Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 27
Filter
1.
Sci Rep ; 8(1): 17440, 2018 Nov 28.
Article in English | MEDLINE | ID: mdl-30487583

ABSTRACT

A method of fabricating multilayer focusing mirrors that can focus X-rays down to 10 nm or less was established in this study. The wavefront aberration induced by multilayer Kirkpatrick-Baez mirror optics was measured using a single grating interferometer at a photon energy of 9.1 keV at SPring-8 Angstrom Compact Free Electron Laser (SACLA), and the mirror shape was then directly corrected by employing a differential deposition method. The accuracies of these processes were carefully investigated, considering the accuracy required for diffraction-limited focusing. The wavefront produced by the corrected multilayer focusing mirrors was characterized again in the same manner, revealing that the root mean square of the wavefront aberration was improved from 2.7 (3.3) rad to 0.52 (0.82) rad in the vertical (horizontal) direction. A wave-optical simulator indicated that these wavefront-corrected multilayer focusing mirrors are capable of achieving sub-10-nm X-ray focusing.

2.
Phys Rev Lett ; 120(22): 223902, 2018 Jun 01.
Article in English | MEDLINE | ID: mdl-29906133

ABSTRACT

Nonlinear optical frequency conversion has been challenged to move down to the extreme ultraviolet and x-ray region. However, the extremely low signals have allowed researchers to only perform transmission experiments of the gas phase or ultrathin films. Here, we report second harmonic generation (SHG) of the reflected beam of a soft x-ray free-electron laser from a solid, which is enhanced by the resonant effect. The observation revealed that the double resonance condition can be met by absorption edges for transition metal oxides in the soft x-ray range, and this suggests that the resonant SHG technique can be applicable to a wide range of materials. We discuss the possibility of element-selective SHG spectroscopy measurements in the soft x-ray range.

3.
Oral Dis ; 23(4): 492-497, 2017 May.
Article in English | MEDLINE | ID: mdl-28083982

ABSTRACT

OBJECTIVE: Halitosis is caused by volatile sulphur compounds including methyl mercaptan (CH3 SH) in the oral cavity and is a serious problem that limits interpersonal social communication. The aim of study was to evaluate the effects of reuterin-related compounds (RRCs) on halitosis-related periodontopathic bacteria in vitro. MATERIALS AND METHODS: RRC-01, RRC-02 and RRC-03 (32 and 64 µg ml-1 ) in culture media containing Fusobacterium nucleatum JCM8523 and Porphyromonas gingivalis ATCC33277 were used. The effects of RRCs on CH3 SH production and detectable odour by F. nucleatum and P. gingivalis were examined by CH3 SH production assay and organoleptic test, respectively. The number of bacterial cells was also measured using an ATP assay. In P. gingivalis treated with RRCs, the expression of mgl gene, which is responsible for CH3 SH production, was examined by qRT-PCR. RESULTS: CH3 SH production and the score of detectable odour from F. nucleatum and P. gingivalis culture media containing RRCs were significantly lower than that without RRCs (P < 0.05). The expression of mgl gene in P. gingivalis was significantly downregulated by RRC-01 (P < 0.01), but not by RRC-02 or RRC-03. CONCLUSIONS: RRCs are potent oral care products for preventing halitosis via reducing CH3 SH production.


Subject(s)
Anti-Bacterial Agents/pharmacology , Fusobacterium nucleatum/drug effects , Glyceraldehyde/analogs & derivatives , Halitosis/microbiology , Odorants/analysis , Porphyromonas gingivalis/drug effects , Propane/pharmacology , Anti-Bacterial Agents/therapeutic use , Biomarkers/metabolism , Fusobacterium nucleatum/metabolism , Glyceraldehyde/pharmacology , Glyceraldehyde/therapeutic use , Halitosis/prevention & control , Humans , Porphyromonas gingivalis/metabolism , Propane/therapeutic use , Sulfhydryl Compounds/metabolism
4.
J Appl Microbiol ; 122(4): 893-899, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28035713

ABSTRACT

AIMS: Quaternary ammonium compounds (QACs), including benzalkonium chloride (BAC) and cetylpyridinium chloride (CPC) are cationic surfactants and have been used widely as general disinfectants in the medical field due to their strong antibacterial effects and low cytotoxicity to human cells. 4,4'-(α,ω-hexametylenedithio) bis (1-octylpyridinium bromide) (4DTBP-6,8) is one of the potent bis-QACs synthesized to improve the antimicrobial activities of mono-QACs such as BAC. This study aimed to assess the effectiveness of 4DTBP-6,8 against Pseudomonas aeruginosa, a prevalent hospital pathogen. METHODS AND RESULTS: The minimum inhibitory concentrations of 4DTBP-6,8, CPC and BAC against P. aeruginosa were measured. 4DTBP-6,8 exhibited strong antibacterial activity. We assessed the bactericidal effects of QACs against P. aeruginosa under certain conditions and their cytotoxicities in human epithelial cells using lactate dehydrogenase (LDH) release. 4DTBP-6,8 exerted excellent bactericidal effects against high concentrations of bacteria, biofilm cells and even in the presence of contaminated proteins. Cellular LDH was not released by the treatment with 4DTBP-6,8. CONCLUSIONS: 4DTBP-6,8 exhibited the strongest bactericidal activity against P. aeruginosa among the three QACs tested without any cytotoxicity. SIGNIFICANCE AND IMPACT OF THE STUDY: The potent bis-QAC, 4DTBP-6,8 has the potential to be an effective disinfectant in preventing hospital infections caused by P. aeruginosa.


