• BMB Reports
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• v.55 no.6
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• pp.275-280
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• 2022

The treatment of atopic dermatitis (AD) is challenging due to its complex etiology. From epidermal disruption to chronic inflammation, various cells and inflammatory pathways contribute to the progression of AD. As with immunosuppressants, general inhibition of inflammatory pathways can be effective, but this approach is not suitable for long-term treatment due to its side effects. This study aimed to identify a plant extract (PE) with anti-inflammatory effects on multiple cell types involved in AD development and provide relevant mechanistic evidence. Degranulation was measured in RBL-2H3 cells to screen 30 PEs native to South Korea. To investigate the anti-inflammatory effects of Parasenecio auriculatus var. matsumurana Nakai extract (PAE) in AD, production of cytokines and nitric oxide, activation status of FcεRI and TLR4 signaling, cell-cell junction, and cell viability were evaluated using qRT-PCR, western blotting, confocal microscopy, Griess system, and an MTT assay in RBL-2H3, HEK293, RAW264.7, and HaCaT cells. For in vivo experiments, a DNCBinduced AD mouse model was constructed, and hematoxylin and eosin, periodic acid-Schiff, toluidine blue, and F4/80-staining were performed. The chemical constituents of PAE were analyzed by HPLC-MS. By measuring the anti-degranulation effects of 30 PEs in RBL-2H3 cells, we found that Paeonia lactiflora Pall., PA, and Rehmannia glutinosa (Gaertn.) Libosch. ex Steud. show an inhibitory activity of more than 50%. Of these, PAE most dramatically and consistently suppressed cytokine expression, including IL-4, IL-9, IL-13, and TNF-α. PAE potently inhibited FcεRI signaling, which mechanistically supports its basophil-stabilizing effects, and PAE downregulated cytokines and NO production in macrophages via perturbation of toll-like receptor signaling. Moreover, PAE suppressed cytokine production in keratinocytes and upregulated the expression of tight junction molecules ZO-1 and occludin. In a DNCB-induced AD mouse model, the topical application of PAE significantly improved atopic index scores, immune cell infiltration, cytokine expression, abnormal activation of signaling molecules in FcεRI and TLR signaling, and damaged skin structure compared with dexamethasone. The anti-inflammatory effect of PAE was mainly due to integerrimine. Our findings suggest that PAE could potently inhibit multi-inflammatory cells involved in AD development, synergistically block the propagation of inflammatory responses, and thus alleviate AD symptoms.

• Journal of Life Science
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• v.25 no.1
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• pp.101-112
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• 2015

A type of cell junction that is formed between different parts within the same cell is called autotypic cell junction. Autotypic junction proteins form tight junctions found between membrane lamellae of a cell, especially in myelinating glial cells. Some of them have postsynaptic density-95/disks large/zonula occludens-1 (PDZ) domains, which interact with the carboxyl (C)-terminal PDZ-binding motif of other proteins. PDZ domains are protein-protein interaction modules that play a role in protein complex assembly. The PDZ domain, which is widespread in bacteria, plants, yeast, metazoans, and Drosophila, allows the assembly of large multi-protein complexes. The multi-protein complexes act in intracellular signal transduction, protein targeting, and membrane polarization. The identified PDZ domain-containing proteins located at autotypic junctions include zonula occludens-1 (ZO-1), ZO-2, pals-1-associated tight junction protein (PATJ), multi-PDZ domain proteins (MUPPs), membrane-associated guanylate kinase inverted 2 (MAGI2), and protease-activated receptor (PAR)-3. PAR-3 interacts with atypical protein kinase C and PAR-6, forming a ternary complex, which plays an important role in the regulation of cell polarity. MAGI2 interacts with ${\alpha}$-amino-3-hydroxyl-5-methyl-4-isoxazole propionate (AMPA) receptor at excitatory synapses. PATJ is detected in paranodal loops associated with claudin-1. On the other hand, MUPP1 is found in mesaxons and Schmidt-Lanterman incisures with claudin-5. ZO-1, ZO-2, and PAR-3 are found at all three sites. Different distributions of PDZ domain-containing proteins affect the development of autotypic junctions. In this review, we will describe PDZ domain-containing proteins at autotypic tight junctions in myelinating Schwann cells and their roles.

• Molecular & Cellular Toxicology
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• v.4 no.3
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• pp.183-191
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• 2008

