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Lee J, Szczepanski HE, Flannigan KL, Hirota SA. A20 INTESTINAL SMOOTH MUSCLE AND FIBROSTENOSIS: TARGETING NR4A1 TO MODULATE PROLIFERATIVE SIGNALLING. J Can Assoc Gastroenterol 2022. [PMCID: PMC8859356 DOI: 10.1093/jcag/gwab049.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Background Fibrostenotic Crohn’s Disease (CD), presenting with intestinal fibrosis and stricture formation, has a substantial impact on patient quality of life. Given our poor understanding of its etiology, we lack viable preventative and therapeutic methods. While much focus has been on the fibrotic component, recent studies have implicated the role of intestinal smooth muscle cell (SMC) hyperplasia/hypertrophy in stricture formation. These data suggest targeting SMC proliferation may provide benefit for fibrostenotic CD patients. NR4A1 (nuclear receptor subfamily 4 group A member 1) is an orphan nuclear receptor that has shown to regulate inflammation in experimental models of colitis and dampen SMC proliferation and fibrotic signalling in intestinal and non-intestinal systems. Thus, we sought to characterize the role of NR4A1 in regulating proliferative signalling in intestinal SMCs to determine whether it could be a therapeutic target for fibrostenotic CD. Aims To determine how NR4A1 regulates intestinal SMC proliferative responses to mitogenic signalling. Methods Primary intestinal SMCs were isolated from the colonic tissue of Nr4a1+/+ and Nr4a1-/- mice. A commercially available human colonic SMC line was also used. EdU incorporation assays were used to quantify the relative proliferation of Nr4a1+/+ and Nr4a1-/- SMCs in their basal or stimulated state (with platelet-derived growth factor (PDGF)-BB). In addition, NR4A1 was activated using selective agonists, cytosporone-B (Csn-B) and 6-mercaptopurine (6-MP). Differences in PDGF-BB-induced intracellular signalling was determined using western blotting of phosphorylated proteins after stimulation. Quantification of PDGF receptor transcript expression in Nr4a1+/+ and Nr4a1-/- SMCs was done using qPCR. Finally, immunofluorescence was used to determine the localization of NR4A1 when stimulated with Csn-B, 6-MP, and/or PDGF-BB. Results The proliferation assays showed that Nr4a1-/- SMCs exhibit greater proliferation at baseline and when stimulated with PDGF-BB, compared to Nr4a1+/+ SMCs. However, this was not associated with any differences in the intracellular signalling directly downstream of PDGF receptor activation. Specifically, there were no differences in the intensity and temporal characteristics of Akt- and Erk1/2-phosphorylation between Nr4a1+/+ and Nr4a1-/- SMCs. Interestingly, Nr4a1-/- SMCs had less expression of Pdgfrb, the gene encoding PDGF receptor beta, when compared to Nr4a1+/+ SMCs. However, no changes in receptor expression were observed when SMCs were stimulated with Csn-B and 6-MP. Conclusions We show that NR4A1 regulates basal and PDGF-BB-induced SMC proliferation, without directly altering the intracellular signalling cascades induced by receptor activation. Our data supports NR4A1 as a target to control the aberrant SMC proliferation that contributes to fibrostenosis. Funding Agencies CIHR
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Affiliation(s)
- J Lee
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - H E Szczepanski
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | | | - S A Hirota
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
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2
