• 한국콘텐츠학회논문지
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• 제21권4호
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• pp.825-832
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• 2021

본 연구는 치주질환의 주 원인균인 P. gingivalis에 선택적으로 작용하는 특이적 앱타머를 선별하고 선별된 앱타머와 결합하는 단백질 분자를 정제 및 동정함으로써 P. gingivalis에 관한 작용기전을 규명하고자 하였다. 이를 위하여 39개의 random sequence를 갖는 DNA library를 제조하여 SELEX 방법을 이용하여 P. gingivalis에 특이성을 가진 앱타머를 선별하였으며 PCR2.1 cloning vector를 활용한 cloning을 시행하여 염기서열을 분석했다. 8종의 각기 다른 염기서열을 가진 앱타머를 선별하였고 직접적으로 작용하는 단백질을 밝혀내고자 선별된 앱타머 중 APG-3를 이용하여 modified weston blot을 시행하고 단백질을 분석한 결과 P. gingivalis에 선택적으로 결합하는 11종의 단백질을 분리, 동정하였다. 이와 같은 결과로 앱타머가 치주질환의 원인균인 P. gingivalis의 당 대사 및 세포활성억제와 관련된 단백질에 선택적으로 결합하여 부착함으로써 치주질환의 진단을 위한 센서로 가능성을 제시했다.

• International Journal of Oral Biology
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• 제39권3호
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• pp.131-136
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• 2014

Porphyromonas gingivalis is one of the most important periodontal pathogens and has been to known to invade various types of cells, including endothelial cells. The present study investigated the mechanisms involved in the internalization of P. gingivalis in human umbilical vein endothelial cells (HUVEC). P. gingivalis internalization was reduced by clathrin and lipid raft inhibitors, as well as a siRNA knockdown of caveolin-1, a principal molecule of lipid raft-related caveolae. The internalization was also reduced by perturbation of actin rearrangement, while microtubule polymerization was not required. Furthermore, we found that Src kinases are critical for the internalization of P. gingivalis into HUVEC, while neither Rho family GTPases nor phosphatidylinositol 3-kinase are required. Taken together, this study indicated that P. gingivalis internalization into endothelial cells involves clathrin and lipid rafts and requires actin rearrangement associated with Src kinase activation.

• Journal of Periodontal and Implant Science
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• 제37권1호
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• pp.11-21
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• 2007

Heat shock protein (HSP) is one of cellular protein commonly present in major periodontopathogenic bacteria as well as mammalian cells. The protein may play a role in the immunopathogenesis by modulating autoimmune reaction due to its high level of sequence homology between bacteria and human counterpart. Hence, identifying immunodomiant epitope of bacteria HSP that is cross-reactive to periodontopathogenic bacteria with a specificity to human HSP may comprise a critical strategy for development of a periodontal vaccine. The present study was performed to establish clones producing monoclonal antibody reactive to Porphyromonas gingivalis (p. gingivalis) HSP with a specificity to human HSP. 4 different hybridomas were cloned producing monoclonal IgG antibodies to P, gingivalis HSP and evaluated for their reactivity and specificity to other periodontopathogenic bacteria as well as to human HSP. These four monoclonal antibodies reacted with p. gingivalis HSP only with specificities to other bacteria tested and human HSP as well. The antigenic epitopes producing the 4 monoclonal antibody may be potentially developed as vaccine candidates. Further investigations are under way to identify more clones producing monoclonal antibodies reactive to P, gingivalis HSP and to other periodontopathogenic bacteria as well, while maintaining specificities to human counterpart.

• International Journal of Oral Biology
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• 제33권4호
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• pp.149-154
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• 2008

Porphyromonas gingivalis, a major periodontal pathogen, has been implicated in the initiation and progression of periodontal disease. Endothelial dysfunction (Editor note: Aberrant and dysfunction are somewhat redundant. The authors may want to choose one or the other.) contributes to chronic periodontal inflammation. Using cDNA-representational difference analysis, we found that P.gingivalis lipopolysaccharide differentially induces a number of genes in human microvascular endothelial cells. Among these upregulated genes, we focused on intercellular adhesion molecule-1 (VCAM-1), which is crucial for leukocyte recruitment during vascular inflammation. P. gingivalis LPS significantly increased the expression of vascular cell adhesion molecule-1 (VCAM-1) as well as ICAM-1. Promoter assays revealed that the transcription of these cell adhesion molecules was mainly regulated by nuclear factor-${\kappa}B$ (NF-${\kappa}B$) in endothelial cells. Furthermore, P. gingivalis LPS significantly increased leukocyte adhesiveness to microvascular endothelial cells and to aortic endothelium. Taken together, our results demonstrate that P. gingivalis LPS activates microvascular endothelial cells through NF-${\kappa}B$-dependent expression of cell adhesion molecules.

