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Colucci R, Pellegrini C, Fornai M, Tirotta E, Antonioli L, Renzulli C, Ghelardi E, Piccoli E, Gentile D, Benvenuti L, Natale G, Fulceri F, Palazón-Riquelme P, López-Castejón G, Blandizzi C, Scarpignato C. Pathophysiology of NSAID-Associated Intestinal Lesions in the Rat: Luminal Bacteria and Mucosal Inflammation as Targets for Prevention. Front Pharmacol 2018; 9:1340. [PMID: 30555323 PMCID: PMC6281992 DOI: 10.3389/fphar.2018.01340] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 10/31/2018] [Indexed: 12/11/2022] Open
Abstract
Non-steroidal anti-inflammatory drugs (NSAIDs) can damage the small intestine, mainly through an involvement of enteric bacteria. This study examined the pathophysiology of NSAID-associated intestinal lesions in a rat model of diclofenac-enteropathy and evaluated the effect of rifaximin on small bowel damage. Enteropathy was induced in 40-week old male rats by intragastric diclofenac (4 mg/kg BID, 14 days). Rifaximin (delayed release formulation) was administered (50 mg/kg BID) 1 h before the NSAID. At the end of treatments, parameters dealing with ileal damage, inflammation, barrier integrity, microbiota composition, and TLR-NF-κB-inflammasome pathway were evaluated. In addition, the modulating effect of rifaximin on NLRP3 inflammasome was tested in an in vitro cell system. Diclofenac induced intestinal damage and inflammation, triggering an increase in tissue concentrations of tumor necrosis factor and interleukin-1β, higher expression of TLR-2 and TLR-4, MyD88, NF-κB and activation of caspase-1. In addition, the NSAID decreased ileal occludin expression and provoked a shift of bacterial phyla toward an increase in Proteobacteria and Bacteroidetes abundance. All these changes were counterbalanced by rifaximin co-administration. This drug was also capable of increasing the proportion of Lactobacilli, a genus depleted by the NSAID. In LPS-primed THP-1 cells stimulated by nigericin (a model to study the NLRP3 inflammasome), rifaximin reduced IL-1β production in a concentration-dependent fashion, this effect being associated with inhibition of the up-stream caspase-1 activation. In conclusion, diclofenac induced ileal mucosal lesions, driving inflammatory pathways and microbiota changes. In conclusion, rifaximin prevents diclofenac-induced enteropathy through both anti-bacterial and anti-inflammatory activities.
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Affiliation(s)
- Rocchina Colucci
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy
| | - Carolina Pellegrini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Matteo Fornai
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Erika Tirotta
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Luca Antonioli
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Cecilia Renzulli
- Reasearch & Development Department, Alfasigma SpA, Bologna, Italy
| | - Emilia Ghelardi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Elena Piccoli
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Daniela Gentile
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Laura Benvenuti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Gianfranco Natale
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Federica Fulceri
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Pablo Palazón-Riquelme
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, United Kingdom
| | - Gloria López-Castejón
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, United Kingdom
| | - Corrado Blandizzi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Carmelo Scarpignato
- Clinical Pharmacology & Digestive Pathophysiology Unit, Department of Clinical & Experimental Medicine, University of Parma, Parma, Italy
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Targeted inhibition of heat shock protein 90 suppresses tumor necrosis factor-α and ameliorates murine intestinal inflammation. Inflamm Bowel Dis 2014; 20:685-94. [PMID: 24552830 PMCID: PMC4418437 DOI: 10.1097/01.mib.0000442839.28664.75] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Inflammatory bowel diseases are chronic intestinal inflammatory diseases thought to reflect a dysregulated immune response. Although antibody-based inhibition of tumor necrosis factor-α (TNF-α) has provided relief to many inflammatory bowel diseases patients, these therapies are either ineffective in a patient subset or lose their efficacy over time, leaving an unmet need for alternatives. Given the critical role of the heat shock response in regulating inflammation, this study proposed to define the impact of selective inhibition of heat shock protein 90 (HSP90) on intestinal inflammation. Using multiple preclinical mouse models of inflammatory bowel diseases, we demonstrate a potent anti-inflammatory effect of selective inhibition of the HSP90 C-terminal ATPase using the compound novobiocin. Novobiocin-attenuated dextran sulfate sodium-induced colitis and CD45RB adoptive-transfer colitis through the suppression of inflammatory cytokine secretion, including TNF-α. In vitro assays demonstrate that CD4 T cells treated with novobiocin produced significantly less TNF-α measured by intracellular cytokine staining and by enzyme-linked immunosorbent assay. This corresponded to significantly decreased nuclear p65 translocation by Western blot and a decrease in nuclear factor-κB luciferase activity in Jurkat T cells. Finally, to verify the anti-TNF action of novobiocin, 20-week-old TNFΔ mice were treated for 2 weeks with subcutaneous administration of novobiocin. This model has high levels of circulating TNF-α and exhibits spontaneous transmural segmental ileitis. Novobiocin treatment significantly reduced inflammatory cell infiltrate in the ileal lamina propria. HSP90 inhibition with novobiocin offers a novel method of inflammatory cytokine suppression without potential for the development of tolerance that limits current antibody-based methods.
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Cottreau J, Baker SF, DuPont HL, Garey KW. Rifaximin: a nonsystemic rifamycin antibiotic for gastrointestinal infections. Expert Rev Anti Infect Ther 2014; 8:747-60. [DOI: 10.1586/eri.10.58] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Kanauchi O, Andoh A, Mitsuyama K. Effects of the modulation of microbiota on the gastrointestinal immune system and bowel function. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:9977-9983. [PMID: 24070265 DOI: 10.1021/jf402441f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The gastrointestinal tract harbors a tremendous number and variety of commensal microbiota. The intestinal mucosa simultaneously absorbs essential nutrients and protects against detrimental antigens or pathogenic microbiota as the first line of defense. Beneficial interactions between the host and microbiota are key requirements for host health. Although the gut microbiota has been previously studied in the context of inflammatory diseases, it has recently become clear that this microbial environment has a beneficial role during normal homeostasis, by modulating the immune system or bowel motor function. Recent studies revealed that microbiota, including their metabolites, modulate key signaling pathways involved in the inflammation of the mucosa or the neurotransmitter system in the gut-brain axis. The underlying molecular mechanisms of host-microbiota interactions are still unclear; however, manipulation of microbiota by probiotics or prebiotics is becoming increasingly recognized as an important therapeutic option, especially for the treatment of the dysfunction or inflammation of the intestinal tract.
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Affiliation(s)
- Osamu Kanauchi
- Group Internal Audit Department, Kirin Holdings Company, Ltd., 4-10-2 Nakano, Nakano-ku, Tokyo 164-0001, Japan
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Komiyama Y, Mitsuyama K, Masuda J, Yamasaki H, Takedatsu H, Andoh A, Tsuruta O, Fukuda M, Kanauchi O. Prebiotic treatment in experimental colitis reduces the risk of colitic cancer. J Gastroenterol Hepatol 2011; 26:1298-308. [PMID: 21303406 DOI: 10.1111/j.1440-1746.2011.06690.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND AND AIM Germinated barley foodstuff (GBF) is a prebiotic product that reduces colonic mucosal inflammation and the clinical symptoms observed in ulcerative colitis (UC). The risk of contracting colorectal cancer is higher in patients with UC than in that of the general population. The aim of this study is to apply this prebiotic approach to control chronic colitis and to reduce the incidence of colitic cancer. METHODS Repeated and intermitted dextran sulfate sodium administration to male Sprague-Dawley rats was used for the chronic and subacute colitis models. GBF was added as the diet (10% w/v). The incidence of adenomatous high-grade dysplasia, and pathophysiological observations, including the proliferative cell nuclear antigen (PCNA) labeling index, and clinical score, cecal organic acid profile, and the accompanying β-glucosidase activity were determined. RESULTS In the chronic phase, the incidence of adenomatous dysplasia was only confirmed in the control group, and the GBF group had no dysplasia in the entire colon; the stratified squamous epithelium area of GBF was significantly lower than that of the controls. GBF treatment significantly lowered the cecal succinate content and significantly increased β-glucosidase activity compared to the controls. In addition, colonic mucosal inflammatory damage was comparable between the two groups, while the PCNA labeling index of the colonic mucosa in the GBF group was significantly lower than that of the control group. However, in the subacute phase, the mucosal damage score of GBF was significantly attenuated, and the PCNA labeling index of the colonic mucosa in the GBF group was significantly higher than that of the control group. CONCLUSION This preliminary study demonstrated that GBF effectively prevents colitis-related dysplasia and inflammatory change in chronic and subacute colitis models by modulating the intestinal environment as a prebiotic. This prebiotic might contribute to the prevention of mucosal damage, to show different proliferative effects on the epithelium in the regeneration and steady states.
