| 1. |
- Jönsson, Daniel, et al.
(författare)
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Gingival tissue transcriptomes in experimental gingivitis.
- 2011
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Ingår i: Journal of clinical periodontology. - : John Wiley & Sons. - 1600-051X .- 0303-6979. ; 38:7, s. 599-611
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the sequential gene expression in the gingiva during the induction and resolution of experimental gingivitis.
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| 2. |
- Dahlstrom, M., et al.
(författare)
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Affinity states of biocides determine bioavailability and release rates in marine paints
- 2015
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Ingår i: Biofouling. - : Informa UK Limited. - 0892-7014 .- 1029-2454. ; 31:2, s. 201-210
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Tidskriftsartikel (refereegranskat)abstract
- A challenge for the next generation marine antifouling (AF) paints is to deliver minimum amounts of biocides to the environment. The candidate AF compound medetomidine is here shown to be released at very low concentrations, ie ng ml(-1) day(-1). Moreover, the release rate of medetomidine differs substantially depending on the formulation of the paint, while inhibition of barnacle settlement is independent of release to the ambient water, ie the paint with the lowest release rate was the most effective in impeding barnacle colonisation. This highlights the critical role of chemical interactions between biocide, paint carrier and the solid/aqueous interface for release rate and AF performance. The results are discussed in the light of differential affinity states of the biocide, predicting AF activity in terms of a high surface affinity and preserved bioavailability. This may offer a general framework for the design of low-release paint systems using biocides for protection against biofouling on marine surfaces.
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| 3. |
- Vahasarja, N., et al.
(författare)
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Infective Endocarditis Among High-risk Individuals Before and After the Cessation of Antibiotic Prophylaxis in Dentistry: A National Cohort Study
- 2022
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press (OUP). - 1058-4838 .- 1537-6591. ; 75:7
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Tidskriftsartikel (refereegranskat)abstract
- The findings of this cohort study suggest no increased incidence of oral streptococcal infective endocarditis among high-risk individuals in Sweden since the recommended cessation of antibiotic prophylaxis in dentistry for the prevention of endocarditis in October 2012. Background A few years after the publication of the British guidelines, national recommendations were published by the Swedish Medical Products Agency in October 2012, promoting the cessation of antibiotic prophylaxis in dentistry for the prevention of infective endocarditis (IE). The aim of this study was to evaluate whether the incidence of oral streptococcal IE increased among high-risk individuals after October 2012. Methods This nationwide cohort study included all adult individuals (>17 years) living in Sweden from January 2008 to January 2018, with a diagnose code or surgical procedure code indicating high risk of IE. Cox proportional hazard models were performed to calculate adjusted ratios of oral streptococcal IE before and after October 2012 between high-risk individuals and references. Results This study found no increased incidence of oral streptococcal IE among high-risk individuals during the 5 years after the cessation, compared with before. Hazard rate ratios were 15.4 (95% confidence interval [CI]: 8.3-28.5) before and 20.7 (95% CI: 10.0-42.7) after October 2012 for prevalent high-risk individuals. Corresponding ratios for incident high-risk individuals were 66.8 (95% CI: 28.7-155.6) and 44.6 (95% CI: 22.9-86.9). Point estimates for interaction with time period were 1.4 (95% CI: .6-3.5) and 0.8 (95% CI: .5-1.3) for prevalent and incident high-risk individuals, respectively. Conclusion The results suggest that the current Swedish recommendation not to administer antibiotic prophylaxis for the prevention of IE in dentistry has not led to an increased incidence of oral streptococcal IE among high-risk individuals.
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| 4. |
- Basic, Amina, et al.
