• Title/Summary/Keyword: Transcription inhibition

검색결과 574건 처리시간 0.286초

Matrix metalloproteinase-13 downregulation and potential cartilage protective action of the Korean Red Ginseng preparation

  • Lee, Je Hyeong;Shehzad, Omer;Ko, Sung Kwon;Kim, Yeong Shik;Kim, Hyun Pyo
    • Journal of Ginseng Research
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    • 제39권1호
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    • pp.54-60
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    • 2015
  • Background: The present study was designed to prepare and find the optimum active preparation or fraction from Korea Red Ginseng inhibiting matrix metalloproteinase-13 (MMP-13) expression, because MMP-13 is a pivotal enzyme to degrade the collagen matrix of the joint cartilage. Methods: From total red ginseng ethanol extract, n-BuOH fraction (total ginsenoside-enriched fraction), ginsenoside diol-type-enriched fraction (GDF), and ginsenoside triol-type-enriched fraction (GTF) were prepared, and ginsenoside diol type-/F4-enriched fraction (GDF/F4) was obtained from Panax ginseng leaf extract. Results: The n-BuOH fraction, GDF, and GDF/F4 clearly inhibited MMP-13 expression compared to interleukin-$1{\beta}$-treated SW1353 cells (human chondrosarcoma), whereas the total extract and ginsenoside diol-type-enriched fraction did not. In particular, GDF/F4, the most effective inhibitor, blocked the activation of p38 mitogen-activated protein kinase (p38 MAPK), c-Jun-activated protein kinase (JNK), and signal transducer and activator of transcription-1/2 (STAT-1/2) among the signal transcription pathways involved. Further, GDF/F4 also inhibited the glycosaminoglycan release from interleukin-$1{\alpha}$-treated rabbit cartilage culture (30.6% inhibition at $30{\mu}g/mL$). Conclusion: Some preparations from Korean Red Ginseng and ginseng leaves, particularly GDF/F4, may possess the protective activity against cartilage degradation in joint disorders, and may have potential as new therapeutic agents.

Phosphoinositide 3-kinase regulates myogenin expression at both the transcriptional and post-transcriptional level during myogenesis

  • Woo, Joo-Hong;Kim, Min-Jeong;Kim, Hye-Sun
    • Animal cells and systems
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    • 제14권3호
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    • pp.147-154
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    • 2010
  • It is well-established that phosphoinositide 3-kinase (PI3-kinase) regulates myogenesis by inducing transcription of myogenin, a key muscle regulatory factor, at the initiation of myoblast differentiation. In this study, we investigated the role of PI3-kinase in cells that have committed to differentiation. PI3-kinase activity increases during myogenesis, and this increase is sustained during the myogenic process; however, its function after the induction of differentiation has not been investigated. We show that LY294002, a PI3-kinase inhibitor, blocked myoblast fusion even after myogenin expression initially increased. In contrast to the inhibitory effects of LY294002 on myogenin mRNA levels during the initiation of differentiation, LY294002 blocked the accumulation of myogenin protein without affecting its mRNA level after differentiation was induced. Treatment with cycloheximide, a translation inhibitor, or actinomycin D, a transcription inhibitor, indicated that the stability of myogenin protein is lower than that of its mRNA. LY294002 inhibited the activities of several important translation factors, including eukaryotic elongation factor-2(eEF2), by altering their phosphorylation status. In addition, LY294002 blocked the incorporation of [$^{35}S$]methionine into newly synthesized proteins. Since myogenin has a relatively short half-life, LY294002-mediated inhibition of post-transcriptional processes resulted in a rapid depletion of myogenin protein. In summary, these results suggest that PI3-kinase plays an important role in regulating the expression of myogenin through post-transcriptional mechanisms after differentiation has been induced.

Molecular Cloning, Protein Expression, and Regulatory Mechanisms of the Chitinase Gene from Spodoptera littoralis Nucleopolyhedrovirus

