• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.31 no.3
• /
• pp.239-247
• /
• 2005

This study demonstrated that xenogenic human marrow mesenchymal stem cells (hMSCs) could elicit the regeneration of the sensory nerve after axotomy in the adult rats infraorbital nerves without immunosuppression. For this, we evaluated the behavioral testing for functional recovery of the nerve and histological findings at weeks 3 and 5 compared to controls. Xenogenic hMSCs did not evoke any significant inflammatory or immunologic reaction after systemic and local administrations. HMSCs-treated rats exhibited significant improvement on sensory recovery tested with von Frey monofilaments. At 5 postoperative weeks, in the hMSCs treated nerve, expression of myelin basic protein (MBP), neurofilament (NF) at the site of axotomy was higher than control. And mRNA expression of neurotropin receptor Trk precursor (TrkPre), nerve growth factor receptor (NGFR) and neuropeptide (NPY) in trigeminal ganglion were also higher. The number of myelinated nerve at distal stump and cells in trigeminal ganglion were higher in hMSC treated rats. So it was supposed that transplanted MSCs contributed to reducing post-traumatic degeneration and production of neurotrophic factors. Immunofluorescence labeling showed small portion of hMSCs (<10%) expressed a phenotypic marker of Schwann cell (S-100). Xenogenic or allogenic mesenchymal stem cells might have immune privileged characteristics and useful tool for cell based nerve repair.

• Molecules and Cells
• /
• v.43 no.10
• /
• pp.848-855
• /
• 2020

Cells assemble stress granules (SGs) to protect their RNAs from exposure to harmful chemical reactions induced by environmental stress. These SGs release RNAs, which resume translation once the stress is relieved. During stem cell differentiation, gene expression is altered to allow cells to adopt various functional and morphological features necessary to differentiate. This process induces stress within a cell, and cells that cannot overcome this stress die. Here, we investigated the role of SGs in the progression of stem cell differentiation. SGs aggregated during the neuronal differentiation of human bone marrow-mesenchymal stem cells, and not in cell lines that could not undergo differentiation. SGs were observed between one and three hours post-induction; RNA translation was restrained at the same time. Immediately after disassembly of SGs, the expression of the neuronal marker neurofilament-M (NF-M) gradually increased. Assembled SGs that persisted in cells were exposed to salubrinal, which inhibited the dephosphorylation of eukaryotic translation initiation factor 2 subunit 1 (eIF2α), and in eIF2α/S51D mutant cells. When eIF2α/S51A mutant cells differentiated, SGs were not assembled. In all experiments, the disruption of SGs was accompanied by delayed NF-M expression and the number of neuronally differentiated cells was decreased. Decreased differentiation was accompanied by decreased cell viability, indicating the necessity of SGs for preventing cell death during neuronal differentiation. Collectively, these results demonstrate the essential role of SGs during the neuronal differentiation of stem cells.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.34 no.4
• /
• pp.419-427
• /
• 2008

The present study aimed to investigate the osteogenic potentials of differentiated osteoblast-like cells (DOCs) induced from bone marrow-derived mesenchymal stem cells (MSCs) on ${\beta}-tricalcium$ phosphate (${\beta}-TCP$) with recombinant human bone morphogenetic protein (rhBMP-2) in vitro. Osteoblast differentiation was induced in confluent cultures by adding 100 nM dexamethasone, 10 mM ${\beta}$-glycerophosphate, 50 mM L-ascorbic acid. The Alizarin red S staining and reverse transcriptase-polymerase chain reaction (RT-PCR) were perfomed to examine the mRNA expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN), receptor activator for nuclear factor ${\kappa}B$ ligand (RANKL), runt-related transcription factor 2 (RUNX2), collagen-Ⅰ (COL-Ⅰ). There were no significant differences in the osteogenic potentials of DOCs induced from MSCs on ${\beta}-TCP(+/-)$. According to the incubation period, there were significant increasing of Alizadin red S staining in the induction 3 weeks. The mRNA expression of ALP, RUNX2, and RANKL were higher in DOCs/${\beta}-TCP(-)$ than DOCs/${\beta}-TCP(+)$. According to rhBMP-2 concentrations, the mRNA expression of BSP was significantly increased in DOCs/${\beta}-TCP(+)$ compared to that of DOCs/${\beta}-TCP(-)$ on rhBMP 10 ng/ml. Our study presented the ${\beta}-TCP$ will have the possibility that calcium phosphate directly affect the osteoblastic differentiation of the bone marrowderived MSCs.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.7 no.3
• /
• pp.178-184
• /
• 2002

