The mesenchymal stem cells (MSCs) that reside in dental tissues hold a great potential for future applications in regenerative dentistry. In this study, we used human dental pulp cells, isolated from the molars (DPCs), in order to establish the organoid culture. DPCs were established after growing pulp cells in an MSC expansion media (MSC-EM). DPCs were subjected to organoid growth media (OGM) in comparison with human dental pulp stem cells (DPSCs). Inside the extracellular matrix in the OGM, the DPCs and DPSCs readily formed vessel-like structures, which were not observed in the MSC-EM. Immunocytochemistry analysis and flow cytometry analysis showed the elevated expression of CD31 in the DPCs and DPSCs cultured in the OGM. These results suggest endothelial cell-prone differentiation of the DPCs and DPSCs in organoid culture condition.

본 연구에서는 전문대학생들의 자아존중감, 자아분화수준, 스마트폰 중독의 관계를 파악하고자 하였다. 전문대학생들의 자아존중감, 자아분화수준이 스마트폰 중독에 미치는 영향을 밝히는데 목적을 두었다. 수집된 285부의 자료는 SPSS WIN 22.0 프로그램을 사용하여 분석하였다. 첫째, 전문대학생의 자아존중감, 자아분화수준, 스마트폰 중독의 일반적 특성에 대해 살펴보았다. 둘째, 전문대학생의 자아존중감, 자아분화수준, 자아존중감, 스마트폰 중독의 관계를 알아보기 위하여 상관관계분석을 실시하였다. 셋째, 스마트폰 중독에 영향을 미치는 자아존중감, 자아분화 수준의 영향력을 알아보기 위하여 중다회귀분석을 실시하였다. 연구결과, 첫째 전문대학생들의 자아존중감이 낮아질수록 전문대학생들의 스마트폰 중독 정도 가 높아진다는 것을 알 수 있었다. 둘째, 전문대학생들의 자아분화수준이 낮을수록 스마트폰 중독 정도가 높아진다는 것을 알 수 있다. 본 연구를 통하여 스마트폰으로 야기되는 문제들을 개선하고 건강하고 바람직한 스마트폰 사용 습관을 위한 프로그램의 기반이 되고자 한다.

The proliferation of information technologies made it possible to produce information products of different versions at much lower cost comparing to traditional physical products. Thus it is common for information product manufacturers to consider vertically differentiated product line for more profit through improved market coverage. Another salient characteristic of most information product is network externality. Existing researches dealing with vertical differentiation and network externality usually assumed oligopolistic market where vertically differentiated products are provided by competing companies, respectively. Moreover, they analyzed the essentially dynamic characteristic of network externality statically. In this study, different from the previous researches, the vertical differentiation strategy of a monopolistic company under network externality is dynamically analyzed. We used a two-period model to accommodate the dynamic feature of network externality. Based on the two-period model, the profit maximizing solutions are analyzed. The results showed that a monopolistic company has no incentive to differentiate products vertically when the network externality is absent. On the contrary, when the network externality exists, the monopolistic company can derive more profit by vertically differentiating the product line. It is also shown that, for more profit, the monopolistic company should keep the quality difference between the high quality product and the low quality product as greater as possible.

한자 ‘道’와 ‘教’는 동의어에 속하지 않지만, ‘종교’의 의미범주를 가진 형태소로 활용되는 경우에는 동일하게 이해하는 경향이 많다. 하지만 본문은 종교의미의 ‘道’와 ‘教’가 형태소로서 어휘를 구성하면서 나타나는 의미항목의 차이점에 대해, 다양한 어휘자료를 분석하여 고찰해 보고자 하였다. 먼저 ‘道’는 본래 원형의미가 가지고 있던 추상적인 원리가 여전히 작용함으로써, ‘종교’의 미를 나타낼 때에도 여전히 구체적인 행위나 실천으로 전이되지 않았다. 이와 반대로, ‘教’ 또한 비록 ‘教理’나 ‘教法’ 등으로 표현될 때는 ‘道’의 의미범주에 근접하고 있지만, 여전히 추상적 원리에는 접근하지 못하고 구체적인 행위와 연관되어 나타나고 있었다. 따라서 비록 일상적인 종교 활동에서 ‘宣教’와 ‘传道’가 혼용되어나 반대로 이해하는 사람들도 있었지만, 만약 원형의미를 근거로 해석을 할 경우에는 ‘传道’는 교리의 전달에 초점이 있으며, ‘宣教’는 교세의 확장과 관련된 교도(教徒)들의 구체적인 활동으로 구별하여 이해되어야 할 것으로 보인다.

