J
authors.lastname: Bousquet
authors.forename: Philippe
authors.initials: P
authors.lastname: Godard
authors.forename: Pascal
authors.initials: P
authors.lastname: Chanez
mesh_terms: D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D015153:Blotting, Western; D001980:Bronchi / Q000166:cytology / Q000378:metabolism*; D015820:Cadherins / Q000096:biosynthesis*; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000096:biosynthesis*; D051180:Desmoplakins; D003907:Dexamethasone / Q000494:pharmacology*; D004847:Epithelial Cells / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006801:Humans; D015534:Trans-Activators; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D051176:beta Catenin; D051185:gamma Catenin
chemical_list: D000893:Anti-Inflammatory Agents; C495270:CTNNB1 protein, human; D015820:Cadherins; D003598:Cytoskeletal Proteins; D051180:Desmoplakins; C495292:JUP protein, human; D015534:Trans-Activators; D014409:Tumor Necrosis Factor-alpha; D051176:beta Catenin; D051185:gamma Catenin; D003907:Dexamethasone