Subject(s)
Anti-Bacterial Agents/pharmacology , Disinfectants/pharmacology , Niacinamide/analogs & derivatives , Pseudomonas aeruginosa/drug effects , Pyridinium Compounds/pharmacology , Biofilms/drug effects , Cell Line , Humans , Niacinamide/pharmacology
5.
J Appl Microbiol ; 122(2): 321-330, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27770500

ABSTRACT

Candida albicans is a commonly found member of the human microflora and is a major human opportunistic fungal pathogen. A perturbation of the microbiome can lead to infectious diseases caused by various micro-organisms, including C. albicans. Moreover, the interactions between C. albicans and bacteria are considered to play critical roles in human health. The major biological feature of C. albicans, which impacts human health, resides in its ability to form biofilms. In particular, the extracellular matrix (ECM) of Candida biofilm plays a multifaceted role and therefore may be considered as a highly attractive target to combat biofilm-related infectious diseases. In addition, extracellular DNA (eDNA) also plays a crucial role in Candida biofilm formation and its structural integrity and induces the morphological transition from yeast to the hyphal growth form during C. albicans biofilm development. This review focuses on pathogenic factors such as eDNA in Candida biofilm formation and its ECM production and provides meaningful information for future studies to develop a novel strategy to battle infectious diseases elicited by Candida-formed biofilm.


Subject(s)
Biofilms , Candida albicans/physiology , Candida/classification , Candida/physiology , Candida albicans/pathogenicity , Candidiasis/microbiology , DNA/metabolism , Humans , Hyphae/physiology , Quorum Sensing , Respiratory Tract Infections/microbiology , Virulence Factors/metabolism
6.
J Appl Microbiol ; 116(6): 1531-42, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24661775

ABSTRACT

AIMS: The aim of this study was to investigate the effects of genomic DNA purified from Candida albicans and pneumonia-related pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, on in vitro biofilm formation and morphological change of 3 Candida species (C. albicans, C. glabrata, and C. tropicalis). METHODS AND RESULTS: Biofilm formation was evaluated by the crystal violet assay and colony-forming unit counts. Morphological characteristics of biofilms were evaluated by scanning electron microscopy and fluorescence microscopy. Addition of DNA at a low concentration (<1·0 µg ml(-1)) significantly increased biofilm mass of all three Candida species. In contrast, the addition of DNA at a high concentration (10 µg ml(-1)) decreased the biofilm mass. Interestingly, the formation of hyphae in a dense network of yeast cells was observed in C. albicans biofilms exposed to a low concentration of DNA (<1·0 µg ml(-1)). CONCLUSIONS: These findings demonstrated that extracellular DNA (eDNA) plays a crucial role in Candida biofilm formation and suggested that eDNA may induce the morphological transition from yeast to hyphal growth form during C. albicans biofilm development. SIGNIFICANCE AND IMPACT OF THE STUDY: A novel therapy targeting eDNA may be applicable for Candida infection to decrease biofilm formation and hyphal formation.


Subject(s)
Biofilms/growth & development , Candida/growth & development , DNA, Fungal/metabolism , Candida albicans/genetics , Candida albicans/growth & development , Deoxyribonuclease I/pharmacology , Hyphae/growth & development , Microbial Viability , Microscopy, Electron, Scanning , Microscopy, Fluorescence
7.
J Synchrotron Radiat ; 21(Pt 1): 268-72, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24365948

ABSTRACT

The newly installed BL28XU beamline at SPring-8 is dedicated to in situ structural and electronic analysis of rechargeable batteries. It supports the time range (1 ms to 100 s) and spatial range (1 µm to 1 mm) needed for battery analysis. Electrochemical apparatus for battery charging and discharging are available in experimental hutches and in a preparation room. Battery analysis can be carried out efficiently and effectively using X-ray diffraction, X-ray absorption fine-structure analysis and hard X-ray photoelectron spectroscopy. Here, the design and performance of the beamline are described, and preliminary results are presented.