(författare)
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The proteins of Fusobacterium spp. involved in hydrogen sulfide production from L-cysteine
- 2017
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Ingår i: Bmc Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 17:61
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hydrogen sulfide (H2S) is a toxic foul-smelling gas produced by subgingival biofilms in patients with periodontal disease and is suggested to be part of the pathogenesis of the disease. We studied the H2S-producing protein expression of bacterial strains associated with periodontal disease. Further, we examined the effect of a cysteine-rich growth environment on the synthesis of intracellular enzymes in F. nucleatum polymorphum ATCC 10953. The proteins were subjected to one-dimensional (1DE) and two-dimensional (2DE) gel electrophoresis An in-gel activity assay was used to detect the H2S-producing enzymes; Sulfide from H2S, produced by the enzymes in the gel, reacted with bismuth forming bismuth sulfide, illustrated as brown bands (1D) or spots (2D) in the gel. The discovered proteins were identified with liquid chromatography - tandem mass spectrometry (LC-MS/MS). Results: Cysteine synthase and proteins involved in the production of the coenzyme pyridoxal 5'phosphate (that catalyzes the production of H2S) were frequently found among the discovered enzymes. Interestingly, a higher expression of H2S-producing enzymes was detected from bacteria incubated without cysteine prior to the experiment. Conclusions: Numerous enzymes, identified as cysteine synthase, were involved in the production of H2S from cysteine and the expression varied among Fusobacterium spp. and strains. No enzymes were detected with the in-gel activity assay among the other periodontitis-associated bacteria tested. The expression of the H2S-producing enzymes was dependent on environmental conditions such as cysteine concentration and pH but less dependent on the presence of serum and hemin.
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| 5. |
- Svärd, Anna, 1985-, et al.
(författare)
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Protein-Functionalized Gold Nanoparticles as Refractometric Nanoplasmonic Sensors for the Detection of Proteolytic Activity of Porphyromonas gingivalis
- 2020
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society. - 2574-0970. ; 3:10, s. 9822-9830
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Tidskriftsartikel (refereegranskat)abstract
- Periodontitis is an inflammatory oral disease that affects a large part of the adult population, causing significant costs and suffering. The key pathogen, Porphyromonas gingivalis, secretes gingipains, which are highly destructive proteases and the most important virulence factors in the pathogenesis of the disease. Currently, periodontitis is diagnosed mainly by mechanical manual probing and radiography, often when the disease has already progressed significantly. The possibilities of detecting gingipain activity in gingival fluid could enable early-stage diagnosis and facilitate treatment. Here, we describe a sensitive nanoparticle-based nanoplasmonic biosensor for the detection of the proteolytic activity of gingipains. Gold nanoparticles (AuNPs) were self-assembled as a submonolayer in multiwell plates and further modified with casein or IgG. The proteolytic degradation of the protein coating was tracked by monitoring the shift in the localized surface plasmon resonance (LSPR) peak position. The sensor performance was investigated using model systems with trypsin and purified gingipains (subtypes Kgp and RgpB) and further validated using supernatants from cultures of P. gingivalis. Proteolytic degradation by proteases in buffer results in a concentration- and time-dependent blueshift of the LSPR band of about 1-2 nm when using casein as a substrate. In bacterial supernatants, the degradation of the protein coating resulted in unspecific binding of proteins present in the complex sample matrix to the nanoparticles, which instead triggered a redshift of about 2 nm of the LSPR band. A significant LSPR shift was seen only in samples with gingipain activity. The sensor showed a limit of detection < 0.1 mu g/mL (4.3 nM), which is well below gingipain concentrations detected in severe chronic periodontitis cases (similar to 50 mu g/mL). This work shows the possibility of developing cost-effective nanoparticle-based biosensors for rapid detection of protease activity for chair-side periodontal diagnostics.
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| 6. |
- Lönn, Johanna, et al.