Volatile organic compounds (VOCs) are common constituents of cleaning and degreasing agents, paints, pesticides, personal care products, gasoline and solvents. And VOCs are evaporated at room temperature and most of them exhibit acute and chronic toxicity to human. Benzene is the most widely used prototypical VOC and the toxic mechanisms of them are still unclear. The multi-step process of toxic mechanism can be more fully understood by characterizing gene expression changes induced in cells by toxicants. In this study, DNA microarray was used to monitor the expression levels of genes in HepG2 cells and HL-60 cells exposed to the benzene on IC20 and IC50 dose respectively. In the clustering analysis of gene expression profiles, although clusters of HepG2 and HL-60 cells by benzene were divided differently, expression pattern of many genes observed similarly. We identified 916 up-regulated genes and 1,144 down-regulated genes in HepG2 cells and also 1,002 up-regulated genes and 919 down-regulated genes in HL-60 cells. The gene ontology analysis on genes expressed by benzene in HepG2 and HL-60 cells, respectively, was performed. Thus, we found some principal pathways, such as, focal adhesion, gap junction and signaling pathway in HepG2 cells and toll-like receptor signaling pathway, MAPK signaling pathway, p53 signaling pathway and neuroactive ligand-receptor interaction in HL-60 cells. And we also found 16 up-regulated and 14 down-regulated commonly expressed total 30 genes that belong in the same biological process like inflammatory response, cell cycle arrest, cell migration, transmission of nerve impulse and cell motility in two cell lines. In conclusion, we suggest that this study is meaningful because these genes regarded as strong potential biomarkers of benzene independent of cell type.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.253-253
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• 2011

ZnTe semiconductor is very attractive a material for optoelectronic devices in the visible green spectral region because of it has direct bandgap of 2.26 eV. The prototypes of ZnTe light emitting diodes (LEDs) have been reported [1], showing that their green emission peak closely matches the most sensitive region of the human eye. The optoelectronic properties of ZnTe:O film allow to expect a large optical gain in the intermediate emission band, which emission band lies about 0.4-0.6 eV below the conduction band of ZnTe [2]. So, the ZnTe system is useful for the production of high-efficiency multi-junction solar cells [2,3]. In this work, the ZnTe:O thin films were deposited on Al2O3 substrates by using the radio frequency magnetron sputtering system. Three sets of samples were prepared using argon and oxygen as the sputtering gas. The deposition chamber was pre-pumped down to a base pressure of 10-7 Torr before introducing gas. The deposition pressure was fixed at 10-3 Torr throughout this work. During the ZnTe deposition, the substrate temperature was 300 oC. The optical properties were also investigated by using the ultraviolte-visible (UV-Vis) spectrophotometer.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.10
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• pp.1017-1026
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• 2009

The solar cell system operates by facing the sun-light. Minor cracks, static discharge, and thermal shock that can happen during production/testing phase can lead to degradation in performance during operation, since solar cells are exposed to extreme thermal/mechanical environment in space. In order to detect small cracks and internal damages in the solar cells due to thermal shocks, which are the core units of a solar cell system, expensive equipment, complicated test process, and much time are required. Therefore, a qualitative method for easily and quickly testing the 'health' of solar cell functionality is required. This dissertation describes a theoretical and technical grounds for quickly and easily evaluating the health of solar cells using electroluminescence effect of Gallium-Arsenide solar cells that are most widely used by spacecrafts in recent years. Also described in the dissertation is the technical issues and constraining factors for applying the proposed method to actual space-rated solar cell systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.310-316
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• 2021

Conventional satellites are generally large satellites that are multi-functional and have high performance. However, small satellites have been gradually drawing attention since the recent development of lightweight and integrated electric, electronic, and optical technologies. As the size and weight of a satellite decrease, the barrier to satellite development is becoming lower due to the cost of manufacture and cheaper launch. However, solar panels are essential for the power supply of satellites but have limitations in miniaturization and weight reduction because they require a large surface area to be efficiently exposed to sunlight. Space solar cells must be manufactured in consideration of various space environments such as spacecraft and environments with solar thermal temperatures. It is necessary to study structural materials for lightweight and high-efficiency solar cells by applying an unfolding mechanism that optimizes the surface-to-volume ratio. Currently, most products are developed and operated as solar cell panels for space applications with a triple-junction structure of InGaP/GaAs/Ge materials for high efficiency. Furthermore, multi-layered junctions have been studied for ultra-high-efficiency solar cells. Flexible thin-film solar cells and organic-inorganic hybrid solar cells are advantageous for material weight reduction and are attracting attention as next-generation solar cells for small satellites.

• Development and Reproduction
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• v.21 no.3
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• pp.317-325
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• 2017

Direct communication between neighboring cells through connexin (Cx)-based gap junction is a crucial biological manner to regulate functions of a tissue consisting of multi-cell types. The present research evaluated expressional changes of Cx isoforms in the caput epididymis of adult rat exposed to estradiol benzoate (EB) or flutamide (Flu) at the early postnatal age. A single subcutaneous administration of EB at a low-dose [$0.015{\mu}g/kg$ body weight (BW)] or a high-dose ($1.5{\mu}g/kg\;BW$) or Flu at a low-dose ($500{\mu}g/kg\;BW$) or a high-dose (5 mg/kg BW) was performed to an animal at 1 week of age. Quantitative real-time PCR analysis was employed to determine expressional changes of Cx isoforms. The transcript levels of Cxs30.3 and 37 were decreased by a low-dose EB treatment, while decreases of Cxs31, 31.1, 32, 40, and 45 transcript levels were observed with a low-dose EB treatment. The treatment of a high-dose EB resulted in expressional reduction of Cxs30.3, 31, 31.1, 37, 40, 43, and 45. The Flu treatment at a low dose caused increases of Cxs26, 37, and 40 transcript levels but decreases of Cxs31.1, 43, and 45 transcript levels. Increases of Cxs30.3, 31, 37, and 40 mRNA amounts were induced by a high-dose Flu treatment. However, exposure to a high-dose Flu produced expressional decreases of Cxs31.1, 32, and 43 in the adult caput epididymis. These observations suggest that exposure to EB or Flu at the neonatal period could lead to aberrant expression of Cx isoforms in the adult caput epididymis.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.3
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• pp.280-288
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• 2009

