1.Transcriptional activation of nuclear estrogen receptor and progesterone receptor and its regulation.
Qi-Liang XIN ; Jing-Tao QIU ; Sheng CUI ; Guo-Liang XIA ; Hai-Bin WANG
Acta Physiologica Sinica 2016;68(4):435-454
Estrogen receptor (ER) and progesterone receptor (PR) are two important members of steroid receptors family, an evolutionarily conserved family of transcription factors. Upon binding to their ligands, ER and PR enter cell nucleus to interact with specific DNA element in the context of chromatin to initiate the transcription of diverse target genes, which largely depends on the timely recruitment of a wide range of cofactors. Moreover, the interactions between steroid hormones and their respective receptors also trigger post-translational modifications on these receptors to fine-tune their transcriptional activities. Besides the well-known phosphorylation modifications on tyrosine and serine/threonine residues, recent studies have identified several other covalent modifications, such as ubiquitylation and sumoylation. These post-translational modifications of steroid receptors affect its stability, subcellular localization, and/or cofactor recruitment; eventually influence the duration and extent of transcriptional activation. This review is to focus on the recent research progress on the transcriptional activation of nuclear ER and PR as well as their physiological functions in early pregnancy, which may help us to better understand related female reproductive diseases.
Ligands
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Phosphorylation
;
Receptors, Estrogen
;
Receptors, Progesterone
;
Sumoylation
;
Transcriptional Activation
2.Roles of RUNX1 and PU.1 in CCR3 Transcription.
Su Kang KONG ; Byung Soo KIM ; Sae Mi HWANG ; Hyune Hwan LEE ; Il Yup CHUNG
Immune Network 2016;16(3):176-182
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.
Eosinophils
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Mutagenesis
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RNA, Small Interfering
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T-Lymphocytes
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Th2 Cells
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Transcription Factors
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Transcriptional Activation
;
Transfection
3.Chromatin organization and transcriptional activation of Hox genes.
Ji Yeon LEE ; Hyehyun MIN ; Xinnan WANG ; Abdul Aziz KHAN ; Myoung Hee KIM
Anatomy & Cell Biology 2010;43(1):78-85
Spatially and temporally programmed expression of the Hox genes along the antero-posterior (A-P) axis is essential for correct pattern formation during embryonic development. An accumulating body of evidence indicates the pivotal role of spatial chromatin organization for the coordination of gene regulation. Recently, chromosome conformation capture (3C) technique has been developed and opened a new way to study chromosomal interactions in the nucleus. In this study, we describe 3C method we applied in F9 embryonic teratocarcinoma cells and demonstrate that the chromosomal interactions at Hox loci are successfully detected. Interestingly, at Hoxc loci, the abundance of intrachromosomal interactions with neighboring fragments was drastically decreased when the genes are expressed. These results indicate the possibility of the dynamic pattern of chromosomal interaction in association with the transcriptional regulation of Hox genes.
Axis, Cervical Vertebra
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Chromatin
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Embryonic Development
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Female
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Gene Expression
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Genes, Homeobox
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Pregnancy
;
Teratocarcinoma
;
Transcriptional Activation
4.Immunohistochemical Study of GLI-1 Expression in the Basal Cell Carcinoma of Sun-Exposed and Non-Exposed Areas.
Young Ju SEO ; Chul Woo KIM ; Kwang Ho KIM ; Kwang Joong KIM ; Hye Rim PARK ; Yong Sun KIM
Korean Journal of Dermatology 2005;43(2):177-183
BACKGROUND: Basal cell carcinoma (BCC) is the most prevalent cancer in the western world, showing a rapid increase in incidence. Activation of the Sonic hedgehog/Patched (PTCH) and is sisnalling pathway, due to PTCH inactivation, is a key event in sporadic and familial BCC development in humans and is associated with transcriptional activation of specific target genes, including GLI-1. Recently, PTCH inactivation by UV-specific mutation has been reported to develop BCC. OBJECTIVE: To evaluate the expression pattern of GLI-1 oncogene in BCC of sun-exposed and non-exposed areas of skin. METHOD: We examined 20 cases of BCC, and 4 cases of BCC occurring in sun-exposed and non-exposed areas, using an immunohistochemical method with paraffin-embedded sections. RESULTS: The results were as follows. 1. All cases of BCC showed a positive staining for GLI-1 protein. 2. In the staining pattern of GLI-1 protein, BCC in both sun-exposed and non-exposed areas showed diffuse staining throughout the tumor lobules. Moreover, the degree of staining was not found to be different between the BCC of sun-exposed and non-exposed areas. CONCLUSION: These results suggest that increased GLI-1 expression is important for BCC development. And multiple factors, including PTCH mutation due to UV irradiation, may affect GLI-1 expression.
