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Garcia Moreno AS, Guicciardi ME, Wixom AQ, Jessen E, Yang J, Ilyas SI, Bianchi JK, Pinto e Vairo F, Lazaridis KN, Gores GJ. IL-17 signaling in primary sclerosing cholangitis patient-derived organoids. Hepatol Commun 2024; 8:e0454. [PMID: 38829197 PMCID: PMC11150034 DOI: 10.1097/hc9.0000000000000454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 03/15/2024] [Indexed: 06/05/2024] Open
Abstract
BACKGROUND The pathogenesis of primary sclerosing cholangitis (PSC) is unclear, although studies implicate IL-17A as an inflammatory mediator in this disease. However, a direct assessment of IL-17 signaling in PSC cholangiocytes is lacking. In this study, we aimed to investigate and characterize the response of PSC extrahepatic cholangiocyte organoids (ECO) to IL-17A stimulation. METHODS Cholangiocytes obtained from patients with PSC and without PSC by endoscopic retrograde cholangiography were cultured as ECO. The ECO were treated with vehicle or IL-17A and assessed by transcriptomics, secretome analysis, and genome sequencing. RESULTS Unsupervised clustering of all integrated single-cell RNA sequencing data identified 8 cholangiocyte clusters that did not differ between PSC and non-PSC ECO. However, PSC ECO cells demonstrated a robust response to IL-17 treatment, as noted by an increased number of differentially expressed genes by transcriptomics and more abundant chemokine and cytokine expression and secretion. After rigorous filtering, genome sequencing identified candidate somatic variants shared among PSC ECO from unrelated individuals. However, no candidate rare variants in genes regulating the IL-17 pathway were identified, but rare variants regulating the MAPK signaling pathway were present in all PSC ECO. CONCLUSIONS PSC and non-PSC patient-derived ECO respond differently to IL-17 stimulation, implicating this pathway in the pathogenesis of PSC.
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Affiliation(s)
- Ana S. Garcia Moreno
- Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Maria E. Guicciardi
- Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Alexander Q. Wixom
- Department of Quantitative Health Sciences, Mayo Clinic, Rochester, Minnesota, USA
| | - Erik Jessen
- Department of Quantitative Health Sciences, Mayo Clinic, Rochester, Minnesota, USA
| | - Jingchun Yang
- Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Sumera I. Ilyas
- Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Jackie K. Bianchi
- Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Filippo Pinto e Vairo
- Center for Individualized Medicine, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
- Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Konstantinos N. Lazaridis
- Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Gregory J. Gores
- Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
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2
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Alula KM, Theiss AL. Autophagy in Crohn's Disease: Converging on Dysfunctional Innate Immunity. Cells 2023; 12:1779. [PMID: 37443813 PMCID: PMC10341259 DOI: 10.3390/cells12131779] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 06/29/2023] [Accepted: 06/30/2023] [Indexed: 07/15/2023] Open
Abstract
Crohn's disease (CD) is a chronic inflammatory bowel disease marked by relapsing, transmural intestinal inflammation driven by innate and adaptive immune responses. Autophagy is a multi-step process that plays a critical role in maintaining cellular homeostasis by degrading intracellular components, such as damaged organelles and invading bacteria. Dysregulation of autophagy in CD is revealed by the identification of several susceptibility genes, including ATG16L1, IRGM, NOD2, LRRK2, ULK1, ATG4, and TCF4, that are involved in autophagy. In this review, the role of altered autophagy in the mucosal innate immune response in the context of CD is discussed, with a specific focus on dendritic cells, macrophages, Paneth cells, and goblet cells. Selective autophagy, such as xenophagy, ERphagy, and mitophagy, that play crucial roles in maintaining intestinal homeostasis in these innate immune cells, are discussed. As our understanding of autophagy in CD pathogenesis evolves, the development of autophagy-targeted therapeutics may benefit subsets of patients harboring impaired autophagy.
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Affiliation(s)
| | - Arianne L. Theiss
- Division of Gastroenterology & Hepatology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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3
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Telocytes’ Role in Modulating Gut Motility Function and Development: Medical Hypotheses and Literature Review. Int J Mol Sci 2022; 23:ijms23137017. [PMID: 35806023 PMCID: PMC9267102 DOI: 10.3390/ijms23137017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 06/19/2022] [Accepted: 06/22/2022] [Indexed: 11/17/2022] Open
Abstract
This review article explores the telocytes’ roles in inflammatory bowel diseases (IBD), presenting the mechanisms and hypotheses related to epithelial regeneration, progressive fibrosis, and dysmotility as a consequence of TCs’ reduced or absent number. Based on the presented mechanisms and hypotheses, we aim to provide a functional model to illustrate TCs’ possible roles in the normal and pathological functioning of the digestive tract. TCs are influenced by the compression of nearby blood vessels and the degree of fibrosis of the surrounding tissues and mediate these processes in response. The changes in intestinal tube vascularization induced by the movement of the food bowl, and the consequent pH changes that show an anisotropy in the thickness of the intestinal tube wall, have led to the identification of a pattern of intestinal tube development based on telocytes’ ability to communicate and modulate surrounding cell functions. In the construction of the theoretical model, given the predictable occurrence of colic in the infant, the two-layer arrangement of the nerve plexuses associated with the intestinal tube was considered to be incompletely adapted to the motility required with a diversified diet. There is resulting evidence of possible therapeutic targets for diseases associated with changes in local nerve tissue development.
