scholarly journals BRG1 defines a genomic subset of inflammatory genes transcriptionally controlled by the glucocorticoid receptor

2021 ◽  
Author(s):  
Aikaterini Mechtidou ◽  
Franziska Greulich ◽  
Benjamin A Strickland ◽  
Celine Jouffe ◽  
Filippo M. Cernilogar ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Transcriptional Activation ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Regulatory Elements ◽  
Nuclear Hormone Receptor ◽  
Inflammatory Genes ◽  
Specific Subset ◽  
Primary Mouse ◽  
Independent Functions

Glucocorticoids (such as Dexamethasone) are commonly used immunomodulatory drugs with potent anti-inflammatory effects, whose mechanisms of action remain incompletely understood. They bind to the Glucocorticoid Receptor (GR), a nuclear hormone receptor that acts as a transcription factor to directly control the expression of inflammatory genes. To elucidate the complex molecular mechanisms employed by GR during the suppression of innate immune responses, we have performed proteomics, ChIP-seq, ATAC-seq, RNA-seq and bioinformatics together with genetic and pharmacological loss of function studies in primary mouse macrophages. We found that GR interacts with the ATP-dependent SWI/SNF chromatin remodeling complex to regulate a specific subset of target genes. Here we show that the central catalytic subunit BRG1 is required not only for the transcriptional activation of classical GR target genes such as Fkbp5 or Klf9, but also for the transcriptional repression of cytokines and chemokines such as Ccl2, Cxcl10 or Il1a. We demonstrate that loss of BRG1 activity leads to reduced histone deacetylase (HDAC) function, and consequently increased histone acetylation, at these repressive GR binding sites. Altogether, our findings suggest that GR interacts with BRG1 to assemble a functional co-repressor complex at a defined fraction of macrophage cis-regulatory elements. These results may indicate additional non-classical, remodeling-independent functions of the SWI/SNF complex and may have implications for the development of future immunomodulatory therapies.

scholarly journals Distinct Glucocorticoid Receptor Transcriptional Regulatory Surfaces Mediate the Cytotoxic and Cytostatic Effects of Glucocorticoids

1999 ◽  
Vol 19 (7) ◽  
pp. 5036-5049 ◽  
Author(s):  
Inez Rogatsky ◽  
Adam B. Hittelman ◽  
David Pearce ◽  
Michael J. Garabedian
Keyword(s):  
Glucocorticoid Receptor ◽  
Transcriptional Activation ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Cellular Proliferation ◽  
Antiproliferative Effect ◽  
Glucocorticoid Treatment ◽  
Transcriptional Regulatory ◽  
Human Osteosarcoma Cells ◽  
Transcriptional Regulatory Mechanisms

ABSTRACT Glucocorticoids act through the glucocorticoid receptor (GR), which can function as a transcriptional activator or repressor, to elicit cytostatic and cytotoxic effects in a variety of cells. The molecular mechanisms regulating these events and the target genes affected by the activated receptor remain largely undefined. Using cultured human osteosarcoma cells as a model for the GR antiproliferative effect, we demonstrate that in U20S cells, GR activation leads to irreversible growth inhibition, apoptosis, and repression of Bcl2. This cytotoxic effect is mediated by GR’s transcriptional repression function, since transactivation-deficient mutants and ligands still bring about apoptosis and Bcl2 down-regulation. In contrast, the antiproliferative effect of GR in SAOS2 cells is reversible, does not result in apoptosis or repression of Bcl2, and is a function of the receptor’s ability to stimulate transcription. Thus, the cytotoxic versus cytostatic outcome of glucocorticoid treatment is cell context dependent. Interestingly, the cytostatic effect of glucocorticoids in SAOS2 cells involves multiple GR activation surfaces. GR mutants and ligands that disrupt individual transcriptional activation functions (activation function 1 [AF-1] and AF-2) or receptor dimerization fail to fully inhibit cellular proliferation and, remarkably, discriminate between the targets of GR’s cytostatic action, the cyclin-dependent kinase inhibitors p21Cip1 and p27Kip1. Induction of p21Cip1 is agonist dependent and requires AF-2 but not AF-1 or GR dimerization. In contrast, induction of p27Kip1 is agonist independent, does not require AF-2 or AF-1, but depends on GR dimerization. Our findings indicate that multiple GR transcriptional regulatory mechanisms that employ distinct receptor surfaces are used to evoke either the cytostatic or cytotoxic response to glucocorticoids.

scholarly journals Glucocorticoid Receptor Phosphorylation Differentially Affects Target Gene Expression

2008 ◽  
Vol 22 (8) ◽  
pp. 1754-1766 ◽  
Author(s):  
Weiwei Chen ◽  
Thoa Dang ◽  
Raymond D. Blind ◽  
Zhen Wang ◽  
Claudio N. Cavasotto ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Transcriptional Activation ◽  
Leucine Zipper ◽  
Target Genes ◽  
Divalent Cations ◽  
Phosphorylation Site ◽  
Transcriptional Response ◽  
Receptor Occupancy ◽  
Wild Type ◽  
Interacting Protein

Abstract The glucocorticoid receptor (GR) is phosphorylated at multiple sites within its N terminus (S203, S211, S226), yet the role of phosphorylation in receptor function is not understood. Using a range of agonists and GR phosphorylation site-specific antibodies, we demonstrated that GR transcriptional activation is greatest when the relative phosphorylation of S211 exceeds that of S226. Consistent with this finding, a replacement of S226 with an alanine enhances GR transcriptional response. Using a battery of compounds that perturb different signaling pathways, we found that BAPTA-AM, a chelator of intracellular divalent cations, and curcumin, a natural product with antiinflammatory properties, reduced hormone-dependent phosphorylation at S211. This change in GR phosphorylation was associated with its decreased nuclear retention and transcriptional activation. Molecular modeling suggests that GR S211 phosphorylation promotes a conformational change, which exposes a novel surface potentially facilitating cofactor interaction. Indeed, S211 phosphorylation enhances GR interaction with MED14 (vitamin D receptor interacting protein 150). Interestingly, in U2OS cells expressing a nonphosphorylated GR mutant S211A, the expression of IGF-binding protein 1 and interferon regulatory factor 8, both MED14-dependent GR target genes, was reduced relative to cells expressing wild-type receptor across a broad range of hormone concentrations. In contrast, the induction of glucocorticoid-induced leucine zipper, a MED14-independent GR target, was similar in S211A- and wild-type GR-expressing cells at high hormone levels, but was reduced in S211A cells at low hormone concentrations, suggesting a link between GR phosphorylation, MED14 involvement, and receptor occupancy. Phosphorylation also affected the magnitude of repression by GR in a gene-selective manner. Thus, GR phosphorylation at S211 and S226 determines GR transcriptional response by modifying cofactor interaction. Furthermore, the effect of GR S211 phosphorylation is gene specific and, in some cases, dependent upon the amount of activated receptor.

scholarly journals Transcriptional activation and repression by Fos are independent functions: the C terminus represses immediate-early gene expression via CArG elements.

1990 ◽  
Vol 10 (8) ◽  
pp. 4243-4255 ◽  
Author(s):  
D Gius ◽  
X M Cao ◽  
F J Rauscher ◽  
D R Cohen ◽  
T Curran ◽  
...  
Keyword(s):  
Gene Expression ◽  
Amino Acids ◽  
Transcriptional Activation ◽  
Leucine Zipper ◽  
Regulatory Element ◽  
Regulatory Elements ◽  
Early Gene ◽  
Immediate Early ◽  
Striking Similarity ◽  
Independent Functions

The Fos-Jun complex has been shown to activate transcription through the regulatory element known as the AP-1 binding site. We show that Fos down regulates several immediate-early genes (c-fos, Egr-1, and Egr-2) after mitogenic stimulation. Specifically, we demonstrate that the target for this repression is a sequence of the form CC(A/T)6GG, also known as a CArG box. Whereas Fos bound to the AP-1 site through a domain rich in basic amino acids and associated with Jun via a leucine zipper interaction, mutant Fos proteins lacking these structures were still capable of causing repression. Furthermore, Jun neither enhanced nor inhibited down regulation by Fos. Critical residues required for repression are located within the C-terminal 27 amino acids of c-Fos, since v-Fos and C-terminal truncations of c-Fos did not down regulate. In addition, transfer of 180 c-Fos C-terminal amino acids to Jun conferred upon it the ability to repress. Finally, Fra-1, a Fos-related protein which has striking similarity to Fos in its C-terminal 40 amino acids, also down regulated Egr-1 expression. Thus, Fos is a transcriptional regulator that can activate or repress gene expression by way of two separate functional domains that act on distinct regulatory elements.

scholarly journals Identification of key genes and associated pathways in neuroendocrine tumors through bioinformatics analysis and predictions of small drug molecules