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Flannigan KL, Serra A, Hirota SA. A12 STEPWISE COORDINATION OF COLONIC NEUTROPHILS AND INNATE LYMPHOID CELLS IN THE ONSET AND RESOLUTION OF CLOSTRIDIOIDES DIFFICILE TOXIN-INDUCED INJURY. J Can Assoc Gastroenterol 2022. [PMCID: PMC8859309 DOI: 10.1093/jcag/gwab049.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background While our understanding and use of treatments for Clostridioides difficile infection (CDI) has improved, initial CDI still carries significant morbidity and mortality owing to heterogeneity in host immune responses. Further, host immunity is a critical modulator of fecal microbiota transplantation (FMT) success in CDI. Thus, understanding the host immune response during CDI is essential. Aims To assess the cellular immune responses that trigger the onset and resolution of injury and inflammation in CDI. Methods Colonic injury and inflammation triggered by CDI was modelled in mice using intrarectal installation of C. difficile toxins A and B (TcdA/B). Colonic tissue was collected at various timepoints following TcdA/B exposure to assess gene expression (qPCR), cytokine production (ELISA) and immune cell responses (flow cytometry). Knockout mice and neutralizing antibodies were used to deplete cytokines or cells. Results Examinion of colonic gene expression at different times following TcdA/B exposure found a dominant transcriptional signature related to neutrophil adhesion and diapedesis. In addition to the typical neutrophil chemokines Cxcl1 and Cxcl2, TcdA/B exposure also increased expression of neutrophil effector genes including Elane (neutrophil elastase). Neutrophil influx in response to TcdA/B was a critical driver of intestinal injury as antibody-mediated depletion of neutrophils lead to significantly less damage in the colon following TcdA/B exposure. Along with neutrophil influx, there were high levels of antimicrobial gene expression in the colon after TcdA/B exposure including RegIIIγ, S100a8, and Socs3, all genes regulated by IL-22. Upon further investigation, IL-22 was a significant mediator in the host response to TcdA/B exposure as it was upregulated >150-fold in the colon and originated from type 3 innate lymphoid cells (ILC3). Further, TcdA/B exposure in IL-22-/- mice lead to significantly more colonic damage compared to wildtype (WT) mice. Subsequent screening of previously published RNAseq data from IL-22-treated mouse colonic organoids identified various upregulated proteins involved in immune regulation, including the gene Slpi that encodes a protein (secretory leukocyte peptidase inhibitor) that inhibits leukocyte proteases, including neutrophil elastase. While TcdA/B challenge robustly induced the expression of Slpi in the colon of WT mice, IL-22-/- mice failed to express increased levels of Slpi and had greater levels of neutrophil elastase activity in the colon. Conclusions Together these data suggest a stepwise immune response to TcdA/B where ILC3 produce IL-22 to induce epithelial release of SLPI that attenuates the damaging effects of early neutrophil responses. Strategies to upregulate IL-22 may help control damage triggered by CDI and promote resolution of injury. Funding Agencies Lloyd Sutherland Chair in GI Research, Canadian Research Chair
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Affiliation(s)
- K L Flannigan
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
| | - A Serra
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
| | - S A Hirota
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
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Nieves K, Flannigan KL, Alston L, Thomson C, McCoy K, Mani S, Hirota SA. A36 THE ROLE OF MICROBIAL INDOLE METABOLITES IN CONTROLLING INFLAMMATORY RESPONSES AND HEALING IN RESPONSE TO DSS-INDUCED COLITIS. J Can Assoc Gastroenterol 2020. [DOI: 10.1093/jcag/gwz047.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Failure to resolve inflammation is often associate with the complications of Crohn’s Disease (CD). The pregnane X receptor (PXR), a xenobiotic receptor, is recognized for its role in suppressing inflammation and has recently been shown to influence fibrogenesis in the liver. In the intestine, PXR-signaling can be influenced by the microbial tryptophan metabolite indole-3- propionic acid (IPA), which can modulate intestinal inflammation, in turn influencing fibrogenesis, resolution and healing. This suggests that the gut microbiota could modulate mucosal homeostasis and resolution of inflammation via microbial metabolites
Aims
To understand and characterize the interplay between microbial complexity and the regulation of host inflammatory and healing responses, specifically focusing on the PXR and its microbial metabolite ligand IPA.