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4
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LncRNA: A Potential Research Direction in Intestinal Barrier Function. Dig Dis Sci 2021; 66:1400-1408. [PMID: 32591966 DOI: 10.1007/s10620-020-06417-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 06/14/2020] [Indexed: 02/07/2023]
Abstract
Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides and play important roles in a variety of diseases. LncRNAs are involved in many biologic processes including cell differentiation, development, and apoptosis. The intestinal barrier is considered one of the most important protective barriers in humans. Severe damage or dysfunction of the intestinal barrier may be associated with the occurrence and development of many diseases, such as inflammatory bowel disease and ulcerative colitis. LncRNAs have been found to be associated with intestinal barrier function in some studies, which are at an early stage. In this review, we introduce the roles of LncRNAs in the intestinal barrier and investigate the possibility of lncRNAs as a research field in the intestinal barrier.
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5
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Ehrlich AM, Pacheco AR, Henrick BM, Taft D, Xu G, Huda MN, Mishchuk D, Goodson ML, Slupsky C, Barile D, Lebrilla CB, Stephensen CB, Mills DA, Raybould HE. Indole-3-lactic acid associated with Bifidobacterium-dominated microbiota significantly decreases inflammation in intestinal epithelial cells. BMC Microbiol 2020; 20:357. [PMID: 33225894 PMCID: PMC7681996 DOI: 10.1186/s12866-020-02023-y] [Citation(s) in RCA: 138] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 10/27/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Bifidobacterium longum subsp. infantis (B. infantis) is a commensal bacterium that colonizes the gastrointestinal tract of breast-fed infants. B. infantis can efficiently utilize the abundant supply of oligosaccharides found in human milk (HMO) to help establish residence. We hypothesized that metabolites from B. infantis grown on HMO produce a beneficial effect on the host. RESULTS In a previous study, we demonstrated that B. infantis routinely dominated the fecal microbiota of a breast fed Bangladeshi infant cohort (1). Characterization of the fecal metabolome of binned samples representing high and low B. infantis populations from this cohort revealed higher amounts of the tryptophan metabolite indole-3-lactic acid (ILA) in feces with high levels of B. infantis. Further in vitro analysis confirmed that B. infantis produced significantly greater quantities of the ILA when grown on HMO versus lactose, suggesting a growth substrate relationship to ILA production. The direct effects of ILA were assessed in a macrophage cell line and intestinal epithelial cell lines. ILA (1-10 mM) significantly attenuated lipopolysaccharide (LPS)-induced activation of NF-kB in macrophages. ILA significantly attenuated TNF-α- and LPS-induced increase in the pro-inflammatory cytokine IL-8 in intestinal epithelial cells. ILA increased mRNA expression of the aryl hydrogen receptor (AhR)-target gene CYP1A1 and nuclear factor erythroid 2-related factor 2 (Nrf2)-targeted genes glutathione reductase 2 (GPX2), superoxide dismutase 2 (SOD2), and NAD(P) H dehydrogenase (NQO1). Pretreatment with either the AhR antagonist or Nrf-2 antagonist inhibited the response of ILA on downstream effectors. CONCLUSIONS These findings suggest that ILA, a predominant metabolite from B. infantis grown on HMO and elevated in infant stool high in B. infantis, and protects gut epithelial cells in culture via activation of the AhR and Nrf2 pathway.
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Affiliation(s)
- Amy M Ehrlich
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
| | - Alline R Pacheco
- Foods for Health Institute, University of California, Davis, CA, USA
- Department of Food Science and Technology, University of CA, Davis, CA, USA
| | - Bethany M Henrick
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
- Foods for Health Institute, University of California, Davis, CA, USA
- Department of Food Science and Technology, University of CA, Davis, CA, USA
| | - Diana Taft
- Foods for Health Institute, University of California, Davis, CA, USA
- Department of Food Science and Technology, University of CA, Davis, CA, USA
| | - Gege Xu
- Department of Chemistry, University of California, Davis, CA, USA
| | - M Nazmul Huda
- Enteric and Respiratory Infections Unit, Infectious Diseases Division, icddr,b, Dhaka, Bangladesh
- US Department of Agriculture, Western Human Nutrition Research Center, Davis, CA, USA
| | - Darya Mishchuk
- Department of Food Science and Technology, University of CA, Davis, CA, USA
| | - Michael L Goodson
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
| | - Carolyn Slupsky
- Department of Food Science and Technology, University of CA, Davis, CA, USA
- Department of Nutrition, University of California, Davis, CA, USA
| | - Daniela Barile
- Foods for Health Institute, University of California, Davis, CA, USA
- Department of Food Science and Technology, University of CA, Davis, CA, USA
| | | | - Charles B Stephensen
- US Department of Agriculture, Western Human Nutrition Research Center, Davis, CA, USA
- Department of Nutrition, University of California, Davis, CA, USA
| | - David A Mills
- Foods for Health Institute, University of California, Davis, CA, USA
- Department of Food Science and Technology, University of CA, Davis, CA, USA
| | - Helen E Raybould
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA.
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Diminished DEFA6 Expression in Paneth Cells Is Associated with Necrotizing Enterocolitis. Gastroenterol Res Pract 2018; 2018:7345426. [PMID: 30420878 PMCID: PMC6215571 DOI: 10.1155/2018/7345426] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 08/28/2018] [Indexed: 01/05/2023] Open
Abstract
Background Necrotizing enterocolitis (NEC) is the most common gastrointestinal disorder in premature infants with a high morbidity and mortality. Paneth cell dysfunction has been suggested to be involved in the pathogenesis of NEC. Defensin alpha-6 (DEFA6) is a specific marker for Paneth cells acting as part of the innate immunity in the human intestines. The aim of this study was to investigate the expression of DEFA6 in infants with NEC. Materials and Methods Infants who underwent bowel resection for NEC at level III NICU in Sweden between August 2004 and September 2013 were eligible for the study. Macroscopically vital tissues were selected for histopathological evaluation. All infants in the control group underwent laparotomy and had ileostomy due to dysmotility, and samples were taken from the site of the stoma. DEFA6 expression was studied by immunohistochemistry. Digital image analysis was used for an objective and precise description of the samples. Results A total of 12 infants were included in the study, eight with NEC and four controls. The tissue samples were taken from the colon (n = 1), jejunum (n = 1), and ileum (n = 10). Both the NEC and control groups consisted of extremely premature and term infants (control group: 25-40 gestational weeks, NEC group: 23-39 gestational weeks). The postnatal age at the time of surgery varied in both groups (control group: 4-47 days, NEC group: 4-50 days). DEFA6 expression in the NEC group was significantly lower than that in the control group and did not correlate with gestational age. Conclusion The diminished DEFA6 expression in Paneth cells associated with NEC in this study supports the hypothesis that alpha-defensins are involved in the pathophysiology of NEC. Future studies are needed to elucidate the role of alpha-defensins in NEC aiming at finding preventive and therapeutic strategies against NEC.
