• Title/Summary/Keyword: Ligand Effects

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Cathodic Stripping Voltammetric Study of Tin(Ⅱ)-Cupferron Complex (Tin(Ⅱ)-Cupferron 착물에 대한 음극벗김전압전류법적 연구)

  • Sohn, Se Chul;Seo, Moo Yul;Jee, kwang Yong;Choi, In kyu
    • Journal of the Korean Chemical Society
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    • v.39 no.1
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    • pp.23-28
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    • 1995
  • Differential-pulse cathodic stripping voltammetry was applied to the Sn(II)-cupferron complex in 0.1 M acetate buffer solution (pH 4.20). Effects of solution pH, ligand concentration, accumulation potential, and accumulation time on the reduction peak current for the adsorptive complex of Sn(II)-cupferron were investigated. Interferences by other metal cations that affected on reduction peak current were also discussed. The detection limit was 3.1${\times}$10-9 M (0.37 ppb) of Sn(II) with 60 seconds accumulation time. The relative standard deviation (n=8) for 5${\times}$10-8 M Sn(II) was 3.0%.

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Administration of Agonistic Anti-4-1BB Monoclonal Antibody Inhibits Melanoma Metastasis Via IFN-${\gamma}$ Production

  • Ju, Seong-A;Lee, Sang-Chul;Seok, Moon-Hong;Kim, Byung-Sam
    • Animal cells and systems
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    • v.8 no.2
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    • pp.117-123
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    • 2004
  • The purpose of this study was to analyze inhibitory effects of anti-4-1BB monoclonal antibody on melanoma metastasis The 4-1BB (CD137) T cell molecule is a member of the TNF receptor family and its activation by either 4-1BB ligand or antibody induces T cell activation and growth. In the present study, administration of anti-4-1BB mAb induced inhibition of melanoma metastasis. Agonistic anti-4-1BB mAb induced not only CD$8^+$4-1BBT cells but also CD$8^+$IFN-${\gamma}$$^{+}$ T cell population. In the presence of anti-CD3 antibody, lymphocytes produced high levels of IFN-${\gamma}$ and low levels of IL-4 in anti-4-1BB mAb treated group. Exposure of melanoma cells to IFN-${\gamma}$ induced expression of MHC-I molecules. Thus, the increase in number of CD$8^+$T cells and enhanced MHC-I expression on B16F10 cells by augmented IFN-${\gamma}$ production in response to anti-4-1BB mAb may result in suppression of tumor growth and metastasis.s.

Effect of Sochungryong-tang Extract on Osteoclast Differentiation and Bone-pit Formation (소청룡탕이 파골세포 분화억제와 골흡수에 미치는 영향)

  • Ahn, Min-Youn;Lim, Hyung-Ho
    • The Journal of Korean Medicine
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    • v.38 no.3
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    • pp.59-72
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    • 2017
  • Objectives: This study was performed to evaluate effects of Sochungryong-tang Extract(SRE) on osteoclast differentiation and bone resorptionin order to find out the possibility for clinical use in preventing and treating osteoporosis. Methods: To evaluate the effect of SRE on osteoclast differentiation, we induced RAW 264. 7 cells to be differentiated to osteoclasts by RANKL (receptor activator of nuclear $factor-{\kappa}B$ ligand). We measured effect on TRAP (Tartrate-resistant acid phosphatase), NFATc, cathepsin K, MMP-9, inflammation related factors, histogenesis factors and bone resorption. Results: SRE decreased osteoclast differentiation, and also decreased expression of bone resorbing factors such as MMP-9, cathepsin K, TRAP, NFATc1, MITF, c-Fos, osteoclast stimulatory transmembrane protein, calcitonin receptor in RANKL-induced osteoclast. SRE also decreased Cyclooxygenase-2, indusible nitric oxide synthase, $TNF-{\alpha}$, which are thought to be related with the inflammatory bone destruction. Conclusion: SRE inhibits osteoclast differentiation and bone resorption. The results indicate that the BHT extract can potentially be applied for preventing and treating osteoporosis.

