Publications by authors named "Sung-Woo Ryoo"

The incidence of cardiovascular disease is predicted to increase as the population ages. There is accumulating evidence that arginase upregulation is associated with impaired endothelial function. Here, we demonstrate that arginase II (ArgII) is upregulated in aortic vessels of aged mice and contributes to decreased nitric oxide (NO) generation and increased reactive oxygen species (ROS) production via endothelial nitric oxide synthase (eNOS) uncoupling.

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A new alkaloid, methyl 2'-(7,8-dihydrosanguinarine-8-yl)acetate (1), together with six known alkaloids, stylopine (2), protopine (3), norchelidonine (4), chelidonine (5), berberine (6), and 8-hydroxydihydrosanguinarine (7), were isolated from Chelidonium majus. Their chemical structures were primarily established using 1D and 2D NMR techniques and mass spectrometry. The anti-inflammatory activity of the isolates was examined for their inhibitory effects on LPS-induced NO production in macrophage RAW264.

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Three new phenolics: ((7S)-8'-(benzo[3',4']dioxol-1'-yl)-7-hydroxypropyl)benzene-2,4-diol (1), ((7S)-8'-(4'-hydroxy-3'-methoxyphenyl)-7-hydroxypropyl)benzene-2,4-diol (2) and ((8R,8'S)-7-(4-hydroxy-3-methoxyphenyl)-8'-methylbutan-8-yl)-3'-methoxybenzene-4',5'-diol (3), along with four known compounds (4-7) were isolated from the seeds of Myristica fragrans. Their chemical structures were established mainly by 1D and 2D NMR techniques and mass spectrometry. Their anti-inflammatory activity was evaluated against LPS-induced NO production in macrophage RAW264.

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In the course of screening plants used in folk medicine as memory enhancers, a 70% ethanolic extract of Stephania rotunda roots showed significant AChE inhibitory activity. Repeated column chromatography led to the isolation of a new protoberberine alkaloid, which we named stepharotudine (1), and seven known compounds (2-8). The chemical structures of the isolated compounds were elucidated based on extensive 1D and 2D NMR spectroscopic data.

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Three new homoisoflavonoids (1-3) were isolated from the roots of Ophiopogon japonicus (Liliaceae). The structures of new metabolites were determined on the basis of spectroscopic analyses including 2D NMR. The anti-inflammatory activities of new compounds (1-3) were investigated by their effects on the release of the inflammatory chemokine eotaxin, stimulated by IL-4 and the combination of IL-4 and TNF-alpha in BEAS-2B cells, which mimics the in vivo conditions in bronchial allergic asthma.

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Low-density lipoprotein (LDL) induces cell proliferation in human aortic smooth muscle cells (hAoSMCs), which may be involved in atherogenesis and intimal hyperplasia. Recent studies have demonstrated that Cl- channels are related to vessel cell proliferation induced by a variety of stimuli. In this study, we investigated a potential role of Cl-channels in the signaling pathway of LDL effects on hAoSMC proliferation with a focus on the activation of Erk1/2-PI3K/Akt and the subsequent upregulation of Egr-1.

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Objective: Expression of adhesion molecules on endothelial cells and subsequent monocyte adhesion are initial events in the development of atherosclerosis. The purpose of this study was to investigate the role of apurinic/apyrmidinic endonuclease1/redox factor-1 (APE1/ref-1) in the interaction of monocytes with vascular endothelial cells.

Methods: Human umbilical vein endothelial cells (HUVECs) were transfected with an adenovirus encoding human APE1/ref-1.

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Background And Objectives: Endothelial and monocytic cells appear to play a key role in the initiation and progression of atherosclerosis and restenosis via the upregulation of inflammatory cytokines and the formation of oxidized low-density lipoprotein (ox-LDL). However, the role of smooth muscle cells (SMCs) has been underestimated and is not well understood. It was investigated for the first time that native LDL stimulates human SMCs to secrete IL-8.

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We report here the first functional over-expression of the Stm1 protein, a G-protein-coupled receptor with seven-trans-membrane spanning regions, in a homologous expression system without internal modification of the open reading frame of Stm1. The entire coding sequence, except for the termination codon followed by a C-terminal His6 tag, has been cloned into the pREP1 vector. The functionally active Stm1-His6 was over-expressed in Schizosaccharomyces pombe under the control of the nmt1 (no message in thiamine) promoter.

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Aim: To investigate the effects of Korea red ginseng (KRG) on the cerebral perfusion rate in the rats and the generation of superoxide anion in the endothelial cells.

Methods: The cerebral perfusion rate was measured using laser-doppler flowmetry before and after the administration of crude saponin (CS) and saponin-free fraction (SFF) of KRG in the anesthetized rats. The superoxide generation was measured by the method based on lucigenin-enhanced chemiluminescence in the cultured endothelial cells.

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