Methods
Intestinal inflammation was induced using DSS (1%, 1.5%, 2% and 3.5%) for 5 days followed by healing for 25 days in C57Bl/6 stably derived moderately diverse mouse microbiota 2 (sDMDMm2) colonized gnotobiotic and C57Bl/6 specific pathogen free (SPF) mice. Inflammation, architectural changes and fibrosis were assessed using Haemotoxylin and Eosin and Masson-Trichrome histological stains. Weight was recorded daily for the first 10 days and every other day after for 25 days, for a total of 30 days. Fecal lipocalin was quantified in samples collected throughout the study to assess inflammation. Innate immune cell influx was measured by flow cytometry, and the microbiota assessed via 16S rRNA sequencing.
Results
The gnotobiotic sDMDMm2 mice were exquisitely sensitive to DSS-induced colitis, exhibiting significantly increased mortality and morbidity at 2% and 3.5% w/v DSS compared to the SPF group. To elicit the same degree of disease to assess recovery, sDMDMm2 mice were exposed to 1.5% DSS and SPF mice to 3.5% DSS. Following 25 days recovery, sDMDMm2 colonized mice showed increased levels of fecal lipocalin 2, as compared to the SPF mice. DSS-treated sDMDMm2 mice supplemented with IPA during their recovery presented lower levels of fecal lipocalin, similar to colitic SPF mice. IPA supplemented sDMDMm2 mice also exhibited greater overall survival, with no significant differences in neutrophil count compared to mice given H20 during recovery.
Conclusions
A model system with a less complex microbiota (sDMDMm2) has a higher susceptibility to acute inflammation and a diminished capacity to resolve said inflammation. Addition of the microbial metabolite IPA normalized the recovery of the sDMDMm2 colonized mice, to a response indistinguishable from SPF mice, while also increasing survival. These data highlight the importance of microbial complexity in the regulation of intestinal mucosal homeostasis.
Funding Agencies
CAG, CCC, CIHR
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Affiliation(s)
- K Nieves
- Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | | | - L Alston
- Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - C Thomson
- Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - K McCoy
- University of Calgary, Calgary, AB, Canada
| | - S Mani
- Albert Einstein College of Medicine, The Bronx, NY
| | - S A Hirota
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
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Flannigan KL, Johnston M, Erickson SL, Nieves K, Jijon H, Gallo M, McCoy K, Hirota SA. A14 GUT-RESIDING BACTERIA CAN SHAPE HOST DRUG METABOLISM IN THE SMALL INTESTINE THROUGH AN INNATE LYMPHOID CELL-IL-22 DRIVEN AXIS. J Can Assoc Gastroenterol 2020. [DOI: 10.1093/jcag/gwz047.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
The ability of the intestinal microbiota to influence drug metabolism has been recognized, however the mechanisms through which this occurs remain unexplored. Recent work in germ-free mice showed that conventionalization with specific pathogen free (SPF) microbiota influences the expression of cytochrome P450 (CYP) enzymes in the liver and small intestine (SI), two important sites of drug metabolism. Given that CYP enzymes, including CYP3A11 in mice, account for roughly 70% of total drug metabolism, we hypothesized that commensal gut bacteria can shape the CYP landscape to influence drug metabolism and therapeutic outcomes.
Aims
To investigate the role of specific gut-residing microbes in shaping the expression and activity of host drug metabolism enzymes.
Methods
Segmented filamentous bacteria (SFB)-free mice were obtained from Jackson Lab (Jax) and colonized with feces from SFB-mono-associated mice via oral gavage. 14 days later, expression of drug metabolism enzymes in the SI were probed using PCR arrays, and lamina propria cells isolated for flow cytometry. A monoclonal antibody for Thy1.2 was used to deplete innate lymphoid cells (ILCs) in RAG1-/- mice (lacking T- and B-cells). CYP3A11 activity was determined through the colorimetric breakdown of the CYP3A11-specific substrate 7-benzyloxyresorufin. SI organoids were generated from mice and humans, and treated with IL-22 to further assess the dynamics of CYP3A11/CYP3A4 expression and activity.