High-throughput screening has become a popular method used to identify new “leads”for potentially therapeutic compounds. Further screening of these lead compounds is typically done with secondary assays which may utilize living, functioning cells as screening tools. A problem (or benefit) with these cell-based assays is that living cells are very sensitive to their environment. We have been interested in the process of stem cell migration and how it relates to the cellular therapy of bone marrow transplantation. In this study we describe a secondary, cell-based assay for screening the effects of various in-vitro conditions on Immature Hematopoietic Cell (IHC) migration. Our results have revealed many subtle factors, such as the cell's adhesive characteristics, or the effect of a culture's growth phase, that need to be accounted for in a screening protocol. Finally, we show that exponentially glowing KG1a cells (a human IHC cell line) were 10 times more motile than those in the lag or stationary phases. These data strongly suggest that KG1a cells secrete a chemokinetic factor during the exponential growth phase of a culture.

• Reproductive and Developmental Biology
• /
• v.34 no.1
• /
• pp.1-6
• /
• 2010

Mesenchymal stem cells (MSCs) have the multipotent capacity and this potential can be applied for obtaining valuable cell types which can use for cell therapy on various regenerative diseases. However, insufficient availability of cellular source is the major problem in cell therapy field using adult stem cell sources. Recently, human embryonic stem cells (hESCs) have been highlighted to overcome a limitation of adult cellular sources because they retain unlimited proliferation capacity and pluripotency. To use of hESCs in cell therapy, above all, animal pathogen free culture system and purification of a specific target cell population to avoid teratoma formation are required. In this study, we describe the differentiation of a mesenchymal stem cell-like cells population from feeder-free cultured hESCs(hESC-MSCs) using direct induction system. hESC-MSCs revealed characteristics similar to MSCs derived from bone marrow, and undifferentiated cell markers were extremely low in hESC-MSCs in RT-PCR, immunostaining and FACS analyses. Thus, this study proffer a basis of effective generation of specialized human mesenchymal stem cell types which can use for further clinical applications, from xenofree cultured hESCs using direct induction system.

• Proceedings of the Korean Society of Developmental Biology Conference
• /
• 2003.10a
• /
• pp.78-78
• /
• 2003

Adult stem cells can make identical copies of themselves for long periods of time. They also give rise to many differentiated mature cell types that have characteristic morphology and specialized function. Human adult stem cells are the attractive raw materials for the cell/tissue therapy, however, it is not easy to get from the adult tissues. In the present study, we tried to isolate a cell population derived from human umbilical cord vein which has been discarded after birth. The cells were isolated after treatment of the umbilical vein with collagenase or trypsin. After 3 days of culture, two kinds of cell populations were found consisting of adherent cells with endothelial cell-like and fibroblast-like morphology, respectively. When these cells were subcultured 12 times over a period of 3 months, almost cells appeared uniformly to exhibit fibroblastoid morphology which was different from that of mesenchymal stem cells obtained from human bone marrow The results of RT-PCR analyses showed distinct expression of BMP-4, oct-4, and SCF genes but not of GATA, PAX-6 and Brachyury genes. On immunohistochemical staining, the cells were negative for the von Willebrand factor(vWF), alpha-smooth muscle actin and placental alkaline phosphatase. From these observations, it is suggested that stem-like cells might be present in human umbilical cord vein.

• Journal of Periodontal and Implant Science
• /
• v.51 no.5
• /
• pp.329-341
• /
• 2021

Purpose: Periodontal treatment aims at complete regeneration of the periodontium, and developing strategies for periodontal regeneration requires a deep understanding of the tissues composing the periodontium. In the present study, the stemness characteristics and gene expression profiles of cementum-derived cells (CDCs) were investigated and compared with previously established human stem cells. Candidate marker proteins for CDCs were also explored. Methods: Periodontal ligament stem cells (PDLSCs), pulp stem cells (PULPSCs), and CDCs were isolated and cultured from extracted human mandibular third molars. Human bone marrow stem cells (BMSCs) were used as a positive control. To identify the stemness of CDCs, cell differentiation (osteogenic, adipogenic, and chondrogenic) and surface antigens were evaluated through flow cytometry. The expression of cementum protein 1 (CEMP1) and cementum attachment protein (CAP) was investigated to explore marker proteins for CDCs through reverse-transcription polymerase chain reaction. To compare the gene expression profiles of the 4 cell types, mRNA and miRNA microarray analysis of 10 samples of BMSCs (n=1), PDLSCs (n=3), PULPSCs (n=3), and CDCs (n=3) were performed. Results: The expression of mesenchymal stem cell markers with a concomitant absence of hematopoietic markers was observed in PDLSCs, PULPSCs, CDCs and BMSCs. All 4 cell populations also showed differentiation into osteogenic, adipogenic, and chondrogenic lineages. CEMP1 was strongly expressed in CDCs, while it was weakly detected in the other 3 cell populations. Meanwhile, CAP was not found in any of the 4 cell populations. The mRNA and miRNA microarray analysis showed that 14 mRNA genes and 4 miRNA genes were differentially expressed in CDCs vs. PDLSCs and PULPSCs. Conclusions: Within the limitations of the study, CDCs seem to have stemness and preferentially express CEMP1. Moreover, there were several up- or down-regulated genes in CDCs vs. PDLSCs, PULPSCs, and BMSCs and these genes could be candidate marker proteins of CDCs.