본 연구는 자색옥수수 색소 1호 포엽과 속대 추출물의 항비만 활성을 검정하고자 지방분해효소 저해활성을 평가 하고 3T3-L1 지방전구세포에서 지방분화억제 효과를 검정하고자 수행되었다. Pancreatic lipase 저해 활성 결과, 색소 1호 포엽 및 속대 추출물의 100, 500, 1,000 μg/mL 농 도처리구에서 양성대조군인 orlistat 보다 높은 저해 활성을 나타내었다. 3T3-L1 지방전구세포를 배양하여 색소 1 호 포엽 및 속대 추출물의 세포독성 평가를 수행한 결과, 추출물은 모든 처리농도에서 세포 생존율에 영향을 미치 지 않은 것으로 확인되었다. 분화된 3T3-L1 지방전구세포 에서 색소 1호 포엽과 속대 추출물을 처리하지 않고 분화 시킨 대조군은 lipid droplet의 형성이 활발하게 유발되었으나 색소 1호 포엽 및 속대 추출물의 처리에 의해 농도 의존적으로 lipid droplet의 형성이 억제되는 것으로 나타났다. Real-time PCR과 Western blot을 실시하여 PPARγ와 C/EBPα 유전자 및 단백질 발현량을 측정한 결과, 추출물을 처리하지 않고 분화시킨 대조군에서는 PPARγ와 C/ EBPα의 유전자 및 단백질 발현이 증가하였으며, 추출물 처리에 의해 PPARγ와 C/EBPα의 유전자 및 단백질 발현이 유의적으로 감소하였다. 본 연구 결과는 색소 1호 포엽 및 속대 추출물이 pancreatic lipase 활성 및 지방전구 세포의 분화를 억제시킴으로써 항비만 활성 기능성 물질 로의 활용 가능성이 높음을 시사한다.

Cluster of differentiation (CD) 24 or heat stable antigen 24 (HSA) molecule is a mucin-type glycoprotein attached to the cell surface by glycosylphosphatidylinositol (GPI)-anchor, promoting adhesive interactions between cells or in extracellular matrix. The aim of this study was to determine the not yet fully identified porcine CD24 gene and protein structure using computational analysis and to validate variants reported in exons of CD24 gene using direct sequencing. A total of 59 samples belonging to Yorkshire, Landrace, Berkshire, Jeju black pig and wild boar were used in the study. Human CD24 mRNA sequences were used as a reference and subjected to BLAST searches to retrieve the orthologous expressed sequence tags (ESTs) or cDNA sequences against NCBI and Ensemble databases. Assembled ESTs and retrieved cDNA sequences for the porcine CD24 gene were used for specific BLAST search to determine its genomic structure. We found porcine CD24 gene to consist of two exons and a relatively long intron. Second exon of porcine CD24 gene had a long 3’ untranslated region (UTR) and was very similar to that of human, mouse, rat, and sheep. The sequence homology of porcine CD24 protein was 65.38-84.62%, when analyzed with amino acid sequences of rat, mouse, human, cattle, and sheep CD24 protein. N-terminal signal sequence, O-glycosylation sites and GPI-anchoring signal sites were also predicted in pig, which showed these motifs to be evolutionary conserved across the species. Variant analysis in exonic regions of porcine CD24 among the multiple breeds showed that only second exon contained eight SNPs and three insertions in a 3’ UTR. Taken together, this study reports putative porcine CD24 gene and its protein structure using in silico approaches, which will be helpful for any further functional studies.