2020 ◽  
Author(s):  
Praveenkumar Devarbhavi ◽  
Basavaraj Vastrad ◽  
Anandkumar Tengli ◽  
Chanabasayya Vastrad ◽  
Iranna Kotturshetti
Keyword(s):  
Drug Target ◽  
Target Gene ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Regulatory Elements ◽  
Future Research ◽  
High Morbidity ◽  
Hub Genes ◽  
Go Enrichment ◽  
Significant Difference

AbstractNeuroendocrine tumor (NET) is one of malignant cancer and is identified with high morbidity and mortality rates around the world. With indigent clinical outcomes, potential biomarkers for diagnosis, prognosis and drug target are crucial to explore. The aim of this study is to examine the gene expression module of NET and to identify potential diagnostic and prognostic biomarkers as well as to find out new drug target. The differentially expressed genes (DEGs) identified from GSE65286 dataset was used for pathway enrichment analyses and gene ontology (GO) enrichment analyses and protein - protein interaction (PPI) analysis and module analysis. Moreover, miRNAs and transcription factors (TFs) that regulated the up and down regulated genes were predicted. Furthermore, validation of hub genes was performed. Finally, molecular docking studies were performed. DEGs were identified, including 453 down regulated and 459 up regulated genes. Pathway and GO enrichment analysis revealed that DEGs were enriched in sucrose degradation, creatine biosynthesis, anion transport and modulation of chemical synaptic transmission. Important hub genes and target genes were identified through PPI network, modules, target gene - miRNA network and target gene - TF network. Finally, survival analyses, receiver operating characteristic (ROC) curve and RT-PCR validated the significant difference of ATP1A1, LGALS3, LDHA, SYK, VDR, OBSL1, KRT40, WWOX, NINL and PPP2R2B between metastatic NET and normal controls. In conclusion, the DEGs and hub genes with their regulatory elements identified in this study will help us understand the molecular mechanisms underlying NET and provide candidate targets for future research.

scholarly journals The methylated-DNA binding protein MBD2 enhances NGFI-A (egr-1)-mediated transcriptional activation of the glucocorticoid receptor

2014 ◽  
Vol 369 (1652) ◽  
pp. 20130513 ◽  
Author(s):  
Ian C. G. Weaver ◽  
Ian C. Hellstrom ◽  
Shelley E. Brown ◽  
Stephen D. Andrews ◽  
Sergiy Dymov ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Transcriptional Activation ◽  
Target Genes ◽  
Protein A ◽  
Site Directed Mutagenesis ◽  
Signalling Pathways ◽  
Hek 293 ◽  
293 Cells ◽  
Exon 1 ◽  
Inducible Protein

Variations in maternal care in the rat influence the epigenetic state and transcriptional activity of glucocorticoid receptor (GR) gene in the hippocampus. The mechanisms underlying this maternal effect remained to be defined, including the nature of the relevant maternally regulated intracellular signalling pathways. We show here that increased maternal licking/grooming (LG), which stably enhances hippocampal GR expression, paradoxically increases hippocampal expression of the methyl-CpG binding domain protein-2 (MBD2) and MBD2 binding to the exon 1 7 GR promoter. Knockdown experiments of MBD2 in hippocampal primary cell culture show that MBD2 is required for activation of exon 1 7 GR promoter. Ectopic co-expression of nerve growth factor-inducible protein A (NGFI-A) with MBD2 in HEK 293 cells with site-directed mutagenesis of the NGFI-A response element within the methylated exon 1 7 GR promoter supports the hypothesis that MBD2 collaborates with NGFI-A in binding and activation of this promoter. These data suggest a possible mechanism linking signalling pathways, which are activated by behavioural stimuli and activation of target genes.

scholarly journals KAP1-associated transcriptional inhibitory complex regulates C2C12 myoblasts differentiation and mitochondrial biogenesis via miR-133a repression

2020 ◽  
Vol 11 (9) ◽  
Author(s):  
Jialing Zhang ◽  
Chaoju Hua ◽  
Yu Zhang ◽  
Peng Wei ◽  
Yaping Tu ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Affinity Purification ◽  
Regulatory Elements ◽  
C2c12 Myoblasts ◽  
Regulatory Machinery ◽  
New Ideas ◽  
Biogenesis Of Mitochondria

