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Query: UMLS:C0031099 (periodontitis)
 12,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Activities of cysteine and trypsin-like proteinase inhibitors and of cathepsin D were measured in mixed saliva of periodontitis patients with conditions of varying severity. Salivary proteinase inhibitor activities were found related, to a certain measure, to the severity of inflammation. Salivary antitryptic activity was somewhat reduced and cysteine proteinase inhibitor activity elevated in patients with non-severe periodontitis. In cases with medium-severe and severe periodontitis salivary proteinase activity was augmenting, approaching the normal value, whereas cysteine proteinase inhibitor level was significantly decreased. A reduction of salivary inhibitor activity was related to the formation of inhibitor-proteinase complexes, whereas a rise of this activity was explained by release of inhibitors from these complexes resulting from dissociation. This is possibly due to the formation of partially cleaved inhibitor form because of cathepsin effects.
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PMID:[The proteinase inhibitors of mixed saliva in periodontitis]. 185 78

Adhesive interactions of cells are critical to tissue integrity. We show that infection with Porphyromonas gingivalis, a major pathogen in the periodontal disease periodontitis, interferes with both cell-matrix and cell-cell adhesion in the oral keratinocyte cell line HOK-16. Thus, infected cells showed reduced adhesion to extracellular matrix, changes in morphology from spread to rounded, and impaired motility on purified matrices in Transwell migration assays and scratch assays. Western blot analysis of P. gingivalis-challenged HOK-16 cells revealed proteolysis of focal contact components (e.g., focal adhesion kinase), adherens junction proteins (e.g., catenins), and adhesion signaling molecules (e.g., the tyrosine kinase SRC). Proteolysis was selective, since important components of adherens junctions (E-cadherin) or signaling molecules (extracellular signal-regulated kinases ERK1/2) were not degraded. The virulence factors gingipains, cysteine proteinases expressed by P. gingivalis, are likely responsible for this proteolytic attack, since they directly digested specific proteins in pull-down experiments, and their proteolytic activity was blocked by the cysteine proteinase inhibitor N-alpha-p-tosyl-L-lysine chloromethyl ketone and also by a caspase inhibitor. Proteolysis was strain dependent, such that ATCC 33277 and 381 had high proteolytic potential, whereas W50 showed almost no proteolytic activity. These findings may help explain the formation of gingival pockets between cementum and periodontal epithelium, a hallmark of periodontitis. Furthermore, they illustrate a new pathogenetic paradigm of infection whereby bacteria may disrupt the integrity of epithelia.
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PMID:Discrete proteolysis of focal contact and adherens junction components in Porphyromonas gingivalis-infected oral keratinocytes: a strategy for cell adhesion and migration disabling. 1222 16

Anti-neutrophil cytoplasmic Abs targeting proteinase 3 (PR3) have been detected in relation to a wide range of inflammatory conditions such as periodontitis, and interaction of anti-PR3 Abs with endothelial and epithelial cells provokes cell activation, although the underlying mechanism has been unclear. The present study showed that human oral epithelial cells expressed PR3 mRNA after treatment with proinflammatory cytokines such as IL-1alpha, TNF-alpha, IFN-alpha, IFN-beta, and IFN-gamma. A 29-kDa PR3 was expressed on the cell surface and released into culture supernatants by the cells upon stimulation with these cytokines. The membrane and supernatant fractions of oral epithelial cells exhibited enzymatic activity, which was inhibited by serine proteinase inhibitors, but not by a cysteine proteinase inhibitor or secretory leukocyte protease inhibitor. Addition of anti-PR3 Abs to cytokine-primed oral epithelial cells in culture induced remarkable secretion of IL-8 and monocyte chemoattractant protein 1 and aggregation of PR3 on the cells. RNA interference targeted to protease-activated receptor-2 mRNA and intracellular Ca2+ mobilization assays revealed that anti-PR3 Abs activated the epithelial cells through protease-activated receptor-2, a family of G protein-coupled receptors. The anti-PR3 Ab-mediated cell activation was completely abolished by RNA interference targeted to PR3 mRNA and by inhibition of phospholipase C and NF-kappaB. Immunohistochemistry showed that inflamed oral epithelium actually expresses PR3 protein. These results suggest that oral epithelial cells express functional PR3 in the inflamed sites and respond to anti-PR3 Abs detected in diseased sera, and that these mechanisms may actively participate in the inflammatory process, including periodontitis.
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PMID:Proinflammatory cytokines induce proteinase 3 as membrane-bound and secretory forms in human oral epithelial cells and antibodies to proteinase 3 activate the cells through protease-activated receptor-2. 2030 35

