• Title/Summary/Keyword: Fc receptor

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Kaempferol Isolated from Nelumbo nucifera Stamens Negatively Regulates $Fc{\varepsilon}RI$ Expression in Human Basophilic KU812F Cells

  • Shim, Sun-Yup;Choi, Jae-Sue;Byun, Dae-Seok
    • Journal of Microbiology and Biotechnology
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    • v.19 no.2
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    • pp.155-160
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    • 2009
  • Mast cells and basophils perform important functions as pivotal effector cells in IgE-mediated allergic reactions. KU812F cells, a human basophilic cell line isolated originally from chronic myelocytic leukemia, express a high affinity receptor of IgE, $Fc{\varepsilon}RI$. Kaempferol was extracted and isolated from a methanolic extract of flavonoid-rich Nelumbo nucifera stamens. In the present study, the inhibitory effects of kaempferol on $Fc{\varepsilon}RI$ expression in human basophilic KU812F cells was examined. Flow cytometric analysis revealed that $Fc{\varepsilon}RI$ expression on the cell surface was suppressed in a concentration-dependent manner when the cells were cultured with kaempferol. Moreover, RT-PCR analysis showed that the mRNA levels for $Fc{\varepsilon}RI$ ${\alpha}-\;and\;{\gamma}$-chains were reduced as the result of kaempferol treatment in a concentration-dependent manner. Kaempferol showed its suppressive effects on intracellular $Ca^{2+}$ concentration and histamine release from anti-$Fc{\varepsilon}RI$ ${\alpha}$-chain antibody-stimulated cells in a concentration-dependent manner. These observations indicate that kaempferol may exert antiallergic effect via down regulation of $Fc{\varepsilon}RI$ expression and degranulation.

Achyranthes japonica Nakai Water Extract Suppresses Binding of IgE Antibody to Cell Surface FcεRI.

  • Shim, Sun Yup;Lee, Mina;Lee, Kyung Dong
    • Preventive Nutrition and Food Science
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    • v.21 no.4
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    • pp.323-329
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    • 2016
  • Achyranthes japonica Nakai (AJN) water extract has a variety of physiological properties, including anti-diabetic, anti-cancer, anti-inflammatory, anti-microbial, and anti-oxidative activities. In the present study, the inhibitory effects of AJN extract were investigated in high affinity immunoglobulin E receptor ($Fc{\varepsilon}RI$)-mediated KU812F cells activation. AJN extract showed suppressive effects on histamine release and intracellular calcium [$Ca^{2+}$]i elevation from anti$Fc{\varepsilon}RI$ antibody (CRA-1)-stimulated cells in a dose-dependent manner. Flow cytometric analysis showed that AJN extract treatment caused a dose-dependent decrease in the cell surface $Fc{\varepsilon}RI$ expression and the binding between the cell surface $Fc{\varepsilon}RI$ and the IgE antibody. Moreover, reverse transcription-polymerase chain reaction analysis showed that levels of the mRNA for the $Fc{\varepsilon}RI$ ${\alpha}$ chain was decreased by treatment with AJN extract. These results indicate that AJN extract may exert anti-allergic effects via the inhibition of calcium influx and histamine release, which occurs as a result from the downregulation of the binding of IgE antibody to cell surface $Fc{\varepsilon}RI$. This mechanism may occur through $Fc{\varepsilon}RI$ expression inhibition.

Inhibitory Effects of Chrysanthemum zawadsaki Ethanolic Extract on $Fc{\varepsilon}RI$ ${\alpha}$ Chain Expression (구절초 에탄올 추출물의 $Fc{\varepsilon}RI$ ${\alpha}$ chain 발현 저해효과)

  • Shim, Sun-Yup;Byun, Dae-Seok
    • Korean Journal of Food Science and Technology
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    • v.43 no.2
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    • pp.220-223
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    • 2011
  • Human basophilic KU812F cells express a high affinity for IgE receptor, $Fc{\varepsilon}RI$, which plays an important role in immunoglobulin E (IgE)-mediated allergic reactions. Using the human basophilic KU812F cells, we assessed the inhibitory effects of the ethanolic extract from Chrysanthemum zawadsaki(CZ) on $Fc{\varepsilon}RI$ ${\alpha}$ chain expression. Flow cytometric analysis showed that cell surface $Fc{\varepsilon}RI$ ${\alpha}$ chain expression was suppressed when the cells were cultured with CZ extract. RT-PCR analysis showed that the mRNAs for $Fc{\varepsilon}RI$ ${\alpha}$ chain decreased by the treatment of CZ extract. Moreover, CZ extract was also observed to result in a reduction in the release of histamine from anti-$Fc{\varepsilon}RI$ antibody (CRA-1)-stimulated cells. These results suggest that CZ extract may exert anti-allergic activity through down-regulation of $Fc{\varepsilon}RI$ ${\alpha}$ chain expression and a subsequent decrease in histamine release.

