• 제목/요약/키워드: Ligand effect

검색결과 423건 처리시간 0.026초

The Chemokine SDF-1α Suppresses Fibronectin-mediated In Vitro Lymphocytes Adhesion

  • Ji, LiLi;Sheng, YuChen;Wang, ZhengTao
    • Molecules and Cells
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    • 제22권3호
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    • pp.308-313
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    • 2006
  • Stromal cell-derived factor (SDF-1) is a CXC chemokine that selectively activates the CXCR4 chemokine receptor. Fibronectin is an intracellular matrix component that binds integrin and mediates cell-matrix adhesion. Activation of the integrin receptor can occur in two ways: by ligand binding (outside-in signaling), and in response to intracellular events (inside-out signaling). In the current study we showed that SDF-$1{\alpha}$ inhibited adhesion of T lymphocyte Jurkat cells resulting from binding high concentrations of fibronectin as well as that of THP-1 monocytes. The effect of SDF-$1{\alpha}$ on fibronectin-mediated adhesion was partly reversed by the CXCR4 receptor antagonist T140. Our results suggest that an SDF-1/CXCR4 signal pathway modulates fibronectin-mediated lymphocytes adhesion.

유기전기발광소자에 사용될 수 있는 백금 착물에 대해 보조리간드 phenyl 기가 발광스펙트럼에 미치는 영향 (Effect of Ancillary Ligand, Phenyl group, on the Emission Spectrum of Pt(II) Complex Useful for Organic Light-Emitting Device)

  • 이승희;이호준
    • 한국응용과학기술학회지
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    • 제25권2호
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    • pp.265-268
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    • 2008
  • Among the efforts to increase the efficiency of organic light-emitting device (OLED), there is a way: doping phosphorescent materials. As a phosphorescent material, complexes of heavy transition metal, platinum, were synthesized. $Cl^-$ ion and phenyl group were used as ancillary ligands with 2-(2-pyridyl)benzimidazole (pbi) as a chromophore. The complexes were analysed by FAB-mass spectrometer and absorption and emission spectra were obtained. A phenyl group was able to shift the emission band of the complex even if it's not a chromorphore.

Design of Efficient Electroluminescent lanthanide(Ⅲ) Complexes

  • 유보라;김화중;박노길;김영식
    • Bulletin of the Korean Chemical Society
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    • 제22권9호
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    • pp.1005-1008
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    • 2001
  • The lanthanide complexes have been anticipated to exhibit high efficiency along with a narrow emission spectrum. Photoluminescence for the lanthanide complex is characterized by a high efficiency since both singlet and triplet excitons are involve d in the luminescence process. However, the maximum external electroluminescence quantum efficiencies have exhibited values around 1% due to triplet-triplet annihilation at high current. Here, we proposed a new energy transfer mechanism to overcome triplet-triplet annihilation by the Eu complex doped into phosphorescent materials with triplet levels that were higher than singlet levels of the Eu complex. In order to show the feasibility of the proposed energy transfer mechanism and to obtain the optimal ligands and host material, we have calculated the effect depending on ligands as a factor that controls emission intensity in lanthanide complexes. The calculation shows that triplet state as well as singlet state of anion ligand affects on absorption efficiency indirectly.

Bistability of $Co^{III}$(N-N)(3,6-DBSQ)(3,6-DBCat):Subtle Diimine Ligand Effect (N-N=4,7-Dimethyl-1,10-phenanthroline, 5-Chloro-1,10-phenanthroline;DBSQ=Di-tert-butylsemiquinonato;DBCat=Di-tert-butylcatecholato)

  • Ok-Sang Jung;Young-A Lee;Younkyoo Kim;Youn Soo Sohn
    • Bulletin of the Korean Chemical Society
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    • 제15권8호
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    • pp.641-643
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    • 1994
  • Studies of Co(N-N)(3,6-DBSQ)(3,6-DBCat)(N-N=4,7-dimethyl-1 ,10-phenanthroline, 5-chloro-1,10-phenanthroline; DBSQ=di-tert-butylsemiquinonato; DBCat=di-tert-butylcatecholato) have been carried out on the bistability by intramolecular cobalt-quinone electron transfer in solid state. The title complexes dominantly exist as $Co^{III}$(N-N)(3,6-DBSQ)(3,6-DBCat) at room temperature and display a significant bistability on temperature variation. Subtle change in optical spectra and magnetic properties is observed when diimine ligands are changed.

