• Title/Summary/Keyword: Reporter gene assay

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Hypoxia Inducible Factor-$1{\alpha}$ Directly Induces the Expression of Receptor Activator of Nuclear Factor-${\kappa}B$ Ligand in MLO-Y4 Osteocytes

  • Baek, Kyunghwa;Park, Hyun-Jung;Baek, Jeong-Hwa
    • International Journal of Oral Biology
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    • v.40 no.1
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    • pp.19-25
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    • 2015
  • Osteocytes may function as mechanotransducers by regulating local osteoclastogenesis. Reduced availability of oxygen, i.e. hypoxia, could occur during disuse, bone development, and fracture. Receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL) is an osteoblast/stromal cell derived essential factor for osteoclastogenesis. The hypoxia induced osteoclastogenesis via increased RANKL expression in osteoblasts was demonstrated. Hypoxic regulation of gene expression generally involves activation of the hypoxia-inducible factor (HIF) transcription pathway. In the present study, we investigated whether hypoxia regulates RANKL expression in murine osteocytes and HIF-$1{\alpha}$ mediates hypoxia-induced RANKL expression by transactivating RANKL promoter, to elucidate the role of osteocyte in osteoclastogenesis in the context of hypoxic condition. The expression levels of RANKL mRNA and protein, as well as hypoxia inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) protein, were significantly increased in hypoxic condition in MLO-Y4s. Constitutively active HIF-$1{\alpha}$ alone significantly increased the levels of RANKL expression in MLO-Y4s under normoxic conditions, whereas dominant negative HIF-$1{\alpha}$ blocked hypoxia-induced RANKL expression. To further explore to find if HIF-$1{\alpha}$ directly regulates RANKL transcription, a luciferase reporter assay was conducted. Hypoxia significantly increased RANKL promoter activity, whereas mutations of putative HIF-$1{\alpha}$ binding elements in RANKL promoter prevented this hypoxia-induced RANKL promoter activity in MLO-Y4s. These results suggest that HIF-$1{\alpha}$ mediates hypoxia-induced up-regulation of RANKL expression, and that in osteocytes of mechanically unloaded bone, hypoxia enhances osteoclastogenesis, at least in part, via an increased RANKL expression in osteocytes.

The Inhibitory Effect on Androgen Receptor-Dependent Prostate Cancer Cell Growth by Anti-Histone Acetyltransferase Activity from Terminalia chebula Retz. Fruit Methanol Extract (가자(Terminalia chebula Retz.) 열매 메탄올 추출물의 Histone Acetyltransferase 활성 저해에 따른 항전립선암 효과)

  • Lee, Yoo-Hyun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.10
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    • pp.1539-1543
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    • 2013
  • The inhibitory effect of histone acetyltransferase from methanol extract of Terminalia chebula Retz. fruit (TCME) was investigated in prostate cancer cell. TCME significantly inhibited histone acetyltransferase (HAT) activity by over 50% at 100 ${\mu}g/mL$ concentration. TCME treatment repressed androgen receptor (AR) mediated transcription, mRNA level of AR target genes, prostate specific antigen (PSA) and NKX-3.1, as well as AR acetylation. Finally, the prostate cancer cell viability was dramatically reduced by TCME treatment at 0~100 ${\mu}g/mL$ concentration. These results indicated that TCME, as a potent HAT inhibitor, could suppress prostate cancer cell growth by AR mediated transcription regulation.

Post-Transcriptional Control of Tropoelastin in Aortic Smooth Muscle Cells Affects Aortic Dissection Onset

  • Qi, You-Fei;Shu, Chang;Xiao, Zhan-Xiang;Luo, Ming-Yao;Fang, Kun;Guo, Yuan-Yuan;Zhang, Wen-Bo;Yue, Jie
    • Molecules and Cells
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    • v.41 no.3
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    • pp.198-206
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    • 2018
  • Aortic dissection (AD) is a catastrophic disease with high mortality and morbidity, characterized with fragmentation of elastin and loss of smooth muscle cells. Although AD has been largely attributable to polymorphisms defect in the elastin-coding gene, tropoelastin (TE), other undermined factors also appear to play roles in AD onset. Here, we investigated the effects of post-transcriptional control of TE by microRNAs (miRNAs) on elastin levels in aortic smooth muscle cells (ASMC). We found that miR-144-3p is a miRNA that targets TE mRNA in both human and mouse. Bioinformatics analyses and dual luciferase reporter assay showed that miR-144-3p inhibited protein translation of TE, through binding to the 3'-UTR of the TE mRNA. Interestingly, higher miR-144-3p levels and lower TE were detected in the ASMC obtained from AD patients, compared to those from non-AD controls. In a mouse model for human AD, infusion of adeno-associated viruses (serotype 6) carrying antisense for miR-144-3p (asmiR-144-3p) under CAG promoter significantly reduced the incidence and severity of AD, seemingly through enhancement of TE levels in ASMC. Thus, our data suggest an essential role of miR-144-3p on the pathogenesis of AD.

Mechanism of Action of Nigella sativa on Human Colon Cancer Cells: the Suppression of AP-1 and NF-κB Transcription Factors and the Induction of Cytoprotective Genes

  • Elkady, Ayman I;Hussein, Rania A;El-Assouli, Sufian M
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.17
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    • pp.7943-7957
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    • 2015
  • Background and Aims: Colorectal cancer is one of the leading causes of death in the world. The aim of this study was to investigate the growth-suppression potentiality of a crude saponin extract (CSENS) prepared from medicinal herb, Nigella sativa, on human colon cancer cells, HCT116. Materials and Methods: HCT116 cells were subjected to increasing doses of CSENS for 24, 48 and 72 h, and then harvested and assayed for cell viability by WST-1. Flow cytometry analyses, cell death detection ELISA, fluorescent stains (Hoechst 33342 and acridine orange/ethidium bromide), DNA laddering and comet assays were carried out to confirm the apoptogenic effects of CSENS. Luciferase reporter gene assays, quantitative reverse transcription-polymerase chain reaction and Western blot analyses were performed to assess the impact of CAERS and CFEZO on the expression levels of key regulatory proteins in HCT116 cells. Results: The results demonstrated that CSENS inhibited proliferation and induced apoptosis. Apoptosis was confirmed by flow cytometry analyses, while CSENS-treated cells exhibited morphological hallmarks of apoptosis including cell shrinkage, irregularity in cellular shape, cellular detachment and chromatin condensation. Biochemical signs of apoptosis, such as DNA degradation, were observed by comet assay and gel electrophoresis. The pro-apoptotic effect of CSENS was caspase-3-independent and associated with increase of the Bax/Bcl-2 ratio. CSENS treatment down-regulated transcriptional and DNA-binding activities of NF-${\kappa}B$ and AP-1 proteins, associated with down-regulation of their target oncogenes, c-Myc, cyclin D1 and survivin. On the other hand, CSENS up-regulated transcriptional and DNA-binding activities of Nrf2 and expression of cytoprotective genes. In addition, CSENS modulated the expression levels of ERK1/2 MAPK, p53 and p21. Conclusions: These findings suggest that CSENS may be a valuable agent for treatment of colon cancer.

The Evaluation of the Effect of Herbal Extract on Osteoarthritis: In Vitro and In Vivo Study

  • Kim, Jaeyong;Yang, Siyoung;Choi, Chul-yung
    • Preventive Nutrition and Food Science
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    • v.21 no.4
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    • pp.310-316
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    • 2016
  • In this study, the anti-osteoarthritis effects of Cynanchum wilfordii, Phlomis umbrosa, and Angelica gigas extract (CPAE), observed and confirmed in previously clinical studies were further investigated by in vitro and in vivo studies. Anabolic biomarkers related to healthy cartilage maintenance, such as aggrecan, type II collagen ${\alpha}$-1 (Col2a1), sex determining region Y-box-9 (Sox-9), and catabolic biomarkers related to osteoarthritis, such as cyclooxygenase-2 (Cox-2), matrix metalloproteinase-13 (Mmp13), and nuclear factor kappa-light-chain-enhancer of activated B cells ($Nf{\kappa}b$), were evaluated by quantitative reverse transcriptase polymerase chain reaction and reporter gene assay. In vitro study results showed significant changes in both anabolic and catabolic biomarkers. For anabolic factors, significant changes in the level of aggrecan (P<0.05), Col2a1 (P<0.05), and Sox-9 (P<0.01) activation were shown after treatment of cartilage cells with CPAE (50 ng/mL) with similar efficacy compared to insulin growth factor, the positive control (100 ng/mL). For catabolic factors, significant changes in the inhibition activity of Cox-2 (P<0.05), Mmp13 (P<0.01), and $Nf{\kappa}b$ (P<0.05) were shown for CPAE (50 ng/mL) with similar efficacy compared to Celecoxib, the positive control ($10{\mu}M$). In the in vivo carrageenan-induced paw edema model study results showed that CPAE-treated groups (100 mg/kg) and Celecoxib-treated groups (60 mg/kg) showed comparably significant efficacy of inhibition by 37.1% and 52.1%, respectively. Furthermore, CPAE (200 mg/kg) showed similar effect to Celecoxib (60 mg/kg) with an inhibition rate of 54.3%. This result confirms that CPAE effectively inhibited the inflammation-induced osteoarthritis symptoms.