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Affiliation(s)
- Yutaka Komiyama
- Central Laboratories for Frontier Technology, Kirin Holdings Co. Ltd., Yokohama, Japan
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Cheng J, Shah YM, Ma X, Pang X, Tanaka T, Kodama T, Krausz KW, Gonzalez FJ. Therapeutic role of rifaximin in inflammatory bowel disease: clinical implication of human pregnane X receptor activation. J Pharmacol Exp Ther 2010; 335:32-41. [PMID: 20627999 DOI: 10.1124/jpet.110.170225] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Human pregnane X receptor (PXR) has been implicated in the pathogenesis of inflammatory bowel disease (IBD). Rifaximin, a human PXR activator, is in clinical trials for treatment of IBD and has demonstrated efficacy in Crohn's disease and active ulcerative colitis. In the current study, the protective and therapeutic role of rifaximin in IBD and its respective mechanism were investigated. PXR-humanized (hPXR), wild-type, and Pxr-null mice were treated with rifaximin in the dextran sulfate sodium (DSS)-induced and trinitrobenzene sulfonic acid (TNBS)-induced IBD models to determine the protective function of human PXR activation in IBD. The therapeutic role of rifaximin was further evaluated in DSS-treated hPXR and Pxr-null mice. Results demonstrated that preadministration of rifaximin ameliorated the clinical hallmarks of colitis in DSS- and TNBS-treated hPXR mice as determined by body weight loss and assessment of diarrhea, rectal bleeding, colon length, and histology. In addition, higher survival rates and recovery from colitis symptoms were observed in hPXR mice, but not in Pxr-null mice, when rifaximin was administered after the onset of symptoms. Nuclear factor κB (NF-κB) target genes were markedly down-regulated in hPXR mice by rifaximin treatment. In vitro NF-κB reporter assays demonstrated inhibition of NF-κB activity after rifaximin treatment in colon-derived cell lines expressing hPXR. These findings demonstrated the preventive and therapeutic role of rifaximin on IBD through human PXR-mediated inhibition of the NF-κB signaling cascade, thus suggesting that human PXR may be an effective target for the treatment of IBD.
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Affiliation(s)
- Jie Cheng
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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A randomized, double-blind, placebo-controlled trial of rifaximin, a nonabsorbable antibiotic, in the treatment of tropical enteropathy. Am J Gastroenterol 2009; 104:2326-33. [PMID: 19491826 PMCID: PMC2758482 DOI: 10.1038/ajg.2009.270] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Tropical enteropathy is characterized by an increased urinary lactulose-to-mannitol (L:M) ratio on a site-specific sugar absorption test and is associated with increased intestinal permeability and decreased nutrient absorptive capacity. The etiology of tropical enteropathy is postulated to be intestinal bacterial overgrowth. This study tested the hypothesis that treatment with a nonabsorbable, broad-spectrum antibiotic, rifaximin, reduces the L:M ratio in rural Malawian children, among whom tropical enteropathy is common. METHODS All children aged 3-5 years from one village were enrolled in a randomized, double-blind, placebo-controlled trial of treatment with rifaximin for 7 days. The L:M ratio was measured before and after treatment, and the change in the L:M ratio was the primary outcome. Secondary outcomes were changes in the urinary sucrose-to-lactulose (SUC:L) and sucralose-to-lactulose (SCL:L) ratios, as well as changes in the fractions of each test sugar recovered in the urine. RESULTS A total of 144 children participated in this study, of whom 76% had an elevated L:M ratio on enrollment (L:M > or = 0.10). Children who received rifaximin did not show an improvement in their L:M ratio compared with those who received placebo (-0.01+/-0.12 vs. 0.02+/-0.16, respectively, P=0.51, mean+/-s.d.), nor were there significant differences between the two groups in excretion of lactulose, mannitol, sucralose, or sucrose, or in the SUC:L and SCL:L ratios. CONCLUSIONS Rifaximin had no effect on the tropical enteropathy of 3-5-year-old Malawian children, suggesting that small-bowel bacterial overgrowth is not an important etiological factor in this condition.