Results
Colonization of Jax mice with immunomodulatory SFB altered the expression of various CYP enzymes in the SI (but not liver), with Cyp3a11 being the most downregulated gene. Further analysis showed that SFB-induced IL-22 production by type 3 ILCs (ILC3) correlated with reduced SI Cyp3a11 expression. Additionally, SFB colonization had no effect on the expression of Cyp3a11 in the SI of mice in which ILCs were depleted. Both SFB colonization and administration of IL-23, to induce IL-22 from ILC3, increased the ability of the CYP3A11-metabolized drug glyburide to decrease blood glucose levels when given orally. In mouse SI enteroid cultures, IL-22 dose-dependently reduced the expression of Cyp3a11 and decreased the ability of enteroids to metabolize CYP3A11-specific substrates. Finally, IL-22 induced wide changes in the transcriptome of human SI enteroids, with substantial effects on a drug metabolism pathway centred around CYP3A.
Conclusions
Our data suggest that a gut-resident microbe (SFB) can influence the expression and activity of the drug metabolising enzyme CYP3A11 in the SI through an ILC3-IL-22 dependent mechanism. These findings provide an understanding of how the intestinal microbiota may modulate host drug metabolism to influence the efficacy and toxicity of various pharmaceutical compounds.
Funding Agencies
CAG, CIHRAbbvie, Lloyd Sutherland Investigatorship
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Affiliation(s)
| | - M Johnston
- University of Calgary, Calgary, AB, Canada
| | - S L Erickson
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
| | - K Nieves
- Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - H Jijon
- University of Calgary, Calgary, AB, Canada
| | - M Gallo
- University of Calgary, Calgary, AB, Canada
| | - K McCoy
- University of Calgary, Calgary, AB, Canada
| | - S A Hirota
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
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Erickson SL, Flannigan KL, Alston L, Hirota SA. A209 XENOBIOTIC RECEPTOR REGULATION OF CLOSTRIDIUM DIFFICILE-ASSOCIATED TISSUE DAMAGE AND INFLAMMATION. J Can Assoc Gastroenterol 2018. [DOI: 10.1093/jcag/gwy008.210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- S L Erickson
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
| | - K L Flannigan
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
| | - L Alston
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
| | - S A Hirota
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
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6
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Flannigan KL, Alston L, Mani S, Hirota SA. A119 THE MICROBIAL METABOLITE SENSOR PREGNANE X RECEPTOR (PXR) RESTRAINS FIBROBLASTS FROM PROMOTING INTESTINAL INFLAMMATION AND FIBROSIS IN MICE. J Can Assoc Gastroenterol 2018. [DOI: 10.1093/jcag/gwy008.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- K L Flannigan
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
| | - L Alston
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
| | - S Mani
- Albert Einstein College of Medicine, Bronx, NY
| | - S A Hirota
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
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7
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Flannigan KL, Nieves KM, Erickson SL, Alston L, Hirota SA. A275 COMMENSAL BACTERIA IN THE SMALL INTESTINE INFLUENCE IMMUNE CELLS TO DICTATE HOST DRUG METABOLISM. J Can Assoc Gastroenterol 2018. [DOI: 10.1093/jcag/gwy009.275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - K M Nieves
- University of Calgary, Calgary, AB, Canada
| | - S L Erickson
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
| | - L Alston
- University of Calgary, Calgary, AB, Canada
| | - S A Hirota
- Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
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8
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Flannigan KL, Ngo VL, Geem D, Harusato A, Hirota SA, Parkos CA, Lukacs NW, Nusrat A, Gaboriau-Routhiau V, Cerf-Bensussan N, Gewirtz AT, Denning TL. IL-17A-mediated neutrophil recruitment limits expansion of segmented filamentous bacteria. Mucosal Immunol 2017; 10:673-684. [PMID: 27624780 PMCID: PMC5350071 DOI: 10.1038/mi.2016.80] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 07/05/2016] [Indexed: 02/04/2023]
Abstract
Specific components of the intestinal microbiota are capable of influencing immune responses such that a mutualistic relationship is established. In mice, colonization with segmented filamentous bacteria (SFB) induces T-helper-17 (Th17) cell differentiation in the intestine, yet the effector functions of interleukin (IL)-17A in response to SFB remain incompletely understood. Here we report that colonization of mice with SFB-containing microbiota induced IL-17A- and CXCR2-dependent recruitment of neutrophils to the ileum. This response required adaptive immunity, as Rag-deficient mice colonized with SFB-containing microbiota failed to induce IL-17A, CXCL1 and CXCL2, and displayed defective neutrophil recruitment to the ileum. Interestingly, neutrophil depletion in wild-type mice resulted in significantly augmented Th17 responses and SFB expansion, which correlated with impaired expression of IL-22 and antimicrobial peptides. These data provide novel insight into a dynamic IL-17A-CXCR2-neutrophil axis during acute SFB colonization and demonstrate a central role for neutrophils in limiting SFB expansion.
