• Biomolecules & Therapeutics
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• v.8 no.4
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• pp.285-292
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• 2000

The effects of the members of the same nuclear receptor superfamily (all-trans retinoic acid (RA), thyroid hormone(T3) or hydrocortisone) on proliferation and differentiation in the SK-N-SH neuroblastoma (NB) cell lines were studied. NB cells were treated with RA, T3, or hydrocortisone at concentration of 10$^{-6}$ M or 10$^{-8}$ M for 3 days or 7 days. RA induced concentration- and time-dependent morphologic differentiation(neurite outgrowth and microtubule-associated protein expression) and growth inhibition in NB cells. Treatment of 10$^{-7}$ M T3 for 7 days increased viability and differentiation of NB cells. Treatment of 10$^{-6}$ M hydrocortisone for 7 days increased viability of NB cells. Although these three effectors are members of the same receptor superfamily, the regulation of brain development may be carried out in a different manner.

• YAKHAK HOEJI
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• v.24 no.3_4
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• pp.143-150
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• 1980

The effect of ginseng saponin on chick embryonic dorsal root ganglia organ culture and brain, spinal cord, muscle dissociation cultures was studied. The fiber outgrowth in explanted chick embryonic dorsal root ganglia was markedly induced by water and alcohol extracts of ginseng, total ginseng saponin, protopanaxadiol and protopanaxatriol glycosides as well as ginsenosides R/sub b1/, R/sub d/, R/sub 0/+R/sub a/+R/sub b1/, and R/sub b2/+R/sub c/+R/sub e/ mixtures. The life span of the cultured chick embryonic dorsal root ganglia and potentiation of nerve cell density were also observed with all of these ginseng saponins. The effect of ginseng saponin on chick embryonic dorsal root ganglia organ culture was more marked in the absence of the chick embryonic extract which was known to contain nerve growth factor-like material in the culture media. However, the ginseng saponin did not influence the cultured central nervous system such as brain and spinal cord cells and cultured skeletal muscle cells with respect to the morphological changes, maturation and life span of these cells.

• Molecules and Cells
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• v.41 no.7
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• pp.622-630
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• 2018

Leukocyte common antigen-related protein tyrosine phosphatases (LAR-RPTPs) are cellular receptors of heparan sulfate (HS) and chondroitin sulfate (CS) proteoglycans that regulate neurite outgrowth and neuronal regeneration. LAR-RPTPs have also received particular attention as the major presynaptic hubs for synapse organization through selective binding to numerous postsynaptic adhesion partners. Recent structural studies on LAR-RPTP-mediated trans-synaptic adhesion complexes have provided significant insight into the molecular basis of their specific interactions, the key codes for their selective binding, as well as the higher-order clustering of LAR-RPTPs necessary for synaptogenic activity. In this review, we summarize the structures of LAR-RPTPs in complex with various postsynaptic adhesion partners and discuss the molecular mechanisms underlying LAR-RPTP-mediated synaptogenesis.

• Journal for History of Mathematics
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• v.32 no.3
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• pp.97-108
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• 2019

This paper is an outgrowth of a study on recent papers and presentations of Hong Sung Sa, Hong Young Hee and/or Lee Seung On on Gugo Wonlyu which is believed to be written by the famous Joseon scholar Jeong Yag-yong. Most of what is discussed here is already explained in these papers and presentations but due to brevity of the papers it is not understood by most of us. Here we present them in more explicit and mathematical ways which, we hope, will make them more accessible to those who have little background in history of classical Joseon mathematics. We also explain them using elementary projective geometry which allow us to visualize Pythagorean polynomials geometrically.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.304.2-304.2
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• 2002

In central nervous system. matrix metalloproteinases (MMPs) are produced by neuron as well as glia and implicated in physiological events such as neurite outgrowth and myelination etc. In addition. MMPs also contribute to the pathogenesis of several CNS diseases such as multiple sclerosis, Alzheimer's disease and malignant glioma. In spite of their functional importance, little is known about the signal transduction pathways leading to the induction of MMPs in CNS. Here. we investigated whether the activation of Erk(1/2) is involved in the induction of MMP-9 in LPS-stimulated primary astrocytes. (omitted)