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Straforini G, Brugnera R, Tambasco R, Rizzello F, Gionchetti P, Campieri M. Attualità e controversie nella terapia delle malattie infiammatorie croniche intestinali. ITALIAN JOURNAL OF MEDICINE 2009. [DOI: 10.1016/j.itjm.2009.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Ojetti V, Lauritano EC, Barbaro F, Migneco A, Ainora ME, Fontana L, Gabrielli M, Gasbarrini A. Rifaximin pharmacology and clinical implications. Expert Opin Drug Metab Toxicol 2009; 5:675-82. [PMID: 19442033 DOI: 10.1517/17425250902973695] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Rifaximin is a semisynthetic, rifamycin-based non-systemic antibiotic, with a low gastrointestinal absorption and a good antibacterial activity. The antibacterial action covers Gram-positive and Gram-negative organisms, both aerobes and anaerobes. Its antimicrobial action is based on its property to bind to the beta-subunit of bacterial DNA-dependent RNA polymerase inhibiting, thereby, the bacterial RNA synthesis. Rifaximin contributes to restore gut microflora imbalance, becoming an important therapeutic agent in several organic and functional gastrointestinal diseases such as hepatic encephalopathy, small intestine bacterial overgrowth, inflammatory bowel disease and colonic diverticular disease. This antibiotic has the advantage of low microbial resistance and few systemic adverse events and is safe in all patient populations, including young children.
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Affiliation(s)
- Veronica Ojetti
- Internal Medicine Department, Catholic University of Sacred Heart, Gemelli Hospital, Rome, Italy. veronica.ojetti tin.it
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Huang TY, Chu HC, Lin YL, Lin CK, Hsieh TY, Chang WK, Chao YC, Liao CL. Minocycline attenuates experimental colitis in mice by blocking expression of inducible nitric oxide synthase and matrix metalloproteinases. Toxicol Appl Pharmacol 2009; 237:69-82. [PMID: 19285099 DOI: 10.1016/j.taap.2009.02.026] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Revised: 01/29/2009] [Accepted: 02/24/2009] [Indexed: 12/31/2022]
Abstract
In addition to its antimicrobial activity, minocycline exerts anti-inflammatory effects in several disease models. However, whether minocycline affects the pathogenesis of inflammatory bowel disease has not been determined. We investigated the effects of minocycline on experimental colitis and its underlying mechanisms. Acute and chronic colitis were induced in mice by treatment with dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS), and the effect of minocycline on colonic injury was assessed clinically and histologically. Prophylactic and therapeutic treatment of mice with minocycline significantly diminished mortality rate and attenuated the severity of DSS-induced acute colitis. Mechanistically, minocycline administration suppressed inducible nitric oxide synthase (iNOS) expression and nitrotyrosine production, inhibited proinflammatory cytokine expression, repressed the elevated mRNA expression of matrix metalloproteinases (MMPs) 2, 3, 9, and 13, diminished the apoptotic index in colonic tissues, and inhibited nitric oxide production in the serum of mice with DSS-induced acute colitis. In DSS-induced chronic colitis, minocycline treatment also reduced body weight loss, improved colonic histology, and blocked expression of iNOS, proinflammatory cytokines, and MMPs from colonic tissues. Similarly, minocycline could ameliorate the severity of TNBS-induced acute colitis in mice by decreasing mortality rate and inhibiting proinflammatory cytokine expression in colonic tissues. These results demonstrate that minocycline protects mice against DSS- and TNBS-induced colitis, probably via inhibition of iNOS and MMP expression in intestinal tissues. Therefore, minocycline is a potential remedy for human inflammatory bowel diseases.