Fumigaclavine C attenuates adipogenesis in 3T3-L1 adipocytes and ameliorates lipid accumulation in high-fat diet-induced obese mice

  • Yu, Wan-Guo;He, Yun;Chen, Yun-Fang;Gao, Xiao-Yao;Ning, Wan-E;Liu, Chun-You;Tang, Ting-Fan;Liu, Quan;Huang, Xiao-Cheng
    • The Korean Journal of Physiology and Pharmacology
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    • v.23 no.3
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    • pp.161-169
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    • 2019
  • Fumigaclavine C (FC), an active indole alkaloid, is obtained from endophytic Aspergillus terreus (strain No. FC118) by the root of Rhizophora stylosa (Rhizophoraceae). This study is designed to evaluate whether FC has anti-adipogenic effects in 3T3-L1 adipocytes and whether it ameliorates lipid accumulation in high-fat diet (HFD)-induced obese mice. FC notably increased the levels of glycerol in the culture supernatants and markedly reduced lipid accumulation in 3T3-L1 adipocytes. FC differentially inhibited the expressions of adipogenesis-related genes, including the peroxisome proliferator-activated receptor proteins, CCAAT/enhancer-binding proteins, and sterol regulatory element-binding proteins. FC markedly reduced the expressions of lipid synthesis-related genes, such as the fatty acid binding protein, lipoprotein lipase, and fatty acid synthase. Furthermore, FC significantly increased the expressions of lipolysis-related genes, such as the hormone-sensitive lipase, Aquaporin-7, and adipose triglyceride lipase. In HFD-induced obese mice, intraperitoneal injections of FC decreased both the body weight and visceral adipose tissue weight. FC administration significantly reduced lipid accumulation. Moreover, FC could dose-dependently and differentially regulate the expressions of lipid metabolism-related transcription factors. All these data indicated that FC exhibited anti-obesity effects through modulating adipogenesis and lipolysis.

Effects of enzymolysis and fermentation of Chinese herbal medicines on serum component, egg production, and hormone receptor expression in laying hens

  • Mei Hong Jiang;Tao Zhang;Qing Ming Wang;Jin Shan Ge;Lu Lu Sun;Meng Qi Li;Qi Yuan Miao;Yuan Zhao Zhu
    • Animal Bioscience
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    • v.37 no.1
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    • pp.95-104
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    • 2024
  • Objective: In the present study, we aimed to investigate the effects of enzymolysis fermentation of Chinese herbal medicines (CHMs) on egg production performance, egg quality, lipid metabolism, serum reproductive hormone levels, and the mRNA expression of the ovarian hormone receptor of laying hens in the late-laying stage. Methods: A total of 360 Hy-Line Brown laying hens (age, 390 days) were randomly categorized into four groups. Hens in the control (C) group were fed a basic diet devoid of CHMs, the crushed CHM (CT), fermented CHM (FC), and enzymatically fermented CHM (EFT) groups received diets containing 2% crushed CHM, 2% fermented CHM, and 2% enzymatically fermented CHM, respectively. Results: Compared with crushed CHM, the acid detergent fiber, total flavonoids, and total saponins contents of fermented CHM showed improvement (p<0.05); furthermore, the neutral and acid detergent fiber, total flavonoids, and total saponins contents of enzymatically fermented CHM improved (p<0.05). At 5 to 8 weeks, hens in the FC and EFT groups showed increased laying rates, haugh unit, albumin height, yolk color, shell thickness, and shell strength compared with those in the C group (p<0.05). Compared with the FC group, the laying rate, albumin height, and Shell thickness in the EFT group was increased (p<0.05). Compared with the C, CT, and FC groups, the EFT group showed reduced serum total cholesterol and increased serum luteinizing hormone levels and mRNA expressions of follicle stimulating hormone receptor and luteinizing hormone receptor (p<0.05). Conclusion: These results indicated that the ETF group improved the laying rate and egg quality and regulated the lipid metabolism in aged hens. The mechanism underlying this effect was likely related to cell wall degradation of CHM and increased serum levels of luteinizing hormone and mRNA expression of the ovarian hormone receptor.

