IL-1beta induces IL-8 in bronchial cells via NF-kappaB and NF-IL6 transcription factors and can be suppressed by glucocorticoids.
IL-1beta may contribute to airway inflammation by inducing pro-inflammatory cytokines and chemokines from bronchial epithelial cells. In the current study, we investigated the cis-acting sites within the IL-8 promoter, and signalling pathways important in IL-8 production from BEAS2B cells following IL-1beta stimulation. IL-1beta treatment (0.1-10 ng/mL) upregulated IL-8 protein production in a dose dependent manner and IL-8 mRNA in a time dependent manner. IL-1beta induced upregulation of IL-8 promoter-reporter constructs, indicating that the mechanism of upregulation was pre-transcriptional. Using IL-8 promoter constructs with mutated cis-acting sites, it was found that both the NF-kappaB and NF-IL6 sites together were required for IL-8 promoter induction following IL-1beta treatment. Using chemical inhibitors or dominant negative mutants, we found that IL-8 promoter activity required IkappaB kinase beta, IkappaB, but not the MAP kinases p38 or c-Jun N-terminal kinase 2. Fluticasone propionate was able to suppress IL-1beta induced IL-8 protein and promoter activation, using both a -1481 bp fragment and a -133 bp fragment, indicating that the glucocorticoid response element found at -330 bp was not required for fluticasone mediated suppression of IL-8 promoter activation.
Edwards
Michael R
MR
Department of Respiratory Medicine, St Mary's Hospital, National Heart Lung Institute, Imperial College London, Norfolk Place W2 1PG, London, UK. michael.edwards@ic.ac.uk
Mukaida
Naofumi
N
Johnson
Malcolm
M
Johnston
Sebastian L
SL
D000730:Androstadienes / Q000627:therapeutic use; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy / Q000473:pathology; D001980:Bronchi / Q000166:cytology / Q000187:drug effects*; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000378:metabolism; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects; D000068298:Fluticasone; D006801:Humans; D007375:Interleukin-1 / Q000008:administration & dosage / Q000494:pharmacology*; D016209:Interleukin-8 / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014157:Transcription Factors; D015854:Up-Regulation
D000730:Androstadienes; D000893:Anti-Inflammatory Agents; D022782:CCAAT-Enhancer-Binding Protein-beta; D007375:Interleukin-1; D016209:Interleukin-8; D016328:NF-kappa B; D012333:RNA, Messenger; D014157:Transcription Factors; D000068298:Fluticasone