• Proceedings of the PSK Conference
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• 2003.10b
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• pp.169.2-170
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• 2003

Erythropietin (EPO), a hematopoietic factor is also required for normal brain development, and its receptor is localized in brain. Therefore, it is possible that EPO could act as a neurotropic factor inducing differentiation of neurons. The present study, we therefore investigated whether EPO can increase differentiation of undifferentiated cortical neuron isolated from postneonatal (Day 1) rat brains and PC12 cell, undifferentiated dopaminagic cell line. EPO dose (1-100 U/ml) dependently increased cell differentiation and expression of differentiation marker gene (neurofilament and tyrosine hydroxylase) in both cells. (omitted)

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.206.1-206.1
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• 2003

The immunomodulator Ginsan has been found previously by us to stimulate the secretion of high levels of IL -1. IL -6 and TNF-alpha in irradiated mice. These cytokines are known to induce proliferation and differentiation of hematopoietic progenitor cells from the spleen and bone marrow and to protect mice from DNA-damaging agents. The present studies were evaluated as a cytoprotective agent against toxicity of the alkylating drugs. (omitted)

• Journal of Acupuncture Research
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• v.23 no.5
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• pp.69-77
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• 2006

Background : Mesenchymal stem cells (MSCs) are present in most of the tissue matrix, taking part in their regeneration when injury or damage occurs. The aim of this study was to investigate the presence of cells with pluripotential characteristics in human subchondral bone and the capacity of these cells to differentiate to osteoblast. Methods : Human subchondral bone were digested with collagenase. Isolated cells were cultured with a-MEM, 15% FBS, 10-8M dexamethasone and 50 ng/mL ascoric acid. Cells from 0 day(isolated cells), 7 day (first subculture) and 14 days (third subculture) were used to carry out phenotypic characterization experiments flowcytometry analysis with 11 monoclonal antibodies) and osteogenic differentiation experiments. Osteogenic differentiation of cells was assessment by quantification of bone extracellular matrix components by following analysis: alkaline phosphatase(ALP) stains to detect ALP activity, RT-PCR and western blot to detect osteocalcin (OCN), osteopontin (OPN) and type I collagen(Col I), and Alizarin red stains to detect calcium deposition. Results : Flowcytometry analyses showed that in our population more than 98% of cells were positive for MSC markers: SH-2(CD105, 99%), CD29 (95%), CD73 (95%). Cells were negative for hematopoietic markers (CD11b, CD34, and CD45). Furthermore, cells showed positive stain to multipotent markers such as CDl17 (c-kit) (15.1%), and CD166 (74.9%), and cell adhesion molecules such as CD54 (78.1%) and CD106 (63.5%). The osteogenic specific marker analyses showed that the culture of these cells for 7 and 14 days stimulates ALP, OCN, OPN and Col I synthesis by RT-PCR and Western blot analysis. Also, after 14 days in the culture of MSCs induces mineralization by Arizarin red stain. Conclusion : In this work, we demonstrated a new and efficient method for osteoblastic differentiation of human subchondral bone stem cells. As MSCs takes part in reparative processes of adult tissues, these cells could play an important role in osteogenesis.

• Environmental Analysis Health and Toxicology
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• v.22 no.1 s.56
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• pp.73-82
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• 2007

Six week-old ICR mite which were divided into four groups including NC, RC, RR and RS were injected with sun ginseng (RS), red ginseng (RR) and saline (RC) intraperitonedlly as an amount of 60 mg/g body weight at 1 hour, 12 hours and 36 hours before the irradiation of high-energy X-ray and the mire were sacrificed at three and a half days after the irradiation. The RS group were significant increase in the weight of spleen (p<0.01) and the numbers of jejunal crypt cells (P<0.01), WBC (p<0.05), lymphocytes (p<0.05) and neutrophils (p<0.05) in comparison with the RC group. The RR group were significant increase in the numbers of jejunal crypt cells (p<0.001), WBC (p<0.05) and neutrophils (p<0.05) in comparison with the RC group. The RS group exhibited a more increase in the weights of spleen and thymus and the numbers of jejunal crypt cells and all items of hematological examination than the RR group. The values of ALT (alanine transaminase) and AST (aspartate transaminase) were significantly elevated (p<0.05) by radiation and they were significantly decreased (p<0.05) in the RS group to the values of the NC group. Taken together the above results, sun ginseng demonstrated a jejunal crypt survival effect, the protective effects on hepatocytes and immune and hematopoietic cells in mice irradiated with high-energy X-ray, and those radiation protective effects were a little higher in comparison with red ginseng.

