Calcium-dependent regulation of NF-(kappa)B activation in cystic fibrosis airway epithelial cells.
Dysregulation of nuclear factor kappa B (NF-(kappa)B) and increased Ca(2+) signals have been reported in airway epithelial cells of patients with cystic fibrosis (CF). The hypothesis that Ca(2+) signaling may regulate NF-(kappa)B activation was tested in a CF bronchial epithelial cell line (IB3-1, CFTR genotype DeltaF508/W1282X) and compared to the CFTR-corrected epithelial cell line S9 using fluorescence microscopy to visualized in situ NF-(kappa)B activation at the single cell level. Upon stimulation with IL-1beta,we observed a slow but prolonged [Ca(2+)](i) increase (up to 10 min) in IB3-1 cells compared to S9 cells. The IL-1beta-induced [Ca(2+)](i) response was accompanied by an activation of NF-(kappa)B in IB3-1 but not in S9 cells. Pretreatment of IB3-1 cells with the ER Ca(2+) pump inhibitor thapsigargin inhibited the IL-1beta-induced [Ca(2+)](i) response. Treatment with either the calcium chelator BAPTA or an inhibitor of I(kappa)Balpha phosphorylation (digitoxin) led to a drastic [Ca(2+)](i) decrease accompanied by an inhibition of NF-(kappa)B activation of IL-1beta-stimulated IB3-1 cells in comparison to untreated cells. In IB3-1 cells cultured at low temperature (26 degrees C) for 16 h, the IL-1beta-induced [Ca(2+)](i) response was inhibited and no significant NF-(kappa)B activation was observed. To our knowledge, this is the first report of visualization of the Ca(2+)-mediated activation of NF-(kappa)B in individual living airway epithelial cells. Our results support the concept that [Ca(2+)](i) is a key regulator of NF-(kappa)B activation in CF airway epithelial cells.
Tabary
Olivier
O
Inserm UMR 719, Université Pierre et Marie Curie, Hôpital Saint-Antoine, Bât. Kourilsky 184, Rue du Fg Saint-Antoine 75571, Paris, France.
Boncoeur
Emilie
E
de Martin
Rainer
R
Pepperkok
Rainer
R
Clément
Annick
A
Schultz
Carsten
C
Jacquot
Jacky
J
D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D002460:Cell Line; D002614:Chelating Agents / Q000378:metabolism; D003550:Cystic Fibrosis / Q000378:metabolism*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics / Q000378:metabolism; D004074:Digitoxin / Q000378:metabolism; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020545:Respiratory Mucosa / Q000166:cytology*
D002614:Chelating Agents; D004791:Enzyme Inhibitors; D007375:Interleukin-1; D016328:NF-kappa B; D011993:Recombinant Fusion Proteins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D004533:Egtazic Acid; D004074:Digitoxin; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium