scholarly journals Pharmacological inhibition of GPR4 remediates intestinal inflammation in a mouse colitis model

2019 ◽  
Author(s):  
Edward J. Sanderlin ◽  
Mona Marie ◽  
Juraj Velcicky ◽  
Pius Loetscher ◽  
Li V. Yang
Keyword(s):  
Mouse Model ◽  
Intestinal Inflammation ◽  
Drug Effects ◽  
Body Weight Loss ◽  
Vehicle Control ◽  
Ph Sensing ◽  
Acute Colitis ◽  
Increased Risk ◽  
Disease Indicators ◽  
Vascular Adhesion

AbstractInflammatory bowel disease (IBD) is characterized by chronic, recurring inflammation of the digestive tract. Current therapeutic approaches are limited and include biologics and steroids such as anti-TNFα monoclonal antibodies and corticosteroids, respectively. Significant adverse drug effects can occur for chronic usage and include increased risk of infection in some patients. GPR4, a pH-sensing G protein-coupled receptor, has recently emerged as a potential therapeutic target for intestinal inflammation. We have assessed the effects of a GPR4 antagonist, 2-(4-((2-Ethyl-5,7-dimethylpyrazolo[1,5-a]pyrimidin-3-yl)methyl)phenyl)-5-(piperidin-4-yl)-1,3,4-oxadiazole (GPR4 antagonist 13, also known as NE 52-QQ57) in the dextran sulfate sodium (DSS)-induced acute colitis mouse model. The GPR4 antagonist 13 inhibited intestinal inflammation. The clinical parameters such as body weight loss and fecal score were reduced in the GPR4 antagonist 13 treatment group compared to vehicle control. Macroscopic disease indicators such as colon shortening, splenic expansion, and mesenteric lymph node enlargement were all reduced in severity in the GPR4 antagonist 13 treated mice. Histopathological features of active colitis were alleviated in GPR4 antagonist 13 treatment groups compared to vehicle control. Finally, inflammatory gene expression in the colon tissues and vascular adhesion molecule expression in the intestinal endothelia were attenuated by GPR4 antagonist 13. Our results indicate that GPR4 antagonist 13 provides a protective effect in the DSS-induced acute colitis mouse model, and inhibition of GPR4 can be explored as a novel anti-inflammatory approach.

scholarly journals Intestinal Inflammation and Altered Gut Microbiota Associated with Inflammatory Bowel Disease Render Mice Susceptible to Clostridioides difficile Colonization and Infection

mBio ◽  
2021 ◽  
Author(s):  
Lisa Abernathy-Close ◽  
Madeline R. Barron ◽  
James M. George ◽  
Michael G. Dieterle ◽  
Kimberly C. Vendrov ◽  
...  
Keyword(s):  
Inflammatory Bowel Disease ◽  
Mouse Model ◽  
Gut Microbiota ◽  
Intestinal Inflammation ◽  
Antibiotic Use ◽  
Content Type ◽  
Clostridioides Difficile ◽  
Increased Risk ◽  
Inflammatory Bowel ◽  
The Relationship

The incidence of C. difficile infection (CDI) has increased significantly among patients with IBD, independently of antibiotic use, yet the relationship between IBD and increased risk for CDI remains to be understood. Our study sought to describe and utilize an antibiotic-independent mouse model to specifically explore the relationship between the IBD-associated gut and susceptibility to C. difficile colonization and CDI development.

scholarly journals P033 Combination of vedolizumab with tacrolimus is more efficient in reducing intestinal inflammation than vedolizumab alone in the DSS-induced acute colitis mouse model

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S148-S148
Author(s):  
R Manzini ◽  
K Atrott ◽  
M Schwarzfischer ◽  
A Laimbacher ◽  
S Lang ◽  
...  
Keyword(s):  
T Cells ◽  
Mouse Model ◽  
Molecular Mechanisms ◽  
Immune Cell ◽  
Intestinal Inflammation ◽  
Sodium Sulphate ◽  
Intestinal Epithelial ◽  
Acute Colitis ◽  
Human Cd34 ◽  
Epithelial Cell Apoptosis