Luteolin Promotes Apoptosis of Endometriotic Cells and Inhibits the Alternative Activation of Endometriosis-Associated Macrophages

  • Woo, Jeong-Hwa;Jang, Dae Sik;Choi, Jung-Hye
    • Biomolecules & Therapeutics
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    • 제29권6호
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    • pp.678-684
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    • 2021
  • Luteolin, a flavonoid present in several fruits, vegetables, nuts, and herbs reportedly exhibits anti-cancer and anti-inflammatory properties. However, the effect of luteolin on endometriosis, a painful condition characterized by the ectopic growth of endometrial tissue and pelvic inflammation, remains elusive. Herein, we observed that luteolin inhibited cell growth and induced apoptosis of 12Z human endometriotic cells by activating caspase-3, -8, and -9. Additionally, luteolin significantly inhibited the expression of key chemokines, C-C motif chemokine ligand 2 (CCL2) and CCL5, required for monocyte/macrophage influx at endometriotic sites. In macrophages stimulated by endometriotic cells, luteolin treatment suppressed the intracellular expression of M2 markers and endometriosis-promoting factors. Collectively, our data suggest that luteolin exerts anti-endometriotic effects by stimulating endometriotic cell apoptosis and hindering the alternative activation of macrophages.

암세포 내로의 약물 전달 증진 목적의 신규 소마토스타틴 수용체 타겟리간드 합성 및 평가 (Synthesis and Evaluation of a Ligand Targeting the Somatostatin Receptor for Drug Delivery to Tumor Cell)

  • 최선주;홍영돈;이소영;정성희
    • 방사선산업학회지
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    • 제9권4호
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    • pp.193-198
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    • 2015
  • Most of targeted therapies block the action of certain enzymes, proteins, or other molecules involved in the growth and spread of cancer cells to produce its cytotoxic effect. Either small molecule drugs or monoclonal antibodies are mostly used in targeted therapies. Unfortunately, targeted therapy has a certain degree of unwanted side effect like other cytotoxicity inducing chemotherapies. To overcome and to reduce unwanted side effects during a cancer therapy, recently radiopeptide therapies has got the worlds' attraction for the tumor targeting modalities due to its beneficial effect on less side effect compared to cytotoxic chemotherapies. Among radiopeptide therapies, $^{177}Lu$-DOTATATE is a major modality as an effective one invented so far in treating neuroendocrine tumor (NET) and it has been in clinical trials at least one decade. Although it does have rather effective therapeutic effect on NET, it has less effective in rather large solid tumor. There are many ways to improve or increase therapeutic effect of radiopeptide are a finding the potent small molecules to target the tumor site selectively, or a labeling with radioisotope of emitting high energy, or an improving its biological half-life by introducing different moieties to increase lipophilicity. Present study was focus to increase a biological half-life of radio somatostatin which will target the somatostatin receptor by altering the bifunctional chelator (BFCA) by introducing lipophilic moiety to the somatostatin, which would make the labeled peptide stay longer in the tumor site and thus it can intensify the therapeutic effect on tumor cell itself and around tissues.

Inhibitory Effects of Saururus Chinensis Extracts on Osteoclast Differentiation

  • Shim, Ki-Shuk;Kim, Soon-Nam;Kim, Myung-Hee;Kim, Young-Sup;Ryu, Shi-Yong;Min, Yong-Ki;Kim, Seong-Hwan
    • Natural Product Sciences
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    • 제14권2호
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    • pp.113-117
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    • 2008
  • Saururus chinensis is a commonly used folk herb for the treatment of edema and liver diseases in Korea. To study the biological activity of Saururus chinensis in bone metabolism, we evaluated the effect of its extracts on osteoclast differentiation in vitro using primary mouse bone marrow-derived macrophages. Methanol extract (ME) from dried roots of Saururus chinensis was partitioned into methylene chloride (MF), ethyl acetate (EF), n-butanol (BF) and water fractions (WF). Tartrate-resistance acid phosphatase (TRAP) activity assay and western blot analysis were performed to determine the effect on osteoclast differentiation and mitogen-activated protein (MAP) kinases activation. ME, MF and EF dramatically inhibited receptor activator of ${NF-kB}$ ligand (RANKL)-induced formation of multinucleated osteoclasts and activation of MAP kinases. This study firstly demonstrated that ME, MF and EF of Saururus chinensis have the potential to inhibit the osteoclast differentiation, which results from the inhibition of MAP kinases activations in part.

