• Animal cells and systems
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• v.16 no.2
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• pp.87-94
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• 2012

Nur77 is a member of the nuclear receptor 4A (NR4A) subgroup, which has been implicated in energy metabolism. Although Nur77 is found in adipose tissue, where TR4 plays a key role in lipid homeostasis, the role of Nur77 in adipogenesis is still controversial. Although the Nur77 responsive element (AAAGGTCA) is partially overlapped with TR4-binding sites (AGGTCA $n$ AGGTCA: $n$=0-6), the regulatory role of Nur77 in TR4 function associated with adipocyte biology remains unclear. Here, we found that Nur77 inhibits adipogenesis and TR4 transcriptional activity. Treatment with a Nur77 agonist, 1,1-bis(3'-indolyl)-1-($p$-anisyl)-methane, during 3T3-L1 adipocyte differentiation reduced adipogenesis. In reporter gene analysis, Nur77 specifically suppressed TR4 transcription activity but had little effect on $PPAR{\gamma}$ transcription activity. Consistently, Nur77 also suppressed TR4-induced promoter activity of the TR4 target gene PEPCK, which is known to be important for glyceroneogenesis in adipose tissue. Furthermore, Nur77 suppressed TR4 binding to TR4 response elements without direct interaction with TR4, suggesting that Nur77 may inhibit TR4 transcription activity via binding competition for TR4-binding sites. Furthermore, DIM-C-$pPhOCH_3$ substantially suppressed TR4-induced PEPCK expression in 3T3-L1 adipocytes. Together, our data demonstrate that Nur77 plays an inhibitory role in TR4-induced PEPCK expression in 3T3-L1 adipocytes.

• BMB Reports
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• v.29 no.3
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• pp.221-224
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• 1996

To examine the growth-phase dependent control of Escherichia coli rnpB gene we used a combination of Northern analysis for RNA determination and Southern analysis for plasmid DNA determination. The relative amounts of metabolically unstable transcript derived from the internally deleted rnpB gene harbored on a multicopy plasmid as well as the relative plasmid contents were measured by Northern analysis and Southern analysis, respectively, of total nucleic acids from E coli cells containing the plasmid. The relative transcription activity of the rnB was represented by a ratio of the relative amount of the transcript to that of the plasmid DNA during bacterial growth. The rnpB transcription increased rapidly with time during exponential growth, but started to decrease before the transition period of an exponential growing cell culture into the stationary phase. Although the expression pattern was similar to the changes of ${\beta}-galactosidase$ activity expressed from the lysogenic strain carrying the chromosomal rnpB-lacZ fusion which were shown in a previous work, the present data appears to represent a more actual growth-phase control of the rnpB transcription than the previous data by the ${\beta}-galactosidase$ assay. In addition the present method described for a direct analysis of both RNA and plasmid DNA provides a rapid and efficient method that can applied to an examination of transcription control by using a multicopy plasmid.

• BMB Reports
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• v.56 no.9
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• pp.508-513
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• 2023

The phytochemical quercetin has gained attention for its anti-inflammatory and anti-tumorigenic properties in various types of cancer. Tumorigenesis involves the aberrant regulation of kinase/phosphatase, highlighting the importance of maintaining homeostasis. Dual Specificity Phosphatase (DUSP) plays a crucial role in controlling the phosphorylation of ERK. The current study aimed to clone the DUSP5 promoter, and investigate its transcriptional activity in the presence of quercetin. The results revealed that quercetin-induced DUSP5 expression is associated with the serum response factor (SRF) binding site located in the DUSP5 promoter. The deletion of this site abolished the luciferase activity induced by quercetin, indicating its vital role in quercetin-induced DUSP5 expression. SRF protein is a transcription factor that potentially contributes to quercetin-induced DUSP5 expression at the transcriptional level. Additionally, quercetin enhanced SRF binding activity without changing its expression. These findings provide evidence of how quercetin affects anti-cancer activity in colorectal tumorigenesis by inducing SRF transcription factor activity, thereby increasing DUSP5 expression at the transcriptional level. This study highlights the importance of investigating the molecular mechanisms underlying the anti-cancer properties of quercetin, and suggests its potential use in cancer therapy.

• The Journal of Natural Sciences
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• v.14 no.1
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• pp.51-61
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• 2004

T7 RNA polymerase is a single subunit RNA polymerase able to accomplish whole transcription process without auxiliary factors. T7 phage lysozyme involcing in destruction of host cell wall repress T7 transcription and affects transcription termination process. Therefore expression vector pT7lys containing T7 phage lysozyme gene was constructed and expressed. T7 phage lysozyme protein was purified to homogeneity by Ni-NTA column chromatography. Also amidase activity of the purified lysozyme was identified. In order to understand the effect of the lysozyme on the sequence specific transcription termination. T7 transcription elongation complexes at the site rrnB T1 transcription termination signal were made in the presence the lysozyme. The results shows that the transcription elongation complexes are unstable in the presence of T7 phage lysozyme.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.70-70
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• 2003

Estrogen receptor is a ligand-activated transcription factor. Its action depends on the receptor, its ligand, and its coactivator proteins. As a consequence, the concentration of the receptor is a major component that governs the magnitude of the estrogen response. Despite the extensive knowledge on mechanism of estrogen receptor action, regulation of estrogen receptor itself is not very well understood. Estrogen receptor is known to be downregulated under hypoxia leading to inhibition of estrogen receptor mediated transcription activation. We have studied mechanism of loss of estrogen responsiveness under hypoxia. We found that Hif-l${\alpha}$, a major transcription factor regulating hypoxic response, inhibited transcription of estrogen response element driven luciferase gene by expression of HIF-l${\alpha}$/vp16 construct designed to contain transcription activity under normoxia. This loss of estrogen responsiveness appears to be the result of ER${\alpha}$ downregulation. ER${\alpha}$was downregulated at the levels of ligand-biding and protein within l2-24h, and the response was blocked by the proteasome inhibitor MG132, protein synthesis inhibitor cyclohexamide, and tyrosine kinase inhibitor Genistein. These results demonstrate that Hif-l${\alpha}$ downregulates ER${\alpha}$ by proteasome dependent pathway.

