title: Porphyromonas gingivalis peptidylarginine deiminase, a key contributor in the pathogenesis of experimental periodontal disease and experimental arthritis.
abstract: OBJECTIVE
  To investigate the suggested role of Porphyromonas gingivalis peptidylarginine deiminase (PAD) in the relationship between the aetiology of periodontal disease and experimentally induced arthritis and the possible association between these two conditions.
  
  
  METHODS
  A genetically modified PAD-deficient strain of P. gingivalis W50 was produced. The effect of this strain, compared to the wild type, in an established murine model for experimental periodontitis and experimental arthritis was assessed. Experimental periodontitis was induced following oral inoculation with the PAD-deficient and wild type strains of P. gingivalis. Experimental arthritis was induced via the collagen antibody induction process and was monitored by assessment of paw swelling and micro-CT analysis of the radio-carpal joints. Experimental periodontitis was monitored by micro CT scans of the mandible and histological assessment of the periodontal tissues around the mandibular molars. Serum levels of anti-citrullinated protein antibodies (ACPA) and P. gingivalis were assessed by ELISA.
  
  
  RESULTS
  The development of experimental periodontitis was significantly reduced in the presence of the PAD-deficient P. gingivalis strain. When experimental arthritis was induced in the presence of the PAD-deficient strain there was less paw swelling, less erosive bone damage to the joints and reduced serum ACPA levels when compared to the wild type P. gingivalis inoculated group.
  
  
  CONCLUSIONS
  This study has demonstrated that a PAD-deficient strain of P. gingivalis was associated with significantly reduced periodontal inflammation. In addition the extent of experimental arthritis was significantly reduced in animals exposed to prior induction of periodontal disease through oral inoculation of the PAD-deficient strain versus the wild type. This adds further evidence to the potential role for P. gingivalis and its PAD in the pathogenesis of periodontitis and exacerbation of arthritis. Further studies are now needed to elucidate the mechanisms which drive these processes.
authors: Colgate Australian Clinical Dental Research, School of Dentistry, University of Adelaide, Adelaide, South Australia, Australia.
authors: Neville
authors: N
authors: Gully
authors: Colgate Australian Clinical Dental Research, School of Dentistry, University of Adelaide, Adelaide, South Australia, Australia.
authors: Richard
authors: R
authors: Bright
authors: Colgate Australian Clinical Dental Research, School of Dentistry, University of Adelaide, Adelaide, South Australia, Australia.
authors: Victor
authors: V
authors: Marino
authors: Colgate Australian Clinical Dental Research, School of Dentistry, University of Adelaide, Adelaide, South Australia, Australia.
authors: Ceilidh
authors: C
authors: Marchant
authors: Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia.
authors: Melissa
authors: M
authors: Cantley
authors: Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia.
authors: David
authors: D
authors: Haynes
authors: Oral Health Collaborative Research Centre, Melbourne Dental School, The University of Melbourne, Melbourne, Victoria, Australia.
authors: Catherine
authors: C
authors: Butler
authors: Oral Health Collaborative Research Centre, Melbourne Dental School, The University of Melbourne, Melbourne, Victoria, Australia.
authors: Stuart
authors: S
authors: Dashper
authors: Oral Health Collaborative Research Centre, Melbourne Dental School, The University of Melbourne, Melbourne, Victoria, Australia.
authors: Eric
authors: E
authors: Reynolds
authors: Colgate Australian Clinical Dental Research, School of Dentistry, University of Adelaide, Adelaide, South Australia, Australia.
authors: Mark
authors: M
authors: Bartold
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000150:complications* / Q000000981:diagnostic imaging; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D006867:Hydrolases / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010518:Periodontitis / Q000150:complications / Q000000981:diagnostic imaging / Q000209:etiology*; D016966:Porphyromonas gingivalis / Q000235:genetics; D000076342:Protein-Arginine Deiminases; D011859:Radiography
chemical_list: D001426:Bacterial Proteins; D006867:Hydrolases; D000076342:Protein-Arginine Deiminases