scholarly journals Glucocorticoid signaling induces transcriptional memory and universally reversible chromatin changes

2021 ◽  
Vol 4 (10) ◽  
pp. e202101080
Author(s):  
Melissa Bothe ◽  
René Buschow ◽  
Sebastiaan H Meijsing
Keyword(s):  
Single Cell Analysis ◽  
Stress Hormones ◽  
Transcriptional Response ◽  
Chromatin Accessibility ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Glucocorticoid Signaling ◽  
Transcriptional Memory ◽  
Induced Changes ◽  
Robust Response

Glucocorticoids are stress hormones that elicit cellular responses by binding to the glucocorticoid receptor, a ligand-activated transcription factor. The exposure of cells to this hormone induces wide-spread changes in the chromatin landscape and gene expression. Previous studies have suggested that some of these changes are reversible whereas others persist even when the hormone is no longer around. However, when we examined chromatin accessibility in human airway epithelial cells after hormone washout, we found that the hormone-induced changes were universally reversed after 1 d. Moreover, priming of cells by a previous exposure to hormone, in general, did not alter the transcriptional response to a subsequent encounter of the same cue except for one gene, ZBTB16, that displays transcriptional memory manifesting itself as a more robust transcriptional response upon repeated hormone stimulation. Single-cell analysis revealed that the more robust response is driven by a higher probability of primed cells to activate ZBTB16 and by a subset of cells that express the gene at levels that are higher than the induction levels observed for naïve cells.

scholarly journals Glucocorticoid receptor activation induces gene-specific transcriptional memory and universally reversible changes in chromatin accessibility

2021 ◽  
Author(s):  
Melissa Bothe ◽  
René Buschow ◽  
Sebastiaan H. Meijsing
Keyword(s):  
Glucocorticoid Receptor ◽  
Transcriptional Repression ◽  
Single Gene ◽  
Transcriptional Response ◽  
Receptor Activation ◽  
Chromatin Accessibility ◽  
Airway Epithelial Cells ◽  
Transcriptional Responses ◽  
Transcriptional Memory ◽  
Induced Changes

AbstractGlucocorticoids are stress hormones that elicit cellular responses by binding to the glucocorticoid receptor (GR), a ligand-activated transcription factor. The exposure of cells to this hormone induces wide-spread changes in the chromatin landscape and gene expression. Previous studies have suggested that some of these changes are reversible whereas others persist even when the hormone is no longer around. However, when we examined chromatin accessibility in human airway epithelial cells after hormone washout, we found that the hormone-induced changes were universally reversed after one day. Reversibility of hormone-induced changes are found for GR-occupied opening sites and also for closing sites that typically lack GR occupancy. These closing sites are enriched near repressed genes, suggesting that transcriptional repression by GR does not require nearby GR binding. Mirroring what we say in terms of chromatin accessibility, we found that transcriptional responses to hormone are universally reversable. Moreover, priming of cells by a previous exposure to hormone, in general, did not alter the transcriptional response to a subsequent encounter of the same cue. Interestingly, despite the short-lived nature of hormone-induced changes in the chromatin landscape, we identified a single gene, ZBTB16, that displays transcriptional memory manifesting itself as a more robust transcriptional response upon repeated hormone stimulation. Single-cell analysis revealed that the more robust response is driven by a higher probability of primed cells to activate ZBTB16 and by a subset of cells that express the gene at levels that are higher than the induction levels observed for naïve cells. Although our study shows that hormone-induced changes are typically reversable, exposure to hormone can induce gene-specific changes in the response to subsequent exposures which may play a role in habituation to stressors and changes in glucocorticoid sensitivity.

scholarly journals Glucocorticoids can activate the α-ENaC gene promoter independently of SGK1

