• Title/Summary/Keyword: downregulation

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Dandelion (Taraxacum officinale) Flower Ethanol Extract Inhibits Cell Proliferation and Induces Apoptosis in Human Ovarian Cancer SK-OV-3 Cells

  • Choi, Eun-Jeong;Kim, Gun-Hee
    • Food Science and Biotechnology
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    • v.18 no.2
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    • pp.552-555
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    • 2009
  • This study investigated the proapoptotic effect of ethanol extracts obtained from dandelion (Taraxacum officinale) flower on human ovarian cancer SK-OV-3 cells. Cells were treated with dandelion flowers ethanol extract (DFE) ranging from 1.5625 to $100{\mu}g/mL$ for 24 hr. Significant antiproliferative effects of DFE were first observed from at $6.25{\mu}g/mL$ (p<0.05), and this inhibition showed in a dose-dependent manner. When cells were treated with more than $6.25{\mu}g/mL$ DFE, cell-cycle analysis showed that DFE caused an increase in the percentage of sub-G0/G1 cells and arrested at the S and G2/M phase in a dose-dependent manner. Moreover, apoptosis induction by DFE involved p53 activation and bax upregulation as well as downregulation of bcl-2. Our findings indicate that DFE resulted in apoptotic cell death, suggesting that DFE possesses potential anticancer properties.

Microarray-Mediated Transcriptome Analysis of the Tributyltin (TBT)-Resistant Bacterium Pseudomonas aeruginosa 25W in the Presence of TBT

  • Dubey Santosh K.;Tokashiki Tsutomu;Suzuki Satoru
    • Journal of Microbiology
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    • v.44 no.2
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    • pp.200-205
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    • 2006
  • The tributyltin (TBT)-resistant bacterium, Pseudomonas aeruginosa 25W, which was isolated in seawater from the Arabian Sea, was subjected to transcriptome analysis in the presence of high concentrations of TBT. Only slight effects were observed at TBT concentration of $50{\mu}M$, but exposure to $500{\mu}M$ resulted in the upregulation of 6 genes and the downregulation of 75. Among the 75 downregulated genes, 53% (40 out of 75) were of hypothetical function, followed by 14 transcriptional regulation- and translation-associated genes. The results of this study indicated that although the 25W strain was highly resistant to TBT, high concentrations of TBT result in toxic effect on the transcriptional and translational levels. The target genes likely belong to a specific category of transcription- and translation-associated genes rather than to other gene categories.

IGF-I Exerts an Anti-inflammatory Effect on Skeletal Muscle Cells through Down-regulation of TLR4 Signaling

  • Lee, Won-Jun
    • IMMUNE NETWORK
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    • v.11 no.4
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    • pp.223-226
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    • 2011
  • Although exercise-induced growth factors such as Insulin-like growth factor-I (IGF-I) are known to affect various aspects of physiology in skeletal muscle cells, the molecular mechanism by which IGF-I modulates anti-inflammatory effects in these cells is presently unknown. Here, we showed that IGF-I stimulation suppresses the expression of toll-like receptor 4 (TLR4), a key innate immune receptor. A pharmacological inhibitor study further showed that PI3K/Akt signaling pathway is required for IGF-I-mediated negative regulation of TLR4 expression. Furthermore, IGF-I treatment reduced the expression of various NF-${\kappa}B$-target genes such as TNF-${\alpha}$ and IL-6. Taken together, these findings indicate that the anti-inflammatory effect of exercise may be due, at least in part, to IGF-I-induced suppression of TLR4 and subsequent downregulation of the TLR4-dependent inflammatory signaling pathway.

Critical Roles of Deubiquitinating Enzymes in the Nervous System and Neurodegenerative Disorders

  • Das, Soumyadip;Ramakrishna, Suresh;Kim, Kye-Seong
    • Molecules and Cells
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    • v.43 no.3
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    • pp.203-214
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    • 2020
  • Post-translational modifications play major roles in the stability, function, and localization of target proteins involved in the nervous system. The ubiquitin-proteasome pathway uses small ubiquitin molecules to degrade neuronal proteins. Deubiquitinating enzymes (DUBs) reverse this degradation and thereby control neuronal cell fate, synaptic plasticity, axonal growth, and proper function of the nervous system. Moreover, mutations or downregulation of certain DUBs have been found in several neurodegenerative diseases, as well as gliomas and neuroblastomas. Based on emerging findings, DUBs represent an important target for therapeutic intervention in various neurological disorders. Here, we summarize advances in our understanding of the roles of DUBs related to neurobiology.

Inhibition of Nelumbo nucifera Stamens-derived Kaempferol on FcεRI-mediated GATA-1 Expression

  • Shim, Sun-Yup
    • Microbiology and Biotechnology Letters
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    • v.47 no.3
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    • pp.350-353
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    • 2019
  • The transcription factor, GATA-1, plays an important role in the $Fc{\varepsilon}RI$ ${\alpha}$ chain expression in mast cells and basophils. This study was conducted to investigate the downregulation of the transcription factor GATA-1 by kaempferol isolated from Nelumbo nucifera stamens in $Fc{\varepsilon}RI$-mediated allergic reactions. Kaempferol inhibited $Fc{\varepsilon}RI$-mediated histamine release. Western blotting analysis and RT-PCR showed that the protein and mRNA expression of GATA-1 was suppressed by kaempferol in a dose-dependent manner. These results suggest that kaempferol may inactivate basophils by downregulating the $Fc{\varepsilon}RI$ ${\alpha}$ chain expression via the inhibition of the GATA-1 expression.

