title: Fusobacterium nucleatum biofilm induces epithelial migration in an organotypic model of dento-gingival junction.
abstract: BACKGROUND
  Effects of Fusobacterium nucleatum (F. nucleatum) biofilm on epithelial cell proliferation, apoptotic cell death, and basement membrane constituent collagen IV production were examined in an organotypic dento-epithelial (OD-E) model.
  
  
  METHODS
  The OD-E model was constructed by seeding keratinocytes on fibroblast-containing collagen gels and by placing tooth pieces on top. A 3-day-old biofilm either a laboratory strain (American Type Culture Collection [ATCC] 25586) or a clinical strain (Anaerobe Helsinki Negative [AHN] 9508) of F. nucleatum was placed on the top of the model. The coculture was incubated ≤24 hours. The expression and localization of Ki-67, caspase-3, and collagen IV were examined by immunohistochemistry.
  
  
  RESULTS
  Hematoxylin and eosin staining showed epithelial migration and lateral sprouting into the connective tissue matrix in F. nucleatum OD-E cocultures. The proliferation pattern of the in vitro dento-epithelial junction was changed. In controls without bacterial challenge, the Ki-67 expression was abundant in the cells attached to the tooth, whereas in F. nucleatum biofilm-treated cultures, the Ki-67-expressing cells were more often in the connective tissue-facing side of the epithelium. An apoptotic marker caspase-3 was expressed in controls and in F. nucleatum laboratory strain ATCC cocultures throughout the epithelium, in contrast to cultures treated with F. nucleatum clinical strain AHN, in which caspase-3 was absent. Collagen IV stainings were negative in both controls and F. nucleatum cocultures.
  
  
  CONCLUSIONS
  F. nucleatum biofilm coculture with OD-E model causes lateral sprouting of the epithelium with an altered epithelial proliferation pattern, resembling the histologic changes seen in vivo in the early pathogenesis of periodontal disease.
authors.affiliation: Department of Periodontology, Institute of Dentistry, University of Turku, Turku, Finland. marja.pollanen@utu.fi
authors.forename: Marja T
authors.initials: MT
authors.lastname: Pöllänen
authors.forename: Ulvi K
authors.initials: UK
authors.lastname: Gursoy
authors.forename: Eija
authors.initials: E
authors.lastname: Könönen
authors.forename: Veli-Jukka
authors.initials: VJ
authors.lastname: Uitto
mesh_terms: D017209:Apoptosis; D001485:Basement Membrane / Q000378:metabolism; D018441:Biofilms; D053148:Caspase 3 / Q000096:biosynthesis; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D024141:Collagen Type IV / Q000096:biosynthesis; D003238:Connective Tissue / Q000033:anatomy & histology; D004846:Epithelial Attachment / Q000033:anatomy & histology* / Q000166:cytology / Q000382:microbiology*; D005347:Fibroblasts; D016967:Fusobacterium nucleatum / Q000502:physiology*; D005881:Gingiva / Q000033:anatomy & histology / Q000382:microbiology*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000502:physiology*; D019394:Ki-67 Antigen / Q000096:biosynthesis; D008954:Models, Biological; D009924:Organ Culture Techniques
chemical_list: D024141:Collagen Type IV; D019394:Ki-67 Antigen; D053148:Caspase 3