| 1. |
- Eskilson, Olof, 1992-, et al.
(författare)
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Nanocellulose composite wound dressings for real-time pH wound monitoring
- 2023
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Ingår i: Materials Today Bio. - : Elsevier. - 2590-0064. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- The skin is the largest organ of the human body. Wounds disrupt the functions of the skin and can have catastrophic consequences for an individual resulting in significant morbidity and mortality. Wound infections are common and can substantially delay healing and can result in non-healing wounds and sepsis. Early diagnosis and treatment of infection reduce risk of complications and support wound healing. Methods for monitoring of wound pH can facilitate early detection of infection. Here we show a novel strategy for integrating pH sensing capabilities in state-of-the-art hydrogel-based wound dressings fabricated from bacterial nanocellulose (BC). A high surface area material was developed by self-assembly of mesoporous silica nanoparticles (MSNs) in BC. By encapsulating a pH-responsive dye in the MSNs, wound dressings for continuous pH sensing with spatiotemporal resolution were developed. The pH responsive BC-based nanocomposites demonstrated excellent wound dressing properties, with respect to conformability, mechanical properties, and water vapor transmission rate. In addition to facilitating rapid colorimetric assessment of wound pH, this strategy for generating functional BC-MSN nanocomposites can be further be adapted for encapsulation and release of bioactive compounds for treatment of hard-to-heal wounds, enabling development of novel wound care materials.
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| 2. |
- Eskilson, Olof, 1992-, et al.
(författare)
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Self-Assembly of Mechanoplasmonic Bacterial Cellulose-Metal Nanoparticle Composites
- 2020
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlagsgesellschaft. - 1616-301X .- 1616-3028. ; 30:40
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Tidskriftsartikel (refereegranskat)abstract
- Nanocomposites of metal nanoparticles (NPs) and bacterial nanocellulose (BC) enable fabrication of soft and biocompatible materials for optical, catalytic, electronic, and biomedical applications. Current BC-NP nanocomposites are typically prepared by in situ synthesis of the NPs or electrostatic adsorption of surface functionalized NPs, which limits possibilities to control and tune NP size, shape, concentration, and surface chemistry and influences the properties and performance of the materials. Here a self-assembly strategy is described for fabrication of complex and well-defined BC-NP composites using colloidal gold and silver NPs of different sizes, shapes, and concentrations. The self-assembly process results in nanocomposites with distinct biophysical and optical properties. In addition to antibacterial materials and materials with excellent senor performance, materials with unique mechanoplasmonic properties are developed. The homogenous incorporation of plasmonic gold NPs in the BC enables extensive modulation of the optical properties by mechanical stimuli. Compression gives rise to near-field coupling between adsorbed NPs, resulting in tunable spectral variations and enhanced broadband absorption that amplify both nonlinear optical and thermoplasmonic effects and enables novel biosensing strategies.
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| 3. |
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| 4. |
- Bengtsson, Torbjörn, 1955-, et al.
(författare)
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Dual action of bacteriocin PLNC8 alpha beta through inhibition of Porphyromonas gingivalis infection and promotion of cell proliferation
- 2017
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Ingår i: Pathogens and Disease. - : Oxford University Press. - 2049-632X. ; 75:5
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Tidskriftsartikel (refereegranskat)abstract
- Periodontitis is a chronic inflammatory disease that is characterised by accumulation of pathogenic bacteria, including Porphyromonas gingivalis, in periodontal pockets. The lack of effective treatments has emphasised in an intense search for alternative methods to prevent bacterial colonisation and disease progression. Bacteriocins are bacterially produced antimicrobial peptides gaining increased consideration as alternatives to traditional antibiotics. We show rapid permeabilisation and aggregation of P. gingivalis by the two-peptide bacteriocin PLNC8 alpha beta. In a cell culture model, P. gingivalis was cytotoxic against gingival fibroblasts. The proteome profile of fibroblasts is severely affected by P. gingivalis, including induction of the ubiquitin-proteasome pathway. PLNC8 alpha beta enhanced the expression of growth factors and promoted cell proliferation, and suppressed proteins associated with apoptosis. PLNC8 alpha beta efficiently counteracted P. gingivalis-mediated cytotoxicity, increased expression of a large number of proteins and restored the levels of inflammatory mediators. In conclusion, we show that bacteriocin PLNC8 alpha beta displays dual effects by acting as a potent antimicrobial agent killing P. gingivalis and as a stimulatory factor promoting cell proliferation. We suggest preventive and therapeutical applications of PLNC8 alpha beta in periodontitis to supplement the host immune defence against P. gingivalis infection and support wound healing processes.
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| 5. |
- Bengtsson, Torbjörn, 1955-, et al.
(författare)
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Secreted gingipains from Porphyromonas gingivalis colonies exert potent immunomodulatory effects on human gingival fibroblasts
- 2015
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Ingår i: Microbiological Research. - : Elsevier BV. - 0944-5013 .- 1618-0623. ; 178, s. 18-26
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Tidskriftsartikel (refereegranskat)abstract
- Periodontal pathogens, including Polphyromonas gingivalis, can form biofilms in dental pockets and cause inflammation, which is one of the underlying mechanisms involved in the development of periodontal disease, ultimately leading to tooth loss. Although P. gingivalis is protected in the biofilm, it can still cause damage and modulate inflammatory responses from the host, through secretion of microvesicles containing proteinases. The aim of this study was to evaluate the role of cysteine proteinases in P. gingivalis colony growth and development, and subsequent immunomodulatory effects on human gingival fibroblast. By comparing the wild type W50 with its gingipain deficient strains we show that cysteine proteinases are required by P. gingivalis to form morphologically normal colonies. The lysine-specific proteinase (Kgp), but not arginine-specific proteinases (Rgps), was associated with immunomodulation. P. gingivalis with Kgp affected the viability of gingival fibroblasts and modulated host inflammatory responses, including induction of TGF-beta 1 and suppression of CXCL8 and IL-6 accumulation. These results suggest that secreted products from P. gingivalis, including proteinases, are able to cause damage and significantly modulate the levels of inflammatory mediators, independent of a physical host-bacterial interaction. This study provides new insight of the pathogenesis of P. gingivalis and suggests gingipains as targets for diagnosis and treatment of periodontitis.
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| 6. |
- Karlsson, Mattias, 1981-, et al.
(författare)
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Substances released from probiotic Lactobacillus rhamnosus GR-1 potentiate NF-κB activity in Escherichia coli-stimulated urinary bladder cells
- 2012
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Ingår i: FEMS Immunology and Medical Microbiology. - Hoboken, USA : Wiley-Blackwell. - 0928-8244 .- 1574-695X. ; 66:2, s. 147-156
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Tidskriftsartikel (refereegranskat)abstract
- Lactobacillus rhamnosus GR-1 is a probiotic bacterium used to maintain urogenital health. The putative mechanism for its probiotic effect is by modulating the host immunity. Urinary tract infections (UTI) are often caused by uropathogenic Escherichia coli that frequently evade or suppress immune responses in the bladder and can target pathways, including nuclear factor-kappaB (NF-κB). We evaluated the role of L. rhamnosus GR-1 on NF-κB activation in E. coli-stimulated bladder cells. Viable L. rhamnosus GR-1 was found to potentiate NF-κB activity in E. coli-stimulated T24 bladder cells, whereas heat-killed lactobacilli demonstrated a marginal increase in NF-κB activity. Surface components released by trypsin- or LiCl treatment, or the resultant heat-killed shaved lactobacilli, had no effect on NF-κB activity. Isolation of released products from L. rhamnosus GR-1 demonstrated that the induction of NF-κB activity was owing to released product(s) with a relatively large native size. Several putative immunomodulatory proteins were identified, namely GroEL, elongation factor Tu and NLP/P60. GroEL and elongation factor Tu have previously been shown to elicit immune responses from human cells. Isolating and using immune-augmenting substances produced by lactobacilli is a novel strategy for the prevention or treatment of UTI caused by immune-evading E. coli.