Suppressive Effects of Scutellaria radix Water Extract on $Fc{\varepsilon}RI$ Expression

  • Shim, Sun-Yup;Byun, Dae-Seok;Kim, Hyeung-Rak;Lee, Kyung-Dong;Cho, Young-Sook
    • Food Science and Biotechnology
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    • v.15 no.5
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    • pp.694-697
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    • 2006
  • The initiation of immunoglobulin E (IgE)-mediated allergic reactions requires binding of IgE antibody to its high-affinity receptor. Human basophilic KU812F cells express $Fc{\varepsilon}RI$ on the cell surface and act as effector cells in the allergic response. In this study, we investigated the effects of Scutellaria radix extract on the expression of the $Fc{\varepsilon}RI$ in human KU812F cells. Flow cytometric analysis showed that S. radix extract treatment caused a concentration-dependent decrease in $Fc{\varepsilon}RI$ expression on the cell surface. Furthermore, the level of $Fc{\varepsilon}RI$ ${\alpha}$, ${\beta}$, and ${\gamma}$ chain mRNA in KU812F cells was examined by RT-PCR. S. radix extract reduced total cellular $Fc{\varepsilon}RI$ $\alpha$ and ${\gamma}$ chain mRNA expression in a concentration-dependent manner. $Fc{\varepsilon}RI$-mediated histamine release was reduced from $21.75{\pm}1.34\;ng/10^6$ cells in non-treated cells to $16.46{\pm}1.98\;ng/10^6$ cells in S. radix extract treated cells. These results suggested that S. radix extract has the potential to down-regulate of FcRI expression and to inactivate basophils.

Inhibitory Effects of Paeonia suffruticosa Andrews Extracts on VEGF Binding to VEGF Receptor

  • Lee, Hak-Kyo;Lee, Sung-Jin
    • Natural Product Sciences
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    • v.13 no.2
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    • pp.128-131
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    • 2007
  • Tumor angiogenesis is a critical step f3r the growth and metastasis of solid tumors. Vascular endothelial growth factor (VEGF) is the most important angiogenic molecule associated with tumor-induced neovascularization. VEGF exerts its activity through binding to its receptor tyrosine kinase, KDR/Flk-1, expressed on the surface of endothelial cells. This study was carried out to investigate inhibitory effect of extracts from root cortex of Paeonia suffruticosa Andrews on VEGF binding to VEGF receptor. The MeOH extract from P. suffrutiocosa Andr. inhibited the binding of KDR/Flk-1-Fc to immobilized VEGF$_{165}$ more than 45% at the concentration of 100 ${\mu}$g/mL. The MeOH extract was further fractionated into n-hexane, ethyl acetate, n-BuOH, and aqueous fractions. Among the four fractions, the ethyl acetate fraction from the root cortex of P. suffruticosa Andr. exhibited highly effective inhibition (${\approx}$ 79% inhibition) and then n-BuOH fraction (${\approx}$ 45% inhibition) on the binding of KDR/Flk-1-Fc to immobilized VEGF$_{165}$ at the concentration of 100 ${\mu}$g/mL. The ethyl acetate fraction from the root cortex of P. suffruticosa Andr. more efficiently blocked VEGF-induced human umbilical vein endothelial cell proliferation, than the growth of HT1080 human fibrosarcoma. Our results suggest that P. suffruticosa Andr. may be used as a candidate fur developing anti-angiogenic agent.

The $Fc{\gamma}$ receptor III genotype as a risk factor for aggressive periodontitis in Korean patients (한국인 급진성 치주염 환자의 위험요소로서 $Fc{\gamma}$ III 수용기의 유전형)

