scholarly journals Enhanced susceptibility to chemically induced colitis caused by excessive endosomal TLR signaling in LRBA-deficient mice

2019 ◽  
Vol 116 (23) ◽  
pp. 11380-11389 ◽  
Author(s):  
Kuan-wen Wang ◽  
Xiaoming Zhan ◽  
William McAlpine ◽  
Zhao Zhang ◽  
Jin Huk Choi ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Intestinal Inflammation ◽  
Type I ◽  
Induced Mutations ◽  
Tlr Signaling ◽  
Nonsense Mutations ◽  
Chemically Induced ◽  
Inflammatory Bowel ◽  
Deficient Mice ◽  
Stimulation Of

LPS-responsive beige-like anchor (LRBA) protein deficiency in humans causes immune dysregulation resulting in autoimmunity, inflammatory bowel disease (IBD), hypogammaglobulinemia, regulatory T (Treg) cell defects, and B cell functional defects, but the cellular and molecular mechanisms responsible are incompletely understood. In an ongoing forward genetic screen forN-ethyl-N-nitrosourea (ENU)-induced mutations that increase susceptibility to dextran sodium sulfate (DSS)-induced colitis in mice, we identified two nonsense mutations inLrba. Although Tregcells have been a main focus in LRBA research to date, we found that dendritic cells (DCs) contribute significantly to DSS-induced intestinal inflammation in LRBA-deficient mice.Lrba−/−DCs exhibited excessive IRF3/7- and PI3K/mTORC1-dependent signaling and type I IFN production in response to the stimulation of the Toll-like receptors (TLRs) 3, TLR7, and TLR9. Substantial reductions in cytokine expression and sensitivity to DSS in LRBA-deficient mice were caused by knockout ofUnc93b1, a chaperone necessary for trafficking of TLR3, TLR7, and TLR9 to endosomes. Our data support a function for LRBA in limiting endosomal TLR signaling and consequent intestinal inflammation.

scholarly journals Curcumin and Intestinal Inflammatory Diseases: Molecular Mechanisms of Protection

2019 ◽  
Vol 20 (8) ◽  
pp. 1912 ◽  
Author(s):  
Kathryn Burge ◽  
Aarthi Gunasekaran ◽  
Jeffrey Eckert ◽  
Hala Chaaban
Keyword(s):  
Molecular Mechanisms ◽  
Intestinal Inflammation ◽  
Inflammatory Diseases ◽  
Intestinal Barrier ◽  
Immunological Response ◽  
Intestinal Microbiome ◽  
Intestinal Barrier Function ◽  
Dietary Antigens ◽  
Inflammatory Bowel ◽  
Intestinal Inflammatory Disease

Intestinal inflammatory diseases, such as Crohn’s disease, ulcerative colitis, and necrotizing enterocolitis, are becoming increasingly prevalent. While knowledge of the pathogenesis of these related diseases is currently incomplete, each of these conditions is thought to involve a dysfunctional, or overstated, host immunological response to both bacteria and dietary antigens, resulting in unchecked intestinal inflammation and, often, alterations in the intestinal microbiome. This inflammation can result in an impaired intestinal barrier allowing for bacterial translocation, potentially resulting in systemic inflammation and, in severe cases, sepsis. Chronic inflammation of this nature, in the case of inflammatory bowel disease, can even spur cancer growth in the longer-term. Recent research has indicated certain natural products with anti-inflammatory properties, such as curcumin, can help tame the inflammation involved in intestinal inflammatory diseases, thus improving intestinal barrier function, and potentially, clinical outcomes. In this review, we explore the potential therapeutic properties of curcumin on intestinal inflammatory diseases, including its antimicrobial and immunomodulatory properties, as well as its potential to alter the intestinal microbiome. Curcumin may play a significant role in intestinal inflammatory disease treatment in the future, particularly as an adjuvant therapy.

scholarly journals Macrophage dysfunction initiates colitis during weaning of infant mice lacking the interleukin-10 receptor

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Naresh S Redhu ◽  
Vasudevan Bakthavatchalu ◽  
Evan A Conaway ◽  
Dror S Shouval ◽  
Amy Tsou ◽  
...  
Keyword(s):  
Infant Development ◽  
Intestinal Inflammation ◽  
Interleukin 10 ◽  
Postnatal Period ◽  
Macrophage Function ◽  
Murine Colitis ◽  
Macrophage Depletion ◽  
Macrophage Dysfunction ◽  
Inflammatory Bowel ◽  
Deficient Mice