Abstract Background The humanised monoclonal antibody vedolizumab is used in the treatment of ulcerative colitis (UC) and Crohn’s disease (CD). Vedolizumab reduces intestinal inflammation through inhibition of the integrin heterodimer α 4β 7, responsible for the homing of T cells to the intestinal mucosa. Recent studies have also shown a possible involvement of vedolizumab in the regulation of the innate immune system. Particularly in CD, only a fraction of patients respond to vedolizumab treatment, and combination therapy with immunosuppressant drugs, such as the calcineurin-inhibitor tacrolimus, might prove beneficial. The aim of this study was to assess if co-treatment of vedolizumab and tacrolimus is more efficient in reducing intestinal inflammation in an acute colitis mouse model and to unravel the underlying molecular mechanisms. Methods NOD-SCID-SGM3 mice were reconstituted with human CD34+ cells and treated with 3% dextrane sodium sulphate (DSS) in drinking water to induce acute colitis. Mice were treated with vedolizumab alone (30mg/kg, inject 3 days prior to DSS-start and 50mg/kg at day 0 and at day 4 of DSS-treatment), tacrolimus alone (1mg/kg/day intraperitoneally), or a combination of tacrolimus and vedolizumab during colitis induction. Results As expected, DSS-treatment induced colitis in mice as observed by weight loss, diarrhoea, colon shortening, and endoscopic signs of inflammation categorised by the MEICS score. This translated histologically to an increased immune cell infiltration and epithelial erosion. Vedolizumab and tacrolimus treatment alone did not significantly reduce colitis severity, although endoscopy showed slightly less severe inflammation in vedolizumab-treated mice. Combination of vedolizumab and tacrolimus, however, clearly reduced colonoscopy and histology scores. DSS-treatment increased the number of CD3 T cells and CD68 macrophages in the intestine, an effect counteracted by vedolizumab or tacrolimus alone and further pronounced by combination treatment. Particularly vedolizumab treatment, either alone or in combination, caused clear reduction of pro-inflammatory M1 macrophages. Additionally, vedolizumab alone or combined decreased the levels of intestinal epithelial cell apoptosis as indicated by staining for cleaved caspase-3. Conclusion Our data demonstrate that the anti-inflammatory effect of vedolizumab is potentiated by co-treatment with tacrolimus. Notably, the combination of both drugs was more efficient in reducing T-cell and macrophage infiltration into the intestine. This indicates that the combination of vedolizumab with immunosuppressant drugs might prove beneficial for patients that do not respond to vedolizumab-only therapy.

scholarly journals Inhibition of TLR4 Signaling Impedes Tumor Growth in Colitis-Associated Colon Cancer

2021 ◽  
Vol 12 ◽  
Author(s):  
Eva Pastille ◽  
Tabea Faßnacht ◽  
Alexandra Adamczyk ◽  
Nhi Ngo Thi Phuong ◽  
Jan Buer ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Tumor Growth ◽  
Pathogenic Bacteria ◽  
Intestinal Inflammation ◽  
Specific Inhibitor ◽  
Body Weight Loss ◽  
Tlr4 Signaling ◽  
Novel Approach ◽  
Increased Risk ◽  
The Impact

Patients suffering from ulcerative colitis are at increased risk of developing colorectal cancer. Although the exact underlying mechanisms of inflammation-associated carcinogenesis remain unknown, the intestinal microbiota as well as pathogenic bacteria are discussed as contributors to inflammation and colitis-associated colon cancer (CAC). In the present study, we analyzed the impact of TLR4, the receptor for Gram-negative bacteria derived lipopolysaccharides, on intestinal inflammation and tumorigenesis in a murine model of CAC. During the inflammatory phases of CAC development, we observed a strong upregulation of Tlr4 expression in colonic tissues. Blocking of TLR4 signaling by a small-molecule-specific inhibitor during the inflammatory phases of CAC strongly diminished the development and progression of colonic tumors, which was accompanied by decreased numbers of infiltrating macrophages and reduced colonic pro-inflammatory cytokine levels compared to CAC control mice. Interestingly, inhibiting bacterial signaling by antibiotic treatment during the inflammatory phases of CAC also protected mice from severe intestinal inflammation and almost completely prevented tumor growth. Nevertheless, application of antibiotics involved rapid and severe body weight loss and might have unwanted side effects. Our results indicate that bacterial activation of TLR4 on innate immune cells in the colon triggers inflammation and promotes tumor growth. Thus, the inhibition of the TLR4 signaling during intestinal inflammation might be a novel approach to impede CAC development.

