• IMMUNE NETWORK
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• 제2권3호
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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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권4호
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• pp.205-212
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• 2009

Purpose : The purpose of this study was to examine the expression of various angiogenic factors during osteoblastic differentiation of periostealderived cells and the effects of osteogenic inductive medium of periosteal-derived cells on the proliferation of endothelial progenitor cells. Materials and methods : Periosteal-derived cells were obtained from mandibular periosteums and introduced into the cell culture. After passage 3, the cells were divided into two groups and cultured for 21 days. In one group, the cells were cultured in the DMEM supplemented with osteogenic inductive agent, including 50g/ml L-ascorbic acid 2-phosphate, 10 nM dexamethasone and 10 mM -glycerophosphate. In the other group, they were cultured in DMEM supplemented without osteogenic inductive agent. VEGF isoforms, VEGFR-1, VEGFR-2, and neuropilin-1 mRNA expression was observed. Human umbilical cord blood-derived endothelial progenitor cell proliferation was also observed. Results : The expression of VEGF isoforms was higher in osteogenic inductive medium than in non-osteogenic inductive medium. The expression of VEGFR-2 was also higher in osteogenic inductive medium than in non-osteogenic inductive medium. However, the expression of VEGFR-1 and neuropilin-1 was similar in both osteogenic inductive medium and non-osteogenic inductive medium. In addition, conditioned medium from differentiated periosteal-derived cells stimulated human umbilical cord blood-derived endothelial progenitor cell numbers compared to conditioned medium from non-differentiated periosteal-derived cells. Conclusion : These results suggest that in vitro osteoblastic differentiation of periosteal-derived cells has angiogenic capacity to support endothelial progenitor cell numbers.

• International Journal of Oral Biology
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• 제36권3호
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• pp.117-122
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• 2011

Endothelial cells are a vital constituent of most mammalian organs and are required to maintain the integrity of these tissues. These cells also play a major role in angiogenesis, inflammatory reactions, and in the regulation of thrombosis. Angiogenesis facilitates pulp formation and produces the vessels which are essential for the maintenance of tooth homeostasis. These vessels can also be used in bone and tissue regeneration, and in surgical procedures to place implants or to remove cancerous tissue. Furthermore, endothelial cell regeneration is the most critical component of the tooth generation process. The aim of the present study was to stimulate endothelial regeneration at a site of acute cyclophosphamide (CP)-induced endothelial injury by treatment with human umbilical cord-derived endothelial/mesenchymal stem cells (hEPCs). We randomly assigned 16 to 20-week-old female NOD/SCID mice into three separate groups, a hEPC ($1{\times}10^5$ cells) transplanted, 300mg/kg CP treated and saline (control) group. The mice were sacrificed on days 5 and 10 and blood was collected via the abdominal aorta for analysis. The alanine transaminase (ALT), aspartate aminotransferase (AST), serum alkaline phosphatase (s-ALP), and albumin (ALB) levels were then evaluated. Tissue sections from the livers and kidneys were stained with hematoxylin and eosin (HE) for microscopic analysis and were subjected to immunohistochemistry to evaluate any changes in the endothelial layer. CP treatment caused a weight reduction after one day. The kidney/body weight ratio increased in the hEPC treated animals compared with the CP only group at 10 days. Moreover, hEPC treatment resulted in reduced s-ALP, AST, ALT levels compared with the CP only group at 10 days. The CP only animals further showed endothelial injuries at five days which were recovered by hEPC treatment at 10 days. The number of CD31-positive cells was increased by hEPC treatment at both 5 and 10 days. In conclusion, the CP-induced disruption of endothelial cells is recovered by hEPC treatment, indicating that hEPC transplantation has potential benefits in the treatment of endothelial damage.