2009 ◽  
Vol 423 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Niall McTavish ◽  
Jennet Getty ◽  
Ann Burchell ◽  
Stuart M. Wilson
Keyword(s):  
Transcriptional Activity ◽  
Transcriptional Response ◽  
Gene Promoter ◽  
Airway Epithelial Cells ◽  
Na Channel ◽  
Airway Epithelial ◽  
Transcriptional Responses ◽  
Α Subunit ◽  
Inactive Form ◽  
Phosphoinositide 3 Kinase

The role of SGK1 (serum- and glucocorticoid-induced protein kinase 1) in the glucocorticoid induction of α-ENaC (epithelial Na+ channel α subunit) gene transcription was explored by monitoring the transcriptional activity of a luciferase-linked, α-ENaC reporter gene construct (pGL3-KR1) expressed in H441 airway epithelial cells. Dexamethasone evoked a concentration-dependent (EC50∼4 μM) increase in transcriptional activity dependent upon a glucocorticoid response element in the α-ENaC sequence. Although dexamethasone also activated endogenous SGK1, artificially increasing cellular SGK1 activity by expressing a constitutively active SGK1 mutant (SGK1-S422D) in hormone-deprived cells did not activate pGL3-KR1. Moreover, expression of catalytically inactive SGK1 (SGK1-K127A) suppressed the activation of endogenous SGK1 without affecting the transcriptional response to dexamethasone. Increasing cellular PI3K (phosphoinositide 3-kinase) activity by expressing a membrane-anchored form of the catalytic PI3K-P110α subunit [CD2 (cluster of differentiation 2)-P110α] also activated endogenous SGK1 without affecting pGL3-KR1activity. A catalytically inactive form of CD2-P110α (R1130P), on the other hand, prevented the dexamethasone-induced activation of SGK1, but did not inhibit the activation of pGL3-KR1. However, expression of SGK1-S422D or CD2-P110α enhanced the transcriptional responses to maximally effective concentrations of dexamethasone and this effect occurred with no change in EC50. Dexamethasone-induced (0.3–300 nM) activation of pGL3-KR1 was unaffected by inhibitors of PI3K (PI-103 and wortmanin) and by rapamycin, a selective inhibitor of the TORC1 (target of rapamycin complex 1) signalling complex. Dexamethasone-induced activation of the α-ENaC gene promoter can thus occur independently of SGK1/PI3K, although this pathway does provide a mechanism that allows this transcriptional response to dexamethasone to be enhanced.

scholarly journals IL-13-induced changes in endogenous glucocorticoid metabolism in the lung regulate the proasthmatic response

2012 ◽  
Vol 303 (5) ◽  
pp. L382-L390 ◽  
Author(s):  
Maureen B. Josephson ◽  
Junfang Jiao ◽  
Shuyun Xu ◽  
Aihua Hu ◽  
Chinmay Paranjape ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Airway Hyperresponsiveness ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Pulmonary Epithelium ◽  
Lung Fluid ◽  
Peripheral Lung ◽  
Induced Changes ◽  
Fluid Levels ◽  
Glucocorticoid Metabolism