scholarly journals A Novel OGR1 (GPR68) Inhibitor Attenuates Inflammation in Murine Models of Colitis

2021 ◽  
pp. 1-14
Author(s):  
Cheryl de Vallière ◽  
Katharina Bäbler ◽  
Philipp Busenhart ◽  
Marlene Schwarzfischer ◽  
Chiaki Maeyashiki ◽  
...  
Keyword(s):  
Small Molecule ◽  
Cellular Proliferation ◽  
Immune Cell ◽  
Intestinal Inflammation ◽  
Ph Sensing ◽  
Murine Models ◽  
Ki 67 ◽  
Murine Colitis ◽  
Disease Indicators ◽  
Fibrosis Marker

<b><i>Background and Aims:</i></b> Local extracellular acidification is associated with several conditions, such as ischemia, cancer, metabolic disease, respiratory diseases, and inflammatory bowel disease (IBD). Several recent studies reported a link between IBD and a family of pH-sensing G protein-coupled receptors. Our previous studies point to an essential role for OGR1 (GPR68) in the modulation of intestinal inflammation and fibrosis. In the current study, we evaluated the effects of a novel OGR1 inhibitor in murine models of colitis. <b><i>Methods:</i></b> The effects of a novel small-molecule OGR1 inhibitor were assessed in the acute and chronic dextran sulfate sodium (DSS) murine models of colitis. Macroscopic disease indicators of intestinal inflammation were evaluated, and epithelial damage and immune cell infiltration and proliferation were assessed by immunohistochemistry. <b><i>Results:</i></b> The OGR1 inhibitor ameliorated clinical parameters in acute and chronic DSS-induced colitis. In mice treated with the OGR1 inhibitor, endoscopy showed no thickening and normal vascularity, while fibrin was not detected. Histopathological findings revealed a decrease in severity of colonic inflammation in the OGR1 inhibitor group when compared to vehicle-DSS controls. In OGR1 inhibitor-treated mice, staining for the macrophage marker F4/80 and cellular proliferation marker Ki-67 revealed a reduction of infiltrating macrophages and slightly enhanced cell proliferation, respectively. This was accompanied by a reduction in pro-inflammatory cytokines, TNF and IL-6, and the fibrosis marker TGF-β1. <b><i>Conclusion:</i></b> This is the first report providing evidence that a pharmacological inhibition of OGR1 has a therapeutic effect in murine colitis models. Our data suggest that targeting proton-sensing OGR1 using specific small-molecule inhibitors may be a novel therapeutic approach for the treatment of IBD.

scholarly journals Characterization of the Synergistic Effect between Ligands of Opioid and Free Fatty Acid Receptors in the Mouse Model of Colitis

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6827
Author(s):  
Agata Binienda ◽  
Adam Makaro ◽  
Marcin Talar ◽  
Julia B. Krajewska ◽  
Aleksandra Tarasiuk ◽  
...  
Keyword(s):  
Mouse Model ◽  
Synergistic Effect ◽  
Immune Cells ◽  
Dextran Sulfate ◽  
Dextran Sulfate Sodium ◽  
Intestinal Inflammation ◽  
Acute Colitis ◽  
Μ Opioid Receptor ◽  
Free Fatty Acid Receptors

Background: Recent studies suggest that lipids, including free fatty acids (FFAs), are necessary for proper μ opioid receptor (MOR) binding and that activation of opioid receptors (ORs) improves intestinal inflammation. The objective of the study was to investigate a possible interaction between the ORs and FFA receptors (FFARs) ligands in the colitis. Methods: The potential synergistic effect of ORs and FFARs ligands was evaluated using mouse model of acute colitis induced by dextran sulfate sodium (DSS, 4%). Compounds were injected intraperitoneally (i.p.) once or twice daily at the doses of 0.01 or 0.02 mg/kg body weight (BW) (DAMGO—an MOR agonist), 0.3 mg/kg BW (DPDPE—a δ OR (DOR) agonist) and 1 mg/kg BW (naloxone—a non-selective OR antagonist, GLPG 0974—a FFAR2 antagonist, GSK 137647—a FFAR4 agonist and AH 7614—a FFAR4 antagonist) for 4 days. Results: Myeloperoxidase (MPO) activity was significantly decreased after DAMGO (0.02 mg/kg BW) and GSK 137647 (1 mg/kg BW) administration and co-administration as compared to DSS group. Conclusions: Treatment with ligands of ORs and FFARs may affect the immune cells in the inflammation; however, no significant influence on the severity of colitis and no synergistic effect were observed.