  • Yasser, Norhan;Salem, Reda;Alkhazindar, Maha;Abdelhamid, Ismail A.;Ghozlan, Said A.S.;Elmenofy, Wael
    • Microbiology and Biotechnology Letters
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    • 제49권3호
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    • pp.305-315
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    • 2021
  • The cotton leafworm, Spodoptera littoralis, is a major pest in Egypt and many countries worldwide, and causes heavy economic losses. As a result, management measures to control the spread of the worm are required. S. littoralis nucleopolyhedrovirus (SpliNPV) is one of the most promising bioagents for the efficient control of insect pests. In this study, a chitinase gene (chitA) of a 1.8 kb DNA fragment was cloned and fully characterized from SpliNPV-EG1, an Egyptian isolate. A sequence of 601 amino acids was deduced when the gene was completely sequenced with a predicted molecular mass of 67 kDa for the preprotein. Transcriptional analyses using reverse transcription polymerase chain reaction (RT-PCR) revealed that chitA transcripts were detected first at 12 h post infection (hpi) and remained detectable until 168 hpi, suggesting their transcriptional regulation from a putative late promoter motif. In addition, quantitative analysis using quantitative RT-PCR showed a steady increase of 7.86-fold at 12 hpi in chitA transcription levels, which increased up to 71.4-fold at 120 hpi. An approximately 50 kDa protein fragment with chitinolytic activity was purified from ChitA-induced bacterial culture and detected by western blotting with an anti-recombinant SpliNPV chitinase antibody. Moreover, purification of the expressed ChitA recombinant protein showed in vitro growth inhibition of two different fungi species, Fusarium solani and F. oxysporum, confirming that the enzyme assembly and activity was correct. The results supported the potential role and application of the SpliNPV-ChitA protein as a synergistic agent in agricultural fungal and pest control programs.

Inhibitory effects of crude polysaccharide fractions from Annona muricata L. on melanogenesis (그라비올라 잎(Annona muricata L.) 조다당 분획분의 멜라닌 생성 저해 효과)

  • Kim, Yi-Eun;Byun, Eui-Hong
    • Korean Journal of Food Science and Technology
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    • 제51권1호
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    • pp.52-57
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    • 2019
  • The objective of this study was to evaluate the anti-melanogenic effects of crude polysaccharide fractions from Annona muricata L. (ALP) in 3-isobutyl-1-methylxanthine (IBMX) stimulating hormone-induced mouse B16F10 melanoma cells. The inhibitory effect of ALP on tyrosinase activity was approximately $33.88{\pm}0.79%$ at 5 mg/mL. Additionally, the B16F10 cellular tyrosinase and melanin synthesis inhibition activities by ALP were $54.21{\pm}4.76$ and $56.74{\pm}6.97%$ at $250{\mu}g/mL$, respectively. Similarly, whitening-related protein tyrosinase, tyrosinase-related protein 1 (TRP-1) and TRP-2, and microphthalmia-associated transcription factor (MITF) were reduced by ALP treatment. These results indicated that ALP could be used as a functional cosmetic ingredient after confirming its whitening activity related to melanin content.

Screening of Stat3 inhibitory effects of Korean herbal medicines in the A549 human lung cancer cell line

  • Park, Jong-Shik;Bang, Ok-Sun;Kim, Jinhee
    • Integrative Medicine Research
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    • 제3권2호
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    • pp.67-73
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    • 2014
  • Background: The transcription factor signal transducer and activator of transcription 3 (Stat3)is constitutively activated in many human cancers. It promotes tumor cell proliferation,inhibits apoptosis, induces angiogenesis and metastasis, and suppresses antitumor hostimmune responses. Therefore, Stat3 has emerged as a promising molecular target for cancertherapies. In this study, we evaluated the Stat3-suppressive activity of 38 herbal medicinestraditionally used in Korea.Methods: Medicinal herb extracts in 70% ethanol were screened for their ability to suppressStat3 in the A549 human lung cancer cell line. A Stat3-responsive reporter assay system wasused to detect intracellular Stat3 activity in extract-treated cells, and Western blot analyseswere performed to measure the expression profiles of Stat3-regulated proteins.Results: Fifty percent of the 38 extracts possessed at least mild Stat3-suppressive activities(i.e., activity less than 75% of the vehicle control). Ethanol extracts of Bupleurum falcatumL., Taraxacum officinale Weber, Solanum nigrum L., Ulmus macrocarpa Hance, Euonymus alatusSieb., Artemisia capillaris Thunb., and Saururus chinensis (Lour.) Baill inhibited up to 75% of thevehicle control Stat3 activity level. A549 cells treated with these extracts also had reducedBcl-xL, Survivin, c-Myc, and Mcl-1 expression.Conclusion: Many medicinal herbs traditionally used in Korea contain Stat3 activity-suppressing substances. Because of the therapeutic impact of Stat3 inhibition, these resultscould be useful when developing novel cancer therapeutics from medicinal herbs.

