title: EGR-1 and DUSP-1 are important negative regulators of pro-allergic responses in airway epithelium.
abstract: BACKGROUND
  Primary nasal epithelium of house dust mite allergic individuals is in a permanently activated inflammatory transcriptional state.
  
  
  OBJECTIVE
  To investigate whether a deregulated expression of EGR-1 and/or DUSP-1, two potential negative regulators of pro-inflammatory responses, could contribute to the activation of the inflammatory state.
  
  
  METHODS
  We silenced the expression of EGR-1 or DUSP-1 in the airway epithelial cell line NCI-H292. The cell lines were stimulated in a 24-h time course with the house dust mite allergen or poly(I:C). RNA expression profiles of cytokines were established using q-PCR and protein levels were determined in supernatants with ELISA.
  
  
  RESULTS
  The shRNA-mediated gene silencing reduced expression levels of EGR-1 by 92% (p<0.0001) and of DUSP-1 by 76% (p<0.0001). Both mutant cells lines showed an increased and prolonged response to the HDM allergen. The mRNA induction of IL-6 was 4.6 fold (p=0.02) and 2.4 fold higher (p=0.01) in the EGR-1 and DUSP-1 knock-down, respectively when compared to the induced levels in the control cell line. For IL-8, the induction levels were 4.6 fold (p=0.01) and 13.0 (p=0.001) fold higher. The outcome was largely similar, yet not identical at the secreted protein levels. Furthermore, steroids were able to suppress the poly(I:C) induced cytokine levels by 70-95%.
  
  
  CONCLUSIONS
  Deregulation of EGR-1 and/or DUSP-1 in nasal epithelium could be responsible for the prolonged activated transcriptional state observed in vivo in allergic disease. This could have clinical consequences as cytokine levels after the steroid treatment in EGR-1 or DUSP-1 knock-down remained higher than in the control cell line.
authors: Department of Otorhinolaryngology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands. Electronic address: k.golebski@amc.uva.nl.
authors: Korneliusz
authors: K
authors: Golebski
authors: Department of Otorhinolaryngology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands.
authors: Danielle
authors: D
authors: van Egmond
authors: Department of Otorhinolaryngology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands.
authors: Esther J
authors: EJ
authors: de Groot
authors: Department of Otorhinolaryngology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands.
authors: Kristina I L
authors: KI
authors: Roschmann
authors: Department of Otorhinolaryngology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands.
authors: Wytske J
authors: WJ
authors: Fokkens
authors: Department of Otorhinolaryngology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands.
authors: Cornelis M
authors: CM
authors: van Drunen
mesh_terms: D000485:Allergens / Q000276:immunology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D039741:Antigens, Dermatophagoides / Q000276:immunology*; D002460:Cell Line; D003907:Dexamethasone / Q000494:pharmacology; D054638:Dual Specificity Phosphatase 1 / Q000096:biosynthesis / Q000235:genetics*; D051766:Early Growth Response Protein 1 / Q000096:biosynthesis / Q000235:genetics*; D004847:Epithelial Cells / Q000166:cytology / Q000276:immunology; D020869:Gene Expression Profiling; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology; D007249:Inflammation / Q000276:immunology; D015850:Interleukin-6 / Q000096:biosynthesis; D016209:Interleukin-8 / Q000096:biosynthesis; D011070:Poly I-C / Q000276:immunology; D039981:Pyroglyphidae / Q000276:immunology*; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering; D020545:Respiratory Mucosa / Q000166:cytology / Q000276:immunology*
chemical_list: D000485:Allergens; D000893:Anti-Inflammatory Agents; D039741:Antigens, Dermatophagoides; C508606:CXCL8 protein, human; C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1; C508600:IL6 protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D003907:Dexamethasone; C517019:DUSP1 protein, human; D054638:Dual Specificity Phosphatase 1; D011070:Poly I-C
keywords: Allergy; House dust mite; Poly(I:C); Transcription factors; Virus