Abstract The differentiation of myoblasts plays a key role in the growth of biological individuals and the reconstruction of muscle tissue. Several microRNAs are significantly upregulated during the differentiation of myoblasts and their target genes have been explored. However, the molecular mechanisms underlying the transcriptional regulation of microRNAs remain elusive. In the present study, we found that the expression of miR-133a is increased during the differentiation of C2C12 myoblasts. miR-133a mimic is sufficient to induce the biogenesis of mitochondria and differentiation of C2C12 myoblasts whereas miR-133a inhibitor abolishes cell differentiation. Using CRISPR affinity purification in situ of regulatory elements (CAPTURE) technique, we further dissected the regulatory mechanisms of miR-133a expression and found that KAP1-associated transcription complex accounts for the suppression of miR-133a in C2C12 myoblasts. Knockdown of KAP1 increased the expression of miR-133a, which contributed to the biogenesis of mitochondria and differentiation of C2C12 myoblasts. To our knowledge, this is the first study using the CAPTURE technology to identify the regulatory factors of miR-133a during cell differentiation, which may provide new ideas for understanding the precision regulatory machinery of microRNAs during different biological processes.

scholarly journals Glucocorticoid regulates mesenchymal cell differentiation required for perinatal lung morphogenesis and function

2020 ◽  
Vol 319 (2) ◽  
pp. L239-L255
Author(s):  
James P. Bridges ◽  
Parvathi Sudha ◽  
Dakota Lipps ◽  
Andrew Wagner ◽  
Minzhe Guo ◽  
...  
Keyword(s):  
Lung Function ◽  
Glucocorticoid Receptor ◽  
Progenitor Cell ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Receptor Gene ◽  
Mesenchymal Cell ◽  
Alveolar Type ◽  
Lung Maturation ◽  
Glucocorticoid Receptor Gene

While antenatal glucocorticoids are widely used to enhance lung function in preterm infants, cellular and molecular mechanisms by which glucocorticoid receptor (GR) signaling influences lung maturation remain poorly understood. Deletion of the glucocorticoid receptor gene ( Nr3c1) from fetal pulmonary mesenchymal cells phenocopied defects caused by global Nr3c1 deletion, while lung epithelial- or endothelial-specific Nr3c1 deletion did not impair lung function at birth. We integrated genome-wide gene expression profiling, ATAC-seq, and single cell RNA-seq data in mice in which GR was deleted or activated to identify the cellular and molecular mechanisms by which glucocorticoids control prenatal lung maturation. GR enhanced differentiation of a newly defined proliferative mesenchymal progenitor cell (PMP) into matrix fibroblasts (MFBs), in part by directly activating extracellular matrix-associated target genes, including Fn1, Col16a4, and Eln and by modulating VEGF, JAK-STAT, and WNT signaling. Loss of mesenchymal GR signaling blocked fibroblast progenitor differentiation into mature MFBs, which in turn increased proliferation of SOX9+ alveolar epithelial progenitor cells and inhibited differentiation of mature alveolar type II (AT2) and AT1 cells. GR signaling controls genes required for differentiation of a subset of proliferative mesenchymal progenitors into matrix fibroblasts, in turn, regulating signals controlling AT2/AT1 progenitor cell proliferation and differentiation and identifying cells and processes by which glucocorticoid signaling regulates fetal lung maturation.

scholarly journals Determination of the consensus DNA-binding sequence and a transcriptional activation domain for ESE-2

2006 ◽  
Vol 398 (3) ◽  
pp. 497-507 ◽  
Author(s):  
Yeon Sook Choi ◽  
Satrajit Sinha
Keyword(s):  
Transcription Factors ◽  
Dna Binding ◽  
Transcriptional Activation ◽  
Target Genes ◽  
Regulatory Elements ◽  
Activation Domain ◽  
Transcriptional Activation Domain ◽  
Ets Proteins ◽  
Flanking Sequences ◽  
Binding Sequence

