Abstract
Tissue reactions to bacteria lead to proinflammatory reactions involving matrix metalloproteinases (MMPs). Synthetic protease inhibitors may offer new possibilities to regulate bacterial proteases. We investigated proteolytic activities of certain periodontal bacteria, their effects on the latent proMMP-9, and the effects of synthetic MMP inhibitors and a serine protease inhibitor Pefabloc. The strains studied were Porphyromonas gingivalis, Prevotella intermedia, Peptostreptoccus micros, Prevotella nigrescens, Fusobacterium nucleatum, and 5 Aggregatibacter actinomycetemcomitans serotypes. Their gelatinolytic activities and the effects of certain synthetic MMP inhibitors and Pefabloc were analyzed by zymography. Bacterial effects on proMMP-9 conversion were investigated by Western immunoblot. All investigated periodontal bacteria produced gelatinolytic cell-bound and extracellular proteinases which could fragment latent proMMP-9, suggesting co-operative processing cascades in oral tissue remodeling. A. actinomycetemcomitans produced the weakest gelatinolytic activity. Synthetic proteinase inhibitors exhibited slight but clear reductive effects on the bacterial proteolytic activities. We conclude that targeted anti-proteolytic treatment modalities against bacterial-host proteolytic cascades can be developed.
Highlights
Tissue reaction to bacteria leads to an excessive host inflammatory response
The cells were harvested by centrifugation at 14,000 rpm for 20 min at 4°C, washed 3 times with neutral phosphate buffer saline (PBS) and rediluted in PBS so that the final concentrations of the cells were twice higher of the original concentration for P. gingivalis and 4 times higher for the other species
The present results showed a highly complex pattern of proteinase activities of the different bacterial strains investigated which may, at least in part, indicate differences in their virulence
Summary
Tissue reaction to bacteria leads to an excessive host inflammatory response. Inflammatory cells secrete matrixdegrading proteinases, including matrix metalloproteinases (MMPs). MMPs can degrade and modify almost all matrix and basement membrane proteins in growth and in normal tissue turnover [1,2]. Elevated MMP levels, especially neutrophil gelatinase B (MMP-9) together with lesser extent neutrophil collagenase-2 (MMP-8) are considered as potential markers for tissue destruction in inflammation [1,2,3,4,5]. The severity and course of tissue destruction in oral infections can be monitored by assessing oral fluid MMP-8 levels [6, 7]. MMP-9 and -8 have been shown to exert anti-inflammatory or defensive characteristics [8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
