• Food Science and Biotechnology
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• v.15 no.2
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• pp.303-307
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• 2006

Effect of Oenanthe javanica ethanol extract (OJE) on nuclear factor-${\kappa}B$ (NF-${\kappa}B$)-mediated inflammatory reaction in RAW 264.7 macrophage cells was investigated. The OJE dose-dependently inhibited secretions of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and prostaglandins $E_2\;(PGE_2)$ from lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and blocked LPS-induced expression of cyclooxygenase-2. To clarify mechanistic basis for its inhibitions of NF-${\kappa}B$ and activator protein-1 (AP-1) activations, effects of OJE on activations of NF-${\kappa}B$ and AP-1 genes by luciferase reporter activity were examined. The LPS-stimulated activations of NF-${\kappa}B$ and AP-1 were significantly blocked by 400 and $600\;{\mu$}g/mL of OJE, implicating that OJE might regulate gene expression through more than one signaling pathway. Cytosolic degradation of I-${\kappa}B{\alpha}$ was inhibited by OJE dose-dependently, indicating that the nuclear translocation of p65 was inhibited by OJE. These findings suggest that the inhibition of LPS-stimulated COX-2 expression by OJE is due to its inhibition of NF-${\kappa}B$ activation by blocking I-${\kappa}B{\alpha}$ degradation, which may be mechanistic basis of anti-inflammatory effects of OJE.

• Biomolecules & Therapeutics
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• v.21 no.6
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• pp.487-492
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• 2013

Cytochrome P450 4A11 (CYP4A11) is a fatty acid hydroxylase enzyme expressed in human liver. It catalyzes not only the hydroxylation of saturated and unsaturated fatty acids, but the conversion of arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE), a regulator of blood pressure. In this study, we performed a directed evolution analysis of CYP4A11 using the luminogenic assay system. A random mutant library of CYP4A11, in which mutations were made throughout the entire coding region, was screened with luciferase activity to detect the demethylation of luciferin-4A (2-[6-methoxyquinolin-2-yl]-4,5-dihydrothiazole-4-carboxylic acid) of CYP4A11 mutants in Escherichia coli. Consecutive rounds of random mutagenesis and screening yielded three improved CYP4A11 mutants, CP2600 (A24T/T263A), CP2601 (T263A), and CP2616 (A24T/T263A/V430E) with ~3-fold increase in whole cells and >10-fold increase in purified proteins on the luminescence assay. However, the steady state kinetic analysis for lauric acid hydroxylation showed the significant reductions in enzymatic activities in all three mutants. A mutant, CP2600, showed a 51% decrease in catalytic efficiency ($k_{cat}/K_m$) for lauric acid hydroxylation mainly due to an increase in $K_m$. CP2601 and CP2616 showed much greater reductions (>75%) in the catalytic efficiency due to both a decrease in $k_{cat}$ and an increase in Km. These decreased catalytic activities of CP2601 and CP2616 can be partially attributed to the changes in substrate affinities. These results suggest that the enzymatic activities of CYP4A11 mutants selected from directed evolution using a luminogenic P450 substrate may not demonstrate a direct correlation with the hydroxylation activities of lauric acid.

• Food Science of Animal Resources
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• v.30 no.5
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• pp.787-794
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• 2010

Calcium plays a role as a signaling molecule in various cellular events. It has been reported that calcium suppresses adipocyte differentiation only in the early phase of adipogenesis. Herein, we demonstrate that treatment of A23187, a mobilizer of intracellular calcium, on day 4 post adipocyte differentiation could still reduce lipid accumulation in differentiating 3T3-L1 cells for 48 h. In addition, luciferase reporter gene and RT-Q-PCR assays demonstrate that A23187 can selectively inhibit transcriptional activities and expression of PPAR$\gamma$ and LXR$\alpha$, suggesting that A23187 may reduce lipid accumulation in the late phase of adipogenesis via downregulation of PPAR$\gamma$ and LXR$\alpha$ expression and transactivation. Moreover, inhibition of HDAC activity by trichostatin A (TSA) partially blocked A23187-mediated downregulation of transcriptional activities of PPAR$\gamma$ and LXR$\alpha$. Together, our data demonstrate that calcium mobilization inhibits expression and transcriptional activities of PPAR$\gamma$ and LXR$\alpha$, resulting in reduced lipid accumulation in differentiating adipocytes, and thus, mobilization of intracellular calcium in adipocytes may serve as a new preventive and therapeutic approach for obesity.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.4937-4944
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• 2015