• International Journal of Oral Biology
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• 제44권1호
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• pp.20-26
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• 2019

Periodontal diseases have been associated with the development of cardiovascular diseases. Accumulating evidences have indicated that Porphyromonas gingivalis, a major periodontopathic pathogen, plays a critical role in the pathogenesis of atherosclerosis. In the present study, we demonstrated that P. gingivalis lipopolysaccharide (LPS) increases the mRNA and protein expression of matrix metalloproteinase-9 (MMP-9) in rat vascular smooth muscle cells. We showed that the MMP-9 expression induced by P. gingivalis LPS is mediated by the activation of signal transducer and activator of transcription 3 (STAT3) in vascular smooth muscle cells. Furthermore, the inhibition of STAT3 activity reduced P. gingivalis LPS-induced migration of vascular smooth muscle cells. Overall, our findings indicate that P. gingivalis LPS stimulates the migration of vascular smooth muscle cells via STAT3-mediated MMP-9 expression.

• Journal of Periodontal and Implant Science
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• 제36권1호
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• pp.265-272
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• 2006

Dental plaque, a biofilm consisting of more than 500 different bacterial species, is an etiological agent of human periodontal disease, It is therefore important to characterize interactions among periodontopathic microorganisms in order to understand the microbial pathogenesis of periodontal disease. Previous data have suggested a synergistic effect of tow major periodontal pathogens Porphyromonas gingivalis and Tannerella forsythia in the periodontal lesion. In the present study, to better understand interaction between P. gingivalis and T. forsythia, the coaggregation activity between these bacteria was characterized. The coaggregation activity was observed by a direct visual assay by mixing equal amount (1 ${\times}$ $10^9$)of T. forsythia and P. gingivaJis cells. It was found that the first aggregates began to appear after 5-10 min, and that the large aggregates completely settled within 1 h. Electron and epifluorescence microscopic studies confirmed cell-cell contact between two bacteria. The heat treatment of P. gingivalis completely blocked the activity, suggesting an involvement of a heat-labile component of P. gingivalis in the interaction. On the other hand, heat treatment of T. forsythia significantly increased the coaggregation activity; the aggregates began to appear immediately. The coaggregation activity was inhibited by addition of protease, however carbohydrates did not inhibit the activity, suggesting that coaggregation is a protein-protein interaction. The results of this study suggest that coaggregation between P. gingivalis and T. forsythia is a result of cell-cell physical contact, and that coaggregation is mediated by a heat-labile component of P. gingivalis and T. forsythia component that can be activated on heat treatment.

• Journal of Periodontal and Implant Science
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• 제35권4호
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• pp.907-919
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• 2005

Porphyromonas gingivalis is a gram negative. black-pigmented anaerobe, associated with periodontitis & peri-implantitis. Fimbriae(fimA) of P. gingivalis are filamentous components on the cell surface and important in the colonization and invasion of periodontal tissue. But all P. gnigivalis strains don't have equal pathogenicity, inequality among strains originates from different fimA genotype. P. gnigivalis fimA gene encoding fimbrillin(structural subunit of fimbriae) has been classified into 5 genotypes(types I to V) based on the nucleotide sequences. In the present study, we examined the prevalence of these fimA genotypes in patients with dental implant and the relationship between prevalence of these genotypes and a condition of peri-implant tissue. Dental plaque specimens obtained from 189 peri-implant sulci of 97 patients with dental implants were analyzed by 16S rRNA fimA gene-directed PCR assay. P. gingivalis were detected in 86.2% of the alll samples. Among the P. gingivalis-positive samples, a significant difference in the occurrence of typeII was observed between test and the two control groups. In two control groups, typeII fimA were detected in 6.3%(PD<5mm/BOP-). 18.7%(PD<5mm/BOP+). In the test $group(PD{\geqq}5mm/BOP+)$, type II fimA genotype were detected most frequently in 50.0% . And a correlation between specific fimA types and peri-implantitis was found in $typeII(R^2=l.105)$. These results suggest that P. gingivalis strains that possess typeII fimA are gradually increased, as a condition of peri-implant tissue is getting complicated and are closely associated with peri-implant health status. We speculate that these organisms be involved in peri-implantitis

• BMB Reports
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• 제54권6호
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• pp.323-328
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• 2021

