Glucocorticoid receptor dimers control intestinal STAT1 and TNF-induced inflammation in mice
Marlies Ballegeer, … , Roosmarijn E. Vandenbroucke, Claude Libert
Marlies Ballegeer, … , Roosmarijn E. Vandenbroucke, Claude Libert
Published May 10, 2018
Citation Information: J Clin Invest. 2018;128(8):3265-3279. https://doi.org/10.1172/JCI96636.
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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 1

IEC GR and GR dimers play an essential role in protection against TNF-induced lethality, gut permeability, damage, and cell death.

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IEC GR and GR dimers play an essential role in protection against TNF-in...
(A) GRfl/fl (n = 14 per group, black) and GRVillinKO mice (n = 7 per group, white) were pretreated with PBS (squares) or with 10 mg/kg DEX (triangles). Thirty minutes later, mice were injected with 35 μg TNF, and lethality was monitored. P values for survival curves were analyzed with a log-rank test (combined data of 2 independent experiments). (B) TNF dose-response curves of GRWT/WT (black) and GRdim/dim (white) mice pretreated with PBS (squares) or with 10 mg/kg DEX (triangles) for 30 minutes (n = 8–10 per group; combined data of 2 independent experiments). (C) LD50 values of TNF are depicted on top of each bar for each group. 95% confidence intervals were calculated for the LD50 of each group. (D–F) GRWT/WT and GRdim/dim mice were injected with PBS or 12.5 μg TNF (n = 10 per group; combined data of 2 independent experiments). Asterisks refer to significant differences compared with PBS control, unless indicated otherwise. (D) Relative permeability, 8 hours after TNF challenge, is based upon systemic appearance of orally gavaged FITC-dextran in plasma samples. Standard H&E (E) and TUNEL staining (F) on ileum samples 8 hours after TNF were scored in order to calculate bowel damage and TUNEL scores, respectively. Notice a perfect appearance of GRWT/WT villi, but villi damage, shortening, cell death, and loss of goblet cells in GRdim/dim as well as TUNEL signals at villi tops and crypts. Scale bars: 50 μm. Bars represent mean ± SEM. P values were calculated using 2-way ANOVA. ****P < 0.0001 ***P ≤ 0.001; **P ≤ 0.01; *P ≤ 0.05.