• Journal of dental hygiene science
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• v.23 no.2
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• pp.169-175
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• 2023

Background: Although microbial infection is direct cause of periodontal disease, various environmental factors influence the disease severity. Aging is considered a risk factor for oral diseases, with the prevalence of periodontal diseases increasing with age. Moreover, senescence-associated secretory phenotype (SASP) expressed in age-related diseases is a key marker of chronic inflammation and aging phenotypes. Therefore, this study aimed to understand the relevance of senescent cells to periodontal health and disease, investigate the possibility of regulating the expression of aging- and osteolysis-related factors in gingival fibroblasts, and investigate the effect of senescence induction in gingival fibroblasts on osteoclast differentiation in mouse bone marrow-derived macrophages (BMMs). Methods: After stimulation with 400 nM hydrogen peroxidase, human gingival fibroblasts (HGFs) were examined for senescence-associated β-galactosidase. Western blot and enzyme-linked immunosorbent assays were performed to assess the expression of SASP. Osteoclast formation was assessed in BMMs using a conditioned medium (CM) from hydrogen peroxide-stimulated HGFs. Osteoclastic differentiation was investigated using tartrate-resistant acid phosphatase (TRAP) staining and activity. Data analysis was performed using SPSS version 25.0. Results: The expression of senescence-related molecules, including p53, p16, and p21, and the expression of osteolytic factors, including IL-6, IL-8, and IL-17, were found to be significantly higher in the hydrogen peroxide-stimulated HGF than in the control group. Regarding the indirect effects of senescent gingival cells, the number of osteoclasts and TRAP activity increased according to the differentiation of BMM cultured in CM. Conclusion: Our results on the of between osteolytic factors and cellular senescence in gingival fibroblast cells helped to reveal evidence of pathological aging mechanisms. Furthermore, our results suggest that the development of novel therapies that target specific SASP factors could be an effective treatment strategy for periodontal disease.

• Journal of Periodontal and Implant Science
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• v.23 no.2
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• pp.228-242
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• 1993

Some therapeutic agents and medicaments may lead to pathologic changes in the gingival tissue, especially on the cultured human gingival fibroblasts. The purpose of this study was to investigate on the effect of diphenylhydantoin, retinoic acid to the human gingival fibroblast. Human gingival fibroblasts were cultured from the healthy gingiva of patients with orthodontic patients. Gingival fibroblasts were trypsinized and transferred to the wells of 96 well microtest plates. Next day, the medium was removed, fibroblasts were washed with HBSS, and the washed cells were cultured in growth medium added 5 or $10{\mu}g/ml$ of diphenylhydantoin, $10^{-5}M$, $10^{-6}M$ and $10^{-7}M$ of retinoic acid and glycyrrhetinic acid. The passage number of cultured fibroblasts were fifth and eighth. The cell morphology was examined by inverted microscope, the cell number was counted by hemocytometer, and cell activity was measured by the growth and proliferatiton assay using MTT assay. The fifth experiments were performed and statistical significance was measured by ANOVA. The cell morphology in the presence of retinoic acid was round irrespective of the presence of diphenylhydantoin and glycyrrhetinic acid(Fig 2-6). The proliferation of cells was not changed by diphenylhydantoin(Table 1). The cell activity showed the tendency to increase at the concentration of $10{\mu}$'/, of diphenylhydantoin (Table 2). The cell activity in the presence of retinoic acid glycyrrhetinic acid was decreased, and the increased cell activity by diphenylhydantoin was decreased by retinoic acid and glycyrrhetinic acid at the concentration of $10^{-7}M$(Table 3-5). These results suggested that the increased cell activity by diphenylhydantoin might be modulated by retinoic acid and glycyrrhetinic acid.

• Journal of Periodontal and Implant Science
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• v.54 no.4
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• pp.236-252
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• 2024

