Activation of plasminogen by Streptococcus mutans

Jones, Micheala N.; Holt, Robert G.

doi:10.1016/j.bbrc.2004.07.077

Cited by 12 publications

(14 citation statements)

References 20 publications

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“…Our results showed that all the tested strains produced streptokinase, which thus most likely was responsible for the plasminogen activation in the fibrinolysis assay. This finding is in agreement with those of Jones & Holt (2004), who however interpreted their results with S. mutans M51 to be the effect of a plasminogen activator localized on the cell surface, although no evidence was provided for this being a genuine proteolytic plasminogen activator rather than a complex-former like streptokinase. Our present results demonstrate, we believe for the first time, the production of streptokinase by streptococci of oral origin.…”

Section: Discussionsupporting

confidence: 89%

“…In addition to the overtly pathogenic bacterial species, plasminogen is also bound by bacteria belonging to the normal flora of the mouth, such as Streptococcus mutans (Jones & Holt, 2004), Peptostreptococcus micros (Grenier & Bouclin, 2006) and Fusobacterium nucleatum (Darenfed et al, 1999;Coleman & Benach, 1999;Lottenberg et al, 1994). The bacteria colonizing the teeth are flooded by gingival crevicular fluid, a tissue transudate containing plasma proteins, as well as proteins produced and released in the local gingival tissue.…”

Section: Introductionmentioning

confidence: 99%

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Plasminogen binding by oral streptococci from dental plaque and inflammatory lesions

2008

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Plasminogen binding by bacteria is a virulence factor important for the entry and dissemination of bacteria in the body. A wide variety of bacteria bind plasminogen, including both organisms causing disease and components of the normal oral flora. The purpose of this study was to examine the characteristics of plasminogen binding by six clinical isolates of oral streptococci from both dental plaque and inflammatory lesions. All the strains bound plasminogen with approximately the same affinity, and binding was specific and lysine-dependent as evidenced by its inhibition by e-aminocaproic acid. All of the test strains were capable of activating bound plasminogen to plasmin without the addition of a plasminogen activator, and subsequent analysis revealed the presence of streptokinase in all strains. However, the streptococci exhibited fibrinolytic activity only in the presence of plasminogen and this could be inhibited by the addition of e-aminocaproic acid. SDS-PAGE and 2D gel electrophoresis coupled with plasminogen ligand blotting showed that only a subset of the total proteins (2-15) were involved in the binding of plasminogen. Partial identification of the binding proteins revealed that four glycolytic enzymes, enolase, phosphoglycerate kinase, glyceraldehyde-3-phosphate dehydrogenase and phosphoglycerate mutase, were predominant in binding plasminogen. The binding of plasminogen by bacteria from pus did not differ from that of the strains from supragingival plaque. The findings illustrate how apparently innocuous commensal bacteria are capable of utilizing a mechanism that is generally regarded as being of importance to pathogenicity and suggest an additional role of plasminogen binding.

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Section: Discussionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Plasminogen binding by oral streptococci from dental plaque and inflammatory lesions

2008

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“…Here, we report that u-PA contained within infected vegetations is able to convert exogenous plasminogen into plasmin. Unlike bacterial strains that possess plasminogen-activating systems, such as Streptococcus mutans or Staphylococcus aureus (32,33), the strain we used is devoid of any plasminogen activators. In our model, plasminogen activators are thus conveyed by leukocytes attracted to the site of the vegetation.…”

Section: Discussionmentioning

confidence: 99%

Predominant Role of Host Proteases in Myocardial Damage Associated with Infectious Endocarditis Induced by Enterococcus faecalis in a Rat Model

et al. 2013

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f Infective endocarditis (IE) remains a life-threatening infectious disease with high morbidity and mortality. The objectives of the present study are to assess the host proteolytic activities of the vegetations and their cytotoxic potential in a rat model of experimental IE. Rats were infected with a strain of Enterococcus faecalis of particularly low virulence and weak protease expression. We tested the presence of proteases released by infiltrated leukocytes (matrix metalloproteinases and elastase) or produced in situ within the septic vegetation, such as those linked to the fibrinolytic system (plasmin and plasminogen activators). We also assessed the tissue damage induced by the infective thrombus in vitro and ex vivo. The model of IE was characterized by larger and more extensive vegetations in infected than in nonseptic rats and by an intense neutrophil infiltrate interfacing with the injured underlying tissue. Neutrophil extracellular DNA was shown to trap bacteria and to produce increased levels of cell-free DNA in plasma. Matrix metalloproteinase-9, elastase, and plasminogen activators were increased in septic versus nonseptic vegetations (as shown by zymography and immunohistology). Finally, proteolysis of the extracellular matrix and apoptosis were shown to be associated with host proteases. Bacteria exhibited no detectable proteolytic activity or direct cytotoxic effects. Bacterial membranes/dead bacteria were sufficient to induce leukocyte recruitment and activation that could promote vegetation formation and growth. Our results suggest that, despite the lack of bacterial proteases, the continuous attractant signals coming from bacterial colonies may lead to a chronic and deleterious aggression toward myocardial/valvular tissues by host proteases.

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“…Therefore, activation of plasmin(ogen) by NAPlr is a more likely mode of action in PSGN pathogenesis than activation of the complement system by this bacterial protein (Oda et al, 2005). Homologues of NAPlr are also present on the surface of commensal oral streptococci, which also bind and activate plasmin(ogen) Jones and Holt, 2004). Transient bacteremia with oral streptococci is frequent in humans (Daly et al, 1997;Roberts et al, 1997;Westling et al, 2002), but not associated with PSGN.…”

Section: Factors Involved In Psgnmentioning

confidence: 99%