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| 7. |
- Omer, Abubakr A. M., 1982-, et al.
(författare)
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Plantaricin NC8 αβ rapidly and efficiently inhibits flaviviruses and SARS-CoV-2 by disrupting their envelopes
- 2022
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 17:11
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Tidskriftsartikel (refereegranskat)abstract
- Potent broad-spectrum antiviral agents are urgently needed to combat existing and emerging viral infections. This is particularly important considering that vaccine development is a costly and time consuming process and that viruses constantly mutate and render the vaccine ineffective. Antimicrobial peptides (AMP), such as bacteriocins, are attractive candidates as antiviral agents against enveloped viruses. One of these bacteriocins is PLNC8 αβ, which consists of amphipathic peptides with positive net charges that display high affinity for negatively charged pathogen membrane structures, including phosphatidylserine rich lipid membranes of viral envelopes. Due to the morphological and physiological differences between viral envelopes and host cell plasma membranes, PLNC8 αβ is thought to have high safety profile by specifically targeting viral envelopes without effecting host cell membranes. In this study, we have tested the antiviral effects of PLNC8 αβ against the flaviviruses Langat and Kunjin, coronavirus SARS-CoV-2, influenza A virus (IAV), and human immunodeficiency virus-1 (HIV-1). The concentration of PLNC8 αβ that is required to eliminate all the infective virus particles is in the range of nanomolar (nM) to micromolar (μM), which is surprisingly efficient considering the high content of cholesterol (8–35%) in their lipid envelopes. We found that viruses replicating in the endoplasmic reticulum (ER)/Golgi complex, e.g. SARS-CoV-2 and flaviviruses, are considerably more susceptible to PLNC8 αβ, compared to viruses that acquire their lipid envelope from the plasma membrane, such as IAV and HIV-1. Development of novel broad-spectrum antiviral agents can significantly benefit human health by rapidly and efficiently eliminating infectious virions and thereby limit virus dissemination and spreading between individuals. PLNC8 αβ can potentially be developed into an effective and safe antiviral agent that targets the lipid compartments of viral envelopes of extracellular virions, more or less independent of virus antigenic mutations, which faces many antiviral drugs and vaccines.
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| 8. |
- Wiman, Emanuel, 1985-, et al.
(författare)
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Development of novel broad-spectrum antimicrobial lipopeptides derived from plantaricin NC8 β
- 2023
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Bacterial resistance towards antibiotics is a major global health issue. Very few novel antimicrobial agents and therapies have been made available for clinical use during the past decades, despite an increasing need. Antimicrobial peptides have been intensely studied, many of which have shown great promise in vitro. We have previously demonstrated that the bacteriocin Plantaricin NC8 αβ (PLNC8 αβ) from Lactobacillus plantarum effectively inhibits Staphylococcus spp., and shows little to no cytotoxicity towards human keratinocytes. However, due to its limitations in inhibiting gram-negative species, the aim of the present study was to identify novel antimicrobial peptidomimetic compounds with an enhanced spectrum of activity, derived from the β peptide of PLNC8 αβ. We have rationally designed and synthesized a small library of lipopeptides with significantly improved antimicrobial activity towards both gram-positive and gram-negative bacteria, including the ESKAPE pathogens. The lipopeptides consist of 16 amino acids with a terminal fatty acid chain and assemble into micelles that effectively inhibit and kill bacteria by permeabilizing their cell membranes. They demonstrate low hemolytic activity and liposome model systems further confirm selectivity for bacterial lipid membranes. The combination of lipopeptides with different antibiotics enhanced the effects in a synergistic or additive manner. Our data suggest that the novel lipopeptides are promising as future antimicrobial agents, however additional experiments using relevant animal models are necessary to further validate their in vivo efficacy.
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| 9. |
- Bengtsson, Torbjörn, 1955-, et al.
(författare)
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Plantaricin NC8 αβ exerts potent antimicrobial activity against Staphylococcus spp. and enhances the effects of antibiotics
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- The use of conventional antibiotics has substantial clinical efficacy, however these vital antimicrobial agents are becoming less effective due to the dramatic increase in antibiotic-resistant bacteria. Novel approaches to combat bacterial infections are urgently needed and bacteriocins represent a promising alternative. In this study, the activities of the two-peptide bacteriocin PLNC8 αβ were investigated against different Staphylococcus spp. The peptide sequences of PLNC8 α and β were modified, either through truncation or replacement of all L-amino acids with D-amino acids. Both L- and D-PLNC8 αβ caused rapid disruption of lipid membrane integrity and were effective against both susceptible and antibiotic resistant strains. The D-enantiomer was stable against proteolytic degradation by trypsin compared to the L-enantiomer. Of the truncated peptides, β1-22, β7-34 and β1-20 retained an inhibitory activity. The peptides diffused rapidly (2 min) through the bacterial cell wall and permeabilized the cell membrane, causing swelling with a disorganized peptidoglycan layer. Interestingly, sub-MIC concentrations of PLNC8 αβ substantially enhanced the effects of different antibiotics in an additive or synergistic manner. This study shows that PLNC8 αβ is active against Staphylococcus spp. and may be developed as adjuvant in combination therapy to potentiate the effects of antibiotics and reduce their overall use.
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| 10. |
- 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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| 11. |
- Davies, Julia R, 1962-, et al.
(författare)
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Polymicrobial synergy stimulates Porphyromonas gingivalis survival and gingipain expression in a multi-species subgingival community
- 2021
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Ingår i: BMC Oral Health. - : BioMed Central. - 1472-6831. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Dysbiosis in subgingival microbial communities, resulting from increased inflammatory transudate from the gingival tissues, is an important factor in initiation and development of periodontitis. Dysbiotic communities are characterized by increased numbers of bacteria that exploit the serum-like transudate for nutrients, giving rise to a proteolytic community phenotype. Here we investigate the contribution of interactions between members of a sub-gingival community to survival and development of virulence in a serum environment-modelling that in the subgingival pocket.METHODS: Growth and proteolytic activity of three Porphyromonas gingivalis strains in nutrient broth or a serum environment were assessed using A600 and a fluorescent protease substrate, respectively. Adherence of P. gingivalis strains to serum-coated surfaces was studied with confocal microscopy and 2D-gel electrophoresis of bacterial supernatants used to investigate extracellular proteins. A model multi-species sub-gingival community containing Fusobacterium nucleatum, Streptococcus constellatus, Parvimonas micra with wild type or isogenic mutants of P. gingivalis was then created and growth and proteolytic activity in serum assessed as above. Community composition over time was monitored using culture techniques and qPCR.RESULTS: The P. gingivalis strains showed different growth rates in nutrient broth related to the level of proteolytic activity (largely gingipains) in the cultures. Despite being able to adhere to serum-coated surfaces, none of the strains was able to grow alone in a serum environment. Together in the subgingival consortium however, all the included species were able to grow in the serum environment and the community adopted a proteolytic phenotype. Inclusion of P. gingivalis strains lacking gingipains in the consortium revealed that community growth was facilitated by Rgp gingipain from P. gingivalis.CONCLUSIONS: In the multi-species consortium, growth was facilitated by the wild-type and Rgp-expressing strains of P. gingivalis, suggesting that Rgp is involved in delivery of nutrients to the whole community through degradation of complex protein substrates in serum. Whereas they are constitutively expressed by P. gingivalis in nutrient broth, gingipain expression in the model periodontal pocket environment (serum) appeared to be orchestrated through signaling to P. gingivalis from other members of the community, a phenomenon which then promoted growth of the whole community.
