• Journal of Marine Bioscience and Biotechnology
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• v.2 no.2
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• pp.81-85
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• 2007

Glucocorticoid hormone regulates numerous physiological processes, such as regulation of metabolism, and anti-inflammatory and immunosuppressive actions via the activation and repression of gene expression. Here we described a lentivirus-based reporter vector system expressing red fluorescent protein (mRFP) or firefly luciferase (Luc) under the control of a glucocorticoid-responsive element that allows observation of the temporospatial pattern of glucocorticoid induced GR-mediated signaling on a cellular level. Moreover, usage of the chromatin insulator of the chicken ${\beta}$-globin locus induced a marked increase of sensitivity of glucocorticoid inducible promoter of a reporter gene. Use of this method will be applicable of screening for agonist and antagonist of GR in vitro, and also a reporter gene assay for the in vivo determination of the GR-mediated gene activation.

• Molecules and Cells
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• v.41 no.5
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• pp.423-435
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• 2018

This investigation was aimed at working out the combined role of lncRNA H19, miR-29b and Wnt signaling in the development of colorectal cancer (CRC). In the aggregate, 185 CRC tissues and corresponding para-carcinoma tissues were gathered. The human CRC cell lines (i.e. HT29, HCT116, SW480 and SW620) and normal colorectal mucosa cell line (NCM460) were also purchased. Si-H19, si-NC, miR-29b-3p mimics, miR-29b-3p inhibitor, si-PGRN and negative control (NC) were, respectively, transfected into the CRC cells. Luciferase reporter plasmids were prepared to evaluate the transduction activity of $Wnt/{\beta}-catenin$ signaling pathway, and dual-luciferase reporter gene assay was arranged to confirm the targeted relationship between H19 and miR-29b-3p, as well as between miR-29b-3p and PGRN. Finally, the proliferative and invasive capacities of CRC cells were appraised through transwell, MTT and scratch assays. As a result, overexpressed H19 and down-expressed miR-29b-3p displayed close associations with the CRC patients' poor prognosis (P < 0.05). Besides, transfection with si-H19, miR-29b-3p mimic or si-PGRN were correlated with elevated E-cadherin expression, decreased snail and vimentin expressions, as well as less-motivated cell proliferation and cell metastasis (P < 0.05). Moreover, H19 was verified to directly target miR-29b-3p based on the luciferase reporter gene assay (P < 0.05), and miR-29b-3p also bound to PGRN in a direct manner (P < 0.05). Finally, addition of LiCl ($Wnt/{\beta}-catenin$ pathway activator) or XAV93920 ($Wnt/{\beta}-catenin$ pathway inhibitor) would cause remarkably altered E-cadherin, c-Myc, vimentin and snail expressions, as well as significantly changed transcriptional activity of ${\beta}-catenin/Tcf$ reporter plasmid (P < 0.05). In conclusion, the lncRNA H19/miR-29b-3p/PGRN/Wnt axis counted a great deal for seeking appropriate diagnostic biomarkers and treatment targets for CRC.

• Nutrition Research and Practice
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• v.14 no.5
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• pp.453-462
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• 2020

BACKGROUND/OBJECTIVES: Platycodon grandiflorum (PG), an oriental herbal medicine, has been known to improve liver function, and has both anti-inflammatory and antimicrobial properties. However, little is known about the immune-enhancing effects of PG and its mechanism. In this study, we aimed to investigate whether fermented PG extract (FPGE), which has increased platycodin D content, activates the immune response in a murine macrophage cell line, RAW 264.7. MATERIALS/METHODS: Cell viability was determined by Cell Counting Kit-8 assay and the nitric oxide (NO) levels were measured using Griess reagent. Cytokine messenger RNA levels of were monitored by quantitative reverse transcription polymerase chain reaction. To investigate the molecular mechanisms underlying immunomodulatory actions of FPGE in RAW 264.7 cells, we have conducted luciferase reporter gene assay and western blotting. RESULTS: We found that FPGE treatment induced macrophage cell proliferation in a dose-dependent manner. FPGE also modulated the expression of NO and pro-inflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. The activation and phosphorylation levels of nuclear factor kappa B (NF-κB) were increased by FPGE treatment. Moreover, 5-aminoimidazole-4-carboxamide ribonucleotide, an activator of AMP-activated kinase (AMPK), significantly reduced both lipopolysaccharides- and FPGE-induced NF-κB reporter gene activity. CONCLUSIONS: Taken together, our findings suggest that FPGE may be a novel immune-enhancing agent acting via AMPK-NF-κB signaling pathway.