Osteoporosis is a metabolic bone disease that is characterized by low bone mass resulting from an increase in bone resorption relative to bone formation. The most current therapies for osteoporosis have focused on inhibiting bone resorption by osteoclasts. The purpose of this study is to develop new anabolic agents for treatment of osteoporosis that have fewer risks compared to conventional therapies. We searched the natural products that were derived from the traditional Asian medicines which have been used for treatment of bone related diseases. Icaritin is a flavonoid glycoside derived from the herb Epimedium which has beneficial effects on bone formation. To determine the effect of icaritin on bone formation, we examined the effect of icaritin on MC3T3-E1 cell proliferation and differentiation. For determining the effects of icaritin on proliferation, we performed the MTT assay using MC3T3-E1 cells. To evaluate whether icaritin could promote the osteogenic differentiation of MC3T3-E1 cells, alkaline phosphatase (ALP) activity and mRNA expressions of Runx2, osteocalcin (OCN), RANKL, and osteoprotegerin (OPG) were determined. Icaritin increased MC3T3-E1 cell proliferation. Icaritin increased the ALP activity of MC3T3-E1 cells on 72 hour culture in osteogenic media. mRNA expression of Runx2 was increased after 24 hour culture with icaritin. mRNA expression of osteocalcin was increased after 72 hour culture with icaritin. In addition, icaritin increased the mRNA expressions of OPG and RANKL. However, icaritin increased the mRNA expression of OPG much more than that of RANKL, and then, it increased the OPG/RANKL ratio. These results suggest that icaritin promotes osteogenic differentiation of osteoblasts and decreases osteoclast formation regulated by osteoblasts.

In this study, we investigated the effect of bisphosphonate on the osteoblastic differentiation of human dental stem cells (hDPSCs). In the first experiment, we evaluated the effect of bisphosphonate on the differentiation of hDPSCs into osteoblasts by alkaline phosphatase staining after culturing hDPSCs. As a result, on day 13, the osteogenic differentiation of hDPSC was suppressed at 5 μM in clodronate and 2 μM in zolendronate. In NBP, osteogenic differentiation is more suppressed. In second experiment, cytotoxicity and proliferation test, the cell proliferation (examined by MTT assay) was more suppressed as the concentrations of zolendronate were larger than those of alendronate and clodronate. Western blotting, a third experiment, was found that AKT phosphorylation was inhibited in cell signaling proteins involved in cell proliferation inhibition and death by bisphosphonate concentration. In human dental stem cells, bisphosphonates inhibit osteoblast differentiation, and this phenomenon is clearly observed in NBPs (zolendronate), and it has been found that it is related to AKT phosphorylation of cell signaling proteins.

The estrogen-mediated effect of mesenchymal stem cells (MSCs) is a highly critical factor for the clinical application of MSCs. However, the present study is conducted on MSCs derived from adult donors, which have different physiological status with steroid hormonal changes. Therefore, we explores the important role of 17β-estradiol (E2) in MSCs derived from female and male newborn piglets (NF- and NM-pBMSCs), which are non-sexually matured donors with steroid hormones. The results revealed that in vitro treatment of MSCs with E2 improved cell proliferation, but the rates varied according to the gender of the newborn donors. Following in vitro treatment of newborn MSCs with E2, mRNA levels of Oct3/4 and Sox2 increased in both genders of MSCs and they may be correlated with both estrogen receptor α (ERα) and ERβ in NF-pBMSCs, but NM-pBMSCs were only correlated with ERα. Moreover, E2-treated NF-pBMSCs decreased in β-galactosidase activity but no influence on NM-pBMSCs. In E2-mediated differentiation capacity, E2 induced an increase in the osteogenic and chondrogenic abilities of both pBMSCs, but adipogenic ability may increased only in NF-pBMSCs. These results demonstrate that E2 could affect both genders of newborn donor-derived MSCs, but the regulatory role of E2 varies depending on gender-dependent characteristics even though the original newborn donors had not been affected by functional steroid hormones.