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| 12. |
- Elmarghani, Ahmed, 1975-, et al.
(författare)
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Contribution of pharmaceuticals, fecal bacteria and endotoxin to the inflammatory responses to inland waters
- 2014
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 488-489, s. 228-235
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Tidskriftsartikel (refereegranskat)abstract
- The increasing contamination of freshwater with pharmaceuticals, surfactants, pesticides and other organic compounds are of major concern. As these contaminants are detected at trace levels in the environment it is important to determine if they elicit biological responses at the observed levels. In addition to chemical pollutants, there is also a concern for increasing levels of bacteria and other microorganisms in freshwater systems. In an earlier study, we observed the activation of inflammatory systems downstream of a wastewater treatment plant (WWTP) in southern Sweden. We also observed that the water contained unidentified components that were pro-inflammatory and potentiated the immune response in human urinary bladder epithelial cells. In order to determine if these effects were unique for the studied site or represent a common response in Swedish water, we have now performed a study on three WWTPs and their recipient waters in central Sweden. Analysis of immune responses in urinary bladder epithelial cells, monocyte-like cells and blood mononuclear cells confirm that these waters activate the immune system as well as induce pro-inflammatory responses. The results indicate that the cytokine profiles correlate to the endotoxin load of the waters rather than to the levels of pharmaceuticals or culturable bacteria load, suggesting that measurements of endotoxin levels and immune responses would be a valuable addition to the analysis of inland waters.
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| 13. |
- Fursatz, Marian, et al.
(författare)
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Functionalization of bacterial cellulose wound dressings with the antimicrobial peptide ε-poly-L-Lysine
- 2018
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Ingår i: Biomedical Materials. - : Institute of Physics Publishing (IOPP). - 1748-6041 .- 1748-605X. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Wound dressings based on bacterial cellulose (BC) can form a soft and conformable protective layer that can stimulate wound healing while preventing bacteria from entering the wound. Bacteria already present in the wound can, however, thrive in the moist environment created by the BC dressing which can aggravate the healing process. Possibilities to render the BC antimicrobial without affecting the beneficial structural and mechanical properties of the material would hence be highly attractive. Here we present methods for functionalization of BC with ε-Poly-L-Lysine (ε-PLL), a non-toxic biopolymer with broad-spectrum antimicrobial activity. Low molecular weight ε-PLL was cross-linked in pristine BC membranes and to carboxymethyl cellulose (CMC) functionalized BC using carbodiimide chemistry. The functionalization of BC with ε-PLL inhibited growth of S. epidermidis on the membranes but did not affect the cytocompatibility to cultured human fibroblasts as compared to native BC. The functionalization had no significant effects on the nanofibrous structure and mechanical properties of the BC. The possibility to functionalize BC with ε-PLL is a promising, green and versatile approach to improve the performance of BC in wound care and other biomedical applications.
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| 14. |
- Jayaprakash, Kartheyaene, 1983-, et al.
(författare)
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Gingipains from Porphyromonas gingivalis play a significant role in induction and regulation of CXCL8 in THP-1 cells
- 2014
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Ingår i: BMC Microbiology. - : BioMed Central. - 1471-2180. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Porphyromonas gingivalis is an important bacterial etiological agent involved in periodontitis. The bacterium expresses two kinds of cysteine proteases called gingipains: arginine gingipains (RgpA/B) and lysine gingipain (Kgp). This study evaluated the interaction between P. gingivalis and THP-1 cells, a widely used monocytic cell line, in vitro with a focus on CXCL8 at the gene and protein levels and its fate thereafter in cell culture supernatants. THP-1 cells were stimulated with viable and heat-killed wild-type strains ATCC 33277 or W50 or viable isogenic gingipain mutants of W50, E8 (Rgp mutant) or K1A (Kgp mutant), for 24 hours.Results: ELISA and qPCR results show an elevated CXCL8 expression and secretion in THP-1 cells in response to P. gingivalis, where the heat-killed ATCC33277 and W50 induced higher levels of CXCL8 in comparison to their viable counterparts. Furthermore, the Kgp-deficient mutant K1A caused a higher CXCL8 response compared to the Rgp-deficient E8. Chromogenic quantification of lipopolysaccharide (LPS) in supernatant showed no significant differences between viable and heat killed bacteria except that W50 shed highest levels of LPS. The wild-type strains secreted relatively more Rgp during the co-culture with THP-1 cells. The CXCL8 degradation assay of filter-sterilized supernatant from heat-killed W50 treated cells showed that Rgp was most efficient at CXCL8 hydrolysis. Of all tested P. gingivalis strains, adhesion and internalization in THP-1 cells was least conspicuous by Rgp-deficient P. gingivalis (E8), as demonstrated by confocal imaging.Conclusions: W50 and its Kgp mutant K1A exhibit a higher immunogenic and proteolytic function in comparison to the Rgp mutant E8. Since K1A differs from E8 in the expression of Rgp, it is rational to conclude that Rgp contributes to immunomodulation in a more dynamic manner in comparison to Kgp. Also, W50 is a more virulent strain when compared to the laboratory strain ATCC33277.
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| 15. |
- Jayaprakash, Kartheyaene, 1983-, et al.
(författare)
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PKC, ERK/p38 MAP kinases and NF-B targeted signalling play a role in the expression and release of IL-1β and CXCL8 in Porphyromonas gingivalis-infected THP1 cells
- 2017
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : John Wiley & Sons. - 0903-4641 .- 1600-0463. ; 125:7, s. 623-633
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Tidskriftsartikel (refereegranskat)abstract
- Porphyromonas gingivalis is a keystone pathogen in periodontitis and is gaining importance in cardiovascular pathogenesis. Protease-activated receptors (PARs), toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD) on monocytes recognize the structural components on P. gingivalis, inducing inflammatory intermediates. Here, we elucidate the modulation of PARs, TLRs, NODs, and the role of MAPK and NF-B in IL-1 and CXCL8 release. THP1 cells were stimulated with P. gingivalis wild-type W50 and its isogenic gingipain mutants: Rgp mutant E8 and Kgp mutant K1A. We observed modulation of PARs, TLRs, NOD, IL-1 and CXCL8 expression by P. gingivalis. Gingipains hydrolyse IL-1 and CXCL8, which is more evident for IL-1 accumulation at 24 h. Inhibition of PKC (protein kinase C), p38 and ERK (extracellular signal-regulated kinases) partially reduced P. gingivalis-induced IL-1 at 6 h, whereas PKC and ERK reduced CXCL8 at both 6 and 24 h. Following NF-B inhibition, P. gingivalis-induced IL-1 and CXCL8 were completely suppressed to basal levels. Overall, TLRs, PARs and NOD possibly act in synergy with PKC, MAPK ERK/p38 and NF-B in P. gingivalis-induced IL-1 and CXCL8 release from THP1 cells. These pro-inflammatory cytokines could affect leucocytes in circulation and exacerbate other vascular inflammatory conditions such as atherosclerosis.
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| 16. |
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| 17. |
- Jayaprakash, Kartheyaene, et al.