8.
J Appl Microbiol ; 115(1): 260-70, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23551549

ABSTRACT

AIMS: The aim of this study was to clarify the effects of homologous and heterologous extracellular DNAs (eDNAs) and histone-like DNA-binding protein (HLP) on Streptococcus intermedius biofilm development and rigidity. METHODS AND RESULTS: Formed biofilm mass was measured with 0·1% crystal violet staining method and observed with a scanning electron microscope. The localizations of eDNA and extracellular HLP (eHLP) in formed biofilm were detected by staining with 7-hydoxyl-9H-(1,3-dichloro-9,9-dimethylacridin-2-one) and anti-HLP antibody without fixation, respectively. DNase I treatment (200 U ml(-1)) markedly decreased biofilm formation and cell density in biofilms. Colocalization of eHLP and eDNA in biofilm was confirmed. The addition of eDNA (up to 1 µg ml(-1)) purified from Strep. intermedius, other Gram-positive bacteria, Gram-negative bacteria, or human KB cells into the Strep. intermedius culture increased the biofilm mass of all tested strains of Strep. intermedius, wild-type, HLP-downregulated strain and control strains. In contrast, the addition of eDNA (>1 µg ml(-1)) decreased the biofilm mass of all Strep. intermedius strains. CONCLUSIONS: These findings demonstrated that eDNA and eHLP play crucial roles in biofilm development and its rigidity. SIGNIFICANCE AND IMPACT OF THE STUDY: eDNA- and HLP-targeting strategies may be applicable to novel treatments for bacterial biofilm-related infectious diseases.


Subject(s)
Biofilms/growth & development , DNA-Binding Proteins/metabolism , DNA/pharmacology , Streptococcus intermedius/physiology , Biofilms/drug effects , Cell Line, Tumor , DNA/analysis , DNA-Binding Proteins/analysis , Deoxyribonuclease I , Humans , Streptococcus intermedius/drug effects , Streptococcus intermedius/growth & development
9.
J Appl Microbiol ; 113(1): 181-91, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22507081

ABSTRACT

AIMS: The aim of this work was to clarify the effects of electromagnetic wave irradiation (EMWI) on oral bacterial pathogens. METHODS AND RESULTS: A Gram-negative (Porphyromonas gingivalis) or Gram-positive (Streptococcus mutans, S. intermedius, Enterococcus faecalis) bacterial suspension was irradiated by EMW apparatus (500-1000 kHz, 5-15 times, 1 s time(-1) ). Quantification of survival bacteria by CFU counting revealed that EMWI exhibited marked bactericidal activity against all tested bacteria and bactericidal activity at 500 kHz increased in an irradiation number-dependent manner. After EMWI at 500 kHz, scanning electron microscopic observations showed that the chain of S. mutans cells was shortened after 5 irradiations and the outlines of bacterial cells (S. mutans and P. gingivalis) were unclear after 5-10 irradiations. EMWI inhibited the inductive effect of S. mutans on pro-inflammatory cytokine production in human monocytes and this inhibitory effect was comparable with that of heat-killed bacteria. Furthermore, using an enzyme activity assay, EMWI partially inactivated the activities of gingipains from P. gingivalis. CONCLUSIONS: These findings demonstrated that EMWI has inactivation and bactericidal activities against single microbial species among four kinds of oral pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: Electromagnetic wave irradiation may be applicable for medical disinfection and sterilization, such as refractory periapical periodontitis.


Subject(s)
Disinfection/methods , Electromagnetic Fields , Porphyromonas gingivalis/growth & development , Streptococcus mutans/growth & development , Adhesins, Bacterial/metabolism , Cell Line , Cysteine Endopeptidases/metabolism , Enterococcus faecalis/growth & development , Gingipain Cysteine Endopeptidases , Humans , Microbial Sensitivity Tests , Mouth/microbiology , Temperature
10.
J Periodontal Res ; 47(1): 55-61, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21895660

ABSTRACT

BACKGROUND AND OBJECTIVE: As epithelial cells function as a mechanical barrier, the permeability of the gingival epithelial cell layer indicates a defensive capability against invasion by periodontal pathogens. We have reported the expression of claudin-1 and E-cadherin, key regulators of permeability, in the gingival junctional epithelium. Irsogladine maleate (IM) is a medication for gastric ulcers and also regulates Aggregatibacter actinomycetemcomitans-stimuated chemokine secretion and E-cadherin expression in gingival epithelium. In this study, we have further investigated the effects of IM on the barrier functions of gingival epithelial cells under inflammatory conditions. MATERIAL AND METHODS: We examined the permeability, and the expression of claudin-1 and E-cadherin, in human gingival epithelial cells (HGECs) stimulated with tumor necrosis factor (TNF)-α, with or without IM. RESULTS: TNF-α increased the permeability of HGECs, and IM abolished the increase. TNF-α reduced the expression of E-cadherin in HGECs, and IM reversed the reduction. In addition, immunofluorescence staining showed that TNF-α disrupted claudin-1 expression in HGECs, and IM reversed this effect. CONCLUSION: The results suggest that IM reverses the TNF-α-induced disruption of the gingival epithelial barrier by regulating E-cadherin and claudin-1.


Subject(s)
Gingiva/drug effects , Triazines/pharmacology , Tumor Necrosis Factor-alpha/pharmacology , Adult , Blotting, Western , Cadherins/drug effects , Cell Culture Techniques , Cell Line , Cell Membrane Permeability/drug effects , Claudin-1 , Electric Impedance , Epithelial Attachment/cytology , Epithelial Attachment/drug effects , Epithelial Cells/drug effects , Epithelial Cells/immunology , Female , Fluorescein , Fluorescent Antibody Technique , Fluorescent Dyes , Gingiva/cytology , Gingiva/immunology , Humans , Male , Membrane Proteins/drug effects , Real-Time Polymerase Chain Reaction , Tight Junctions/drug effects , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Young Adult
11.
J Dent Res ; 90(7): 900-5, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21447697

ABSTRACT

Oral biofilms such as dental plaque cause dental caries and periodontitis, as well as aspiration pneumonia and infectious endocarditis by translocation. Hence, the suppression of oral biofilm formation is an issue of considerable importance. Mechanical removal, disinfectants, inhibition of polysaccharide formation, and artificial sugar have been used for the reduction of oral biofilm. From the viewpoint of the inhibition of bacterial adherence, we investigated whether aqueous biocompatible 2-methacryloyloxyethyl phosphorylcholine (MPC)-polymer can reduce streptococcal colonization and biofilm formation. We examined the effects of MPC-polymer on streptococcal adherence to saliva-coated hydroxyapatite and oral epithelial cells, and the adherence of Fusobacterium nucleatum to streptococcal biofilm. MPC-polymer application markedly inhibited both the adherence and biofilm formation of Streptococcus mutans on saliva-coated hydroxyapatite and streptococcal adherence to oral epithelial cells, and reduced the adherence of F. nucleatum to streptococcal biofilms. A small-scale clinical trial revealed that mouthrinsing with MPC-polymer inhibited the increase of oral bacterial numbers, especially of S. mutans. These findings suggest that MPC-polymer is a potent inhibitor of bacterial adherence and biofilm development, and may be useful to prevent dental-plaque-related diseases. (UMIN Clinical Trial Registry UMIN000003471).


Subject(s)
Bacterial Adhesion/drug effects , Biofilms/drug effects , Dental Plaque/prevention & control , Keratinocytes/microbiology , Methacrylates/pharmacology , Mouthwashes/pharmacology , Phosphorylcholine/analogs & derivatives , Streptococcus mutans/drug effects , Adult , Cell Line, Transformed , Dental Pellicle , Dental Plaque/microbiology , Durapatite , Fusobacterium nucleatum/drug effects , Humans , Methacrylates/therapeutic use , Mouth Mucosa/cytology , Mouth Mucosa/microbiology , Mouthwashes/therapeutic use , Phosphorylcholine/pharmacology , Phosphorylcholine/therapeutic use
12.
J Appl Microbiol ; 109(6): 2183-90, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20854456

ABSTRACT

AIMS: The major objective of the study was to evaluate the enhanced germicidal effects of low-frequency pulsed ultraviolet A (UVA)-light-emitting diode (LED) on biofilms. METHODS AND RESULTS: The germicidal effects of UVA-LED irradiation (365 nm, 0·28 mW cm(-2) , in pulsed or continuous mode) on Candida albicans or Escherichia coli biofilms were evaluated by determining colony-forming units. The morphological change of microbial cells in biofilms was observed using scanning electron microscopy. After 5-min irradiation, over 90% of viable micro-organisms in biofilms had been killed, and pulsed irradiation (1-1000 Hz) had significantly greater germicidal ability than continuous irradiation. Pulsed irradiation (100 Hz, 60 min) almost completely killed micro-organisms in biofilm (>99·9%), and 20-min irradiation greatly damaged both microbial species. Interestingly, few hyphae were found in irradiated Candida biofilms. Moreover, mannitol treatment, a scavenger of hydroxyl radicals (OH(•) ), significantly protected viable micro-organisms in biofilms from UVA-LED irradiation. CONCLUSIONS: The study demonstrated that pulsed UVA-LED irradiation has a strong germicidal effect (maximum at 100 Hz, over 5-min irradiation) and causes the disappearance of hyphal forms of Candida. SIGNIFICANCE AND IMPACT OF THE STUDY: This study can assist in developing a low-frequency pulsed UVA-LED system to be applied to pathogenic biofilms for disinfection.