The purpose of this study is to confirm whether spontaneous adipocyte generation during chondrogenic induction culture affects the chondrogenic differentiation of porcine skin-derived stem cells (pSSCs). For this purpose, chondrogenic differentiation characteristics and specific marker gene expression were analyzed using cell lines showing different characteristics of spontaneous adipocyte formation. Of the four different lines of pSSCs, the pSSCs-IV line showed higher Oil red O (ORO) and glycosaminoglycan (GAG) extraction levels. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed that the levels of adipogenic markers peroxisome proliferator-activated receptor gamma 2 (PPARγ2) and adipocyte Protein 2 (aP2) mRNAs were significantly higher in pSSCs-IV than those of the other pSSC lines (P<0.05). Among three chondrogenic markers, collagen type II (Col II) and sex determining region Y-box (Sox9) mRNAs were strongly expressed in pSSCs-IV (P<0.05), but not in aggrecan (Agg), which was significantly higher in pSSCs-II (P<0.05). These results demonstrate that the spontaneous adipocyte generation during chondrogenic differentiation has a positive effect on the chondrogenesis of pSSCs. More research is needed on the correlation between adipocyte generation and cartilage formation.

Metformin (1,1-dimethylbiguanide hydrochloride), derived from French lilac (Galega officinalis), is a first-line anti-diabetic drug prescribed for patients with type 2 diabetes. However, the role of metformin in odontoblastic cell differentiation is still unclear. This study therefore undertook to examine the effect of metformin on regulating odontoblast differentiation in MDPC-23 mouse odontoblastic cells derived from mouse dental papilla cells. As compared to controls, metformin significantly accelerated the mineralization, significantly increased and accelerated the expressions of ALP and Col I mRNAs, and significantly increased the accelerated expressions of DSPP and DMP-1 mRNAs, during differentiation of MDPC-23 cells. There was no alteration in cell proliferation of MDPC-23 cells, on exposure to metformin. These results suggest that the effect of metformin on MDPC-23 mouse odontoblastic cells derived from mouse dental papilla cells, facilitates the odontoblast differentiation and mineralization, without altering the cell proliferation.

Mesenchymal stem cells (MSCs) have been considered an alternative source of neuronal lineage cells, which are difficult to isolate from brain and expand in vitro. Previous studies have reported that MSCs expressing Nestin (Nestin+ MSCs), a neuronal stem/progenitor cell marker, exhibit increased transcriptional levels of neural development-related genes, indicating that Nestin+ MSCs may exert potential with neurogenic differentiation. Accordingly, we investigated the effects of the presence of Nestin+ MSCs in bone-marrow-derived primary cells (BMPCs) on enhanced neurogenic differentiation of BMPCs by identifying the presence of Nestin+ MSCs in uncultured and cultured BMPCs. The percentage of Nestin+ MSCs in BMPCs was measured per passage by double staining with Nestin and CD90, an MSC marker. The efficiency of neurogenic differentiation was compared among passages, revealing the highest and lowest yields of Nestin+ MSCs. The presence of Nestin+ MSCs was identified in BMPCs before in vitro culture, and the highest and lowest percentages of Nestin+ MSCs in BMPCs was observed at the third (P3) and fifth passages (P5). Moreover, significantly the higher efficiency of differentiation into neurons, oligodendrocyte precursor cells and astrocytes was detected in BMPCs at P3, compared with P5. In conclusion, these results demonstrate that neurogenic differentiation can be enhanced by increasing the proportion of Nestin+ MSCs in cultured BMPCs.