(författare)
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Porphyromonas gingivalis-induced inflammatory responses in THP1 cells are altered by native and modified low-density lipoproteins in a strain-dependent manner
- 2018
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley-Blackwell Publishing Inc.. - 0903-4641 .- 1600-0463. ; 126:8, s. 667-677
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Tidskriftsartikel (refereegranskat)abstract
- Strong epidemiological evidence supports an association between cardiovascular and periodontal disease and furthermore, the periodontopathogen Porphyromonas gingivalis has been identified in blood and from atheromatous plaques. Blood exposed to P.gingivalis shows an increased protein modification of low-density lipoprotein (LDL). In this study, we investigate the inflammatory responses of THP1 cells incubated with P.gingivalis and the effects of native or modified LDL on these responses. Reactive oxygen species (ROS) and IL-1 were observed in THP1 cells following infection with P.gingivalis ATCC33277 and W50. Caspase 1 activity was quantified in THP1 cells and correlated with IL-1 accumulation. Oxidized LDL (oxLDL) induced IL-1 release and CD36 expression on THP1 cells. Modified LDL co-stimulated with ATCC33277 exhibited regulatory effects on caspase 1 activity, IL-1 release and CD36 expression in THP1 cells, whereas W50 induced more modest responses in THP1 cells. In summary, we show that P.gingivalis is capable of inducing pro-inflammatory responses in THP1 cells, and native and modified LDL could alter these responses in a dose- and strain-dependent manner. Strain-dependent differences in THP1 cell responses could be due to the effect of P.gingivalis proteases, presence or absence of capsule and proteolytic transformation of native and modified LDL.
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| 18. |
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| 19. |
- Jayaprakash, Kartheyaene, 1983-, et al.
(författare)
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The role of phagocytosis, oxidative burst and neutrophil extracellular traps in the interaction between neutrophils and the periodontal pathogen Porphyromonas gingivalis
- 2015
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Ingår i: Molecular Oral Microbiology. - : Wiley. - 2041-1006 .- 2041-1014. ; 30:5, s. 361-375
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Tidskriftsartikel (refereegranskat)abstract
- Neutrophils are regarded as the sentinel cells of innate immunity and are found in abundance within the gingival crevice. Discovery of neutrophil extracellular traps (NETs) within the gingival pockets prompted us to probe the nature of the interactions of neutrophils with the prominent periopathogen Porphyromonas gingivalis. Some of the noted virulence factors of this Gram-negative anaerobe are gingipains: arginine gingipains (RgpA/B) and lysine gingipain (Kgp). The aim of this study was to evaluate the role of gingipains in phagocytosis, formation of reactive oxygen species, NETs and CXCL8 modulation by using wild-type strains and isogenic gingipain mutants. Confocal imaging showed that gingipain mutants K1A (Kgp) and E8 (RgpA/B) induced extracellular traps in neutrophils, whereas ATCC33277 and W50 were phagocytosed. The viability of both ATCC33277 and W50 dwindled as the result of phagocytosis and could be salvaged by cytochalasin D, and the bacteria released high levels of lipopolysaccharide in the culture supernatant. Porphyromonas gingivalis induced reactive oxygen species and CXCL8 with the most prominent effect being that of the wild-type strain ATCC33277, whereas the other wild-type strain W50 was less effective. Quantitative real-time polymerase chain reaction revealed a significant CXCL8 expression by E8. All the tested P.gingivalis strains increased cytosolic free calcium. In conclusion, phagocytosis is the primary neutrophil response to P.gingivalis, although NETs could play an accessory role in infection control. Although gingipains do not seem to directly regulate phagocytosis, NETs or oxidative burst in neutrophils, their proteolytic properties could modulate the subsequent outcomes such as nutrition acquisition and survival by the bacteria.
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| 20. |
- Khalaf, Hazem, 1981-, et al.
(författare)
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Altered T-cell responses by the periodontal pathogen Porphyromonas gingivalis
- 2012
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Ingår i: PLOS ONE. - San Francisco, USA : Public Library Science. - 1932-6203. ; 7:9
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Tidskriftsartikel (refereegranskat)abstract
- Several studies support an association between the chronic inflammatory diseases periodontitis and atherosclerosis with a crucial role for the periodontal pathogen Porphyromonas gingivalis. However, the interplay between this pathogen and the adaptive immune system, including T-cells, is sparsely investigated. Here we used Jurkat T-cells to determine the effects of P. gingivalis on T-cell-mediated adaptive immune responses. We show that viable P. gingivalis targets IL-2 expression at the protein level. Initial cellular events, including ROS production and [Ca2+]i, were elevated in response to P. gingivalis, but AP-1 and NF-κB activity dropped below basal levels and T-cells were unable to sustain stable IL-2 accumulation. IL-2 was partially restored by Leupeptin, but not by Cathepsin B Inhibitor, indicating an involvement of Rgp proteinases in the suppression of IL-2 accumulation. This was further confirmed by purified Rgp that caused a dose-dependent decrease in IL-2 levels. These results provide new insights of how this periodontal pathogen evades the host adaptive immune system by inhibiting IL-2 accumulation and thus attenuating T-cell proliferation and cellular communication.
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| 21. |
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| 22. |
- Khalaf, Hazem, 1981-, et al.
(författare)
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Antibacterial effects of Lactobacillus and bacteriocin PLNC8 αβ on the periodontal pathogen Porphyromonas gingivalis
- 2016
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Ingår i: BMC Microbiology. - London, United Kingdom : BioMed Central (BMC). - 1471-2180. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: The complications in healthcare systems associated with antibiotic-resistant microorganisms have resulted in an intense search for new effective antimicrobials. Attractive substances from which novel antibiotics may be developed are the bacteriocins. These naturally occurring peptides are generally considered to be safe and efficient at eliminating pathogenic bacteria. Among specific keystone pathogens in periodontitis, Porphyromonas gingivalis is considered to be the most important pathogen in the development and progression of chronic inflammatory disease. The aim of the present study was to investigate the antimicrobial effects of different Lactobacillus species and the two-peptide bacteriocin PLNC8 αβ on P. gingivalis.Results: Growth inhibition of P. gingivalis was obtained by viable Lactobacillus and culture media from L. plantarum NC8 and 44048, but not L. brevis 30670. The two-peptide bacteriocin from L. plantarum NC8 (PLNC8 αβ) was found to be efficient against P. gingivalis through binding followed by permeabilization of the membranes, using Surface plasmon resonance analysis and DNA staining with Sytox Green. Liposomal systems were acquired to verify membrane permeabilization by PLNC8 αβ. The antimicrobial activity of PLNC8 αβ was found to be rapid (1 min) and visualized by TEM to cause cellular distortion through detachment of the outer membrane and bacterial lysis.Conclusion: Soluble or immobilized PLNC8 αβ bacteriocins may be used to prevent P. gingivalis colonization and subsequent pathogenicity, and thus supplement the host immune system against invading pathogens associated with periodontitis.
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| 23. |
- Khalaf, Hazem, 1981-, et al.
(författare)
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Cellular Response Mechanisms in Porphyromonas gingivalis Infection
- 2017
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Ingår i: Periodontitis. - : InTech. - 9789535136064 - 9789535136057 ; , s. 45-68
-
Bokkapitel (refereegranskat)abstract
- The pathogenicity of the periodontal biofilm is highly dependent on a few key species, of which Porphyromonas gingivalis is considered to be one of the most important pathogens. P. gingivalis expresses a broad range of virulence factors, of these cysteine proteases (gingipains) are of special importance both for the bacterial survival/proliferation and for the pathological outcome. Several cell types, for example, epithelial cells, endothelial cells, dendritic cells, osteoblasts, and fibroblasts, reside in the periodontium and are part of the innate host response, as well as platelets, neutrophils, lymphocytes, and monocytes/macrophages. These cells recognize and respond to P. gingivalis and its components through pattern recognition receptors (PRRs), for example, Toll-like receptors and protease-activated receptors. Ligation of PRRs induces downstream-signaling pathways modifying the activity of transcription factors that regulates the expression of genes linked to inflammation. This is followed by the release of inflammatory mediators, for example, cytokines and reactive oxygen species. Periodontal disease is today considered to play a significant role in various systemic conditions such as cardiovascular disease (CVD). The mechanisms by which P. gingivalis and its virulence factors interact with host immune cells and contribute to the pathogenesis of periodontitis and CVD are far from completely understood.