Transcriptional Regulatory Role of NELL2 in Preproenkephalin Gene Expression

  • Ha, Chang Man;Kim, Dong Hee;Lee, Tae Hwan;Kim, Han Rae;Choi, Jungil;Kim, Yoonju;Kang, Dasol;Park, Jeong Woo;Ojeda, Sergio R.;Jeong, Jin Kwon;Lee, Byung Ju
    • Molecules and Cells
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    • 제45권8호
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    • pp.537-549
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    • 2022
  • Preproenkephalin (PPE) is a precursor molecule for multiple endogenous opioid peptides Leu-enkephalin (ENK) and Met-ENK, which are involved in a wide variety of modulatory functions in the nervous system. Despite the functional importance of ENK in the brain, the effect of brain-derived factor(s) on PPE expression is unknown. We report the dual effect of neural epidermal growth factor (EGF)-like-like 2 (NELL2) on PPE gene expression. In cultured NIH3T3 cells, transfection of NELL2 expression vectors induced an inhibition of PPE transcription intracellularly, in parallel with downregulation of protein kinase C signaling pathways and extracellular signal-regulated kinase. Interestingly, these phenomena were reversed when synthetic NELL2 was administered extracellularly. The in vivo disruption of NELL2 synthesis resulted in an increase in PPE mRNA level in the rat brain, suggesting that the inhibitory action of intracellular NELL2 predominates the activation effect of extracellular NELL2 on PPE gene expression in the brain. Biochemical and molecular studies with mutant NELL2 structures further demonstrated the critical role of EGF-like repeat domains in NELL2 for regulation of PPE transcription. These are the first results to reveal the spatio-specific role of NELL2 in the homeostatic regulation of PPE gene expression.

AURKB, in concert with REST, acts as an oxygen-sensitive epigenetic regulator of the hypoxic induction of MDM2

  • Kim, Iljin;Choi, Sanga;Yoo, Seongkyeong;Lee, Mingyu;Park, Jong-Wan
    • BMB Reports
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    • 제55권6호
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    • pp.287-292
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    • 2022
  • The acute response to hypoxia is mainly driven by hypoxia-inducible factors, but their effects gradually subside with time. Hypoxia-specific histone modifications may be important for the stable maintenance of long-term adaptation to hypoxia. However, little is known about the molecular mechanisms underlying the dynamic alterations of histones under hypoxic conditions. We found that the phosphorylation of histone H3 at Ser-10 (H3S10) was noticeably attenuated after hypoxic challenge, which was mediated by the inhibition of aurora kinase B (AURKB). To understand the role of AURKB in epigenetic regulation, DNA microarray and transcription factor binding site analyses combined with proteomics analysis were performed. Under normoxia, phosphorylated AURKB, in concert with the repressor element-1 silencing transcription factor (REST), phosphorylates H3S10, which allows the AURKB-REST complex to access the MDM2 proto-oncogene. REST then acts as a transcriptional repressor of MDM2 and downregulates its expression. Under hypoxia, AURKB is dephosphorylated and the AURKB-REST complex fails to access MDM2, leading to the upregulation of its expression. In this study, we present a case of hypoxia-specific epigenetic regulation of the oxygen-sensitive AURKB signaling pathway. To better understand the cellular adaptation to hypoxia, it is worthwhile to further investigate the epigenetic regulation of genes under hypoxic conditions.

Identification of a Novel Human Zinc Finger Gene, ZNF438, with Transcription Inhibition Activity

  • Zhong, Zhaomin;Wan, Bo;Qiu, Yun;Ni, Jun;Tang, Wenwen;Chen, Xinya;Yang, Yun;Shen, Suqin;Wang, Ying;Bai, Meirong;Lang, Qingyu;Yu, Long
    • BMB Reports
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    • 제40권4호
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    • pp.517-524
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    • 2007
  • There were many different families of zinc finger proteins that contained multiple cysteine and/or histidine residues and used zinc to stabilize their folds. The classical C2H2 zinc finger proteins were the founding members of this superfamily and were among the most abundant proteins in eukaryotic genomes. C2H2 proteins typically contained several C2H2 fingers that made tandem contacts along the DNA. Here we reported a novel C2H2 type zinc finger gene, ZNF438, which encoded 828 amino acids that formed five zinc finger domains. Bioinformatics analysis revealed that the ZNF438 was mapped to human chromosome 10p11.2 and shared 62% identity with rat and mouse homologues. RT-PCR analysis indicated that it was ubiquitously expressed in 18 human adult tissues. With immunofluorescence assay, it was shown that the exogenous Flag-tagged ZNF438 was located in nucleus of COS-7 cells. To further explore the function of ZNF438, we examined the transcriptional activity of ZNF438 protein by transfecting recombinant pM-ZNF438 into mammalian cells. The subsequent analysis based on the duel luciferase assay system showed that ZNF438 was a transcriptional repressor.

