• The Korean Journal of Physiology and Pharmacology
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• v.24 no.6
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• pp.463-472
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• 2020

Direct reprogramming, also known as a trans-differentiation, is a technique to allow mature cells to be converted into other types of cells without inducing a pluripotent stage. It has been suggested as a major strategy to acquire the desired type of cells in cell-based therapies to repair damaged tissues. Studies related to switching the fate of cells through epigenetic modification have been progressing and they can bypass safety issues raised by the virus-based transfection methods. In this study, a protocol was established to directly convert fully differentiated fibroblasts into diverse mesenchymal-lineage cells, such as osteoblasts, adipocytes, chondrocytes, and ectodermal cells, including neurons, by means of DNA demethylation, immediately followed by culturing in various differentiating media. First, 24 h exposure of 5-azacytidine (5-aza-CN), a well-characterized DNA methyl transferase inhibitor, to NIH-3T3 murine fibroblast cells induced the expression of stem-cell markers, that is, increasing cell plasticity. Next, 5-aza-CN treated fibroblasts were cultured in osteogenic, adipogenic, chondrogenic, and neurogenic media with or without bone morphogenetic protein 2 for a designated period. Differentiation of each desired type of cell was verified by quantitative reverse transcriptase-polymerase chain reaction/western blot assays for appropriate marker expression and by various staining methods, such as alkaline phosphatase/alizarin red S/oil red O/alcian blue. These proposed procedures allowed easier acquisition of the desired cells without any transgenic modification, using direct reprogramming technology, and thus may help make it more available in the clinical fields of regenerative medicine.

• Development and Reproduction
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• v.12 no.1
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• pp.31-39
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• 2008

Neural tissue has limited intrinsic capacity of repair after injury, and the identification of alternate sources of neural stem cells has broad clinical potential. We isolated mesechymal-like stem cells from human adipose tissues (AT-MSCs), and studied on transdifferentiation-promoting conditions in neural cells. Dopaminergic and cholinergic neuron induction of AT-MSCs was also studied. Neural differentiation was induced by adding bFGF, EGF, dimethyl sulphoxide (DMSO) and butylated hydroxyanisole(BHA) in N2 Medium and N2 supplement. The immunoreactive cells for $\beta$-tubulin III, a neuron-specific marker, GFAP, an astrocyte marker, or Gal-C, an oligodendrocyte marker, were found. AT-MSCs treated with bFGF, SHH and FGF8 were differentiatied into dopaminergic neurons that were immunopositive for TH antibody. Differentiation of MSCs to cholinergic neurons was induced by combined treatment with basic fibroblast growth factor (bFGF), retinoic acid (RA) and sonic hedgehog (Shh). AT-MSCs treated with DMSO and BHA rapidly assumed the morphology of multipolar neurons. Both immunocytochemistry and RT-PCR analysis indicated that the expression of a number of neural markers including neuro D1, $\beta$-tubulin III, GFAP and nestinwas markedly elevated during this acute differentiation. While the stem cell markers such as SCF, C-kit, and Stat-3 were not expressed after preinduction medium culture, we confirmed the differentiation of dopaminergic and cholinergic neurons by TH/$\beta$-tubulin III or ChAT/ $\beta$-tubulin III positive cells. Conclusively, AT-MSCs can be differentiated into dopaminergic and cholinergic neuronsand these findings suggest that AT-MSCs are alternative cell source of treatment for neurodegenerative diseases.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.831-835
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• 2014

