• Journal of dental hygiene science
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• v.10 no.4
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• pp.227-231
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• 2010

The purpose of this study was to examine the MAPK signaling pathways involved in regulation of HO-1 and the odontoblast differentiation markers during the odontoblastic differentiation for HDPCs. We evaluated cell growth by MTT assay and differentiation marker mRNA expression by RT-PCR. When the cells were treated with p38 inhibitor (SB203580, $10{\mu}M$), JNK inhibitor (SP600125, $10{\mu}M$), and ERK inhibitor (PD98059, $20{\mu}M$) for 7 days, cell growth and expression of HO-1 and differentiation makers were significantly decreased in HDPCs. Our results suggest that odontoblastic differentiation is positively regulated by HO-1 induction in HDPCs via ERK, JNK, and p38 signaling pathways. Thus, pharmacological HO-1 induction might represent a potent therapeutic approach for pulp capping and the regeneration of HDPCs.

• International Journal of Oral Biology
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• v.38 no.4
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• pp.161-167
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• 2013

Human dental pulp stem cells (DPSCs) are multi-potent mesenchymal stem cells that have several differentiation potentials. An understanding of thetissues that differentiate from these cells can provide insights for future regenerative therapeutics and tissue engineering strategies. The mesiodens is the most frequent form of supernumerary tooth from which DPSCs can differentiate into several lineages similar to cells from normal deciduous teeth. Recently, it has been shown that nanoscale structures can affect stem cell differentiation. In our presentstudy, we investigated the effects of a 250-nm nanoscale ridge/groove pattern array on the osteogenic and adipogenic differentiation of dental pulp cells from mesiodenscontaining human DPSCs. To this end, the expression of lineage specific markers after differentiation induction was analyzed by lineage specific staining and RT-PCR. The nanoscale pattern arrayed surface showed apositive effect on the adipogenic differentiation of DPSCs. There was no difference between nanoscale pattern arrayed surface and conventional surface groups onosteogenic differentiation. In conclusion, the nanoscale ridge/groove pattern arrayed surface can be used to enhance the adipogenic differentiation of DPSCs derived from mesiodens. This finding provides an improved understanding of the effects of topography on cell differentiation as well as the potential use of supernumerary tooth in regenerative dental medicine.

• International Journal of Oral Biology
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• v.31 no.3
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• pp.73-79
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• 2006

Tissue stem cells are used for the regenerative medicine. In previous study we observed hard tissue formation of human dental pulp-derived cells using alginate scaffold. In this study, we explore the ability to differentiate of the 13th passage cells with glycerol 2-phosphate disodium salt hydrate (${\beta}-GP$) which accelerate calcification. Reverse transcriptase Polymerase Chain Reaction (RT-PCR), transplants using alginate scaffold and histological examination were performed. We observed the expression of DSPP mRNA on day 10 cultured cells with ${\beta}-GP$. In conclusion, the 13th passage cells still have an ability to differentiate into odontoblast-like cells and alginate supports the differentiation of cultured cells in the transplants.

• International Journal of Oral Biology
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• v.47 no.4
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• pp.55-62
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• 2022

Bioactive flavonoids have been shown to improve the biological activity of stem cells derived from different sources in tissue regeneration. The goal of this study was to see how naringin, a natural flavonoid discovered in citrus fruits, affected the biological properties of human dental pulp stem cells (HDPSCs). In this study, we found that naringin increases the migratory ability of HDPSCs. Naringin increased matrix metalloproteinase-2 (MMP-2) and C-X-C chemokine receptor type 4 (CXCR4) mRNA and protein expression in HDPSCs. ARP100, a selective MMP-2 inhibitor, and AMD3100, a CXCR4 antagonist, both inhibited the naringin-induced migration of HDPSCs. Furthermore, naringin increased osteogenic differentiation of HDPSCs and the expression of the osteogenic-related marker, alkaline phosphatase in HDPSCs. Taken together, our findings suggest that naringin may be beneficial on dental tissue or bone regeneration by increasing the biological activities of HDPSCs.

• BMB Reports
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• v.55 no.7
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• pp.336-341
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• 2022

Narrowing of arteries supplying blood to the limbs provokes critical hindlimb ischemia (CLI). Although CLI results in irreversible sequelae, such as amputation, few therapeutic options induce the formation of new functional blood vessels. Based on the proangiogenic potentials of stem cells, in this study, it was examined whether a combination of dental pulp stem cells (DPSCs) and human umbilical vein endothelial cells (HUVECs) could result in enhanced therapeutic effects of stem cells for CLI compared with those of DPSCs or HUVECs alone. The DPSCs+ HUVECs combination therapy resulted in significantly higher blood flow and lower ischemia damage than DPSCs or HUVECs alone. The improved therapeutic effects in the DPSCs+ HUVECs group were accompanied by a significantly higher number of microvessels in the ischemic tissue than in the other groups. In vitro proliferation and tube formation assay showed that VEGF in the conditioned media of DPSCs induced proliferation and vessel-like tube formation of HUVECs. Altogether, our results demonstrated that the combination of DPSCs and HUVECs had significantly better therapeutic effects on CLI via VEGF-mediated crosstalk. This combinational strategy could be used to develop novel clinical protocols for CLI proangiogenic regenerative treatments.

