• BMB Reports
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• v.55 no.12
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• pp.627-632
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• 2022

Dickkopf-1 (DKK1) is a secreted protein that acts as an antagonist of the canonical WNT/β-catenin pathway, which regulates osteoblast differentiation. However, the role of DKK1 on osteoblast differentiation has not yet been fully clarified. Here, we investigate the functional role of DKK1 on osteoblast differentiation. Primary osteoprogenitor cells were isolated from human spinal bone tissues. To examine the role of DKK1 in osteoblast differentiation, we manipulated the expression of DKK1, and the cells were differentiated into mature osteoblasts. DKK1 overexpression in osteoprogenitor cells promoted matrix mineralization of osteoblast differentiation but did not promote matrix maturation. DKK1 increased Ca⁺ influx and activation of the Ca⁺/calmodulin-dependent protein kinase II Alpha (CAMK2A)-cAMP response element-binding protein 1 (CREB1) and increased translocation of p-CREB1 into the nucleus. In contrast, stable DKK1 knockdown in human osteosarcoma cell line SaOS2 exhibited reduced nuclear translocation of p-CREB1 and matrix mineralization. Overall, we suggest that manipulating DKK1 regulates the matrix mineralization of osteoblasts by Ca⁺-CAMK2A-CREB1, and DKK1 is a crucial gene for bone mineralization of osteoblasts.

• BMB Reports
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• v.56 no.7
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• pp.398-403
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• 2023

Natural killer (NK) cells are an essential part of the innate immune system that helps control infections and tumors. Recent studies have shown that Vorinostat, a histone deacetylase (HDAC) inhibitor, can cause significant changes in gene expression and signaling pathways in NK cells. Since gene expression in eukaryotic cells is closely linked to the complex three-dimensional (3D) chromatin architecture, an integrative analysis of the transcriptome, histone profiling, chromatin accessibility, and 3D genome organization is needed to gain a more comprehensive understanding of how Vorinostat impacts transcription regulation of NK cells from a chromatin-based perspective. The results demonstrate that Vorinostat treatment reprograms the enhancer landscapes of the human NK-92 NK cell line while overall 3D genome organization remains largely stable. Moreover, we identified that the Vorinostat-induced RUNX3 acetylation is linked to the increased enhancer activity, leading to elevated expression of immune response-related genes via long-range enhancer-promoter chromatin interactions. In summary, these findings have important implications in the development of new therapies for cancer and immune-related diseases by shedding light on the mechanisms underlying Vorinostat's impact on transcriptional regulation in NK cells within the context of 3D enhancer network.

• Journal of Microbiology and Biotechnology
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• v.29 no.11
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• pp.1817-1829
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• 2019

Porcine deltacoronavirus (PDCoV) is an emerging swine enteric coronavirus that causes diarrhea in neonatal piglets. Like other coronaviruses, PDCoV encodes at least three accessory or species-specific proteins; however, the biological roles of these proteins in PDCoV replication remain undetermined. As a first step toward understanding the biology of the PDCoV accessory proteins, we established a stable porcine cell line constitutively expressing the PDCoV NS7 protein in order to investigate the functional characteristics of NS7 for viral replication. Confocal microscopy and subcellular fractionation revealed that the NS7 protein was extensively distributed in the mitochondria. Proteomic analysis was then conducted to assess the expression dynamics of the host proteins in the PDCoV NS7-expressing cells. High-resolution two-dimensional gel electrophoresis initially identified 48 protein spots which were differentially expressed in the presence of NS7. Seven of these spots, including two up-regulated and five down-regulated protein spots, showed statistically significant alterations, and were selected for subsequent protein identification. The affected cellular proteins identified in this study were classified into functional groups involved in various cellular processes such as cytoskeleton networks and cell communication, metabolism, and protein biosynthesis. A substantial down-regulation of α-actinin-4 was confirmed in NS7-expressing and PDCoV-infected cells. These proteomic data will provide insights into the understanding of specific cellular responses to the accessory protein during PDCoV infection.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.183-187
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• 2008

Vascular endothelial growth factors (VEGFs) are a family of proteins that mediate angiogenesis. $VEGF_{165}$ is a VEGF-A isoform and has been extensively studied owing to its potential use in therapeutic angiogenesis. This study established Chinese hamster ovary (CHO) cells overexpressing recombinant human $VEGF_{165}$ $(rhVEGF_{165})$ protein. The production rate of the established CHO cells was over 80mg/l of $rhVEGF_{165}$ protein from a 7-day batch culture process using a 7.5-l bioreactor with a 5-l working volume and serum-free medium. The $rhVEGF_{165}$ protein was purified to homogeneity from the culture supernatant using a two-step chromatographic procedure that resulted in a 48% recovery rate. The purified $rhVEGF_{165}$ protein was a glycosylated homodimeric protein with a higher molecular weight (MW) than the protein expressed from insect cells, suggesting that the glycosylation of the $rhVEGF_{165}$ protein in CHO cells differed from that in insect cells. The purified $rhVEGF_{165}$ protein in this study was functionally active with a half-maximal effective concentration of 3.8ng/ml and specific activity of $2.5{\times}10^5U/mg$.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.348-354
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• 2003