scholarly journals A probiotic complex, rosavin, zinc, and prebiotics ameliorate intestinal inflammation in an acute colitis mouse model

2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Jin-Sil Park ◽  
JeongWon Choi ◽  
Ji Ye Kwon ◽  
Kyung-Ah Jung ◽  
Chul Woo Yang ◽  
...  
Keyword(s):  
Mouse Model ◽  
Intestinal Inflammation ◽  
Acute Colitis

scholarly journals The Capsule Encoding the viaB Locus Reduces Interleukin-17 Expression and Mucosal Innate Responses in the Bovine Intestinal Mucosa during Infection with Salmonella enterica Serotype Typhi

2007 ◽  
Vol 75 (9) ◽  
pp. 4342-4350 ◽  
Author(s):  
Manuela Raffatellu ◽  
Renato L. Santos ◽  
Daniela Chessa ◽  
R. Paul Wilson ◽  
Sebastian E. Winter ◽  
...  
Keyword(s):  
Mouse Model ◽  
Salmonella Enterica ◽  
Intestinal Inflammation ◽  
Fluid Secretion ◽  
Interleukin 17 ◽  
Loop Model ◽  
Wild Type ◽  
Ileal Loop ◽  
Chemokine Production

ABSTRACT The viaB locus contains genes for the biosynthesis and export of the Vi capsular antigen of Salmonella enterica serotype Typhi. Wild-type serotype Typhi induces less CXC chemokine production in tissue culture models than does an isogenic viaB mutant. Here we investigated the in vivo relevance of these observations by determining whether the presence of the viaB region prevents inflammation in two animal models of gastroenteritis. Unlike S. enterica serotype Typhimurium, serotype Typhi or a serotype Typhi viaB mutant did not elicit marked inflammatory changes in the streptomycin-pretreated mouse model. In contrast, infection of bovine ligated ileal loops with a serotype Typhi viaB mutant resulted in more fluid accumulation and higher expression of the chemokine growth-related oncogene alpha (GROα) and interleukin-17 (IL-17) than did infection with the serotype Typhi wild type. There was a marked upregulation of IL-17 expression in both the bovine ligated ileal loop model and the streptomycin-pretreated mouse model, suggesting that this cytokine is an important component of the inflammatory response to infection with Salmonella serotypes. Introduction of the cloned viaB region into serotype Typhimurium resulted in a significant reduction of GROα and IL-17 expression and in reduced fluid secretion. Our data support the idea that the viaB region plays a role in reducing intestinal inflammation in vivo.

scholarly journals Acute small intestinal inflammation results in persistent lymphatic alterations

2018 ◽  
Vol 314 (3) ◽  
pp. G408-G417 ◽  
Author(s):  
Sonia Rehal ◽  
Matthew Stephens ◽  
Simon Roizes ◽  
Shan Liao ◽  
Pierre-Yves von der Weid
Keyword(s):  
Dendritic Cell ◽  
Lymphatic System ◽  
Intestinal Inflammation ◽  
Critical Role ◽  
Lymphatic Vessels ◽  
Lymphoid Tissues ◽  
Functional Changes ◽  
Increased Risk ◽  
Small Intestinal ◽  
Acute Ileitis