(författare)
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Lipoprotein modifications by gingipains of Porphyromonas gingivalis
- 2018
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Ingår i: Journal of Periodontal Research. - : Wiley-Blackwell Publishing Inc.. - 0022-3484 .- 1600-0765. ; 53:3, s. 403-413
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND OBJECTIVE: Several studies have shown an association between periodontitis and cardiovascular disease (CVD). Atherosclerosis is the major cause of CVD, and a key event in the development of atherosclerosis is accumulation of lipoproteins within the arterial wall. Bacteria are the primary etiologic agents in periodontitis and Porphyromonas gingivalis is the major pathogen in the disease. Several studies support a role of modified low-density lipoprotein (LDL) in atherogenesis; however, the pathogenic stimuli that induce the changes and the mechanisms by which this occur are unknown. This study aims to identify alterations in plasma lipoproteins induced by the periodontopathic species of bacterium, P. gingivalis, in vitro.MATERIAL AND METHODS: Plasma lipoproteins were isolated from whole blood treated with wild-type and gingipain-mutant (lacking either the Rgp- or Kgp gingipains) P. gingivalis by density/gradient-ultracentrifugation and were studied using 2-dimensional gel electrophoresis followed by matrix-assisted laser desorption/ionization mass spectrometry. Porphyromonas gingivalis-induced lipid peroxidation and antioxidant levels were measured by thiobarbituric acid-reactive substances and antioxidant assay kits, respectively, and lumiaggregometry was used for measurement of reactive oxygen species (ROS) and aggregation.RESULTS: Porphyromonas gingivalis exerted substantial proteolytic effects on the lipoproteins. The Rgp gingipains were responsible for producing 2 apoE fragments, as well as 2 apoB-100 fragments, in LDL, and the Kgp gingipain produced an unidentified fragment in high-density lipoproteins. Porphyromonas gingivalis and its different gingipain variants induced ROS and consumed antioxidants. Both the Rgp and Kgp gingipains were involved in inducing lipid peroxidation.CONCLUSIONS: Porphyromonas gingivalis has the potential to change the expression of lipoproteins in blood, which may represent a crucial link between periodontitis and CVD.
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| 7. |
- Hadzic, Radinka, et al.
(författare)
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alpha1-Antitrypsin inhibits Moraxella catarrhalis MID protein-induced tonsillar B cell proliferation and IL-6 release.
- 2006
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Ingår i: Immunology Letters. - : Elsevier BV. - 0165-2478 .- 1879-0542. ; 102:2, s. 141-147
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Tidskriftsartikel (refereegranskat)abstract
- alpha 1-Antitrypsin (AAT) is a major circulating and tissues inhibitor of serine proteinases implicated in the regulation of inflammation and host defence. There is now increasing evidence that AAT may also exhibit anti-inflammatory activities independent of its protease inhibitor function. This study was undertaken to investigate the effects of native (inhibitory) and polymerized (non-inhibitory) forms of AAT on MID (Moraxella IgD binding protein)-induced human tonsillar B cell activation in vitro. We found that 0.5 mu g/ml MID induces B cell proliferation and stimulates IL-6 release (p < 0.001) relative to non-stimulated controls. Both native and polymerized AAT (0.5 mg/ml) inhibited MID-stimulated B cell proliferation in a similar manner (by 70%, p < 0.001), whereas MID-induced IL-6 release was more strongly suppressed by polymefized (9.9-fold, p < 0.001) as compared to native AAT (2.8-fold, p < 0.01). Electrophoretic analysis of cell culture media did not indicate any interaction between AAT and MID, and flow cytometry data showed no competition for the same receptor. The effects of AATs were observed whether added together with MID or 2 h after MID-addition to cell cultures. Thus, our data demonstrate that AAT inhibits MID-induced B cell activation in vitro that is unrelated to its protease inhibitory activity and is not dependent on MID binding to the cell surface.
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| 8. |
- Bengtsson, Torbjörn, 1955-, et al.
