• 공업화학
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• 제29권1호
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• pp.49-55
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• 2018

본 연구에서는 그라비올라의 주성분인 nicotiflorin을 분리하고 그 아글리콘 성분인 kaempferol을 얻어 세포 보호 효과 및 그 보호 메커니즘을 규명하였다. L-Ascorbic acid 및 (+)-${\alpha}$-tocopherol을 대조군으로 하여, $^1O_2$로 유도된 세포 손상에 대해 nicotiflorin 및 kaempferol의 보호 효과를 측정한 결과 nicotiflorin < (+)-${\alpha}$-tocopherol < kaempferol 순으로 보호 효과가 증가하였다. L-Ascorbic acid는 세포 보호 효과를 보이지 않았다. 이들의 세포 보호 효과 메커니즘을 밝히기 위해 singlet oxygen 소광 속도 상수, 자유라디칼 소거 활성, ROS 소거 활성 및 적혈구 세포 침투율을 측정하였다. 실험 결과, kaempferol과 그 배당체인 nicotiflorin의 세포 보호 효과에 있어서 큰 차이는 세포막에의 침투가 가장 큰 요인으로 확인되었다. 대조군 L-ascorbic acid가 항산화능은 크지만 실험 조건에서 세포막에 침투가 잘 안되어 세포 보호 효과가 나타나지 않은 것으로 확인되었다. Kaempferol과 (+)-${\alpha}$-tocopherol의 비교를 통해 세포 침투뿐만 아니라 라디칼 소거활성 및 ROS 소거 활성도 세포 보호 효과에 기여하는 것으로 나타났다. 결론적으로, 광증감 반응으로 유도된 세포막 파괴에 대한 보호작용은 항산화제들의 세포 침투, 자유라디칼 및 ROS 소거 활성이 큰 영향을 미치는 것으로 확인되었다.

• Molecules and Cells
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• 제37권12호
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• pp.841-850
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• 2014

Polycomb group (PcG) proteins are conserved chromatin regulators involved in the control of key developmental programs in eukaryotes. They collectively provide the transcriptional memory unique to each cell identity by maintaining transcriptional states of developmental genes. PcG proteins form multi-protein complexes, known as Polycomb repressive complex 1 (PRC1) and Polycomb repressive complex 2 (PRC2). PRC1 and PRC2 contribute to the stable gene silencing in part through catalyzing covalent histone modifications. Components of PRC1 and PRC2 are well conserved from plants to animals. PcG-mediated gene silencing has been extensively investigated in efforts to understand molecular mechanisms underlying developmental programs in eukaryotes. Here, we describe our current knowledge on PcG-mediated gene repression which dictates developmental programs by dynamic layers of regulatory activities, with an emphasis given to the model plant Arabidopsis thaliana.

• BMB Reports
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• 제53권4호
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• pp.181-190
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• 2020

Protein phosphatase 4 (PP4), one of serine/threonine phosphatases, is involved in many critical cellular pathways, including DNA damage response (DNA repair, cell cycle regulation, and apoptosis), tumorigenesis, cell migration, immune response, stem cell development, glucose metabolism, and diabetes. PP4 has been steadily studied over the past decade about wide spectrum of physiological activities in cells. Given the many vital functions in cells, PP4 has great potential to develop into the finding of key working mechanisms and effective treatments for related diseases such as cancer and diabetes. In this review, we provide an overview of the cellular and molecular mechanisms by which PP4 impacts and also discuss the functional significance of it in cell health.

• Journal of Ginseng Research
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• 제21권1호
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• pp.19-27
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• 1997

The present study was conducted to assess the effect of total saponins from Korean red ginseng on the biosynthesis of inositol phospholipids in vivo and also effects on the metabolic enzymes, such as phosphatidylinositol-specific phospholipase C(Pl-PLC) and PI-kinases. The administration of 0.1% saponin solution, 0.1 ml 3 times a day intraperitoneally to 5 mice for 30 days has increased a 23% of the body weight when it compared with a control group. The amounts of 32P-phoschorus radioactivity incorporated into the phosphoinositides from the liver and brain tissues have increased a 310% and 260%, respectively, in the saponin treated mice. The activities of PI-PLC from liver and brain were stimulated in the various amounts by the conditions treated with saponins. The PI-kinases from liver and brain were also activated by saponins, but its effect was lower than that of PI-PLC. From these results, it was confirmed that red ginseng saponins have affected positively not only on the biosynthesis of phosphoinositides but also on the PI-PLC and PI-kinases related to the cellular signal transduction.

• Biomolecules & Therapeutics
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• 제19권4호
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• pp.390-397
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• 2011

G protein-coupled receptor kinases (GRKs) and ${\beta}$-arrestins have been known as regulators of G protein-coupled receptors. However, it has been recently reported that GRKs and ${\beta}$-arrestins mediate receptor-mediated cellular responses in a G proteinin-dependent manner. In this scheme, GRKs work as a mediator or a scaffold protein. Among 7 members of the GRK family (GRK1-GRK7), GRK2 is the most extensively studied in vitro and in vivo. GRK2 is involved in cellular migration, insulin signaling, and cardiovascular disease. GRK6 in concert with ${\beta}$-arrestin 2 mediates chemoattractant-stimulated chemotaxis of T and B lymphocytes. GRK5 shuttles between the cytosol and nucleus, and regulates the activities of transcription factors. GRK3 and GRK4 do not seem to have striking effects on cellular responses other than receptor regulation. GRK1 and GRK7 play specific roles in regulation of rhodopsin function. In this review, these newly discovered functions of GRKs are briefly described.

