• IMMUNE NETWORK
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• v.2 no.3
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• pp.166-174
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• 2002

Background: Human umbilical cord bloods, which could be taken during the delivery are utilized as a source of hematopoietic stem cells. Also in cord blood, there are several kinds of stem cells such as endothelial and mesenchymal stem cells. Methods: We isolated the mesenchymal stem cells from human umbilical cord bloods and confirmed the differentiation of these cells into osteoblast progenitor cells. The mesenchymal stem cells derived from umbilical cord blood have the ability to differentiate into specific tissue cells, which is one of characteristics of stem cells. These cells were originated from the multipolar shaped cells out of adherent cells of the umbilical cord blood mononuclear cell culture. Results: The mesenchymal stem cells expressed cell surface antigen CD13, CD90, CD102, CD105, ${\alpha}$-smooth muscle actin and cytoplasmic antigen vimentine. Having cultrued these cells in bone formation media, we observed the formation of extracellular matrix and the expression of alkaline phosphatase and of mRNA of cbfa-1, ostoecalcin and type I collagen. Conclusion: From these results we concluded that the cells isolated from the umbilical cord blood were mesenchymal stem cells, which we could differentiate into osteoblast when cultured in bone formation media. In short, it is suggested that these cells could be used as a new source of stem cells, which has the probability to alternate the embryonic stem cells.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.1
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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.

• Journal of Life Science
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• v.21 no.8
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• pp.1199-1203
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• 2011

The present study evaluated the beneficial effects of polycalcium (a mixture of Polycan and calcium lactate-gluconate 1:9 [g/g]) on osteoporosis using in vitro assays. Cell proliferation and alkaline phosphatase activities of osteoblasts (human primary osteoblasts) and osteoclast differentiation of RAW264.7 cells (murine osteoclast progenitor cells) treated with different concentrations of polycalcium for various periods were assessed. Osteoblast proliferation was stimulated and prevented RANKL-induced osteoclast differentiation of RAW264.7 cells. These results support the development of ideal anti-osteoporotic agents, such as polycalcium, that exhibit properties that accelerate bone formation and inhibit bone resorption.

• Development and Reproduction
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• v.14 no.4
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• pp.233-241
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• 2010

Human adipose stem cells are an abundant, readily available population of multipotent progenitor cells that reside in adipose tissue and these cells have characteristics very similar to bone marrow mesenchymal stromal cells (BMMSCs). However, liposuction procedure, donor age, body mass index, and harvesting sites might generate differences in the initial cell population and the preparations are a heterogeneous mixture of precursors with different subsets. Therefore, in this study, we investigated the characteristics of human thigh adipose stem cells and the differentiation potential into mesodermal and endodermal lineage. Thigh adipose stem cells maintained fibroblast-like morphology similar to BM-MSCs and they underwent average 56.5 doublings and produced $5{\times}10^{22}$ cells. These cells expressed SCF, Oct4, nanog, vimentin, CK18, FGF5, NCAM, Pax6, BMP4, HNF4a, nestin, GATA4, HLA-ABC, and HLA-DR genes at p3 and they also expressed Oct4, Thy-1, FSP, vWF, vimentin, desmin, CK18, CD54, CD4, CD106, CD31, a-SMA, HLA-ABC proteins. Moreover, they could differentiate into mesodermal lineage cells such as adipocyte, osteoblast and chondrocyte. In addition, they also differentiated into insulin secreting cells in our culture condition. In conclusion, human thigh adipose stem cells retain proliferative potential and expression patterns similar to BM-MSCs and they also differentiate into various cell types. Thus, human thigh adipose stem cells might be useful alternative cell source for clinical application.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.207-218
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• 2001

The purpose of this study was to investigate the direct inhibitory effect of calcium hydroxide materials on differentiation and activation of osteoclast. we used the osteoclast progenitor cells isolated from bone marrow cell of chick embryo tibia and four experimental materials [$Ca(OH)_2$ powder, Metapaste$^{(R)}$, Vitapex$^{(R)}$, Pulpdent$^{(R)}$] diluted at 0.1, 0.01, $0.05{\mu}g/ml$. There were measured both the number of differentiated osteoclast and the area of resorption lacunae. Also, we conducted MTT assay on U2OS osteoblast to examine of cytotoxic effect and obtained following result. 1. Considering the result of the inhibitory effects upon osteoclast differentiation, There were shown a significant difference increased in the following order: Metapaste$^{(R)}$, $Ca(OH)_2$ powder, Vitapex$^{(R)}$. But no significant difference was found in pulpdent group that the number of differentiated osteoclast was increased at all concentrations(p<0.05). 2. Among the three experimental groups, that is, $Ca(OH)_2$ powder, Metapaste$^{(R)}$, Vitapex$^{(R)}$ at $0.1{\mu}g/ml$ dilution that were statistically significant in reduction of the number of differentiated osteoclast. Vitapex group showed significant cytotoxic effect compared to control and another two groups exhibited no significant difference. Also, 0.2% DMSO group was shown statistically siginificant cytotoxicity (p<0.05). 3. Examining pattern and measured area of resorption lacunae in the control and the three experimental groups ,that is, $Ca(OH)_2$ powder, Metapaste$^{(R)}$, Vitapex$^{(R)}$ at $0.1{\mu}g/ml$ dilution, except $Ca(OH)_2$ powder group, statistically significant differences were found between experimental groups and control group. Also, DMSO group showed statistically significant decrease (p<0.05). From these results, we think that calcium hydroxide is responsible for suppression of hard tissue resorption by a direct inhibition of dfferentiation and activation of osteoclast.