(författare)
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The lantibiotic gallidermin acts bactericidal against Staphylococcus epidermidis and Staphylococcus aureus and antagonizes the bacteria-induced proinflammatory responses in dermal fibroblasts
- 2018
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Ingår i: MicrobiologyOpen. - : John Wiley & Sons. - 2045-8827. ; 7:6
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Tidskriftsartikel (refereegranskat)abstract
- Antimicrobial resistance needs to be tackled from new angles, and antimicrobial peptides could be future candidates for combating bacterial infections. This study aims to investigate in vitro the bactericidal effects of the lantibiotic gallidermin on Staphylococcus epidermidis and Staphylococcus aureus, possible cytotoxic effects and its impact on host-microbe interactions. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of gallidermin were determined, and cytotoxicity and proinflammatory effects of gallidermin on fibroblasts, red blood cells (RBCs) and in whole blood were investigated. Both MIC and MBC for all four tested strains of S. epidermidis was 6.25 μg/ml. Both MIC and MBC for methicillin-sensitive S. aureus was 12.5 μg/ml and for methicillin-resistant S. aureus (MRSA) 1.56 μg/ml. Gallidermin displayed no cytotoxic effects on fibroblasts, only a high dose of gallidermin induced low levels of CXCL8 and interleukin-6. Gallidermin hemolyzed less than 1% of human RBCs, and did not induce reactive oxygen species production or cell aggregation in whole blood. In cell culture, gallidermin inhibited the cytotoxic effects of the bacteria and totally suppressed the bacteria-induced release of CXCL8 and interleukin-6 from fibroblasts. We demonstrate that gallidermin, expressing low cell cytotoxicity, is a promising candidate for treating bacterial infections caused by S. epidermidis and S. aureus, especially MRSA.
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| 9. |
- Movert, Elin, et al.
(författare)
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Streptococcal M protein promotes IL-10 production by cGAS-independent activation of the STING signaling pathway
- 2018
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Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7374 .- 1553-7366. ; 14:3
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Tidskriftsartikel (refereegranskat)abstract
- From an evolutionary point of view a pathogen might benefit from regulating the inflammatory response, both in order to facilitate establishment of colonization and to avoid life-threatening host manifestations, such as septic shock. In agreement with this notion Streptococcus pyogenes exploits type I IFN-signaling to limit detrimental inflammation in infected mice, but the host-pathogen interactions and mechanisms responsible for induction of the type I IFN response have remained unknown. Here we used a macrophage infection model and report that S. pyogenes induces anti-inflammatory IL-10 in an M protein-dependent manner, a function that was mapped to the B- and C-repeat regions of the M5 protein. Intriguingly, IL-10 was produced downstream of type I IFN-signaling, and production of type I IFN occurred via M protein-dependent activation of the STING signaling pathway. Activation of STING was independent of the cytosolic double stranded DNA sensor cGAS, and infection did not induce detectable release into the cytosol of either mitochondrial, nuclear or bacterial DNA–indicating DNA-independent activation of the STING pathway in S. pyogenes infected macrophages. These findings provide mechanistic insight concerning how S. pyogenes induces the type I IFN response and identify a previously unrecognized macrophage-modulating role for the streptococcal M protein that may contribute to curb the inflammatory response to infection.
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| 10. |
- Wickström, Claes, et al.
(författare)
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Proteolytic degradation of human salivary MUC5B by dental biofilms.
- 2009
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Ingår i: Microbiology. - : Microbiology Society. - 1465-2080 .- 1350-0872.
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Tidskriftsartikel (refereegranskat)abstract
- The degradation of complex substrates, like salivary mucins, requires an arsenal of glycosidases and proteases to sequentially degrade the oligosaccharides and polypeptide backbone. MUC5B is a complex oligomeric glycoprotein, heterogeneous in molecular mass (14-40 x 106 Da), with a diverse repertoire of oligosaccharides, differing in composition and charge. The aim of this study was to investigate whether proteolytic degradation of the mucin polypeptide backbone could be identified and if cooperation of dental biofilm bacteria was required. Cooperative bacterial-mediated proteolysis of MUC5B was determined by comparing individual and mixed consortia of strains isolated from supragingival plaque and freshly harvested supragingival plaque. Proteolytic activity was analyzed using fluorescent labelled substrate and by visualizing mucin degradation by SDS-PAGE. Dental plaque degraded the polypeptide backbone of the salivary MUC5B mucin. The mucin also was degraded by a specific consortium of isolated species from supragingival plaque, although individual species and other consortia did not. Select bacteria in supragingival dental plaque, therefore, cooperate as a consortium to proteolyze human salivary MUC5B and hydrolyze glycosides.
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