This study was conducted to confirm the availability of lactic acid bacteria as probiotics haying inhibitory effects to cancer cell line. Five lactic acid bacteria showing anti-cancer activity were compared by acid tolerance, bile tolerance, antibiotics resistance, milk fermentation, stability, and cell adherence activity to colon epithelial cell. The results obtained are as follows : In acid tolerance, all strains did not have a resistance below pH 3.0 and 3.5 except Lactobacillus plantarum KCTC3099. In antibiotics resistance, Lactococcus lactis and L. plantarum KCTC3099 were resistant to cotrimoxazol (128 mg/1), and Bifidobacterium adolescentis Maeil-K8 and B. infantis Maeil-K9 were resistant to doxycylin and gentamycin (4 mg/1). In case of cell adherence ability to Caco-2 cell, B. infantis Maeil-K9 was found to be superior to others as 3.1%, while the others were less than 0.5%. When the strains were cultured to milk base, viable counts of the strains tested increased more 1 log cycle than inoculation, but acid production was very low except L. plantarum KCTC3099. Also, L. plantarum KCTC3099, B. adolescentis Maeil-K8, and B. infantis Maeil-K9 were stable in fermented milk base during storage. In conclusion, L. plantarum KCTC3099 and B. infantis Maeil-K9 were confirmed to be superior for the availability as probiotics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.360-369
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• 2008

The solar cells should be operated at the maximum power point because its output characteristics were greatly fluctuated on the variation of insolation, temperature and load. It is necessary to install an inverter among electric power converts by means of the output power of solar cell is DC. The inverter is operated supply a sinusoidal current and voltage to the load and the interactive utility line. In this paper, the proposes a photovoltaic system is designed with a step up chopper and single phase PWM voltage source inverter. Synchronous signal and control signal was processed by one-chip microprocessor for stable modulation. The step up chopper is operated in continuous mode by adjusting the duty ratio so that the photovoltaic system tracks the maximum power point of solar cell without any influence on the variation of insolation and temperature for solar cell has typical dropping character. The single phase PWM voltage source inverter is consists of complex type of electric power converter to compensate for the defect, that is, solar cell cannot be develop continuously by connecting with the source of electric power for ordinary using. It can be cause the efect of saving electric power, from 10 to 20%. The single phase PWM voltage source inverter operates in situation, that its output voltage is in same phase with the utility voltage. The inverter are supplies an ac power with high factor and low level of harmonics to the load and the utility power system.

• Molecules and Cells
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• v.41 no.5
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• pp.413-422
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• 2018

Soybean transgenic plants with ectopically expressed AtABF3 were produced by Agrobacterium-mediated transformation and investigated the effects of AtABF3 expression on drought and salt tolerance. Stable Agrobacterium-mediated soybean transformation was carried based on the half-seed method (Paz et al. 2006). The integration of the transgene was confirmed from the genomic DNA of transformed soybean plants using PCR and the copy number of transgene was determined by Southern blotting using leaf samples from $T_2$ seedlings. In addition to genomic integration, the expression of the transgenes was analyzed by RT-PCR and most of the transgenic lines expressed the transgenes introduced. The chosen two transgenic lines (line #2 and #9) for further experiment showed the substantial drought stress tolerance by surviving even at the end of the 20-day of drought treatment. And the positive relationship between the levels of AtABF3 gene expression and drought-tolerance was confirmed by qRT-PCR and drought tolerance test. The stronger drought tolerance of transgenic lines seemed to be resulted from physiological changes. Transgenic lines #2 and #9 showed ion leakage at a significantly lower level (P < 0.01) than ${\underline{n}}on-{\underline{t}}ransgenic$ (NT) control. In addition, the chlorophyll contents of the leaves of transgenic lines were significantly higher (P < 0.01). The results indicated that their enhanced drought tolerance was due to the prevention of cell membrane damage and maintenance of chlorophyll content. Water loss by transpiration also slowly proceeded in transgenic plants. In microscopic observation, higher stomata closure was confirmed in transgenic lines. Especially, line #9 had 56% of completely closed stomata whereas only 16% were completely open. In subsequent salt tolerance test, the apparently enhanced salt tolerance of transgenic lines was measured in ion leakage rate and chlorophyll contents. Finally, the agronomic characteristics of ectopically expressed AtABF3 transgenic plants ($T_2$) compared to NT plants under regular watering (every 4 days) or low rate of watering condition (every 10 days) was investigated. When watered regularly, the plant height of drought-tolerant line (#9) was shorter than NT plants. However, under the drought condition, total seed weight of line #9 was significantly higher than in NT plants (P < 0.01). Moreover, the pods of NT plants showed severe withering, and most of the pods failed to set normal seeds. All the evidences in the study clearly suggested that overexpression of the AtABF3 gene conferred drought and salt tolerance in major crop soybean, especially under the growth condition of low watering.

