• Horticultural Science & Technology
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• v.33 no.1
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• pp.18-23
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• 2015

Time-specific responses of flower bud differentiation were investigated in 'Shinko' (Pyrus pyrifolia Nakai) pear grown at different altitudes from July through December 2013 to determine their suitability as scions in a top-grafting system. Flower bud initiation and bud necrosis were monitored on each of three sections of one-year-old shoots: terminal, middle, and basal. Flower bud differentiation s tarted in September in the highlands of the Lishan area, and in J uly in the lowlands of the Zhoulan area. In Lishan, flower bud differentiation was higher in the middle and basal segments; during leaf fall, however, flower bud differentiation occurred rapidly in the terminal segment. In Zhoulan, flower buds began to differentiate from the terminal section of the shoot, and severe flower bud necrosis was noted. In July, flower buds developed normally; however, in early August, some of the buds at the basal segment showed browning. During leaf fall, some flower buds showed symptoms of necrosis with rapid and complete browning. Flower bud necrosis began at the basal segment and progressed rapidly towards middle and terminal sections. Before leaf fall, flower buds fell off when scales swelled. The terminal and middle parts of the current-year shoots, with some flower buds, collected in October or later from the Lishan area could be used as scions for top-grafting of 'Shinko' pear. Each grafting scion was a 3-5 cm shoot with one flower bud. These results suggest that scions from the terminal and middle segments of stems of 'Shinko' pear from the Lishan area can be used as scions whereas those from Zhoulan area show necrosis and might not be suitable as scions.

• Molecules and Cells
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• v.20 no.1
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• pp.57-68
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• 2005

Murine erythroleukemia (MEL) cells are widely used to study erythroid differentiation thanks to their ability to terminally differentiate in vitro in response to chemical induction. At the molecular level, not much is known of their terminal differentiation apart from activation of adult-type globin gene expression. We examined changes in gene expression during the terminal differentiation of these cells using microarray-based technology. We identified 180 genes whose expression changed significantly during differentiation. The microarray data were analyzed by hierarchical and k-means clustering and confirmed by semi-quantitative RT-PCR. We identified several genes including H1f0, Bnip3, Mgl2, ST7L, and Cbll1 that could be useful markers for erythropoiesis. These genetic markers should be a valuable resource both as potential regulators in functional studies of erythroid differentiation, and as straightforward cell type markers.

• Natural Product Sciences
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• v.14 no.3
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• pp.182-186
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• 2008

Scutellaria baicalensis Georgi (SBG) is traditionally used medicinal herb that has anti-oxidant, anticancer and anti-inflammatory effects. In this study, we investigated whether the extracts of SBG have the inhibitory activity in the osteoclast differentiation by using mouse monocytes RAW264.7 cells and primary mouse bone marrow-derived macrophages (BMMs). Methanol extract (ME) from SBG was successively fractionated into methylene chloride (MF), ethylacetate (EF) and n-butanol fraction (BF). The activity assay for tartrateresistant acid phosphatase (TRAP) and Western blot analysis were employed to evaluate the osteoclasts differentiation and the activation of mitogen-activated protein (MAP) kinases, respectively. ME, MF, EF and BF significantly and dose-dependently inhibited osteoclast differentiation without the decrease of cell viability at the concentrations used in this study. In addition, ME significantly inhibited the activation of c-jun-N-terminal kinase (JNK). In conclusion, this study firstly demonstrated that ME of SBG has the potential to inhibit the osteoclast differentiation through the suppression of JNK activation partially.