To gain insights into the role of purinergic receptors in human dental pulp cells (hDPCs) differentiation, we characterized the expression and functional activity of P2Y1 receptors and investigated the effects of ADP on the proliferation and differentiation of this pulp stem-like cell population. Our data showed that ADP did not induce cell proliferation to expose the various ADP concentrations for 72 hours, but the proliferative capacity of hDPCs was inhibited at higher ATP concentrations (100 μM). Using RT-PCR analysis, we found that ADP induced several P2Y receptors including P2Y1 as well as odontoblastic differentiation genes, dentin matrix protein 1 (DMP1) and dentin sialophosphoprotein (DSPP) in a dose-dependent manner. The effects of ADP on the expression of DMP-1 and DSPP mRNA were prevented by the P2Y1 antagonist MRS2179. The extracellular matrix calcium deposits were clearly observed in ADP-treated hDPCs by alizarin red S staining. Quantitative measurement of mineralization induced by ADP was significantly inhibited in MRS2179-treated hDPCs. These results may provide new insights into the molecular regulation of the differentiation of hDPCs.

The mesenchymal stem cells (MSC) has been investigated as a source of stem cell therapy to replace and treat damaged cells. Human endometrial epithelial and stromal cells was isolated from hysterectomy tissue and the direct evidence of stem/progenitor cells in the human endometrium was identified. Endometrium derived stem cells (EnMSCs) are known to have a high proliferative ability, genetic stability, lack of tumorigenicity and low immnunogenicity during long-term cultivation. Here, we aimed to identify MSC in canine endometrium and characterize its potential to differentiate into decidua cells. EnMSCs were isolated from thrown-away spayed uterus of adult canine depending on their estrus cycle, and identified by flow cytometry, immunocytochemistry and flow cytometry with MSC specific markers. We then characterized the ability of EnMSCs by the doubling-time analysis, colony-forming units and MSC differentiation assays. Isolated EnMSCs expressed stem cell specific genes (Sox2, Oct4, Nanog, MCAM, Endoglin, Susd2 and IGTB) and MSC surface markers (CD90, CD44 and CD117). EnMSCs are also differentiated into adipogenic, osteogenic and chondrogenic cells morphologically under modified conditions with the expression of lineage specific genetic markers. EnMSCs showed higher proliferation ability than canine amniotic fluid derived MSCs which were used as a positive control. EnMSCs were cultured at low density (10, 20, cells/cm2) and initiated to form small colonies of loosely-arranged cells and gradually formed large colonies of densely-packed cells which underwent self-renewal with high proliferative potential which is similar to the clonogenicity feature of human endometrium-derived stem cells. EnMSCs were then induced to differentiate into decidua cells with 0.5 mM dbcAMP. After 14 days, EnMSCs changed their morphology into the elongated and rounded shape. The induced decidual cells expressed PRL and IGFBP1 which are typically expressed in decidua cells. In conclusion, we successfully isolated and characterized MSC in the canine endometrium which differentiated into decidua cells. These results showed that endometrium may be a promising source of stem cells, and furthermore raise the possibility of canine EnMSCs as a novel hypothetical decidualisation model of infertility associated with decidualisation insufficiency and implantation failure.

Little is known to date about neural development of pig and directed differentiation of porcine pluripotent stem cells (PSCs) to neuronal cells remains elusive. To determine whether soluble factors from glioblastoma multiforme (GBM) promoted the neural differentiation from porcine induced PSCs (iPSCs), cells were treated cultured media of GBM cells. First of all, we isolated and established primary GBM cell line (WHO grade IV). The cellular morphology of GBM cancer cell line are dendritic-like with positive expression in NESTIN, SOX2, VIMENTIN and GFAP using immunofluorescence analysis. G-banded karyotype from primary GBM cell line revealed severe numerical chromosomal aberrations. GBM-cultured medium (CM) treated iPSC-NPCs survive well in vitro when supplemented with a combination of growth factors, including EGF and bFGF. The GBM-CM treated differentiated cells showed an increased mRNA expression level of astrocyte marker, GFAP and the dopaminergic neuron marker, tyrosine hydroxylase (TH). However, there was no significant difference in mRNA expression level of oligodendrocyte marker, MBP. The protocol developed in the present study for large animal models might provide an exciting tool to bridge the present gaps in neuroscience studies between rodents and humans.