• Title/Summary/Keyword: transcription activator

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3-Deoxysappanchalcone Promotes Proliferation of Human Hair Follicle Dermal Papilla Cells and Hair Growth in C57BL/6 Mice by Modulating WNT/β-Catenin and STAT Signaling

  • Kim, Young Eun;Choi, Hyung Chul;Lee, In-Chul;Yuk, Dong Yeon;Lee, Hyosung;Choi, Bu Young
    • Biomolecules & Therapeutics
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    • v.24 no.6
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    • pp.572-580
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    • 2016
  • 3-Deoxysappanchalcone (3-DSC) has been reported to possess anti-allergic, antiviral, anti-inflammatory and antioxidant activities. In the present study, we investigated the effects of 3-DSC on the proliferation of human hair follicle dermal papilla cells (HDPCs) and mouse hair growth in vivo. A real-time cell analyzer system, luciferase assay, Western blot and real-time polymerase chain reaction (PCR) were employed to measure the biochemical changes occurring in HDPCs in response to 3-DSC treatment. The effect of 3-DSC on hair growth in C57BL/6 mice was also examined. 3-DSC promoted the proliferation of HDPCs, similar to Tofacitinib, an inhibitor of janus-activated kinase (JAK). 3-DSC promoted phosphorylation of ${\beta}$-catenin and transcriptional activation of the T-cell factor. In addition, 3-DSC potentiated interleukin-6 (IL-6)-induced phosphorylation and subsequent transactivation of signal transducer and activator of transcription-3 (STAT3), thereby increasing the expression of cyclin-dependent kinase-4 (Cdk4), fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF). On the contrary, 3-DSC attenuated STAT6 mRNA expression and IL4-induced STAT6 phosphorylation in HDPCs. Finally, we observed that topical application of 3-DSC promoted the anagen phase of hair growth in C57BL/6 mice. 3-DSC stimulates hair growth possibly by inducing proliferation of follicular dermal papilla cells via modulation of $WNT/{\beta}$-catenin and STAT signaling.

Paw Edema was Reduced in Carrageenan Induced Acute Inflammation in Stat4 Deficient Mice

  • Zheng, Long-Tai;Baik, Haing-Woon;Lee, Seong-Kyu;Cho, Jeong-Je;Park, Cheung-Seog;Hong, Mee-Suk;Chung, Joo-Ho;Yim, Sung-Vin
    • Molecular & Cellular Toxicology
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    • v.2 no.4
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    • pp.257-261
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    • 2006
  • Signal transducer and activator of transcription 4 (STAT4) is one of the important mediators in generating inflammation and immune responses. To address the role of Stat4 in carrageenan induced acute inflammation, we performed paw edema measurement and 7.4 k mouse cDNA microarray analysis in carrageenan induced acute inflammation in Stat4 knockout (-/-) mice. Male BALB/c (n=8) and Stat4 -/- (n=5) were used and paw edema was induced with injection of $30\;{\mu}L$ of 1% carrageenan into plantar surface of right hind paw. Next, we isolated the mRNA in mouse whole brain and analyzed cDNA microarray profiles for the changes of the brain expression in Stat4 -/- mice. Interestingly, the increase in paw volume of Stat4 -/- mice was reduced by about 30% as compared to that of wild type. The cDNA microarray analysis revealed the altered expressions of several cytokines (Tnf, Il6, and Il4) and pain-associated proteins (Ptgs2, Gabra6, and Gabbr1) in Stat4 -/- mice. Our results suggest that Stat4 may be related to the inhibitory responses on carrageenan induced acute inflammation.