• Archives of Pharmacal Research
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• v.29 no.3
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• pp.218-223
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• 2006

Erythropoietin (EPO), a hematopoietic factor, is required for normal erythrocyte developments, but it has been demonstrated to have many other functions, and its receptor is localized in other tissues. In the present study, we investigated whether EPO can promote other cell proliferation and possible molecular mechanisms. EPO restored the inhibition of the RAW264.7 and PC12 cell growth by fetal bovine serum (FBS) withdrawal in a dose dependent manner, but not that of other cell types tested. The restoring effect of EPO was completed when the RAW264.7 cells were cultured in the medium containing as low as 3% of FBS, and 10 U/mL EPO could replace FBS. The restoring effect of EPO in the RAW264.7 cells was associated with the increased of c-Fos and c-Jun expression as well as AP-1 activation. These data demonstrate that EPO can stimulate RAW264. 7 cell as well as PC12 cell growth even when the cells were cultured without FBS or in the presence of small amounts of FBS in the medium, and this stimulating effect is associated with the activation of AP-1 transcription factor.

• Journal of Periodontal and Implant Science
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• v.34 no.3
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• pp.489-498
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• 2004

Recent studies have demonstrated that human periodontal ligament cells express receptor activation of nuclear factor ${\kappa}B$ ligand (RANKL) which enhances the bone resorbing activity of osteoclasts differentiated from hematopoietic preosteoclasts. The purpose of this study is to determine the effects of p38 MAPK and JNK kinase upon regulating RANKL and OPG in response to $IL-1{\beta}$(l ng/ml) in rat periodontal ligament cells. Soluble RANKL was measured by immunoassay. The effects of p38 MAPK on RANKL and OPG expression was determined by RT-PCR. The results were as follows: 1. Periodontal ligament cells which stimulated by $IL-1{\beta}$ increased soluble RANKL synthesis by dose-dependent pattern. 2. p38 MAP kinase inhibitor (SB203580) showed regulation of soluble RANKL expression by dose-dependent manners. 3. p38 MAP kinase inhibitor (SB203580) regulated the expression of RANKL, but it dose regulate the expresseion of OPG. 4. JNK (c-jun $NH_2-terminal$ kinase) inhibitor (PD98059) did not regulate mRANKL and mOPG. These results suggested that p38 MAPK play a significant role in RANKL gene expression.

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.280-285
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• 2012

The developing embryo naturally experiences relatively low oxygen conditions in vivo. Under in vitro hypoxia, mouse embryonic stem cells (mESCs) lose their self-renewal activity and display an early differentiated morphology mediated by the hypoxia-inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$). Previously, we demonstrated that histone deacetylase (HDAC) is activated by hypoxia and increases the protein stability and transcriptional activity of HIF-$1{\alpha}$ in many human cancer cells. Furthermore HDAC1 and 3 mediate the differentiation of mECSs and hematopoietic stem cells. However, the role of HDACs and their inhibitors in hypoxia-induced early differentiation of mESCs remains largely unknown. Here, we examined the effects of several histone deacetylase inhibitors (HDACIs) on the self-renewal properties of mESCs under hypoxia. Inhibition of HDAC under hypoxia effectively decreased the HIF-$1{\alpha}$ protein levels and substantially improved the expression of the LIF-specific receptor (LIFR) and phosphorylated-STAT3 in mESCs. In particular, valproic acid (VPA), a pan HDACI, showed dramatic changes in HIF-$1{\alpha}$ protein levels and LIFR protein expression levels compared to other HDACIs, including sodium butyrate (SB), trichostatin A (TSA), and apicidin (AP). Importantly, our RT-PCR data and alkaline phosphatase assays indicate that VPA helps to maintain the self-renewal activity of mESCs under hypoxia. Taken together, these results suggest that VPA may block the early differentiation of mESCs under hypoxia via the destabilization of HIF-$1{\alpha}$.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.2
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• pp.82-86
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• 2006

Leukemia arises in hematopoietic progenitor cells and is characterized by impaired or blocked differentiation, uncontrolled proliferation and resistance to apoptosis. Molecular mechanisms underlying cellular functions by $As_2O_3$, however, have been poorly investigated. The consensus of several reports is that $As_2O_3$ induces apoptosis in leukemia cells by activating genes for apoptosis. The present study aimed to investigate the effects of $As_2O_3$ on the cell cycle and its morphological change and a relationship between the caspase-3 and $As_2O_3$-induced apoptosis. Caspase-3 is involved in $As_2O_3$-induced apoptosis in K562 cells. In this study, to address whether $As_2O_3$-induced apoptosis is mediated by caspase-3 activity, the same samples were probed with a specific antibody. The pretreatment of $25{\mu}M$ Z-VAD-fmk, a specific inhibitor of caspase, decreased $As_2O_3$-induced cytotoxicity. And $As_2O_3$ significantly increased the percentages of the cells accumulated in the G2/M phase of the cell cycle in a time- and dose-dependent manner. Chromatin condensational changes were observed with Hoechst 33258 staining after treatment of $As_2O_3$. It was shown that $As_2O_3$-induced apoptosis is controlled through caspase-3 activation. These results may provide a useful rationale for CML treatment.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.5
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• pp.385-391
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• 2011

