• Title/Summary/Keyword: Ligand effect

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Sex hormones alter the response of Toll-like receptor 3 to its specific ligand in fallopian tube epithelial cells

  • Zandieh, Zahra;Amjadi, Fatemehsadat;Vakilian, Haghighat;Aflatoonian, Khashayar;Amirchaghmaghi, Elham;Fazeli, Alireza;Aflatoonian, Reza
    • Clinical and Experimental Reproductive Medicine
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    • v.45 no.4
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    • pp.154-162
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    • 2018
  • Objective: The fallopian tubes play a critical role in the early events of fertilization. The rapid innate immune defense is an important part of the fallopian tubes. Toll-like receptor 3 (TLR3), as a part of the innate immune system, plays an important role in detecting viral infections. In this basic and experimental study, the effect of sex hormones on the function of TLR3 in the OE-E6/E7 cell line was investigated. Methods: The functionality of TLR3 in this cell line was evaluated by cytokine measurements (interleukin [IL]-6 and IL-1b) and the effects of sex hormones on TLR3 were tested by an enzyme-linked immunosorbent assay kit. Additionally, TLR3 small interfering RNA (siRNA) and a TLR3 function-blocking antibody were used to confirm our findings. Results: The production of IL-6 significantly increased in the presence of polyinosinic-polycytidylic acid (poly(I:C)) as the TLR3 ligand. Using a TLR3-siRNA-ransfected OE-E6/E7 cell line and function-blocking antibody confirmed that cytokine production was due to TLR3. In addition, 17-${\beta}$ estradiol and progesterone suppressed the production of IL-6 in the presence and absence of poly(I:C). Conclusion: These results imply that sex hormones exerted a suppressive effect on the function of TLR3 in the fallopian tube cell line when different concentrations of sex hormones were present. The current results also suggest that estrogen receptor beta and nuclear progesterone receptor B are likely to mediate the hormonal regulation of TLR3, as these two receptors are the main estrogen and progesterone receptors in OEE6/E7 cell line.

DA-6034 ameliorates hepatic steatosis and inflammation in high fat diet-induced obese mice

  • Hong Min Kim;Mi-Hye Kwon;Eun Soo Lee;Kyung Bong Ha;Choon Hee Chung
    • Journal of Yeungnam Medical Science
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    • v.41 no.2
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    • pp.103-112
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    • 2024
  • Background: Nonalcoholic fatty liver disease (NAFLD) is characterized by an increase in hepatic triglyceride content and increased inflammatory macrophage infiltration through the C-C motif chemokine receptor (CCR) 5 pathway in the liver. DA-6034 (7-carboxymethyloxy-3',4',5-trimethoxy flavone), is a synthetic derivative of eupatilin that exhibits anti-inflammatory activity in inflammatory bowel disease. However, the effect of DA-6034 on the inflammatory response in NAFLD is not well elucidated. Therefore, we aimed to determine the effect of DA-6034 on hepatic steatosis and inflammation. Methods: Forty male C57BL/6J mice were divided into the following four groups: (1) regular diet (RD), (2) RD with DA-6034, (3) high fat diet (HFD), and (4) HFD with DA-6034. All mice were sacrificed 12 weeks after the start of the experiment. The effects of DA-6034 on macrophages were assessed using RAW 264.7 cells. Results: DA-6034 not only reduced hepatic triglyceride levels and lipid accumulation but also macrophage infiltration and proinflammatory cytokines in HFD-fed mice. According to fluorescence-activated cell sorter analysis, DA-6034 reduced the CD8+ T cell fraction in the liver of HFD-fed mice. DA-6034 also reduced CCR5 expression and the migration of liver macrophages in HFD-fed mice and inhibited CCR2 ligand and CCR4 ligand, which stimulated the migration of macrophages. Conclusion: Overall, DA-6034 attenuates hepatic steatosis and inflammation in obesity by regulating CCR5 expression in macrophages.

Effect of PEG chain additive on 6,8-dichloro-2-phenylimidazo[1,2-a] pyridineacetamide (CB185) as a TSPO-binding ligand

  • Lee, Won Chang;Lee, Sang Hee;Denora, Nunzio;Laquintana, Valentino;Lee, Byung Chul;Kim, Sang Eun
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.5 no.2
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    • pp.89-100
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    • 2019
  • In our previous studies, we developed a 18F-labeled TSPO-binding ligand, named [18F]CB251, which has been proved to be a promising TSPO-binding PET radiotracer for the detection and monitoring of TSPO expression in pathological diseases. (Ki = 0.27 nM for TSPO, 1.96% ID/g of tumor uptake at 1h post-injection) Based on these results, we utilized 6,8-dichloro-2-phenylimidazo[1,2-a]pyridineacetamide analogs, CB185 (1) as a targeting moiety for the selective delivery of probes and anticancer molecules to TSPO-overexpressed tissues. In this study, we designed CB185 derivatives contains different PEG chains (n = 1, 3 and 5) and fluorescence dye (Cy5) to identify the necessary space between a TSPO-binding ligand and an anticancer agent. Three CB185 derivatives (11a-c) which contains Cy5 and PEG chain, were synthesized and the effect of PEG additive on their TSPO-binding affinities were evaluated using in vitro assays. The binding affinity for compounds 11a-c was lower than that of PK11195 (Ki = 3.2 nM), but still characterized by nanomolar binding affinity for TSPO (Ki = 46.5 nM for 11a, 51.0 nM for 11b, and 388.5 nM for 11c). These results showed that the conjugates are characterized by a moderate binding affinity toward TSPO except for compound 11c, which PEG chain consist of five PEG monomers. Our finding might add useful information to decide the appropriate PET chain length for developing new TSPO-targeting drug carriers.

