title: Hepatocytes produce tumor necrosis factor-α and interleukin-6 in response to Porphyromonas gingivalis.
abstract: OBJECTIVE
  The liver plays a major role in clearing systemic bacterial infections. In addition, inflammatory cytokines produced in the liver play a critical role in systemic cytokine levels. The aim of this study was to investigate the production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) by hepatocytes in response to periodontal pathogens.
  
  
  METHODS
  The mouse hepatic carcinoma cell line Hepa-1.6 and the mouse macrophage-like cell line RAW 264 were co-cultured in Transwell insert plates. Cells were stimulated with bacterial extracts prepared from Porphyromonas gingivalis and the induction of TNF-α and IL-6 was measured using real-time PCR and ELISA.
  
  
  RESULTS
  After stimulation with bacteria, the induction of TNF-α and IL-6 was observed in RAW 264 cells and Hepa-1.6 cells. Significant reduction of TNF-α mRNA expression in Hepa-1.6 cells was observed after treatment with antibody to TNF-α.
  
  
  CONCLUSIONS
  The results obtained in the present study show that P. gingivalis extract induces TNF-α and IL-6 in an in vitro liver model and that macrophage-derived TNF-α mediates the induction of TNF-α in hepatocytes.
authors: Nihon University Graduate School of Dentistry, Tokyo, Japan Department of Periodontology, Nihon University School of Dentistry, Tokyo, Japan.
authors: M
authors: M
authors: Takano
authors: N
authors: N
authors: Sugano
authors: S
authors: S
authors: Mochizuki
authors: R N
authors: RN
authors: Koshi
authors: T S
authors: TS
authors: Narukawa
authors: Y
authors: Y
authors: Sawamoto
authors: K
authors: K
authors: Ito
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D001431:Bacteriological Techniques; D002460:Cell Line; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D004797:Enzyme-Linked Immunosorbent Assay; D022781:Hepatocytes / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology; D015850:Interleukin-6 / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D051379:Mice; D016966:Porphyromonas gingivalis / Q000276:immunology*; D060888:Real-Time Polymerase Chain Reaction; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
chemical_list: D000906:Antibodies; D007074:Immunoglobulin G; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha