scholarly journals Structural Dissection andIn VivoEffectiveness of a Peptide Inhibitor ofPorphyromonas gingivalisAdherence toStreptococcus gordonii

2010 ◽  
Vol 79 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Carlo Amorin Daep ◽  
Elizabeth A. Novak ◽  
Richard J. Lamont ◽  
Donald R. Demuth

ABSTRACTThe interaction of the minor fimbrial antigen (Mfa) with streptococcal antigen I/II (e.g., SspB) facilitates colonization of the dental biofilm byPorphyromonas gingivalis.We previously showed that a 27-mer peptide derived from SspB (designated BAR) resembles the nuclear receptor (NR) box protein-protein interacting domain and potently inhibits this interactionin vitro. Here, we show that the EXXP motif upstream of the NR core α-helix contributes to the Mfa-SspB interaction and that BAR reducesP. gingivaliscolonization and alveolar bone lossin vivoin a murine model of periodontitis. Substitution of Gln for Pro1171or Glu1168increased the α-helicity of BAR and reduced its inhibitory activityin vitroby 10-fold and 2-fold, respectively. To determine if BAR preventsP. gingivalisinfectionin vivo, mice were first infected withStreptococcus gordoniiand then challenged withP. gingivalisin the absence and presence of BAR. Animals that were infected with either 109CFU ofS. gordoniiDL-1 or 107CFU ofP. gingivalis33277 did not show a statistically significant increase in alveolar bone resorption over sham-infected controls. However, infection with 109CFU ofS. gordoniifollowed by 107CFU ofP. gingivalisinduced significantly greater bone loss (P< 0.01) than sham infection or infection of mice with either organism alone.S. gordonii-infected mice that were subsequently challenged with 107CFU ofP. gingivalisin the presence of BAR exhibited levels of bone resorption similar to those of sham-infected animals. Together, these results indicate that both EXXP and the NR box are important for the Mfa-SspB interaction and that BAR peptide represents a potential therapeutic that may limit colonization of the oral cavity byP. gingivalis.

Medicina ◽  
2021 ◽  
Vol 57 (10) ◽  
pp. 1054
Author(s):  
Seong-Hee Moon ◽  
Seong-Jin Shin ◽  
Hyun-Jin Tae ◽  
Seung-Han Oh ◽  
Ji-Myung Bae

Background and Objectives: Periodontal disease is a chronic inflammatory disease in which gradual destruction of tissues around teeth is caused by plaque formed by pathogenic bacteria. The purpose of this study was to evaluate the potential of 75% ethanol extract of Colocasia antiquorum var. esculenta (CA) as a prophylactic and improvement agent for periodontal disease in vitro and in vivo. Materials and Methods: The antimicrobial efficacy of CA against Porphyromonas gingivalis (P. gingivalis, ATCC 33277) was evaluated using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) test, and cytotoxicity was confirmed by CCK-8 assay. For the in vivo study, P. gingivalis was applied by oral gavage to BALB/c mice. Forty-two days after the first inoculation of P. gingivalis, intraoral swabs were taken for microbiome analysis, and the mice were sacrificed to evaluate the alveolar bone loss. Results: The MIC of CA against P. gingivalis was 31.3 μg/mL, the MBC was 62.5 μg/mL, with no cytotoxicity. The diversity of the oral microbiome decreased in the positive control group, while those of the VA (varnish) and VCA (varnish added with CA) groups increased as much as in the negative control group, although the alveolar bone loss was not induced in the mouse model. Conclusions: CA showed antibacterial effects in vitro, and the VA and VCA groups exhibited increased diversity in the oral microbiome, suggesting that CA has potential for improving periodontal disease.


Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 619
Author(s):  
Hyun-Jung Park ◽  
Malihatosadat Gholam-Zadeh ◽  
Sun-Young Yoon ◽  
Jae-Hee Suh ◽  
Hye-Seon Choi

