• 제목/요약/키워드: Osteoblastic cell

검색결과 227건 처리시간 0.033초

IGF-I으로 처리한 치은 및 치주인대 섬유모세포가 골모세포에 미치는 영향 (The Effect of the IGF-I treated Gingival and Periodontal Ligament Fibroblast on Osteoblasts)

  • 김미정;양원식
    • 대한치과교정학회지
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    • 제31권6호
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    • pp.589-600
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    • 2001
  • 이 연구의 목적은 IGF-I의 골모세포에 대한 직접적 작용효과와 IGF-I이 섬유모세포에 작용된 후 섬유모세포에서 유리된 인자를 포함한 조절 배양액이 골모세포에 어떤 영향을 미치는지에 대해 각각 치주인대 섬유모세포와 치은 섬유모세포를 이용하여 알아본 후, 치조골의 반응을 외적자극과의 사이에서 매개하는 치주인대의 주세포군인 섬유모세포를 통한 IGF-I의 골모세포에 대한 영향을 알아보는 것이다. 이를 위해 치주인대 섬유모세포와 치은 섬유모세포를 6-8주된 백서(Sprague-Dawley rat)에서 채집하고, 골모세포는 태생 21일된 동종백서에서 채집하여 기본배양을 한 후, 각 군을 6군으로 분리하여 $1{\times}10^4$/we11, (1ml/well)세포수로 분주한 골모세포 배양접시에 IGF-I을 1,10,100ng/m1로 각각 농도를 달리하여 그 효과를 알아보았다. 각각의 군은 대조군, IGF-I을 직접 투여한 골모세포 배양군, 치주인대 섬유모세포의 조절배양액을 이용한 골모세포 배양군, IGF-I으로 처리한 치주인대 섬유모세포의 조절배양액을 이용한 골모세포 배양군, 치은 섬유모세포의 조절배양액을 이용한 골모세포 배양군, IGF-I으로 처 리한 치은 섬유모세포의 조절배양액을 이용한 골모세포 배양군이다. 조절배양액은 배양 36시간후(IGF-I 처리후 12시 간 배양 포함) 채집하였고, 마지막으로 IGF-I 및 조절배양액으로 처리한 후에 추가 24시간 배양한 후, Alkaline phoaphatase 활성도, Western blot 을 이용한 BMP발현, MTT를 이용한 세포증식, BCA kit을 이용한 총단백질량 측정, Western blot을 이용한 교원질 합성 계측 및 골결절의 생성을 관찰하였다. 본 연구의 결과는 다음과 같다. 1 Alkaline phosphatase활성은 10, 100ng/m1의 IGF-I으로 처리한 군과 치주인대 섬유모세포의 조절배양액을 이용한 군, IGF-I으로 처리한 치주인대 섬유모세포의 조절배양액을 이용한 군에서 대조군보다 더 높게 나타났다. 10, 100ng/ml의 IGF-I으로 처리한 치주인대 섬유모세포의 조절배양액을 이용한 실험군에서 유의성 있게 높게 나타났다. 2. 100ng/m1농도의 IGF-I으로 직접 처리한 군에서 골모세포증식이 유의성 있게 증가하였다. 3. 총단백질량은 IGF-I투여와 상관없이 대조군, 실험군 모두 유사하였다. 4. 모든 실험군에서 BMP2,4가 발현되었고, 대조군과 유의한 차이는 없었다. 이상의 결과에서 IGF-I의 투여여부와는 상관없이 치주인대 섬유모세포가 유리하는 물질이 골모세포의 활성을 증가시키는 것으로 나타났으며, IGF-I은 고농도일때만 유의성있게 골모세포 활성을 촉진함을 알 수 있었다. 따라서 이 연구를 통하여 치주인대 섬유모세포가 골모세포활성을 촉진 시키는 작용을 가지고 있음이 확인되었다.

