• 대한소아치과학회지
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• 제45권2호
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• pp.242-249
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• 2018

이 연구의 목적은 정량적 실시간 중합효소 연쇄 반응법을 이용하여 발거된 과잉치 치수 및 치주인대 줄기세포의 유전자 발현을 비교하는 것이다. 전신병력이 없는 만 6세 남아 2명의 상악 전치부에 매복된 과잉치를 발거하였다. 같은 날 치수 및 치주인대 세포를 채취하였고, 3계대까지 계대배양하였다. 분석을 위해 상아질모세포 특이 유전자인 Alkaline phosphatase (ALP), Dentin Matrix Protein 1 (DMP-1), Dentin sialophosphoprotein (DSPP), Osteocalcin (OCN) 그리고 Osteonectin (ONT)을 사용했고, glyceraldehyde 3-phosphate dehydrogenase (GAPDH)을 대조군으로 설정했다. 과잉치 치수 세포에서는 ONT, OCN, ALP, DMP-1, DSPP 순서로 발현량이 많았고, 치주인대 세포에서는 DMP-1과 DSPP의 순서만 바뀌었다. 치주인대 세포보다 치수 세포에서 모든 유전자의 발현량이 많았다. 이러한 상아질모세포의 특성을 고려해 보았을 때, 다른 조직으로의 분화 가능성이 있는 과잉치 줄기세포는 유용한 공여부로서 그 잠재력이 있음을 알 수 있었다.

• International Journal of Oral Biology
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• 제40권1호
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• pp.1-9
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• 2015

Osteocalcin (OC) is the most abundant noncollagenous protein of extracellular matrix in the bone. In an OC deficient mouse, bone formation rates are increased in cancellous and cortical bones. OC is known as a negative regulator of mineral apposition. OC is also expressed in the tooth of the rat, bovine, and human. However, little is known about OC during tooth development in Xenopus. The purpose of this study is to compare the expression of OC with mineralization in the developing tooth of Xenopus, by using von Kossa staining and in situ hybridization. At stage 56, the developmental stage of tooth germ corresponds to the cap stage, and an acellular zone was apparent between the dental papilla and the enamel organ. From stage 57, calcium deposition was revealed by von Kossa staining prior to OC expression, and the differentiated odontoblasts forming predentin were located at adjoining predentin. At stage 58, OC transcripts were detected in the differentiated odontoblasts. At stage 66, OC mRNA was expressed in the odontoblasts, which was aligned in a single layer at the periphery of the pulp. These findings suggest that OC may play a role in mineralization and odontogenesis of tooth development in Xenopus.

• Imaging Science in Dentistry
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• 제30권3호
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• pp.169-181
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• 2000

Purpose: To investigate the expression of bone morphogenetic protein (BMP)-2/4 during eary tooth development after irradiation and calcium-deficient diet. Materials and Methods: The pregnant three-week-old Sprague-Dawley rats were used for the study. The control group was non-irradiation/normal diet group (Group 1), and the experimental groups were irradiation/normal diet group (Group 2) and irradiation/calcium-deficient diet group (Group 3). The abdomen of the rats at the 9th day of pregnancy were irradiated with single dose of 350 cGy. The rat pups were sacrificed at embryonic 18 days, 3 days and 14 days after delivery and the maxillae tooth germs were taken. The tissue sections of specimen were stained immunohisto-chemically with anti-BMP-2/4 antibody. Results: At embryo-18 days, immunoreacivity for BMP-2/4 of the Group 1 was modetate in stratum intermedium of dental organ and weak in dental papilla and dental follicle, but that of Group 2 was weak in cell layer of dental organ, and no immunoreacivity was shown in dental papilla and dental follice of Group 2 and in all tissue components of the Group 3. At postnatal-3 days, immunoreacivity for BMP-2/4 of the Group 1 was strong in cell layer of dental organ, odontoblasts and developing alveolar bone, but that of Group of 2 and Group 3 was weak in odontoblasts and developing alveolar bone. At postnatal-14 days, immunoreacivity for BMP-2/4 of the Group 1 was strong in newly formed cementum, alveolar bone and odontoblasts, but that of Group 2 was weaker than that of Group 1. In the Group 3, tooth forming cell layer showed weak immunoreactivity, but other cell layers showed no immunoreactivity. Couclusion : The expression of bone morphogenetic protein (BMP)-2/4 during early tooth development was disturbed after irradiation and calcium-deficient diet.