Inhibitory Effect of Snake Venom Toxin on Colorectal Cancer HCT116 Cells Growth through Induction of Intrinsic or Extrinsic Apoptosis

  • Kim, Kyung Tae;Song, Ho Sueb
    • Journal of Acupuncture Research
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    • v.30 no.1
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    • pp.43-55
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    • 2013
  • I investigated whether snake venom toxin(SVT) from Vipera lebetina turanica enhances the apoptosis ability of tumor necrosis factor(TNF)-related apoptosis-inducing ligand(TRAIL) in cancer cells. TRAIL inhibited HCT116 cell growth in a dose-dependent manner. Consistent with cell growth inhibition, the expression of TRAIL receptors; DR4 and DR5 was significantly increased as well as apoptosis related proteins such as cleaved caspase-3, 8, 9 and Bax. However, the expression of survival proteins(eg, cFLIP, survivin, XIAP and Bcl2) was suppressed by the combination treatment of SVT and TRAIL. Pretreatment with the reactive oxygen species(ROS) scavenger N-acetylcysteine reduced the SVT and TRAIL-induced upregulation of DR4 and DR5 expression and expression of the apoptosis related protein such as caspase-3 and-9 as well as cell growth inhibitory effects. The collective results suggest that SVT facilitates TRAIL-induced apoptosis in human colorectal cancer HCT116 cells through up-regulation of the TRAIL receptors; DR4 and DR5 via ROS pathway signals.

Isolation and Characterization of $\beta$-Galactoside Specific Lectin from Korean Mistletoe (Viscum album var. coloratum with Lactose-BSA-Sepharose 4B and Changes of Lectin Conformation

  • Park, Won-Bong;Ju, Yeun-Jin;Han, Seon-Kyu
    • Archives of Pharmacal Research
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    • v.21 no.4
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    • pp.429-435
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    • 1998
  • Lectins and its A- and B-chains from Korean mistletoe (Viscum album var. coloratum) were isolated by affinity chromatography on the Sepharose 4B modified by lactose-BSA conjugate synthesized by reductive amination of ligand (lactose) to .epsilon.-amino groups of lysine residues of spacer (BSA) after reduction by $NaCNBH_3$. The lactose-BSA conjugate was coupled to Sepharose 4B activated by cyanogen bromide. The molecular weight determined by SDS-PAGE were a 31 kD of A-chain and a 35kD of B-chain. Amino acid analysis and N-terminal sequencing were performed. The effects of pH, temperature and guanidine chloride on the conformation of the lectin were investigated by measuring its intrinsic fluorescence and compared with its hemagglutinating activities. Blue shift was detected on the acidic pH and there was a close relationship between activities and conformation of the lectin. Under denaturing conditions, the tryptophan emission profile of lectin showed typical denaturaiional red shift which also correspond to the conformations and activity of lectin.

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Inhibitory Effects of Wogonin Mixed with Hydrogel on Osteoclast Differentiation (우고닌-하이드로젤 지지체의 파골세포 분화 억제 효과)

  • Yang, Na-Rae;Lee, Jin-Moo;Lee, Chang-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub
    • The Journal of Korean Obstetrics and Gynecology
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    • v.24 no.4
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    • pp.1-9
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    • 2011
  • Purpose: Wogonin is an active component isolated from scutellariae radix. This study was conducted to evaluate the inhibitory effect of wogonin mixed with hydrogel on osteoclast differentiation. Methods: It was performed to estimate cytotoxicity of Wogonin alginate hydrogel disk(WHD) in BMMs stimulated with RANKL, M-CSF. ROS synthesis and actin ring formation were analysed to observe the effect of WHD. Results: WHD has no cytotoxicity at the concentration of 0.1 ${\mu}g/ml$ or lower. 0.1 ${\mu}g/ml$, 1 ${\mu}g/ml$ WHD restrained the synthesis of ROS and 0.1 ${\mu}g/ml$, 1 ${\mu}g/ml$ WHD restrained the formation of actin ring. Conclusions: WHD has the inhibitory effect of osteoclast differentiation and bone resorption. Further studies are needed to treat osteoporosis by herbal medicine.

Improvement of the Biosensor for Detection of Endocrine Disruptors by Combination of Human Estrogen Receptorα and Co-Activator (Human Estrogen Receptor α와 Co-activator로 구성된 바이오센서를 이용한 내분비계장애물질의 검출)

  • Lee, Haeng-Seog
    • Journal of Korean Society of Water and Wastewater
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    • v.20 no.6
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    • pp.893-904
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    • 2006
  • To improve sensitivity of biosensor as yeast two-hybrid detection system for estrogenic activity of suspected chemicals, we tested effects of several combinations of the bait and fish components in the two-hybrid system on Saccharomyces cerevisiae inducted a chromosome-integrated lacZ reporter gene that was under the control of CYC1 promoter and the upstream Gal4p-binding element $UAS_{GAL}$. The bait components that were fused with the Gal4p DNA binding domain are full-length human estrogen receptor ${\alpha}$ and its ligand-binding domain. The fish components that were fused with the Gal4p transcriptional activation domain were nuclear receptor-binding domains of co-activators SRC1 and TIF2. We found that the combination of the full-length human estrogen receptor ${\alpha}$ with the nuclear receptor-binding domain of co-activator SRC1 was most effective for the estrogen-dependent induction of reporter activity among the two-hybrid systems so far reported. The relative strength of transcriptional activation by representative natural and xenobiotic chemicals was well correlated with their estrogenic potency that had been reported with other assay systems.