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A Study on Bone Formation & Osteoporosis by Taeyoungion-Jahage Extracts

  • ;;;;;박영덕
    • 대한한방부인과학회지
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    • 제15권4호
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    • pp.45-60
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    • 2002
  • 생쥐의 calvarial osteoblast세포를 분리배양하여 gelatinase생성여부를 골흡수과정에서의 역할을 규명하기 위하여 SDS-PAGE-zymography분석을 한 결과 progelatinase-A를 항속적으로 합성하고 있음을 확인하였다. 생쥐의 osteoblasts를 골재흡수 약물인 PTH, $1,25(OH)_2D_3$, 단핵구배양액 (MCM) 그리고 IL-1으로 자극시키면 gelatinase생산을 촉진하여 콜라겐분해가 증가되었으나, indomethacin과 dexamethasone은 생쥐의 osteoblastic세포의 collagenolysis를 저해하였다. 한편, 골재흡수에 IL-1을 생쥐태아 유래의 장골조직배양 (fetal mouse long bone organ culture)에 처리하자 IL-1 은 골재흡수를 촉진하였다. 더우기, $IL-1{\alpha}$의 농도의존성에 대한 indomethacin과 dexametasone의 영향을 검토한 결과 직선형의 비례커브로 영향을 미쳤다. 이러한 골대사의 지견을 바탕으로 대영전-자하거의 열수추출물의 시험관내 독성검사에서 $1-200\;{\mu}g/ml$의 농도에서는 독성이 없었으며, 또한, $300\;{\mu}g/ml$ 농도에서도 생쥐의 calvarial골에는 독성이 없었다. 대영전-자하거 extract는 PTH (2 units/ml), MCM (5%, v/v), $rhIL-1{\alpha}$ (1 ng/ml) $1,25(OH)_2D_3$ (10 ng/ml)처리에 대해서 그리고 $IL-1{\alpha}$$IL-1{\beta}$-유발 collagenolysis에 대해서도 보호효과가 있었다. 대영전-자하거extract을 1시간동안 전처리와 후처리에서 콜라겐분해에 약간의 보호활성이 있었으며 $IL-1{\alpha}$$IL-1{\beta}$에 의해 유발되는 콜라겐분해에 보호활성이 보였다. 1시간동안 전처리는 콜라겐분해를 감소시키며, 대영전-자하거 extract는 gelatinase효소를 저해하였으며 PTH, $1,25(OH)_2D_3$, $IL-1{\beta}$$IL-1{\alpha}$로 유발된 효소활성화가 저해되었다. 즉, 대영전-자하거 extracts는 $IL-1{\alpha}-$$IL-1{\beta}$에 의해 촉진되는 골재흡수에 효과적이었으며, 비스테로이드성 항염증제제 (indomethacin 과 dexamethasone)에 의한 골재흡수방지 효과와 유사하였다. 이러한 결과는 대영전-자하거extract가 골다공증치료에 효과적임을 나타내는 것이다.

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PSII를 이용한 마그네슘 이온 주입 임플란트에 대한 MC3T3-E1 골모양 세포 반응 연구 (Cell study on the Magnesium ion implanted surface with PSII)

  • 신형주;김대곤;박찬진;조리라;이희수;차민상
    • 구강회복응용과학지
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    • 제25권4호
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    • pp.361-374
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    • 2009
  • 임플란트와 골 반응을 개선하기 위한 생화학적 표면 처리 방법으로 다양한 이온을 이용한 이온주입법에 대한 관심이 높아지고 있다. 본 연구는 플라즈마 상태의 마그네슘 이온을 임플란트 표면에 주입하여 이온 피막을 형성하는 방법으로 표면 처리를 한 임플란트에 대한 MC3T3-E1 골모양 세포의 초기 반응을 평가해 보고자 하였다. 티타늄 디스크를 네 가지 군으로 표면처리를 달리하였다. A군은 연마만 하였고 B군은 연마 후 마그네슘 이온을 주입하였다. C군은 알루미늄 입자분사 하였고, D군은 알루미늄 입자분사 후 마그네슘 이온을 주입하였다. 조골세포의 반응을 세포 부착, 증식, 분화의 단계별로 평가하였다. 세포 부착을 평가하기 위해 MC3T3-E1 골모양 세포를 4시간, 24시간, 48시간 금속 표면에서 배양하여 주사현미경으로 관찰하였다. 세포분화도평가는 세포를 4일간 배양 후 알칼리성 인산분해효소 활성도 분석을 통해 시행하였다. 세포외기질의 세포내 발현은 RT-PCR을 통해 평가하였다. 이상의 실험에서 다음과 같은 결과를 얻었다. 1. 주사현미경 관찰시 시간의 흐름에 따라 세포 부착량은 증가하였으며, 마그네슘 이온을 주입한 시편에서 더 많은 양 세포 증식이 관찰되었으며 분화정도도 더 높은 것으로 관찰되었다. 2. RT-PCR 분석시 알루미늄 입자분사 후 마그네슘 이온을 주입한 시편에서 c-fos와 osteonectin의 발현이 증가된 소견을 보였다. 3. 알칼리성 인산분해효소 활성도 분석시 금속 표면처리 방법에 따른 차이는 발생하지 않았다. 이상의 결과를 종합하면 Mg 이온이 주입된 군의 세포가 Mg 이온이 주입되지 않은 군보다 초기의 세포반응이 더 우수하다는 것을 알 수 있다.

