Paneth cell α-defensin misfolding correlates with dysbiosis and ileitis in Crohn’s disease model mice

Crohn’s disease (CD) is an intractable inflammatory bowel disease, and dysbiosis, disruption of the intestinal microbiota, is associated with CD pathophysiology. ER stress, disruption of ER homeostasis in Paneth cells of the small intestine, and α-defensin misfolding have been reported in CD patients. Because α-defensins regulate the composition of the intestinal microbiota, their misfolding may cause dysbiosis. However, whether ER stress, α-defensin misfolding, and dysbiosis contribute to the pathophysiology of CD remains unknown. Here, we show that abnormal Paneth cells with markers of ER stress appear in SAMP1/YitFc, a mouse model of CD, along with disease progression. Those mice secrete reduced-form α-defensins that lack disulfide bonds into the intestinal lumen, a condition not found in normal mice, and reduced-form α-defensins correlate with dysbiosis during disease progression. Moreover, administration of reduced-form α-defensins to wild-type mice induces the dysbiosis. These data provide novel insights into CD pathogenesis induced by dysbiosis resulting from Paneth cell α-defensin misfolding and they suggest further that Paneth cells may be potential therapeutic targets.

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Targeting Mitochondrial Damage as a Therapeutic for Ileal Crohn’s Disease

Cells ◽

10.3390/cells10061349 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1349

Author(s):

Kibrom M. Alula ◽

Dakota N. Jackson ◽

Andrew D. Smith ◽

Daniel S. Kim ◽

Kevin Turner ◽

...

Keyword(s):

Crohn’S Disease ◽

Lipid Metabolism ◽

Crohn's Disease ◽

Paneth Cell ◽

Mitochondrial Damage ◽

Paneth Cells ◽

Cell Phenotype ◽

Type I ◽

Targeted Therapeutics ◽

Gene Signatures

Paneth cell defects in Crohn’s disease (CD) patients (called the Type I phenotype) are associated with worse clinical outcomes. Recent studies have implicated mitochondrial dysfunction in Paneth cells as a mediator of ileitis in mice. We hypothesized that CD Paneth cells exhibit impaired mitochondrial health and that mitochondrial-targeted therapeutics may provide a novel strategy for ileal CD. Terminal ileal mucosal biopsies from adult CD and non-IBD patients were characterized for Paneth cell phenotyping and mitochondrial damage. To demonstrate the response of mitochondrial-targeted therapeutics in CD, biopsies were treated with vehicle or Mito-Tempo, a mitochondrial-targeted antioxidant, and RNA transcriptome was analyzed. During active CD inflammation, the epithelium exhibited mitochondrial damage evident in Paneth cells, goblet cells, and enterocytes. Independent of inflammation, Paneth cells in Type I CD patients exhibited mitochondrial damage. Mito-Tempo normalized the expression of interleukin (IL)-17/IL-23, lipid metabolism, and apoptotic gene signatures in CD patients to non-IBD levels. When stratified by Paneth cell phenotype, the global tissue response to Mito-Tempo in Type I patients was associated with innate immune, lipid metabolism, and G protein-coupled receptor (GPCR) gene signatures. Targeting impaired mitochondria as an underlying contributor to inflammation provides a novel treatment approach for CD.

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266 Transmissive Crohn's Disease-Like Ileitis Is Caused by Functional Dysbiosis in the Intestinal Microbiota Independent of Inflammation-Driven Paneth Cell Failure

Gastroenterology ◽

10.1016/s0016-5085(15)30211-0 ◽

2015 ◽

Vol 148 (4) ◽

pp. S-61

Author(s):

Monika Schaubeck ◽

Thomas Clavel ◽

Ilias Lagkouvardos ◽

Jelena Calasan ◽

Sven-Bastiaan Haange ◽

...

Keyword(s):

Crohn’S Disease ◽

Crohn's Disease ◽

Intestinal Microbiota ◽

Paneth Cell

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Genomic ATG16L1 risk allele-restricted Paneth cell ER stress in quiescent Crohn's disease

Gut ◽

10.1136/gutjnl-2012-303527 ◽

2013 ◽

Vol 63 (7) ◽

pp. 1081-1091 ◽

Cited By ~ 75

Author(s):

J Jasper Deuring ◽

Gwenny M Fuhler ◽

Sergey R Konstantinov ◽

Maikel P Peppelenbosch ◽

Ernst J Kuipers ◽

...