MicroRNAs (miRNAs) are emerging as critical regulators in carcinogenesis and tumor progression. Recently, miR-99a has been reported as a tumor suppressor gene in various human cancers, but its functions in the context of anaplastic thyroid cancer (ATC) remain unknown. In this study, we reported that miR-99a was commonly downregulated in ATC tissue specimens and cell lines with important functional consequences. Overexpression of miR-99a not only dramatically reduced ATC cell viability by inducing cell apoptosis and accumulation of cells at G1 phase, but also inhibited tumorigenicity in vivo. We then screened and identified a novel miR-99a target, mammalian target of rapamycin (mTOR), and it was further confirmed by luciferase assay. Up-regulation of miR-99a would markedly reduce the expression of mTOR and its downstream phosphorylated proteins (p-4E-BP1 and p-S6K1). Similar to restoring miR-99a expression, mTOR down-regulation suppressed cell viability and increased cell apoptosis, whereas restoration of mTOR expression significantly reversed the miR-99a antitumor activity and the inhibition of mTOR/p-4E-BP1/p-S6K1 signal pathway profile. In clinical specimens and cell lines, mTOR was commonly overexpressed and its protein levels were statistically inversely correlated with miR-99a expression. Taken together, our results demonstrated for the first time that miR-99a functions as a tumor suppressor and plays an important role in inhibiting the tumorigenesis through targeting the mTOR/p-4E-BP1/p-S6K1 pathway in ATC cells. Given these, miR-99a may serve as a novel prognostic/diagnostic and therapeutic target for treating ATC.

• BMB Reports
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• v.44 no.12
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• pp.816-820
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• 2011

There is a broad range of different small heat shock proteins (sHSPs) that have diverse structural and functional characteristics. To better understand the functional role of mitochondrial sHSP, NtHSP24.6 was expressed in Escherichia coli with a hexahistidine tag and purified. The protein was analyzed by non-denaturing PAGE, chemical cross-linking and size exclusion chromatography and the $H_6NtHSP24.6$ protein was found to form a dimer in solution. The in vitro functional analysis of $H_6NtHSP24.6$ using firefly luciferase and citrate synthase demonstrated that this protein displays typical molecular chaperone activity. When cell lysates of E. coli were heated after the addition of $H_6NtHSP24.6$, a broad range of proteins from 10 to 160 kD in size remained in the soluble state. These results suggest that NtHSP24.6 forms a dimer and can function as a molecular chaperone to protect a diverse range of proteins from thermal aggregation.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.4
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• pp.292-299
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• 2019

Interferon tau (IFNT) regulation, an anti-luteolytic factor produced by conceptuses of the ruminant ungulates, is essential for the maintenance of early pregnancy, but a definitive mechanism for its temporal transcription has not been elucidated. We and others have observed the T-box protein eomesodermin (EOMES) exhibited high mRNA expression in the ovine embryonic trophectoderm; thus, both caudal-relatedhomeobox-2 (CDX2) and EOMES coexist during the early stages of conceptus development. Objective of this study was to examine the effect of EOMES on ovine IFNT gene transcription when evaluated with CDX2, ETS2 and AP1 transcription factors implicated in the control of cell differentiation in the trophectoderm. In this study, quantitatively via reverse transcription-polymerase chain reaction (RT-PCR) analysis between ovine trophoblast cells was initially performed, finding that transcription factors CDX2 and 'EOMES transcription factor mRNAs' were specific to trophectoderm cells. These mRNAs were also found in days 15, 17, and 21 ovine conceptuses. Furthermore, human choriocarcinoma JEG3 cells (trophoblast cell line) were cotransfected with an ovine IFNT (-654bp)-luciferase reporter (-654-oIFNT-Luc) construct and several transcription factor expression plasmids. Cotransfection of the reporter construct with CDX2, ETS2 and AP1 increased transcription of -654-oIFNT-Luc by about 11-fold compared with transfection of the construct alone. When cells were initially transfected with EOMES followed by transfection with CDX2, ETS2 and/or AP1, the expression of -654-oIFNT-Luc was decreased. Also, EOMES factor inhibited the stimulatory activity of CDX2 alone. These results suggest that when conceptuses attach to the uterine epithelium, ovine IFNT gene transcription is down-regulated by an increase of EOMES factor expression in the attached ovine trophoblast cells.

• Toxicological Research
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• v.31 no.1
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• pp.11-16
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• 2015