혈관내피세포 채취의 원천으로 인간 지방조직의 활용 (Use of Human Adipose Tissue as a Source of Endothelial Cells)

  • 박봉욱;하영술;김진현;조희영;정명희;김덕룡;김욱규;김종렬;장중희;변준호
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제32권4호
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    • pp.299-305
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    • 2010
  • Purpose: Adipose tissue is located beneath the skin, around internal organs, and in the bone marrow in humans. Its main role is to store energy in the form of fat, although it also cushions and insulates the body. Adipose tissue also has the ability to dynamically expand and shrink throughout the life of an adult. Recently, it has been shown that adipose tissue contains a population of adult multipotent mesenchymal stem cells and endothelial progenitor cells that, in cell culture conditions, have extensive proliferative capacity and are able to differentiate into several lineages, including, osteogenic, chondrogenic, endothelial cells, and myogenic lineages. Materials and Methods: This study focused on endothelial cell culture from the adipose tissue. Adipose tissues were harvested from buccal fat pad during bilateral sagittal split ramus osteotomy for surgical correction of mandibular prognathism. The tissues were treated with 0.075% type I collagenase. The samples were neutralized with DMEM/and centrifuged for 10 min at 2,400 rpm. The pellet was treated with 3 volume of RBC lysis buffer and filtered through a 100 ${\mu}m$ nylon cell strainer. The filtered cells were centrifuged for 10 min at 2,400 rpm. The cells were further cultured in the endothelial cell culture medium (EGM-2, Cambrex, Walkersville, Md., USA) supplemented with 10% fetal bovine serum, human EGF, human VEGF, human insulin-like growth factor-1, human FGF-$\beta$, heparin, ascorbic acid and hydrocortisone at a density of $1{\times}10^5$ cells/well in a 24-well plate. Low positivity of endothelial cell markers, such as CD31 and CD146, was observed during early passage of cells. Results: Increase of CD146 positivity was observed in passage 5 to 7 adipose tissue-derived cells. However, CD44, representative mesenchymal stem cell marker, was also strongly expressed. CD146 sorted adipose tissue-derived cells was cultured using immuno-magnetic beads. Magnetic labeling with 100 ${\mu}l$ microbeads per 108 cells was performed for 30 minutes at $4^{\circ}C$ a using CD146 direct cell isolation kit. Magnetic separation was carried out and a separator under a biological hood. Aliquous of CD146+ sorted cells were evaluated for purity by flow cytometry. Sorted cells were 96.04% positivity for CD146. And then tube formation was examined. These CD146 sorted adipose tissue-derived cells formed tube-like structures on Matrigel. Conclusion: These results suggest that adipose tissue-derived cells are endothelial cells. With the fabrication of the vascularized scaffold construct, novel approaches could be developed to enhance the engineered scaffold by the addition of adipose tissue-derived endothelial cells and periosteal-derived osteoblastic cells to promote bone growth.

쥐의 골수로부터 추출한 줄기세포를 이용한 조골세포로의 분화 유도과정에서 나타난 문제점에 관한 분석 연구 (PROBLEMS IN OSTEOGENIC DIFFERENTIATION OF RAT BONE MARROW STROMAL CELLS)