Inhibitory Effect of Biotransformed-Fucoidan on the Differentiation of Osteoclasts Induced by Receptor for Activation of Nuclear Factor-κB Ligand

  • Park, Bobae;Yu, Sun Nyoung;Kim, Sang-Hun;Lee, Junwon;Choi, Sung Jong;Chang, Jeong Hyun;Yang, Eun Ju;Kim, Kwang-Youn;Ahn, Soon-Cheol
    • Journal of Microbiology and Biotechnology
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    • v.32 no.8
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    • pp.1017-1025
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    • 2022
  • Bone homeostasis is regulated by constant remodeling through osteogenesis by osteoblasts and osteolysis by osteoclasts and osteoporosis can be provoked when this balance is broken. Present pharmaceutical treatments for osteoporosis have harmful side effects and thus, our goal was to develop therapeutics from intrisincally safe natural products. Fucoidan is a polysaccharide extracted from many species of brown seaweed, with valuable pharmaceutical activities. To intensify the effect of fucoidan on bone homeostasis, we hydrolyzed fucoidan using AMG, Pectinex and Viscozyme. Of these, fucoidan biotransformed by Pectinex (Fu/Pec) powerfully inhibited the induction of tartrate-resistant acid phosphatase (TRAP) activity in osteoclasts differentiated from bone marrow macrophages (BMMs) by the receptor for activation of nuclear factor-κB ligand (RANKL). To investigate potential of lower molecular weight fucoidan it was separated into >300 kDa, 50-300 kDa, and <50 kDa Fu/Pec fractions by ultrafiltration system. The effects of these fractions on TRAP and alkaline phosphatase (ALP) activities were then examined in differentiated osteoclasts and MC3T3-E1 osteoblasts, respectively. Interestingly, 50-300 kDa Fu/Pec suppressed RANKL-induced osteoclasts differentiation from BMMs but did not synergistically enhance osteoblasts differentiation induced by osteogenic agents. In addition, this fraction inhibited the expressions of NFATc1, TRAP, OSCAR, and RANK, which are all key transcriptional factors involved in osteoclast differentiation, and those of Src, c-Fos and Mitf, as determined by RT-PCR. In conclusion, enzymatically low-molecularized 50-300 kDa Fu/Pec suppressed TRAP by downregulating RANKL-related signaling, contributing to the inhibition of osteoclasts differentiation, and represented a potential means of inducing bone remodeling in the background of osteoporosis.

The Effects of Phragmitis Rhizoma Herbal-acupuncture Solution on Inflammation in Human Mast Cells and Human Alveolar Epithelial Cell Lines - Phragmitis Rhizoma's Effects -

  • Kim, Byung-Soo
    • The Journal of Korean Medicine
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    • v.35 no.4
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    • pp.1-9
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    • 2014
  • Objectives: This study was designed to find the effect of Phragmitis Rhizoma (PR) herbal-acupuncture solution on the inflammatory cytokine and chemokine secretion in human mast cell (HMC) and human alveolar epithelial cell 549 (A549) lines. Methods: Histamine levels in HMC after PR herbal-acupuncture solution treatment were measured with ELISA. Other cytokines and chemokines levels such as interleukin 8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and chemokine (C-C motif) ligand 5 (Ccl5, RANTES) in A549 were measured with flow cytometry CBA system. Results: In the PR herbal-acupuncture solution treatment group, the expression of histamine, IL-8, MPC-1, Ccl5, and RANTES decreased significantly. Conclusions: The results support that PR herbal-acupuncture solution had a suppressive effect on cytokine-induced inflammation.

Cytokine Synergism in Apoptosis: Its Role in Diabetes and Cancer

  • Lee, Myung-Shik
    • BMB Reports
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    • v.35 no.1
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    • pp.54-60
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    • 2002
  • The effects of individual cytokine on apoptosis have been extensively studied. However, the effect of the cytokine combination, or the synergistic effect of cytokines on cell death, has not been widely studied, though synergism between cytokines has been documented in a variety of biological situations. In our effort to identify the final death effector molecule(s) in autoimmune diabetes, we inadvertently became interested in the cytokine synergism. We discovered that $IFN{\gamma}/TNF{\alpha}$ synergism, rather than the Fas ligand as currently believed, is responsible for the apoptosis of pancreatic islet cells both in vitro and in vivo. We also studied similar cytokine synergism in cancer cell deaths, and noted the similarities and dissimilarities between cancer cell death and islet cell death.