Endogenous glucocorticoid (GC) activation is regulated by the intracellular GC-activating and -inactivating enzymes 11β-hydroxysteroid dehydrogenase (11β-HSD)1 and 11β-HSD2, respectively, that catalyze interconversion of inert cortisone and its bioactive metabolite cortisol. Because endogenous GCs are critically implicated in suppressing the asthmatic state, this study examined the roles of the 11β-HSD enzymes in regulating GC activation and bronchoprotection during proasthmatic stimulation. Airway hyperresponsiveness to methacholine and inflammation were assessed in rabbits following inhalation of the proasthmatic/proinflammatory cytokine IL-13 with and without pretreatment with the 11β-HSD inhibitor carbenoxolone (CBX). Additionally, IL-13-induced changes in 11β-HSD isozyme expression and GC metabolism were examined in epithelium-intact and -denuded tracheal segments and peripheral lung tissues. Finally, the effects of pretreatment with CBX or 11β-HSD2-targeted siRNAs were investigated with respect to cortisol prevention of IL-13-induced airway constrictor hyperresponsiveness and eotaxin-3 production by airway epithelial cells. IL-13-exposed rabbits exhibited airway hyperresponsiveness, inflammation, and elevated bronchoalveolar lung fluid levels of eotaxin-3. These responses were inhibited by pretreatment with CBX, suggesting a permissive proasthmatic role for 11β-HSD2. Supporting this concept, extended studies demonstrated that 1) IL-13-treated tracheal epithelium and peripheral lung tissues exhibit upregulated 11β-HSD2 activity, 2) the latter impairs cortisone-induced cortisol accumulation and the ability of administered cortisol to prevent both IL-13-induced heightened airway contractility and eotaxin-3 release from epithelial cells, and 3) these proasthmatic responses are prevented by cortisol administration in the presence of 11β-HSD2 inhibition. Collectively, these data demonstrate that the proasthmatic effects of IL-13 are enabled by impaired endogenous GC activation in the lung that is attributed to upregulation of 11β-HSD2 in the pulmonary epithelium.

scholarly journals The SWI/SNF-Related, Matrix Associated, Actin-Dependent Regulator of Chromatin A4 Core Complex Represses Respiratory Syncytial Virus-Induced Syncytia Formation and Subepithelial Myofibroblast Transition

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaofang Xu ◽  
Dianhua Qiao ◽  
Chenyang Dong ◽  
Morgan Mann ◽  
Roberto P. Garofalo ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Rna Polymerase Ii ◽  
Chromatin Accessibility ◽  
Airway Epithelial Cells ◽  
Open Chromatin ◽  
Airway Epithelial ◽  
Mesenchymal Transition ◽  
Epithelial Plasticity ◽  
Rsv Infection ◽  
Syncytial Virus

Epigenetics plays an important role in the priming the dynamic response of airway epithelial cells to infectious and environmental stressors. Here, we examine the epigenetic role of the SWI/SNF Related, Matrix Associated, Actin Dependent Regulator of Chromatin A4 (SMARCA4) in the epithelial response to RSV infection. Depletion of SMARCA4 destabilized the abundance of the SMARCE1/ARID1A SWI/SNF subunits, disrupting the innate response and triggering a hybrid epithelial/mesenchymal (E/M) state. Assaying SMARCA4 complex-regulated open chromatin domains by transposase cleavage -next generation sequencing (ATAC-Seq), we observed that the majority of cleavage sites in uninfected cells have reduced chromatin accessibility. Paradoxically, SMARCA4 complex-depleted cells showed enhanced RSV-inducible chromatin opening and gene expression in the EMT pathway genes, MMP9, SNAI1/2, VIM, and CDH2. Focusing on the key MMP9, we observed that SMARCA4 complex depletion reduced basal BRD4 and RNA Polymerase II binding, but enhanced BRD4/Pol II binding in response to RSV infection. In addition, we observed that MMP9 secretion in SMARCA4 complex deficient cells contributes to mesenchymal transition, cellular fusion (syncytia) and subepithelial myofibroblast transition. We conclude the SMARCA4 complex is a transcriptional repressor of epithelial plasticity, whose depletion triggers a hybrid E/M state that affects the dynamic response of the small airway epithelial cell in mucosal remodeling via paracrine MMP9 activity.

scholarly journals TRAIL (CD253) Sensitizes Human Airway Epithelial Cells to Toxin-Induced Cell Death

2018 ◽  
Author(s):  
Yinghui Rong ◽  
Jennifer Westfall ◽  
Dylan Ehrbar ◽  
Timothy LaRocca ◽  
Nicholas J. Mantis
Keyword(s):  
Cell Death ◽  
Epithelial Cell ◽  
Airway Epithelial Cell ◽  
Cell Damage ◽  
Transcriptional Response ◽  
Airway Epithelial Cells ◽  
Epithelial Cell Line ◽  
Airway Epithelial ◽  
Ricin Toxin ◽  
Human Airway