  • 김인숙;조태형;장옥련;이규백;박용두;노인섭;;이종호;김명진;황순정
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제27권1호
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    • pp.1-8
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    • 2005
  • This study was aimed to characterize osteogenic potential of rat bone marrow stromal cells (BMSC) isolated with standard flushing method and investigate the plasticity of transdifferentiation between osteoblastic and adipocytic lineage of cultured BMSC. Unlike aspiration method in human, rat bone marrow was extracted by means of irrigation with culture media that elevates the possibility of co-extraction of committed osteoprogenitor, or preosteoblast or other progenitor cells of several types present inside bone marrow. The cultured stromal cells showed high ALP activity which is representative marker of osteoblast without any treatment. Osteogenic inducers such as Dex and BMP-2 were examined for the evaluation of their effect on osteogenic and adipocytic differentiation of stromal cells, because they function as osteoinductive agent in stromal cells, but simultaneously induce adipogenic differentiation. Osteogenic differentiation was evaluated by measuring alkaline phosphatase activity or mRNA expression of osteoblast markers such as osteopontin, bone sialoprotein, collagen type I and CbfaI, and in vitro matrix mineralization by von Kossa staining. Oil red staining method was used to detect adipocyte and adipocytic marker, aP2 and $PPAR{\gamma}2$ expression was examined using RT-PCR. It can be supposed that irrigation procedure resulted in high portion of already differentiation-committed osteoprogenitor cell showing elevated ALP activity and strong mineralization only under the supplement of $100{\mu}M$ ascorbic 2-phosphate and 10mM ${\beta}$-glycerophosphate without any treatment of osteogenic inducers such as Dex and BMP-2. Dex and BMP-2 seemed to transdifferentiate osteoprogenitor cells having high ALP activity into adipocytes temporarily, but continuous treatment redifferentiated into osteoblast and developed in vitro matrix mineralization. This property must be considered either in tissue engineering for bone regeneration, or in research of characterization of osteogenic differentiation, with rat BMSC isolated by the standard irrigation method.

속단의 dichloromethane 분획물이 태아골모세포의 골형성 유도에 미치는 효과 (Effects of Dichloromethane Fraction of Phlomidis Radix on Bone Formation in Human Fetal Osteoblasts)

  • 이영준;최희인;김윤철;신형식;유형근
    • Journal of Periodontal and Implant Science
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    • 제33권2호
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    • pp.259-269
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    • 2003
  • The ideal goal of periodontal therapy is the regeneration of periodontal tissue repair of function. Although is very difficult to attain the goal, recent advances in periodontal wound healing concepts encourage hope reaching it. Recently many efforts are concentrated on the regeneration potential of material used in traditional Korean medicine. Phlomidis Radix has been used for the treatment of blood stasis, bone fracture and osteoporosis in traditional Korean medicine. The purpose of this study is to examine effects of dichloromethane fraction Phlomidis Radix on Bone Formation in Human Fetal Osteoblasts. Human fetal osteoblastic cell line(hFOB1 1.19 ;American Type Culture Collection, Manassas, VA) were used and cells were cultured containing DMEM and dichloromethane fraction Phlomidis Radix(100 ng/ml , 1 ${\mu}$/ml, 10 ${\mu}$/ml) at 34$^{\circ}C$ with 5% $CO_2$ in 100% humidity. MTT was performed to examine the viability of the cell, and alkaline phosphatase activity was analyzed to examine the mineralization. Also bone calcification nodules were evaluated. The cellular activity of hFOB1 was increased in 100 ng/ml, 1 ${\mu}$/ml , 10 ${\mu}$/ml of dichloromethane fraction of Phlomidis Radix and especially significant increation was showed in 100 ng/ml of dichloromethane fraction of Phlomidis Radix at 6days (p <0.05). ALP level of hFOB1 was significantly increased in 100 ng/ml , 1 ${\mu}$/ml, 10 ${\mu}$/ml of dichloromethane fraction of Phlomidis Radix and especially more increation was showed in 10 ${\mu}$/ml of dichloromethane fraction of Phlomidis Radix (p <0,05). Calcification nodules of hFOB1 significantly increased in 10 ${\mu]$/ml of dichloromethane fraction of Phlomidis Radix at 21 days of incubation(p<0.05). The results indicate that dicholoromethane fraction of Phlomidis Radix has excellent effects on mineralization of hFOB1.