Apigenin Sensitizes Huh-7 Human Hepatocellular Carcinoma Cells to TRAIL-induced Apoptosis

  • Kim, Eun-Young;Kim, An-Keun
    • Biomolecules & Therapeutics
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    • v.20 no.1
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    • pp.62-67
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    • 2012
  • TNF-related apoptosis-inducing ligand (TRAIL) is a promising agent for management of cancer because of its selective cytotoxicity to cancer cells. However, some cancer cells have resistance to TRAIL. Accordingly, novel treatment strategies are required to overcome TRAIL resistance. Here, we examined the synergistic apoptotic effect of apigenin in combination with TRAIL in Huh-7 cells. We found that combined treatment of TRAIL and apigenin markedly inhibited Huh-7 cell growth compared to either agent alone by inducing apoptosis. Combined treatment with apigenin and TRAIL induced chromatin condensation and the cleavage of poly (ADP-ribose) polymerase (PARP). In addition, enhanced apoptosis by TRAIL/apigenin combination was quantified by annexin V/PI flow cytometry analysis. Western blot analysis suggested that apigenin sensitizes cells to TRAIL-induced apoptosis by activating both intrinsic and extrinsic apoptotic pathway-related caspases. The augmented apoptotic effect by TRAIL/apigenin combination was accompanied by triggering mitochondria-dependent signaling pathway, as indicated by Bax/Bcl-2 ratio up-regulation. Our results demonstrate that combination of TRAIL and apigenin facilitates apoptosis in Huh-7 cells.

Activation of Hypoxia Inducible Factor-1 Alpha by Estrogen Receptor Alpha (에스트로젠 수용체알파에 의한 Hypoxia Inducible Factor-1의 전사 활성조절)

  • Ryu, Kwang-Hee;Lee, Young-Joo
    • YAKHAK HOEJI
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    • v.54 no.2
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    • pp.102-105
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    • 2010
  • Our previous results showed that hypoxia inducible factor-1 (HIF-1) activated estrogen receptor (ER) in the absence of ligand. In this study, we have studied the effect ER overexpression on the activation of HIF-1. ER overexpression induced transcription activation of hypoxia response element driven luciferase and vascular endothelial growth factor. As a negative control, the effect of ER on androgen receptor response element was used. Our result indicate that the two ER$\alpha$ and HIF-1 signaling pathways shares part of the activation pathway.

Inhibitory Effects of Harmine on Migration and Invasion of Human Breast Cancer Cells by Regulating Notch Signaling (Harmine의 Notch 신호전달 조절에 의한 유방암세포주 이동 및 침윤 억제 효과)

  • Yun, Jieun
    • Korean Journal of Pharmacognosy
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    • v.49 no.4
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    • pp.285-290
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    • 2018
  • Harmine, a beta-carboline alkaloid isolated from the seeds of Peganum harmala has been reported as a promising drug candidate for cancer therapy. However, the effect of harmine on breast cancer remains still unclear. In this study, the effect of harmine on the cell proliferation, migration, and invasion of breast cancer MDA-MB231 cells and the underlying mechanism were investigated. The results indicated that harmine inhibited the proliferation MDA-MB231 cells in a dose-dependent manner and markedly suppressed migration and invasion of MDA-MB231 cells. The mechanism involved in part through Notch signaling. The Notch activity was significantly inhibited by harmine treatment and harmine suppressed the expression of Jagged1 which is a key ligand to activate Notch signaling. These findings suggest a novel mechanism of harmine on anti-cancer activity and harmine may act as a potential therapeutic drug for breast cancer treatment.

Inhibition of liver fibrosis by sensitization of human hepatic stellate cells by combined treatment with galtanin and TARIL

  • Dong-Oh Moon
    • Journal of Applied Biological Chemistry
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    • v.66
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    • pp.138-143
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    • 2023
  • Liver fibrosis is caused by metabolic problems such as cholestasis, genetic problems, or viral infections. Inhibiting hepatic stellate cell (HSC) activation or inducing selective apoptosis of activated HSCs is used as a treatment strategy for liver fibrosis. It has been reported that when HSCs are activated, their apoptosis sensitivity to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is enhanced because the expression of death receptor 5 is elevated. Finding a natural compound that can enhance the apoptotic effect of TRAIL on HSCs is a necessary strategy for liver fibrosis treatment. It was confirmed here that mangosteen-derived gartanin increased the effect of TRAIL-induced apoptosis by increasing the expression of DR5 in a p38-dependent manner in the hepatic stellate cell line LX-2. Combined treatment with gartanin and TRAIL accelerated DNA cleavage through caspase-3 activation and enhanced antifibrotic effects in LX-2 cells.