Infants with defects in the interleukin 10 receptor (IL10R) develop very early onset inflammatory bowel disease. Whether IL10R regulates lamina propria macrophage function during infant development in mice and whether macrophage-intrinsic IL10R signaling is required to prevent colitis in infancy is unknown. Here we show that although signs of colitis are absent in IL10R-deficient mice during the first two weeks of life, intestinal inflammation and macrophage dysfunction begin during the third week of life, concomitant with weaning and accompanying diversification of the intestinal microbiota. However, IL10R did not directly regulate the microbial ecology during infant development. Interestingly, macrophage depletion with clodronate inhibited the development of colitis, while the absence of IL10R specifically on macrophages sensitized infant mice to the development of colitis. These results indicate that IL10R-mediated regulation of macrophage function during the early postnatal period is indispensable for preventing the development of murine colitis.

scholarly journals Studies on the Interleukin-10 Gene in Animal Models of Colitis

2001 ◽  
Vol 15 (8) ◽  
pp. 557-558
Author(s):  
Hugh J Freeman
Keyword(s):  
Inflammatory Bowel Disease ◽  
Animal Models ◽  
Bowel Disease ◽  
Inflammatory Process ◽  
Intestinal Inflammation ◽  
Therapeutic Potential ◽  
Interleukin 10 ◽  
Necrosis Factor Alpha ◽  
Inflammatory Bowel ◽  
Deficient Mice

Cytokines play a role in the inflammatory process in colitis and may have therapeutic potential. Interleukin-10 (IL-10) has both immunomodulatory and anti-inflammatory properties. IL-10-deficient mice develop intestinal inflammation with increased tissue levels of other cytokines, including tumour necrosis factor-alpha. In patients with inflammatory bowel disease, impaired IL-10 production by lamina propria T cells occurs and human recombinant IL-10 improves clinical parameters in inflammatory bowel disease (eg, Crohn's disease). There seem to be conflicting results in differing animal models, and the timing of administration of IL-10 relative to onset of colitis may be critical, possibly due to rapid clearance of IL-10. Interestingly, in IL-10 gene-deficient mice raised in germ-free conditions, the intestinal inflammatory changes normally observed in conventional nongerm-free conditions are not detected, suggesting a role for luminal bacteria in the pathogenesis of the inflammatory process.

scholarly journals A bacterial immunomodulatory protein with lipocalin-like domains facilitates host–bacteria mutualism in larval zebrafish

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Annah S Rolig ◽  
Emily Goers Sweeney ◽  
Lila E Kaye ◽  
Michael D DeSantis ◽  
Arden Perkins ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Intestinal Inflammation ◽  
Structural Similarity ◽  
Lipocalin 2 ◽  
Neutrophil Accumulation ◽  
Zebrafish Model ◽  
Larval Zebrafish ◽  
Chemically Induced ◽  
Immune Attack ◽  
Immunomodulatory Protein

Stable mutualism between a host and its resident bacteria requires a moderated immune response to control bacterial population size without eliciting excessive inflammation that could harm both partners. Little is known about the specific molecular mechanisms utilized by bacterial mutualists to temper their hosts’ responses and protect themselves from aggressive immune attack. Using a gnotobiotic larval zebrafish model, we identified an Aeromonas secreted immunomodulatory protein, AimA. AimA is required during colonization to prevent intestinal inflammation that simultaneously compromises both bacterial and host survival. Administration of exogenous AimA prevents excessive intestinal neutrophil accumulation and protects against septic shock in models of both bacterially and chemically induced intestinal inflammation. We determined the molecular structure of AimA, which revealed two related calycin-like domains with structural similarity to the mammalian immune modulatory protein, lipocalin-2. As a secreted bacterial protein required by both partners for optimal fitness, AimA is an exemplar bacterial mutualism factor.

II. Modulating leukocyte recruitment to splanchnic organs to reduce inflammation

2003 ◽  
Vol 284 (5) ◽  
pp. G729-G733 ◽  
Author(s):  
Claudine S. Bonder ◽  
Paul Kubes
Keyword(s):  
Chemokine Receptors ◽  
Molecular Mechanisms ◽  
Intestinal Inflammation ◽  
Cell Types ◽  
Neutrophil Recruitment ◽  
Leukocyte Recruitment ◽  
T Lymphocyte Subsets ◽  
Growing Body ◽  
Numerous Cell ◽  
Inflammatory Bowel