• Animal cells and systems
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• v.1 no.2
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• pp.323-328
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• 1997

We have previously shown that chick muscle extracts contained at least 10 different ubiquitin C-terminal hydrolases (UCHs). In the present studies, one of the enzymes, called UCH-9, was purified by conventional chromatographic procedures using $^{125}l$-labeled ubiquitin-${\alpha}$NH-MHISPPEPESEEEEE HYC (Ub-PESTc) as a substrate. The purified enzyme behaved as a 27-kDa protein under both denaturing and nondenaturing conditions, suggesting that it consists of a single polypeptide chain. It was maximally active at pHs between 7 and 8.5, but showed little or no activity at pH below 6 and above 10. Lice other UCHs, its activity was strongly inhibited by sulfhydryl blocking reagents, such as iodoacetamide, and by Ub-aldehyde. In addition to Ub-PESTc, UCH-9 hydrolyzed Ub-aNH-protein extensions, including Ub-${\alpha}NH$-carboxyl extension protein of 80 amino acids and Ubo-${\alpha}NH$-dihydrofolate reductase. However, this enzyme was not capable of generating free Ub from mono-Ub-${\varepsilon}NH$-protein conjugates and from branched poly-Ub chains that are ligated to proteins through ${\varepsilon}NH$-isopeptide bonds. This enzyme neither could hydrolyze poly-His-tagged di-Ub. These results suggest that UCH-9 may play an important role in production of free Ub and ribosomal proteins from their conjugates.

• Journal of Navigation and Port Research
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• v.30 no.4
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• pp.277-283
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• 2006

It is a world trend to construct large terminal and develop automated container terminal to attract Super Post-Panamax and provide service which is based on differentiation. In fact, there is insufficient research for automatization of terminal gate since the automatization of current constructed container terminal is only focused on increasing productivity and unmanned system through the automatization of quay, yard, etc. In this paper, we have investigated advantage/disadvantage of existing gate operation systems and compared each gate operation system in the aspect of raising terminal image and the productivity. For the specific study, we have used data from actual terminal gate operation and RFID model business sponsored by MOMAF (Ministry of Maritime Affairs and Fisheries). As a result, this paper carried out an efficient gate operation system and it has been expected that it will be performed as groundwork of automated gate operation system which is for design of container terminal and improvement of gate operation system.

• Toxicological Research
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• v.22 no.3
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• pp.283-291
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• 2006

The survival and growth of epithelial cells depends on adhesion to the extracellular matrix. An adhesion signal may regulate the initiation of differentiation, since epidermal keratinocytes differentiate as they leave the basement membrane. A metabolically dead cornified cell envelope is the end point of epidermal differentiation so that this process may be viewed as a specialized form of programmed cell death. In order to investigate the precise cellular signaling events loading to terminal differentiation of keratinocytes, we have utilized HaCaT cells to monitor the biological consequences of $Ca^{2+}$ stimulation and numerous downstream signaling pathways, including activation of the extracellular signal-regulated protein kinase(ERK) pathway and activation of phosphatidylinositol 3-kinase(PI3K). The results presented in this study show that $Ca^{2+}$ function as potent agents for the differentiation of HaCaT keratinocytes, and this differentiation depends or the activation of ERK, Protein kinase B(PKB) and p70 ribosomal protein S6 kinase(p70S6K). Finally, the results show that the expression of Activator protein 1(AP-1; c-Jun and c-Fos) increased following $Ca^{2+}$-mediated differentiation of HaCaT cells, suggesting that ERK-mediated AP-1 expression is critical for initiating the terminal differentiation of keratinocytes.

• The Korea Genome Conference
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• 2005.09a
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• pp.54-54
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• 2005

• Molecules and Cells
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• v.21 no.2
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• pp.294-301
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• 2006

We have previously reported that phosphorylation of eukaryotic elongation factor 2 (eEF2) is related to the differentiation of chick embryonic muscle cells in culture. In the present study, we found that eEF2 phosphorylation declined shortly after induction of differentiation of L6 myoblasts, when the cells prepare for terminal differentiation by withdrawing from the cell cycle. This decrease in phosphorylation was prevented by inhibitors of phosphoinositide 3-kinase (PI3-kinase) that strongly inhibit myoblast differentiation. We hypothesized that PI3-kinase plays an important role in myoblast differentiation by regulating eEF2 phosphorylation in the early stages of differentiation. To test this hypothesis, myoblasts were synchronized at in $G_2/M$ and cultured in fresh differentiation medium (DM) or growth medium (GM). In DM the released cells accumulated in $G_0$/$G_1$ while in GM they progressed to S phase. In addition, cyclin D1 was more rapidly degraded in DM than in GM, and eEF2 phosphorylation decreased more. Inhibitors of PI3-kinase increased eEF2 phosphorylation, but PI3-kinase became more activated when eEF2 phosphorylation declined. These results suggest that the regulation of L6 myoblast differentiation by PI3-kinase is related to eEF2 phosphorylation.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.102-102
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• 2003

