• Journal of Periodontal and Implant Science
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• 제50권6호
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• pp.392-405
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• 2020

Purpose: Titanium implants are widely used in the treatment of dentition defects; however, due to problems such as osseointegration failure, peri-implant bone resorption, and periimplant inflammation, their application is subject to certain restrictions. The surface modification of titanium implants can improve the implant success rate and meet the needs of clinical applications. The goal of this study was to evaluate the effect of the use of porous titanium with a chitosan/hydroxyapatite coating on osseointegration. Methods: Titanium implants with a dense core and a porous outer structure were prepared using a computer-aided design model and selective laser sintering technology, with a fabricated chitosan/hydroxyapatite composite coating on their surfaces. In vivo and in vitro experiments were used to assess osteogenesis. Results: The quasi-elastic gradient and compressive strength of porous titanium implants were observed to decrease as the porosity increased. The in vitro experiments demonstrated that, the porous titanium implants had no biological toxicity; additionally, the porous structure was shown to be superior to dense titanium with regard to facilitating the adhesion and proliferation of osteoblast-like MC3T3-E1 cells. The in vivo experimental results also showed that the porous structure was beneficial, as bone tissue could grow into the pores, thereby exhibiting good osseointegration. Conclusions: Porous titanium with a chitosan/hydroxyapatite coating promoted MC3T3-E1 cell proliferation and differentiation, and also improved osseointegration in vitro. This study has meaningful implications for research into ways of improving the surface structures of implants and promoting implant osseointegration.

• 대한구강악안면병리학회지
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• 제42권6호
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• pp.189-198
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• 2018

A 31 years old female had been suffered from a bony swelling in right premolar region of the mandible for 12 years, recently grown rapidly. A fistula tract developed on the right anterior mandibular border, but the lesion was relatively asymptomatic. In the radiological examination, the tumor mass was irregularly mixed with radiolucent and radiopaque areas, forming multiple cystic spaces. Under the diagnosis of calcifying odontogenic cyst, the mandibular mass was resected and examined pathologically. After decalcification, the dissected tumor mass showed multiple small cystic spaces and calcifying fibrous tissue, mimicking calcifying odontogenic cyst or ameloblastoma. Histological observation showed many calcifying cementoid materials and ossifying trabeculae. The cystic spaces were turned out to be dilated vascular channels lined by endothelial cells, containing plasma fluid. However, the main lesion was diagnosed as cemento-ossifying fibroma (COF), and the atypical vascular channels were greatly dilated and gradually expanded the whole tumor mass. The present COF was examined through immunohistochemical (IHC) array, and investigated for tumor cell characteristics, exhibiting abnormal ossification and aneurysmal cystic changes. IHC array disclosed that the tumor cells grew progressively in the lack of apoptosis, and that they showed lower expression of RUNX2 than BMP-2, RANKL, and OPG, and increases of protein expression in $HIF-1{\alpha}$, VEGF-A, and CMG2. These data suggested that the reduced expression of RUNX2, osteoblast differentiation factor, be relevant to abnormal ossification of COF, and that the consistent expressions of angiogenesis factors be relevant to de novo angiogenesis in COF, subsequently resulted in aneurysmal cystic changes.

• Imaging Science in Dentistry
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• 제36권4호
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• pp.189-198
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• 2006

Purpose: To investigate the in vitro response of MC3T3-E1 osteoblastic cells to X-ray in the presence and absence of 2 deoxy-D-glucose (2-DG) and quercetin (QCT). Materials and Methods: The MC3T3-E1 cells were cultured in an ${\alpha}-MEM$ supplemented with 5 mM 2-DG or $10{\mu}M$ QCT and then the cells were incubated for 12 h prior to irradiation with 2, 4, 6, and 8Gy using a linear accelerator (Mevaprimus, Germany) delivered at a rate of 1.5 Gy/min. At various times after the irradiation, the cells were processed for the analyses of proliferation, viability, cytotoxicity, and mineralization. Results: Exposure of the cells to X-ray inhibited the tritium incorporation, 3-(4, 5-dimethylthiazol-2yl-)-2, 5-diphenyl tetrazolium bromide (MTT)-reducing activity, and alkaline phosphatase (ALP) activity, and caused cytotoxicity and apoptosis in a dose-dependent manner of the X-ray. This effect was further apparent on day 3 and 7 after the irradiation. RA+2-DG showed the decrease of DNA content, cell viability, and increase of cytotoxicity rather than RA. ALP activity increased on day 7 and subsequently its activity dropped to a lower level. 2-DG suppressed the calcium concentration, but visual difference of number of calcified nodules between RA and RA+2-DG was not noticed. RA+QCT showed the increase of DNA content, cell viability, but decrease of cytotoxicity and subG1 stage cells in the cell cycle, and increased calcified nodules in von Kossa staining rather than the RA. ALP activity showed significant increases on day 7 and subsequently its activity dropped to a lower level. Conclusion: The results showed that the 2-DG acted as a radiosensitizing agent and QCT acted as a radiosensitizing agent respectively in the irradiated MC3T3-E1 osteoblast-like cells.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권3호
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• pp.217-224
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• 2008