• Restorative Dentistry and Endodontics
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• v.45 no.1
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• pp.3.1-3.10
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• 2020

Objectives: This study investigated the indirect effect of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA), as 2 calcium silicate-based hydraulic cements, on human dental pulp stem cells (hDPSCs) through different dentin thicknesses. Materials and Methods: Two-chamber setups were designed to simulate indirect pulp capping (IPC). Human molars were sectioned to obtain 0.1-, 0.3-, and 0.5-mm-thick dentin discs, which were placed between the 2 chambers to simulate an IPC procedure. Then, MTA and CEM were applied on one side of the discs, while hDPSCs were cultured on the other side. After 2 weeks of incubation, the cells were removed, and cell proliferation, morphology, and attachment to the discs were evaluated under scanning electron microscopy (SEM). Energy-dispersive X-ray (EDXA) spectroscopy was performed for elemental analysis. Alkaline phosphatase (ALP) activity was assessed quantitatively. The data were analyzed using the Kruskal-Wallis and Mann-Whitney tests. Results: SEM micrographs revealed elongated cells, collagen fibers, and calcified nucleations in all samples. EDXA verified that the calcified nucleations consisted of calcium phosphate. The largest calcifications were seen in the 0.1-mm-thick dentin subgroups. There was no significant difference in ALP activity across the CEM subgroups; however, ALP activity was significantly lower in the 0.1-mm-thick dentin subgroup than in the other MTA subgroups (p < 0.05). Conclusions: The employed capping biomaterials exerted biological activity on hDPSCs, as shown by cell proliferation, morphology, and attachment and calcific precipitations, through 0.1- to 0.5-mm-thick layers of dentin. In IPC, the bioactivity of these endodontic biomaterials is probably beneficial.

• International Journal of Oral Biology
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• v.37 no.4
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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.

• International Journal of Oral Biology
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• v.42 no.3
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• pp.91-97
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• 2017

Although anti-aging activities of melatonin, a hormone secreted by the pineal gland, have been reported in senescence-accelerated mouse models and several types of cells, its impact and mechanism on the senescence of human dental pulp cells (HDPCs) remains unknown. In this study, we examined the impact of melatonin on cellular premature senescence of HDPCs. Here, we found that melatonin markedly inhibited senescent characteristics of HDPCs after exposure to hydrogen peroxide ($H_2O_2$), including the increase in senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal)-positive HDPCs and the upregulation of p21 protein, an indicator for senescence. In addition, as melatonin attenuated $H_2O_2$-stimulated phosphorylation of c-Jun N-terminal kinase (JNK), while selective inhibition of JNK activity with SP600125 significantly attenuated $H_2O_2$-induced increase in SA-beta-gal activity. Results reveal that melatonin antagonizes premature senescence of HDPCs via JNK pathway. Thus, melatonin may have therapeutic potential to prevent stress-induced premature senescence, possibly correlated with development of dental pulp diseases, and to maintain oral health across the life span.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.4
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• pp.173-180
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• 2014

Objectives: The purpose of this study was to investigate the neurogenic differentiation of human dental pulp stem cells (DPSCs), periodontal ligament stem cells (PDLSCs), and stem cells from apical papilla (SCAP). Materials and Methods: After induction of neurogenic differentiation using commercial differentiation medium, expression levels of neural markers, microtubule-associated protein 2 (MAP2), class III ${\beta}$-tubulin, and glial fibrillary acidic protein (GFAP) were identified using reverse transcriptase polymerase chain reaction (PCR), real-time PCR, and immunocytochemistry. Results: The induced cells showed neuron-like morphologies, similar to axons, dendrites, and perikaryons, which are composed of neurons in DPSCs, PDLSCs, and SCAP. The mRNA levels of neuronal markers tended to increase in differentiated cells. The expression of MAP2 and ${\beta}$-tubulin III also increased at the protein level in differentiation groups, even though GFAP was not detected via immunocytochemistry. Conclusion: Human dental stem cells including DPSCs, PDLSCs, and SCAP may have neurogenic differentiation capability in vitro. The presented data support the use of human dental stem cells as a possible alternative source of stem cells for therapeutic utility in the treatment of neurological diseases.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.3
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• pp.337-342
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• 2019

The aim of this study was to analyze cells from human dental pulp tissue of impacted supernumerary teeth as stem cells with flow cytometry. Human dental pulp cells from 15 supernumerary teeth were identified their characteristics as stem cells by expression of mesenchymal stem cell markers through flow cytometry analysis at passage 3 and passage 10. Cluster of differentiation (CD) 73, CD 90, CD 34, CD 45 and STRO-1 cell surface markers were used to figure out characteristics of dental pulp stem cells from supernumerary teeth. At passage 3, the cell population showed positive expression of CD 73, CD90 and STRO-1, lacked expression of CD 34 and CD 45. At passage 10, CD 73, CD 90 and STRO-1 showed positive expression while CD 34 and CD 45 showed negative expression. This study indicated that dental pulp stem cells of supernumerary teeth had the properties of mesenchymal stem cells at both early and late passage. Impacted supernumerary teeth could be considered as a noble source of stem cells because of rapid growth and maintaining characteristics of stem cells until late passage.