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| 24. |
- Khalaf, Hazem, 1981-, et al.
(författare)
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Cytokines and chemokines are differentially expressed in patients with periodontitis : Possible role for TGF-beta 1 as a marker for disease progression
- 2014
-
Ingår i: Cytokine. - London : Academic Press. - 1043-4666 .- 1096-0023. ; 67:1, s. 29-35
-
Tidskriftsartikel (refereegranskat)abstract
- Periodontitis is a chronic inflammatory disease characterized by destruction of periodontal tissue ultimately leading to bone destruction and has been associated with other inflammatory diseases, such as atherosclerosis. Attachment loss of periodontal tissue is primarily caused by host cell-derived immune responses against subgingival biofilm. The aim of the present study was to determine the cytokine profile in serum, saliva and gingival crevicular fluid (GCF) patients with periodontitis and healthy controls. We show that periodontitis patients exhibit higher numbers of periodontal pathogens and their immune responses are significantly altered. The levels of IL-6 in saliva and GCF were significantly suppressed, and while CXCL8 was not altered in serum, its expression levels were significantly suppressed in saliva and elevated in GCF. The T-cell-derived cytokine IL-2 did not differ between patients and controls in serum and saliva, but there was a significant suppression in GCF of patients. Interestingly, TGF-beta(1) levels were significantly elevated in serum, saliva and GCF in patients compared to controls. Furthermore, by using cultured gingival fibroblasts stimulated with wild type and proteinase mutant strains of Porphyromonas gingivalis, we show that the suppression of CXCL8 and IL-6, and the induction of TGF-beta(1) is primarily mediated by the proteolytic activity of lysine-specific proteinases. These results indicate that P. gingivalis is a major contributor to the altered immune responses and the pathology of periodontitis. Furthermore, the ease of sampling and analyzing cytokine expression profiles, including TGF-beta(1), in saliva and GCF may serve to predict the progression of periodontitis and associated systemic inflammatory diseases.
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| 25. |
- Khalaf, Hazem, 1981-, et al.
(författare)
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Suppression of inflammatory gene expression in T cells by Porphyromonas gingivalis is mediated by targeting MAPK signaling
- 2013
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Ingår i: Cellular & Molecular Immunology. - London, United Kingdom : Nature Publishing Group. - 1672-7681 .- 2042-0226. ; 10:5, s. 413-422
-
Tidskriftsartikel (refereegranskat)abstract
- There is increasing awareness of the effects of Porphyromonas gingivalis on host immune responses. Degradation of cytokines and chemokines by cysteine proteinases has previously been reported. However, the precise mechanisms by which P. gingivalis is able to alter intracellular signaling, and thus proliferation and inflammation, have not been described. We have previously reported suppression of activator protein-1 (AP-1) and degradation of IL-2 by proteinases from P. gingivalis. In the present study, we have analyzed the effects of P. gingivalis on Jurkat T-cell signal transduction and subsequent IL-2 and CXCL8 expression. We found that CXCL8, but not IL-2, gene expression levels were significantly suppressed by viable P. gingivalis. Analysis of intracellular signaling revealed an inhibitory effect of P. gingivalis on c-Jun and c-Fos, but not NF kappa B (p50 and p65), NFAT or STAT5 expression. This inhibitory effect was not due to suppression of mitogen-activated protein kinase (MAPK) (p38, erk and JNK) gene expression, but was rather due to prevention of protein kinase C (PKC) and p38 phosphorylation, as demonstrated by western blot analysis. Furthermore, SOCS1 and SOCS3 expression levels decreased following treatment of Jurkat T cells with viable P. gingivalis. The results indicate that P. gingivalis is able to suppress inflammatory gene expression by targeting the activity of MAPK pathways in T cells, which was confirmed by using specific inhibitors of NF-kappa B, PKC, ERK, p38 and JNK.
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| 26. |
- Khalaf, Hazem, 1981-, et al.
(författare)
-
The role of calcium, NF-κB and NFAT in the regulation of CXCL8 and IL-6 expression in Jurkat T-cells
- 2013
-
Ingår i: International Journal of Biochemistry and Molecular Biology. - 2152-4114. ; 4:3, s. 150-156
-
Tidskriftsartikel (refereegranskat)abstract
- T-cells play an important role in host immunity against invading pathogens. Determining the underlying regulatory mechanisms will provide a better understanding of T-cell-derived immune responses. In this study, we have shown the differential regulation of IL-6 and CXCL8 by NF-κB and NFAT in Jurkat T-cells, in response to PMA, heat killed Escherichia coli and calcium. CXCL8 was closely associated with the activation pattern of NFAT, while IL-6 expression was associated with NF-κB. Furthermore, increasing the intracellular Ca(2+) concentration by calcium ionophore treatment of the cells resulted in NFAT induction without affecting the NF-κB activity. Interestingly, NF-κB activation by heat killed E. coli, as well as CXCL8 and IL-6 expression was significantly suppressed following addition of the calcium ionophore. This indicates that calcium plays an important role in regulating protein trafficking and T-cell signalling, and the subsequent inflammatory gene expression infers an involvement of NFAT in CXCL8 regulation.Understanding these regulatory patterns provide clarification of conditions that involve altered intracellular signalling leading to T-cell-derived cytokine expression.
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| 27. |
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| 28. |
- Klarström-Engström, Kristin, 1986-, et al.
(författare)
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The role of Porphyromonas gingivalis gingipains in platelet activation and innate immune modulation
- 2015
-
Ingår i: Molecular Oral Microbiology. - : Wiley. - 2041-1006 .- 2041-1014. ; 30:1, s. 62-73
-
Tidskriftsartikel (refereegranskat)abstract
- Platelets are considered to have important functions in inflammatory processes and as actors in the innate immunity. Several studies have shown associations between cardiovascular disease and periodontitis, where the oral anaerobic pathogen Porphyromonas gingivalis has a prominent role in modulating the immune response. Porphyromonas gingivalis has been found in atherosclerotic plaques, indicating spreading of the pathogen via the circulation, with an ability to interact with and activate platelets via e.g. Toll-like receptors (TLR) and protease-activated receptors. We aimed to evaluate how the cysteine proteases, gingipains, of P.gingivalis affect platelets in terms of activation and chemokine secretion, and to further investigate the mechanisms of platelet-bacteria interaction. This study shows that primary features of platelet activation, i.e. changes in intracellular free calcium and aggregation, are affected by P.gingivalis and that arg-gingipains are of great importance for the ability of the bacterium to activate platelets. The P.gingivalis induced a release of the chemokine RANTES, however, to a much lower extent compared with the TLR2/1-agonist Pam(3)CSK(4), which evoked a time-dependent release of the chemokine. Interestingly, the TLR2/1-evoked response was abolished by a following addition of viable P.gingivalis wild-types and gingipain mutants, showing that both Rgp and Kgp cleave the secreted chemokine. We also demonstrate that Pam(3)CSK(4)-stimulated platelets release migration inhibitory factor and plasminogen activator inhibitor-1, and that also these responses were antagonized by P.gingivalis. These results supports immune-modulatory activities of P.gingivalis and further clarify platelets as active players in innate immunity and in sensing bacterial infections, and as target cells in inflammatory reactions induced by P.gingivalis infection.
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| 29. |
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| 30. |
- Musa, Amani, 1983-, et al.
