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 Porphyromonos 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 MTI-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 MTI-MMP, while activation by P. gingivalis increased MTI-MMP but no change of TIMP-2 was found. CONCLUSION: The supernatant from A. actinomycetemcomitans and P. gingivalis could induce the activation of MMP-2 possibly through the imbalance of MTI-MMP and TIMP-2 in HPDL cells but by different mechanisms. The imbalance of MTI-MMP and TIMP-2 may be another factor that is involved in the severity of periodontal disease.