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The PSMP-CCR2 interactions trigger monocyte/macrophage-dependent colitis. Sci Rep 2017; 7:5107. [PMID: 28698550 PMCID: PMC5506041 DOI: 10.1038/s41598-017-05255-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 05/25/2017] [Indexed: 12/25/2022] Open
Abstract
Monocytes/macrophages have been found to be an important component of colitis. However, the key chemokine that initiates the CCR2+ monocytes migration from circulation to colitis tissue remains to be undiscovered. PC3-secreted microprotein (PSMP) is a novel chemokine whose receptor is CCR2. The physiological and pathological functions of PSMP have not yet been reported. In this study, PSMP was found to be expressed in colitis and colonic tumor tissues from patients and significantly up-regulated in mouse DSS-induced colitis tissues. PSMP overexpression in the colon aggravated the DSS-induced colitis and the anti-PSMP neutralizing antibody mollified the colitis by reducing macrophage infiltration and inhibiting the expression of IL-6, TNF-α and CCL2. Furthermore, we demonstrated that lipopolysaccharide and muramyl dipeptide induced PSMP expression in the colonic epithelial cells. PSMP was up-regulated in the initial stage prior to IL-6, TNF-α and CCL2 up-regulated expression in DSS colitis and promoted the M1 macrophages to produce CCL2. PSMP chemo-attracted Ly6Chi monocytes in a CCR2 dependent manner via in situ chemotaxis and adoptive transfer assays. Our data identify PSMP as a key molecule in ulcerative colitis, which provides a novel mechanism of monocyte/macrophage migration that affects gut innate immunity and makes PSMP a potential target for controlling colitis.
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8
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Alexander DB, Iigo M, Abdelgied M, Ozeki K, Tanida S, Joh T, Takahashi S, Tsuda H. Bovine lactoferrin and Crohn's disease: a case study. Biochem Cell Biol 2016; 95:133-141. [PMID: 28165294 DOI: 10.1139/bcb-2016-0107] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A 22-year-old male suffering from abdominal pain, repeated diarrhea, and weight loss visited the Digestive Disease Department of Nagoya City University Hospital on 19 December 2011. He was hospitalized and diagnosed with Crohn's colitis. His Crohn's Disease Activity Index (CDAI) was 415. Treatment by granulocyte apheresis, mesalazine, and adalimumab was started. His CDAI was 314 on 30 December and 215 on 5 January. A colonoscopic examination on 19 January showed almost complete remission in the transverse colon and marked remission in the rectum. Mesalazine therapy was stopped on 28 February, and the patient was instructed to self-inject 40 mg of adalimumab every other week. His CDAI was 50 on 10 April, indicating clinical remission. His last self-injection of adalimumab was on 24 April 2012, and he started taking 1 g of bovine lactoferrin (bLF) daily. His CDAI was 35 on 8 January 2013. He continued taking 1 g of bLF daily without any other treatment for Crohn's disease. Laboratory blood tests on 7 September 2015 showed no sign of disease recurrence, and a colonoscopic examination on 23 October 2015 showed almost complete mucosal healing. This case indicates that ingestion of bLF to maintain Crohn's disease in a remissive state should be further explored.
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Affiliation(s)
| | - Masaaki Iigo
- a Nanotoxicology Project, Nagoya City University, Nagoya, Japan
| | - Mohamed Abdelgied
- a Nanotoxicology Project, Nagoya City University, Nagoya, Japan.,b Department of Experimental Pathology and Tumor Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.,c Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Keiji Ozeki
- d Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Satoshi Tanida
- d Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Takashi Joh
- d Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Satoru Takahashi
- b Department of Experimental Pathology and Tumor Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Hiroyuki Tsuda
- a Nanotoxicology Project, Nagoya City University, Nagoya, Japan
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9
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Measured Effects of Wnt3a on Proliferation of HEK293T Cells Depend on the Applied Assay. Int J Cell Biol 2015; 2015:928502. [PMID: 26798342 PMCID: PMC4700183 DOI: 10.1155/2015/928502] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 11/24/2015] [Accepted: 12/06/2015] [Indexed: 01/11/2023] Open
Abstract
The Wnt signaling pathway has been associated with many essential cell processes. This study aims to examine the effects of Wnt signaling on proliferation of cultured HEK293T cells. Cells were incubated with Wnt3a, and the activation of the Wnt pathway was followed by analysis of the level of the β-catenin protein and of the expression levels of the target genes MYC and CCND1. The level of β-catenin protein increased up to fourfold. While the mRNA levels of c-Myc and cyclin D1 increased slightly, the protein levels increased up to a factor of 1.5. Remarkably, MTT and BrdU assays showed different results when measuring the proliferation rate of Wnt3a stimulated HEK293T cells. In the BrdU assays an increase of the proliferation rate could be detected, which correlated to the applied Wnt3a concentration. Oppositely, this correlation could not be shown in the MTT assays. The MTT results, which are based on the mitochondrial activity, were confirmed by analysis of the succinate dehydrogenase complex by immunofluorescence and by western blotting. Taken together, our study shows that Wnt3a activates proliferation of HEK293 cells. These effects can be detected by measuring DNA synthesis rather than by measuring changes of mitochondrial activity.