(författare)
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Plantaricin NC8 alpha beta prevents Staphylococcus aureus-mediated cytotoxicity and inflammatory responses of human keratinocytes
- 2021
-
Ingår i: Scientific Reports. - : Nature Portfolio. - 2045-2322. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- Multidrug resistance bacteria constitue an increasing global health problem and the development of novel therapeutic strategies to face this challenge is urgent. Antimicrobial peptides have been proven as potent agents against pathogenic bacteria shown by promising in vitro results. The aim of this study was to characterize the antimicrobial effects of PLNC8 alpha beta on cell signaling pathways and inflammatory responses of human keratinocytes infected with S. aureus. PLNC8 alpha beta did not affect the viability of human keratinocytes but upregulated several cytokines (IL-1 beta, IL-6, CXCL8), MMPs (MMP1, MMP2, MMP9, MMP10) and growth factors (VEGF and PDGF-AA), which are essential in cell regeneration. S. aureus induced the expression of several inflammatory mediators at the gene and protein level and PLNC8 alpha beta was able to significantly suppress these effects. Intracellular signaling events involved primarily c-Jun via JNK, c-Fos and NF kappa B, suggesting their essential role in the initiation of inflammatory responses in human keratinocytes. PLNC8 alpha beta was shown to modulate early keratinocyte responses, without affecting their viability. The peptides have high selectivity towards S. aureus and were efficient at eliminating the bacteria and counteracting their inflammatory and cytotoxic effects, alone and in combination with low concentrations of gentamicin. We propose that PLNC8 alpha beta may be developed to combat infections caused by Staphylococcus spp.
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| 31. |
- Musa, Amani, 1983-
(författare)
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Plantaricins as a novel group of antibacterial compounds and enhancers of antibiotics
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Antibiotics have revolutionized medicine, however, the rapid development of an-tibiotic resistance among bacteria is diminishing their efficacy. Antimicrobial pep-tides produced by Lactobacillus plantarum, i.e., plantaricins, are considered prom-ising alternatives to antibiotics against infections. In this thesis, the antimicrobial activities of different plantaricins (Pln A, Pln EF, Pln JK, and PLNC8 αβ) were investigated against antibiotic-resistant and susceptible strains of Staphylococcus spp, biofilm-forming strains, as well as clinical isolates of ESKAPE pathogens, and Escherichia coli. Moreover, the stability, cytotoxicity, and immunomodulatory effects of PLNC8 αβ were characterized. The results show that Pln EF and Pln JK have potent antimicrobial activity against Staphylococcus epidermidis and effectively enhance the effects of various antibiotics. Furthermore, PLNC8 αβ shows potent antibacterial effects against different Gram-positive and Gram-negative bacteria, including vancomycin- and methicillin-resistant strains. The antibacterial effects and stability following peptide truncation and D-amino acid substitution were investigated. D-amino acid substitution did not change the antimicrobial activity of PLNC8 αβ, however, it increased the stability of the peptide as it was more resistant to proteolysis by trypsin compared to the native L-enantiomer. Moreover, among the truncated peptides, α1–22, β7–34, and β1–20 retained bacteriostatic effects without displaying bactericidal activity. L-PLNC8 αβ peptides were tested for their antibiofilm properties and displayed rapid disruption of surface-associated S. epidermidis. Electron microscopy shows that PLNC8 αβ targets bacterial cell membranes, ultimately resulting in rapid permeabilization and altered homeostasis, including ATP release. PLNC8 αβ does not show any cytotoxic or hemolytic effects on human cells in vitro. Furthermore, PLNC8 αβ counteracted the cytotoxic effects and expression of inflammatory mediators that were induced by S. aureus, including MMPs and growth factors that are essential in cell regeneration. Pathogen recognition receptors (TLR2, TLR4, and PAR2), intracellular signaling events (c-Jun, c-Fos), and inflammatory mediators (IL-1β, IL-6, CXCL-8), that facilitate pathogen recognition, cell survival, and cellular communication, were all enhanced by the peptides. At sub-MIC concentrations, PLNC8 αβ enhanced the activity of various antibiotics against both Gram-positive and Gram-negative ESKAPE bacteria. In conclusion, plantaricins efficiently impede bacterial pathogens and enhance the activity of antibiotics and thereby constitute a therapeutic option to counter the threatening situation with severe antibiotic-resistant infections.
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| 32. |
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| 33. |
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| 34. |
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| 35. |
- Palm, Eleonor, 1980-, et al.
(författare)
-
Porphyromonas gingivalis downregulates the immune response of fibroblasts
- 2013
-
Ingår i: BMC Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 13, s. 155-
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Porphyromonas gingivalis is a key pathogen in periodontitis, an inflammatory disease leading to destruction of bone and tooth-supporting tissue. P. gingivalis possesses a number of pathogenic properties to enhance growth and survival, including proteolytic gingipains. Accumulating data shows that gingipains are involved in the regulation of host inflammatory responses. The aim of this study was to determine if P. gingivalis infection modulates the inflammatory response of fibroblasts, including the release of chemokines and cytokines. Human gingival fibroblasts or primary dermal fibroblasts were pre-stimulated with tumor-necrosis factor-alpha (TNF-alpha) and cocultured with P. gingivalis. Gingipain inhibitors were used to explore the effect of gingipains. CXCL8 levels were determined with ELISA and the relative levels of various inflammatory mediators were determined by a cytokine assay.Results: TNF-alpha-triggered CXCL8 levels were completely abolished by viable P. gingivalis, whereas heat-killed P. gingivalis did not suppress CXCL8. Accumulation of CXCL8 was partially restored by an arginine-gingipain inhibitor. Furthermore, fibroblasts produced several inflammatory mediators, notably chemokines, all of which were suppressed by viable P. gingivalis.Conclusion: These findings provide evidence that fibroblast-derived inflammatory signals are modulated by heat-instable gingipains, whereby the bacteria can escape killing by the host immune system and promote its own growth and establishment. In addition, we show that fibroblasts are important mediators of inflammation in response to infection and thereby play a crucial role in determining the nature and magnitude of the invasion of immune cells.
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| 36. |
- Palm, Eleonor, 1980-, et al.
(författare)
-
Suppression of inflammatory responses of human gingival fibroblasts by gingipains from Porphyromonas gingivalis
- 2015
-
Ingår i: Molecular Oral Microbiology. - : Wiley. - 2041-1006 .- 2041-1014. ; 30:1, s. 74-85
-
Tidskriftsartikel (refereegranskat)abstract
- The interaction between human gingival fibroblasts (HGFs) and Porphyromonas gingivalis plays an important role in the development and progression of periodontitis. Porphyromonas gingivalis possesses several virulence factors, including cysteine proteases, the arginine-specific (Rgp) and lysine-specific (Kgp) gingipains. Studying the mechanisms that P.gingivalis, and its derived virulence, use to propagate and interact with host cells will increase the understanding of the development and progression of periodontitis. In this study, we aimed to elucidate how P.gingivalis influences the inflammatory events in HGFs regarding transforming growth factor-(1) (TGF-(1)), CXCL8, secretory leucocyte protease inhibitor (SLPI), c-Jun and indoleamine 2,3-dioxygenase (IDO). HGFs were inoculated for 6 and 24h with the wild-type strains ATCC 33277 and W50, two gingipain-mutants of W50 and heat-killed ATCC 33277. The P.gingivalis regulated CXCL8 and TGF-(1) in HGFs, and the kgp mutant gave significantly higher immune response with increased CXCL8 (P<0.001) and low levels of TGF-(1). We show that HGFs express and secrete SLPI, which was significantly suppressed by P.gingivalis (P<0.05). This suggests that by antagonizing SLPI, P.gingivalis contributes to the tissue destruction associated with periodontitis. Furthermore, we found that P.gingivalis inhibits the expression of the antimicrobial IDO, as well as upregulating c-Jun (P<0.05). In conclusion, P.gingivalis both triggers and suppresses the immune response in HGFs. Consequently, we suggest that the pathogenic effects of P.gingivalis, and especially the activity of the gingipains on the inflammatory and immune response of HGFs, are crucial in periodontitis.