• BMB Reports
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• v.40 no.4
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• pp.467-474
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• 2007

Autosomal recessive polycystic kidney disease (ARPKD) is one of the important genetic disorders in pediatric practice. Mutation of the polycystic kidney and hepatic disease gene 1 (PKHD1) was identified as the cause of ARPKD. The gene encodes a 67-exon transcript for a large protein of 4074 amino acids termed fibrocystin, but its function remains unknown. The neoplastic-like in cystic epithelial proliferation and the epidermal growth factor/epidermal growth factor receptor (EGF/EGFR) axis overactivity are known as the most important characteristics of ARPKD. Since the misregulation of $Ca^{2+}$ signaling may lead to aberrant structure and function of the collecting ducts in kidney of rat with ARPKD, present study aimed to investigate the further mechanisms of abnormal proliferation of cystic cells by inhibition of PKHD1 expression. For this, a stable PKHD1-silenced HEK-293T cell line was established. Then cell proliferation rates, intracellular $Ca^{2+}$ concentration and extracellular signal-regulated kinase 1/2 (ERK1/2) activity were assessed after treatment with EGF, a calcium channel blocker and agonist, verapamil and Bay K8644. It was found that PKHD1-silenced HEK-293T cell lines were hyperproliferative to EGF stimulation. Also PKHD1-silencing lowered the intracellular $Ca^{2+}$ and caused EGF-induced ERK1/2 overactivation in the cells. An increase of intracellular $Ca^{2+}$ in PKHD1-silenced cells repressed the EGF-dependent ERK1/2 activation and the hyperproliferative response to EGF stimulation. Thus, inhibition of PKHD1 can cause EGF-induced excessive proliferation through decreasing intracellular $Ca^{2+}$ resulting in EGF-induced ERK1/2 activation. Our results suggest that the loss of fibrocystin may lead to abnormal proliferation in kidney epithelial cells and cyst formation in ARPKD by modulation of intracellular $Ca^{2+}$.

• Journal of Pharmacopuncture
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• v.15 no.2
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• pp.31-35
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• 2012

Background and Objectives: Non-small-cell lung cancer (NSCLC) represents approximately 80% of all lung cancers. Unfortunately, at their time of diagnosis, most patients have advanced to unresectable disease with a very poor prognosis. The oriental herbal medicine HangAm-Plus (HAP) has been developed for antitumor purposes, and several previous studies have reported its therapeutic effects. In this study, the efficacy of HAP was evaluated as a third-line treatment for advanced-stage IIIb/IV NSCLC. Methods: The study involved six patients treated at the East- West Cancer Center (EWCC) from April 2010 to October 2011. Inoperable advanced-stage IIIb/IV NSCLC patients received 3,000 or 6,000 mg of HAP on a daily basis over a 12-week period. Computed tomography (CT) scans were obtained from the patients at the time of the initial administration and after 12 weeks of treatment. We observed and analyzed the patients overall survival (OS) and progression-free survival (PFS). Results: Of the six patients, three expired during the study, and the three remaining patients were alive as of October 31, 2011. The OS ranged from 234 to 512 days, with a median survival of 397 days and a one-year survival rate of 66.7%. In the 12-week-interval chest CT assessment, three patients showed stable disease (SD), and the other three showed progressive disease (PD). The PFS of patients ranged from 88 to 512 days, the median PFS being 96 days. Longer OS and PFS were correlated with SD. Although not directly comparable, the OS and the PFS of this study were greater than those of the docetaxel or the best supportive care group in other studies. Conclusion: HAP may prolong the OS and the PFS of inoperable stage IIIb/IV NSCLC patients without significant adverse effects. In the future, more controlled clinical trials with larger samples from multi-centers should be conducted to evaluate the efficacy and the safety of HAP.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1427-1433
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• 2006

The antioxidant activity, nitrite scavenging effect, and angiotensine I-converting enzyme inhibiting activity of solvent extracts of soybean isoflavone were investigated. Also anticarcinogenic activities of them were examined by MTT assay using human cancer cell line. Isoflavone aglycones showed relatively high antioxidant activity in order of glycitein, genistein, and daidzein. Methanol extract of soybean actively scavenged free radicals and was shown excellent nitrite scavenging effect. Glycitein and methanol extract of soybean inhibited the growth of human cancer cell such as stomach carcinoma (SNU-1) and colon carcinoma (SNU-C4) effectively. Genistein, daidzein and methanol extracts of soybean inhibited the growth of cancer cell such as stomach carcinoma (SNU-1), but had weak activities to colon carcinoma (SNU-C4). To applicate the soybean isoflavone as an enhancer for food quality and processibility, the stabilities on heat and pH of isolated isoflavone, isoflavone in soybean flour and isoflavone concentrate of soybean were investigated. Stability of isoflavone concentrate of soybean was decreased in pH extreme (below 3, above 8) during sterilization, but isoflavone in soybean flour showed higher stability in all pH range. All kinds of isoflavone tested in this study were very stable during the heat treatment.