Subject(s)
Biofilms/radiation effects , Candida albicans/radiation effects , Disinfection/methods , Escherichia coli/radiation effects , Ultraviolet Rays , Colony Count, Microbial , Free Radical Scavengers/pharmacology , Hydroxyl Radical/metabolism , Mannitol/pharmacology , Microbial Viability
13.
J Periodontal Res ; 45(2): 193-9, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20470259

ABSTRACT

BACKGROUND AND OBJECTIVE: Because human gingival fibroblasts (HGFs) are the predominant cells in periodontal tissues, we hypothesized that HGFs are contributed to receptors for components of bacteria. In this study, we focused on expression and function of nucleotide binding oligomerization domain 2 (NOD2) in HGFs, which is a mammalian cytosolic pathogen recognition molecule. MATERIAL AND METHODS: Expression of NOD2 in HGFs was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and flow cytometry. Production of interleukin (IL)-6, IL-8, cc chemokine ligand2, cxc chemokine ligand10 (CXCL10) and CXCL11 from HGFs was examined by enzyme-linked immunosorbent assay (ELISA). We used RT-PCR and immunohistochemistry to detect the NOD2 expression in human gingival tissues. RESULTS: We found clear NOD2 expression in HGFs. Upon stimulation with NOD2 agonist, muramyldipeptide (MDP), production of proinflammatory cytokines was enhanced. Moreover, MDP-induced production of proinflammatory cytokines was inhibited in a different manner by mitogen-activated protein kinase inhibitors and phosphatidylinositol 3-kinase inhibitor. Furthermore, MDP enhanced CXCL10 and CXCL11 productions by tumor necrosis factor-alpha (TNF-alpha)- or interferon-gamma (IFN-gamma)-stimulated HGFs, although MDP alone did not induce these chemokines. TNF-alpha and IFN-gamma increased NOD2 expression in HGFs. In addition, we detected NOD2 expression in mononuclear cells and HGFs in periodontally diseased tissues. CONCLUSION: These findings indicate that MDP which induces production of cytokines and chemokines from HGFs is related to the pathogenesis of periodontal disease.


Subject(s)
Acetylmuramyl-Alanyl-Isoglutamine/pharmacology , Fibroblasts/drug effects , Gingiva/drug effects , Inflammation Mediators/pharmacology , Nod2 Signaling Adaptor Protein/agonists , Adult , Anthracenes/pharmacology , Calcium-Calmodulin-Dependent Protein Kinases/antagonists & inhibitors , Cells, Cultured , Chemokine CCL2/analysis , Chemokine CCL2/drug effects , Chemokine CXCL10/analysis , Chemokine CXCL10/drug effects , Chemokine CXCL11/analysis , Chemokine CXCL11/drug effects , Chromones/pharmacology , Chronic Periodontitis/pathology , Enzyme Inhibitors/pharmacology , Female , Flavonoids/pharmacology , Gingiva/cytology , Humans , Imidazoles/pharmacology , Interferon-gamma/pharmacology , Interleukin-6/analysis , Interleukin-8/analysis , Interleukin-8/drug effects , JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors , Male , Middle Aged , Morpholines/pharmacology , Nod2 Signaling Adaptor Protein/analysis , Nod2 Signaling Adaptor Protein/drug effects , Periodontal Attachment Loss/pathology , Periodontal Pocket/pathology , Phosphoinositide-3 Kinase Inhibitors , Pyridines/pharmacology , Tumor Necrosis Factor-alpha/pharmacology
14.
J Dent Res ; 88(8): 762-7, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19734466

ABSTRACT

Pulp fibroblasts express various pro-inflammatory mediators leading to marked infiltration of inflammatory cells in the progression of pulpitis. We hypothesized that pulp fibroblasts play roles in the recognition of invaded caries-related bacteria and the subsequent innate immune responses. We found clear expressions of TLR2, NOD1, and NOD2 and a faint expression of TLR4 in human dental pulp fibroblasts (HDPF) by RT-PCR and flow cytometry. We also observed that various pro-inflammatory mediators, including cytokines, chemokines, adhesion molecules, prostaglandin E(2) and its key enzyme COX-2, not iNOS or caspase-1, were markedly up-regulated by stimulation with these TLR and NOD agonists. More over, the NOD2 agonist acted synergistically with the TLR2, not the TLR4, agonist to stimulate the production of pro-inflammatory mediators in HDPF. These findings indicate that TLR2, TLR4, NOD2, and NOD1 in HDPF are functional receptors, and NOD2 is a modulator of signals transmitted through TLR2 in pulpal immune responses, leading to progressive pulpitis.


Subject(s)
Apoptosis/immunology , Dental Pulp/immunology , Fibroblasts/immunology , Nod1 Signaling Adaptor Protein/analysis , Nod2 Signaling Adaptor Protein/analysis , Toll-Like Receptor 2/analysis , Toll-Like Receptor 4/analysis , Acetylmuramyl-Alanyl-Isoglutamine/pharmacology , Cells, Cultured , Chemokine CCL2/analysis , Chemokine CXCL10/analysis , Cyclooxygenase 2/immunology , Dental Pulp/cytology , Diaminopimelic Acid/analogs & derivatives , Dinoprostone/analysis , Escherichia coli , Humans , Inflammation Mediators/immunology , Interleukin-6/analysis , Interleukin-8/analysis , Lipopeptides/pharmacology , Lipopolysaccharides/pharmacology , Nod1 Signaling Adaptor Protein/antagonists & inhibitors , Nod2 Signaling Adaptor Protein/antagonists & inhibitors , Pulpitis/immunology , Signal Transduction/immunology , Streptococcus mutans/immunology , Toll-Like Receptor 2/antagonists & inhibitors , Toll-Like Receptor 4/antagonists & inhibitors , Vascular Cell Adhesion Molecule-1/analysis
15.
Oral Microbiol Immunol ; 23(4): 320-7, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18582332