Angiogenesis plays an important role in bone development and postnatal bone fracture repair. Vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptors (VEGFRs) have been thought to be primarily involved in promoting angiogenesis. It is well known that VEGF and its receptors have been reported to play an important role in the regulation of the interaction between angiogenesis and osteogenesis during bone repair processes. Dexamethasone, a potent synthetic glucocorticoid, promotes phenotype markers of osteoblast differentiation, such as ALP and osteocalcin. It stimulates in vitro osteogenesis of human bone marrow osteogenic stromal cells. Dexamethasone has been reported to suppress VEGF gene expression in some cells. However, our previous study demonstrated VEGF quantification increased in a time-dependent manner in periosteal-derived osteogenesis under dexamethasone. So, the purpose of this study was to examine the angiogenic phenotypes in cultured human periosteal-derived cells under high-dose dexamethasone. Periosteal-derived cells were cultured using a technique previously described. After passage 3, the periosteal-derived cells were further cultured for 28 days in an osteogenic inductive culture medium containing ascorbic acid, ${\beta}$-glycerophosphate and high-dose dexamethasone, We evaluated the expression of VEGF isoforms, VEGFR-1, VEGFR-2, and neuropilin-1, ALL VEGF isoforms ($VEGF_{121},\;VEGF_{165},\;VEGF_{189}$, and $VEGF_{206}$) expression was observed by RT-PCR analysis. VEGFR-1, VEGFR-2 and neuropilin-1 expression increased up to day 14, particularly during the early stage of mineralization. Our results suggest the involvement of direct VEGFs/VEGFRs system on periosteal-derived cells during early mineralization phase under high-dose of dexamethasone. These also suggest that VEGF might act as an autocrine growth molecule during osteoblastic differentiation of cultured human periosteal-derived cells.

• Journal of Periodontal and Implant Science
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• 제31권4호
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• pp.787-801
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• 2001

The molecular mechanisms control the function of PDL(periodonta1 ligament) cells and/or fibroblasts remain unclear. PDLsl7, PDL-specific gene, had previousely　identified the cDNA for a novel protein from cultured　PDL fibroblasts using subtraction hybridization between gingival fibroblasts and　PDL fibroblasts. The purpose　of this study was to determine the regulation by growth factors and cytokines on　PDLsl7 gene expression in　cultured human periodontal ligament cells and observe the immunohistochemical　localization of PDLsl7 protein in various tissues of mouse. Primary PDL fibroblasts isolated by scraping the root of the extracted human mandibular third molars. The cells were incubated with various concentration of human recombinant $IL-1{\beta}$, PDGF-BB and TGF\;${\beta}$ for 48h nd 2 weeks. At each time point total RNA was extracted and the levels of transcription ere assessed by reverse transcription-polymerase chain reaction (RT-PCR assay). polyclonal antiserum raised against PDLsl7 peptides, CLSVSYNRSYQINE and SEAVHETDLHDGC, were made, and stained the tooth, periodontium, developing bone, bone marrow and mid-palatal suture of the mouse. The results were as follows. 1. PDLsl7 mRNA levels were increased in response to PDGF (10ng/ml) and $TGF\;{\beta}$(20ng/ml) after treatment of the $IL-1{\beta}$, PDGF-BB and $TGF{\beta}$for 48 h. 2. PDLsl7 was up-regulated only by $TGF{\beta}$(20 ng/ml) after treatment of the $IL-1{\beta}$, PDGF-BB and $TGF\;{\beta}$ for 2 weeks and unchanged by the other stimulants. 3. PDLsl7 was a novel protein coding the 142 amino acid peptides in the ORF and the nucleotide sequences of the obtained cDNA from RT-PCR was exactly same as the nucleotides of the database. 4. Immunohistochemical analysis showed that PDLsl7 is preferentially expressed in the PDL, differentiating osteoblast-like cells and stromal cells of the bone marrow in the adult mouse. 5. The expression of PDLsl7 protein was barely detectable in gingival fibroblasts, hematopoetic cells of the bone marrow and mature osteocytes of the alveolar bone. These results suggest that PDLsl7 might upregulated by PDGF-BB or $TGF{\beta}$ and acts at the initial stage of differentiation when the undifferentiated mesenchymal cells in the bone marrow and PDL differentiate into multiple cell types. However, more research needs to be performed to gain a better understanding of the exact function of PDLsl7 during the differentiation of bone marrow mesenchymal and PDL cells.