Purpose: Enamel matrix derivative (EMD) has demonstrated beneficial effects on wound healing following surgery. However, the effects of recombinant human fibroblast growth factor 2 (rhFGF-2) in periodontal regeneration therapy have not been extensively studied. This retrospective study was conducted to compare the wound healing outcomes of the modified papilla preservation technique (mPPT) between EMD and rhFGF-2 therapies. Methods: A total of 79 sites were evaluated for early wound healing using the modified early wound healing index (mEHI), which included 6 items: incision, fibrin clotting, step, redness, swelling, and dehiscence. A numeric analog scale, along with postoperative images of the 6 mEHI items, was established and used for the evaluations. The inter-rater reliability of the mEHI was assessed via intraclass correlation coefficients (ICCs). After adjusting for factors influencing the mPPT, the differences in mEHI scores between the EMD and rhFGF-2 groups were statistically analyzed. Additionally, radiographic bone fill (RBF) was evaluated 6 months after surgery. Results: The ICC of the mEHI was 0.575. The mEHI, redness score, and dehiscence scores were significantly higher in the rhFGF-2 group (n=33) than in the EMD group (n=46). Similar results were observed in the subgroup of patients aged 50 years or older, but not in those younger than 50 years. In the subgroup with non-contained bone defects, related results were noted, but not in the subgroup with contained bone defects. However, early wound healing did not correlate with RBF at 6 months after surgery. Conclusions: Within the limitations of this study, the findings suggest that early wound healing following the use of mPPT with rhFGF-2 is somewhat superior to that observed after mPPT with EMD. However, mEHI should be improved for use as a predictive tool for early wound healing and to reflect clinical outcomes after surgery.

• Restorative Dentistry and Endodontics
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• v.24 no.1
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• pp.76-87
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• 1999

The effect of retrograde root-end filling materials(IRM, Super-EBA, Vitremer, MTA) on human periodontal ligament fibroblasts and osteoblasts was observed. The cell activities were evaluated by MTT assay, protein assay and alkaline phosphatase activity examination. The results as follows ; 1. After 24hrs culture, both E1 cells & PDL fibroblast adding root-end filling materials were suppressed cell activities but after 48hrs, cell activities were recovered. 2. Cell activity was lowest in Vitremer followed by IRM, MTA, Super-EBA. 3. Cell activity depression by Vitremer was not concerned with pH changes. 4. Protein synthesis by root-end filling materials were not significant difference in Both E1 cell & PDL fibroblasts but protein synthesis were a little increased by Super-EBA. 5. Alkaline phosphatase activity was increased in E1 cell by Super-EBA & MTA but was not significant differences in E1 cell by IRM & Vitremer. Alkaline phosphatase activity was a little depressed in PDL fibroblast by Vitremer. This findings suggest that these root-end filling materials may have important roles in promotion of PDL healing and consequently may be useful for clinical application in apical surgery.

• Journal of Periodontal and Implant Science
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• v.31 no.4
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• pp.833-846
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• 2001

Recently, use of natural medicine is getting more attention, and some of them are believed to be effective in　the treatment of periodontitis. Among them, the seeds of safflower(Carthamus tinctrorius L.) have been proven to be effective through its use in bone diseases such as fracture and osteoporosis. During the last few years, studies using the seeds of safflower gown in Korea have been active, and it has been reported that safflower seed extract increase the proliferation and the alkaline phosphatase(ALP) activity of human periodontal ligament fibroblast(hPDLF), osteoblast, and that they promote the mineralization process. In animal studies, when safflower seed extract were administered orally new bone formation was promoted. Recently, in an effort to find out the most effective osteogenic components, among many components of the safflower seed, various safflower seed fraction extracts were obtained by multistep extraction of the safflower components using various solvents. Among these, saf-M-W fraction extracted by methanol and water was most effective in increasing osteogenic potential of osteoblasts. In this study, the effect of safflower seed fraction extract, saf-M-W, on the growth and differentiation of hPDLF and MC3T3-E1 cell was investigated. The toxicity of saf-M-W on both cells was measured using M'IT(3-(4,5dimethylthiazol-2-y1)-2,5-diphenyl tetrazolium bromide) test, and ALP activity was measured using the colorimetric assay of hPDLF. In addition, in MC3T3-El cells, the expression of ALP, bone sialoprotein(BSP) mRNA was observed using Northern blot, and the mineralized nodule formation Was observed using von Kossa stain and phase-contrast microscope. 1. In concentrations below $10{\mu}g/ml$, saf-M-W didn't show any toxicity on hPDLF and MC3T3-El cell. 2. The change in saf-M-W concentration had no effect on the ALP activity of hPDLF. 3. In MC3T-E1 cells, mRNA expressions of ALP and BSP were greater in the experimental group treated with $10{\mu}g/ml$ concentration of saf-M-W compared with the control group. 4. In MC3T3-El cells, abundance of mineralized nodules were formed in the experimental group treated with $10{\mu}g/ml$ Concentration of saf-M-W, while no mineralized nodule was formed in the control group. These results suggest that safflower seed fraction extract, saf-M-W. didn't show any toxicity on hPDLF and MC3T3-E1 cell at concentrations below $10{\mu}g/ml$ and effectively enhanced the differentiation and osteogenic potential of MC3T3-El cell.