ABSTRACT

INTRODUCTION: Pulpitis is characterized by the marked infiltration of inflammatory cells in response to an invasion of caries-related bacteria. It is well known that chemokines regulate the trafficking of lymphocytes, and CC chemokine ligand 20 (CCL20) has been recently shown to play a crucial role in the recruitment of memory T cells and immature dendritic cells into inflammatory lesions. We previously reported that CCL20 was mainly expressed in microvascular endothelial cells and macrophages that accumulated in inflamed pulp tissues and that its specific receptor, CCR6, was expressed on infiltrated lymphocytes. However, the mechanism of CCL20 expression remains unclear. METHODS AND RESULTS: In this study, we investigated the expression of CCL20 in monocytes/macrophages, endothelial cells, and pulpal fibroblasts after stimulation with Streptococcus mutans, a representative of caries-related bacteria, or proinflammatory cytokines. CCL20 messenger RNA was detected by reverse transcription-polymerase chain reaction in inflamed pulp, but not in clinically normal pulp. By enzyme-linked immunosorbent assay, S. mutans induced a human monocytic cell line, differentiated macrophage-like THP-1 cells, and human umbilical vein endothelial cells (HUVEC) to produce an increased amount of CCL20. Lipoteichoic acid from S. mutans also elicited CCL20 production by HUVEC. Moreover, CCL20 production from pulpal fibroblasts was increased by stimulation with inetrleukin-1beta and tumor necrosis factor-alpha. CONCLUSION: Our results indicate that CCL20 expression is induced by stimulation with caries-related bacteria that have invaded deeply into the dentinal tubules as well as by proinflammatory cytokines in the inflamed pulpal lesions. It may be involved in the progression of pulpitis via accumulation of inflammatory cells.


Subject(s)
Chemokine CCL20/immunology , Cytokines/immunology , Dental Pulp/immunology , Inflammation Mediators/immunology , Streptococcus mutans/immunology , Adult , Aged , Cell Differentiation/immunology , Cell Line , Cells, Cultured , Chemokine CCL20/genetics , Dental Pulp/microbiology , Endothelial Cells/immunology , Endothelium, Vascular/immunology , Female , Fibroblasts/immunology , Humans , Intercellular Adhesion Molecule-1/immunology , Interleukin-1beta/immunology , Interleukin-8/immunology , Lipopolysaccharides/immunology , Macrophages/immunology , Male , Middle Aged , Monocytes/immunology , Pulpitis/immunology , Teichoic Acids/immunology , Tumor Necrosis Factor-alpha/immunology , Vascular Cell Adhesion Molecule-1/immunology
16.
J Dent Res ; 86(12): 1217-22, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18037659

ABSTRACT

UNLABELLED: Marked infiltration of inflammatory cells, such as activated T-cells, is observed in the progression of pulpitis; however, little is known about the mechanism of their recruitment into pulpal lesions. It has been recently demonstrated that CXC chemokine ligand 10 (CXCL10) chemoattracts CXC chemokine receptor 3 (CXCR3)-positive activated T-cells. We therefore examined whether CXCL10 is involved in the pathogenesis of pulpitis. CXCL10 mRNA expression levels in clinically inflamed dental pulp were higher than those in healthy dental pulp. Immunostaining results revealed that CXCL10 was detected in macrophages, endothelial cells, and fibroblasts in inflamed dental pulp, and that CXCR3 expression was observed mainly on T-cells. Moreover, cultured dental pulp fibroblasts produced CXCL10 after stimulation with live caries-related bacteria, peptidoglycans, and pro-inflammatory cytokines. In contrast, heat-killed bacteria did not induce CXCL10 secretion. These findings suggest that CXCL10-CXCR3 may play an important role in the pulpal immune response to caries-related bacterial invasion. ABBREVIATIONS: CXCL10, CXC chemokine ligand 10; CXCR3, CXC chemokine receptor 3; IFN, interferon; FBS, fetal bovine serum; LTA, lipoteichoic acid; PGN, peptidoglycan; IL, interleukin; TNF, tumor necrosis factor; PBS, phosphate-buffered saline; ELISA, enzyme-linked immunosorbent assay; CCL, C-C chemokine ligand; TLR, Toll-like receptor; NOD, nucleotide oligomerization domain; HDPF, human dental pulp fibroblasts.


