• Asian Pacific Journal of Cancer Prevention
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• v.15 no.11
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• pp.4405-4409
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• 2014

Reactive oxygen species (ROS), highly reactive molecules, are produced by living organisms as a result of normal cellular metabolism and environmental factors, and can damage nucleic acids and proteins, thereby altering their functions. The human body has several mechanisms to counteract oxidative stress by producing antioxidants. A shift in the balance between oxidants and antioxidants in favor of oxidants is termed as "oxidative stress". Paradoxically, there is a large body of research demonstrating the general effect of oxidative stress on signaling pathways, less is known about the initial and direct regulation of signaling molecules by ROS, or what we term the "oxidative interface." This review focuses on the molecular mechanisms through which ROS directly interact with critical signaling molecules to initiate signaling in a broad variety of cellular processes, such as proliferation and survival (MAP kinases and PI3 kinase), ROS homeostasis, and antioxidant gene regulation (Ref-1 and Nrf-2). This review also deals with classification as well as mechanisms of formation of free radicals, examining their beneficial and deleterious effects on cellular activities and focusing on the potential role of antioxidants in preventing and repairing damage caused by oxidative stress. A discussion of the role of phytochemical antioxidants in oxidative stress, disease and the epigenome is included.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.74-74
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• 2020

싱가포르의 물분야는 선도적 글로벌 하이드로허브(Global hydrohub)로, 글로벌 물시장에서 싱가포르의 위상을 견고하게 하면서, 지속적으로 괄목할만한 성장세를 이어가고 있다. 200개 이상의 물관련 기업, 25개 이상의 연구소와 더불어, 싱가포르 물분야는 2018년까지 25억 싱가포르달러의 부가가치 창출과 14,400개의 일자리를 창출하면서, 세계 각국으로부터 투자를 유치하고 있다. 또한, 싱가포르는 2006년 이래 국립연구재단(National Research Fund: NRF)에 6억 7천만 싱가포르 달러만큼 기금을 누적하여 2020년에는 28억 싱가포르달러의 부가가치 창출과 15,000개 일자리 창출이라는 목표를 달성 할 수 있을 것으로 예상된다. 이와 더불어 연구, 혁신 및 기업 (Research, Innovation, and Enterprise: RIE) 2020 계획을 달성하기 위하여, 싱가포르 국가 물기관인 PUB, 경제개발이사회(Economic Development Board: EDB) 및 기업싱가포르(Enterprise Singapore)는 싱가포르의 물분야 강점을 활용하여 다음과 같은 세 가지 분야에 초점을 맞추고 있다. 즉 1)"글로벌 국가가 요구하는 솔루션 개발", 2)"기술의 상업화(commercialization)"와 수출"을 가속화하고 3)"다양한 역량과 재능을 육성"하는 것이다. 본 연구는 싱가포르 PUB의 자국 물기업 지원을 위한 전략사례를 분석함으로써 한국 물분야 SOC공공기관의 인프라 건설 및 운영 노하우를 활용한 물분야 부가가치 창출 및 일자리 확대를 통해 현(現)정부의 경제정책 기조인 물분야에 대한 혁신성장과 일자리 창출 방안 마련에 기여하고자 한다. 또한, 본 연구를 통해 물분야 대표적 성공사례인 싱가포르 물분야 공공기관의 운영정책과 PUB의 경영전략을 분석하여, 국내 물기업의 해외진출 활성화를 위한 지원전략 수립의 기초자료를 제공하고자 한다.

• Journal of Veterinary Science
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• v.24 no.2
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• pp.24.1-24.13
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• 2023

Background: Ergothioneine (EGT) is a natural amino acid derivative in various animal organs and is a bioactive compound recognized as a food and medicine. Objectives: This study examined the effects of EGT supplementation during the in vitro maturation (IVM) period on porcine oocyte maturation and subsequent embryonic development competence after in vitro fertilization (IVF). Methods: Each EGT concentration (0, 10, 50, and 100 μM) was supplemented in the maturation medium during IVM. After IVM, nuclear maturation, intracellular glutathione (GSH), and reactive oxygen species (ROS) levels of oocytes were investigated. In addition, the genes related to cumulus function and antioxidant pathways in oocytes or cumulus cells were investigated. Finally, this study examined whether EGT could affect embryonic development after IVF. Results: After IVM, the EGT supplementation group showed significantly higher intracellular GSH levels and significantly lower intracellular ROS levels than the control group. Moreover, the expression levels of hyaluronan synthase 2 and Connexin 43 were significantly higher in the 10 μM EGT group than in the control group. The expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and NAD(P)H quinone dehydrogenase 1 (NQO1) were significantly higher in the oocytes of the 10 μM EGT group than in the control group. In the assessment of subsequent embryonic development after IVF, the 10 μM EGT treatment group improved the cleavage and blastocyst rate significantly than the control group. Conclusions: Supplementation of EGT improved oocyte maturation and embryonic development by reducing oxidative stress in IVM oocytes.

