• Reproductive and Developmental Biology
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• v.35 no.4
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• pp.503-510
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• 2011

Cellular uptake of nanoparticles for stem cell labeling and tracking is a critical technique for biomedical therapeutic applications. However, current techniques suffer from low intracellular labeling efficiency and cytotoxic effects, which has led to great interest in the development of a new labeling strategy. Using silica-coated nanoparticles conjugated with rhodamine B isothiocyanate (RITC) (SR), we tested the cellular uptake efficiency, biocompatibility, proliferation or differentiation ability with murine bone marrow derived hematopoietic stem/progenitor cells. The bone marrow hematopoietic cells showed efficient uptake with SR with dose or time dependent manner and also provided a higher uptake on hematopoietic stem/progenitor cells. Biocompatibility tests revealed that the SR had no deleterious effects on cell cytotoxicity, proliferation, or multi-differentiation capacities in vitro and in vivo. SR nanoparticles are advantageous over traditional labeling techniques as they possess a high level of cellular internalization without limiting the biofunctionality of the cells. Therefore, SR provides a useful alternative for gene or drug delivery into hematopoietic stem/progenitor cells for basic research and clinical applications.

• Reproductive and Developmental Biology
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• v.29 no.2
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• pp.109-115
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• 2005

Hematopoietic stem cells (HSC) are multipotent cells that reside in the bone marrow and replenish all adult hematopoietic lineages throughoutthe lifetime. In this study, we analyzed the expression of receptors of $P2Y_{10}$, purinergic receptor families in murine hematopoietic stem cells, hematopoietic progenitor cells. In addition, the biological activity of $P2Y_{10}$ was investigated with B lymphocyte cell line, Ba/F3 in effect to cell growth and cell cycle. From the analysis of expression in hematopoieticstem cell. and progenitor with RT-PCR, $P2Y_{10}$ was strongly expressed in murine hematopoieticstem cells (c-kit+ Sca-l+ Lin-) and progenitor cell population, such as c-kit- Sca-l+ Lin-, c-kit+ Sca-l- Lin- and c-kit- Sca-l- Lin-. To investigate the biological effects by $P2Y_{10}$, retroviral vector from subcloned murine $P2Y_{10}$ cDNA was used fur gene introduction into Ba/F3 cells, and stable transfectant cells were obtained by flow cytometry sorting. In cell proliferation assay, the proliferation ability of $P2Y_{10}$ receptor gene­transfected cells was strongly inhibited, and the cell cycle was arrested at G1 phase. These result suggest that the $P2Y_{10}$ may be involved the biological activity in hematopoietic stem cells and immature B lymphocytes.

• YAKHAK HOEJI
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• v.49 no.3
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• pp.205-211
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• 2005

The 3' UTR (3' untranslated region) plays important roles in controlling gene expression through regulating 3' polyadenylation, mRNA export, subcellular localization, translational efficiency, and mRNA stability. Changes in the 3' UTR sequence in an expressed transcript can result in functional changes of the genes that are expressed in pathological conditions compared with those genes expressed in normal physiologic conditions. A genome-wide survey of 3' UTR variation was performed for the genes expressed during hematopoietic differentiation from CD34+ stem/progenitor cells to CD 15 + myeloid progenitor cells. Wide-spread differential usage of the 3' UTR was observed from the genes expressed during this cellular transition. This study implies that the 3' UTR can be a highly coordinated region for post-transcriptional regulation of the function of expressed genes.

• Molecules and Cells
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• v.24 no.3
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• pp.343-350
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• 2007

Mesenchymal stem/progenitor cells (MPCs) were isolated from porcine umbilical cord blood (UCB) and their morphology, proliferation, cell cycle status, cell-surface antigen profile and expression of hematopoietic cytokines were characterized. Their capacity to differentiate in vitro into osteocytes, adipocytes and chondrocytes was also evaluated. Primary cultures of adherent porcine MPCs (pMPCs) exhibited a typical fibroblast-like morphology with significant renewal capacity and proliferative ability. Subsequent robust cell growth was indicated by the high percentage of quiescent (G0/G1) cells. The cells expressed the mesenchymal surface markers, CD29, CD49b and CD105, but not the hematopoietic markers, CD45 and CD133 and synthesized hematopoietic cytokines. Over 21 days of induction, the cells differentiated into osteocytes adipocytes and chondrocytes. The expression of lineage specific genes was gradually upregulated during osteogenesis, adipogenesis and chondrogenesis. We conclude that porcine umbilical cord blood contains a population of MPCs capable of self-renewal and of differentiating in vitro into three classical mesenchymal lineages.

• BMB Reports
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• v.50 no.3
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• pp.138-143
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• 2017

Ovariectomy-induced bone loss is related to an increased deposition of osteoclasts on bone surfaces. We reported that the 36-amino-acid-long neuropeptide Y (NPY) could mobilize hematopoietic stem/progenitor cells (HSPCs) from the bone marrow to the peripheral blood by regulating HSPC maintenance factors and that mobilization of HSPCs ameliorated low bone density in an ovariectomy-induced osteoporosis mouse model by reducing the number of osteoclasts. Here, we demonstrated that new NPY peptides, recombined from the cleavage of the full-length NPY, showed better functionality for HSPC mobilization than the full-length peptide. These recombinant peptides mediated HSPC mobilization with greater efficiency by decreasing HSPC maintenance factors. Furthermore, treatment with these peptides reduced the number of osteoclasts and relieved ovariectomy-induced bone loss in mice more effectively than treatment with full-length NPY. Therefore, these results suggest that peptides recombined from full-length NPY can be used to treat osteoporosis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.1
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• pp.39-45
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• 2005

