title: MMP-2 activation by Actinobacillus actinomycetemcomitans supernatant in human PDL cells was corresponded with reduction of TIMP-2.
abstract: OBJECTIVE
  Matrix metalloproteinase 2 (MMP-2) has been implicated to play a role in pathogenesis of periodontal disease. We recently reported that Porphyromonas gingivalis supernatant could activate MMP-2 in human periodontal ligament (HPDL) cells. In this study, activation of MMP-2 by Actinobacillus actinomycetemcomitans supernatant and the mechanism was investigated.
  
  
  METHODS
  HPDL cells were treated with either A. actinomycetemcomitans or P. gingivalis supernatant for 48 h. To verify the mechanism, pretreated inhibitors were used. Gelatin zymography, RT-PCR and Western blot analysis were used to detect the activation of MMP-2, expression of MT1-MMP and TIMP-2 mRNA and the proteins, respectively.
  
  
  RESULTS
  The supernatant from A. actinomycetemcomitans could activate MMP-2 in HPDL cells similar to that from P. gingivalis but by a different mechanism. Activation by A. actinomycetemcomitans supernatant was correlated with a reduction of TIMP-2 secretion without any alteration of MT1-MMP, while activation by P. gingivalis increased MT1-MMP but no change of TIMP-2 was found.
  
  
  CONCLUSIONS
  The supernatant from A. actinomycetemcomitans and P. gingivalis could induce the activation of MMP-2 possibly through the imbalance of MT1-MMP and TIMP-2 in HPDL cells but by different mechanisms. The imbalance of MT1-MMP and TIMP-2 may be another factor that is involved in the severity of periodontal disease.
authors.affiliation: Department of Anatomy, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.
authors.forename: S
authors.initials: S
authors.lastname: Tiranathanagul
authors.forename: K
authors.initials: K
authors.lastname: Pattamapun
authors.forename: T
authors.initials: T
authors.lastname: Yongchaitrakul
authors.forename: P
authors.initials: P
authors.lastname: Pavasant
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000378:metabolism*; D000704:Analysis of Variance; D015153:Blotting, Western; D002460:Cell Line; D004789:Enzyme Activation; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D010513:Periodontal Ligament / Q000201:enzymology; D016133:Polymerase Chain Reaction; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism*
chemical_list: D019716:Tissue Inhibitor of Metalloproteinase-2; D020778:Matrix Metalloproteinase 2