Inflammatory bowel disease (IBD) has a complex pathophysiology with limited treatments. Structural and functional changes in the intestinal lymphatic system have been associated with the disease, with increased risk of IBD occurrence linked to a history of acute intestinal injury. To examine the potential role of the lymphatic system in inflammation recurrence, we evaluated morphological and functional changes in mouse mucosal and mesenteric lymphatic vessels, and within the mesenteric lymph nodes during acute ileitis caused by a 7-day treatment with dextran sodium sulfate (DSS). We monitored whether the changes persisted during a 14-day recovery period and determined their potential consequences on dendritic cell (DC) trafficking between the mucosa and lymphoid tissues. DSS administration was associated with marked lymphatic abnormalities and dysfunctions exemplified by lymphangiectasia and lymphangiogenesis in the ileal mucosa and mesentery, increased mesenteric lymphatic vessel leakage, and lymphadenopathy. Lymphangiogenesis and lymphadenopathy were still evident after recovery from intestinal inflammation and correlated with higher numbers of DCs in mucosal and lymphatic tissues. Specifically, a deficit in CD103+ DCs observed during acute DSS in the lamina propria was reversed and further enhanced during recovery. We concluded that an acute intestinal insult caused alterations of the mesenteric lymphatic system, including lymphangiogenesis, which persisted after resolution of inflammation. These morphological and functional changes could compromise DC function and movement, increasing susceptibility to further gastrointestinal disease. Elucidation of the changes in mesenteric and intestinal lymphatic function should offer key insights for new therapeutic strategies in gastrointestinal disorders such as IBD. NEW & NOTEWORTHY Lymphatic integrity plays a critical role in small intestinal homeostasis. Acute intestinal insult in a mouse model of acute ileitis causes morphological and functional changes in mesenteric and intestinal lymphatic vessels. While some of the changes significantly regressed during inflammation resolution, others persisted, including lymphangiogenesis and altered dendritic cell function and movement, potentially increasing susceptibility to the recurrence of gastrointestinal inflammation.

Abstract TP256: Mouse Model of Uremic Cerebral Microbleeds

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Wei Ling Lau ◽  
Mary Tarbiat-Boldaji ◽  
Hayley Smalls ◽  
Ane Nunes ◽  
Javad Savoj ◽  
...  
Keyword(s):  
Mouse Model ◽  
Tight Junction ◽  
Blood Brain Barrier ◽  
Cerebral Microbleeds ◽  
Brain Barrier ◽  
Barrier Integrity ◽  
Blood Brain ◽  
Increased Risk ◽  
Junction Protein ◽  
Blood Brain Barrier Integrity

Introduction: Cerebral microbleeds are more common in chronic kidney disease (CKD) and dialysis patients compared to the general population. Diminished kidney function alone appears to be a risk factor for microbleeds, independent of age and hypertension. Microbleed burden in CKD patients is associated with increased risk of future hemorrhagic stroke and with cognitive dysfunction. The mechanisms that drive uremic microbleed formation are unclear. Hypothesis: We hypothesized that CKD mice are predisposed to develop cerebral microhemorrhages (the pathologic substrate of microbleeds), and that a standardized inflammatory stimulus (lipopolysaccharide, LPS) will amplify microhemorrhage burden in CKD mice compared to non-CKD controls (CTL). We also hypothesized that uremia induces depletion of tight junction proteins, altering blood-brain barrier integrity and representing a potential mechanism of microbleed formation. Methods: Animal groups included CTL (n=3), CKD (n=3), CTL+LPS (n=5) and CKD+LPS (n=5). CKD induction in male C57BL/6 mice was achieved via nephrotoxic adenine diet x18 days. Two weeks following CKD induction, CKD and control mice were treated with LPS 1 mg/kg i.p. dosed at 0, 6 and 24 hours. Brains were harvested one week after LPS injections and 40-micron sections were stained using Prussian blue to identify microhemorrhages. Immunohistochemistry was performed for the blood-brain barrier tight junction protein claudin-5. Results: CKD mice had significantly elevated blood urea nitrogen, and tubulointerstitial fibrosis was present on kidney histology. Total number of microhemorrhages per brain was 2.3±1.5 (mean ± standard error of the mean) for CTL mice, 8.3±1.5 for CKD mice, 23.2±4.2 for CTL+LPS mice, and 27.6±6.2 for CKD+LPS mice (p<0.05 for CKD+LPS vs. CTL). Immunostaining showed decreased claudin-5 expression in CKD mice compared to CTL. Conclusions: We have generated a mouse model that will facilitate future mechanistic studies in the field of uremic microbleeds. Our initial findings suggest that CKD alters blood-brain barrier integrity and that inflammation amplifies development of microbleeds in CKD.

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