Bevacizumab Regulates Cancer Cell Migration by Activation of STAT3

  • Wu, Huan-Huan;Zhang, Shuai;Bian, Huan;Li, Xiao-Xu;Wang, Lin;Pu, Yin-Fei;Wang, Yi-Xiang;Guo, Chuan-Bin
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6501-6506
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    • 2015
  • There are numerous clinical cases indicating that long-term use of bevacizumab may increase the invasiveness of tumors. However, to date, little is known about underlying molecular mechanisms. Therefore, the purpose of our study was to investigate effects of bevacizumab in four cancer cells lines (WSU-HN6, CAL27, Tca83, and HeLa). It was found to promote migration and invasion in the WSU-HN6 and Tca83 cases, while exerting inhibitory effects in CAL27 and HeLa cells. The signal transducer and activator of transcription (STAT) 3 inhibitors niclosamide and S3I-201 inhibited the STAT3 signal pathway, which is activated by bevacizumab. These inhibitors also substantially blocked bevacizumab-induced migration of WSU-HN6 and Tca83 cells. Bevacizumab upregulated interleukin (IL)-6 and phosphorylated (p)-STAT3 expression time-dependently. Therefore, we propose that bevacizumab has differential effects on the migration of different cancer cell lines and promotes migration via the IL-6/STAT3 signaling pathway.

Resveratrol Inhibits IL-6-Induced Transcriptional Activity of AR and STAT3 in Human Prostate Cancer LNCaP-FGC Cells

  • Lee, Mee-Hyun;Kundu, Joydeb Kumar;Keum, Young-Sam;Cho, Yong-Yeon;Surh, Young-Joon;Choi, Bu Young
    • Biomolecules & Therapeutics
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    • v.22 no.5
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    • pp.426-430
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    • 2014
  • Prostate cancer is the most frequently diagnosed cancer. Although prostate tumors respond to androgen ablation therapy at an early stage, they often acquire the potential of androgen-independent growth. Elevated transcriptional activity of androgen receptor (AR) and/or signal transducer and activator of transcription-3 (STAT3) contributes to the proliferation of prostate cancer cells. In the present study, we examined the effect of resveratrol, a phytoalexin present in grapes, on the reporter gene activity of AR and STAT3 in human prostate cancer (LNCaP-FGC) cells stimulated with interleukin-6 (IL-6) and/or dihydrotestosterone (DHT). Our study revealed that resveratrol suppressed the growth of LNCaP-FGC cells in a time- and concentration-dependent manner. Whereas the AR transcriptional activity was induced by treatment with either IL-6 or DHT, the STAT3 transcriptional activity was induced only by treatment with IL-6 but not with DHT. Resveratrol significantly attenuated IL-6-induced STAT3 transcriptional activity, and DHT- or IL-6-induced AR transcriptional activity. Treatment of cells with DHT plus IL-6 significantly increased the AR transcriptional activity as compared to DHT or IL-6 treatment alone and resveratrol markedly diminished DHT plus IL-6-induced AR transcriptional activity. Furthermore, the production of prostate-specific antigen (PSA) was decreased by resveratrol in the DHT-, IL-6- or DHT plus IL-6-treated LNCaP-FGC cells. Taken together, the inhibitory effects of resveratrol on IL-6- and/or DHT-induced AR transcriptional activity in LNCaP prostate cancer cells are partly mediated through the suppression of STAT3 reporter gene activity, suggesting that resveratrol may be a promising therapeutic choice for the treatment of prostate cancer.

Effects of Eicosapentaenoic Acid and Docosahexaenoic Acid on Mitochondrial DNA Replication and PGC-1α Gene Expression in C2C12 Muscle Cells

