Src signaling links mediators of inflammation to Cx43 gap junction channels in primary and transformed CFTR-expressing airway cells.
Dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) is associated with recurrent pulmonary infections and inflammation. We previously reported that tumor necrosis factor (TNF)-alpha decreases gap junction connectivity in cell lines derived from the airway epithelium of non-cystic fibrosis (non-CF) subjects, a mechanism that was defective in cells derived from CF patients, and identified the tyrosine kinase c-Src as a possible bridge between TNF-alpha and Cx43. To examine whether this modulation also takes place in primary epithelial cells, the functional expression of Cx43 was studied in non-CF and CF airway cells, obtained from surgical polypectomies and turbinectomies, which were grown either on culture dishes or permeable filters. Expression of Cx43 was detected by immunofluorescence on cells grown under both culture conditions. Non-CF and CF airway cells also showed intercellular diffusion of Lucifer Yellow. Dye coupling was rapidly abolished in non-CF cells in the presence of TNF-alpha, lipopolysaccharide and lysophosphatidic acid, and could be prevented by tyrphostin47, an inhibitor of Src tyrosine kinases. This down-regulation, however, was not detected in CF airway cells. These data indicate that CFTR dysfunction is associated with altered Src signaling, resulting in the persistence of gap junction connectivity in primary and transformed CF airway cells.
Huang
Song
S
Laboratory of Clinical Investigation III, Department of Pediatrics, Geneva University Hospitals, Geneva, Switzerland.
Jornot
Lan
L
Wiszniewski
Ludovic
L
Rochat
Thierry
T
Suter
Susanne
S
Lacroix
Jean-Silvain
JS
Chanson
Marc
M
D051242:Caveolin 1; D022461:Caveolins / Q000378:metabolism; D002450:Cell Communication / Q000187:drug effects; D002478:Cells, Cultured; D018031:Connexin 43 / Q000378:metabolism*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000378:metabolism*; D006801:Humans; D018836:Inflammation Mediators / Q000494:pharmacology*; D007546:Isoquinolines / Q000737:chemistry; D008070:Lipopolysaccharides / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism; D020545:Respiratory Mucosa / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D020032:Tyrphostins / Q000494:pharmacology; D019061:src-Family Kinases / Q000378:metabolism*
C505032:CFTR protein, human; D051242:Caveolin 1; D022461:Caveolins; D018031:Connexin 43; D018836:Inflammation Mediators; D007546:Isoquinolines; D008070:Lipopolysaccharides; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D020032:Tyrphostins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; C017475:lucifer yellow; D019061:src-Family Kinases