Carcinoma, Basal Cell*
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Humans
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Incidence
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Oncogenes
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Skin
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Transcriptional Activation
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Western World
5.The Effects of Peroxisome Proliferator Activated Receptor alpha (PPARalpha) Activator on Patients with Facial Erythema.
Yeseul KIM ; Youlee JUNG ; Jongkyung YOUM ; Joonhong PARK ; You In BAE ; Younglip PARK ; Sanghoon LEE
Korean Journal of Dermatology 2014;52(9):608-614
BACKGROUND: Long-term use of topical steroids for inflammatory skin diseases can induce complications, and efforts to find a better treatment are being continued. Peroxisome proliferator activated receptor alpha (PPARalpha) suppresses the skin's inflammatory reaction, maintains the homeostasis of the skin, and plays an important role in skin barrier function. OBJECTIVE: This study analyzed the effects of a skin moisturizer containing PPARalpha activator on various inflammatory skin diseases causing facial erythema and evaluated the observed improvements. METHODS: The PPARa activator used for this study is composed of supercritical extracts from Euryale ferox, Euphorbia lathyris, and Rosa multiflora, which showed significant effects in the transactivation assay compared to Wy14643. Moisturizer containing PPARalpha was applied to the faces of 31 patients with symmetric facial erythema, with PPARalpha applied on one-half of the face and a control moisturizer on the other half of the face twice a day for 2 weeks. The percentage of erythema index, erythema index, skin hydration, and transepidermal water loss was checked to evaluate treatment effect. Both patients and clinicians each assessed the improvement of erythema on both sides of a patient's face. RESULTS: Moisturizer containing PPARalpha agonist significantly improved erythema index measured with Mexameter MX18(R) and percentage of erythema index by polarization color imaging system (DermaVision-PRO(R)) (p<0.05). However, there was no significant improvement in skin hydration and transepidermal water loss. Improvement of erythema was also shown on both the patient and clinician graded assessments. CONCLUSION: Topical PPARalpha agonist applied during clinical practice was relatively safe and effective. This can be applied clinically to various inflammatory skin diseases causing erythema.
Erythema*
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Euphorbia
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Homeostasis
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Humans
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PPAR alpha*
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Rosa
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Skin
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Skin Diseases
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Steroids
;
Transcriptional Activation
6.Kahweol from Coffee Induces Apoptosis by Upregulating Activating Transcription Factor 3 in Human Colorectal Cancer Cells.
Gwang Hun PARK ; Hun Min SONG ; Jin Boo JEONG
Biomolecules & Therapeutics 2017;25(3):337-343
Kahweol as a coffee-specific diterpene has been reported to induce apoptosis in human cancer cells. Although some molecular targets for kahweol-mediated apoptosis have been elucidated, the further mechanism for apoptotic effect of kahweol is not known. Activating transcription factor 3 (ATF3) has been reported to be associated with apoptosis in colorectal cancer. The present study was performed to investigate the molecular mechanism by which kahweol stimulates ATF3 expression and apoptosis in human colorectal cancer cells. Kahweol increased apoptosis in human colorectal cancer cells. It also increased ATF3 expression through the transcriptional activity. The responsible cis-element for ATF3 transcriptional activation by kahweol was CREB located between −147 to −85 of ATF3 promoter. ATF3 overexpression increased kahweol-mediated cleaved PARP, while ATF3 knockdown attenuated the cleavage of PARP by kahweol. Inhibition of ERK1/2 and GSK3β blocked kahweol-mediated ATF3 expression. The results suggest that kahweol induces apoptosis through ATF3-mediated pathway in human colorectal cancer cells.
Activating Transcription Factor 3*
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Apoptosis*
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Coffee*
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Colorectal Neoplasms*
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Humans*
;
Transcriptional Activation
7.Maternal effect genes: Findings and effects on mouse embryo development.
Kyeoung Hwa KIM ; Kyung Ah LEE
Clinical and Experimental Reproductive Medicine 2014;41(2):47-61
Stored maternal factors in oocytes regulate oocyte differentiation into embryos during early embryonic development. Before zygotic gene activation (ZGA), these early embryos are mainly dependent on maternal factors for survival, such as macromolecules and subcellular organelles in oocytes. The genes encoding these essential maternal products are referred to as maternal effect genes (MEGs). MEGs accumulate maternal factors during oogenesis and enable ZGA, progression of early embryo development, and the initial establishment of embryonic cell lineages. Disruption of MEGs results in defective embryogenesis. Despite their important functions, only a few mammalian MEGs have been identified. In this review we summarize the roles of known MEGs in mouse fertility, with a particular emphasis on oocytes and early embryonic development. An increased knowledge of the working mechanism of MEGs could ultimately provide a means to regulate oocyte maturation and subsequent early embryonic development.
