ABCMdb

PMID: 11404248

Weber AJ, Soong G, Bryan R, Saba S, Prince A
Activation of NF-kappaB in airway epithelial cells is dependent on CFTR trafficking and Cl- channel function.
Am J Physiol Lung Cell Mol Physiol. 2001 Jul;281(1):L71-8., [PubMed]

Sentences

No. Mutations Sentence Comment

11 ABCC7 p.Gly551Asp Mutant ⌬F508 CFTR is mistrafficked, accumulates in the endoplasmic reticulum (ER), and may cause "cell stress" and activation of nuclear factor (NF)-␬B. G551D mutants also lack Cl-channel function, but CFTR is trafficked normally. Login to comment 13 ABCC7 p.Gly551Asp In transfected Chinese hamster ovary cells, the mistrafficked ⌬F508 allele caused a sevenfold activation of NF-␬B compared with wild-type CFTR or the G551D mutant (P Ͻ 0.001). Login to comment 41 ABCC7 p.Trp1282* Comparison of the endogenous activation of NF-␬B in IB3 cells (W1282X/⌬F508), a trafficking mutant similar to the homozygous ⌬F508 mutation, with that in corrected C-38 cells, which express a functional but truncated form of CFTR, was consistent with this hypothesis. Login to comment 47 ABCC7 p.Gly551Asp The G551D CFTR mutant, in which a conserved glycine in the ATP binding cassette is mutated, lacks Cl-channel function, but the protein is properly folded and trafficked (12). Login to comment 48 ABCC7 p.Gly551Asp Patients with the G551D mutation have a clinical disease that is indistinguishable from that caused by the more common ⌬F508 mutation (10). Login to comment 56 ABCC7 p.Trp1282* IB3 cells (⌬F508/W1282X), a human bronchial epithelial cell line, and C-38 cells, "corrected" cells with normal physiology that express an episomal truncated form of CFTR (33), were obtained from P. Zeitlin (Johns Hopkins University, Baltimore, MD) and grown in LHC-8 medium (Biofluids, Rockville, MD) plus 10% FCS. Login to comment 60 ABCC7 p.Gly551Asp Stably transfected Chinese hamster ovary (CHO)-K1 cells that express ⌬F508 CFTR or G551D CFTR were obtained from J. Riordan (Mayo Clinic Scottsdale, Scottsdale, AZ) and grown in ␣MEM plus 200 ␮M methotrexate plus 8% FCS. Login to comment 61 ABCC7 p.Gly551Asp CHO-K1 cells were obtained from the American Type Culture Collection (ATCC) and lipofected with pCep plasmid constructs expressing either wild-type CFTR, G551D CFTR, ⌬F508 CFTR, or the vector alone, provided by M. Drumm (Case Western Reserve University, Cleveland OH). Login to comment 107 ABCC7 p.Gly551Asp Activation of NF-␬B in CHO Cells Expressing Wild-Type and Mutant CFTR CHO cells that were transiently transfected with the pCep empty vector or pCep vector expressing wild-type CFTR had low levels of basal NF-␬B activation as did the cells transfected with the plasmid expressing the mutant G551D CFTR (Fig. 3A). Login to comment 109 ABCC7 p.Gly551Asp Experiments done with stably transfected CHO cells yielded similar results (Fig. 3C); expression of ⌬F508 CFTR was associated with a sevenfold increase in reporter activation compared with that in the CHO cells expressing the G551D mutation (P Ͻ 0.001) or CHO cells transfected with the reporter construct alone (P Ͻ 0.001). Login to comment 111 ABCC7 p.Gly551Asp In the CHO cells, expression of the ⌬F508 CFTR mutation was sufficient to activate NF-␬B, whereas the presence of comparable amounts of the mutant G551D CFTR was not. Login to comment 132 ABCC7 p.Gly551Asp A: relative activation of an NF-␬B-luciferase reporter construct in CHO cells without CFTR (-) or transiently transfected with the pCep vector; wild-type (wt) CFTR, G551D CFTR, or ⌬F508 CFTR cloned in pCep (n ϭ 12 experiments). Login to comment 134 ABCC7 p.Gly551Asp B: immunodetection of CFTR in the transiently transfected CHO cells: Lane A, control CHO cells; lane B, pCep-wild-type CFTR; lane C, pCep- G551D CFTR; lane D, pCep-⌬F508 CFTR. Login to comment 138 ABCC7 p.Gly551Asp Lane A, without CFTR (control); lane B, G551D CFTR; lane C, ⌬F508 CFTR. Login to comment 154 ABCC7 p.Trp1282* In previous studies, IB3 cells, which express the W1282X/⌬F508 mutation associated with mistrafficked CFTR that accumulates in the ER, were found to have significant amounts of the p65 component of NF-␬B in nuclei under basal conditions in which there was no nuclear NF-␬B in the corrected C-38 cells (8). Login to comment 179 ABCC7 p.Gly551Asp The G551D CFTR, which does not function appropriately as a Cl-channel but is trafficked normally to the apical surface of the respiratory epithelial cell (10), did not stimulate NF-␬B. Login to comment 181 ABCC7 p.Gly551Asp Although both the G551D and ⌬F508 CFTR mutations are associated with clinical disease and lack of Cl-secretion in response to cAMP (10), the major difference between these mutants is the mistrafficking and accumulation of ⌬F508 CFTR within the ER. Login to comment 184 ABCC7 p.Trp1282* The homozygous ⌬F508 or the compound ⌬F508/W1282X mutation could activate NF-␬B by two independent mechanisms: cell stress associated with mistrafficking or effects directly due to lack of CFTR Cl-channel activity. Login to comment