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10
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Intestinal Permeability in Inflammatory Bowel Disease: Pathogenesis, Clinical Evaluation, and Therapy of Leaky Gut. Mediators Inflamm 2015; 2015:628157. [PMID: 26582965 PMCID: PMC4637104 DOI: 10.1155/2015/628157] [Citation(s) in RCA: 463] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 09/21/2015] [Indexed: 12/13/2022] Open
Abstract
The pathogenesis of inflammatory bowel disease (IBD) is multifactorial with data suggesting the role of a disturbed interaction between the gut and the intestinal microbiota. A defective mucosal barrier may result in increased intestinal permeability which promotes the exposition to luminal content and triggers an immunological response that promotes intestinal inflammation. IBD patients display several defects in the many specialized components of mucosal barrier, from the mucus layer composition to the adhesion molecules that regulate paracellular permeability. These alterations may represent a primary dysfunction in Crohn's disease, but they may also perpetuate chronic mucosal inflammation in ulcerative colitis. In clinical practice, several studies have documented that changes in intestinal permeability can predict IBD course. Functional tests, such as the sugar absorption tests or the novel imaging technique using confocal laser endomicroscopy, allow an in vivo assessment of gut barrier integrity. Antitumor necrosis factor-α (TNF-α) therapy reduces mucosal inflammation and restores intestinal permeability in IBD patients. Butyrate, zinc, and some probiotics also ameliorate mucosal barrier dysfunction but their use is still limited and further studies are needed before considering permeability manipulation as a therapeutic target in IBD.
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11
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Lahad A, Weiss B. Current therapy of pediatric Crohn’s disease. World J Gastrointest Pathophysiol 2015; 6:33-42. [PMID: 25977836 PMCID: PMC4419092 DOI: 10.4291/wjgp.v6.i2.33] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 04/02/2015] [Indexed: 02/06/2023] Open
Abstract
Inflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis, are chronic relapsing and remitting diseases of the bowel, with an unknown etiology and appear to involve interaction between genetic susceptibility, environmental factors and the immune system. Although our knowledge and understanding of the pathogenesis and causes of IBD have improved significantly, the incidence in the pediatric population is still rising. In the last decade more drugs and treatment option have become available including 5-aminosalicylate, antibiotics, corticosteroids, immunomodulators and biological agents. Before the use of anti-tumor necrosis factor (TNF)-α became available to patients with IBD, the risk for surgery within five years of diagnosis was very high, however, with anti-TNF-α treatment the risk of surgery has decreased significantly. In the pediatric population a remission in disease can be achieved by exclusive enteral nutrition. Exclusive enteral nutrition also has an important role in the improvement of nutritional status and maintained growth. In this review we summarize the current therapeutic treatments in CD. The progress in the treatment options and the development of new drugs has led to optimized tactics for achieving the primary clinical goals of therapy - induction and maintenance of remission while improving the patient’s growth and overall well-being.
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12
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Wan LYM, Chen ZJ, Shah NP, El-Nezami H. Modulation of Intestinal Epithelial Defense Responses by Probiotic Bacteria. Crit Rev Food Sci Nutr 2015; 56:2628-41. [DOI: 10.1080/10408398.2014.905450] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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13
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Antoni L, Nuding S, Wehkamp J, Stange EF. Intestinal barrier in inflammatory bowel disease. World J Gastroenterol 2014; 20:1165-1179. [PMID: 24574793 PMCID: PMC3921501 DOI: 10.3748/wjg.v20.i5.1165] [Citation(s) in RCA: 284] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 11/08/2013] [Accepted: 12/13/2013] [Indexed: 02/06/2023] Open
Abstract
A complex mucosal barrier protects as the first line of defense the surface of the healthy intestinal tract from adhesion and invasion by luminal microorganisms. In this review, we provide an overview about the major components of this protective system as for example an intact epithelium, the synthesis of various antimicrobial peptides (AMPs) and the formation of the mucus layer. We highlight the crucial importance of their correct functioning for the maintenance of a proper intestinal function and the prevention of dysbiosis and disease. Barrier disturbances including a defective production of AMPs, alterations in thickness or composition of the intestinal mucus layer, alterations of pattern-recognition receptors, defects in the process of autophagy as well as unresolved endoplasmic reticulum stress result in an inadequate host protection and are thought to play a crucial role in the pathogenesis of the inflammatory bowel diseases Crohn’s disease and ulcerative colitis.
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14
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Abstract
The pathogenesis of inflammatory bowel disease (IBD) is very complex, including a variety of genetic and environmental contributing factors. In this context, over the past few years, a picture of IBD as a primary defect of the innate immune system rather than the adaptive immune system has evolved. The intestinal antimicrobial barrier morphologically consists of a single layer of epithelial cells and the mucus and constitutes the first defense mechanism against the microbial burden of the gut. From a more mechanistic point of view, this barrier additionally depends on a crucial interplay between the mucus and antimicrobial peptides like for instance defensins. Disturbances in this system are in the pathophysiological center stage of IBD genesis and progression. In this article we will give a short overview about some of the key mechanisms in this context with special attention on defensins and the mucus layer.