Subject(s)
Chemokine CXCL10/metabolism , Dental Caries/immunology , Dental Pulp/immunology , Receptors, CXCR3/metabolism , Adult , Bacteroides/immunology , Chemokine CXCL10/genetics , Dental Caries/microbiology , Dental Pulp/cytology , Dental Pulp/metabolism , Fibroblasts/metabolism , Humans , Immunohistochemistry , Lymphocyte Subsets/cytology , Lymphocyte Subsets/metabolism , Middle Aged , RNA, Messenger/analysis , Receptors, CXCR3/genetics
17.
Oral Microbiol Immunol ; 22(1): 36-45, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17241169

ABSTRACT

The periodontal vasculature is profoundly affected during the progression of periodontitis, and several specific bacteria are believed to be involved in this inflammatory disease. Eikenella corrodens is one of the common bacteria detected in periodontitis diseased lesions; however, the function of this organism in periodontitis is not well understood. In this study, we investigated the E. corrodens-induced endothelial cell alteration and inflammation process that leads to leukocyte infiltration in inflamed regions. Soluble products from E. corrodens (EcSP) induced the gene expression and protein production of vascular endothelial growth factor in oral epithelial cells and human umbilical vein endothelial cells (HUVEC). Direct stimulation by EcSP also activated endothelial cell proliferation. Moreover, EcSP induced ERK1/2 (p44/42) and p38 mitogen-activated protein kinase (MAPK) phosphorylation within 10-30 min in HUVEC, as demonstrated by Western blot analysis and up-regulated intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin and interleukin-8 (IL-8) production demonstrated by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. The specific p38 MAPK inhibitor SB203580 reduced the expression of ICAM-1, VCAM-1 and IL-8, whereas the blockade of p44/42 by MAPK kinase (MEK1) inhibitor, PD98059, inhibited only IL-8 expression. Our results indicate that E. corrodens can trigger a cascade of events that induce inflammatory responses in periodontal tissue via the MAPK cascade and may promote chronic periodontitis without bacteria-cell contact.


Subject(s)
Cell Adhesion Molecules/metabolism , Eikenella corrodens/physiology , Endothelial Cells/metabolism , Endothelium, Vascular/metabolism , Interleukin-8/metabolism , Mitogen-Activated Protein Kinases/metabolism , Cell Adhesion Molecules/analysis , Cell Line , Cell Proliferation/drug effects , Cells, Cultured , Culture Media, Conditioned/pharmacology , E-Selectin/analysis , E-Selectin/metabolism , Endothelium, Vascular/cytology , Enzyme Inhibitors/pharmacology , Epithelial Cells/metabolism , Flavonoids/pharmacology , Humans , Imidazoles/pharmacology , Intercellular Adhesion Molecule-1/analysis , Intercellular Adhesion Molecule-1/metabolism , Interleukin-8/analysis , Interleukin-8/antagonists & inhibitors , KB Cells , Mitogen-Activated Protein Kinase 1/analysis , Mitogen-Activated Protein Kinase 1/antagonists & inhibitors , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/analysis , Mitogen-Activated Protein Kinase 3/antagonists & inhibitors , Mitogen-Activated Protein Kinase 3/metabolism , Periodontitis/microbiology , Phosphorylation , Pyridines/pharmacology , Vascular Cell Adhesion Molecule-1/analysis , Vascular Cell Adhesion Molecule-1/metabolism , Vascular Endothelial Growth Factor A/analysis , Vascular Endothelial Growth Factor A/metabolism , p38 Mitogen-Activated Protein Kinases/analysis , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/metabolism
18.
J Dent Res ; 85(2): 106-21, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16434728

ABSTRACT

Periodontal diseases are a group of diseases that lead to erosion of the hard and soft tissues of the periodontium, which, in severe cases, can result in tooth loss. Anecdotal clinical observations have suggested that poor oral health may be associated with poor systemic health; however, only recently have appropriate epidemiological studies been initiated, with defined clinical endpoints of periodontal disease, to address the association of periodontal disease with increased risk for cardiovascular and cerebrovascular disease. Although conflicting reports exist, these epidemiological studies support this connection. Paralleling these epidemiological studies, emerging basic scientific studies also support that infection may represent a risk factor for atherosclerosis. With P. gingivalis as a model pathogen, in vitro studies support that this organism can activate host innate immune responses associated with atherosclerosis, and in vivo studies demonstrate that this organism can accelerate atheroma deposition in animal models. In this review, we focus primarily on the basic scientific studies performed to date which support that infection with bacteria, most notably P. gingivalis, accelerates atherosclerosis. Furthermore, we attempt to bring together these studies to provide an up-to-date framework of emerging theories into the mechanisms underlying periodontal disease and increased risk for atherosclerosis, as well as identify intervention strategies to reduce the incidence of periodontal disease in humans, in an attempt to decrease risk for systemic complications of periodontal disease such as atherosclerotic cardiovascular disease.