• Restorative Dentistry and Endodontics
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• 제29권4호
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• pp.399-408
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• 2004

Odontoblasts are responsible for the formation and maintenance of dentin. They are known to synthesize unique gene products including dentin sialophosphoprotein (DSPP). Another unique genes of the cells remain unclear. OD314 was isolated from the odontoblasts/pulp cells of rats and partially characterized as an odontoblast-enriched gene (Dey et al., 2001). This study aimed to elucidate the biological function of OD314, relating to odontoblast differentiation and dentinogenesis. After determining the open reading frame (ORP) of OD314 by transient transfection analysis using green fluorescent protein (GPP) expression vector, mRNA in-situ hybridization, immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR) and western analysis were performed. The results were as follows: 1. In in-situ hybridization, OD314 mRNAs were expressed in odontoblasts of developing coronal and root pulp. 2. OD314 was a novel protein encoding 154 amino acids, and the protein was mainly expressed in cytoplasm by transient transfection analysis. 3. Mineralized nodules were associated with multilayer cell nodules in the culture of human dental pulp cells and first detected from day 21 using alizarin-red S staining. 4. In RT-PCR analysis, OD314, osteocalcin (OC) and DSPP strongly expressed throughout 28 days of culture. Whereas, osteonectin (ON) mRNA expression stayed low up to day 14, and then gradually decreased from day 21. 5. Western blots showed an approximately 17 kDa band. OD314 protein was expressed from the start of culture and then increased greatly from day 21. In conclusion, OD314 is considered as an odontoblast-enriched gene and may play important roles in odontoblast differentiation and dentin mineralization.

• 대한치과보철학회지
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• 제24권1호
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• pp.125-138
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• 1986

It is considered that etching solution or material itself of phosphoric ester cement will induce not a little pulpal irritation, if applied directly onto unsealed dentinal tubules. This study was designed to confirm above consideration by comparing two different conditions between $Ca(OH)_2$-based and non-$Ca(OH)_2$-based group. Posterior teeth of 15 male dogs were selected for this experiment. One experimental group was filled with cement after $Ca(OH)_2$-basing and enamel-etching, the other experimental group after enamel etching without $Ca(OH)_2$-basing. And both of two experimental groups were observed at 2 hours, 15 hours, 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks after filling. The findings reached to the following conclusions histologically. 1. In both groups, the damaged odontoblasts were atrophied and eventually disappeared. 2. In non-based group at early stage, odontoblasts were severely atrophied and defective areas were appeared between odontoblast cell layers. However, in based group, the odontoblasts were arranged slight irregularly. 3. In non-based group, a small number of undifferentiated cells below the odontoblast cell layers started to appear at 1 week after filling. However, in based group, the undifferentiated cells were appeared at 15 hours after filling. 4. In non-based group, formation of reparative dentin was not begun until late stage of experiment. However, in based group, formation of reparative dentin matrix was begun at 2 weeks after filling and very thickened reparative dentin was formed at 6 weeks after filling. 5. In odontoblast cell layers of both groups, dilated capillaries were observed. 6. Argyrophilic fibers were reticularly condensed in zone of Weil, and they were connected to the pulp tissue and dentin.

• International Journal of Oral Biology
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• 제36권4호
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• pp.195-201
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• 2011

Matrix metalloproteinases (MMPs) have been implicated in tissue development and re-modeling. Dynamic morphological changes of tooth germs reflect involvement of these enzymes during odontogenesis. The present study was performed to investigate expression and localization of MMP-2 and MMP-9, which have been known to have type IV collagenase activities, in rat tooth germs at different developmental stages. MMP-2 expression was increased gradually in the tooth germs from cap to crown staged germs at both transcription and translation levels. The localization of this molecule was detected in secretory ameloblasts and preameloblasts. The strong immunoreactivities were occasionally seen along the basement membrane between ameloblasts (or preameloblasts) and odontoblasts (preodontoblasts). However, weak reactivity was detected in odontoblasts and reduced enamel epithelium. The level of MMP-9 expression in the tooth germs was higher in cap stage than in crown staged germs at both transcription and translation levels. They were strongly expressed in both ameloblasts and odontoblasts. Even though reduced enamel epithelium after enamel formation and inner enamel epithelium at the cap stage exhibited weak reactivity, strong reactivity was detected in dental follicles and perifollicular tissues surrounding cap staged germs. These results suggested that MMP-2 may involve degradation of the basement membrane during hard tissue formation, whereas MMP-9 might be involved in remodeling of follicular tissues.