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Affiliation(s)
- Tien-Yu Huang
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan
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Muratov V, Ulfgren AK, Engström M, Elvin K, Winqvist O, Löfberg R, Lundahl J. Decreased numbers of FoxP3-positive and TLR-2-positive cells in intestinal mucosa are associated with improvement in patients with active inflammatory bowel disease following selective leukocyte apheresis. J Gastroenterol 2008; 43:277-82. [PMID: 18458843 DOI: 10.1007/s00535-007-2156-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2007] [Accepted: 12/29/2007] [Indexed: 02/04/2023]
Abstract
BACKGROUND Impaired immunological tolerance to commensal enteric flora is considered one possible pathogenic mechanism of inflammatory bowel disease (IBD). Given that regulatory T cells and Toll-like receptor (TLR)-positive cells are key actors in mucosal immune regulation, we aimed to identify the dynamics of these actors in the intestinal mucosa in relation to clinical improvement following selective leukapheresis treatment. METHODS Ten patients with active IBD despite treatment with corticosteroids, immunomodulators, or anti-tumor necrosis factor therapy were assessed by immunohistochemical staining of colorectal mucosal biopsies obtained before and after five sessions (week 7) of granulocyte and monocyte adsorption apheresis (GCAP). The presence of FoxP3-positive regulatory T cells, macrophages, dendritic cells, and TLR-2 and-4 positive cells was determined in relation to short-(week 7) and long-term (week 52) clinical outcome data. RESULTS Following GCAP, the number of FoxP3-(P = 0.012) and TLR-2 (P = 0.008)-positive cells significantly decreased in biopsies after 7 weeks, in parallel with both clinical improvement at week 7 and a longstanding response after 12 months. CONCLUSIONS Downregulation of FoxP3 and TLR-2 cells in the colorectal mucosa mirrors both short-and long-term improvement in patients with active IBD responding to GCAP. This observation suggests a potential role of these cells in the pathogenesis of IBD and the induction of immunological tolerance in the mucosa.
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Affiliation(s)
- Vladislaw Muratov
- Unit of Clinical Immunology, Department of Clinical Immunology and Transfusion Medicine, Karolinska University Hospital and Karolinska Institutet at Karolinska University Hospital, s-171 76, Stockholm, Sweden
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Akpinar HA. Therapy of mild to moderate colonic Crohn’s disease. FALK SYMPOSIUM 2008:221-231. [DOI: 10.1007/978-1-4020-6987-1_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
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Kang SS, Bloom SM, Norian LA, Geske MJ, Flavell RA, Stappenbeck TS, Allen PM. An antibiotic-responsive mouse model of fulminant ulcerative colitis. PLoS Med 2008; 5:e41. [PMID: 18318596 PMCID: PMC2270287 DOI: 10.1371/journal.pmed.0050041] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Accepted: 12/21/2007] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The constellation of human inflammatory bowel disease (IBD) includes ulcerative colitis and Crohn's disease, which both display a wide spectrum in the severity of pathology. One theory is that multiple genetic hits to the host immune system may contribute to the susceptibility and severity of IBD. However, experimental proof of this concept is still lacking. Several genetic mouse models that each recapitulate some aspects of human IBD have utilized a single gene defect to induce colitis. However, none have produced pathology clearly distinguishable as either ulcerative colitis or Crohn's disease, in part because none of them reproduce the most severe forms of disease that are observed in human patients. This lack of severe IBD models has posed a challenge for research into pathogenic mechanisms and development of new treatments. We hypothesized that multiple genetic hits to the regulatory machinery that normally inhibits immune activation in the intestine would generate more severe, reproducible pathology that would mimic either ulcerative colitis or Crohn's disease. METHODS AND FINDINGS We generated a novel mouse line (dnKO) that possessed defects in both TGFbetaRII and IL-10R2 signaling. These mice rapidly and reproducibly developed a disease resembling fulminant human ulcerative colitis that was quite distinct from the much longer and more variable course of pathology observed previously in mice possessing only single defects. Pathogenesis was driven by uncontrolled production of proinflammatory cytokines resulting in large part from T cell activation. The disease process could be significantly ameliorated by administration of antibodies against IFNgamma and TNFalpha and was completely inhibited by a combination of broad-spectrum antibiotics. CONCLUSIONS Here, we develop to our knowledge the first mouse model of fulminant ulcerative colitis by combining multiple genetic hits in immune regulation and demonstrate that the resulting disease is sensitive to both anticytokine therapy and broad-spectrum antibiotics. These findings indicated the IL-10 and TGFbeta pathways synergize to inhibit microbially induced production of proinflammatory cytokines, including IFNgamma and TNFalpha, which are known to play a role in the pathogenesis of human ulcerative colitis. Our findings also provide evidence that broad-spectrum antibiotics may have an application in the treatment of patients with ulcerative colitis. This model system will be useful in the future to explore the microbial factors that induce immune activation and characterize how these interactions produce disease.