Subject(s)
Atherosclerosis/immunology , Atherosclerosis/microbiology , Immunity, Innate , Periodontal Diseases/immunology , Porphyromonas gingivalis/pathogenicity , Animals , Atherosclerosis/etiology , Disease Models, Animal , Endothelial Cells/immunology , Endothelial Cells/microbiology , Humans , Inflammation Mediators/physiology , Macrophages/immunology , Macrophages/microbiology , Mice , Periodontal Diseases/complications , Periodontal Diseases/microbiology , Porphyromonas gingivalis/immunology , Signal Transduction , Toll-Like Receptors/immunology
19.
Clin Exp Immunol ; 128(3): 548-54, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12067311

ABSTRACT

The regulatory role of chemokines and chemokine receptors on specific lymphocyte recruitment into periodontal diseased tissue is poorly characterized. We observed that lymphocytes infiltrating inflamed gingival tissue expressed marked levels of CCR6. In periodontal diseased tissue, the expression of MIP-3alpha mRNA was detected by RT-PCR and further, MIP-3alpha was distributed in the basal layer of gingival epithelial cells, microvascular endothelial cells and the areas of inflammatory cells as shown by immunohistochemistry. Moreover, CCR6-expressing cells infiltrated into periodontal diseased tissue, and the proportion of CCR6-positive CD4+ T cells was significantly elevated in periodontal diseased tissue compared with peripheral blood in the same patients. Furthermore, gingival lymphocytes isolated from patients showed migration toward MIP-3alpha in an in vitro chemotaxis assay in which migration was abrogated by specific antibody to CCR6. Thus, these findings suggested that CCR6 and the corresponding chemokine, MIP-3alpha may have an important regulatory role in specific lymphocyte migration into inflamed periodontal tissue.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Chemokines, CC/immunology , Gingiva/immunology , Macrophage Inflammatory Proteins/immunology , Periodontal Diseases/immunology , Receptors, Chemokine/immunology , Adult , Aged , Aged, 80 and over , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/physiology , Cells, Cultured , Chemokine CCL20 , Chemokines, CC/biosynthesis , Chemokines, CC/genetics , Chemokines, CC/pharmacology , Chemotaxis, Leukocyte/immunology , Female , Flow Cytometry/methods , Gene Expression , Gingiva/pathology , Humans , Macrophage Inflammatory Proteins/biosynthesis , Macrophage Inflammatory Proteins/genetics , Macrophage Inflammatory Proteins/pharmacology , Male , Middle Aged , Periodontal Diseases/pathology , Receptors, CCR6 , Receptors, Chemokine/biosynthesis
20.
Oral Microbiol Immunol ; 16(5): 296-305, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11555307

ABSTRACT

In the inflammatory response elicited by bacterial colonization in periodontal pockets, pocket epithelial cells not only serve as a barrier to isolate the pocket microenvironment from external stimuli but also regulate the functions of neighboring cells including fibroblasts and inflammatory cells. To elucidate this mechanism, we characterized the effects of periodontopathic bacterium Eikenella corrodens 1073 components on the production of some inflammatory mediators in a human oral epithelial cell line (KB). In enzyme-linked immunosorbent assay (ELISA), the E. corrodens supernatant induced interleukin-6 (IL-6), IL-8 and prostaglandin E2 but not interferon-gamma (IFN-gamma) production by KB cells. After incubation with E. corrodens supernatant, KB cells showed a marked increase in the levels of IL-6, IL-8 and PG G/H synthase (cyclooxygenase)-2, but not IFN-gamma, gene expression by reverse-transcriptase polymerase chain reaction. All these E. corrodens products responsible for production of these inflammatory mediators resisted freezing and boiling and were present in a 10-kDa filtrate. These results imply that these soluble small-molecular-mass products from E. corrodens stimulate various inflammatory mediator productions by human oral epithelial cells and may play a role in the initiation of periodontal inflammation and subsequently perpetuate the inflammatory response during chronic infection.


Subject(s)
Cytokines/biosynthesis , Eikenella corrodens/chemistry , Eikenella corrodens/pathogenicity , Inflammation Mediators/metabolism , Periodontal Diseases/microbiology , Bacterial Adhesion , Culture Media, Conditioned/pharmacology , Cyclooxygenase 2 , Dinoprostone/biosynthesis , Enzyme-Linked Immunosorbent Assay , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Epithelial Cells/microbiology , Gene Expression , Humans , Immunoblotting , Interleukin-6/biosynthesis , Interleukin-8/biosynthesis , Isoenzymes/biosynthesis , KB Cells/drug effects , KB Cells/metabolism , KB Cells/microbiology , Membrane Proteins , Periodontal Diseases/metabolism , Prostaglandin-Endoperoxide Synthases/biosynthesis , RNA, Messenger/analysis , Reverse Transcriptase Polymerase Chain Reaction , Up-Regulation
SELECTION OF CITATIONS
SEARCH DETAIL
...