Anti-obese Effects and Signaling Mechanisms of Chaenomeles sinensis extracts in 3T3-L1 Preadipocytes and Obese Mice Fed a High-fat Diet (3T3L-1 지방전구세포와 고지방식이로 유도된 비만 마우스 모델에서 모과 추출물의 항비만 효과와 억제 기전)

  • Kim, Da-Hye;Kwon, Bora;Kim, Sang Jun;Kim, HongJun;Jeong, Seung-Il;Yu, Kang-Yeol;Kim, Seon-Young
    • Herbal Formula Science
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    • 제25권4호
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    • pp.457-469
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    • 2017
  • Obesity is one of the most serious health problem because it induced numerous metabolic syndrome and increases the incidence of various disease, including diabetes, hypertension, dyslipidemia, atherosclerosis, and cancer. In 3T3-L1 adipocytes, increases in reactive oxygens species (ROS) occur with lipid accumulation. NADPH oxidase, producing superoxide anion, may contribute to the development of obesity-associated insulin resistance and type 2 diabetes. In this study, we elucidated the effect of Chaenomeles sinensis koehne extract (CSE) against the development of obesity and the inhibition mechanisms in 3T3-L1 preadiocytes. CSE decreased triglyceride content and inhibited the expression of adipogenic transcription factors including peroxisome proliferator-activated receptor $(PPAR){\gamma}$, CCAT/enhancer binding protein $(C/EBP){\alpha}$ and sterol regulatory element-binding protein (SREBP-1). In addition, CSE highly increased antioxidant activity in a dose-dependent manner. CSE remarkably reduced intracellular ROS increase and NAD(P)H oxidase activity, NOX1, NOX4, Rac1 protein expression, and phosphorylation of p47phox and p67phox We also studied the effect of CSE on weight gain induced by high-fat diet. The oral treatment of CSE (500 mg/kg, body weight) in diet-induced obese (DIO) mice showed decrease in triglyceride and adipocyte size. Therefore, these results indicate that the effect of CSE on anti-obese effects, adipocyte differentiation and reducing triglyceride contents as well as adipocyte size in obese mice, may be associated with inhibition of NAD(P)H oxidase-induced ROS production and adipose transcription factors. These results showed the potential to inhibit the obesity by CSE treatment through controlling the activation of NAD(P)H oxidase in vitro and in vivo obese model.

Experimental Study on Inhibition Effects of the XAF1 Gene against Lung Cancer Cell Proliferation

  • Yang, Wen-Tao;Chen, Dong-Lai;Zhang, Fu-Quan;Xia, Ying-Chen;Zhu, Rong-Ying;Zhou, Duan-Shan;Chen, Yong-Bing
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권18호
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    • pp.7825-7829
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    • 2014
  • Objective: To investigate the effect of high expression of XAF1 in vivo or in vitro on lung cancer cell growth and apoptosis. Methods: 1. The A549 human lung cancer cell line was transfected with Ad5/F35 - XAF1, or Ad5/F35 - Null at the same multiplicity of infection (MOI); (hereinafter referred to as transient transfected cell strain); XAF1 gene mRNA and protein expression was detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting respectively. 2. Methyl thiazolyl tetrazolium (MTT) and annexin V-FITC/PI double staining were used to detect cell proliferation and apoptosis before and after infection of Ad5/F35 - XAF1 with Western blotting for apoptosis related proteins, caspase 3, caspase - 8 and PARP. 3. After the XAF1 gene was transfected into lung cancer A549 cells by lentiviral vectors, and selected by screening with Blasticidin, reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were applied to detect mRNA and protein expression, to establish a line with a stable high expression of XAF1 (hereinafter referred to as stable expression cell strain). Twenty nude mice were randomly divided into groups A and B, 10 in each group: A549/XAF1 stable expression cell strain was subcutaneously injected in group A, and A549/Ctrl stable cell line stable expression cell strain in group B (control group), to observe transplanted tumor growth in nude mice. Results: The mRNA and protein expression of XAF1 in A549 cells transfected by Ad5/F35 - XAF1 was significantly higher than in the control group. XAF1 mediated by adenovirus vector demonstrated a dose dependent inhibition of lung cancer cell proliferation and induction of apoptosis. This was accompanied by cleavage of caspase -3, -8, -9 and PARP, suggesting activation of intrinsic or extrinsic apoptotic pathways. A cell strain of lung cancer highly expressing XAF1 was established, and this demonstrated delayed tumor growth after transplantation in vivo. Conclusion: Adenovirus mediated XAF1 gene expression could inhibit proliferation and induce apoptosis in lung cancer cells in vitro; highly stable expression of XAF1 could also significantly inhibit the growth of transplanted tumors in nude mouse, with no obvious adverse reactions observed. Therefore, the XAF1 gene could become a new target for lung cancer treatment.