Periodontitis is a response of highly vascularized tissues to the adjacent microflora of dental plaque. Progressive disease has been related to consortia of anaerobic bacteria, with the gram-negative organism Porphyromonas gingivalis particularly implicated. The gingipains, comprising a group of cysteine proteinases and associated hemagglutinin domains, are major virulence determinants of this organism. As vascular expression of leukocyte adhesion molecules is a critical determinant of tissue response to microbial challenge, the objective of this study was to determine the capacity of gingipains to modulate the expression and function of these receptors. Given the potential multifunctional role of platelet endothelial cell adhesion molecule 1 (PECAM-1) in the vasculature, the effect of gingipains on PECAM-1 expression by endothelial cells was examined. Activated gingipains preferentially down-regulated PECAM-1 expression on endothelial cells compared with vascular cell adhesion molecule 1 and endothelial-leukocyte adhesion molecule 1, but the reduction in PECAM-1 expression was completely inhibited in the presence of the cysteine proteinase inhibitor TLCK (Nalpha-p-tosyl-l-lysine chloromethyl ketone). Endothelial monolayers treated with activated gingipains demonstrated progressive intercellular gap formation that correlated with reduced intercellular junctional PECAM-1 expression as determined by Western blotting and immunofluorescence microscopy. This was accompanied by enhanced transfer of both albumin and neutrophils across the monolayer. The results suggest that degradation of PECAM-1 by gingipains contributes to increased vascular permeability and neutrophil flux at disease sites.
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PMID:Functional implication of the hydrolysis of platelet endothelial cell adhesion molecule 1 (CD31) by gingipains of Porphyromonas gingivalis for the pathology of periodontal disease. 1573 Oct 36

The role of Trichomonas tenax as a pathogen had been clearly implicated in various pathological processes that arise outside the boundaries of the mouth. Although a relationship between the increased occurrence of this protozoan and progression of periodontal disease has been demonstrated, the ability of T. tenax in causing oral infections and the precise mechanism of tissue damage is not well known. The present study aimed to investigate different isolates of T.tenax from individuals having oral infections. Plaques and/or calculi samples were collected from 70 individuals who were diagnosed as having periodontitis and/or gingivitis, then subjected to parasitological examination and culture on modified trypticase, yeast and iron medium (TYI-S-33). Isolates successfully maintained in culture were further subjected to analysis of protein profile of lysates by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) and analysis of proteinases by non-denaturing gelatin-SDS-PAGE. Comparison of growth kinetics of seven T. tenax isolates showed a wide variability in the growth characteristics. Protein profiles of the seven isolates revealed a total 53 bands ranged in molecular weight (MW) from 5 to 95kDa using 12% resolution gel. Also, T. tenax isolates were found to possess 19 proteinase bands ranged in MW from 14 to 66kDa. The proteolytic bands were intensified by a cysteine proteinase activator and totally disappeared by treatment with a cysteine proteinase inhibitor suggesting that the proteinases were of cysteine proteinases type. The high frequency of T. tenax detected (28.6%) along with the variability in protein profiling and proteolytic activity of the isolates supports the possible pathogenicity of T. tenax and clarifies a conclusion that different strains with possibility of variable pathogenic potential may exist.
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PMID:Growth kinetics, antigen profiling, and proteinase activity of Egyptian Trichomonas tenax isolates derived from patients having oral infections. 2234 32