Background: Predictor factors determining complete response to treatment are still not clearly defined. We aimed to evaluate clinicopathological features, risk factors, treatment responses, and survival analysis of patient with advanced nonseminomatous GCTs (NSGCTs). Materials and Methods: Between November 1999 and September 2011, 140 patients with stage II and III NSGCTs were referred to our institutions and 125 patients with complete clinical data were included in this retrospective study. Four cycles of BEP regimen were applied as a first-line treatment. Salvage chemotherapy and/or high-dose chemotherapy (HDCT) with autologous stem cell transplantation were given in patients who progressed after BEP chemotherapy. Post-chemotherapy surgery was performed in selected patients with incomplete radiographic response and normal tumor markers. Results: The median age was 28 years. For the good, intermediate and poor risk groups, compete response rates (CRR) were, 84.6%, 67.9% and 59.4%, respectively. Extragonadal tumors, stage 3 disease, intermediate and poor risk factors, rete testis invasion were associated with worse outcomes. There were 32 patients (25.6%) with non-CR who were treated with salvage treatment. Thirty-one patients died from GCTs and 94% of them had stage III disease. Conclusions: Even though response rates are high, some patients with GCTs still need salvage treatment and cure cannot be achieved. Non-complete response to platinium-based first-line treatment is a negative prognostic factor. Our study confirmed the need for a prognostic and predictive model and more effective salvage approaches.

• Journal of Ginseng Research
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• v.36 no.1
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• pp.86-92
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• 2012

The glioblastoma multiforme (GBM) is the most common malignant brain tumor in adults. Despite combination treatments of radiation and chemotherapy, the survival periods are very short. Therefore, this study was conducted to assess the potential of ginsenoside $F_2$ (F2) to treat GBM. In in vitro experiments with glioblastoma cells U373MG, F2 showed the cytotoxic effect with $IC_{50}$ of 50 ${\mu}g/mL$ through apoptosis, confirmed by DNA condensation and fragmentation. The cell population of cell cycle sub-G1 as indicative of apoptosis was also increased. In xenograft model in SD rats, F2 at dosage of 35 mg/kg weight was intravenously injected every two days. This reduced the tumor growth in magnetic resonance imaging images. The immunohistochemistry revealed that the anticancer activity might be mediated through inhibition of proliferation judged by Ki67 and apoptosis induced by activation of caspase-3 and -8. And the lowered expression of CD31 showed the reduction in blood vessel densities. The expression of matrix metalloproteinase-9 for invasion of cancer was also inhibited. The cell populations with cancer stem cell markers of CD133 and nestin were reduced. The results of this study suggested that F2 could be a new potential chemotherapeutic drug for GBM treatment by inhibiting the growth and invasion of cancer.

• Development and Reproduction
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• v.11 no.3
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• pp.235-243
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• 2007

Human umbilical cord blood(HUCB) contains a rich source of hematopoietic stem cells, mesenchymal stem cells and endothelial cell precursors. Mesenchymal stem cells(MSCs) in HUCB are multipotent stem cells, differ from hematopoietic stem cells and can be differentiated into neural cells. We studied on transdifferentiation-promoting conditions in neural cells and cholinergic neuron induction of HUCB-derived MSCs. Neural differentiation was induced by addingdimethyl sulphoxide(DMSO) and butylated hydroxyanisole(BHA) in Dulbeco's Modified Essential Medium(DMEM) and fetal bovine serum(FBS). Differentiation of MSCs to cholinergic neurons was induced by combined treatment with basic fibroblast growth factor(bFGF), retinoic acid(RA) and sonic hedgehog(Shh). MSCs treated with DMSO and BHA rapidly assumed the morphology of multipolar neurons. Both immunocytochemistry and RT-PCR analysis indicated that the expression of a number of neural markers including $\beta$-tubulin III, GFAP and MBP, was markedly elevated during this acute differentiation. The differentiation rate was about $32.3{\pm}2.9%$ for $\beta$-tubulin III-positive cells, $11.0{\pm}0.9%$ for GFAP, and $9.4{\pm}1.0%$ for Gal-C. HUCB-MSCs treated combinatorially with bFGF, RA and Shh were differentiated into cholinergic neurons. After cholinergic neuronal differentiation, the $\beta$-tubulin III-positive cell population of total cells was $31.3{\pm}3.2%$ and of differentiated neuronal population, $70.0{\pm}7.8%$ was ChAT-positive showing 3 folds higher in cholinergic population than neural induction. Conclusively, HUCB-derived MSCs can be differentiated into neural and cholinergic neurons and these findings suggest that HUCB are alternative cell source of treatment for neurodegenerative diseases such as Alzheimer's disease.

