• Title/Summary/Keyword: Ligand effect

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Relationships of the Lithium-Induced Growth Inhibition of C6 Rat Glioma Cell to Expression of the Insulin-like Growth Factor System Components (C6 Rat Glioma Cell에서 리튬에 의한 성장 억제와 Insulin-like Growth Factor System Components의 발현과의 관계)

  • Kim, I.A.;Jin, E.J.;Cho, E.J.;Sohn, S.H.;Lee, C.Y.
    • Journal of Animal Science and Technology
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    • v.46 no.4
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    • pp.563-570
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    • 2004
  • The insulin-like growth factor(IGF) system, consisting of IGFs-I and -II ligands and their receptors and six IGF-binding proteins(IGFBPs), plays an important role in survival, proliferation and differentiation of a variety of cell types. Lithium is a known modulator of survival and proliferation of many cell types in vitro. The present study was undertaken to investigate the relationship between LiCI-induced changes in cell survival and growth and the expression of the IGF system components in C6 rat glioma cell line which, besides IGF-I and its receptor, is known to express IGFBP-3 as its major IGF carrier. When C6 cells were cultured for 24h in the absence or presence of 2mM or 5mM LiCl in a 10% serwn-containing medium, the viability and the number of cells were not affected by added lithium. In 72-h culture, however, C6 cells clearly exhibited a dose-dependent response to added LiCl. The cells cultured for 72h in the presence of 0, 2mM and 5mM LiCl exhibited a typical mitotic, a growth-arrested and an apoptotic appearances, respectively. Moreover, the apoptotic cells were accompanied by reduced expression of IGF-I, IGF-I receptor and IGFBP-3 as examined by semi-quantitative reverse transcription-polymerase chain reaction. Interestingly, blockade of IGFBP-3 mRNA translation by addition of 101${\mu}M$ IGFBP-3 anti-sense oligodeoxyribonucleotide in serum-free, 24-h culture resulted in a decrease in the number of cells as well as relative abundance of the target mRNA. In summary, results suggest that the cytotoxic effect of lithium in C6 cell is likely to be mediated, in part, by suppression by this agent of the expression of the IGF system components. In this regard, IGFBP-3 may play at least a 'permissive' role in normal proliferation of this cell.

Quercetin suppress CCL20 by reducing IκBα/STAT3 phosphorylation in TNF-α/IL-17A induced HaCaT cells (TNF-α/IL-17A 유도된 HaCaT 세포주에서 Quercetin의 IκBα/STAT3 인산화 조절에 의한 CCL20 발현 억제)

  • Kim, Mi Ran;Kim, Min Young;Hwang, Hyung Seo
    • Journal of Applied Biological Chemistry
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    • v.63 no.3
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    • pp.211-219
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    • 2020
  • Quercetin is a polyphenol compound with excellent antioxidant and anti-inflammatory activity. However, little has been reported about the efficacy of quercetin to control psoriasis. Thus, we aimed to investigate the effect of quercetin to regulate psoriatic dermatitis with HaCaT cell lines activated by TNF-α and IL-17A, which are in vitro psoriasis skin models. When quercetin was treated with TNF-α-activated HaCaT cell line, inflammatory cytokine expressions such as IL-1α, IL-1β and IL-6 were reduced by 49.1±7.14, 42.8±8.16, and 34.5±2.52%, respectively. In addition, mRNA expression levels of IL-8 and CCL20 the chemokines that attract immune cells such as Th17 cells and dendritic cells to the inflammatory reaction site, were also reduced by 38.4±5.83 and 52.9±4.59% compared to the TNF-α treatment group. The expression of proteins KRT6A and KRT16, which was nonspecifically increased in psoriatic skin was also significantly suppressed. Moreover, phosphorylation of IκBα and STAT3 proteins activated by TNF-α was also significantly inhibited. After stimulating the HaCaT with IL-17A, known as another psoriasis-inducing cytokine, it was observed that IκBα mRNA expression decreased by 55.8±5.28%, and STAT3 phosphorylation was downregulated by 36.3±6.81%. Finally, after co-activation by TNF-α/IL-17A, quercetin inhibited all of IL-1α, IL-1β, IL-6, TNF-α and CCL20 gene expression. The above results strongly suggest that quercetin is a material that has not only anti-oxidant and anti-inflammatory activities, but also has an activity in improving psoriasis.

An IRS Study on the Adsorption of Carbonmonoxide on Silica Supported Ni-Cu Alloys (실리카 지지 니켈-구리 합금에서 일산화탄소의 흡착에 관한 IRS 연구)

  • Ahn, Jeong-Soo;Yoon, Koo-Sik;Park, Sang-Youn;Park, Sung-Kyun
    • Journal of the Korean Chemical Society
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    • v.53 no.3
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    • pp.233-243
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    • 2009
  • We have investigated the infrared spectra for CO adsorbed on silica supported nickel(Ni-Si$O_2$), silica supported copper(Cu-Si$O_2$), silica supported nickel-copper alloys(Ni/Cu-Si$O_2$) of several compositions with varying CO pressures(0.2 $torr{\sim}$50 torr) at room temperature and on pumping to vacumn at room temperature within the frequency range of 1500 $cm^{-1}{\sim}2500\;cm^{-1}$. Four bands(2059.6 $cm^{-1},\;{\sim}$2036.5 $cm^{-1},\;{\sim}$ 1868.7 $cm^{-1},\;{\sim}$ 1697.1 $cm^{-1}$) were observed for Ni-Si$O_2$, two bands($\sim$2115.5 $cm^{-1},\;{\sim}$1743.0 $cm^{-1}$) were observed for Cu-Si$O_2$ and five bands(${\sim}2123.2\;cm^{-1}$, 2059.6 $cm^{-1},\;{\sim}$2036.4 $cm^{-1},\;{\sim}$1899.5 $cm^{-1},\;{\sim}$1697.1 $cm^{-1}$) were observed for Ni/Cu-Si$O_2$. These absorption bands correspond with those of the previous reports approximately. The bands below 1800 $cm^{-1}$ were only observed with Ni metal or Ni/Cu alloy crystal plane containing step at room temperature and the ${\sim}1697.1\;cm^{-1}$ bands observed with Ni-Si$O_2$ and Ni/Cu-Si$O_2$ may be ascribed to CO molecule adsorbed on the adsorption sites near step. The bands below 2000 $cm^{-1}$ were rarely observed with Cu metal crystal plane at room temperature and the 1743.0 $cm^{-1}$ bands may be ascribed to CO molecule adsorbed on the adsorption sites near step. The band shifts of adsorbed CO with varing Cu contents from 0 to 0.5 mole fraction at the same CO pressure or at the same pumping time to vacumn were below 21 $cm^{-1}$. and comparatively small than those with other ⅠB metal addition. It may means ligand effect of Cu d electron is small.