miR-140 inhibits porcine fetal fibroblasts proliferation by directly targeting type 1 insulin-like growth factor receptor and indirectly inhibiting type 1 insulin-like growth factor receptor expression via SRY-box 4

  • Geng, Hongwei;Hao, Linlin;Cheng, Yunyun;Wang, Chunli;Wei, Wenzhen;Yang, Rui;Li, Haoyang;Zhang, Ying;Liu, Songcai
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.10
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    • pp.1674-1682
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    • 2020
  • Objective: This study aimed to elucidate the effect of miR-140 on the proliferation of porcine fetal fibroblasts (PFFs) and identify the target genes of miR-140 in PFFs. Methods: In this study, bioinformatics software was used to predict and verify target genes of miR-140. Quantitative polymerase chain reaction and western blot were used to detect the relationship between miR-140 and its target genes in PFFs. Dual luciferase reporter gene assays were performed to assess the interactions among miR-140, type 1 insulin-like growth factor receptor (IGF1R), and SRY-box 4 (SOX4). The effect of miR-140 on the proliferation of PFFs was measured by CCK-8 when PFFs were transfected with a miR-140 mimic or inhibitor. The transcription factor SOX4 binding to promoter of IGF1R was detected by chromatin immunoprecipitation assay (ChIP). Results: miR-140 directly targeted IGF1R and inhibited proliferation of PFFs. Meanwhile, miR-140 targeted transcription factor SOX4 that binds to promoter of porcine IGF1R to indirectly inhibit the expression of IGF1R. In addition, miR-140 inhibitor promoted PFFs proliferation, which is abrogated by SOX4 or IGF1R knockdown. Conclusion: miR-140 inhibited PFFs proliferation by directly targeting IGF1R and indirectly inhibiting IGF1R expression via SOX4, which play an important role in the development of porcine fetal.

Effects of Combined Treatments of Lithium and Valproate on the Phosphorylation of ERK1/2 and Transcriptional Activity of ELK1 and C-FOS in PC12 Cells (리튬 및 발프로에이트 병용 처치가 PC12 세포에서 ERK1/2 인산화와 ELK1 및 C-FOS 전사활성에 미치는 영향)

  • Cha, Seung Keun;Kim, Se Hyun;Ha, Kyooseob;Shin, Soon Young;Kang, Ung Gu
    • Korean Journal of Biological Psychiatry
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    • v.20 no.4
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    • pp.159-165
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    • 2013
  • Objectives Mechanisms of clinical synergistic effects, induced by co-treatments of lithium and valproate, are unclear. Extracellular signal-regulated kinase (ERK) has been suggested to play important roles in mechanisms of the action of mood stabilizers. In this study, effects of co-treatments of lithium and valproate on the ERK1/2 signal pathway and its down-stream transcription factors, ELK1 and C-FOS, were investigated in vitro. Methods PC12 cells, human pheochromocytoma cells, were treated with lithium chloride (30 mM), valproate (1 mM) or lithium chloride + valproate. The phosphorylation of ERK1/2 was analyzed with immunoblot analysis. Transcriptional activities of ELK1 and C-FOS were analyzed with reporter gene assay. Results Single treatment of lithium and valproate increased the phosphorylation of ERK and transcriptional activities of ELK1 and C-FOS, respectively. Combined treatments of lithium and valproate induced more robust increase in the phosphorylation of ERK1/2 and transcriptional activities of ELK1 and C-FOS, compared to those in response to single treatment of lithium or valproate. Conclusions Co-treatments of lithium and valproate induced synergistic increase in the phosphorylation of ERK1/2 and transcriptional activities of its down-stream transcription factors, ELK1 and C-FOS, compared to effects of single treatment. The findings might suggest potentiating effects of lithium and valproate augmentation treatment strategy.

