Effects of cystic fibrosis transmembrane conductance regulator and DeltaF508CFTR on inflammatory response, ER stress, and Ca2+ of airway epithelia.
We tested whether cystic fibrosis (CF) airway epithelia have larger innate immune responses than non-CF or cystic fibrosis transmembrane conductance regulator (CFTR)-corrected cells, perhaps resulting from ER stress due to retention of DeltaF508CFTR in the endoplasmic reticulum (ER) and activation of cytosolic Ca(2+) (Ca(i)) and nuclear factor (NF)-kappaB signaling. Adenovirus infections of a human CF (DeltaF508/DeltaF508) nasal cell line (CF15) provided isogenic comparisons of wild-type (wt) CFTR and DeltaF508CFTR. In the absence of bacteria, there were no or only small differences among CF15, CF15-lacZ (beta-galactosidase-expressing), CF15-wtCFTR (wtCFTR-corrected), and CF15-DeltaF508CFTR (to test ER retention of DeltaF508CFTR) cells in NF-kappaB activity, interleukin (IL)-8 secretion, Ca(i) responses, and ER stress. Non-CF and CF primary cultures of human bronchial epithelial cells (HBE) secreted IL-8 equivalently. Upon infection with Pseudomonas aeruginosa (PA) or flagellin (key activator for airway epithelia), CF15, CF15-lacZ, CF15-wtCFTR, and CF15DeltaF508CFTR cells exhibited equal PA binding, NF-kappaB activity, and IL-8 secretion; cells also responded similarly to flagellin when both CFTR (forskolin) and Ca(i) signaling (ATP) were activated. CF and non-CF HBE responded similarly to flagellin + ATP. Thapsigargin (Tg, releases ER Ca(2+)) increased flagellin-stimulated NF-kappaB and ER stress similarly in all cells. We conclude that ER stress, Ca(i), and NF-kappaB signaling and IL-8 secretion were unaffected by wt- or DeltaF508CFTR in control and during exposure to PA, flagellin, flagellin + ATP, or flagellin + ATP + forskolin. Tg, but not wt- or DeltaF508CFTR, triggered ER stress. Previous measurements showing hyperinflammatory responses in CF airway epithelia may have resulted from cell-specific, rather than CFTR- or DeltaF508CFTR-specific effects.
Hybiske
Kevin
K
Dept. of Molecular and Cell Biology, 231 LSA, Univ. of California-Berkeley, Berkeley, CA 94720-3200, USA.
Fu
Zhu
Z
Schwarzer
Christian
C
Tseng
Jill
J
Do
Jiun
J
Huang
Natalie
N
Machen
Terry E
TE
D001980:Bronchi / Q000166:cytology / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D002478:Cells, Cultured; D003550:Cystic Fibrosis / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000494:pharmacology*; D004721:Endoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005408:Flagellin / Q000494:pharmacology; D006801:Humans; D007249:Inflammation; D016209:Interleukin-8 / Q000378:metabolism; D018613:Microscopy, Confocal; D009154:Mutation / Q000235:genetics; D016328:NF-kappa B / Q000378:metabolism; D011552:Pseudomonas Infections / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D011550:Pseudomonas aeruginosa / Q000472:pathogenicity; D020545:Respiratory Mucosa / Q000187:drug effects* / Q000378:metabolism