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.359-366
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• 2016

Exosome, a small vesicle secreted from cells, has diverse functions depending on cell origins and tissue types and plays a important role in cell viability and intercellular communication. Recently, many researchers have demonstrated the use of exosomes for the treatment of cancers and immune diseases, and the development of diagnostic biomarker. However, the secretion mechanism of exosome from skin cell and its physiological functions in skin remain unclear. Thus, this study aimed to explore whether keratinocyte-derived exosome affects proliferation and migration in HaCaTs. Exosomes were isolated from HaCaTs by ExoQuick-TC and then boiled or unbolied. Boiled and unboiled exosome induced proliferation in HaCaTs in a dose-dependant manner ($0.1{\sim}20{\mu}g/mL$), respectively. Boiled and unboiled exosome at concentration of $20{\mu}g/mL$ increased proliferation level in HaCaTs by $186.96{\pm}3.87%$ and $193.48{\pm}10.48%$ compared with control group. Unboiled exosome stimulated migration in HaCaTs in a dose-dependent manner ($0.1{\sim}20{\mu}g/mL$), which reached a maxium at concentration of $20{\mu}g/mL$ ($179.39{\pm}4.89%$ of control), but boiled exosome did not affect HaCaT migration. In addition, unboiled exosome ($0.1{\sim}20{\mu}g/mL$) dose-dependently stimulated sprout outgrowth in HaCats. These results demonstrate that in exosome from HaCaTs, heat-stable components such as lipid may induce HaCaT proliferation and heat-unstable components such as protein may stimulate migration and sprout outgrowth in HaCaTs, thereby leading to reepithelialization and skin-wound healing activities. It is concluded that exosomes from HaCaTs may be used as cosmetic materials.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.6
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• pp.1444-1448
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• 2008

Down-regulation of melanin synthesis is required for recovery of pigmentary disorders and it is well known that ${\alpha}$-MSH induced melanin synthesis and dendrite outgrowth on melanocytes. This study was conducted to evaluate the depigmenting properties of ethanol extract from a Lavandula vera. The ethanol extract from Lavandula vera inhibited melanin contents and tyrosinase activity in a dose-dependent manner, compared with untreated group. Treatment of the ethanol extract of Lavandula vera effectively suppressed the ${\alpha}$-MSH-stimulated melanin formation, tyrosinase activity and dendrite outgrowth. Moreover, the ${\alpha}$-MSH-induced mRNA expression of tyrosinase was significantly attenuated by Lavandula vera treatment. These results suggest that Lavandula vera exerts its depigmenting effects through the suppression of tyrosinase and cytoplasmic dendricity. And it may be a potent depigmetation agent in hyperpigmentation condition.

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.135-141
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• 2010

Embryoid bodies (EBs) generated from human embryonic stem cells (hESCs) include spontaneously induced endodermal lineage cells (ELCs). Activin-A plays important roles in the endoderm differentiation of hESCs. Despite studies on the generation of ELCs from hESCs with treatment of Actvin-A, it was unclear for localization and pattern of ELCs by Activin-A during differentiation of hESCs. Accordingly in this study, we knew that Actvin-A increased the cystic EBs formation, including the highly enriched AFP (endoderm lineage specific marker)-expressing cells in the surface of cystic EBs. To induce the EBs formation from undifferentiated hESCs, cells were transferred onto petri-dish and cultured in suspension condition without bFGF removed hESC media (EB media) for 3 days. Next to investigate the effect of Activin-A, EBs were subsequently cultured in EB media supplement with 100 ng/ml Activin-A for 3 days. After 5~7 days of Activin-A treatment, cystic EBs began to appear which increased in numbers reaching ~60% of initially formed EBs over 5 days. Endoderm lineage marker, AFP were highly expressed and specifically localized at the surface region of cystic EBs comparison with normal EBs. We next attached the cystic EBs onto gelatin-coated plates and cultured for 5 days. In the results of real-time PCR and immunocytochemistry analysis, AFP-expressing cells migrated and localized at the outgrowth region of attached cystic EBs. To obtain the AFP-expressing cells of the outgrowth region, we manually isolated by using micro-dissection and cultured them. These cells strongly express AFP over 70% of isolated cells post re-plating. Here, we first showed an expression pattern of specifically localized ELCs by Activin-A during differentiation of hESCs. From this observation, we could highly purified ELCs from undifferentiated hESCs. Taken together, our system will provide a novel and efficient option to generate ELCs from hESCs.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.2
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• pp.507-516
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• 2004