• BMB Reports
• /
• v.56 no.9
• /
• pp.482-487
• /
• 2023

Hematopoiesis is regulated by crosstalk between long-term repopulating hematopoietic stem cells (LT-HSCs) and supporting niche cells in the bone marrow (BM). Here, we describe the role of KAI1, which is mainly expressed on LT-HSCs and rarely on other hematopoietic stem-progenitor cells (HSPCs), in niche-mediated LT-HSC maintenance. KAI1 activates TGF-β1/Smad3 signal in LT-HSCs, leading to the induction of CDK inhibitors and inhibition of the cell cycle. The KAI1-binding partner DARC is expressed on macrophages and stabilizes KAI1 on LT-HSCs, promoting their quiescence. Conversely, when DARC+ BM macrophages were absent, the level of surface KAI1 on LT-HSCs decreases, leading to cell-cycle entry, proliferation, and differentiation. Thus, KAI1 acts as a functional surface marker of LT-HSCs that regulates dormancy through interaction with DARC-expressing macrophages in the BM stem cell niche. Recently, we showed very special and rare macrophages expressing α-SMA+ COX2+ & DARC+ induce not only dormancy of LT-HSC through interaction of KAI1-DARC but also protect HSCs by down-regulating ROS through COX2 signaling. In the near future, the strategy to combine KAI1-positive LT-HSCs and α-SMA/Cox2/DARC triple-positive macrophages will improve the efficacy of stem cell transplantation after the ablative chemo-therapy for hematological disorders including leukemia.

• Biomedical Science Letters
• /
• v.22 no.1
• /
• pp.1-8
• /
• 2016

Several studies have investigated the various effects of dexamethasone (Dex) on the proliferation and differentiation of mesenchymal stem cells (MSCs). Previously, we reported that co-treatment with L-ascorbic acid 2-phosphate and fibroblast growth factor (FGF)-2 maintained differentiation potential in MSCs through expression of hepatocyte growth factor (HGF). In this study, we investigated the effects of co-treatment with FGF-2 and Dex on the proliferation and differentiation potential of MSCs during a 2-month culture period. Co-treatment with FGF-2 and Dex increased approximately a 4.7-fold higher accumulation rate of MSC numbers than that by FGF-2 single treatment during a 2-month culture period. Interestingly, co-treatment with FGF-2 and Dex increased expression of HGF and maintained adipogenic differentiation potential during this culture period. These results suggest that co-treatment with FGF-2 and Dex preserves the proliferation and differentiation potential during long-term culture.

• Asian Oncology Nursing
• /
• v.12 no.2
• /
• pp.132-138
• /
• 2012

Purpose: The purpose of this study was to identify the performance status and quality of life (QOL) of patients after hematopoietic stem cell transplantation (HSCT) according to period of survival. Methods: Participants consists of 83 HSCT patients who were being treated regularly at out-patient clinic in two general hospitals in D city. Data were collected using questionnaires that were modified by Functional Assessment of Cancer Therapy-Bone Marrow Transplabtation (FACT-BMT) scale and Eastern Cooperative Oncology Group (ECOG). Results: The unrelated HSCT group's survival period was significantly worse than related HSCT group and autologous HSCT group. Performance status of the group with more than 3 years survival was significantly higher than that of the group with less than a year survival. The mean score of total QOL of HSCT patients was 2.69 out of 4. Total QOL was not significantly different among period of survival less than 1 year, 1-3 years, and more than 3 years. But BMT QOL was shown that the group with more than 3 years survival was higher than the groups with less than a year survival. Conclusion: Performance status and BMT QOL of the group with less than 1 year survival was significantly lowered than the groups with more than 3 years survival.