A hallmark feature of intestinal inflammation is the recruitment and extravasation of numerous cell types from the blood to the afflicted site. Much of what we know about the mechanisms of leukocyte recruitment to splanchnic organs comes from an extensive series of studies on neutrophils in the mesenteric microvasculature. In this themes article, we highlight the important findings from these experiments but also emphasize some of the limitations. In fact, there is a growing body of evidence that neutrophil recruitment may be quite different in the mesentery than in other splanchnic organs. For example, the molecular mechanisms underlying neutrophil recruitment into the liver are quite different than the mesentery and are dependent on the type of inflammatory disease. We also discuss the effect of modulating leukocyte recruitment to splanchnic organs in chronic inflammation and emphasize that the approaches that have been successful in acute inflammation may be less effective in such conditions as inflammatory bowel disease (IBD). One obvious reason for this observation is the growing body of evidence to suggest that the initiation and maintenance of IBD is, in part, due to dysregulated or inappropriately activated populations of infiltrating T lymphocyte subsets. Therefore, we also discuss some interesting new approaches to limiting lymphocyte recruitment into the inflamed intestine either by targeting T helper (Th)1 vs. Th2 lymphocytes or perhaps by allowing the recruitment of regulatory T cells. Inhibiting specific adhesion molecules or specific chemokine receptors may work in this regard.

scholarly journals Gasdermin D in macrophages restrains colitis by controlling cGAS-mediated inflammation

2020 ◽  
Vol 6 (21) ◽  
pp. eaaz6717 ◽  
Author(s):  
Chunmei Ma ◽  
Dongxue Yang ◽  
Bingwei Wang ◽  
Chunyan Wu ◽  
Yuqing Wu ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Cyclic Gmp ◽  
Intestinal Inflammation ◽  
Experimental Colitis ◽  
Underlying Mechanism ◽  
Negative Regulator ◽  
Chemically Induced ◽  
Mechanistic Basis ◽  
Functional Relevance ◽  
Deficient Mice

The functional relevance and mechanistic basis of the effects of the pyroptosis executioner Gasdermin D (GSDMD) on colitis remain unclear. In this study, we observed that GSDMD protein was activated during intestinal inflammation in a model of chemically induced colitis. GSDMD deficiency exacerbated experimental colitis independent of changes in the microbiota and without affecting the production of antimicrobial peptides. GSDMD deficiency in macrophages, but not epithelial cells, was sufficient to drive this exacerbated experimental colitis. We further demonstrate that GSDMD functions in macrophages as a negative regulator to control cyclic GMP–AMP synthase (cGAS)–dependent inflammation, thereby protecting against colitis. Moreover, the administration of cGAS inhibitor can rescue the colitogenic phenotype in GSDMD-deficient mice. Collectively, these findings provide the first demonstration of GSDMD’s role in controlling colitis and a detailed delineation of the underlying mechanism.

Bringing to Light the Risk of Colorectal Cancer in Inflammatory Bowel Disease: Mucosal Glycosylation as a Key Player

2021 ◽  
Author(s):  
Eduarda Leite-Gomes ◽  
Ana M Dias ◽  
Catarina M Azevedo ◽  
Beatriz Santos-Pereira ◽  
Mariana Magalhães ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Inflammatory Bowel Disease ◽  
Bowel Disease ◽  
Molecular Mechanisms ◽  
Intestinal Inflammation ◽  
Serum Proteins ◽  
Major Complication ◽  
Cancer Pathogenesis ◽  
Colon Inflammation ◽  
Inflammatory Bowel

Abstract Colitis-associated cancer is a major complication of inflammatory bowel disease remaining an important clinical challenge in terms of diagnosis, screening, and prognosis. Inflammation is a driving factor both in inflammatory bowel disease and cancer, but the mechanism underlying the transition from colon inflammation to cancer remains to be defined. Dysregulation of mucosal glycosylation has been described as a key regulatory mechanism associated both with colon inflammation and colorectal cancer development. In this review, we discuss the major molecular mechanisms of colitis-associated cancer pathogenesis, highlighting the role of glycans expressed at gut epithelial cells, at lamina propria T cells, and in serum proteins in the regulation of intestinal inflammation and its progression to colon cancer, further discussing its potential clinical and therapeutic applications.