• Tuberculosis and Respiratory Diseases
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• v.55 no.5
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• pp.488-498
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• 2003

Background : Activation of the transcription factor NF-${\kappa}B$ has been shown to protect cells from tumor necrosis factor-alpha, chemotherapy, and radiation-induced apoptosis. NF-${\kappa}B$-dependent cIAP expression is a major antiapoptotic mechanism for that. NF-${\kappa}B$ activation and cIAP expression in A549 lung cancer cells which is relatively resistant to radiation-induced cell death were investigated for the mechanism of radioresistance. Materials and methods : We used A549 lung cancer cells and Clinac 1800C linear accelerator for radiation. Cell viability test was done by MTT assay. NF-${\kappa}B$ activation was tested by luciferase reporter gene assay, Western blot for $I{\kappa}B{\alpha}$ degradation, and electromobility shift assay. For blocking ${\kappa}B$, MG132 and transfection of $I{\kappa}B{\alpha}$-superrepressor plasmid construct were used. cIAP expression was analyzed by RT-PCR and cIAP2 promoter activity was performed using luciferase assay system. Results : MTT assay showed that cytotoxicity even 48 hr after radiation in A549 cells were less than 20%. Luciferas assay demonstrated weak NF-${\kappa}B$ activation of $1.6{\pm}0.2$ fold compared to PMA-induced $3.4{\pm}0.9$ fold. Radiation-induced $I{\kappa}B{\alpha}$ degradation was observed in Western blot and NF-${\kappa}B$ DNA binding was confirmed by EMSA. However, blocking NF-${\kappa}B$ using MG132 and $I{\kappa}B{\alpha}$-superrepressor transfection did not show any sensitizing effect for radiation-induced cell death. The result of RT-PCR for cIAP1 & 2 expression was negative induction while TNF-${\alpha}$ showed strong expression for cIAP1 & 2. The cIAP2 promoter activity also did not show any change compared to positive control with TNF-${\alpha}$. Conclusion : We conclude that activation of NF-${\kappa}B$ does not determine the intrinsic radiosensitivity of cancer cells, at least for the cell lines tested in this study.

• Animal cells and systems
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• v.15 no.3
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• pp.227-233
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• 2011

The Nramp1/Slc11a1 locus encodes a proton-coupled divalent cation transporter, expressed in late endosomes/lysosomes of macrophages, that constitutes a component of the innate immune response to combat intracellular pathogens and it was shown to play an important role in regulating inherent immunity. The previously identified Z-DNA forming polymorphic repeat(GT)n in the promoter region of the human Nramp1 gene does act as a functional polymorphism influencing gene expression. Research has shown that INF-${\gamma}$, TNF-${\alpha}$, IL-$1{\beta}$ and bacteria LPS increase the level of Nramp1 expression. However, the molecular mechanism for Nramp1 gene regulation is unclear. In this research, bovine Nramp1 5'-flanking region (-1748~+769) was cloned and analyzed by bioinformatics. Then to find the core promoter and the cis-acting elements, deletion analysis of promoter was performed using a set of luciferase reporter gene constructs containing successive deletions of the bovine Nramp1 5'-flanking regions. Promoter activity analysis by the dual luciferase reporter assay system showed that the core promoter of Nramp1 was located at +58~-89 bp. Some positive regulatory elements are located at -89~-205 bp and -278~-1495 bp. And the repressor elements were in region -205~-278 bp, intron1 and -1495~-1748 bp. LPS-responsive regions were located at -1495~-1748 bp and -278~-205 bp. The present study provides an initial effort to explore the molecular mechanism of transcriptional activation of the bovine Nramp1 gene and should facilitate further studies to decode the complex regulatory process and for molecular breeding for disease resistance in bovines.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.3
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• pp.265-273
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• 2024

This study aims to explore possible effect of RNA polymerase I subunit D (POLR1D) on proliferation and angiogenesis ability of colorectal cancer (CRC) cells and mechanism herein. The correlation of POLR1D and Yin Yang 1 (YY1) expressions with prognosis of CRC patients in TCGA database was analyzed. Quantitative realtime polymerase chain reaction (qRT-PCR) and Western blot were applied to detect expression levels of POLR1D and YY1 in CRC cell lines and CRC tissues. SW480 and HT-29 cells were transfected with si-POLR1D or pcDNA3.1-POLR1D to achieve POLR1D suppression or overexpression before cell migration, angiogenesis of human umbilical vein endothelial cells were assessed. Western blot was used to detect expressions of p38 MAPK signal pathway related proteins and interaction of YY1 with POLR1D was confirmed by dual luciferase reporter gene assay and chromatin immunoprecipitation (ChIP). TCGA data showed that both POLR1D and YY1 expressions were up-regulated in CRC patients. High expression of POLR1D was associated with poor prognosis of CRC patients. The results showed that POLR1D and YY1 were highly expressed in CRC cell lines. Inhibition or overexpression of POLR1D can respectively suppress or enhance proliferation and angiogenesis of CRC cells. YY1 inhibition can suppress CRC progression and deactivate p38 MAPK signal pathway, which can be counteracted by POLR1D overexpression. JASPAR predicted YY1 can bind with POLR1D promoter, which was confirmed by dual luciferase reporter gene assay and ChIP. YY1 transcription can up-regulate POLR1D expression to activate p38 MAPK signal pathway, thus promoting proliferation and angiogenesis ability of CRC cells.

