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 3

The gut microbiota determine the gut-specific ISG signature in GRdim/dim mice and local GC production.

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The gut microbiota determine the gut-specific ISG signature in GRdim/dim...
(A) RNA was isolated from ileum, liver, bone marrow–derived macrophages (BMDM), spleen, and adrenal glands dissected from GRWT/WT (black) and GRdim/dim (white) mice. Stat1 mRNA expression was analyzed via qPCR (n = 4 per group). For each organ, different housekeeping genes were used for normalization. Expression in GRWT/WT mice was set as 1. P values were calculated using Student’s t test. (B–E) Effects of commensal bacteria depletion on ISG expression, p-STAT1 levels, TNF-induced lethality, and GC production. GRWT/WT and GRdim/dim mice were treated with antibiotics (+AB) for 3 weeks. IECs were isolated, and Stat1 (B) and Ifit1 (C) mRNA expression were determined via qPCR (n = 8 per group, combined data of 2 independent experiments). P values were calculated using 2-way ANOVA. (D) TNF dose-response curves of GRWT/WT and GRdim/dim mice treated with (triangles) or without (squares) antibiotics (n = 4–6 per dose). (E–G) Effects of antibiotics on GC production. GRWT/WT and GRdim/dim mice were treated with antibiotics for 3 weeks. Cyp11a1 (E) and Cyp11b1 (F) mRNA expression in IECs were determined via qPCR (n = 4 per group). P values were calculated using 2-way ANOVA. (G) GC production in supernatant of ileum explants of GRWT/WT mice treated without (–AB) or with antibiotics (+AB) (n = 5 per group). P values were calculated by Student’s t test. All bars represent mean ± SEM. ****P < 0.0001; ***P < 0.001; **P ≤ 0.01; *P ≤ 0.05.