Our body's immune system has defense mechanisms against pathogens such as viruses and bacteria. Immune responses are primarily initiated by the activation of toll-like receptors (TLRs). In particular, TLR4 is well-characterized and is known to be activated by gram-negative bacteria and tissue damage signals. TLR4 requires myeloid differentiation factor 2 (MD2) as a co-receptor to recognize its ligand, lipopolysaccharides (LPS), which is an extracellular membrane component of gram-negative bacteria. Gambogic acid is a xanthonoid isolated from brownish or orange resin extracted from Garcinia hanburyi. Its primary effect is tumor suppression. Since inflammatory responses are related to the development of cancer, we hypothesized that gambogic acid may regulate TLR4 activation. Our results demonstrated that gambogic acid decreased the expression of pro-inflammatory cytokines ($TNF-{\alpha}$, IL-6, IL-12, and $IL-1{\beta}$) in both mRNA and protein levels in bone marrow-derived primary macrophages after stimulation with LPS. Gambogic acid did not inhibit the activation of Interferon regulatory factor 3 (IRF3) induced by TBK1 overexpression in a luciferase reporter gene assay using IFN-${\beta}$-PRD III-I-luc. An in vitro kinase assay using recombinant TBK1 revealed that gambogic acid did not directly inhibit TBK1 kinase activity, and instead suppressed the binding of LPS to MD2, as determined by an in vitro binding assay and confocal microscopy analysis. Together, our results demonstrate that gambogic acid disrupts LPS interaction with the TLR4/MD2 complex, the novel mechanism by which it suppresses TLR4 activation.

• Toxicological Research
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• v.23 no.3
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• pp.231-238
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• 2007

Evaluation of potentials of chemicals to alter expression of genes that are involved in carcinogenesis may serve useful tools in toxicological research. In this investigation, we developed reporter cell lines that expressed luciferase in response to transactivation of hypoxia inducible factor-1, P53 tumor suppressor and Nur77 of which roles have been well established in cancer development and progression. Whereas these reporter cell lines displayed low constitutive backgrounds, the reporter activities were significantly enhanced in response to $desferriosamine/CoCl_2$, adriamycin or 6-mercaptopurine, which are hypoxia mimicking chemicals, P53 activator or Nur77 inducer, respectively. The activation of the reporter was time- and dose-dependent. Known tumor initiators and promoters, such as phorbol 12-myristate 13-acetate and phorbol 12, 13-dicaprinate induced the reporter activity at as low as 10nM in these stable cell lines. Further, known anti-tumor promoters, such as ascorbic acid and ${\beta}-carotene$ repressed the reporter activities. These results indicate that our stable reporter cell lines could serve as a useful system for rapid assessment of carcinogenicity of toxic chemicals.

• Toxicological Research
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• v.30 no.1
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• pp.19-25
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• 2014

Licochalcone (LC), a major phenolic retrochalcone from licorice, has anti-inflammatory activity. This study investigated the effects of licochalcone A (LCA) and licochalcone E (LCE) on Liver X receptor-${\alpha}$ ($LXR{\alpha}$)-mediated lipogenic gene expression and the molecular mechanisms underlying those effects. LCA and LCE antagonized the ability of $LXR{\alpha}$ agonists (T0901317 or GW3965) to increase sterol regulatory element binding protein-1c (SREBP-1c) expression and thereby inhibited target gene expression (e.g., FAS and ACC) in HepG2 cells. Moreover, treatment with LCA and LCE impaired $LXR{\alpha}/RXR{\alpha}$-induced CYP7A1-LXRE-luciferase (CYP7A1) transactivation. The AMPK-Sirt1 signaling pathway is an important regulator of energy metabolism and, therefore, a potential therapeutic target for metabolic diseases, including hepatic steatosis. We found here that LCE increased AMPK phosphorylation and Sirt1 expression. We conclude that LC inhibits SREBP-1c-mediated hepatic lipogenesis via activation of the AMPK/Sirt1 signaling pathway.

• Journal of Sasang Constitutional Medicine
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• v.21 no.1
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• pp.139-149
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• 2009

1. Objectives The roots of Sophora flavescens Aiton (SFA) are widely used as a herbal remedy for allergic inflammation. In this study, we invested the effect of SFA on passive cutaneous anaphylaxis reaction and histamin releas and we demonstrated that SFA suppressed the production of pro-inflammatory cytokines, such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin- 6 (IL-6), and interleukin -8 (IL-8), through inhibition of the $NF{\kappa}B$, JNK and p38 pathway in the human mast cell line, HMC-1. 2. Methods To accomplish this, we invested passive cutaneous anaphylaxis reaction and histamin release at an animal experiment. In addition, we investigated the effect of SFA on the production of inflammation-related cytokines in HMC-1 cells that were co-treated with PMA and A23187, which can induce production of pro-inflammatory cytokines. 3. Results and Conclusions SFA induced passive cutaneous anaphylaxis reaction and histamin releas and supressed the expression of TNF-${\alpha}$, IL-6, and IL-8. In addition, the protein levels of TNF-${\alpha}$ were also decreased by SFA treatment. Furthermore, SFA inhibited the nuclear translocation of nuclear factor $NF{\kappa}B$ through inhibition of the phosphorylation and degradation of $I{\kappa}B-{\alpha}$, which is an inhibitor of $NF{\kappa}B$. Moreover, SFA also inhibited induction of MAPKs (JNK, p38) and $NF{\kappa}B$ promoter-mediated luciferase activity. Taken together, these results suggest that SFA could be used as a treatment for mast cell-derived allergic inflammatory diseases.