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Affiliation(s)
- Thomas Klag
- Department of Internal Medicine I, Robert Bosch Hospital, Stuttgart, Germany
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15
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Lin YT, Verma A, Hodgkinson CP. Toll-like receptors and human disease: lessons from single nucleotide polymorphisms. Curr Genomics 2013; 13:633-45. [PMID: 23730203 PMCID: PMC3492803 DOI: 10.2174/138920212803759712] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2012] [Revised: 10/08/2012] [Accepted: 10/08/2012] [Indexed: 12/13/2022] Open
Abstract
Toll-like receptors (TLRs), a large group of proteins which recognize various pathogen-associated molecular patterns, are critical for the normal function of the innate immune system. Following their discovery many single nucleotide polymorphisms within TLRs and components of their signaling machinery have been discovered and subsequently implicated in a wide range of human diseases including atherosclerosis, sepsis, asthma, and immunodeficiency. This review discusses the effect of genetic variation on TLR function and how they may precipitate disease.
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Affiliation(s)
- Yi-Tzu Lin
- Department of Medicine, Duke University Medical Center & Mandel Center for Hypertension and Atherosclerosis Research, Durham, NC 27710, USA
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16
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Mohan M, Kaushal D, Aye PP, Alvarez X, Veazey RS, Lackner AA. Focused examination of the intestinal epithelium reveals transcriptional signatures consistent with disturbances in enterocyte maturation and differentiation during the course of SIV infection. PLoS One 2013; 8:e60122. [PMID: 23593167 PMCID: PMC3621888 DOI: 10.1371/journal.pone.0060122] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 02/21/2013] [Indexed: 12/29/2022] Open
Abstract
The Gastrointestinal (GI) tract plays a pivotal role in AIDS pathogenesis as it is the primary site for viral transmission, replication and CD4+ T cell destruction. Accordingly, GI disease (enteropathy) has become a well-known complication and a driver of AIDS progression. To better understand the molecular mechanisms underlying GI disease we analyzed global gene expression profiles sequentially in the intestinal epithelium of the same animals before SIV infection and at 21 and 90 days post infection (DPI). More importantly we obtained sequential excisional intestinal biopsies and examined distinct mucosal components (epithelium. intraepithelial lymphocytes, lamina propria lymphocytes, fibrovascular stroma) separately. Here we report data pertaining to the epithelium. Overall genes associated with epithelial cell renewal/proliferation/differentiation, permeability and adhesion were significantly down regulated (<1.5–7 fold) at 21 and 90DPI. Genes regulating focal adhesions (n = 6), gap junctions (n = 3), ErbB (n = 3) and Wnt signaling (n = 4) were markedly down at 21DPI and the number of genes in each of these groups that were down regulated doubled between 21 and 90DPI. Notable genes included FAK, ITGA6, PDGF, TGFβ3, Ezrin, FZD6, WNT10A, and TCF7L2. In addition, at 90DPI genes regulating ECM-receptor interactions (laminins and ITGB1), epithelial cell gene expression (PDX1, KLF6), polarity/tight junction formation (PARD3B&6B) and histone demethylase (JMJD3) were also down regulated. In contrast, expression of NOTCH3, notch target genes (HES4, HES7) and EZH2 (histone methyltransferase) were significantly increased at 90DPI. The altered expression of genes linked to Wnt signaling together with decreased expression of PDX1, PARD3B, PARD6B and SDK1 suggests marked perturbations in intestinal epithelial function and homeostasis leading to breakdown of the mucosal barrier. More importantly, the divergent expression patterns of EZH2 and JMJD3 suggests that an epigenetic mechanism involving histone modifications may contribute to the massive decrease in gene expression at 90DPI leading to defects in enterocyte maturation and differentiation.
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Affiliation(s)
- Mahesh Mohan
- Division of Comparative Pathology, Tulane National Primate Research Center, Covington, Louisiana, United States of America
| | - Deepak Kaushal
- Division of Bacteriology and Parasitology, Tulane National Primate Research Center, Covington, Louisiana, United States of America
| | - Pyone P. Aye
- Division of Comparative Pathology, Tulane National Primate Research Center, Covington, Louisiana, United States of America
| | - Xavier Alvarez
- Division of Comparative Pathology, Tulane National Primate Research Center, Covington, Louisiana, United States of America
| | - Ronald S. Veazey
- Division of Comparative Pathology, Tulane National Primate Research Center, Covington, Louisiana, United States of America
| | - Andrew A. Lackner
- Division of Comparative Pathology, Tulane National Primate Research Center, Covington, Louisiana, United States of America
- * E-mail:
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Becker S, Oelschlaeger TA, Wullaert A, Pasparakis M, Wehkamp J, Stange EF, Gersemann M. Bacteria regulate intestinal epithelial cell differentiation factors both in vitro and in vivo. PLoS One 2013; 8:e55620. [PMID: 23418447 PMCID: PMC3572096 DOI: 10.1371/journal.pone.0055620] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 01/03/2013] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND The human colon harbours a plethora of bacteria known to broadly impact on mucosal metabolism and function and thought to be involved in inflammatory bowel disease pathogenesis and colon cancer development. In this report, we investigated the effect of colonic bacteria on epithelial cell differentiation factors in vitro and in vivo. As key transcription factors we focused on Hes1, known to direct towards an absorptive cell fate, Hath1 and KLF4, which govern goblet cell. METHODS Expression of the transcription factors Hes1, Hath1 and KLF4, the mucins Muc1 and Muc2 and the defensin HBD2 were measured by real-time PCR in LS174T cells following incubation with several heat-inactivated E. coli strains, including the probiotic E. coli Nissle 1917+/- flagellin, Lactobacilli and Bifidobacteria. For protein detection Western blot experiments and chamber-slide immunostaining were performed. Finally, mRNA and protein expression of these factors was evaluated in the colon of germfree vs. specific pathogen free vs. conventionalized mice and colonic goblet cells were counted. RESULTS Expression of Hes1 and Hath1, and to a minor degree also of KLF4, was reduced by E. coli K-12 and E. coli Nissle 1917. In contrast, Muc1 and HBD2 expression were significantly enhanced, independent of the Notch signalling pathway. Probiotic E. coli Nissle 1917 regulated Hes1, Hath1, Muc1 and HBD2 through flagellin. In vivo experiments confirmed the observed in vitro effects of bacteria by a diminished colonic expression of Hath1 and KLF4 in specific pathogen free and conventionalized mice as compared to germ free mice whereas the number of goblet cells was unchanged in these mice. CONCLUSIONS Intestinal bacteria influence the intestinal epithelial differentiation factors Hes1, Hath1 and KLF4, as well as Muc1 and HBD2, in vitro and in vivo. The induction of Muc1 and HBD2 seems to be triggered directly by bacteria and not by Notch.