Spi-B is critical for plasmacytoid dendritic cell function and development

Blood ◽  
2012 ◽  
Vol 120 (24) ◽  
pp. 4733-4743 ◽  
Author(s):  
Izumi Sasaki ◽  
Katsuaki Hoshino ◽  
Takahiro Sugiyama ◽  
Chihiro Yamazaki ◽  
Takahiro Yano ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Dendritic Cell ◽  
Molecular Mechanisms ◽  
Cell Function ◽  
Plasmacytoid Dendritic Cell ◽  
Cell Subset ◽  
Type I ◽  
Dendritic Cell Subset ◽  
Type I Ifn ◽  
Deficient Mice

Abstract Plasmacytoid dendritic cells (pDCs), originating from hematopoietic progenitor cells in the BM, are a unique dendritic cell subset that can produce large amounts of type I IFNs by signaling through the nucleic acid–sensing TLR7 and TLR9 (TLR7/9). The molecular mechanisms for pDC function and development remain largely unknown. In the present study, we focused on an Ets family transcription factor, Spi-B, that is highly expressed in pDCs. Spi-B could transactivate the type I IFN promoters in synergy with IFN regulatory factor 7 (IRF-7), which is an essential transcription factor for TLR7/9-induced type I IFN production in pDCs. Spi-B–deficient pDCs and mice showed defects in TLR7/9-induced type I IFN production. Furthermore, in Spi-B–deficient mice, BM pDCs were decreased and showed attenuated expression of a set of pDC-specific genes whereas peripheral pDCs were increased; this uneven distribution was likely because of defective retainment of mature nondividing pDCs in the BM. The expression pattern of cell-surface molecules in Spi-B–deficient mice indicated the involvement of Spi-B in pDC development. The developmental defects of pDCs in Spi-B–deficient mice were more prominent in the BM than in the peripheral lymphoid organs and were intrinsic to pDCs. We conclude that Spi-B plays critical roles in pDC function and development.

scholarly journals Mosaic Tetrasomy 9p Associated With Inflammatory Bowel Disease

2019 ◽  
Vol 13 (11) ◽  
pp. 1474-1478 ◽  
Author(s):  
Luis Sifuentes-Dominguez ◽  
Petro Starokadomskyy ◽  
Jacob Welch ◽  
Bhaskar Gurram ◽  
Jason Y Park ◽  
...  
Keyword(s):  
Inflammatory Bowel Disease ◽  
Bowel Disease ◽  
Intestinal Inflammation ◽  
Type I Interferon ◽  
Organ Damage ◽  
Genomic Region ◽  
Chromosome 9 ◽  
Type I ◽  
First Case ◽  
Inflammatory Bowel

Abstract The genetic basis of inflammatory bowel disease remains to be elucidated completely. Here we report on a patient with inflammatory bowel disease who has mosaic tetrasomy of the short arm of chromosome 9, a genomic region that harbours the type I interferon gene cluster. We show that increased interferon activation is present in peripheral blood and intestinal tissue from this patient, similar to previous reports of autoinflammatory organ damage driven by interferon activation in other patients with this chromosomal abnormality. To our knowledge, this is the first case of tetrasomy 9p-associated interferonopathy driving intestinal inflammation and highlights the role that type-I interferon pathways can play in the pathogenesis of intestinal inflammation.

scholarly journals Hyaluronan Synthase 3 Null Mice Exhibit Decreased Intestinal Inflammation and Tissue Damage in the DSS-Induced Colitis Model

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Sean P. Kessler ◽  
Dana R. Obery ◽  
Carol de la Motte
Keyword(s):  
Intestinal Inflammation ◽  
Inflammatory Diseases ◽  
Experimental Colitis ◽  
Hyaluronan Synthase ◽  
Wild Type ◽  
Colon Tissue ◽  
Dss Colitis ◽  
Chemically Induced ◽  
Inflammatory Bowel ◽  
Colitis Model

Hyaluronan (HA) overproduction is a hallmark of multiple inflammatory diseases, including inflammatory bowel disease (IBD). Hyaluronan can act as a leukocyte recruitment molecule and in the most common mouse model of intestinal inflammation, the chemically induced dextran sodium sulfate (DSS) experimental colitis model, we previously determined that changes in colon distribution of HA occur before inflammation. Therefore, we hypothesized that, during a pathologic challenge, HA promotes inflammation. In this study, we tested the progression of inflammation in mice null for the hyaluronan synthase genes (HAS1, HAS3, or both HAS1 and HAS3) in the DSS-colitis model. Our data demonstrate that both the HAS1/HAS3 double and the HAS3 null mice are protected from colitis, compared to wild-type and HAS1 null mice, as determined by measurement of weight loss, disease activity, serum IL-6 levels, histologic scoring, and immunohistochemistry. Most notable is the dramatic increase in submucosal microvasculature, hyaluronan deposition, and leukocyte infiltration in the inflamed colon tissue of wild-type and HAS1 null mice. Our data suggest, HAS3 plays a crucial role in driving gut inflammation. Developing a temporary targeted therapeutic intervention of HAS3 expression or function in the microcirculation may emerge as a desirable strategy toward tempering colitis in patients undergoing flares of IBD.

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