• The Korean Journal of Physiology and Pharmacology
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• 제17권6호
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• pp.531-536
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• 2013

Interstitial cells of Cajal (ICCs) from the urinary bladder regulate detrusor smooth muscle activities. We cultured ICCs from the urinary bladder of mice and performed patch clamp and intracellular $Ca^{2+}$ ($[Ca^{2+}]_i$) imaging to investigate whether cultured ICCs can be a valuable tool for cellular functional studies. The cultured ICCs displayed two types of spontaneous electrical activities which are similar to those recorded in intact bladder tissues. Spontaneous electrical activities of cultured ICCs were nifedipine-sensitive. Carbachol and ATP, both excitatory neurotransmitters in the urinary bladder, depolarized the membrane and increased the frequency of spike potentials. Carbachol increased $[Ca^{2+}]_i$ oscillations and basal $Ca^{2+}$ levels, which were blocked by atropine. These results suggest that cultured ICCs from the urinary bladder retain rhythmic phenotypes similar to the spontaneous electrical activities recorded from the intact urinary bladder. Therefore, we suggest that cultured ICCs from the urinary bladder may be useful for cellular and molecular studies of ICCs.

• 생약학회지
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• 제21권3호
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• pp.223-234
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• 1990

Hepatoprotective activities of 26 traditional Korean herbal prescriptions described in Donghibogam were evaluated in vivo and in vitro screening system. Twenty one prescriptions appeared to be active. Six prescriptions among them showed highly significant hepatoprotective activities; Shihogyegy-Tang(柴胡桂枝湯), Soshiho-Tang(小柴胡湯), Shiho plus Younggolmoryo-Tang(柴胡加龍骨牡蠣湯), Yinjinho-Tang(茵蔯蒿湯), Yinsam-Tang(人蔘湯) and Shashim-Tang(瀉心湯). Shihogyegy-Tang was most active. They reduced the release of transaminases from dissociated hepatocytes by thioacetamide, and serum transaminases and alkaline phosphatase activities of rat with carbontetrachloride-induced hepatitis. They inhibited significantly lipid peroxidation and cellular fatty change of liver by carbontetrachloride.

• Fisheries and Aquatic Sciences
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• 제16권4호
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• pp.229-235
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• 2013

In an effort to develop biopolymer-based antioxidant and antibacterial materials, a chitosan-phloroglucinol conjugate was prepared and cellular antioxidant activity and minimum inhibitory concentration against foodborne pathogens and methicillin-resistant Staphylococcus aureus (MRSA) evaluated. The chitosan-phloroglucinol conjugate showed higher antioxidant activities than the unmodified chitosan (P < 0.05). The chitosan-phloroglucinol conjugate showed 62.29% reactive oxygen species scavenging activity, 56.11% lipid peroxidation inhibition activity, and 2.21-fold increase of glutathione expression in mouse macrophage cells. Additionally, the chitosan-phloroglucinol conjugate exhibited higher antibacterial activities than the unmodified chitosan, and the chitosan-phloroglucinol conjugate showed fourfold higher antibacterial activities against MRSA and clinical isolates and twofold higher activities against foodborne pathogens compared to the unmodified chitosan.

• Environmental Analysis Health and Toxicology
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• 제16권1호
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• pp.9-16
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• 2001

It is known that alcoholics have significantly lower mitochondrial aldehyde dehydrogenase (ALDH)s'activity than do normal subjects or nonalcoholics with liver disease. However, there are only few reports that explain the reasons behind this reduction of ALDHs'activities. In this study, ALDH activity is inhibited by acetaldehyde, a substrate for ALDH However, the addition of glutathione (GSH) protected ALDH activities against the inhibitory effects of acetaldehyde in vitro. Furthermore, when GSH depletion is induced using diethyl maleate (DEM) in rats by 24% in cytosol and 43% in mitochondria, ALDH activities were also depressed by 31% and 63%, respectively compared to non-treated rats without significant reductions in other hepatic enzymes. These results suggest that ALDHs'activities are closely related to the concentration of acetaldehyde and/or cellular GSH contents . Therefore in alcoholic liver disease, increased productions of acetaldehyde and decreased contents of mitochondrial GSH may involved in the depression of ALDHs'activities.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.5-6
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• 2008

With the continued evolution of third-generation cellular systems and the introduction of 3GP P LTE, there is considerable progress for the new mobile wireless markets. Recently, 3GPP LTE standards are accelerated by mobile operators supporting LTE deployment and special working groups such as LSTI are working for LTE IOT and trials. In this paper, we introduce the current status of LTE activities in the mobile communications industry.