• Molecules and Cells
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• v.38 no.3
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• pp.221-228
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• 2015

Because Schwann cells perform the triple tasks of myelination, axon guidance and neurotrophin synthesis, they are candidates for cell transplantation that might cure some types of nervous-system degenerative diseases or injuries. However, Schwann cells are difficult to obtain. As another option, ectomesenchymal stem cells (EMSCs) can be easily harvested from the nasal respiratory mucosa. Whether fibrin, an important transplantation vehicle, can improve the differentiation of EMSCs into Schwann-like cells (SLCs) deserves further research. EMSCs were isolated from rat nasal respiratory mucosa and were purified using anti-CD133 magnetic cell sorting. The purified cells strongly expressed HNK-1, nestin, $p75^{NTR}$, S-100, and vimentin. Using nuclear staining, the MTT assay and Western blotting analysis of the expression of cell-cycle markers, the proliferation rate of EMSCs on a fibrin matrix was found to be significantly higher than that of cells grown on a plastic surface but insignificantly lower than that of cells grown on fibronectin. Additionally, the EMSCs grown on the fibrin matrix expressed myelination-related molecules, including myelin basic protein (MBP), 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) and galactocerebrosides (GalCer), more strongly than did those grown on fibronectin or a plastic surface. Furthermore, the EMSCs grown on the fibrin matrix synthesized more neurotrophins compared with those grown on fibronectin or a plastic surface. The expression level of integrin in EMSCs grown on fibrin was similar to that of cells grown on fibronectin but was higher than that of cells grown on a plastic surface. These results demonstrated that fibrin not only promoted EMSC proliferation but also the differentiation of EMSCs into the SLCs. Our findings suggested that fibrin has great promise as a cell transplantation vehicle for the treatment of some types of nervous system diseases or injuries.

• Journal of Veterinary Clinics
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• v.28 no.4
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• pp.399-402
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• 2011

In recent years, the mesenchymal stem cells (MSC) derived from various tissues have been widely tested for developing cell therapies, tissue repair and transplantation. Although there has been much interest in the immunomodulatory properties of MSC and their immunologic reactions following autologous, allogeneic and xenogenic transplantation of MSC in vivo, up to date, the expression of immunogenic markers, such as class I and II human leukocyte antigens (HLA), after differentiation of human umbilical cord blood (hUCB)-derived MSC has been poorly investigated and require extensive in vitro and in vivo testing. In this experiment, the expression of the HLA-ABC and HLA-DR on hUCB-derived MSC have been tested by immunocytochemical staining. The undifferentiated MSC were moderately stained for HLA-ABC but very weakly for HLA-DR. In order to investigate the inhibitory effect of allogeneic lymphocytes on proliferation of MSC, the MSC were cultured in the presence or absence of peripheral allogeneic lymphocytes stimulated with concanavalin A. The allogeneic lymphocytes did not significantly inhibit MSC proliferation. We conclude that hUCB-MSC expressed moderately class I HLA antigen while almost negatively class II HLA antigen. The MSC have an immunomodulatory effect which can suppress the allogeneic response of lymphocytes. These in vitro data suggest that allogeneic MSC derived from cord blood can be useful candidate for allogeneic cell therapy and transplantation without a major risk of rejection.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.3
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• pp.291-301
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• 2021