• Biomolecules & Therapeutics
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• v.32 no.3
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• pp.368-378
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• 2024

Cordycepin, a valuable bioactive component isolated from Cordyceps militaris, has been reported to possess anti-cancer potential and the property to enhance the effects of chemotherapeutic agents in various types of cancers. However, the ability of cordycepin to chemosensitize cholangiocarcinoma (CCA) cells to gemcitabine has not yet been evaluated. The current study was performed to evaluate the above, and the mechanisms associated with it. The study analyzed the effects of cordycepin in combination with gemcitabine on the cancer stem-like properties of the CCA SNU478 cell line, including its anti-apoptotic, migratory, and antioxidant effects. In addition, the combination of cordycepin and gemcitabine was evaluated in the CCA xenograft model. The cordycepin treatment significantly decreased SNU478 cell viability and, in combination with gemcitabine, additively reduced cell viability. The cordycepin and gemcitabine co-treatment significantly increased the Annexin V+ population and downregulated B-cell lymphoma 2 (Bcl-2) expression, suggesting that the decreased cell viability in the cordycepin+gemcitabine group may result from an increase in apoptotic death. In addition, the cordycepin and gemcitabine co-treatment significantly reduced the migratory ability of SNU478 cells in the wound healing and trans-well migration assays. It was observed that the cordycepin and gemcitabine cotreatment reduced the CD44^highCD133^high population in SNU478 cells and the expression level of sex determining region Y-box 2 (Sox-2), indicating the downregulation of the cancer stem-like population. Cordycepin also enhanced oxidative damage mediated by gemcitabine in MitoSOX staining associated with the upregulated Kelch like ECH Associated Protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) expression ratio. In the SNU478 xenograft model, co-administration of cordycepin and gemcitabine additively delayed tumor growth. These results indicate that cordycepin potentiates the chemotherapeutic property of gemcitabine against CCA, which results from the downregulation of its cancer-stem-like properties. Hence, the combination therapy of cordycepin and gemcitabine may be a promising therapeutic strategy in the treatment of CCA.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.203-208
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• 2017

The antioxidant and anti-inflammatory effects of roasted dried radish (RDR) against renal oxidative stress were examined in high-fat diet (HFD)-fed mice. The HFD was prepared by adding lard to chow diet to provide 50% of the calories from fat. Hot water extracts of dried radish (DR) or RDR were administered orally to mice at 237 mg/kg bw/day, whereas distilled water was administered as a vehicle for 12 weeks. Compared to the control group, renal reactive oxygen species, peroxynitrite, and thiobarbituric acid reactive substance level in the DR or RDR group were significantly decreased, whereas the glutathione level was increased (p<0.05). Protein expressions of antioxidant factors such as nuclear factor erythroid 2-related factor-2, heme oxygenase-1, glutathione S-transferase, superoxide dismutase, catalase, and glutathione peroxidase were significantly increased in the DR and RDR groups; however, nuclear factor-kappa B expression was suppressed (p<0.05). These antioxidant and anti-inflammatory effects of RDR were found to be significantly greater than those of DR.

• Journal of Life Science
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• v.19 no.8
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• pp.1159-1163
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• 2009

It has been postulated that endoplasmic (ER) stress is involved in the development of several diseases. However, the detailed molecular mechanisms have not been fully understood. Therefore, we characterized a genetic network of genes induced by ER stress using cDNA microarray and gene set expression coherence analysis (GSECA), and identified gene function as well as several transcription regulators associated with ER stress. We analyzed time-dependent gene expression profiles in thapsigargin-treated Sk-Hep1 using an oligonucleotide expression chip, and then selected functional gene sets with significantly high expression coherence which was processed into functional clusters according to the expression similarities. The functions related to sugar binding, lysosome, ribosomal protein, ER lumen, and ER to golgi transport increased, whereas the functions with mRNA processing, DNA replication, DNA repair, cell cycle, electron transport chain and helicase activity decreased. Furthermore, functional clusters were investigated for the enrichment of regulatory motifs using GSECA, and several transcriptional regulators associated with regulation of ER-induced gene expression were found.