인간 골막기원세포와 Polydioxanone/Pluronic F127 담체를 이용한 골형성 (In vivo Osteogenesis of Cultured Human Periosteal-derived Cells and Polydioxanone/Pluronic F127 Scaffold)

  • 박봉욱;이진호;오세행;김상준;하영술;전령훈;맹건호;노규진;김종렬;변준호
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제34권6호
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    • pp.384-390
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    • 2012
  • Purpose: The purpose of this study is to examine in vivo osteogenesis of cultured human periosteal-derived cells and polydioxanone/pluronic F127 scaffold. Methods: Two one-year-old miniature pigs were used in this study. $2{\times}10^6$ periosteal-derived cells in 1 mL medium were seeded by dropping the cell suspension into the polydioxanone/pluronic F127 scaffold. These cell-scaffold constructs were cultured in osteogenic Dulbecco's modified Eagle's medium for 7 days. Under general anesthesia with azaperone and tiletamine-zolazepam, the mandibular body and ramus of the pigs were exposed. Three bony defects were created. Polydioxanone/pluronic F127 scaffold with periosteal-derived cells and the scaffold only were implanted into each defect. Another defect was left empty. Twelve weeks after implantation, the animals were sacrificed. Results: New bone formation was clearly observed in the polydioxanone/pluronic F127 scaffold with periosteal-derived cells. Newly generated bone was also observed in the scaffold without periosteal-derived osteoblasts and empty defect, but was mostly limited to the periphery. Conclusion: These results suggest that cultured human periosteal-derived cells have good osteogenic capacity in a polydioxanone/pluronic F127 scaffold, which provides a proper environment for the osteoblastic differentiation of these cells.

골수유래줄기세포에서 분화된 골유사세포에서 ${\beta}-TCP$와 rhBMP-2의 골형성 효과에 관한 연구 (THE EFFECTS OF ${\beta}-TCP$/rhBMP-2 ON BONE FORMATION IN OSTEOBLAST-LIKE CELLS INDUCED FROM BONE MARROW-DERIVED MESENCHYMAL STEM CELLS)

  • 최용수;황경균;이재선;박창주;심광섭
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제34권4호
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    • pp.419-427
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    • 2008
  • The present study aimed to investigate the osteogenic potentials of differentiated osteoblast-like cells (DOCs) induced from bone marrow-derived mesenchymal stem cells (MSCs) on ${\beta}-tricalcium$ phosphate (${\beta}-TCP$) with recombinant human bone morphogenetic protein (rhBMP-2) in vitro. Osteoblast differentiation was induced in confluent cultures by adding 100 nM dexamethasone, 10 mM ${\beta}$-glycerophosphate, 50 mM L-ascorbic acid. The Alizarin red S staining and reverse transcriptase-polymerase chain reaction (RT-PCR) were perfomed to examine the mRNA expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN), receptor activator for nuclear factor ${\kappa}B$ ligand (RANKL), runt-related transcription factor 2 (RUNX2), collagen-Ⅰ (COL-Ⅰ). There were no significant differences in the osteogenic potentials of DOCs induced from MSCs on ${\beta}-TCP(+/-)$. According to the incubation period, there were significant increasing of Alizadin red S staining in the induction 3 weeks. The mRNA expression of ALP, RUNX2, and RANKL were higher in DOCs/${\beta}-TCP(-)$ than DOCs/${\beta}-TCP(+)$. According to rhBMP-2 concentrations, the mRNA expression of BSP was significantly increased in DOCs/${\beta}-TCP(+)$ compared to that of DOCs/${\beta}-TCP(-)$ on rhBMP 10 ng/ml. Our study presented the ${\beta}-TCP$ will have the possibility that calcium phosphate directly affect the osteoblastic differentiation of the bone marrowderived MSCs.

Unique cartilage matrix-associated proteins에 의한 MC3T3-E1 조골세포에서의 고혈당 스트레스 완화 효과 (Unique Cartilage Matrix-Associated Protein Alleviates Hyperglycemic Stress in MC3T3-E1 Osteoblasts)