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Affiliation(s)
- K L Flannigan
- Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, USA
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - V L Ngo
- Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, USA
| | - D Geem
- Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, USA
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, USA
| | - A Harusato
- Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, USA
| | - S A Hirota
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - C A Parkos
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA
| | - N W Lukacs
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA
| | - A Nusrat
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA
| | - V Gaboriau-Routhiau
- INSERM, U1163, Laboratory of Intestinal Immunity, Université Paris Descartes-Sorbonne Paris Cité and Institut Imagine, Paris, France
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - N Cerf-Bensussan
- INSERM, U1163, Laboratory of Intestinal Immunity, Université Paris Descartes-Sorbonne Paris Cité and Institut Imagine, Paris, France
| | - A T Gewirtz
- Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, USA
| | - T L Denning
- Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, USA
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9
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Wallace JL, Flannigan KL, McKnight W, Wang L, Ferraz JGP, Tuitt D. Pro-resolution, protective and anti-nociceptive effects of a cannabis extract in the rat gastrointestinal tract. J Physiol Pharmacol 2013; 64:167-175. [PMID: 23756391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 04/17/2013] [Indexed: 06/02/2023]
Abstract
Cannabis is widely used for treating a number of gastrointestinal ailments, but its use is associated with several adverse effects, particularly when the route of administration is via smoking. In the present study, we tested the effects (in rats) of a simple extract of medicinal cannabis (called "MFF") for its ability to promote resolution of colitis, to prevent gastric damage induced by naproxen, and to reduce gastric distention-induced visceral pain. Intracolonic, but not oral administration of MFF dose-dependently reduced the severity of hapten-induced colitis, an effect not reduced by pretreatment with antagonists of CB1 or CB2 receptors. Significant improvement of symptoms (diarrhea, weight loss) and healing of ulcerated tissue was evident with MFF treatment at doses that did not produce detectable urinary levels of 9-Δ-tetrahydrocannabinol (THC). MFF increased colonic hydrogen sulfide synthesis in healthy rats, but not in rats with colitis, and had no effect on colonic prostaglandin E2 synthesis. Orally, but not systemically administered MFF dose-dependently reduced the severity of naproxen-induced gastric damage, and a CB1 antagonist reversed this effect. MFF prevented gastric distention-induced visceral pain via a CB2-dependent mechanism. These results demonstrate that a simple extract of medicinal cannabis can significantly enhance resolution of inflammation and injury, as well as prevent injury, in the gastrointestinal tract. Interestingly, different cannabinoid receptors were involved in some of the effects. MFF may serve as the basis for a simple preparation of cannabis that would produce beneficial effects in the GI tract with reduced systemic toxicity.