ABSTRACTInhalation of ricin toxin is associated with the onset of acute respiratory distress syndrome (ARDS), characterized by hemorrhage, inflammatory exudates, and tissue edema, as well as the near complete destruction of the lung epithelium. Here we report that the Calu-3 human airway epithelial cell line is relatively impervious to the effects of ricin, with little evidence of cell death even upon exposure to microgram amounts of toxin. However, the addition of exogenous soluble TNF-Related Apoptosis Inducing Ligand (TRAIL; CD253) dramatically sensitized Calu-3 cells to ricin-induced apoptosis. Calu-3 cell killing in response to ricin and TRAIL was reduced upon the addition of caspase-8 and caspase-3/7 inhibitors, but not caspase 9 inhibitors, consistent with involvement of extrinsic apoptotic pathways in cell death. We employed nCounter Technology to define the transcriptional response of Calu-3 cells to ricin, TRAIL, and the combination of ricin plus TRAIL. An array of genes associated with inflammation-and cell death were significantly up regulated upon treatment with ricin toxin, and further amplified upon addition of TRAIL. Of particular note was IL-6, whose expression in Calu-3 cells increased 300-fold upon ricin treatment and more than 750-fold upon ricin and TRAIL treatment. IL-6 secretion by Calu-3 cells was confirmed by cytometric bead array. Based on these finding, we speculate that the severe airway epithelial cell damage observed in animal models following ricin exposure is a result of a positive feedback loop driven by pro-inflammatory cytokines like TRAIL and IL-6.

scholarly journals Circadian variation in pulmonary inflammatory responses is independent of rhythmic glucocorticoid signaling in airway epithelial cells

2018 ◽  
Vol 33 (1) ◽  
pp. 126-139 ◽  
Author(s):  
Louise M. Ince ◽  
Zhenguang Zhang ◽  
Stephen Beesley ◽  
Ryan M. Vonslow ◽  
Ben R. Saer ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Responses ◽  
Circadian Variation ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Glucocorticoid Signaling

scholarly journals Nascent transcript analysis of glucocorticoid crosstalk with TNF defines primary and cooperative inflammatory repression

2019 ◽  
Author(s):  
Sarah K. Sasse ◽  
Margaret Gruca ◽  
Mary A. Allen ◽  
Vineela Kadiyala ◽  
Tengyao Song ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Transcriptional Repression ◽  
Regulatory Elements ◽  
Chromatin Accessibility ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Nascent Transcript ◽  
Regulatory Regions ◽  
Anti Inflammatory ◽  
Transcriptional Induction

AbstractThe glucocorticoid receptor (GR) binds to specific DNA sequences and directly induces transcription of anti-inflammatory genes that contribute to cytokine repression, frequently in cooperation with NF-kB. Whether inflammatory repression also occurs through local interactions between GR and inflammatory gene regulatory elements remains controversial. Here, using Global Run-on Sequencing (GRO-seq) in human airway epithelial cells, we show that glucocorticoid signaling represses transcription within 10 minutes. Many repressed regulatory regions reside within ‘hyper-ChIPable’ genomic regions that are subject to non-specific interactions with some antibodies. When this was accounted for, we determined that transcriptional repression occurs without local GR occupancy. Instead, widespread transcriptional induction through canonical GR binding sites is associated with reciprocal repression of distal TNF-regulated enhancers through a chromatin-dependent process, as evidenced by chromatin accessibility and enhancer-reporter assays. Simultaneously, transcriptional induction of key anti-inflammatory effectors is decoupled from primary repression through cooperation between GR and NF-kB at a subset of regulatory regions. Thus, glucocorticoids exert bimodal restraints on inflammation characterized by rapid primary transcriptional repression without local GR occupancy and secondary anti-inflammatory effects resulting from transcriptional cooperation between GR and NF-kB.

Sign in / Sign up

Export Citation Format

Share Document