• 대한소아치과학회지
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• 제42권4호
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• pp.312-318
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• 2015

본 연구의 목적은 치과분야에서 줄기세포 공급원으로써 과잉치의 활용 가능성을 알아보고자 Real Time Quantitative Reverse Transcription Polymerase Chain Reaction (Real Time qRT-PCR)법을 이용하여 발치된 과잉치 치수 유래 줄기세포 (supernumerary dental pulp stem cells, sDPSCs)로부터 상아모세포로의 분화여부를 관찰해 보는 것이었다. 이를 위해 상아모세포의 대표적인 발현인자로 알려진 alkaline phosphatase (ALP), osteocalcin (OC), osteonectin (ON), dentin matrix acidic phosphoprotein 1 (DMP-1) 그리고 dentin sialophosphoprotein(DSPP)의 발현을 분화제 처리 후 0일, 8일 그리고 14일째에 각각 Real Time qRT-PCR 법을 통해 상대적인 mRNA의 발현 양을 비교하여 변화 양상을 알아보았다. 또한 Alizarin-red solution 의 염색을 통해 sDPSCs가 분화제 처리 7일, 14일, 21일 그리고 28일째에 석회화 결절을 형성하는 정도를 시각적으로 확인해 보았다. Real Time qRT-PCR 결과 분화제 처리 8일째에 가장 높은 발현 양을 보이다가 14일째에 감소하는 추세를 나타내었으며, Alizarin-red solution 염색 결과는 7일째부터 흐리게 나타나다가 14일째에는 배지 전반에 걸쳐 진하게 염색되는 소견을 보였다. 따라서, sDPSCs를 이용한 연구에서 Real Time qRT-PCR법을 위한 분화제의 처리 기간은 8일 정도가 적절하며, Alizarin-red solution 염색은 14일이 적당한 것으로 사료된다.

• Restorative Dentistry and Endodontics
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• 제40권3호
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• pp.223-228
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• 2015

Objectives: The aim of this study was to investigate the expression of 7 different sirtuin genes (SIRT1-SIRT7) in human dental pulp cells (HDPCs), and to determine the role of SIRTs in the odontoblastic differentiation potential of HDPCs. Materials and Methods: HDPCs were isolated from freshly extracted third molar teeth of healthy patients and cultulred in odontoblastic differentiation inducing media. Osteocalcin (OCN) and dentin sialophosphoprotein (DSPP) expression was analyzed to evaluate the odontoblastic differentiation of HDPCs by reverse transcription-polymerase chain reaction (RT-PCR), while alizarin red staining was used for the mineralization assay. To investigate the expression of SIRTs during odontoblastic differentiation of HDPCs, real time PCR was also performed with RT-PCR. Results: During the culture of HDPCs in the differentiation inducing media, OCN, and DSPP mRNA expressions were increased. Mineralized nodule formation was also increased in the 14 days culture. All seven SIRT genes were expressed during the odontogenic induction period. SIRT4 expression was increased in a time-dependent manner. Conclusions: Our study identified the expression of seven different SIRT genes in HDPCs, and revealed that SIRT4 could exert an influence on the odontoblast differentiation process. Further studies are needed to determine the effects of other SIRTs on the odontogenic potential of HDPCs.

• Restorative Dentistry and Endodontics
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• 제37권3호
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• pp.142-148
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• 2012

Objectives: We analyzed gene-expression profiles after 14 day odontogenic induction of human dental pulp cells (DPCs) using a DNA microarray and sought candidate genes possibly associated with mineralization. Materials and Methods: Induced human dental pulp cells were obtained by culturing DPCs in odontogenic induction medium (OM) for 14 day. Cells exposed to normal culture medium were used as controls. Total RNA was extracted from cells and analyzed by microarray analysis and the key results were confirmed selectively by reverse-transcriptase polymerase chain reaction (RT-PCR). We also performed a gene set enrichment analysis (GSEA) of the microarray data. Results: Six hundred and five genes among the 47,320 probes on the BeadChip differed by a factor of more than two-fold in the induced cells. Of these, 217 genes were upregulated, and 388 were down-regulated. GSEA revealed that in the induced cells, genes implicated in Apoptosis and Signaling by wingless MMTV integration (Wnt) were significantly upregulated. Conclusions: Genes implicated in Apoptosis and Signaling by Wnt are highly connected to the differentiation of dental pulp cells into odontoblast.