Inhibition of Inducible Nitric Oxide Synthase and Cyclooxygenase-2 by Gamijihwang-tang Via Suppression of Nuclear Factor-B Activation in RAW 264.7 cells

  • Jang Du-Hyun;Kim Ji-Young;Han Eun-Hee;Park Hee-Ok;Kim Dong-Hee;Jeong Hye-Gwang;Yoo Dong-Yeol
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.5
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    • pp.1405-1410
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    • 2005
  • Asthma is recognized today as an inflammatory disease of the lung characterized by acute non-specific airway hypersensitiveness in association with chronic pulmonary inflammation. Gamijihwang-tang(GJT), a fortified prescription of YMJHT, is applied for the treatments of chronic coughing and asthma, and post-delivery coughing and asthma in the gynecology. Also in the clinical practice, GJT is known to be very effective for controlling coughing and asthma as a cold sequoia. In this study, we investigated the effects of GJT on the lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) production, and on the level of inducible nitric oxide synthase (iNOS) and Cyclooxygenase-2 expression in murine macrophage RAW 264.7 cells. We found that GJT inhibited LPS-induced NO and $PGE_2$ production in a dose dependent manner. Furthermore, GJT inhibited the expression of LPS-induced iNOS and COX-2 protein and mRNA expression in RAW 264.7 macrophages. Treatment with GJT of RAW 264.7 cells transfected with a reporter construct indicated a reduced level of LPS-induced nuclear factor-KB (NF-kB) activity and effectively lowered NF-kB binding as measured by transient transfection assay. These results suggest that the main inhibitory mechanism of the GJT may be the reduction of iNOS and COX-2 gene expression through blocking of NF-kB activation.

Role of miR-511 in the Regulation of OATP1B1 Expression by Free Fatty Acid

  • Peng, Jin Fu;Liu, Li;Guo, Cheng Xian;Liu, Shi Kun;Chen, Xiao Ping;Huang, Li Hua;Xiang, Hong;Huang, Zhi Jun;Yuan, Hong;Yang, Guo Ping
    • Biomolecules & Therapeutics
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    • v.23 no.5
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    • pp.400-406
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    • 2015
  • MicroRNAs (miRNAs) are a family of non-coding RNA that are able to adjust the expression of many proteins, including ATP-binding cassette transporter and organic cation transporter. We sought to evaluate the effect of miR-511 on the regulation of OATP1B1 expression by free fatty acids. When using free fatty acids to stimulate Chang liver cells, we found that the expression of miR-511 increased significantly while the expression of OATP1B1 decreased. We also proved that SLCO1B1 is the target gene of miR-511 with a bioinformatics analysis and using the dual luciferase reporter assay. Furthermore, the expressions of SLCO1B1 and OATP1B1 decreased if transfecting Chang liver cells with miR-511, but did not increase when transfecting the inhibitors of miR-511 into steatosis cells. Our study indicates that miR-511 may play an important role in the regulation of OATP1B1 expression by free fatty acids.

Anti-inflammatory Effects of the Methanol Extract of Polytrichum Commune via NF-κB Inactivation in RAW 264.7 Macrophage Cells

  • Cho, Woong;Park, Seung-Jae;Shin, Ji-Sun;Noh, Young-Su;Cho, Eu-Jin;Nam, Jung-Hwan;Lee, Kyung-Tae
    • Biomolecules & Therapeutics
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    • v.16 no.4
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    • pp.385-393
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    • 2008
  • As an attempt to search for bioactive natural products exerting anti-inflammatory activity, we evaluated the effects of the methanol extract of Polytrichum commune Hedw (PCM) (Polytrichaceae) on lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$) and pro-inflammatory cytokines release in murine macrophage cell line RAW 264.7. PCM potently inhibits the production of NO, $PGE_2$, tumor necrosis factor (TNF)-$\alpha$ and interleukin (IL)-6. Consistent with these results, PCM also concentration-dependently inhibited LPS-induced inducible NO synthase (iNOS) and cyclooxygase (COX)-2 at the protein levels, and iNOS, COX-2, TNF-$\alpha$ and IL-6 at the mRNA levels without an appreciable cytotoxic effect on RAW 264.7 macrophag cells. Furthermore, PCM inhibited LPS-induced nuclear factor-kappa B (NF-$\kappa$B) activation as determined by NF-$\kappa$B reporter gene assay, and this inhibition was associated with a decrease in the nuclear translocation of p65 and p50 NF-$\kappa$B. Taken together, these results suggest that PCM may play an anti-inflammatory role in LPS-stimulated RAW 264.7 macrophages through the inhibitory regulation of iNOS, COX-2, TNF-$\alpha$ and IL-6 via NF-$\kappa$B inactivation.