Purpose: The periosteum is a well-known source of osteogenic precursor cells for tissue-engineered bone formation. However, cultured endothelial or endothelial-like cells derived from periosteum have not yet been investigated. This study focused on endothelial-like cell culture from the periosteum. Methods: Periosteal tissues were harvested from the mandible during surgical extraction of lower impacted third molars. The tissues were treated with 0.075% type I collagenase in phosphate-buffered saline (PBS) for 1 hr at $37^{\circ}C$ to release cellular fractions. The collagenase was inactivated with an equal volume of DMEM/10% fetal bovine serum (FBS) and the infranatant was centrifuged for 10 min at 2,400 rpm. The cellular pellet was filtered through a $100{\mu}m$ nylon cell strainer, and the filtered cells were centrifuged for 10 min at 2,400 rpm. The resuspended cells were plated into T25 flasks and cultured in endothelial cell basal medium (EBM)-2. Results: Among the hematopoietic markers, CD146 was more highly expressed than CD31 and CD34. The periosteal-derived cells also expressed CD90 and CD166, mesenchymal stem cell markers. Considering that the expression of CD146 was constant and that the expression of CD90 was lower at passage 5, respectively, the CD146 positive cells in passage 5 were isolated using the magnetic cell sorting (MACS) system. These CD146 sorted, periosteal-derived cells formed tube-like structures on Matrigel. The uptake of acetylated, low-density lipoprotein, labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI-Ac-LDL) was also examined in these cells. Conclusion: These results suggest that the CD146-sorted positive cells can be referred to as periosteal-derived CD146 positive endothelial-like cells. In particular, when a co-culture system with endothelial and osteoblastic cells in a three-dimensional scaffold is used, the use of periosteum as a single cell source would be strongly beneficial for bone tissue engineering.

• The korean journal of orthodontics
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• v.25 no.6 s.53
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• pp.715-722
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• 1995

Orthodontic tooth movement in response to orthodontic force results from actions of osteoclasts and osteeoblasts in the cell level. Convincing evidence has now been provided to support the view that osteoclasts are derived from mononuclear cells that originate in the bone marrow or other hematopoietic organs and they migrate to the bones via vascular routes. Nitric oxide(NO), which accounts for the biological properties of endothelium-derived relaxing factor(EDRF), is the endogenous stimulator of soluble guanylate cylase. The discovery of the formation of nitric oxide(NO) from L-arginine in mammalian tissues and its biological roles has, in the last 7 years, thrown new light onto many areas of research. Data from experiments in vitro showed that N-metyl-L-arginine(L-NMA) and L-nitro-L- arginine(L-NAME) are competitive inhibitors of nitric oxide synthase. This study suggest that the multinucleated cells in our culture have characteristics of osteoclasts and that the potential bone cell activity of nitric oxide in vitro may be mediated in part by stimulation of marrow mononuclear cells to form osteoclast-like cells. Bone marrow cells were obtaineed from tibia of 19-days old chick embryo. After sacrifice, tibia was quickly dissected and the bone were then split to expose the medullary bone. The cells were attached for 4 hours and the nonadherent cells were collected. Marrow cells weere cultured in 96-well plate in medium 199. To examine the number of TRAP-positive multinucleated cells(MNCs), $10^{-8}\;M\;Vit=D_3$ and various concentration of L-NMA and L-NAME weere added at the beginning of cultures and with each medium change. After 7 days of culture. tartrate-resistant acid phosphatase(TRAP) staining was performed for microscopic evaluation. Cells haying more than three nuclei per cell were counted as MNCs. The obsrved results were as follows;1. 1,25-dihydroxyvitamine $D_3$ stimulated the osteoclast-like multinucleated cells in cultures of chick embryo bone marrow. 2. Nitric oxide synthase inhibitors(NOSI ; N-NMA, N-NAME) stimulated the osteoclast-like cells in cultures of chick embry bone marrow. 3. 1,25-dihydroxyvitamine$D_3$ and nitric oxide synthase inhibitors did not appear to have additive effect on the generation of TRAP-positive MNCs. These results suggest that nitric oxide synthase inhibitors may stimulate the osteoclast-like multinucleated cell formation and fusion in cultures of chick bone marrow.