Keyword(s):

Crohn’S Disease ◽

Crohn's Disease ◽

Er Stress ◽

Risk Allele ◽

Paneth Cell

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Mitochondrial dysfunction during loss of prohibitin 1 triggers Paneth cell defects and ileitis

Gut ◽

10.1136/gutjnl-2019-319523 ◽

2020 ◽

Vol 69 (11) ◽

pp. 1928-1938 ◽

Cited By ~ 9

Author(s):

Dakota N Jackson ◽

Marina Panopoulos ◽

William L Neumann ◽

Kevin Turner ◽

Brandi L Cantarel ◽

...

Keyword(s):

Crohn’S Disease ◽

Epithelial Cell ◽

Crohn's Disease ◽

Mitochondrial Dysfunction ◽

Paneth Cell ◽

Paneth Cells ◽

Inner Mitochondrial Membrane ◽

Bowel Diseases ◽

The Impact ◽

Prohibitin 1

ObjectiveAlthough perturbations in mitochondrial function and structure have been described in the intestinal epithelium of Crohn’s disease and ulcerative colitis patients, the role of epithelial mitochondrial stress in the pathophysiology of inflammatory bowel diseases (IBD) is not well elucidated. Prohibitin 1 (PHB1), a major component protein of the inner mitochondrial membrane crucial for optimal respiratory chain assembly and function, is decreased during IBD.DesignMale and female mice with inducible intestinal epithelial cell deletion of Phb1 (Phb1iΔIEC) or Paneth cell-specific deletion of Phb1 (Phb1ΔPC) and Phb1fl/fl control mice were housed up to 20 weeks to characterise the impact of PHB1 deletion on intestinal homeostasis. To suppress mitochondrial reactive oxygen species, a mitochondrial-targeted antioxidant, Mito-Tempo, was administered. To examine epithelial cell-intrinsic responses, intestinal enteroids were generated from crypts of Phb1iΔIEC or Phb1ΔPC mice.ResultsPhb1iΔIEC mice exhibited spontaneous ileal inflammation that was preceded by mitochondrial dysfunction in all IECs and early abnormalities in Paneth cells. Mito-Tempo ameliorated mitochondrial dysfunction, Paneth cell abnormalities and ileitis in Phb1iΔIEC ileum. Deletion of Phb1 specifically in Paneth cells (Phb1ΔPC) was sufficient to cause ileitis. Intestinal enteroids generated from crypts of Phb1iΔIEC or Phb1ΔPC mice exhibited decreased viability and Paneth cell defects that were improved by Mito-Tempo.ConclusionOur results identify Paneth cells as highly susceptible to mitochondrial dysfunction and central to the pathogenesis of ileitis, with translational implications for the subset of Crohn’s disease patients exhibiting Paneth cell defects.

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Sa1868 ER Stress in Paneth Cells of Inactive Crohn's Disease Patients With ATG16L1 Mutations

Gastroenterology ◽

10.1016/s0016-5085(12)61303-1 ◽

2012 ◽

Vol 142 (5) ◽

pp. S-345

Author(s):

J. Jasper Deuring ◽

Maikel P. Peppelenbosch ◽

Ernst J. Kuipers ◽

Colin de Haar ◽

Christien J. van der Woude

Keyword(s):

Crohn’S Disease ◽

Crohn's Disease ◽

Er Stress ◽

Paneth Cells

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OP001. Transmissive Crohn's disease-like ileitis is caused by functional dysbiosis in the intestinal microbiota independent of inflammation-driven Paneth cell failure

Journal of Crohn s and Colitis ◽

10.1093/ecco-jcc/jju027.001 ◽

2015 ◽

Vol 9 (suppl 1) ◽

pp. S1-S1 ◽

Cited By ~ 1

Keyword(s):

Crohn’S Disease ◽

Crohn's Disease ◽

Intestinal Microbiota ◽

Paneth Cell

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Crohn's disease-derived monocytes fail to induce Paneth cell defensins

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1510084112 ◽

2015 ◽

Vol 112 (45) ◽

pp. 14000-14005 ◽

Cited By ~ 34

Author(s):

Lioba F. Courth ◽

Maureen J. Ostaff ◽

Daniela Mailänder-Sánchez ◽

Nisar P. Malek ◽

Eduard F. Stange ◽

...