Embryonic stem (ES) cells proliferate extensively in the undifferentiated state and have the potential to differentiate into a variety of cell types in response to various environmental cues. The generation of functional dopaminergic neurons from ES cells is promising for cell replacement therapy to treat Parkinson's disease. We compared the in vitro differentiation potential of pluripotent human embryonic stem (hES, MB03) cells induced with basic fibroblast growth factor (bFGF) or retinoic acid (RA). Both types of treatment resulted in similar neural cell differentiation patterns at the terminal differentiation stage, specifically, 75% neurons and 11% glial cells. Additionally, treatment of hES cells with brain derived neurotrophic factor (BDNF) or transforming growth factor (TGF)- $\alpha$ during the terminal differentiation stage led to significantly increased tyrosine hydroxylase (TH) expression, compared to control (P<0.05). In contrast, no effect was observed on the rate of mature or glutamic acid decarboxylase-positive neurons. Immunostaining and HPLC analyses revealed the higher levels of TH (20.3%) and dopamine in bFGF and TGF-$\alpha$ treated hES cells than in RA or BDNF treated hES cells. The results indicate that TGF-$\alpha$ may be successfully used in the bFGF induction protocol to yield higher numbers of functional dopaminergic neurons from hES cells.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.1
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• pp.19-27
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• 2004

Objective: This study was to examine the in vitro neural cell differentiation patterns of human embryonic stem (hES) cells following treatment of various neurotrophic factors [basic fibroblast growth factor (bFGF), retinoic acid (RA), brain derived neurotrophic factor (BDNF) and transforming growth factor (TGF)-$\alpha$], particulary in dopaminergic neuron formation. Methods: The hES cells were induced to differentiate by bFGF and RA. Group I) In bFGF induction method, embryoid bodies (EBs, for 4 days) derived from hES were plated onto gelatin dish, selected for 8 days in ITSFn medium and expanded at the presence of bFGF (10 ng/ml) for another 6 days followed by a final differentiation in N2 medium for 7, 14 and 21 days. Group II) For RA induction, EBs were exposed of RA ($10^{-6}M$) for 4 days and allowed to differentiate in N2 medium for 7, 14 and 21 days. Group III) To examine the effects of additional neurotrophic factors, bFGF or RA induced cells were exposed to either BDNF (10 ng/ml) or TGF-$\alpha$ (10 ng/ml) during the 21 days of final differentiation. Neuron differentiation and dopamine secretion were examined by indirect immunocytochemistry and HPLC, respectively. Results: The bFGF or RA treated hES cells were resulted in similar neural cell differentiation patterns at the terminal differentiation stage, specifically, 75% neurons and 11% glial cells. Additionally, treatment of hES cells with BDNF or TGF-$\alpha$ during the terminal differentiation stage led to significantly increased tyrosine hydroxylase (TH) expression of a dopaminergic neuron marker, compared to control (p<0.05). In contrast, no effect was observed on the rate of mature neuron (NF-200) or glutamic acid decarboxylase-positive neurons. Immunocytochemistry and HPLC analyses revealed the higher levels of TH expression (20.3%) and dopamine secretion (265.5 $\pm$ 62.8 pmol/mg) in bFGF and TGF-sequentially treated hES cells than those in $\alpha$ RA or BDNF treated hES cells. Conclusion: These results indicate that the generation of dopamine secretory neurons from in vitro differentiated hES cells can be improved by TGF-$\alpha$ addition in the bFGF induction protocol.