  • Lee, Mak-Soon;Shin, Yoonjin;Moon, Sohee;Kim, Seunghae;Kim, Yangha
    • Preventive Nutrition and Food Science
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    • v.21 no.4
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    • pp.317-322
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    • 2016
  • Mitochondrial biogenesis is a complex process requiring coordinated expression of nuclear and mitochondrial genomes. The peroxisome proliferator-activated receptor gamma co-activator 1-alpha (PGC-$1{\alpha}$) is a key regulator of mitochondrial biogenesis, and it controls mitochondrial DNA (mtDNA) replication within diverse tissues, including muscle tissue. The aim of this study was to investigate the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on mtDNA copy number and PGC-$1{\alpha}$ promoter activity in $C_2C_{12}$ muscle cells. mtDNA copy number and mRNA levels of genes related to mitochondrial biogenesis such as PGC-$1{\alpha}$, nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (Tfam) were assayed by quantitative real-time PCR. The PGC-$1{\alpha}$ promoter from -970 to +412 bp was subcloned into the pGL3-basic vector, which includes a luciferase reporter gene. Both EPA and DHA significantly increased mtDNA copy number, dose and time dependently, and up-regulated mRNA levels of PGC-$1{\alpha}$, NRF1, and Tfam. Furthermore, EPA and DHA stimulated PGC-$1{\alpha}$ promoter activity in a dose-dependent manner. These results suggest that EPA and DHA may modulate mitochondrial biogenesis, which was partially associated with increased mtDNA replication and PGC-$1{\alpha}$ gene expression in $C_2C_{12}$ muscle cells.

Effects of β-Glucan on the Release of Nitric Oxide by Macrophages Stimulated with Lipopolysaccharide

  • Choi, E.Y.;Lee, S.S.;Hyeon, J.Y.;Choe, S.H.;Keum, B.R.;Lim, J.M.;Park, D.C.;Choi, I.S.;Cho, K.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.11
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    • pp.1664-1674
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    • 2016
  • This research analyzed the effect of ${\beta}$-glucan that is expected to alleviate the production of the inflammatory mediator in macrophagocytes, which are processed by the lipopolysaccharide (LPS) of Escherichia. The incubated layer was used for a nitric oxide (NO) analysis. The DNA-binding activation of the small unit of nuclear factor-${\kappa}B$ was measured using the enzyme-linked immunosorbent assay-based kit. In the RAW264.7 cells that were vitalized by Escherichia coli (E. coli) LPS, the ${\beta}$-glucan inhibited both the combatant and rendering phases of the inducible NO synthase (iNOS)-derived NO. ${\beta}$-Glucan increased the expression of the heme oxygenase-1 (HO-1) in the cells that were stimulated by E. coli LPS, and the HO-1 activation was inhibited by the tin protoporphyrin IX (SnPP). This shows that the NO production induced by LPS is related to the inhibition effect of ${\beta}$-glucan. The phosphorylation of c-Jun N-terminal kinases (JNK) and the p38 induced by the LPS were not influenced by the ${\beta}$-glucan, and the inhibitory ${\kappa}B-{\alpha}$ ($I{\kappa}B-{\alpha}$) decomposition was not influenced either. Instead, ${\beta}$-glucan remarkably inhibited the phosphorylation of the signal transducer and activator of transcription-1 (STAT1) that was induced by the E. coli LPS. Overall, the ${\beta}$-glucan inhibited the production of NO in macrophagocytes that was vitalized by the E. coli LPS through the HO-1 induction and the STAT1 pathways inhibition in this research. As the host immune response control by ${\beta}$-glucan weakens the progress of the inflammatory disease, ${\beta}$-glucan can be used as an effective immunomodulator.

A Functional SNP in the MDM2 Promoter Mediates E2F1 Affinity to Modulate Cyclin D1 Expression in Tumor Cell Proliferation