• The Korea Journal of Herbology
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• v.33 no.4
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• pp.59-67
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• 2018

Objectives : Ojeoksan, originally recorded in an ancient Korean medicinal book named "Donguibogam" and has been used for the treatment of circulation disorder of blood which was called blood accumulation (血積) in Korean medicine. Therefore, this study was carried out to investigate the beneficial effect of OJS on vascular inflammation in HUVECs. Methods : We evaluated the effect of OJS on the expression of cell adhesion molecules and protective role in HUVEC stimulated by TNF-${\alpha}$ by using Western blot. Results : Pretreatment with OJS decreased the adhesion of HL-60 cells to TNF-${\alpha}$-induced HUVEC. OJS suppressed TNF-${\alpha}$-induced expression level of cell adhesion molecules such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1(VCAM-1), and endothelial cell selectin (E-selectin). Moreover, OJS significantly decreased TNF-${\alpha}$-induced production of intracellular reactive oxygen species (ROS); and inhibited the phosphorylation of $I{\kappa}B-{\alpha}$ in the cytoplasm compared to the experimental group. Pretreatment with OJS inhibited the trans-location of NF-${\kappa}B$ p65 to the nucleus. OJS also inhibited phosphorylation of MAPKs compared to the experimental group. OJS significantly increased the protein expression of Nrf2 and HO-1. Conclusions : Ojeoksan has a protective effect on vascular inflammation, and might be a potential therapeutic agent for early atherosclerosis.

• BMB Reports
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• v.49 no.10
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• pp.548-553
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• 2016

Mesenchymal stem cells (MSCs) are widely used in cartilage tissue engineering to repair articular cartilage defects. However, hypertrophy of chondrocytes derived from MSCs might hinder the stabilization of hyaline cartilage. Thus, it is very important to find a suitable way to maintain the chondrogenic phenotype of chondrocytes. It has been reported that cordycepin has anti-inflammatory and anti-tumor functions. However, the role of cordycepin in chondrocyte hypertrophy remains unclear. Therefore, the objective of this study was to determine the effect of cordycepin on chondrogenesis and chondrocyte hypertrophy in MSCs and ATDC5 cells. Cordycepin upregulated chondrogenic markers including Sox9 and collagen type II while down-regulated hypertrophic markers including Runx2 and collagen type X. Further exploration showed that cordycepin promoted chondrogenesis through inhibiting Nrf2 while activating BMP signaling. Besides, cordycepin suppressed chondrocyte hypertrophy through PI3K/Bapx1 pathway and Notch signaling. Our results indicated cordycepin had the potential to maintain chondrocyte phenotype and reconstruct engineered cartilage.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.6
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• pp.239-246
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• 2007

Expressions of endoplasmic reticulum stress response (ERSR) genes were examined during the neuronal differentiation of rat fetal cortical precursor cells (rCPC) and rat pheochromocytoma PC12 cells. When rCPC were differentiated into neuronal cells for 7 days, early stem cell marker, nest in, expression was decreased from day 4, and neuronal markers such as neurofilament-L, -M and Tuj1 were increased after day 4. In this condition, expressions of BIP, ATF6, and phosphorylated PERK as well as their down stream signaling molecules such as CHOP, ATF4, XBP1, GADD34, Nrf2 and $p58^{IPK}$ were significantly increased, suggesting the induction of ERSR during neuronal differentiation of rCPC. ERSR was also induced during the differentiation of PC12 cells for 9 days with NGF. Neurofilament-L transcript was time-dependently increased. Both mRNA and protein levels of Tuj1 were increased after the induction, and the significant increase in NeuN was observed at day 9. Similar to the expression patterns of neuronal markers, BIP/GRP78 and CHOP mRNAs were highly increased at day 9, and ATF4 mRNA was also increased from day 7. These results strongly suggest the induction and possible role of ERSR in neuronal differentiation process. Further study to identify targets responsible for neuronal induction will be necessary.

• Journal of Ginseng Research
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• v.44 no.4
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• pp.580-592
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• 2020

Background: Radix et Rhizoma Ginseng (thereafter called ginseng) has been used as a medicinal herb for thousands of years to maintain people's physical vitality and is also a non-organ-specific cancer preventive and therapeutic traditional medicine in several epidemiologic and preclinical studies. Owing to few toxic side effects and strong enhancement on body immunity, ginseng has admirable application potential and value in cancer chemoprevention. The study aims at investigating the chemopreventive effects of ginseng on cutaneous carcinoma and the underlying mechanisms. Methods: The mouse skin cancer model was induced by 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoylphorbol-13-acetate. Ultraperformance liquid chromatography/mass spectrometry was used for identifying various ginsenosides, the main active ingredients of ginseng. Comprehensive approaches (including network pharmacology, bioinformatics, and experimental verification) were used to explore the potential targets of ginseng. Results: Ginseng treatment inhibited cutaneous carcinoma in terms of initiation and promotion. The content of Rb1, Rb2, Rc, and Rd ginsenosides was the highest in both mouse blood and skin tissues. Ginseng and its active components well maintained the redox homeostasis and modulated the immune response in the model. Specifically, ginseng treatment inhibited the initiation of skin cancer by enhancing T-cell-mediated immune response through upregulating HSP27 expression and inhibited the promotion of skin cancer by maintaining cellular redox homeostasis through promoting nuclear translocation of Nrf2. Conclusion: According to the study results, ginseng can be potentially used for cutaneous carcinoma as a chemopreventive agent by enhancing cell-mediated immunity and maintaining redox homeostasis with multiple components, targets, and links.