• 치위생과학회지
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• 제23권4호
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• pp.282-295
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• 2023

Background: Secretory leukocyte protease inhibitor (SLPI) protects tissues from proteases and promotes cell proliferation and healing. SLPI also reduces periodontal inflammation and alveolar bone resorption by inhibiting proinflammatory cytokine expression in rat periodontal tissues and osteoblasts. However, little is known of the role of SLPI in the expression of osteoclast regulatory factors from osteoblasts, which are crucial for the interaction between osteoblasts and osteoclasts. Therefore, we aimed to determine the effects of SLPI on the regulation of osteoclasts and osteoblasts in LPS-treated alveolar bone and osteoblasts. Methods: Periodontitis was induced in rats using LPS. After each LPS injection, SLPI was injected into the same area. Immunohistochemical analysis was performed with antibodies against SLPI, RANKL, OPG, and Runx2 in the periodontal tissue. RT-PCR and western blotting were performed to determine the expression levels of SLPI, RANKL, OPG, and Runx2 in LPS- and SLPI/LPS-treated MC3T3-E1 cells. SLPI/LPS-treated MC3T3-E1 cells were also stained with Alizarin Red S. Results: Immunohistochemical analysis showed that the expression levels of SLPI, OPG, and Runx2 were higher while that of RANKL was lower in the LPS/SLPI group relative to those in the LPS group. The mRNA and protein expression of SLPI, OPG, and Runx2 was higher in SLPI/LPS/MC3T3-E1 cells than in LPS/MC3T3-E1 cells, and RANKL expression was lower. During differentiation, OPG and Runx2 protein levels were higher whereas RANKL levels were lower in SLPI/LPS/MC3T3-E1 than in LPS/MC3T3-E1 cells on days 0, 4, 7, and 10. In addition, mineralization and matrix deposition were higher in SLPI/LPS/MC3T3-E1 than in LPS/MC3T3-E1 on days 7 and 10. SLPI decreased RANKL expression in LPS-treated alveolar bone and osteoblasts but increased the expression of OPG and Runx2. Conclusion: SLPI can be considered as a regulatory molecule that indirectly regulates osteoclast activation via osteoblasts and promotes osteoblast differentiation.

• Journal of Periodontal and Implant Science
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• 제31권4호
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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.

• 생명과학회지
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• 제16권2호
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• pp.231-239
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• 2006

인체의 골수내에 존재하는 중간엽 줄기세포는 성장인자나 환경적 요인에 의해 지방세포, 골아세포, 연골모세포 및 연골세포 등으로 분화됨이 알려져 있다. 본 연구에서는 정상 인체의 골수으로 얻어진 중간엽 줄기세포로부터 골아세포의 분화 가능성을 알아보고 이에 관여하는 유전자의 발현을 조사하였다. 정상 골수의 중간엽 줄기세포를 골유도성 자극보조제로서 $\beta$-glycerol phosphate, L-ascorbic acid 및 dexamethasone을 첨가하여 골아세포로의 분화를 유도한 세포와 골유도성 자극보조제를 첨가하지 않은 세포를 배양하여 일정 간격으로 cDNA microarray를 이용하여 각각의 단계에서 발현되는 유전자를 검사하고 이로 인해 얻어진 유전자의 발현량을 분석하기 위해 real time quantitative RT-PCR 을 시행하였다. 골유도성 자극보조제를 첨가한 군에서 첨가하지 않은 군에 비하여 정상적인 골아세포로의 성장이 유도되었고, 분화과정에서 36개의 유전자의 발현이 증가되었고, 59개의 유전자의 발현이 억제되었다. 주로 골 생성 과정과 연관이 있다고 알려진 osteoprotegerin, LRP5 및 metallothionein 2A 등의 유전자들이 분화과정에서 발현 증가되어 나타났고, 줄기세포로부터 분화될 수 있는 조직들 중 근육, 지방, 연골, 혈관 및 신경 조직과 연관된 유전자들은 분화 후기에 감소하거나 혹은 전분화 과정 동안 발현이 억제되었다. 본 연구에서는 골아세포의 분화와 연관된 유전자 발현을 확인함으로써 특정 조건하에서 중간엽 줄기세포로부터 골아세포로의 분화가 가능함을 확인할 수 있었고, 이 과정에 관련된 특정 유전자의 발현 양상을 밝힐 수 있었다.