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| 37. |
- Palm, Eleonor, 1980-, et al.
(författare)
-
The role of toll-like and protease-activated receptors and associated intracellular signaling in Porphyromonas gingivalis-infected gingival fibroblasts
- 2017
-
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - Hoboken, USA : Wiley-Blackwell Publishing Inc.. - 0903-4641 .- 1600-0463. ; 125:2, s. 157-169
-
Tidskriftsartikel (refereegranskat)abstract
- Porphyromonas gingivalis, which is considered a keystone agent in periodontitis, has evolved elaborate mechanisms to grow and survive in a hostile milieu. The gingival fibroblast is the major cell type in the gingiva and is considered to be important in the periodontitis-associated inflammation. As a part of the innate immune response, they produce cytokines such as CXCL8 and interleukin (IL)-6 which are believed to contribute to the destruction of the tooth-supporting tissues. This study investigates how the expression of protease-activated receptors (PAR1, PAR2) and toll-like receptors (TLR2, TLR4) changes with P. gingivalis exposure and how silencing of one receptor affects the expression of the other receptors. The importance of protein kinase C (PKC) and p38 in the regulation of CXCL8 and IL-6 was also examined. Receptors were knockdown with small-interfering RNA. PKC or p38 was blocked prior to stimulation with P. gingivalis. Fibroblasts were able to compensate for PAR1 knockdown with increased expression of PAR2. PKC and p38 were involved in the regulation of P. gingivalis-induced CXCL8 and IL-6. Our results indicate that PAR1 and PAR2 could be implicated in periodontitis and that PKC and P38 play a role in the inflammatory response in P. gingivalis-infected gingival fibroblasts.
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| 38. |
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| 39. |
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| 40. |
- Palm, Eleonor, 1980-, et al.
(författare)
-
The role of toll-like and protease-activated receptors in the expression of cytokines by gingival fibroblasts stimulated with the periodontal pathogen Porphyromonas gingivalis
- 2015
-
Ingår i: Cytokine. - : Academic Press. - 1043-4666 .- 1096-0023. ; 76:2, s. 424-432
-
Tidskriftsartikel (refereegranskat)abstract
- Porphyromonas gingivalis is a periodontitis-associated pathogen and interactions between the bacterium and gingival fibroblasts play an important role in development and progression of periodontitis, an inflammatory disease leading to degeneration of tooth-supporting structures. Gingival fibroblasts, which expresses protease activated receptors (PARs) as well as toll-like receptors (TLRs), produces inflammatory mediators upon bacterial challenges. In this study, we elucidated the importance of PAR1, PAR2, TLR2 and TLR4 for the expression and secretion of CXCL8, interleukin-6 (IL-6), transforming growth factor-beta 1 (TGF-beta 1) and secretory leukocyte inhibitor (SLPI). Human gingival fibroblasts were transfected with small-interfering RNA against the target genes, and then stimulated with P. gingivalis wild-type W50 and W50-derived double rgp mutant E8 and kgp mutant K1A. TLR2-silencing reduced P. gingivalis-induced CXCL8 and IL-6. IL-6 was also reduced after PAR1-silencing. No effects were observed for TGF-beta 1. SLPI was suppressed by P. gingivalis and silencing of PAR1 as well as TLR2, gave additional suppression at the mRNA level. TLR4 was not involved in the regulation of the investigated mediators. CXCL8 and IL-6 are important for progression and development of periodontitis, leading to a chronic inflammation that may contribute to the tissue destruction that follows an exacerbated host response. Therefore, regulating the expression of TLR2 and subsequent release of CXCL8 and IL-6 in periodontitis could attenuate the tissue destruction seen in periodontitis.
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| 41. |
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| 42. |
- Pradhan, Ajay, 1983-, et al.
(författare)
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Activation of NF-kappa B Protein Prevents the Transition from Juvenile Ovary to Testis and Promotes Ovarian Development in Zebrafish
- 2012
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Ingår i: Journal of Biological Chemistry. - : The American Society for Biochemistry and Molecular Biology. - 0021-9258 .- 1083-351X. ; 287:45, s. 37926-37938
-
Tidskriftsartikel (refereegranskat)abstract
- Testis differentiation in zebrafish involves juvenile ovary to testis transformation initiated by an apoptotic wave. The molecular regulation of this transformation process is not fully understood. NF-kappa B is activated at an early stage of development and has been shown to interact with steroidogenic factor-1 in mammals, leading to the suppression of anti-Mullerian hormone (Amh) gene expression. Because steroidogenic factor-1 and Amh are important for proper testis development, NF-kappa B-mediated induction of anti-apoptotic genes could, therefore, also play a role in zebrafish gonad differentiation. The aim of this study was to examine the potential role of NF-kappa B in zebrafish gonad differentiation. Exposure of juvenile zebrafish to heat-killed Escherichia coli activated the NF-kappa B pathways and resulted in an increased ratio of females from 30 to 85%. Microarray and quantitative real-time-PCR analysis of gonads showed elevated expression of NF-kappa B-regulated genes. To confirm the involvement of NF-kappa B-induced anti-apoptotic effects, zebrafish were treated with sodium deoxycholate, a known inducer of NF-kappa B or NF-kappa B activation inhibitor (NAI). Sodium deoxycholate treatment mimicked the effect of heat-killed bacteria and resulted in an increased proportion of females from 25 to 45%, whereas the inhibition of NF-kappa B using NAI resulted in a decrease in females from 45 to 20%. This study provides proof for an essential role of NF-kappa B in gonadal differentiation of zebrafish and represents an important step toward the complete understanding of the complicated process of sex differentiation in this species and possibly other cyprinid teleosts as well.
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| 43. |
- Selegård, Robert, et al.
(författare)
-
Plantaricins markedly enhance the effects of traditional antibiotics against Staphylococcus epidermidis
- 2019
-
Ingår i: Future Microbiology. - : Future Medicine. - 1746-0913 .- 1746-0921. ; 14:3, s. 195-206
-
Tidskriftsartikel (refereegranskat)abstract
- AIM: Bacteriocins are considered as promising alternatives to antibiotics against infections. In this study, the plantaricins (Pln) A, E, F, J and K were investigated for their antimicrobial activity against Staphylococcus epidermidis.MATERIALS & METHODS: The effects on membrane integrity were studied using liposomes and viable bacteria, respectively.RESULTS: We show that PlnEF and PlnJK caused rapid and significant lysis of S. epidermidis, and induced lysis of liposomes. The PlnEF and PlnJK displayed similar mechanisms by targeting and disrupting the bacterial cell membrane. Interestingly, Pln enhanced the effects of different antibiotics by 30- to 500-fold.CONCLUSION: This study shows that Pln in combination with low concentrations of antibiotics is efficient against S. epidermidis and may be developed as potential treatment of infections.
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| 44. |
- Squinca, Paula, et al.
(författare)
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Multifunctional Ginger Nanofiber Hydrogels with Tunable Absorption : The Potential for Advanced Wound Dressing Applications
- 2021
-
Ingår i: Biomacromolecules. - : MDPI. - 1525-7797 .- 1526-4602. ; 22:8, s. 3202-3215
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Tidskriftsartikel (refereegranskat)abstract
- In this study, ginger residue from juice production was evaluated as a raw material resource for preparation of nanofiber hydrogels with multifunctional properties for advanced wound dressing applications. Alkali treatment was applied to adjust the chemical composition of ginger fibers followed by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation prior to nanofiber isolation. The effect of alkali treatment on hydrogel properties assembled through vacuum filtration without addition of any chemical cross-linker was evaluated. An outstanding absorption ability of 6200% combined with excellent mechanical properties, tensile strength of 2.1 ± 0.2 MPa, elastic modulus of 15.3 ± 0.3 MPa, and elongation at break of 25.1%, was achieved without alkali treatment. Furthermore, the absorption capacity was tunable by applying alkali treatment at different concentrations and by adjusting the hydrogel grammage. Cytocompatibility evaluation of the hydrogels showed no significant effect on human fibroblast proliferation in vitro. Ginger essential oil was used to functionalize the hydrogels by providing antimicrobial activity, furthering their potential as a multifunctional wound dressing.
