title: The impact of virulence factors of Porphyromonas gingivalis on wound healing in vitro.
abstract: BACKGROUND
  Porphyromonas gingivalis inhibits oral epithelial wound healing in vitro more strongly than other oral bacteria, but it is unknown why P. gingivalis is such a potent inhibitor of wound healing.
  
  
  OBJECTIVE
  Therefore, the aim of this study was to investigate the influence of major virulence factors of P. gingivalis on wound healing in an in vitro wound-healing model. The influence of the capsular polysaccharide, the Arg- and Lys- gingipains, the major fimbriae and lipopolysaccharide (LPS) was investigated.
  
  
  METHODS
  A standardized scratch was made in a confluent layer of human oral epithelial cells HO-1-N-1. The epithelial cells were then challenged with different concentrations of several P. gingivalis wild-type strains and knockout mutants. Closure of the scratch was determined after 17 h and compared to control conditions without bacteria.
  
  
  RESULTS
  The P. gingivalis strains ATCC 33277, W83, and W50 significantly inhibited wound healing. The presence of a capsular polysaccharide lowered significantly the inhibition of epithelial cell migration, while gingipain activity significantly increased the inhibition of cell migration. LPS and the major fimbriae did not influence epithelial cell migration. None of the tested P. gingivalis strains completely prevented the inhibition of cell migration, suggesting that other characteristics of P. gingivalis also play a role in the inhibition of wound healing, and that further research is needed.
  
  
  CONCLUSIONS
  The capsular polysaccharide and the Arg- and Lys- gingipains of P. gingivalis influenced the capacity of P. gingivalis to hinder wound healing, while LPS and the major fimbriae had no effect.
authors.affiliation: Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands; a.laheij@acta.nl.
authors.forename: Alexa M G A
authors.initials: AM
authors.lastname: Laheij
authors.affiliation: Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands.
authors.forename: Cor
authors.initials: C
authors.lastname: van Loveren
authors.affiliation: Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Deng
authors.affiliation: Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands.
authors.forename: Johannes J
authors.initials: JJ
authors.lastname: de Soet
keywords: LPS; P. gingivalis; capsular polysaccharide; cell migration essay; gingipains; oral epithelial cells; re-epithelialization