The aim of this study is to compare the properties of odontoblast gene of early passage cells and late passage cells derived from impacted maxillary supernumerary teeth. Impacted supernumerary teeth with maxilla were extracted from 12 patients (8 males, 4 females) between 6 - 9 years old without medical history. Real-time polymerase chain reaction (PCR) was conducted to compare characterization of odontoblast cell in the 3rd and 10th passage, and between with bone inducing additive group and without additive group. Genes for odontoblasts characteristics are osteonectin (ONT), alkaline phosphatase (ALP), osteocalcin (OCN), dentin matrix protein 1 (DMP-1) and dentin sialophosphoprotein (DSPP). The level of gene expression was in a decreasing order of ONT, ALP, OCN, DMP-1 and DSPP in the 3rd passage, and in decreasing order of ONT, DMP-1, OCN, ALP, and DSPP in the 10th passage in the undifferentiation and differentiation group. The order of ONT, DMP-1, and OCN did not changed. ALP and DMP-1 were switched in order. ALP and DMP-1 may be used as important markers for differentiating between the 3rd passage and 10th passage cells. Considering that supernumerary tooth was extracted young age and the time required to cultured 10th passage was short, supernumerary tooth can be considered a useful donor site of dental pulp stem cells.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.243-249
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• 2010

Tissue engineered bone (TEB) can replace an autogenous bone graft requiring an secondary operation site as well as avoid complications like inflammation or infection from xenogenic or synthetic bone graft. Adult mesenchymal stem cells (MSC) for TEB are considered to have various ranges of differentiation capacity or multipotency by the donor site and age. This study examined the effect of age on proliferation capacity, differentiation capacity and bone morphogenetic protein-2 (BMP-2) responsiveness of human bone marrow stromal cells (hBMSC) according to the age. In addition, to evaluate the effect on enhancement for osteoblast differentiation, the hBMSC were treated with Trichostatin A (TSA) and 5-Azacitidine (5-AZC) which was HDAC inhibitors and methyltransferase inhibitors respectively affecting chromatin remodeling temporarily and reversibly. The young and old group of hBMSC obtained from the iliac crest from total 9 healthy patients, showed similar proliferation capacity. Cell surface markers such as CD34, CD45, CD90 and CD105 showed uniform expression regardless of age. However, the young group showed more prominent transdifferentiation capacity with adipogenic differentiation. The osteoblast differentiation capacity or BMP responsiveness was low and similar between young and old group. TSA and 5-AZC showed potential for enhancing the BMP effect on osteoblast differentiation by increasing the expression level of osteogenic master gene, such as DLX5, ALP. More study will be needed to determine the positive effect of the reversible function of HDAC inhibitors or methyltransferase inhibitors on enhancing the low osteoblast differentiation capacity of hBMSC.

• International Journal of Oral Biology
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• v.38 no.3
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• pp.111-119
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• 2013

Objective. To investigate the effects of the hypoxia inducible factor-1 (HIF-1) activation-mimicking agent cobalt chloride ($CoCl_2$) on the osteogenic differentiation of human mesenchymal stem cells (hMSCs) and elucidate the underlying molecular mechanisms. Study design. The dose and exposure periods for $CoCl_2$ in hMSCs were optimized by cell viability assays. After confirmation of $CoCl_2$-induced HIF-$1{\alpha}$ and vascular endothelial growth factor expression in these cells by RT-PCR, the effects of temporary preconditioning with $CoCl_2$ on hMSC osteogenic differentiation were evaluated by RT-PCR analysis of osteogenic gene expression, an alkaline phosphatase (ALP) activity assay and by alizarin red S staining. Results. Variable $CoCl_2$ dosages (up to $500{\mu}M$) and exposure times (up to 7 days) on hMSC had little effect on hMSC survival. After $CoCl_2$ treatment of hMSCs at $100{\mu}M$ for 24 or 48 hours, followed by culture in osteogenic differentiating media, several osteogenic markers such as Runx-2, osteocalcin and osteopontin, bone sialoprotein mRNA expression level were found to be up-regulated. Moreover, ALP activity was increased in these treated cells in which an accelerated osteogenic capacity was also verified by alizarin red S staining. Conclusions. The osteogenic differentiation potential of hMSCs could be preserved and even enhanced by $CoCl_2$ treatment.