• Journal of Oral Medicine and Pain
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• v.24 no.4
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• pp.361-374
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• 1999

F. nucleatum is a gram-negative obligate anaerobe which is the principal and most frequent cause of gingival inflammation and is the predominant pathogen isolated in subsequent periodontal breakdown. It is also one of the most numerous bacteria found in subgingival plaque samples from healthy sites; its numbers are about 10-fold greater in plaque from periodontally diseased sites. The purpose of this study is to examine the effects of outer membrane(OM), outer membrane vesicle(OMV), and lipopolysaccharide(LPS) from F. nucleatum ATCC 25586 strain on the growth of human gingival fibroblasts and HOS 941 cells, and on the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression of mouse splenocytes. For the examination of cytotoxic effects, $TNF-{\alpha}$ production and $TNF-{\alpha}$ mRNA expression, the MTT assay, the ELISA and the RT-PCR were performed, respectively. All extracts of F. nucleatum tested were cytotoxic to both of human gingival fibroblasts and HOS 941 cells, and the significant difference of cytotoxic activity among the extracts was not observed. In the effects of these extracts on the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression of mouse splenocytes, all extracts of F. nucleatum tested also stimulated the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression, but the effects of the OM extracts on the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression were higher than those of the OMV and the LPS extracts. The pattern of the $TNF-{\alpha}$ mRNA expression was similar to that of the $TNF-{\alpha}$ production. These results indicate that F. nucleatum seems to contribute to the pathogenesis of periodontal diseases at least by its cytotoxicity, directly and its $TNF-{\alpha}$ production, indirectly.

• Journal of Periodontal and Implant Science
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• v.41 no.1
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• pp.17-22
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• 2011

Purpose: Nitric oxide (NO) has been known as an important regulator of osteoblasts and periodontal ligament cell activity. This study was performed to investigate the relationship between NO-mediated cell death of human periodontal ligament fibroblasts (PDLFs) and N-methyl-D-aspartic acid (NMDA) receptor antagonist (+)-5-methyl-10, 11-dihydro-5H-dibenzo[a,d]cyclohepten-5, 10-imine hydrogen maleate (MK801). Methods: Human PDLFs were treated with various concentrations (0 to 4 mM) of sodium nitroprusside (SNP) with or without $200\;{\mu}M$ MK801 in culture media for 16 hours and the cell medium was then removed and replaced by fresh medium containing MTS reagent for cell proliferation assay. Western blot analysis was performed to investigate the effects of SNP on the expression of Bax, cytochrome c, and caspase-3 proteins. The differences for each value among the sample groups were compared using analysis of variance with 95% confidence intervals. Results: In the case of SNP treatment, as a NO donor, cell viability was significantly decreased in a concentration-dependent manner. In addition, a synergistic effect was shown when both SNP and NMDA receptor antagonist was added to the medium. SNP treated PDLFs exhibited a round shape in culture conditions and were dramatically reduced in cell number. SNP treatment also increased levels of apoptotic marker protein, such as Bax and cytochrome c, and reduced caspase-3 in PDLFs. Mitogen-activated protein kinase signaling was activated by treatment of SNP and NMDA receptor antagonist. Conclusions: These results suggest that excessive production of NO may induce apoptosis and that NMDA receptor may modulate NO-induced apoptosis in PDLFs.

• Journal of Periodontal and Implant Science
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• v.41 no.4
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• pp.167-175
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• 2011

Purpose: Periodontal ligament (PDL) cell differentiation into osteoblasts is important in bone formation. Bone formation is a complex biological process and involves several tightly regulated gene expression patterns of bone-related proteins. The expression patterns of bone related proteins are regulated in a temporal manner both in vivo and in vitro. The aim of this study was to observe the gene expression profile in PDL cell proliferation, differentiation, and mineralization in vitro. Methods: PDL cells were grown until confluence, which were then designated as day 0, and nodule formation was induced by the addition of 50 ${\mu}g$/mL ascorbic acid, 10 mM ${\beta}$-glycerophosphate, and 100 nM dexamethasone to the medium. The dishes were stained with Alizarin Red S on days 1, 7, 14, and 21. Real-time polymerase chain reaction was performed for the detection of various genes on days 0, 1, 7, 14, and 21. Results: On day 0 with a confluent monolayer, in the active proliferative stage, c-myc gene expression was observed at its maximal level. On day 7 with a multilayer, alkaline phosphatase, bone morphogenetic protein (BMP)-2, and BMP-4 gene expression had increased and this was followed by maximal expression of osteocalcin on day 14 with the initiation of nodule mineralization. In relationship to apoptosis, c-fos gene expression peaked on day 21 and was characterized by the post-mineralization stage. Here, various genes were regulated in a temporal manner during PDL fibroblast proliferation, extracellular matrix maturation, and mineralization. The gene expression pattern was similar. Conclusions: We can speculate that the gene expression pattern occurs during PDL cell proliferation, differentiation, and mineralization. On the basis of these results, it might be possible to understand the various factors that influence PDL cell proliferation, extracellular matrix maturation, and mineralization with regard to gene expression patterns.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.375-383
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• 2006