Osteoclast Activity and Osteoporosis

  • Kim, Hong-Hee
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2001.04a
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    • pp.103-112
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    • 2001
  • Bone homeostasis is maintained by a balance between activities of osteoblasts(bone forming cells) and osteoclasts (bone resorbing cells). The activities of these cells are closely regulated by multiple factors including hormones and cytokines. The cessation of estrogen at menopause disrupts the balanced regulation and is the main cause of osteoporosis in postmenopausal women. Recent molecular biological studies led to a discovery of tumor necrosis factor(TNF) and TNF receptor families genes that play critical roles in the regulation of osteoclast formation and function. RANKL (receptor activator of nuclear factor kappa B ligand; also called ODF, TRANCE, and OPGL) expressed on cells supporting osteoclast is essential for osteoclast differentiation, activation, and survival. RANK, the counter-receptor for RANKL, is expressed on progenitor and mature osteoclasts. The interaction between RANKL and RANK is requlated by a soluble decoy receptor OPG (osteoprotegerin). Gene knock out studies of these molecules showed profound effects on bone. These results prompted development of new strategies for treatment of bone diseases. Inhibition of osteoclast activity by blocking the RANKL-RANK interaction using OPG is being attempted. Research on the signaling pathways of RANK is also actively carried out. Screening natural products that inhibit the RANKL-RANK interaction or the activity of obteoclasts would be another effective means to a new drug target for bone resorbing diseases.

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Anti-inflammatory Activity of Sambucus Plant Bioactive Compounds against TNF-α and TRAIL as Solution to Overcome Inflammation Associated Diseases: The Insight from Bioinformatics Study

  • Putra, Wira Eka;Salma, Wa Ode;Rifa'i, Muhaimin
    • Natural Product Sciences
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    • v.25 no.3
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    • pp.215-221
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    • 2019
  • Inflammation is the crucial biological process of immune system which acts as body's defense and protective response against the injuries or infection. However, the systemic inflammation devotes the adverse effects such as multiple inflammation associated diseases. One of the best ways to treat this entity is by blocking the tumor necrosis factor alpha ($TNF-{\alpha}$) and TNF-related apoptosis-inducing ligand (TRAIL) to avoid the proinflammation cytokines production. Thus, this study aims to evaluate the potency of Sambucus bioactive compounds as anti-inflammation through in silico approach. In order to assess that, molecular docking was performed to evaluate the interaction properties between the $TNF-{\alpha}$ or TRAIL with the ligands. The 2D structure of ligands were retrieved online via PubChem and the 3D protein modeling was done by using SWISS Model. The prediction results of the study showed that caffeic acid (-6.4 kcal/mol) and homovanillic acid (-6.6 kcal/mol) have the greatest binding affinity against the $TNF-{\alpha}$ and TRAIL respectively. This evidence suggests that caffeic acid and homovanillic acid may potent as anti-inflammatory agent against the inflammation associated diseases. Finally, this study needs further examination and evaluation to validate the potency of Sambucus bioactive compounds.

27-Hydroxycholesterol induces macrophage gene expression via LXR-dependent and -independent mechanisms

  • Kim, Bo-Young;Son, Yonghae;Cho, Hyok-rae;Lee, Dongjun;Eo, Seong-Kug;Kim, Koanhoi
    • The Korean Journal of Physiology and Pharmacology
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    • v.25 no.2
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    • pp.111-118
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    • 2021
  • 27-Hydroxycholesterol (27OHChol) exhibits agonistic activity for liver X receptors (LXRs). To determine roles of the LXR agonistic activity in macrophage gene expression, we investigated the effects of LXR inhibition on the 27OHChol-induced genes. Treatment of human THP-1 cells with GSK 2033, a potent cell-active LXR antagonist, results in complete inhibition in the transcription of LXR target genes (such as LXRα and ABCA1) induced by 27OHChol or a synthetic LXR ligand TO 901317. Whereas expression of CCL2 and CCL4 remains unaffected by GSK 2033, TNF-α expression is further induced and 27OHChol-induced CCL3 and CXCL8 genes are suppressed at both the transcriptional and protein translation levels in the presence of GSK 2033. This LXR antagonist downregulates transcript levels and surface expression of CD163 and CD206 and suppresses the transcription of CD14, CD80, and CD86 genes without downregulating their surface levels. GSK 2033 alone had no effect on the basal expression levels of the aforementioned genes. Collectively, these results indicate that LXR inhibition leads to differential regulation of 27-hydroxycholesterol-induced genes in macrophages. We propose that 27OHChol induces gene expression and modulates macrophage functions via LXR-dependent and -independent mechanisms.