Keyword(s):

Crohn’S Disease ◽

Crohn's Disease ◽

Mononuclear Cells ◽

Cell Function ◽

Paneth Cell ◽

Constitutive Expression ◽

Paneth Cells ◽

Intestinal Epithelial ◽

Peripheral Blood Mononuclear ◽

Wnt Ligands

Crohn’s disease (CD) is associated with a multitude of genetic defects, many of which likely affect Paneth cell function. Paneth cells reside in the small intestine and produce antimicrobial peptides essential for the host barrier, principally human α-defensin 5 (HD5) and HD6. Patients with CD of the ileum are characterized by reduced constitutive expression of these peptides and, accordingly, compromised antimicrobial barrier function. Here, we present a previously unidentified regulatory mechanism of Paneth cell defensins. Using cultures of human ileal tissue, we showed that the secretome of peripheral blood mononuclear cells (PBMCs) from healthy controls restored the attenuated Paneth cell α-defensin expression characteristic of patients with ileal CD. Analysis of the Wnt pathway in both cultured biopsies and intestinal epithelial cells implicated Wnt ligands driving the PBMC effect, whereas various tested cytokines were ineffective. We further detected another defect in patients with ileal CD, because the PBMC secretomes derived from patients with CD were unable to restore the reduced HD5/HD6 expression. Accordingly, analysis of PBMC subtypes showed that monocytes of patients with CD express significantly lower levels of canonical Wnt ligands, including Wnt3, Wnt3a, Wnt1, and wntless Wnt ligand secretion mediator (Evi/Wls). These studies reveal an important cross-talk between bone marrow-derived cells and epithelial secretory Paneth cells. Defective Paneth cell-mediated innate immunity due to inadequate Wnt ligand stimulation by monocytes provides an additional mechanism in CD. Because defects of Paneth cell function stemming from various etiologies are overcome by Wnt ligands, this mechanism is a potential therapeutic target for this disease.

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Defective ATG16L1-mediated removal of IRE1α drives Crohn’s disease–like ileitis

Journal of Experimental Medicine ◽

10.1084/jem.20160791 ◽

2017 ◽

Vol 214 (2) ◽

pp. 401-422 ◽

Cited By ~ 79

Author(s):

Markus Tschurtschenthaler ◽

Timon E. Adolph ◽

Jonathan W. Ashcroft ◽

Lukas Niederreiter ◽

Richa Bharti ◽

...

Keyword(s):

Crohn’S Disease ◽

Crohn's Disease ◽

Er Stress ◽

Paneth Cell ◽

Protective Role ◽

Dependent Manner ◽

Intestinal Epithelial ◽

Unfolded Protein ◽

Antimicrobial Function ◽

The Unfolded Protein Response

ATG16L1T300A, a major risk polymorphism in Crohn’s disease (CD), causes impaired autophagy, but it has remained unclear how this predisposes to CD. In this study, we report that mice with Atg16l1 deletion in intestinal epithelial cells (IECs) spontaneously develop transmural ileitis phenocopying ileal CD in an age-dependent manner, driven by the endoplasmic reticulum (ER) stress sensor IRE1α. IRE1α accumulates in Paneth cells of Atg16l1ΔIEC mice, and humans homozygous for ATG16L1T300A exhibit a corresponding increase of IRE1α in intestinal epithelial crypts. In contrast to a protective role of the IRE1β isoform, hyperactivated IRE1α also drives a similar ileitis developing earlier in life in Atg16l1;Xbp1ΔIEC mice, in which ER stress is induced by deletion of the unfolded protein response transcription factor XBP1. The selective autophagy receptor optineurin interacts with IRE1α, and optineurin deficiency amplifies IRE1α levels during ER stress. Furthermore, although dysbiosis of the ileal microbiota is present in Atg16l1;Xbp1ΔIEC mice as predicted from impaired Paneth cell antimicrobial function, such structural alteration of the microbiota does not trigger ileitis but, rather, aggravates dextran sodium sulfate–induced colitis. Hence, we conclude that defective autophagy in IECs may predispose to CD ileitis via impaired clearance of IRE1α aggregates during ER stress at this site.

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