  • Kim, Myung-Hyun;Shin, Seung-Yun;Kim, Tae-Il;Seol, Yang-Jo;Lee, Yong-Moo;Rhyu, In-Chul;Chung, Chong-Pyoung;Han, Soo-Boo;Ku, Young
    • Journal of Periodontal and Implant Science
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    • v.36 no.1
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    • pp.113-123
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    • 2006
  • 연구배경 IgG에 대한 $Fc{\gamma}$ 수용기는 치주병인균에 대한 숙주 반응에 있어서 중요한 역할을 하는데, 이 중 $Fc{\gamma}RIIIa$는 NK 세포, 대식세포, 단핵구, ${\gamma}{\delta}T$세포에서 발현되며, EC2 도메인에서 158 아미노산 부위의 valine (V)-phenylalanine (F)의 유전자다형성을 보인다. $Fc{\gamma}RIIIb$는 특이적으로 중성구에 발현되는데, extracellular (ECl) Ig-like 도메인 내 4개의 아미노산 치환(substitutions)에 의한 NA1-NA2 유전자다형성을 보인다. 이 연구의 목적은 한국인에서 급진성 치주염 환자와 $Fc{\gamma}III$ 수용기의 유전자다형성과의 관련성을 알아보는 것이다. 연구방법 및 재료 치주적으로 건강한 90명 (대조군, 남자 64명, 여자 26명)과 서울대학교 치과병원 지주과에 내원하여 급진성 치주염으로 진단된 환자 43명 (aggressive periodontitis patients: AgP, 남자 30명, 여자 13명)을 대상으로 하였다. 모든 실험 대상자는 임상 실험에 대해 동의 하였고, 초진 시 전자 탐침(Florida Probe(R) Co. Gainesville, FL)을 이용하여 탐침 시 치주낭 깊이 (PPD), 임상부착수준 (CAL), 치태지수(PI), 탐침 후 출혈지수 (BOP)를 측정하였다. 또한 이들의 정맥혈에서 추출한 DNA를 PCR법, 전기영동법 등을 이용하여 $Fc{\gamma}RIIIa$, $Fc{\gamma}RIIIb$의 대립 유전자의 존재여부를 확인하였다. 이를 바탕으로 $Fc{\gamma}RIII$ 복합 유전형을 확인하여 각 군 간을 비교하였다. 연구 결과 1. $Fc{\gamma}RIIIa$에 대한 유전자다형성 연구 결과 대조군과 급진성 치주염 환자 군(AgP)사이에서는 대립 유전자 분포가 서로 유의성 있는 차이를 나타내었고 (P<0.05), $Fc{\gamma}RIIIb$에서는 유의성 있는 차이를 발견할 수 없었다. (P>0.05) 2. $Fc{\gamma}RIIIa$ 158F 대립형질이 급진성 치주염 환자에서 유의성 있게 많이 발견되어졌다. (P<0.05) 결론 이 연구를 통하여 $Fc{\gamma}RIIIa$ 유전자의 분석이 한국인의 급진성 치주염에 대한 감수성의 위험요소의 표지자로 활용할 수 있을 것으로 사료되며, 향 후 더 많은 환자를 대상으로 히는 추가 연구가 필요하다고 생각된다.

Sanguiin H-6 Blocks Endothelial Cell Growth through Inhibition of VEGF Binding to VEGF Receptor

  • Lee Sung-Jin;Lee Hak-Kyo
    • Archives of Pharmacal Research
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    • v.28 no.11
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    • pp.1270-1274
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    • 2005
  • The vascular endothelial growth factor (VEGF) plays a key role in angiogenesis, which is a process where new blood vessels develop from the endothelium of a pre-existing vasculature. VEGF exerts its activity by binding to its receptor tyrosine kinase, KDR/Flk-1, which is expressed on the surface of endothelial cells. A methanol extract and organic solvent (n-hexane, ethyl acetate, n-butanol, aqueous) fractions from Rubus coreanus were examined for their inhibitory effects on VEGF binding to the VEGF receptor. The methanol extract from the crude drug were found to significantly inhibit VEGF binding to the VEGF receptor ($IC_{50}$$\thickapprox$27 $\mu$g/mL). Among the fractions examined, the aqueous fraction from the medicinal plant showed potent inhibitory effects against the binding of KDR/Flk-1-Fc to immobilized $VEGF_{165}$ in a dose­dependent manner ($IC_{50}$$\thickapprox$11 $\mu$g/mL). Sanguiin H-6 was isolated as an active principle from the aqueous fraction, and inhibited the binding of KDR/Flk-1-Fc to immobilized $VEGF_{165}$ in a dose­dependent manner ($IC_{50}$$\thickapprox$0.3 $\mu$g/mL). In addition, sanguiin H-6 efficiently blocked the VEGF­induced HUVEC proliferation in a dose-dependent manner ($IC_{50}$$\thickapprox$7.4 $\mu$g/mL) but had no effect on the growth of HT1080 human fibrosarcoma cells. This suggests that sanguiin H-6 might be a potential anti-angiogenic agent.