Periodontal diseases have been reported to have a multidirectional association with metabolic disorders. We sought to investigate the correlation between periodontitis and diabetes or fatty liver disease using HFD-fed obese mice inoculated with P. gingivalis. Body weight, alveolar bone loss, serological biochemistry, and glucose level were determined to evaluate the pathophysiology of periodontitis and diabetes. For the evaluation of fatty liver disease, hepatic nonalcoholic steatohepatitis (NASH) was assessed by scoring steatosis, inflammation, hepatocyte ballooning and the crucial signaling pathways involved in liver metabolism were analyzed. The C-reactive protein (CRP) level and NASH score in P. gingivalis-infected obese mice were significantly elevated. Particularly, the extensive lobular inflammation was observed in the liver of obese mice infected with P. gingivalis. Moreover, the expression of metabolic regulatory factors, including peroxisome proliferator-activated receptor γ (Pparγ) and the fatty acid transporter Cd36, was up-regulated in the liver of P. gingivalis-infected obese mice. However, inoculation of P. gingivalis had no significant influence on glucose homeostasis, insulin resistance, and hepatic mTOR/AMPK signaling. In conclusion, our results indicate that P. gingivalis can induce the progression of fatty liver disease in HFD-fed mice through the upregulation of CD36-PPARγ axis.

• Journal of Periodontal and Implant Science
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• 제35권4호
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• pp.1081-1095
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• 2005

본 연구는 치주질환 주요 병인균주 중의 하나인 Porphyromonas gingivalis의 세균내독소가 마우스 대식 세포주인 RAW264.7 세포에서의 nitric oxide의 생성과 iNOS의 발현에 미치는 영향을 분석하고 그 기전을 규명하기 위해 수행되었다. Butanol추출법과 phenol-water법에 의해 P. gingivalis 381로부터 세균내독소를 추출하였으며, NO의 생성은 배양 상층액 내의 nitrite 농도를 측정하여 결정하였다. 또한, iNOS의 western blot 분석과 reverse transcription (RT)-PCR 산물의 분석을 수행하였다. P. gingivalis의 세균내독소는 부가적인 자극이 없는 상태에서도 iNOS의 발현과 NO 생성을 유발하였으며, NF- ${\kappa}B$, microtubule polymerization, protein tyrosine kinase, 그리고 protein kinase C 등이 P. gingivalis 세균내독소에 의한 NO 생성에 간여하는 것으로 여겨진다. 또한, P. gingivalis 세균내독소에 의한 NO 생성에는 L-arginine이 요구되었다. P. gingivalis 세균내독소에 의한 NO 생성은 염증성 치주질환의 발병과 진행에 있어 중요한 역할을 하는 것으로 여겨진다.

• Journal of Korean Academy of Oral Health
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• 제41권1호
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• pp.22-27
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• 2017

Objectives: Dental plaque is composed of 700 bacterial species. It is known that some oral microorganisms produce porphyrin, and thus, they emit red fluorescence when illuminated with blue light at a specific wavelength of <410 nm. Porphyromonas gingivalis belongs to the genus Porphyromonas, which is characterized by the production of porphyrin. The aim of this study was to evaluate red fluorescence emission of some oral microorganisms interacting with P. gingivalis. Methods: Five bacterial strains (P. gingivalis, Streptococcus mutans, Lactobacillus casei, Actinomyces naeslundii, and Fusobacterium nucleatum) were used for this study. Tryptic soy agar medium supplemented with hemin, vitamin K3, and sheep blood was used as a growth medium. The fluorescence emission of bacterial colonies was evaluated under 405 nm-wavelength blue light using a Quantitative Light-induced Fluorescence Digital (QLF-D) camera system. Each bacterium was cultured alone and co-cultured in close proximity with P. gingivalis. The red/green (R/G) ratio of fluorescence image was calculated and the differences of R/G ratio according to each growth condition were compared using the Mann-Whitney test (P<0.05). Results: Single cultured S. mutans, L. casei and A. naeslundii colonies emitted red fluorescence (R/G ratio=$2.15{\pm}0.06$, $4.31{\pm}0.17$, $5.52{\pm}1.29$, respectively). Fusobacterium nucleatum colonies emitted green fluorescence (R/G ratio=$1.36{\pm}0.06$). The R/G ratios of A. naeslundii and F. nucleatum were increased when P. gingivalis was co-cultured with each bacterium (P<0.05). In contrast, the R/G ratios of S. mutans and L. casei were decreased when P. gingivalis was co-cultured with each bacterium (P=0.002, 0.003). Conclusions: This study confirmed that P. gingivalis could affect the red fluorescence of other oral bacteria under 405 nm-wavelength blue light. Our findings concluded that P. gingivalis has an important role for red fluorescence emission of dental biofilm.