The ESE (epithelium-specific Ets) subfamily of Ets transcription factors plays an important role in regulating gene expression in a variety of epithelial cell types. Although ESE proteins have been shown to bind to regulatory elements of some epithelial genes, the optimal DNA-binding sequence has not been experimentally ascertained for any member of the ESE subfamily of transcription factors. This has made the identification and validation of their targets difficult. We are studying ESE-2 (Elf5), which is highly expressed in epithelial cells of many tissues including skin keratinocytes. Here, we identify the preferred DNA-binding site of ESE-2 by performing CASTing (cyclic amplification and selection of targets) experiments. Our analysis shows that the optimal ESE-2 consensus motif consists of a GGA core and an AT-rich 5′- and 3′-flanking sequences. Mutational and competition experiments demonstrate that the flanking sequences that confer high DNA-binding affinity for ESE-2 show considerable differences from the known consensus DNA-binding sites of other Ets proteins, thus reinforcing the idea that the flanking sequences may impart recognition specificity for Ets proteins. In addition, we have identified a novel isoform of murine ESE-2, ESE-2L, that is generated by use of a hitherto unreported new exon and an alternate promoter. Interestingly, transient transfection assays with an optimal ESE-2 responsive reporter show that both ESE-2 and ESE-2L are weak transactivators. However, similar studies utilizing GAL4 chimaeras of ESE-2 demonstrate that while the DNA-binding ETS (E twenty-six) domain functions as a repressor, the PNT (pointed domain) of ESE-2 can act as a potent transcriptional activation domain. This novel transactivating property of PNT is also shared by ESE-3, another ESE family member. Identification of the ESE-2 consensus site and characterization of the transcriptional activation properties of ESE-2 shed new light on its potential as a regulator of target genes.

scholarly journals A Novel Isoform of Human LZIP Negatively Regulates the Transactivation of the Glucocorticoid Receptor

2009 ◽  
Vol 23 (11) ◽  
pp. 1746-1757 ◽  
Author(s):  
Hyereen Kang ◽  
Yoon Suk Kim ◽  
Jesang Ko
Keyword(s):  
Amino Acids ◽  
Glucocorticoid Receptor ◽  
Transcriptional Activation ◽  
Leucine Zipper ◽  
Target Genes ◽  
Transmembrane Domain ◽  
Negative Regulator ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Basic Leucine Zipper

Abstract The human leucine zipper protein (LZIP) is a basic leucine zipper transcription factor that is involved in leukocyte migration, tumor suppression, and endoplasmic reticulum stress-associated protein degradation. Although evidence suggests a diversity of roles for LZIP, its function is not fully understood, and the subcellular localization of LZIP is still controversial. We identified a novel isoform of LZIP and characterized its function in ligand-induced transactivation of the glucocorticoid receptor (GR) in COS-7 and HeLa cells. A novel isoform of human LZIP designated as “sLZIP” contains a deleted putative transmembrane domain (amino acids 229–245) of LZIP and consists of 345 amino acids. LZIP and sLZIP were ubiquitously expressed in a variety of cell lines and tissues, with LZIP being much more common. sLZIP was mainly localized in the nucleus, whereas LZIP was located in the cytoplasm. Unlike LZIP, sLZIP was not involved in the chemokine-mediated signal pathway. sLZIP recruited histone deacetylases (HDACs) to the promoter region of the mouse mammary tumor virus luciferase reporter gene and enhanced the activities of HDACs, resulting in suppression of expression of the GR target genes. Our findings suggest that sLZIP functions as a negative regulator in glucocorticoid-induced transcriptional activation of GR by recruitment and activation of HDACs.

scholarly journals Glucocorticoid receptor-PPARα axis in fetal mouse liver prepares neonates for milk lipid catabolism

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Gianpaolo Rando ◽  
Chek Kun Tan ◽  
Nourhène Khaled ◽  
Alexandra Montagner ◽  
Nicolas Leuenberger ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Transcriptional Activation ◽  
Milk Fat ◽  
Target Genes ◽  
Fetal Liver ◽  
Milk Lipid ◽  
Epigenetic Switch ◽  
Lipid Catabolism ◽  
Fetal Mouse Liver ◽  
Neonatal Liver

In mammals, hepatic lipid catabolism is essential for the newborns to efficiently use milk fat as an energy source. However, it is unclear how this critical trait is acquired and regulated. We demonstrate that under the control of PPARα, the genes required for lipid catabolism are transcribed before birth so that the neonatal liver has a prompt capacity to extract energy from milk upon suckling. The mechanism involves a fetal glucocorticoid receptor (GR)-PPARα axis in which GR directly regulates the transcriptional activation of PPARα by binding to its promoter. Certain PPARα target genes such as Fgf21 remain repressed in the fetal liver and become PPARα responsive after birth following an epigenetic switch triggered by β-hydroxybutyrate-mediated inhibition of HDAC3. This study identifies an endocrine developmental axis in which fetal GR primes the activity of PPARα in anticipation of the sudden shifts in postnatal nutrient source and metabolic demands.

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