Stem cell therapy using mesenchymal stem cells(MSCs) transplantation have been paid attention because of their powerful proliferation and pluripotent differentiating ability. Although umbilical cord blood (UCB) is well known to be a rich source of hematopoietic stem cells with practical and ethical advantages, the presence of mesenchymal stem cells (MSCs) in UCB has been controversial and it remains to be validated. In this study, we examine the presence of MSCs in UCB harvests and the prevalence of them is compared to that of endothelial progenitor cells. For this, CD34+ and CD34- cells were isolated and cultured under the endothelial cell growth medium and mesenchymal stem cell growth medium respectively. The present study showed that ESC-like cells could be isolated and expanded from preterm UCBs but were not acquired efficiently from full-terms. They expressed CD14-, CD34-, CD45-, CD29+, CD44+, CD105+ cell surface marker and could differentiate into adipogenic and osteogenic lineages. Our results suggest that MSCs are fewer in full-term UCB compared to endothelial progenitor cells.

• Journal of Ginseng Research
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• v.25 no.2
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• pp.63-67
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• 2001

We previously reported that acidic polysaccharide from Panax ginseng induced the proliferation lymphocytes and the generation of activated killer cells. Here we found that polysaccharide (PG-75) precipitated with 75% EtOH from water extract of Panax ginseng also has both in vitron and in vivo hematopoietic activities. In vitro studied with bone marrow cells from BALB/c mouse revealed that PG-75 had direct effect on hematopoietic colony-forming cell(CFC) growth, increased granulocyte macrophage-colony forming cell numbers by 1.59 fold over than non-treated. the ability of PG-75 to modulate hematopoiesis in vivo was evaluated the bone marrow and spleen celluarity, granulocyte-macrophage progenitor cells. BALB/c female mice were administered G-75 intraperitoneally, PG-75 was found to significantly increase the number of BM cells, spleen cells, GM-CFU on 3 hours after injection. PG-75 was also able to induce significant augmentation of GM-CSF and IFN-${\gamma}$, production in sera. These studies illustrate than PG-75 has hematopoietic activities and that this agent may be useful in the prevention and/or treatment of radio- or chemotherapy-associated myelosuppression.

• Molecules and Cells
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• v.21 no.3
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• pp.343-355
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• 2006

Stem cells are unique cell populations with the ability to undergo both self-renewal and differentiation, although a wide variety of adult stem cells as well as embryonic stem cells have been identified and stem cell plasticity has recently been reported. To identify genes implicated in the control of the stem cell state as well as the characteristics of each stem cell line, we analyzed the expression profiles of genes in human embryonic, hematopoietic ($CD34^+$ and $CD133^+$), and mesenchymal stem cells using cDNA microarrays, and identified genes that were differentially expressed in specific stem cell populations. In particular we were able to identify potential hESC signature-like genes that encode transcription factors (TFAP2C and MYCN), an RNA binding protein (IMP-3), and a functionally uncharacterized protein (MAGEA4). The overlapping sets of 22 up-regulated and 141 down-regulated genes identified in this study of three human stem cell types may also provide insight into the developmental mechanisms common to all human stem cells. Furthermore, our comprehensive analyses of gene expression profiles in various adult stem cells may help to identify the genetic pathways involved in self-renewal as well as in multi-lineage specific differentiation.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.1
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• pp.7-11
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• 2004

Leukotactin-1 (Lkn-1), a human CC chemokine, has been demonstrated to induce chemotaxis of neutrophils, monocytes, eosinophils and Iym phocytes and has been shown to suppress colony formation of hematopoietic stem and progenitor cells (HSPC) in vitro and in vivo. The temporal suppression of HSPC by chemokines could potentially be applicable for various indications, such as the protection of HSPC from the several anti-proliferating chemotherapeutics in cancer treatments. In order to evaluate the protective effects on myeloid progenitor cells, the recombinant Lkn-1 was produced by Pichia pastoris and tested with cyclophosphamide, cytotoxic chemotherapeutics. The pretreatment of Lkn-1 increased the number of HSPC in bone marrow as well as the potency of resulting progenitor cells after the treatment of cyclophosphamide. Af-ter the first cycle of cyclophosphamide treatment these protections of HSPC correlated with the increased number of white blood cells and neutrophils in the peripheral blood. In lethal conditions created by the repeated administration of cyclophosphamide, the treatment of Lkn-1 enhanced the survival of mice, suggesting the potential use of Lkn-1 as the protective agent for HSPC from various cytotoxic insults.

• Molecules and Cells
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• v.45 no.3
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• pp.101-108
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• 2022

Drosophila melanogaster lymph gland, the primary site of hematopoiesis, contains myeloid-like progenitor cells that differentiate into functional hemocytes in the circulation of pupae and adults. Fly hemocytes are dynamic and plastic, and they play diverse roles in the innate immune response and wound healing. Various hematopoietic regulators in the lymph gland ensure the developmental and functional balance between progenitors and mature blood cells. In addition, systemic factors, such as nutrient availability and sensory inputs, integrate environmental variabilities to synchronize the blood development in the lymph gland with larval growth, physiology, and immunity. This review examines the intrinsic and extrinsic factors determining the progenitor states during hemocyte development in the lymph gland and provides new insights for further studies that may extend the frontier of our collective knowledge on hematopoiesis and innate immunity.