Alzheimer's disease(AD) is a geriatric dementia that is widespread in old age. In the near future AD will be the commom disease in public health service. Although a variety of oriental presciptions in study POD(Polygala tenuifolia extracted from dichlorometan) have been traditionally utilized for the treatment of AD, their pharmacological effects and action mechanisms have not yet fully elucidated. It has been widely believed that AP peptide divided from APP causes apoptotic neurotoxicity in AD brain. However, recent evidence suggests that CT105, carboxy terminal 105 aminoacids peptide fragment of APP, may be an important factor causing neurotoxicity in AD. SK-N-SH cells expressed with CT105 exhibited remarkable apoptotic cell damage. Based on morphological observations by phase contrast microscope and NO formation in the culture media, the CT105-induced cell death was significantly inhibited by POD. In addition, AD is one of brain degeneration disease. So We studied on herbal medicine that have a relation of brain degeneration. From old times, In Oriental Medicine, PO water extract has been used for disease in relation to brain degeneration. We were examined by ROS formation, neurite outgrowth assay and DPPH scravage assay. Additionally, we investigated the association between the CT105 and neurite degeneration caused by CT105-induced apoptotic response in neurone cells. We studied on the regeneratory and inhibitory effects of anti-Alzheimer disease in pCT105-induced neuroblastoma cell lines by POD. Findings from our experiments have shown that POD inhibits the synthesis or activities of CT105, which has neurotoxityies and apoptotic activities in cell line. In addition, treatment of POD(>50 ㎍/㎖ for 12 hours) partially prevented CT(105)-induced cytotoxicity in SK-N-SH cell lines, and were inhibited by the treatment with its. POD(>50 ㎍/㎖ for 12 hours) repaired CT105-induced neurite outgrowth when SK-N-SH cell lines was transfected with CT105. As the result of this study, In POD group, the apoptosis in the nervous system is inhibited, the repair against the degerneration of Neuroblastoma cells by CT105 expression is promoted. Decrease of memory induced by injection of scopolamin into rat was also attenuted by POD, based on passive avoidance test. Taken together, POD exhibited inhibition of CT105-induced apoptotic cell death. POD was found to reduce the activity of AchE and induced about the CA1 in rat hippocampus. Base on these findings, POD may be beneficial for the treatment of AD.

• Journal of Life Science
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• v.30 no.6
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• pp.513-521
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• 2020

B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi1) is a polycomb group protein and a core component of polycomb repressive complex 1. Initial research into Bmi1 has focused on its role in tumorigenesis, and it is generally accepted that it is important for the proliferation and survival of cancer cells. However, more recent studies have revealed that Bmi1 is downregulated in brains with neurodegenerative disease and that it regulates the function of mitochondria and reactive oxygen species levels. In this study, we tested the therapeutic potential of Bmi1 in pilocarpine-induced seizures in Bmi1-knockout mice. Bmi1 expression transiently increased in the hippocampal CA1 and CA3 and the dentate gyrus following pilocarpine-induced status epilepticus (SE). In terms of seizure behavior, SE induction was 43.14% and 53.57% for Bmi1^+/+ and Bmi1^+/- mice, respectively. However, there was no significant difference in mortality or hippocampal damage between the two groups. Two months after SE induction, the frequency of epileptic seizures in the Bmi1^+/- mice was 50% lower than in the control group, although the difference was not statistically significant. In addition, mossy fiber outgrowth in the Bmi1^+/- mice was significantly higher than in their wild-type littermates. Taken together, these data indicate that reduced Bmi1 activity increases pilocarpine-induced seizure probability and mossy fiber outgrowth.