  • 주현영;박나래;김정은
    • 생명과학회지
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    • 제33권11호
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    • pp.851-858
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    • 2023
  • Unique cartilage matrix-associated protein (UCMA)은 γ-카르복실화(Gla) 잔기가 풍부한 간외 비타민 K 의존 단백질이다. UCMA는 조골세포 분화를 촉진하고 뼈 형성을 강화한다고 보고되고 있지만 고혈당 스트레스 하에서 조골세포에 미치는 영향에 대해서는 아직 알려진 바가 없다. 본 연구에서는 고혈당 조건하에서의 MC3T3-E1 조골세포에서 UCMA 효과를 조사하기 위해 MC3T3-E1 조골세포를 높은 포도당에 노출한 후 재조합 UCMA 단백질을 처리하였다. MC3T3-E1 세포에서 활성 산소종(ROS)의 생성은 고혈당 조건하에서 증가했으나 UCMA 단백질 처리 후 감소했음을 CellROX 및 MitoSOX 염색으로 확인하였다. 또한 고혈당 조건에서 UCMA 단백질을 함께 처리한 MC3T3-E1 세포에서 정량적 중합효소 연쇄반응 결과, 항산화 유전자인 nuclear factor erythroid 2-related factor 2 와 superoxide dismutase 1 발현이 증가하였다. 동일 조건하에서 UCMA 단백질 처리에 의해 heme oxygenase-1 발현 감소와 함께 세포질에서 핵으로의 전위가 감소되었고, 미토콘드리아 분열에 관여하는 dynamin-related protein 1 발현이 증가하였으며, AKT 신호 활성은 억제되었다. 종합적으로 UCMA는 고혈당에 노출된 조골세포에서 ROS 생성을 완화하고, 항산화 유전자 발현을 증가시키고, 미토콘드리아 역학에 영향을 미치며, AKT 신호를 조절하는 것으로 보인다. 본 연구는 UCMA의 세포 메커니즘에 대한 이해를 돕고, 대사 장애 관련한 골 합병증에 대한 새로운 치료제로서의 잠재적 사용 가능성을 제시하고 있다.

배양된 치유두 유래세포의 조골활성 및 골기질 형성의 평가 (EVALUATION OF OSTEOGENIC ACTIVITY AND MINERALIZATION OF CULTURED HUMAN DENTAL PAPILLA-DERIVED CELLS)

  • 박봉욱;변준호;최문정;하영술;김덕룡;조영철;성일용;김종렬
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제29권4호
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    • pp.279-288
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    • 2007
  • In the present study, we focused on stem cells in the dental papilla of the tooth germ. The tooth germ, sometimes called the tooth bud, is the primordial structure from which a tooth is formed. The tooth germ consists of the enamel organ, the dental papilla, and the dental follicle. The dental papilla lies below a cellular aggregation of the enamel organ. Mesenchymal cells within the dental papilla are responsible for formation of dentin and pulp of a tooth. Tooth germ disappears as a tooth is formed, but that of a third molar stays in the jawbone of a human until the age of 10 to 16, because third molars grow slowly. Impacted third molar tooth germs from young adults are sometimes extracted for orthodontic treatment. In the present study, we evaluated the osteogenic activity and mineralization of cultured human dental papilla-derived cells. Dental papillas were harvested from mandible during surgical extraction of lower impacted third molar from 3 patients aged 13-15 years. After passage 3, the dental papilla-derived cells were trypsinized and subsequently suspended in the osteogenic induction DMEM medium supplemented with 10% fetal bovine serum, 50 g/ml L-ascorbic acid 2-phosphate, 10 nM dexamethasone and 10 mM -glycerophosphate at a density of $1\;{\times}10^6\;cells/dish$ in a 100-mm culture dish. The dental papilla-derived cells were then cultured for 6 weeks and the medium was changes every 3 days during the incubation period. Dental papilla-derived cells showed positive alkaline phosphatase (ALP) staining during 42 days of culture period. The formation of ALP stain showed its maximal manifestation at day 7 of culture period, then decreased in intensity during the culture period. ALP mRNA level was largely elevated at 1 weeks and gradually decreased with culture time. Osteocalcin mRNA expression appeared at day 14 in culture, after that its expression continuously increased in a time-dependent manner up to day 28. The expression remained constant thereafter. Runx2 expression appeared at day 7 with no detection thereafter. Von Kossa-positive mineralization nodules were first present at day 14 in culture followed by an increased number of positive nodules during the entire duration of the culture period. Osteocalcin secretion was detectable in the culture medium from 1 week. The secretion of osteocalcin from dental papilla-derived cells into the medium greatly increased after 3 weeks although it showed a shallow increase by then. In conclusion, our study showed that cultured human dental papilla-derived cells differentiated into active osteoblastic cells that were involved in synthesis of bone matrix and the subsequent mineralization of the matrix.