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Affiliation(s)
- Svetlana Becker
- Dr. Margarete Fischer-Bosch Institute for Clinical Pharmacology, Stuttgart, Germany
- University of Tübingen, Tübingen, Germany
| | | | - Andy Wullaert
- Institute for Genetics, University of Cologne, Cologne, Germany
| | - Manolis Pasparakis
- Institute for Genetics, University of Cologne, Cologne, Germany
- EMBL Mouse Biology Unit, Monterotondo, Italy
| | - Jan Wehkamp
- Dr. Margarete Fischer-Bosch Institute for Clinical Pharmacology, Stuttgart, Germany
- University of Tübingen, Tübingen, Germany
- Department of Internal Medicine I, Robert Bosch Hospital, Stuttgart, Germany
| | - Eduard F. Stange
- Department of Internal Medicine I, Robert Bosch Hospital, Stuttgart, Germany
| | - Michael Gersemann
- Dr. Margarete Fischer-Bosch Institute for Clinical Pharmacology, Stuttgart, Germany
- University of Tübingen, Tübingen, Germany
- Department of Internal Medicine I, Robert Bosch Hospital, Stuttgart, Germany
- * E-mail:
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Seo EJ, Weibel S, Wehkamp J, Oelschlaeger TA. Construction of recombinant E. coli Nissle 1917 (EcN) strains for the expression and secretion of defensins. Int J Med Microbiol 2012; 302:276-87. [DOI: 10.1016/j.ijmm.2012.05.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 04/25/2012] [Accepted: 05/13/2012] [Indexed: 01/13/2023] Open
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Frantz AL, Bruno ME, Rogier EW, Tuna H, Cohen DA, Bondada S, Chelvarajan RL, Brandon JA, Jennings CD, Kaetzel CS. Multifactorial patterns of gene expression in colonic epithelial cells predict disease phenotypes in experimental colitis. Inflamm Bowel Dis 2012; 18:2138-48. [PMID: 23070952 PMCID: PMC3476470 DOI: 10.1002/ibd.22923] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 01/27/2012] [Indexed: 12/19/2022]
Abstract
BACKGROUND The pathogenesis of inflammatory bowel disease (IBD) is complex and the need to identify molecular biomarkers is critical. Epithelial cells play a central role in maintaining intestinal homeostasis. We previously identified five "signature" biomarkers in colonic epithelial cells (CEC) that are predictive of disease phenotype in Crohn's disease. Here we investigate the ability of CEC biomarkers to define the mechanism and severity of intestinal inflammation. METHODS We analyzed the expression of RelA, A20, pIgR, tumor necrosis factor (TNF), and macrophage inflammatory protein (MIP)-2 in CEC of mice with dextran sodium sulfate (DSS) acute colitis or T-cell-mediated chronic colitis. Factor analysis was used to combine the five biomarkers into two multifactorial principal components (PCs). PC scores for individual mice were correlated with disease severity. RESULTS For both colitis models, PC1 was strongly weighted toward RelA, A20, and pIgR, and PC2 was strongly weighted toward TNF and MIP-2, while the contributions of other biomarkers varied depending on the etiology of inflammation. Disease severity was correlated with elevated PC2 scores in DSS colitis and reduced PC1 scores in T-cell transfer colitis. Downregulation of pIgR was a common feature observed in both colitis models and was associated with altered cellular localization of pIgR and failure to transport IgA. CONCLUSIONS A multifactorial analysis of epithelial gene expression may be more informative than examining single gene responses in IBD. These results provide insight into the homeostatic and proinflammatory functions of CEC in IBD pathogenesis and suggest that biomarker analysis could be useful for evaluating therapeutic options for IBD patients.
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Affiliation(s)
- Aubrey L. Frantz
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky
| | - Maria E.C. Bruno
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky
| | - Eric W. Rogier
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky
| | - Halide Tuna
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky
| | - Donald A. Cohen
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky
| | - Subbarao Bondada
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky
| | - R. Lakshman Chelvarajan
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky
| | - J. Anthony Brandon
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky
| | - C. Darrell Jennings
- Department of Pathology and Laboratory Medicine, University of Kentucky, Lexington, Kentucky
| | - Charlotte S. Kaetzel
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky
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Chang CT, Tsai CN, Tang CY, Chen CH, Lian JH, Hu CY, Tsai CL, Chao A, Lai CH, Wang TH, Lee YS. Mixed sequence reader: a program for analyzing DNA sequences with heterozygous base calling. ScientificWorldJournal 2012; 2012:365104. [PMID: 22778697 PMCID: PMC3385616 DOI: 10.1100/2012/365104] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Accepted: 04/01/2012] [Indexed: 01/21/2023] Open
Abstract
The direct sequencing of PCR products generates heterozygous base-calling fluorescence chromatograms that are useful for identifying single-nucleotide polymorphisms (SNPs), insertion-deletions (indels), short tandem repeats (STRs), and paralogous genes. Indels and STRs can be easily detected using the currently available Indelligent or ShiftDetector programs, which do not search reference sequences. However, the detection of other genomic variants remains a challenge due to the lack of appropriate tools for heterozygous base-calling fluorescence chromatogram data analysis. In this study, we developed a free web-based program, Mixed Sequence Reader (MSR), which can directly analyze heterozygous base-calling fluorescence chromatogram data in .abi file format using comparisons with reference sequences. The heterozygous sequences are identified as two distinct sequences and aligned with reference sequences. Our results showed that MSR may be used to (i) physically locate indel and STR sequences and determine STR copy number by searching NCBI reference sequences; (ii) predict combinations of microsatellite patterns using the Federal Bureau of Investigation Combined DNA Index System (CODIS); (iii) determine human papilloma virus (HPV) genotypes by searching current viral databases in cases of double infections; (iv) estimate the copy number of paralogous genes, such as β-defensin 4 (DEFB4) and its paralog HSPDP3.
