Glucocorticoid receptor dimers control intestinal STAT1 and TNF-induced inflammation in mice
Marlies Ballegeer, Kelly Van Looveren, Steven Timmermans, Melanie Eggermont, Sofie Vandevyver, Fabien Thery, Karen Dendoncker, Jolien Souffriau, Jolien Vandewalle, Lise Van Wyngene, Riet De Rycke, Nozomi Takahashi, Peter Vandenabeele, Jan Tuckermann, Holger M. Reichardt, Francis Impens, Rudi Beyaert, Karolien De Bosscher, Roosmarijn E. Vandenbroucke, Claude Libert
Marlies Ballegeer, Kelly Van Looveren, Steven Timmermans, Melanie Eggermont, Sofie Vandevyver, Fabien Thery, Karen Dendoncker, Jolien Souffriau, Jolien Vandewalle, Lise Van Wyngene, Riet De Rycke, Nozomi Takahashi, Peter Vandenabeele, Jan Tuckermann, Holger M. Reichardt, Francis Impens, Rudi Beyaert, Karolien De Bosscher, Roosmarijn E. Vandenbroucke, Claude Libert
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Research Article Endocrinology Immunology

Glucocorticoid receptor dimers control intestinal STAT1 and TNF-induced inflammation in mice

Abstract

TNF is an important mediator in numerous inflammatory diseases, e.g., in inflammatory bowel diseases (IBDs). In IBD, acute increases in TNF production can lead to disease flares. Glucocorticoids (GCs), which are steroids that bind and activate the glucocorticoid receptor (GR), are able to protect animals and humans against acute TNF-induced inflammatory symptoms. Mice with a poor transcriptional response of GR dimer–dependent target genes were studied in a model of TNF-induced lethal inflammation. In contrast to the GRWT/WT mice, these GRdim/dim mice displayed a substantial increase in TNF sensitivity and a lack of protection by the GC dexamethasone (DEX). Unchallenged GRdim/dim mice had a strong IFN-stimulated gene (ISG) signature, along with STAT1 upregulation and phosphorylation. This ISG signature was gut specific and, based on our studies with antibiotics, depended on the gut microbiota. GR dimers directly bound to short DNA sequences in the STAT1 promoter known as inverted repeat negative GRE (IR-nGRE) elements. Poor control of STAT1 in GRdim/dim mice led to failure to repress ISG genes, resulting in excessive necroptosis induction by TNF. Our findings support a critical interplay among gut microbiota, IFNs, necroptosis, and GR in both the basal response to acute inflammatory challenges and pharmacological intervention by GCs.

Authors

Marlies Ballegeer, Kelly Van Looveren, Steven Timmermans, Melanie Eggermont, Sofie Vandevyver, Fabien Thery, Karen Dendoncker, Jolien Souffriau, Jolien Vandewalle, Lise Van Wyngene, Riet De Rycke, Nozomi Takahashi, Peter Vandenabeele, Jan Tuckermann, Holger M. Reichardt, Francis Impens, Rudi Beyaert, Karolien De Bosscher, Roosmarijn E. Vandenbroucke, Claude Libert

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Figure 4

STAT1 is a master regulator of TNF sensitivity.

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STAT1 is a master regulator of TNF sensitivity. (A) RNA was isolated fro...
(A) RNA was isolated from IECs of STAT1+/+ (black bars) and STAT1–/– mice (white bars). Ifit1 and Ifit2 mRNA expression levels were determined via qPCR (n = 4 per group). P values were calculated by Student’s t test. (B–D) STAT1 mediates TNF-induced lethality, intestinal permeability, and cell death. (B) STAT1+/+ (black) and STAT1–/– (white) mice were injected with 35 μg TNF, and survival was monitored (n = 7 per group). Survival curves were analyzed with a log-rank test. (C) As a measure for intestinal permeability, systemic appearance of orally gavaged FITC-dextran in plasma samples was determined 8 hours after TNF injection in STAT1+/+ mice (PBS, n = 7; TNF, n = 14) and in STAT1–/– mice (PBS, n = 7; TNF, n = 15). (D) TUNEL staining was performed on ileum tissue sections and quantified (combined data of 2 independent experiments). P values were calculated using 2-way ANOVA. (E) STAT1 is an important regulator of GRdim/dim TNF sensitivity. Tofacitinib (100 mg/kg) or vehicle was given orally to GRdim/dim mice (n = 10 per group; combined data of 2 independent experiments). Mice received tofacitinib twice a day for 2 days before challenge (20 μg TNF) and 2 times (1 hour before and 8 hours after) on the day of challenge. Survival was monitored and analyzed with a log-rank test. (F) LFCs of TNF-induced ISGs, detected by RNA-seq, in IECs of GRWT/WT mice (black) or GRdim/dim mice (white) injected with 12.5 μg TNF (n = 4 per group). (G) Ifit1 and Ifit2 mRNA expression, measured by qPCR, in IECs of GRWT/WT and GRdim/dim, 8 hours after PBS or 12.5 μg TNF (n = 4 per group). P values were calculated using 2-way ANOVA. All bars represent mean ± SEM. ****P < 0.0001; ***P < 0.001; **P ≤ 0.01; *P ≤ 0.05.