  • Yang, Zhen-Hai;Zhou, Chun-Lin;Zhu, Hong;Li, Jiu-Hong;He, Chun-Di
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.8
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    • pp.3817-3823
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    • 2014
  • Background: The MDM2 oncogene, a negative regulator of p53, has a functional polymorphism in the promoter region (SNP309) that is associated with multiple kinds of cancers including non-melanoma skin cancer. SNP309 has been shown to associate with accelerated tumor formation by increasing the affinity of the transcriptional activator Sp1. It remains unknown whether there are other factors involved in the regulation of MDM2 transcription through a trans-regulatory mechanism. Methods: In this study, SNP309 was verified to be associated with overexpression of MDM2 in tumor cells. Bioinformatics predicts that the T to G substitution at SNP309 generates a stronger E2F1 binding site, which was confirmed by ChIP and luciferase assays. Results: E2F1 knockdown downregulates the expression of MDM2, which confirms that E2F1 is a functional upstream regulator. Furthermore, tumor cells with the GG genotype exhibited a higher proliferation rate than TT, correlating with cyclin D1 expression. E2F1 depletion significantly inhibits the proliferation capacity and downregulates cyclin D1 expression, especially in GG genotype skin fibroblasts. Notably, E2F1 siRNA effects could be rescued by cyclin D1 overexpression. Conclusion: Taken together, a novel modulator E2F1 was identified as regulating MDM2 expression dependent on SNP309 and further mediates cyclin D1 expression and tumor cell proliferation. E2F1 might act as an important factor for SNP309 serving as a rate-limiting event in carcinogenesis.

Effects of Saturated Long-chain Fatty Acid on mRNA Expression of Genes Associated with Milk Fat and Protein Biosynthesis in Bovine Mammary Epithelial Cells

  • Qi, Lizhi;Yan, Sumei;Sheng, Ran;Zhao, Yanli;Guo, Xiaoyu
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.3
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    • pp.414-421
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    • 2014
  • This study was conducted to determine the effects of saturated long-chain fatty acids (LCFA) on cell proliferation and triacylglycerol (TAG) content, as well as mRNA expression of ${\alpha}s1$-casein (CSN1S1) and genes associated with lipid and protein synthesis in bovine mammary epithelial cells (BMECs). Primary cells were isolated from the mammary glands of Holstein dairy cows, and were passaged twice. Then cells were cultured with different levels of palmitate or stearate (0, 200, 300, 400, 500, and 600 ${\mu}M$) for 48 h and fetal bovine serum in the culture solution was replaced with fatty acid-free BSA (1 g/L). The results showed that cell proliferation tended to be increased quadratically with increasing addition of stearate. Treatments with palmitate or stearate induced an increase in TAG contents at 0 to 600 ${\mu}M$ in a concentration-dependent manner, and the addition of 600 ${\mu}M$ was less effective in improving TAG accumulation. The expression of acetyl-coenzyme A carboxylase alpha, fatty acid synthase and fatty acid-binding protein 3 was inhibited when palmitate or stearate were added in culture medium, whereas cluster of differentiation 36 and CSN1S1 mRNA abundance was increased in a concentration-dependent manner. The mRNA expressions of peroxisome proliferator-activated receptor gamma, mammalian target of rapamycin and signal transducer and activator of transcription 5 with palmitate or stearate had no significant differences relative to the control. These results implied that certain concentrations of saturated LCFA could stimulate cell proliferation and the accumulation of TAG, whereas a reduction may occur with the addition of an overdose of saturated LCFA. Saturated LCFA could up-regulate CSN1S1 mRNA abundance, but further studies are necessary to elucidate the mechanism for regulating milk fat and protein synthesis.

The Dose Dependent Effects of Ruxolitinib on the Invasion and Tumorigenesis in Gliomas Cells via Inhibition of Interferon Gamma-Depended JAK/STAT Signaling Pathway