Inhibitory Activity of Wild-Simulated Ginseng against Non-Alcoholic Fatty Liver Disease in HepG-2 Cells

  • So Jung Park;Yurry Um;Min Yeong Choi;Jin Boo Jeong
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2023.04a
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    • pp.43-43
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    • 2023
  • In this study, we investigated in vitro inhibitory activity of wild-simulated ginseng (WSG) against non-alcoholic fatty liver disease using HepG-2 cells. T0901317 treatment increased the lipid accumulation in HepG-2 cells, but WSG treatment inhibited T0901317-mediated lipid accumulation. In addition, WSG downregulated T0901317-mediated expression of SREBP-1c, ACC, FAS and SCD-1 protein. In addition, WSG increased the phosphorylation level of LKB1 and AMPK. Compound C treatment blocked WSG-mediated downregulation of SREBP-1c protein. In conclusion, WSG is considered to inhibit the accumulation of lipids and triglycerides in HepG-2 cells by inducing the activation of LKB1 and AMPK successively, thereby reducing the expression of FAS, ACC, and SCD-1 through suppression of SREBP-1c expression.

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Methylanthranilate, a Food Fragrance Attenuates Skin Pigmentation through Downregulation of Melanogenic Enzymes by cAMP Suppression

  • Heui-Jin Park;Kyuri Kim;Eun-Young Lee;Prima F. Hillman;Sang-Jip Nam;Kyung-Min Lim
    • Biomolecules & Therapeutics
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    • v.32 no.2
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    • pp.231-239
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    • 2024
  • Methyl anthranilate (MA) is a botanical fragrance used in food flavoring with unexplored potential in anti-pigment cosmetics. MA dose-dependently reduced melanin content without affecting cell viability, inhibited dendrite elongation and melanosome transfer in the co-culture system of human melanoma cells (MNT-1) and human keratinocyte cell line (HaCaT), and downregulated melanogenic genes, including tyrosinase, tyrosinase-related protein 1 and 2 (TRP-1, TRP-2). Additionally, MA decreased cyclic adenosine monophosphate (cAMP) production and exhibited a significant anti-pigmentary effect in MelanodermTM. These results suggest that MA is a promising anti-pigmentary agent for replacing or complementing existing anti-pigmentary cosmetics.

Deciphering Macrophage Phenotypes upon Lipid Uptake and Atherosclerosis

  • Jihye Lee;Jae-Hoon Choi
    • IMMUNE NETWORK
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    • v.20 no.3
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    • pp.22.1-22.21
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    • 2020
  • In the progression of atherosclerosis, macrophages are the key immune cells for foam cell formation. During hyperlipidemic condition, phagocytic cells such as monocytes and macrophages uptake oxidized low-density lipoproteins (oxLDLs) accumulated in subintimal space, and lipid droplets are accumulated in their cytosols. In this review, we discussed the characteristics and phenotypic changes of macrophages in atherosclerosis and the effect of cytosolic lipid accumulation on macrophage phenotype. Due to macrophage plasticity, the inflammatory phenotypes triggered by oxLDL can be re-programmed by cytosolic lipid accumulation, showing downregulation of NF-κB activation followed by activation of anti-inflammatory genes, leading to tissue repair and homeostasis. We also discuss about various in vivo and in vitro models for atherosclerosis research and next generation sequencing technologies for foam cell gene expression profiling. Analysis of the phenotypic changes of macrophages during the progression of atherosclerosis with adequate approach may lead to exact understandings of the cellular mechanisms and hint therapeutic targets for the treatment of atherosclerosis.

Radix Sophorae Flavescentis inhibits proliferation and induces apoptosis of AGS human gastric cancer cells

  • Ji Sun Kim;Seung Jae Shin;Jung Nam Kim;Min Ji Kwon;Eun Yeong Lim;Yun Tai Kim;Hyungwoo Kim;Byung Joo Kim
    • Molecular Medicine Reports
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    • v.19 no.3
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    • pp.1911-1918
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    • 2019
  • Traditional herbal medicines are being increasingly used worldwide to treat cancer. Radix Sophorae Flavescentis (RSF) is a Chinese herb, which has numerous pharmacological properties, including anti-tumour effects. In this study, we investigated the mechanisms underlying RSF-induced apoptosis in human gastric cancer cells (AGS cells). We found that RSF treatment (20-200 ㎍/ml) inhibited the proliferation of AGS cells and increased the sub-G1 phase ratio. RSF-induced cell death was associated with the downregulation of BCl-2 and upregulation of Bax. In addition to increasing the expression levels of apoptosis-mediating surface antigen FAS and Fas ligand, RSF also activated caspase-3; however, mitogen-activated protein kinase appeared to inhibit RSF-induced cell death. RSF also led to an increased production of reactive oxygen species. Based on these results, we propose that RSF could be a potential therapeutic agent for gastric cancer.