In this paper, a high-power and low-loss stripline 10-way power divider is designed and fabricated fur the feed network of an S-band linear array antenna with Chebyshev current distribution which has a narrow beam width and low side lobe level(SLL) of 35 dB or more. The unit cell of the power divider is based on a T-junction power divider and the whole divider is comprised of the cascaded unit cells. The multi-stage impedance transformer and modified ring hybrid are used in designing the power divider for performance improvement. And the reflection loss and insertion loss are improved by modifying a connector structure for a coaxial-to-stripline transition.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.117.2-117.2
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• 2011

Since Gratzel and co-workers developed a new type of solar cell based on the nanocrystalline TiO2 electrode, dye-sensitized solar cells (DSSCs) have attracted considerable attention on account of their high solar energy-to-conversion efficiencies (11%), their easy manufacturing process with low cost production compared to conventional p-n junction solar cells. The mechanism of DSSC is based on the injection of electrons from the photoexcited dye into the conduction band of nanocrystalline TiO2. The oxidized dye is reduced by the hole injection process from either the hole counter or electrolyte. Thus, the electronic structures, such as HOMO, LUMO, and HOMO-LUMO gap, of dye molecule in DSSC are deeply related to the electron transfer by photoexcitation and redox potential. To date, high performance and good stability of DSSC based on Ru-dyes as a photosensitizer had been widely addressed in the literatures. DSSC with Ru-bipyridyl complexes (N3 and N719), and the black ruthenium dye have achieved power conversion efficiencies up to 11.2% and 10.4%, respectively. However, the Ru-dyes are facing the problem of manufacturing costs and environmental issues. In order to obtain even cheaper photosensitizers for DSSC, metal-free organic photosensitizers are strongly desired. Metal-free organic dyes offer superior molar extinction coefficients, low cost, and a diversity of molecular structures, compared to conventional Ru-dyes. Recently, novel photosensitizers such as coumarin, merocyanine, cyanine, indoline, hemicyanine, triphenylamine, dialkylaniline, bis(dimethylfluorenyl)-aminophenyl, phenothiazine, tetrahydroquinoline, and carbazole based dyes have achieved solar-to-electrical power conversion efficiencies up to 5-9%. On the other hand, organic dye molecules have large ${\pi}$-conjugated planner structures which would bring out strong molecular stacking in their solid-state and poor solubility in their media. It was well known that the molecular stacking of organic dyes could reduce the electron transfer pathway in opto-electronic devices, significantly. In this paper, we have studied on synthesis and characterization of dendritic organic dyes with different number of electron acceptor/anchoring moieties in the end of dendrimer. The photovoltaic performances and the incident photon-to-current (IPCE) of these dyes were measured to evaluate the effects of the dendritic strucuture on the open-circuit voltage and the short-circuit current.

• The Journal of Internal Korean Medicine
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• v.37 no.1
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• pp.65-76
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• 2016

Objectives: The purpose of this study was to identify the inhibitory effects of Hwangheuk-san (HHS), a Korean multi-herb formula comprising four medicinal herbs, on cell migration and invasion, two critical cellular processes that are often deregulated during metastasis, using the human bladder cancer 5637 cell line.Methods: Cell viability, motility, and invasion were assessed by 3-(4,5-dimethyl-2 thiazolyl)-2,5-diphnyl-2H-tetrazolium bromide (MTT), wound healing migration, and Transwell assays, respectively. Gene expression was detected by Western blot analysis. In addition, the activities of matrix metalloproteinases (MMPs) and the values for transepithelial electrical resistance (TER) were analyzed using a Gelatinase Activity Assay Kit and an Epithelial Tissue Voltohmmeter, respectively.Results: Our data indicated that within the concentration range that was not cytotoxic, HHS effectively inhibited the cell motility and invasiveness of 5637 cells. HHS markedly decreased the expression and activity of MMP-2 and MMP-9, which was associated with unregulation of tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2. Further investigation revealed that phosphorylation of phosphatidylinositol 3-kinase (PI3K) and AKT was decreased in HHS-treated 5637 cells, and a PI3K/AKT inhibitor synergistically reduced the inhibition of migration and invasion and also inactivated MMP-2 and MMP-9. Moreover, HHS increased the tightening of tight junctions (TJs), which was demonstrated by an increase in the TER, and reduced the expression the levels of claudin family members (claudin-3 and -4), which are major components involved in the tightening of TJs.Conclusions: The present findings demonstrated that HHS attenuated the migration and invasion of bladder cancer 5637 cells by modulating the activity of the PI3K/Akt signaling pathway and also through TJ tightening.