Loss of ovarian function is closely related to estrogen (E2) deficiency, which is responsible for increased osteoclast (OC) differentiation and activity. We aimed to investigate the action mechanism of E2 to decrease bone resorption in OCs to protect from ovariectomy (OVX)-induced bone loss in mice. In vivo, tartrate-resistant acid phosphatase (TRAP) staining in femur and serum carboxy-terminal collagen crosslinks-1 (CTX-1) were analyzed upon E2 injection after OVX in mice. In vitro, OCs were analyzed by TRAP staining, actin ring formation, carboxymethylation, determination of reactive oxygen species (ROS) level, and immunoprecipitation coupled with Western blot. In vivo and in vitro, E2 decreased OC size more dramatically than OC number and Methyl-piperidino-pyrazole hydrate dihydrochloride (MPPD), an estrogen receptor alpha (ERα) antagonist, augmented the OC size. ERα was found in plasma membranes and E2/ERα signaling affected receptor activator of nuclear factor κB ligand (RANKL)-induced actin ring formation by rapidly decreasing a proto-oncogene tyrosine-protein kinase, cellular sarcoma (c-Src) (Y416) phosphorylation in OCs. E2 exposure decreased physical interactions between NADPH oxidase 1 (NOX1) and the oxidized form of c-Src homology 2 (SH2)-containing protein tyrosine phosphatase 2 (SHP2), leading to higher levels of reduced SHP2. ERα formed a complex with the reduced form of SHP2 and c-Src to decrease c-Src activation upon E2 exposure, which blocked a signal for actin ring formation by decreased Vav guanine nucleotide exchange factor 3 (Vav3) (p–Y) and Ras-related C3 botulinum toxin substrate 1 (Rac1) (GTP) activation in OCs. E2/ERα signals consistently inhibited bone resorption in vitro. In conclusion, our study suggests that E2-binding to ERα forms a complex with SHP2/c-Src to attenuate c-Src activation that was induced upon RANKL stimulation in a non-genomic manner, resulting in an impaired actin ring formation and reducing bone resorption.


2017 ◽  
Vol 233 (1) ◽  
pp. 476-485 ◽  
Author(s):  
Cheng-Ming Wei ◽  
Qian Liu ◽  
Fang-Ming Song ◽  
Xi-Xi Lin ◽  
Yi-Ji Su ◽  
...  
Keyword(s):  

2020 ◽  
Vol Volume 14 ◽  
pp. 4189-4203
Author(s):  
Peng Sun ◽  
Qichang Yang ◽  
Yanben Wang ◽  
Jiaxuan Peng ◽  
Kangxian Zhao ◽  
...  

2003 ◽  
Vol 47 (3) ◽  
pp. 932-940 ◽  
Author(s):  
N. Kömerik ◽  
H. Nakanishi ◽  
A. J. MacRobert ◽  
B. Henderson ◽  
P. Speight ◽  
...  

ABSTRACT Porphyromonas gingivalis is one of the major causative organisms of periodontitis and has been shown to be susceptible to toluidine blue-mediated photosensitization in vitro. The aims of the present study were to determine whether this technique could be used to kill the organism in the oral cavities of rats and whether this would result in a reduction in the alveolar bone loss characteristic of periodontitis. The maxillary molars of rats were inoculated with P. gingivalis and exposed to up to 48 J of 630-nm laser light in the presence of toluidine blue. The number of surviving bacteria was then determined, and the periodontal structures were examined for evidence of any damage. When toluidine blue was used together with laser light there was a significant reduction in the number of viable P. gingivalis organisms. No viable bacteria could be detected when 1 mg of toluidine blue per ml was used in conjunction with all light doses used. On histological examination, no adverse effect of photosensitization on the adjacent tissues was observed. In a further group of animals, after time was allowed for the disease to develop in controls, the rats were killed and the level of maxillary molar alveolar bone was assessed. The bone loss in the animals treated with light and toluidine blue was found to be significantly less than that in the control groups. The results of this study show that toluidine blue-mediated lethal photosensitization of P. gingivalis is possible in vivo and that this results in decreased bone loss. These findings suggest that photodynamic therapy may be useful as an alternative approach for the antimicrobial treatment of periodontitis.


2020 ◽  
Vol 75 ◽  
pp. 104226
Author(s):  
Juliana Simeão Borges ◽  
Luiz Renato Paranhos ◽  
Gabriela Leite de Souza ◽  
Felipe de Souza Matos ◽  
Ítalo de Macedo Bernardino ◽  
...  

2010 ◽  
Vol 89 (2) ◽  
pp. 192-197 ◽  
Author(s):  
T. Ohnishi ◽  
A. Okamoto ◽  
K. Kakimoto ◽  
K. Bandow ◽  
N. Chiba ◽  
...  