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MESH Headings
- Analgesics/administration & dosage
- Animals
- Anti-Inflammatory Agents, Non-Steroidal/administration & dosage
- Anti-Inflammatory Agents, Non-Steroidal/adverse effects
- Cannabis
- Colitis/drug therapy
- Colitis/metabolism
- Colitis/pathology
- Gastrointestinal Tract/drug effects
- Hydrogen Sulfide/metabolism
- Indoles/pharmacology
- Male
- Naproxen/adverse effects
- Piperidines/pharmacology
- Plant Extracts/administration & dosage
- Protective Agents/administration & dosage
- Pyrazoles/pharmacology
- Rats
- Rats, Wistar
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/antagonists & inhibitors
- Receptor, Cannabinoid, CB2/metabolism
- Stomach Ulcer/chemically induced
- Stomach Ulcer/drug therapy
- Stomach Ulcer/metabolism
- Visceral Pain/drug therapy
- Visceral Pain/metabolism
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Affiliation(s)
- J L Wallace
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada.
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10
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Elsheikh W, Flannigan KL, McKnight W, Ferraz JGP, Wallace JL. Dextran sulfate sodium induces pan-gastroenteritis in rodents: implications for studies of colitis. J Physiol Pharmacol 2012; 63:463-469. [PMID: 23211300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 09/29/2012] [Indexed: 06/01/2023]
Abstract
Dextran sulfate sodium is widely used to induce colitis in rodents. Though given orally in drinking water, this agent is widely believed to produce injury through direct toxic effects on the epithelium, and it has been assumed to produce damage and inflammation only in the colon. Given the apparent toxic effects of dextran sodium sulfate on epithelial cells, its administration orally, and the anticoagulant properties of this agent, we hypothesized that significant damage and inflammation would be produced in regions of the digestive tract proximal to the colon. Groups of rats or mice received DSS (5%) in the drinking water for up to 7 days. Tissues were harvested at various time-points for blind evaluation of damage, and measurement of several markers of inflammation. In both rats and mice given DSS, significant damage and inflammation was produced in the stomach, small intestine and colon. Significant granulocyte infiltration was apparent in all tissues by day 3 of DSS ingestion. Bleeding was evident throughout the small intestine and colon. These studies clearly demonstrate that DSS, when administered orally in drinking water, produces a pan-gastroenteritis, rather than the damage and inflammation being limited to the colon. The damage and inflammation in the stomach and small intestine could contribute to changes in body weight, stool consistency and bleeding, all of which are commonly used as indices of severity of colitis. Beneficial or detrimental effects of therapeutic interventions could be attributable, at least in part, to modulation of injury and inflammation proximal to the colon.
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Affiliation(s)
- W Elsheikh
- Farncombe Family Digestive Health Research Institute McMaster University, Hamilton, Ontario, Canada
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11
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Abstract
Expression of the long form of the leptin receptor, the isoform that is considered to have full signaling capability, has been reported in the central nervous system and several peripheral cell types. However, only a few cell lines have been shown to express the long form of the receptor. AR42J, a cell line derived from azaserine-treated rat pancreas, is a common model for pancreatic acinar cell secretion. In this study, the presence of leptin-receptor variants and leptin action was evaluated in this cell line. Messenger RNAs for both the long and a short form of the leptin receptor were detected by reverse transcription-polymerase chain reaction (RT-PCR) in AR42J cells, and authenticity of the receptor was confirmed by DNA sequencing. Competitive binding studies demonstrated that binding of radiolabeled leptin was specific and did not cross-react with cholecystokinin (CCK). Biologic effects of leptin on amylase release and intracellular calcium mobilization were further assessed in the presence and the absence of CCK, a known pancreatic secretagogue. Although leptin alone (< or =200 ng/ml) did not affect basal amylase release, it inhibited amylase release stimulated by 1 nM CCK by 48%. Leptin alone had no significant effect on calcium mobilization. However, pretreatment of leptin (10 and 100 ng/ml) enhanced calcium responses stimulated by CCK. These data demonstrate that the rat pancreatic tumor cell line AR42J expresses a functional form of the leptin receptor that modulates the action of CCK in calcium mobilization and amylase release.
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Affiliation(s)
- D M Harris
- Center for Human Nutrition, UCLA School of Medicine, Los Angeles, California, USA.
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