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| 45. |
- Wickham, Abeni, et al.
(författare)
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Electroactive biomimetic collagen-silver nanowire composite scaffolds
- 2016
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Ingår i: Nanoscale. - Cambridge : Royal Society of Chemistry. - 2040-3364 .- 2040-3372. ; 8:29, s. 14146-14155
-
Tidskriftsartikel (refereegranskat)abstract
- Electroactive biomaterials are widely explored as bioelectrodes and as scaffolds for neural and cardiac regeneration. Most electrodes and conductive scaffolds for tissue regeneration are based on synthetic materials that have limited biocompatibility and often display large discrepancies in mechanical properties with the surrounding tissue causing problems during tissue integration and regeneration. This work shows the development of a biomimetic nanocomposite material prepared from self-assembled collagen fibrils and silver nanowires (AgNW). Despite consisting of mostly type I collagen fibrils, the homogeneously embedded AgNWs provide these materials with a charge storage capacity of about 2.3 mC cm(-2) and a charge injection capacity of 0.3 mC cm(-2), which is on par with bioelectrodes used in the clinic. The mechanical properties of the materials are similar to soft tissues with a dynamic elastic modulus within the lower kPa range. The nanocomposites also support proliferation of embryonic cardiomyocytes while inhibiting the growth of both Gram-negative Escherichia coli and Gram-positive Staphylococcus epidermidis. The developed collagen/AgNW composites thus represent a highly attractive bioelectrode and scaffold material for a wide range of biomedical applications.
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| 46. |
- Zhang, Boxi, 1987-, et al.
(författare)
-
Gingipains from the Periodontal Pathogen Porphyromonas gingivalis Play a Significant Role in Regulation of Angiopoietin 1 and Angiopoietin 2 in Human Aortic Smooth Muscle Cells
- 2015
-
Ingår i: Infection and Immunity. - : American Society for Microbiology. - 0019-9567 .- 1098-5522. ; 83:11, s. 4256-4265
-
Tidskriftsartikel (refereegranskat)abstract
- Angiopoietin 1 (Angpt1) and angiopoietin 2 (Angpt2) are the ligands of tyrosine kinase (Tie) receptors, and they play important roles in vessel formation and the development of inflammatory diseases, such as atherosclerosis. Porphyromonas gingivalis is a Gram-negative periodontal bacterium that is thought to contribute to the progression of cardiovascular disease. The aim of this study was to investigate the role of P. gingivalis infection in the modulation of Angpt1 and Angpt2 in human aortic smooth muscle cells (AoSMCs). We exposed AoSMCs to wild-type (W50 and 381), gingipain mutant (E8 and K1A), and fimbrial mutant (DPG-3 and KRX-178) P. gingivalis strains and to different concentrations of tumor necrosis factor (TNF). The atherosclerosis risk factor TNF was used as a positive control in this study. We found that P. gingivalis (wild type, K1A, DPG3, and KRX178) and TNF upregulated the expression of Angpt2 and its transcription factor ETS1, respectively, in AoSMCs. In contrast, Angpt1 was inhibited by P. gingivalis and TNF. However, the RgpAB mutant E8 had no effect on the expression of Angpt1, Angpt2, or ETS1 in AoSMCs. The results also showed that ETS1 is critical for P. gingivalis induction of Angpt2. Exposure to Angpt2 protein enhanced the migration of AoSMCs but had no effect on proliferation. This study demonstrates that gingipains are crucial to the ability of P. gingivalis to markedly increase the expressed Angpt2/Angpt1 ratio in AoSMCs, which determines the regulatory role of angiopoietins in angiogenesis and their involvement in the development of atherosclerosis. These findings further support the association between periodontitis and cardiovascular disease.
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| 47. |
- Zhang, Boxi, 1987-, et al.
(författare)
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The periodontal pathogen Porphyromonas gingivalis changes the gene expression in vascular smooth muscle cells involving the TGFbeta/Notch signalling pathway and increased cell proliferation
- 2013
-
Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 14, s. 770-
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Porphyromonas gingivalis is a gram-negative bacterium that causes destructive chronic periodontitis. In addition, this bacterium is also involved in the development of cardiovascular disease. The aim of this study was to investigate the effects of P. gingivalis infection on gene and protein expression in human aortic smooth muscle cells (AoSMCs) and its relation to cellular function.Results: AoSMCs were exposed to viable P. gingivalis for 24 h, whereafter confocal fluorescence microscopy was used to study P. gingivalis invasion of AoSMCs. AoSMCs proliferation was evaluated by neutral red assay. Human genome microarray, western blot and ELISA were used to investigate how P. gingivalis changes the gene and protein expression of AoSMCs. We found that viable P. gingivalis invades AoSMCs, disrupts stress fiber structures and significantly increases cell proliferation. Microarray results showed that, a total of 982 genes were identified as differentially expressed with the threshold log2 fold change >|1| (adjust p-value <0.05). Using bioinformatic data mining, we demonstrated that up-regulated genes are enriched in gene ontology function of positive control of cell proliferation and down-regulated genes are enriched in the function of negative control of cell proliferation. The results from pathway analysis revealed that all the genes belonging to these two categories induced by P. gingivalis were enriched in 25 pathways, including genes of Notch and TGF-beta pathways.Conclusions: This study demonstrates that P. gingivalis is able to invade AoSMCs and stimulate their proliferation. The activation of TGF-beta and Notch signaling pathways may be involved in the bacteria-mediated proliferation of AoSMCs. These findings further support the association between periodontitis and cardiovascular diseases.
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| 48. |
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| 49. |
- Zhang, Boxi, 1987-, et al.
(författare)
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Transcriptional profiling of human smooth muscle cells infected with gingipain and fimbriae mutants of Porphyromonas gingivalis
- 2016
-
Ingår i: Scientific Reports. - London United Kingdom : Nature Publishing Group. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Porphyromonas gingivalis (P. gingivalis) is considered to be involved in the development of atherosclerosis. However, the role of different virulence factors produced by P. gingivalis in this process is still uncertain. The aim of this study was to investigate the transcriptional profiling of human aortic smooth muscle cells (AoSMCs) infected with wild type, gingipain mutants or fimbriae mutants of P. gingivalis. AoSMCs were exposed to wild type (W50 and 381), gingipain mutants (E8 and K1A), or fimbriae mutants (DPG-3 and KRX-178) of P. gingivalis. We observed that wild type P. gingivalis changes the expression of a considerable larger number of genes in AoSMCs compare to gingipain and fimbriae mutants, respectively. The results from pathway analysis revealed that the common differentially expressed genes for AoSMCs infected by 3 different wild type P. gingivalis strains were enriched in pathways of cancer, cytokine-cytokine receptor interaction, regulation of the actin cytoskeleton, focal adhesion, and MAPK signaling pathway. Disease ontology analysis showed that various strains of P. gingivalis were associated with different disease profilings. Our results suggest that gingipains and fimbriae, especially arginine-specific gingipain, produced by P. gingivalis play important roles in the association between periodontitis and other inflammatory diseases, including atherosclerosis.
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