• 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.

• Applied Microscopy
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• 제36권1호
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• pp.17-23
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• 2006

음용불소가 흰쥐태아의 상아모세포에 간접적으로 미치는 영향과 농도를 확인하기 위해 임신한 흰쥐에 100, 200, 300ppm의 불소가 함유된 음용수를 임신기간 동안 투여하였다. 대조군과 비교하였을 때, 농도에 의존적으로 상아모세포의 미세구조적 변화를 관찰 할 수 있었다. 조면소포체로 부터 리보솜의 탈락과 붕괴, 미토콘드리아의 팽창, 그리고 조면소포체와 미토콘드리아의 변성. 음용 불소의 농도에 따른 미세구조적인 변화로부터 100, 200ppm에서는 가역적인 그리고 300ppm에서는 비가역적인 손상이 유도되는 것을 확인하였다. 또한, 이러한 결과로 미루어 200ppm미만의 농도가 발생중인 흰쥐태아에 영향을 주지 않는 것을 알 수 있다.

• The Korean Journal of Physiology and Pharmacology
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• 제26권1호
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• pp.37-45
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• 2022

The aim of the present study was to investigate the physiological role of nicotinamide phosphoribosyltransferase (NAMPT) associated with odontogenic differentiation during tooth development in mice. Mouse dental papilla cell-23 (MDPC-23) cells cultured in differentiation media were stimulated with the specific NAMPT inhibitor, FK866, and Visfatin (NAMPT) for up to 10 days. The cells were evaluated after 0, 4, 7, and 10 days. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The mineralization assay was performed by staining MDPC-23 cells with Alizarin Red S solution. After cultivation, MDPC-23 cells were harvested for quantitative PCR or Western blotting. Analysis of variance was performed using StatView 5.0 software (SAS Institute Inc., Cary, NC, USA). Statistical significance was set at p < 0.05. The expression of NAMPT increased during the differentiation of murine odontoblast-like MDPC-23 cells. Furthermore, the up-regulation of NAMPT promoted odontogenic differentiation and accelerated mineralization through an increase in representative odontoblastic biomarkers, such as dentin sialophosphoprotein, dentin matrix protein-1, and alkaline phosphatase in MDPC-23 cells. However, treatment of the cells with the NAMPT inhibitor, FK866, attenuated odontogenic differentiation, as evidenced by the suppression of odontoblastic biomarkers. These data indicate that NAMPT regulated odontoblastic differentiation through the regulation of odontoblastic biomarkers. The increase in NAMPT expression in odontoblasts was closely related to the formation of the extracellular matrix and dentin via the Runx signaling pathway. Therefore, these data suggest that NAMPT is a critical regulator of odontoblast differentiation during tooth development.

• Applied Microscopy
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• 제43권1호
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• pp.27-33
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• 2013

Inflammatory cells express the inflammatory cytokines and growth factors induced by lipopolysaccharide (LPS). Odontoblasts are located at the pulp-dentin interface and extend their cell processes far into the dentin where they are the first cells to encounter microorganisms or their products. Therefore, this study examined the expression of some growth factors related to the signal pathway, such as growth factor receptor binding protein 2 (Grb2)-Ras in odontoblast-like dental pulp cells, after a treatment with LPS. After 60 minutes, the mRNA and protein expression levels of Grb2 and Ras were higher in the LPS-treated cells than in the control cells. The level of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) mRNA expression was increased significantly to a level similar to that of Grb2 and Ras at 60 minutes. The platelet-derived growth factor-AA (PDGF-AA) mRNA level was expressed strongly in the odontoblast like dental pulp cells without an association with LPS stimulation. Scanning electron microscopy revealed many extensions of the cytoplasmic processes and the number of processes increased gradually at 30, 60 and 90 minutes after LPS stimulation. From these results VEGF and bFGF expression might be induced through the Grb2-Ras signal transduction pathway in LPS treated odontoblasts.