• International Journal of Oral Biology
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• 제37권4호
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• pp.167-173
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• 2012

This study investigated the genes involved in the differentiation of odontoblasts derived from human dental pulp stem cells (hDPSCs). hDPSCs isolated from human tooth pulp were validated by fluorescence activated cell sorting (FACS). After odontogenic induction, hDPSCs were analyzed investigated by Alizaline red-S staining, ALP assay, ALP staining and RT-PCR. Differential display-polymerase chain reaction (DD-PCR) was performed to screen differentially expressed genes involved in the differentiation of hDPSCs. By FACS analysis, the stem cell markers CD24 and CD44 were found to be highly expressed in hDPSCs. When hDPSCs were treated with agents such as ${\beta}$-glycerophosphate (${\beta}$-GP) and ascorbic acid (AA), nodule formation was exhibited within six weeks. The ALP activity of hDPSCs was found to elevate over time, with a detectable up-regulation at 14 days after odontogenic induction. RT-PCR analysis revealed that dentin sialophosphoprotein (DSPP) and osteocalcin (OC) expression had increased in a time-dependent manner in the induction culture. Through the use of DD-PCR, several genes were differentially detected following the odontogenic induction. These results suggest that these genes may possibly be linked to a variety of cellular process during odontogenesis. Furthermore, the characterization of these regulated genes during odontogenic induction will likely provide valuable new insights into the functions of odontoblasts.

• 대한소아치과학회지
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• 제46권2호
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• pp.219-225
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• 2019

이 연구의 목적은 과잉치 치수 유래 줄기세포의 계대 배양 속도에 대한 상아모세포 연관 유전자의 발현을 비교하는 것이다. 줄기세포는 다른 여러 형태의 세포로 분화할 수 있는 미 분화된 세포이다. 이는 환경이나 특정 자극에 의해 세포 분열이 일어나며 근육이나 골 같은 특정 장기의 조직으로 분화할 수 있다. 20명의 어린이에서 발거한 과잉치에서 과잉치 치수 유래 줄기세포가 얻어졌다. 10계대까지 배양하는 동안 가장 빠른 속도로 계대 배양된 세포와 가장 느린 속도로 계대 배양된 세포 각 3계대와 10계대 세포를 얻어 실험을 진행하였다. 각 세포는 분화제를 처리한 군과 처리하지 않은 군으로 나누었다. 이 실험에서 발현도를 살펴본 유전자는 Osteonectin (ONT), Osteocalcin (OCN), Alkaline Phosphatase (ALP), Dentin matrix acidic phosphoprotein 1 (DMP-1), Dentin sialophosphoprotein (DSPP)이다. 분화가 된 세포가 전반적으로 더 높은 유전자 발현도를 보였으며, 미분화 세포는 10계대에서, 분화된 세포는 3계대에서 더 높은 유전자 발현도를 보였다. 빠른 계대 배양 속도를 보인 세포가 OCN과 DSPP를 제외하고 상대적으로 더 낮은 유전자 발현도를 보였다.

• International Journal of Oral Biology
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• 제37권2호
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• pp.77-83
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• 2012

We investigated the pulpal response to direct pulp capping in rat molar teeth using mineral trioxide aggregate (MTA) and calcium hydroxide (CH). A palatal cavity was prepared in rat maxillary molar teeth. Either MTA or CH was placed on the exposed pulp and all cavities were restored with composite. Rats were sacrificed for histological evaluation after 12 hours and at 2, 7, 14 and 21 days. In both the MTA and CH groups, reparative dentin formation was clearly observed on histology after 14 days. The MTA-capped pulps were found to be mostly free from inflammation, and hard tissue of a tubular consistent barrier was observed. In contrast, in CH-capped teeth, excessive formation of reparative dentin toward residual pulp was evident. The pulpal cell response beneath the reparative dentin layer was examined by immunofluorescence using antibodies against DSP. After 2 days, a few DSP immunopositive cells, most of which showed a cuboidal shape, appeared beneath the predentin layer. At 7 days, DSP-immunopositive cells with columnar odontoblast-like cells were seen beneath the newly formed hard tissues. At 14 and 21 days, DSP was more abundant in the vicinity of the odontoblastic process along the dentinal tubules than in the mineralized reparative dentin. The CH group showed strong expression patterns in terms of DSP immunoreactivity. Our results thus indicate that MTA may be a more effective pulp capping material as it induces the differentiation of odontoblast-like cells and the formation of reparative dentin without the loss of residual pulp functions.

• 치위생과학회지
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• 제9권4호
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• pp.427-433
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• 2009

본 연구는 상아모세포의 분화와 상아질 형성과정에서 필수적인 인자로 알려진 NFI-C가 상아모세포 기질단백질의 발현에 미치는 영향을 알아보기 위하여, MDPC-23 상아모세포에 NFI-C 유전자를 과발현 시키거나 발현억제시킨 후 상아질 기질단백질 유전자들의 발현을 RT-PCR로 분석한 결과 다음과 같은 결론을 얻었다. 1. MDPC-23 세포에서 NFI-C mRNA는 NFI-C 과발현후에 현저히 증가하였으며, NFI-C 발현억제 후에는 감소하였다. 2. NFI-C가 과발현된 MDPC-23 세포는 NFI-C 단백질이 핵과 세포질에서 뚜렷이 관찰되었으나, NFI-C 발현이 억제된 MDPC-23 세포에서는 NFI-C 단백질의 발현이 대조군에 비하여 현저히 감소하였다. 3. NFI-C 발현이 억제된 MDPC-23 세포는 대조군에 비하여 I형 아교질, OC, 및 DSPP mRNA의 발현은 감소하였으나 BSP의 발현은 증가하였다. ALP와 DMP4의 발현은 NFI-C 발현억제 후에도 변화가 없었다. 4. NFI-C가 과발현된 MDPC-23 세포에서는 ALP와 DMP4 mRNA의 발현은 대조군에 비하여 증가하였으며 I형 아교질, OC, DSPP, 및 BSP의 발현은 감소하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제43권2호
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• pp.63-69
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• 2017