사람치주인대섬유모세포(human periodontal ligament fibroblast, PDLF)의 기능 손상과 클로르헥시딘(Chlorhexidine, CHX)의 세포독성에 관한 분자적인 기전은 최근까지도 불명확하다. 이 연구의 목적은 PDLF에 의한 골결절 형성에 있어서 CHX의 효과를 평가하고, 치주수술후에 치주병원균의 최소억제농도(minimal inhibitory concentration, MIC)를 평가하고자 하였다. CHX의 세포독성을 평가하기 위해서 MTT assay법을 실시하였다. CHX은 0.12%에서 0.00012%까지, 즉 10-1000배로 희석시킨 후 30, 60, 120초 동안 PDLF에 적용되었고, 석회화된 결절은 alizarin red 용엑에 염색되었다. 치주병원균에 대한 CHX의 MIC가 평가되었다. 이 연구 결과, 세포생존율 검사에서는, 단지 0.12% CHX 에 노출되었던 세포들만 세포 증식 소견을 다소 나타내었다. 모든 CHX 농도(0.12%-0.00012%)에서 PDLF에 의한 골결절 형성은 의미있는 감소를 나타내었다. 또한 치주병원균에 대한 CHX의 MIC는 0.0012%로 나타났다. PDLF의 골결절 형성에 영향을 주는 농도(0.00012%)는 세포독성을 나타내는 농도(0.12%)보다 더 낮은 농도를 보였고, 치주병원균의 최소억제에 필요한 농도는 0.0012%로 나타났다. 이런한 결과들은 통상적으로 상용되는CHX이 PDLF에 의한 골결절 형성에 있어서 영향을 미칠 수 있음을 시사하였다.

• Journal of Periodontal and Implant Science
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• v.35 no.4
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• pp.1003-1017
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• 2005

이 논문은 단일조사 저출력 $CO_2$ Laser조사가 치주인대 섬유아세포의 증식과 분화에 미치는 영향을 살펴보고 가장 효과적인 에너지와 파워밀도(power density)를 알아보기 위해 다음과 같이 실험하였다. 0.5W 출력, 10.6 ${\mu}m$ 파장, 50 Hz 연속형 $CO_2$ Laser를 사용하여, 실험군은 laser tip과 배양된 세포 사이의 거리를 2cm, 3cm으로 나누고, 조사시간을 1초, 3초로 나누어 4개의 군으로 설정하였고 대조군은 laser를 조사하지 않은 군으로 하였다. 치주인대 섬유아세포의 증삭정도와 골모세포로의 분화정도를 보기 위하여 각각 MTT 실험과 ALP activity 실험을 시행하여 다음과 같은 결과를 얻었다. 1. Laser를 조사하고 난 후 5일째에, 모든 군에서 유의하게 세포가 증식되는 것을 확인할 수 있었고 조사방법간에 유의한 차이가 없었다. 2. 대조군과 살험군에서 0일째에 비하여 3일째, 5일째, 7일째, 10일째에 통계적으로 유의 하게 ALP activity가 증가하였고, 이중 2cm,1sec 군을 제외하면 3일째에서 가장 높은 ALP activity 값을 보였다. 특징적으로 2cm,1sec 군은 3일째부터 10일까지 통계적으로 유의하지는 않지만 시간이 지남에 따라서 ALP activity가 증가함을 보였다. 7일과 10일째에는 2cm,1sec, 3cm,3sec군에서 다른 군에 비하여 큰 activity값을 보였다. 이번실험에서 저출력 $CO_2$ Laser 조사는 세포의 증식보다는 분화에 더 큰 영향을 끼쳤고, 2cm, 1sec, 3cm, 3sec 군이 치주인대 섬유아세포의 분화에 가장 효과적인 laser 조사방법으로 분석되었다.