• 생명과학회지
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• 제24권3호
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• pp.297-303
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• 2014

대황(Eisenia bicyclis)은 온대 태평양에 서식하며 우리나라에서는 울릉도 일대에서 주로 발견 되는 갈조류이다. 대황은 칼슘 함량이 가장 높고 요오드, 철, 마그네슘뿐만 아니라 많은 미네랄과 비타민을 포함하고 있다. 본 연구에서는 대황 추출물을 이용하여 세포 수준에서 대황의 골 형성에 미치는 영향을 검토하였다. MTT 분석법에 의한 조골세포 증식률에서는 대황 에탄올 추출물 10 ${\mu}g/ml$ 처리하였을 때 128%의 높은 활성을 나타내었다. 반면 열수추출물 첨가군에서는 에탄올 추출물에 비해 유의적으로 낮은 활성을 나타내었고, 첨가 농도가 증가할수록 감소되는 결과를 보였다. 대황 추출물의 농도에 따른 석회화 형성에 미치는 영향을 검토한 결과, 대황의 에탄올 추출물 1~100 ${\mu}g/ml$의 범위에서 시료를 처리 하지 않은 대조군에 비해 높은 골석회화 형성능을 나타내었다. 또한, 적색의 석회화 형성 부위를 현미경을 통해 관찰한 결과, 대황의 에탄올 추출물을 처리 하였을 때, 시료를 처리하지 않은 대조군 보다 붉은 색의 반점이 많이 형성된 것을 확인할 수 있었다. 한편, ALP 활성에서는 에탄올 추출물 50 ${\mu}g/ml$에서 179% 활성을 나타내었다. 파골세포인 RAW 264.7 세포를 이용하여 세포 증식률을 측정한 결과, 대황 열수추출물의 경우 1~200 ${\mu}g/ml$의 모든 농도에서 대조군과 비교하여 유의적으로 감소하여 파골세포의 증식억제 효과가 나타났다. 파골세포의 분화형태를 측정하고자 TRAP 효소 활성을 측정한 결과, 열수 및 에탄올 추출물의 10 ${\mu}g/ml$이상의 농도에서 대조군에 비해 감소하는 경향을 나타내었다. 대황 추출물의 첨가 농도가 증가함에 따라 파골세포의 증식이 감소된 결과와 마찬가지로 파골세포의 분화 지표인자인 TRAP활성 역시 농도가 증가함에 따라 감소함을 알 수 있었다. 이상의 결과, 대황 추출물이 조골세포의 증식, 분화유도와 석회화능을 촉진하고 파골세포의 증식 및 분화를 억제시킨다는 것을 알 수 있었다. 향후 대황 추출물 중의 활성성분들의 규명과 in vivo 연구가 병행된다면 조골세포의 증식과 파골세포의 억제에 관여할 수 있는 기능성 식품의 천연소재로 개발이 가능하리라 사료된다.

• 대한한의학방제학회지
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• 제25권2호
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• pp.223-251
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• 2017

Objectives : A lot of experiment results of Yugmijihwangtang(YM) are reported in various kinds of journals. Many of them report on the new effects that are not recorded in the traditional medical texts. So it is necessary to take it into consideration that newly reported effects could be of help to clinical practice, because this process of comparison of Donguibogam and scientific experiment results will have basis to lead into the evidence based medicine. Methods : We compared the effects of in Donguibogam and the experiment results of YM. Results : The effects of YM in Donguibogam are to replenish essence and marrow, and to treat red wen, fatigue, treat hypouresis, urinary sediment, urinary urgency, hematuria, hydrocephalus, speech and movement retardation, yin-deficiency, diabetes mellitus, nonalcoholic fatty liver, melanoma, disability to see near and far sight, tinnitus, hearing loss, alopecia, angiogenesis, cough, cough at night, trachyphonia, and, infantile convulsion. The experiment results of YM since 2000 in both Korea and China are to inhibit atopic dermatitis, renal interstitial fibrosis, anti-oxidant, emphysema, stress, glomerulosclerosis, diabetic nephropathy, chronic glomerulonephritis, hemorrhage, plantar sweating, dermal aging, kidney aging, bone loss, breast cancer, pathological myocardial cell, primary liver cancer, thrombosis, osteoporosis, intrauterine growth retardation, chronic renal failure, IgA nepropathy, slow cerebral development, and hippocampal tissue lesions on the one hand, and to help bone formation, renin-angiotensin- aldosterone system, cerebral recovery, cognitive function and expression, osteoblast proliferation and differentiation, learning and memory, cold-tolerance and oxygen deficit-tolerance and anti-fatigue, endometrial formation, humoral and cell-mediated immunity, immune regulation effect, Hypothalamus-Pituitary-Ovary Axis, and spermatogenesis, on the other hand. Conclusion : When we compared the effects of YM with the experiment results of YM, there existed a considerable gap between them. So, from now on, it is expected that a great effort and consideration are needed to solve these gaps from an academic and clinical point of view.