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Affiliation(s)
- Silvia S Kang
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
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Mitsuyama K, Sata M. Gut microflora: a new target for therapeutic approaches in inflammatory bowel disease. Expert Opin Ther Targets 2008; 12:301-12. [DOI: 10.1517/14728222.12.3.301] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Swidsinski A, Loening-Baucke V, Bengmark S, Scholze J, Doerffel Y. Bacterial biofilm suppression with antibiotics for ulcerative and indeterminate colitis: consequences of aggressive treatment. Arch Med Res 2007; 39:198-204. [PMID: 18164963 DOI: 10.1016/j.arcmed.2007.08.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 08/13/2007] [Indexed: 12/13/2022]
Abstract
BACKGROUND Antibiotics are commonly used in inflammatory bowel disease (IBD). Little is known about their effect on the mucosal flora. METHODS The mucosal flora was investigated in colonoscopic biopsies from six groups of 20 IBD patients each. Patients were selected with regard to duration of/interval to combined metronidazole and ciprofloxacin therapy: group I patients with 1 day and group II with 7-14 days of antibiotic therapy, group III-V patients evaluated 1-4 weeks, 2-18 weeks, 26-36 weeks after cessation of antibiotic therapy, respectively. The control group VI included patients without antibiotic therapy. Thirty different fluorescent in situ hybridization (FISH) probes representative of the diversity of the human intestinal flora were applied to all specimens. RESULTS Bacteria adherent to mucosa could be seen exclusively in DAPI stain and were practically nonamenable to FISH probes in patients on antibiotics (0.001-3+/-0.001-5)x10(10)/mL. Occurrence and concentrations were significantly reduced in groups I and II as compared to untreated controls. The mucosal bacteria were significantly augmented after cessation of antibiotic therapy in group III (13.2+/-4.3) and group IV (5.8+/-2) but not in group V (1.1+/-0.8) as compared to group VI (0.5+/-0.4)x10(10)/mL. Neither Bacteroides nor Enterobacteriaceae groups were permanently suppressed by metronidazole-ciprofloxacin therapy. CONCLUSIONS The suppressing effects of antibiotics on the mucosal flora are accompanied by massive rebound effects. The concentrations of mucosal bacteria are dramatically increased as soon as 1 week after cessation of antibiotic therapy, remaining at a level that is at least one power higher over a period of 5 months as compared to the group without antibiotic treatment.
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Affiliation(s)
- Alexander Swidsinski
- Humboldt University, Charité Hospital, CCM, Laboratory for Molecular Genetics, Polymicrobial Infections and Biofilms, Berlin, Germany.