• Biomedical Science Letters
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• v.10 no.2
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• pp.137-142
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• 2004

The peroxisome proliferator-activated receptor $\gamma$ (PPAR${\gamma}$) is the molecular target for a class of drugs, the antidiabetic thiazolidnediones (TZDs). The heterodimer of PPAR${\gamma}$ with retinoid X receptor (RXR) plays a central role in the regulation of adipogenesis and insulin sensitization. We synthesized two chemicals, DANA87 and DANA88, sharing structural characteristics with TZDs. Given this structural similarity, it was hypothesized that DANA87 and DANA88 may act as PPAR$\gamma$ ligands. In transient transfection assays, DANA87 and DANA88 caused slight increases in the endogenous expression of a luciferase reporter gene containing the PPAR responsive element in 3T3-L1 preadipocytes. However, DANA87 and DANA88 significantly inhibited troglitazone-induced reporter gene activation when cells were treated with a combination of DANA87 or DANA 88 and troglitazone, one of the TZDs that activate PPAR$\gamma$. These results suggest that DANA87 and DANA88 are not only weak agonists of PPAR${\gamma}$ transactivation, but also competitively antagonize troglitazone-induced PPAR$\gamma$ reporter activity.

• Animal cells and systems
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• v.4 no.4
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• pp.389-394
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• 2000

The Tcf-1 (1-cell factor-1) protein binds to the T-cell specific enhancer sequences and plays an architectural role in the assembly of transcriptional machinery. One of the Tcf family proteins, Tcf-4, was found to be an important regulator for colon cancer development where it activates specific genes upon binding to $\beta$-catenin following Wnt signaling. We were interested in the transcriptional regulatory activities of Tcf-1 and Tcf-4 proteins in T-cells and colon cancer cells. Transactivation assay was developed using a reporter plasmid containing luciferase gene under the control of Tcf responsive elements. Luciferase activity was determined following co-transfection of the reporter along with Tcf-1 and/or $\beta$-catenin expressing plasmids. Transcription was significantly induced by $\beta$-catenin expression in all cells. Tcf-1 by itself did not induce transcription in the mature T-cell lines, but overexpressed Tcf-1 greatly activated transcription in the immature T-cell line. In addition, transfected $\beta$-catenin induced apoptosis, but co-transfected Tcf-1 suppressed apoptosis in HEK293 cells. These results suggest that Tcf-1 and $\beta$-catenin differently regulate transcription and apoptosis.

• Journal of Ginseng Research
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• v.44 no.5
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• pp.690-696
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• 2020

Background: As the main metabolites of ginsenosides, 20(S, R)-protopanaxadiol [PPD(S, R)] and 20(S, R)-protopanaxatriol [PPT(S, R)] are the structural basis response to a series of pharmacological effects of their parent components. Although the estrogenicity of several ginsenosides has been confirmed, however, the underlying mechanisms of their estrogenic effects are still largely unclear. In this work, PPD(S, R) and PPT(S, R) were assessed for their ability to bind and activate human estrogen receptor α (hERα) by a combination of in vitro and in silico analysis. Methods: The recombinant hERα ligand-binding domain (hERα-LBD) was expressed in E. coli strain. The direct binding interactions of ginsenosides with hERα-LBD and their ERα agonistic potency were investigated by fluorescence polarization and reporter gene assays, respectively. Then, molecular dynamics simulations were carried out to simulate the binding modes between ginsenosides and hERα-LBD to reveal the structural basis for their agonist activities toward receptor. Results: Fluorescence polarization assay revealed that PPD(S, R) and PPT(S, R) could bind to hERα-LBD with moderate affinities. In the dual luciferase reporter assay using transiently transfected MCF-7 cells, PPD(S, R) and PPT(S, R) acted as agonists of hERα. Molecular docking results showed that these ginsenosides adopted an agonist conformation in the flexible hydrophobic ligand-binding pocket. The stereostructure of C-20 hydroxyl group and the presence of C-6 hydroxyl group exerted significant influence on the hydrogen bond network and steric hindrance, respectively. Conclusion: This work may provide insight into the chemical and pharmacological screening of novel therapeutic agents from ginsenosides.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.113-113
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• 2001

Stable MCF-7-ERE cells, in which pERE-Luc reporter gene has been stably integrated into the genome of the MCF-7 cells, were used to detect the estrogenic activity of various dietary flavonoids in either pure chemical or mixtures. Estradiol (E2) induced luciferase activity in dose dependent manner and this activity was inhibited by tamoxifen (Tam) concomitant treatment. A large series of flavonoids showed estrogenic activities, corresponding to EC5O values between 0.2 and 9 microM and their mixtures didn't show additive or synergistic effects. And we could find some structure and activity relationship. First, 4-methoxylation and catechol structure decreased estrogenic activities. Second, hydroxylation of 3 position reduced estrogenic effect. Third glycosides of flavonoids showed weak estrogenic activity or no activity. Interestingly, when tested at high concentrations, genistein, kaempferol, biochanin A and chrysin elicited luciferase induction higher than that of the maximum induction by estradiol. And these effects of genistein and kaempferol could not be fully inhibited with tamoxifen