Nuclear factor I-C (NFI-C) plays a pivotal role in various cellular processes such as odontoblast and osteoblast differentiation. Nfic-deficient mice showed abnormal tooth and bone formation. The transplantation of Nfic-expressing mouse bone marrow stromal cells rescued the impaired bone formation in $Nfic^{-/-}$ mice. Studies suggest that NFI-C regulate osteogenesis and dentinogenesis in concert with several factors including transforming growth factor-${\beta}1$, $Kr{\ddot{u}}ppel$-like factor 4, and ${\beta}$-catenin. This review will focus on the function of NFI-C during tooth and bone formation and on the relevant pathways that involve NFI-C.

• 대한소아치과학회지
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• 제48권3호
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• pp.291-301
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• 2021

이 연구의 목적은 발거 된 매복 상악 과잉치에서 얻은 치수유래 줄기세포의 초기 계대와 후기 계대의 상아질모세포 유전자의 특성을 알아보는 것이다. 전신 의과 병력이 없는 6 - 9세 사이의 남녀아이 12명에게서 서면동의를 얻고 모두 상악에 위치한 과잉치를 발거하여 당일 발거된 과잉치의 치수세포를 채취하였다. 12개의 세포를 각각 3계대와 10계대에서 골형성 유도 분화제를 처리한 군과 처리하지 않은 군을 나누어 실시간 중합효소 연쇄반응을 시행하여 상아질모세포의 특성을 알아보았다. 사용된 유전자는 osteonectin (ONT), alkaline phosphatase (ALP), osteocalcin (OCN), dentin matrix protein 1 (DMP-1), 그리고 dentin sialophosphoprotein (DSPP)였다. 유전자 발현양은, 분화제를 처리하지 않은 군 3계대에서는 ONT, ALP, OCN, DMP-1, DSPP순서로 많이 발현하였다. 분화제를 처리하지 않은 군 10계대에서는 ONT, DMP-1, OCN, ALP, DSPP순으로 ONT, OCN, DSPP의 순서에는 변화가 없지만 ALP, DMP-1의 순서는 서로 바뀌었다. 이상의 결과를 종합해 볼 때, ALP와 DMP-1은 3계대와 10계대 세포의 분화를 위한 중요한 표지자로 사용될 수 있다. 과잉치 치수유래 줄기세포는 상아질모세포의 특성을 가지며, 또한 과잉치가 어린 나이에 발거되고 10계대까지 소요되는 시간이 적게 걸린다는 것을 고려하면, 과잉치는 치아 유래 줄기세포의 공여부로서 훌륭한 활용가능성이 있음을 확인하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권5호
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• pp.415-420
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• 2011

Purpose: Calcium phosphate cement (CPC) is one of many useful materials for restoring tooth defects, periodontium and maxillofacial area. Chitosan is a biodegradable material that has been shown to promote the growth and differentiation of osteoblasts in culture. This study examined the interaction between odontoblasts and bio-calcium phosphate cement reinforced with chitosan. Materials and Methods: $5{\times}10^3$ odontoblastic cells were seeded into each well. Various concentrations of bio-calcium phosphate cement reinforced with chitosan (10, 20, 50, 100, 200, 500 ${\mu}g$/ml, 1, 2, 4 mg/ml) were diluted and added to the wells. The well was incubated for 24 h, 48 h and 72 h. After incubation, the number of cells was assessed to determine the cell viability. A cytokinesis-block micronucleus assay and chromosomal aberration test were carried out to estimate the extent of chromosomal abnormalities. Microscopic photographs and RT-PCR were performed to examine the adhesion potential of bio-calcium phosphate cement reinforced with chitosan. Results: Bio-CPC-reinforced chitosan did not show significant cytotoxicity. The number of damaged chromosomes in the cells treated with Bio-CPC-reinforced chitosan was similar to that in the control cells. There was no significant increase in the number of chromosomal aberrations in the Bio-CPC reinforced chitosan exposed cells. Microscopic photographs and RT-PCR confirmed the adhesive potential of bio-CPC reinforced chitosan to odontoblasts. Conclusion: Bio-CPC-reinforced chitosan did not affect the odontoblastic cell viability, and had no significant cytotoxic effect. Bio-CPC-reinforced chitosan showed adhesive potential to odontoblasts. These results are expected form the basis of future studies on the effectiveness of dental restorative materials in Bio-CPC reinforced with chitosan.