Periodontitis causes resorption of alveolar bone, in which RANKL induces osteoclastogenesis. The binding of lipopolysaccharide to Toll-like receptors causes phosphorylation of Cot/Tp12 to activate the MAPK cascade. Previous in vitro studies showed that Cot/Tp12 was essential for the induction of RANKL expression by lipopolysaccharide. In this study, we examined whether Cot/Tp12 deficiency reduced the progression of alveolar bone loss and osteoclastogenesis during experimental periodontitis. We found that the extent of alveolar bone loss and osteoclastogenesis induced by ligature-induced periodontitis was decreased in Cot/Tp12-deficient mice. In addition, reduction of RANKL expression was observed in periodontal tissues of Cot/Tp12-deficient mice with experimental periodontitis. Furthermore, we found that Cot/Tp12 was involved in the induction of TNF-α mRNA expression in gingiva of mice with experimental periodontitis. Our observations suggested that Cot/Tp12 is essential for the progression of alveolar bone loss and osteoclastogenesis in periodontal tissue during experimental periodontitis mediated through increased RANKL expression.


2010 ◽  
Vol 78 (7) ◽  
pp. 2919-2926 ◽  
Author(s):  
Elizabeth A. Novak ◽  
HanJuan Shao ◽  
Carlo Amorin Daep ◽  
Donald R. Demuth

ABSTRACT Biofilm formation by the periodontal pathogen Aggregatibacter actinomycetemcomitans is dependent upon autoinducer-2 (AI-2)-mediated quorum sensing. However, the components that link the detection of the AI-2 signal to downstream gene expression have not been determined. One potential regulator is the QseBC two-component system, which is part of the AI-2-dependent response pathway that controls biofilm formation in Escherichia coli. Here we show that the expression of QseBC in A. actinomycetemcomitans is induced by AI-2 and that induction requires the AI-2 receptors, LsrB and/or RbsB. Additionally, inactivation of qseC resulted in reduced biofilm growth. Since the ability to grow in biofilms is essential for A. actinomycetemcomitans virulence, strains that were deficient in QseC or the AI-2 receptors were examined in an in vivo mouse model of periodontitis. The ΔqseC mutant induced significantly less alveolar bone resorption than the wild-type strain (P < 0.02). Bone loss in animals infected with the ΔqseC strain was similar to that in sham-infected animals. The ΔlsrB, ΔrbsB, and ΔlsrB ΔrbsB strains also induced significantly less alveolar bone resorption than the wild type (P < 0.03, P < 0.02, and P < 0.01, respectively). However, bone loss induced by a ΔluxS strain was indistinguishable from that induced by the wild type, suggesting that AI-2 produced by indigenous microflora in the murine oral cavity may complement the ΔluxS mutation. Together, these results suggest that the QseBC two-component system is part of the AI-2 regulon and may link the detection of AI-2 to the regulation of downstream cellular processes that are involved in biofilm formation and virulence of A. actinomycetemcomitans.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Piero Ruscitti ◽  
Paola Cipriani ◽  
Francesco Carubbi ◽  
Vasiliki Liakouli ◽  
Francesca Zazzeroni ◽  
...  

Several inflammatory diseases have been associated with increased bone resorption and fracture rates and different studies supported the relation between inflammatory cytokines and osteoclast activity. The main factor required for osteoclast activation is the stimulation by receptor activator of nuclear factor kappa-B ligand (RANKL) expressed on osteoblasts. In this context, interleukin- (IL-) 1β, one of the most powerful proinflammatory cytokines, is a strong stimulator of in vitro and in vivo bone resorption via upregulation of RANKL that stimulates the osteoclastogenesis. The resulting effects lead to an imbalance in bone metabolism favouring bone resorption and osteoporosis. In this paper, we review the available literature on the role of IL-1βin the pathogenesis of bone loss. Furthermore, we analysed the role of IL-1βin bone resorption during rheumatic diseases and, when available, we reported the efficacy of anti-IL-1βtherapy in this field.


2001 ◽  
Vol 44 (9) ◽  
pp. 2185-2192 ◽  
Author(s):  
Kenneth J. Armour ◽  
Robert J. Van 't Hof ◽  
Katharine E. Armour ◽  
Anne C. Torbergsen ◽  
Piero Del Soldato ◽  
...  
Keyword(s):  

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