title: Nicotine up-regulates IL-8 expression in human gingival epithelial cells following stimulation with IL-1β or P. gingivalis lipopolysaccharide via nicotinic acetylcholine receptor signalling.
abstract: OBJECTIVE
  Cigarette smoking is an important risk factor for periodontal disease. The aim of this study is to evaluate the effect of nicotine, a major component of cigarette smoke, on interleukin-8 (IL-8) production and cellular signalling via nicotinic acetylcholine receptors (nAChRs) in human gingival epithelial cells (HGECs).
  
  
  METHODS
  Messenger RNA (mRNA) expression of nAChR subunits in three different HGEC lines (epi 4, Tfx and E6E7) was assessed using reverse transcription-polymerase chain reaction (RT-PCR). HGECs were stimulated by 1×10(-3)M nicotine in the presence or absence of IL-1β or Porphyromonas gingivalis lipopolysaccharide (LPS). IL-8 production was then examined using real-time PCR and enzyme-linked immunosorbent assay. Nicotine-mediated signalling in the epi 4 cell line was also evaluated by Western blotting.
  
  
  RESULTS
  HGECs expressed several nAChR subunits. Nicotine increased the secretion of IL-8 from HGECs that were cultured in the presence of IL-1β or P. gingivalis LPS and also induced the phosphorylation of extracellular signal-regulated kinase (ERK) in epi 4. Pretreatment with non-selective nAChR antagonist or intracellular calcium chelator reduced the nicotine-induced phosphorylation of ERK. Furthermore, nicotine-induced IL-8 secretion was decreased by pretreatment with non-selective nAChR antagonist, ERK1/2 inhibitor or intracellular calcium chelator.
  
  
  CONCLUSIONS
  These findings indicate that nicotine increases IL-8 production in gingival epithelial cells via ERK phosphorylation following Ca(2+) signalling after nAChR activation.
authors: Department of Periodontology, Division of Oral Biology and Disease Control, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors: Yoichiro
authors: Y
authors: Kashiwagi
authors: Manabu
authors: M
authors: Yanagita
authors: Yuko
authors: Y
authors: Kojima
authors: Yoshio
authors: Y
authors: Shimabukuro
authors: Shinya
authors: S
authors: Murakami
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D002460:Cell Line; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005881:Gingiva / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology*; D016209:Interleukin-8 / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009538:Nicotine / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D016966:Porphyromonas gingivalis / Q000276:immunology*; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D011978:Receptors, Nicotinic / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D053583:Interleukin-1beta; D016209:Interleukin-8; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D011978:Receptors, Nicotinic; D009538:Nicotine; D048049:Extracellular Signal-Regulated MAP Kinases; D020928:Mitogen-Activated Protein Kinases