Animals
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Cell Lineage
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Embryonic Development*
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Embryonic Structures
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Female
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Fertility
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Mice*
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Oocytes
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Oogenesis
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Organelles
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Pregnancy
;
Transcriptional Activation
8.Dysregulation of NRF2 in Cancer: from Molecular Mechanisms to Therapeutic Opportunities
Byung Jin JUNG ; Hwan Sic YOO ; Sooyoung SHIN ; Young Joon PARK ; Sang Min JEON
Biomolecules & Therapeutics 2018;26(1):57-68
Nuclear factor E2-related factor 2 (NRF2) plays an important role in redox metabolism and antioxidant defense. Under normal conditions, NRF2 proteins are maintained at very low levels because of their ubiquitination and proteasomal degradation via binding to the kelch-like ECH associated protein 1 (KEAP1)-E3 ubiquitin ligase complex. However, oxidative and/or electrophilic stresses disrupt the KEAP1-NRF2 interaction, which leads to the accumulation and transactivation of NRF2. During recent decades, a growing body of evidence suggests that NRF2 is frequently activated in many types of cancer by multiple mechanisms, including the genetic mutations in the KEAP1-NRF2 pathway. This suggested that NRF2 inhibition is a promising strategy for cancer therapy. Recently, several NRF2 inhibitors have been reported with anti-tumor efficacy. Here, we review the mechanisms whereby NRF2 is dysregulated in cancer and its contribution to the tumor development and radiochemoresistance. In addition, among the NRF2 inhibitors reported so far, we summarize and discuss repurposed NRF2 inhibitors with their potential mechanisms and provide new insights to develop selective NRF2 inhibitors.
Metabolism
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NF-E2-Related Factor 2
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Oxidation-Reduction
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Transcriptional Activation
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Ubiquitin
;
Ubiquitination
9.Tyrphostin ErbB2 Inhibitors AG825 and AG879 Have Non-specific Suppressive Effects on gp130/ STAT3 Signaling.
Hyun Kyoung LEE ; In Ae SEO ; Sang Hwa LEE ; Su Young SEO ; Kyung Sup KIM ; Hwan Tae PARK
The Korean Journal of Physiology and Pharmacology 2008;12(5):281-286
Although the interaction between gp130 and the ErbB family has frequently been shown in cancer cells, the mechanism of this interaction remains unclear and controversial. In the present study, we found that specific tyrphostin inhibitors of ErbB2 (AG825 and AG879), but not ErbB1 inhibitor (AG1478), suppressed IL-6-induced tyrosine phosphorylation of STAT3 in schwannoma cells. However, biochemical evidence for transactivation of ErbB2 by IL-6 was not observed. Additionally, the inhibition of ErbB2 expression, with either a specific RNAi or transfection of an ErbB2 mutant lacking the intracellular domain did not inhibit the IL-6-induced tyrosine phosphorylation of STAT3. Thus, it seems that tyrphostins, which are known as specific inhibitors of the ErbB2 kinase, may have non-specific suppressive effects on the IL-6/STAT3 pathway.
Humans
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Interleukin-6
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Neurilemmoma
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Phosphorylation
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Phosphotransferases
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Transcriptional Activation
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Transfection
;
Tyrosine
;
Tyrphostins
10.Epigenetics and Psychiatric Disorders.
Daeyoung OH ; Byung Hwan YANG ; Yu Sang LEE
Journal of the Korean Society of Biological Psychiatry 2008;15(4):243-253
In the post-genomic era, the mechanisms controlling activation of genes are thought to be more important. Gene-environment interactions are crucial in both development and treatment of psychiatric disorders as they are complex genetic disorders. Epigenetics is defined as a change of gene expression that occurs without a change of DNA sequence and can be heritable by certain mechanisms. Epigenetic changes play essential roles in control of gene activation. DNA methylation, chromatin remodeling and RNAi act as key mechanisms for epigenetic modifications of genes. Here, we review the basic mechanisms of epigenetics and discuss their potential involvement of human diseases, including psychiatric disorders.
Base Sequence
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Chromatin Assembly and Disassembly
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DNA Methylation
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Epigenomics
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Gene Expression
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Gene-Environment Interaction
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Humans
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Transcriptional Activation