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Affiliation(s)
- Chun-Tien Chang
- Department of Computer Science, National Tsing Hua University, Hsin-Chu, Taiwan
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Olfactomedin-4 is a glycoprotein secreted into mucus in active IBD. J Crohns Colitis 2012; 6:425-34. [PMID: 22398066 DOI: 10.1016/j.crohns.2011.09.013] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 09/28/2011] [Accepted: 09/28/2011] [Indexed: 02/08/2023]
Abstract
BACKGROUND Olfactomedin-4 (OLFM4) is a glycoprotein characteristic of intestinal stem cells and apparently involved in mucosal defense of the stomach and colon. Here we studied its expression, regulation and function in IBD. METHODS The expression of OLFM4, mucins Muc1 and Muc2, the goblet cell differentiation factor Hath1 and the proinflammatory cytokine IL-8 was measured in inflamed or noninflamed colon in IBD patients and controls. OLFM4 protein was located by immunohistochemistry, quantified by Dot Blot and its binding capacity to defensins HBD1-3 was investigated. The influence of bacteria with or without the Notch blocker dibenzazepine (DBZ) and of several cytokines on OLFM4 expression was determined in LS174T cells. RESULTS OLFM4 mRNA and protein were significantly upregulated in inflamed CD (4.3 and 1.7-fold) and even more pronounced in UC (24.8 and 3.7-fold). OLFM4 expression was correlated to IL-8 but not to Hath1. In controls immunostaining was restricted to the lower crypts but in inflamed IBD it expanded up to the epithelial surface including the mucus. OLFM4 bound to HBD1-3 without profoundly inactivating these defensins. In LS174T-cells OLFM4 mRNA was significantly augmented after incubation with Escherichia coli K12, Escherichia coli Nissle and Bacteroides vulgatus. DBZ downregulated OLFM4 expression and blocked bacterial induction whereas IL-22 but not TNF-α was stimulatory. CONCLUSIONS OLFM4 is overexpressed in active IBD and secreted into mucus. The induction is triggered by bacteria through the Notch pathway and also by the cytokine IL-22. OLFM4 seems to be of functional relevance in IBD as a mucus component, possibly by binding defensins.
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Abstract
The pathogenetic mechanisms that cause the two types of inflammatory bowel disease (IBD), Crohn's disease (CD) and ulcerative colitis (UC), are still under investigation. Nevertheless, there is broad agreement that luminal microbes are of particular relevance in the development of these conditions. In recent years, increasing evidence has shown that defects in the innate immunity are at the centre of both types of IBD. The innate intestinal barrier is provided by the epithelium which secretes antimicrobial peptides (so-called defensins) that are retained in the mucus layer. In ileal CD, the alpha-defensins are lacking owing to several Paneth cell defects. In colonic CD, the expression of beta-defensins is inadequate. This may be related to downregulation of the transcription factor peroxisome proliferator-activated receptor-gamma and in some cohorts is associated with a reduced HBD2 gene copy number. In UC, the mucus layer, which protects the host from the enormous amounts of luminal microbes, is defective. This is accompanied by an insufficient differentiation from intestinal stem cells towards goblet cells. All these disturbances in the gut barrier shift the balance from epithelial defence towards bacterial offence. The current treatment for CD and UC is based on suppression of this secondary inflammatory process. In future, patients may benefit from new therapeutic approaches stimulating the protective innate immune system.
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Affiliation(s)
- M Gersemann
- Department of Internal Medicine I, Robert Bosch Hospital, Stuttgart Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart
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Abstract
Defensins are small, multifunctional cationic peptides. They typically contain six conserved cysteines whose three intramolecular disulfides stabilize a largely β-sheet structure. This review of human α-defensins begins by describing their evolution, including their likely relationship to the Big Defensins of invertebrates, and their kinship to the β-defensin peptides of many if not all vertebrates, and the θ-defensins found in certain non-human primates. We provide a short history of the search for leukocyte-derived microbicidal molecules, emphasizing the roles played by luck (good), preconceived notions (mostly bad), and proper timing (essential). The antimicrobial, antiviral, antitoxic, and binding properties of human α-defensins are summarized. The structural features of α-defensins are described extensively and their functional contributions are assessed. The properties of HD6, an enigmatic Paneth cell α-defensin, are contrasted with those of the four myeloid α-defensins (HNP1-4) and of HD5, the other α-defensin of human Paneth cells. The review ends with a decalogue that may assist researchers or students interested in α-defensins and related aspects of neutrophil function.
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Affiliation(s)
- Robert I Lehrer
- Department of Medicine and Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1688, USA.