• 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.

• IMMUNE NETWORK
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• v.16 no.3
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• pp.176-182
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• 2016

CCR3 is a chemokine receptor that mediates the accumulation of allergic inflammatory cells, including eosinophils and Th2 cells, at inflamed sites. The regulatory sequence of the CCR3 gene, contains two Runt-related transcription factor (RUNX) 1 sites and two PU.1 sites, in addition to a functional GATA site for transactivation of the CCR3 gene. In the present study, we examined the effects of the cis-acting elements of RUNX1 and PU.1 on transcription of the gene in EoL-1 eosinophilic cells and Jurkat T cells, both of which expressed functional surface CCR3 and these two transcription factors. Introduction of RUNX1 siRNA or PU.1 siRNA resulted in a modest decrease in CCR3 reporter activity in both cell types, compared with transfection of GATA-1 siRNA. Cotransfection of the two siRNAs led to inhibition in an additive manner. EMSA analysis showed that RUNX1, in particular, bound to its binding motifs. Mutagenesis analysis revealed that all point mutants lacking RUNX1- and PU.1-binding sites exhibited reduced reporter activities. These results suggest that RUNX1 and PU.1 participate in transcriptional regulation of the CCR3 gene.

• Nutrition Research and Practice
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• v.6 no.6
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• pp.499-504
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• 2012

This study attempted to investigate the effects of resveratrol on the differentiation of adipocytes. After cells were treated with various concentrations of resveratrol (0, 10, 20, and 40 ${\mu}mol/L$), adipocyte proliferation, the protein expression of transcription factors, and MMPs' activities were determined. Cell proliferation was inhibited more within 4 days of incubation (P<0.05), and lipid accumulation in adipocyte was significantly inhibited by 93.8%, 92.4% and 91.5%, respectively, after two days of 10, 20, and 40 ${\mu}mol/L$ resveratrol treatment (P<0.05). Six days of incubation with the three resveratrol concentrations caused a significantly decreases of 63%, 59.9%, and 25.1% GPDH activity as a dose-dependent response. The triglyceride concentration also decreased significantly with the increase of resveratrol concentration (P<0.05). The protein expression of CCAAT/enhancer-binding protein (C/$EBP{\beta}$) was decreased significantly by 56% and 30% while $PPAR{\gamma}$ was significantly reduced by 57% and 15% with resveratrol treatments of 20 and 40 ${\mu}mol/L$, respectively (P<0.05). The protein expression of C/$EBP{\alpha}$ was decreased by 83%, 74%, and 38% to increased dosage levels, with significance determined for this decrease from 20 ${\mu}mol/L$ of resveratrol. The protein expression of fatty acid binding protein (FABP4) was decreased significantly by 88%, 72%, and 46% with the increase of resveratrol concentration. The activity of MMP-2 was decreased significantly by 84%, 70%, and 63% while MMP-9 activity was decreased significantly by 74%, 62%, and 39% with the increased resveratrol concentrations of 10, 20, and 40 ${\mu}mol/L$, respectively (P<0.05).

• Korean Journal of Pharmacognosy
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• v.53 no.2
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• pp.102-110
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• 2022

Alzheimer's disease (AD) is the most common form of dementia, and the accumulation of β-amyloid (Aβ) in the brain triggers AD, followed by hyperphosphorylation of tau protein, neurofibrillary tangles, and synapses loss, neuronal cell death, and cognitive decline occur in a chain. In APPswe neuronal cell line, 50 ㎍/ml of Campbell early (Vitis labruscana B.) leaves 50% ethanol extract (VLL) treatment inhibited the secretion of Aβ1-42 by about 63% and the secretion of Aβ1-40 by about 50%. VLL did not target the enzymatic activity of the amyloidogenic pathway and decreased the protein expression of APP. As a result of RT-qPCR (Reverse transcription-quantitative real-time PCR) of the APPswe cell line treated with VLL, it is thought that the protein expression of APP was reduced by inhibiting the transcription process of the APP gene. In addition, VLL inhibited acetylcholinesterase (AChE) enzyme activity in vitro by 27.6% and 54.7%, respectively, at 50 and 100 ㎍/ml concentrations. We found that VLL inhibited the production of Aβ, a dementia-inducing substance, by suppressing the transcription of the APP gene, and that VLL inhibited AChE activity. We suggest that VLL has the potential as a natural drug material that modulates the alleviation of dementia symptoms.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.501-508
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• 2011

Previous studies suggest that polyunsaturated fatty acids with long carbon chains such as eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) have several health benefits. However metabolic consequences of these fatty acids themselves and their regulation of transcriptional activity involving glucose utilization are not well established. Thus, the purpose of this study was to investigate how EPA influx affects cellular lipid accumulation and gene expressions involving $de$ $novo$ lipogenesis in hepatocyte cultures. Compared to oleic acid treatment, EPA treatment showed remarkably decreased cellular TG conversion and accumulation, along with phospholipids at a lower extent. As expected, EPA increased mRNA expression involving fatty acid influx and lipid droplet formation, but did not affect mRNA expression involving glucose utilization. EPA increased transcriptional activity of PPAR-${\alpha}$ and glucose responsive transcription factor when transcription factor binding protein was activated. Taken together, these data suggest that EPA decreases lipid accumulation through increases of the ${\beta}$-oxidation pathway without interruption of glucose utilization.