  • Delen, Emre;Doganlar, Oguzhan
    • Journal of Korean Neurosurgical Society
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    • v.63 no.4
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    • pp.444-454
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    • 2020
  • Objective : Glioblastoma multiforme (GBM) is the most aggressive for of brain tumor and treatment often fails due to the invasion of tumor cells into neighboring healthy brain tissues. Activation of the Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway is essential for normal cellular function including angiogenesis, and has been proposed to have a pivotal role in glioma invasion. This study aimed to determine the dose-dependent effects of ruxolitinib, an inhibitor of JAK, on the interferon (IFN)-I/IFN-α/IFN-β receptor/STAT and IFN-γ/IFN-γ receptor/STAT1 axes of the IFN-receptor-dependent JAK/STAT signaling pathway in glioblastoma invasion and tumorigenesis in U87 glioblastoma tumor spheroids. Methods : We administered three different doses of ruxolitinib (50, 100, and 200 nM) to human U87 glioblastoma spheroids and analyzed the gene expression profiles of IFNs receptors from the JAK/STAT pathway. To evaluate activation of this pathway, we quantified the phosphorylation of JAK and STAT proteins using Western blotting. Results : Quantitative real-time polymerase chain reaction analysis demonstrated that ruxolitinib led to upregulated of the IFN-α and IFN-γ while no change on the hypoxia-inducible factor-1α and vascular endothelial growth factor expression levels. Additionally, we showed that ruxolitinib inhibited phosphorylation of JAK/STAT proteins. The inhibition of IFNs dependent JAK/STAT signaling by ruxolitinib leads to decreases of the U87 cells invasiveness and tumorigenesis. We demonstrate that ruxolitinib may inhibit glioma invasion and tumorigenesis through inhibition of the IFN-induced JAK/STAT signaling pathway. Conclusion : Collectively, our results revealed that ruxolitinib may have therapeutic potential in glioblastomas, possibly by JAK/STAT signaling triggered by IFN-α and IFN-γ.

Anti-inflammatory effects of proanthocyanidin-rich red rice extract via suppression of MAPK, AP-1 and NF-κB pathways in Raw 264.7 macrophages

  • Limtrakul, Pornngarm;Yodkeeree, Supachai;Pitchakarn, Pornsiri;Punfa, Wanisa
    • Nutrition Research and Practice
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    • v.10 no.3
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    • pp.251-258
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    • 2016
  • BACKGROUND/OBJECTIVES: Several pharmacological properties of red rice extract have been reported including anti-oxidant, anti-tumor, and reduced cancer cell invasion. This study was conducted to evaluate the anti-inflammatory effects of red rice extract on the production of inflammatory mediators in lipopolysaccharide (LPS)-induced Raw 264.7 macrophages. MATERIALS/METHODS: Pro-inflammatory cytokines including tumor necrosis factor-${\alpha}$ and interleukin-6 were determined by ELISA and cyclooxygenase-2 and inducible nitric oxide synthase expression was evaluated using western blot analysis. In addition, the signaling pathway controlling the inflammatory cascade such as nuclear factor kappa B ($NF-{\kappa}B$), activator proteins-1 (AP-1), and mitogen-activated protein kinase (MAPK) was determined. RESULTS: Our results showed that red rice polar extract fraction (RR-P), but not non-polar extract fraction, inhibited interleukin-6, tumor necrosis factor-${\alpha}$, and nitric oxide production in LPS-induced Raw 264.7 cells. RR-P also reduced the expression of inflammatory enzymes, inducible nitric oxide synthase, and cyclooxygenase-2. In addition, activation of AP-1 and $NF-{\kappa}B$ transcription factor in the nucleus was abrogated by RR-P. RR-P inhibited the phosphorylation of extracellular signaling-regulated kinase 1/2, c-Jun NH2-terminal kinase, and p38 MAPK signaling responsible for the expression of inflammatory mediators in LPS-stimulated Raw 264.7 cells. Based on chemical analysis, high amounts of proanthocyanidin and catechins were detected in the RR-P fraction. However, only proanthocyanidin reduced $NF-{\kappa}B$ and AP-1 activation in LPS-activated Raw 264.7 cells. CONCLUSION: These observations suggest that the anti-inflammatory properties of RR-P may stem from the inhibition of pro-inflammatory mediators via suppression of the AP-1, $NF-{\kappa}B$, and MAPKs pathways.