title: Role of IKK and ERK pathways in intrinsic inflammation of cystic fibrosis airways.
abstract: In cystic fibrosis (CF) patients, pulmonary inflammation is a major cause of morbidity and mortality and may precede bacterial colonization. The aim of the present study was to investigate the molecular mechanisms underlying intrinsic inflammation in cystic fibrosis airways. Using different cystic fibrosis cell models, we first demonstrated that, beside a high constitutive nuclear factor of kappaB (NF-kappaB) activity, CF cells showed a higher activator protein-1 (AP-1) activity as compared to their respective control cells. Gene expression profiles, confirmed by RT-PCR and ELISA, showed over-expression of numerous NF-kappaB and AP-1-dependent pro-inflammatory genes in CF cells in comparison with control cells. Activation of NF-kappaB was correlated with higher inhibitor of kappaB kinase (IKK) activity. In addition, Bio-plex phosphoprotein assays revealed higher extracellular signal-regulated kinase (ERK) phosphorylation in CFT-2 cells. Inhibition of this kinase strongly decreased expression of pro-inflammatory genes coding for growth-regulated proteins (Gro-alpha, Gro-beta and Gro-gamma) and interleukins (IL-1beta, IL-6 and IL-8). Moreover, inhibition of secreted interleukin-1beta (IL-1beta) and basic fibroblast growth factor (bFGF) with neutralizing antibodies reduced pro-inflammatory gene expression. Our data thus demonstrated for the first time that the absence of functional cystic fibrosis transmembrane conductance regulator (CFTR) at the plasma membrane leads to an intrinsic AP-1, in addition to NF-kappaB, activity and consequently to a pro-inflammatory state sustained through autocrine factors such as IL-1beta and bFGF.
authors.affiliation: Units of Medical Chemistry and Human Genetics (GIGA-R), University of Liège, CHU Sart-Tilman B35, B-4000 Liège, Belgium.
authors.forename: Catherine
authors.initials: C
authors.lastname: Verhaeghe
authors.forename: Caroline
authors.initials: C
authors.lastname: Remouchamps
authors.forename: Benoît
authors.initials: B
authors.lastname: Hennuy
authors.forename: Alain
authors.initials: A
authors.lastname: Vanderplasschen
authors.forename: Alain
authors.initials: A
authors.lastname: Chariot
authors.forename: Sebastien P
authors.initials: SP
authors.lastname: Tabruyn
authors.forename: Cecile
authors.initials: C
authors.lastname: Oury
authors.forename: Vincent
authors.initials: V
authors.lastname: Bours
mesh_terms: D002461:Cell Line, Transformed; D054360:Chemokine CXCL1; D054426:Chemokine CXCL2; D019743:Chemokines, CXC / Q000378:metabolism; D003550:Cystic Fibrosis / Q000378:metabolism* / Q000473:pathology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D015870:Gene Expression; D017930:Genes, Reporter; D006367:HeLa Cells; D006720:Homozygote; D006801:Humans; D051550:I-kappa B Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007249:Inflammation / Q000473:pathology; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation; D016328:NF-kappa B / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014132:Trachea / Q000166:cytology / Q000196:embryology; D018808:Transcription Factor AP-1 / Q000378:metabolism
chemical_list: C475829:CXCL1 protein, human; C499706:CXCL2 protein, human; C499707:CXCL3 protein, human; D054360:Chemokine CXCL1; D054426:Chemokine CXCL2; D019743:Chemokines, CXC; D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; D016328:NF-kappa B; D018808:Transcription Factor AP-1; D016222:Fibroblast Growth Factor 2; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D008156:Luciferases; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; D048049:Extracellular Signal-Regulated MAP Kinases