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Bremner AR, Beattie RM. Recent advances in the medical therapy of Crohn's disease in childhood. Expert Opin Pharmacother 2007; 8:2553-68. [DOI: 10.1517/14656566.8.15.2553] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Abstract
Ulcerative colitis (UC) and Crohn's disease (CD), collectively referred to as inflammatory bowel disease (IBD), present with differing histologic and cytokine profiles. While the precise mechanisms underlying the development of IBD are not known, sufficient data have been collected to suggest that it results from a complex interplay of genetic, environmental, and immunologic factors. Animal models of colitis, along with a more detailed understanding of the immune response in the normal bowel, have led to unifying hypotheses regarding the pathogenesis. An inappropriate mucosal immune response to normal intestinal constituents is a key feature, leading to an imbalance in local pro- and anti-inflammatory cytokines. Neutrophil and monocyte influx occurs with subsequent secretion of oxygen radicals and enzymes, leading to tissue damage. Therapy of IBD has improved and expanded as the understanding of disease mechanisms has evolved. Pharmacologic agents such as aminosalicylates, azathioprine/6-mercaptopurine, or steroids are the mainstays of therapy. Newer agents including monoclonal antibodies targeted to specific proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha), have emerged and provide great clinical benefit, but unknown long-term toxicity and immunogenicity may limit their use.
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Affiliation(s)
- Steven J Brown
- Division of Gastroenterology, Department of Medicine, The Mount Sinai School of Medicine, New York, New York 10029, USA
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Cui DL, Chen W, Yao XX. Clinical application progress of Rifaximin in the treatment of digestive diseases. Shijie Huaren Xiaohua Zazhi 2007; 15:1457-1462. [DOI: 10.11569/wcjd.v15.i13.1457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Rifaximin, a derivative of rifamycin, has high antibacterial activity on various kinds of Gram-positive and -negative aerobes and anaerobes, and it is a new drug in the treatment of giardiasis. Rifaximin is not easy to be absorbed after oral administration, and mild systemic adverse reaction is the main characteristic. Recently, Rifaximin has been widely and effectively used in the therapy of many diseases related to intestinal bacterial infection such as hepatic encephalopathy, diverticular disease, overgrowth of intestinal bacteria, inflammatory bowel disease (IBD) and H. pylori infection. The above advances were reviewed in the present article.
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Ma X, Shah YM, Guo GL, Wang T, Krausz KW, Idle JR, Gonzalez FJ. Rifaximin is a gut-specific human pregnane X receptor activator. J Pharmacol Exp Ther 2007; 322:391-8. [PMID: 17442842 DOI: 10.1124/jpet.107.121913] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Rifaximin, a rifamycin analog approved for the treatment of travelers' diarrhea, is also beneficial in the treatment of multiple chronic gastrointestinal disorders. However, the mechanisms contributing to the effects of rifaximin on chronic gastrointestinal disorders are not fully understood. In the current study, rifaximin was investigated for its role in activation of the pregnane X receptor (PXR), a nuclear receptor that regulates genes involved in xenobiotic and limited endobiotic deposition and detoxication. PXR-humanized (hPXR), Pxr-null, and wild-type mice were treated orally with rifaximin, and rifampicin, a well characterized human PXR ligand. Rifaximin was highly concentrated in the intestinal tract compared with rifampicin. Rifaximin treatment resulted in significant induction of PXR target genes in the intestine of hPXR mice, but not in wild-type and Pxr-null mice. However, rifaximin treatment demonstrated no significant effect on hepatic PXR target genes in wild-type, Pxr-null, and hPXR mice. Consistent with the in vivo data, cell-based reporter gene assay revealed rifaximin-mediated activation of human PXR, but not the other xenobiotic nuclear receptors constitutive androstane receptor, peroxisome proliferator-activated receptor (PPAR)alpha, PPARgamma, and farnesoid X receptor. Pretreatment with rifaximin did not affect the pharmacokinetics of the CYP3A substrate midazolam, but it increased the C(max) and decreased T(max) of 1'-hydroxymidazolam. Collectively, the current study identified rifaximin as a gut-specific human PXR ligand, and it provided further evidence for the utility of hPXR mice as a critical tool for the study of human PXR activators. Further human studies are suggested to assess the potential role of rifaximin-mediated gut PXR activation in therapeutics of chronic gastrointestinal disorders.
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Affiliation(s)
- Xiaochao Ma
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bldg. 37, Room 3106, Bethesda, MD 20892, USA
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