TRAIL in Combination with Subtoxic 5-FU Effectively Inhibit Cell Proliferation and Induce Apoptosis in Cholangiocarcinoma Cells

  • Sriraksa, Ruethairat;Limpaiboon, Temduang
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권16호
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    • pp.6991-6996
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    • 2015
  • In the past decade, the incidence and mortality rates of cholangiocarcinoma (CCA) have been increasing worldwide. The relatively low responsiveness of CCA to conventional chemotherapy leads to poor overall survival. Recently, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL or Apo2L) has emerged as the most promising anti-cancer therapeutic agent since it is able to selectively induce apoptosis of tumor cells but not normal cells. In this study, we aimed to investigate the therapeutic effect of TRAIL in CCA cell lines (M213, M214 and KKU100) compared with the immortal biliary cell line, MMNK1, either alone or in combination with a subtoxic dose of 5-fluorouracil (5-FU). We found that recombinant human TRAIL (rhTRAIL) was a potential agent which significantly inhibited cell proliferation and mediated caspase activities (caspases 8, 9 and 3/7) and apoptosis of CCA cells. The combined treatment of rhTRAIL and 5-FU effectively enhanced inhibition of CCA cell growth with a smaller effect on MMNK1. Our finding suggests TRAIL to be a novel anti-cancer therapeutic agent and advantage of its combination with a conventional chemotherapeutic drug for effective treatment of CCA.

신경전달물질 및 물리적 자극에 대한 뼈 세포의 반응 (Bone Cell Response to Neurotransmitters and Mechanical Loading)

  • 곽지현;김병관;김경환;김지현
    • 대한의용생체공학회:의공학회지
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    • 제30권1호
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    • pp.89-93
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    • 2009
  • Bone remodeling is a continuous process of skeletal renewal during which bone formation is tightly coupled to bone resorption. Mechanical loading is an important regulator of bone formation and resorption. In recent studies, neurotransmitters such as vasoactive intestinal peptide (VIP) were found to be present inside bone tissue and have been suggested to potentially regulate bone remodeling. In this study, our objective was to use a pre-established in vitro oscillatory fluid flow-induced shear stress mechanical loading system to quantify the effect of VIP on bone resorptive activity and investigate its combined effect with mechanical loading. VIP decreased osteoclastogenesis significantly decreased RANKL/OPG mRNA ration by approximately 90%. Combined VIP and mechanical loading further decreased RANKL/OPG ratio to approximately 95%. These results suggest that VIP present in bone tissue may synergistically act with mechanical loading to regulate bone remodeling via suppression of bone resorptive activities.

치자 추출물이 RANKL 유도 파골세포 형성 및 골 흡수에 미치는 영향 (Effects of Gardeniae Jasminoides on RANKL-induced Osteoclastogenesis and Bone Resorption)

  • 최유경;황귀서
    • 대한한방내과학회지
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    • 제38권6호
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    • pp.1035-1048
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    • 2017
  • Objectives: This study was performed to investigate the effects of Gardenia jasminoides extract (GJ) on osteoclast differentiation and bone resorption in vitro. Methods: To investigate the effect of GJ on osteoclast differentiation, the mouse leukemic myeloid cell line RAW 264.7 was stimulated by RANKL (receptor activator of nuclear factor kB ligand). Osteoclast differentiation was measured by counting TRAP (+) MNC in the presence of RANKL. To elucidate the mechanism of the inhibitory effect of GJ on osteoclast differentiation, gene expression of TRAP, Cathepsin K, MMP-9, NFATc1, c-Fos, MITF, DC-STAMP, CTR, OC-STAMP and Atp6v0d2 was measured using reverse transcription-PCR (RT-PCR). Bone resorption was measured using the bone pit formation assay. Results: GJ decreased the number of TRAP (+) MNCs in the presence of RANKL. GJ inhibited the expression of cathepsin K, MMP-9, TRAP, MITF, NFATc1, c-Fos, iNON, OC-STAMP, Atp6v0d2, and DC-STAMP in the osteoclast, and inhibited bone pit formation in vitro. Conclusions: The results suggest that GJ has inhibitory effects on bone resorption resulting from inhibition of osteoclast differentiation and gene expression.