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Gersemann M, Stange EF, Wehkamp J. From intestinal stem cells to inflammatory bowel diseases. World J Gastroenterol 2011; 17:3198-203. [PMID: 21912468 PMCID: PMC3158395 DOI: 10.3748/wjg.v17.i27.3198] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 02/09/2011] [Accepted: 02/16/2011] [Indexed: 02/06/2023] Open
Abstract
The pathogenesis of both entities of inflammatory bowel disease (IBD), namely Crohn’s disease (CD) and ulcerative colitis (UC), is still complex and under investigation. The importance of the microbial flora in developing IBD is beyond debate. In the last few years, the focus has changed from adaptive towards innate immunity. Crohn’s ileitis is associated with a deficiency of the antimicrobial shield, as shown by a reduced expression and secretion of the Paneth cell defensin HD5 and HD6, which is related to a Paneth cell differentiation defect mediated by a diminished expression of the Wnt transcription factor TCF4. In UC, the protective mucus layer, acting as a physical and chemical barrier between the gut epithelium and the luminal microbes, is thinner and in part denuded as compared to controls. This could be caused by a missing induction of the goblet cell differentiation factors Hath1 and KLF4 leading to immature goblet cells. This defective Paneth and goblet cell differentiation in Crohn’s ileitis and UC may enable the luminal microbes to invade the mucosa and trigger the inflammation. The exact molecular mechanisms behind ileal CD and also UC must be further clarified, but these observations could give rise to new therapeutic strategies based on a stimulation of the protective innate immune system.
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Abstract
Interaction between vitamin D and the immune system has been recognized for many years, but its relevance to normal human physiology has only become evident in the past 5 years. Studies of innate immune responses to pathogens such as Mycobacterium tuberculosis have shown that pathogen-recognition receptor-mediated activation of localized vitamin D metabolism and signaling is a key event associated with infection. Vitamin D, acting in an intracrine fashion, is able to induce expression of antibacterial proteins and enhance the environment in which they function. The net effect of these actions is to support increased bacterial killing in a variety of cell types. The efficacy of such a response is highly dependent on vitamin D status; in other words, the availability of circulating 25-hydroxyvitamin D for intracrine conversion to active 1,25-dihydroxyvitamin D by the enzyme 25-hydroxyvitamin D-1α-hydroxylase. The potential importance of this mechanism as a determinant of human disease is underlined by increasing awareness of vitamin D insufficiency across the globe. This Review will explore the molecular and cellular systems associated with antibacterial responses to vitamin D in different tissues and possible consequences of such a response for the prevention and treatment of human immune disorders.
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Affiliation(s)
- Martin Hewison
- Department of Orthopaedic Surgery, Room 410D, Orthopaedic Hospital Research Center, 615 Charles E. Young Drive South, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA 90095, USA.
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Cunningham MF, Docherty NG, Coffey JC, Burke JP, O'Connell PR. Postsurgical recurrence of ileal Crohn's disease: an update on risk factors and intervention points to a central role for impaired host-microflora homeostasis. World J Surg 2011; 34:1615-26. [PMID: 20195604 DOI: 10.1007/s00268-010-0504-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND A pressing need exists to identify factors that predispose to recurrence after terminal ileal resection for Crohn's disease (CD) and to determine effective prophylactic strategies. This review presents an up-to-date summary of the literature in the field and points to a role for bacterial overproliferation in recurrence. METHODS The literature (Medline, Embase, and the Cochrane Library, 1971-2009) on ileal CD and postoperative recurrence was searched, and 528 relevant articles were identified and reviewed. RESULTS Smoking is a key independent risk factor for recurrence. NOD2/CARD15 polymorphisms and penetrating phenotype are associated with aggressive disease and higher reoperation rates. Age at diagnosis, disease duration, gender, and family history are inconsistent predictors of recurrence. Prophylactic 5-aminosalicylic acid therapy and nitromidazole antibiotics are beneficial. Combination therapies with immunosuppressants are also effective. Anti-TNFalpha-based regimens show benefit but the evidence base is small. Corticosteroid, interleukin-10, and probiotic therapies are not effective. Wider, stapled anastomotic configurations are associated with reduced recurrence rates. Strictureplasty and laparoscopic approaches have similar long-term recurrence rates to open resection techniques. Length of resection and presence of microscopic disease at resection margins do not influence recurrence. A lack of consensus exists regarding whether the presence of granulomas or plexitis affects outcome. CONCLUSIONS Current evidence points to defects in mucosal immunity and intestinal dysbiosis of either innate (NOD2/CARD15) or induced (smoking) origin in postoperative CD recurrence. Prophylactic strategies should aim to limit dysbiosis (antibiotics, side-to-side anastomoses) or prevent downstream chronic inflammatory sequelae (anti-inflammatory, immunosuppressive, and immunomodulatory therapy).
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Affiliation(s)
- Michael F Cunningham
- Surgical Professorial Unit, St Vincent's University Hospital, Elm Park, Dublin 4, Ireland
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Kozar RA, Santora RJ, Poindexter BJ, Milner SM, Bick RJ. Alterations in content and localization of defensins in rat ileum and jejunum following ischemia-reperfusion. Specific peptides, in specific places, for specific jobs? EPLASTY 2011; 11:e8. [PMID: 21369366 PMCID: PMC3044598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To determine alterations in quantities and distributions of natural antimicrobials following ischemia-reperfusion injury. We hypothesized that these compounds would be upregulated in areas of small intestine where changes in permeability and cellular disruption were likely and where protective mechanisms would be initiated. METHODS Rats with ischemia-reperfusion underwent superior mesenteric artery clamping and reperfusion. Shams were subjected to laparotomy but no clamping. Ileum and jejunum were harvested and sectioned, and subjected to fluorescence deconvolution microscopy for determinations of content and localization of rat beta defensins, 1, 2, 3; rat neutrophil protein-1; and cathelicidin LL-37. Modeling was performed to determine cellular location of antimicrobials. RESULTS Ischemia-reperfusion increased neutrophil defensin alpha (RNP-1) in jejunum; rat beta defensin 1 was increased 2-fold in ileal mucosa and slightly reduced in jejunal mucosa; rat beta defensin 2 was reduced by ischemia-reperfusion in ileum, but slightly increased in jejunum; rat beta defensin 3 was concentrated in the muscularis externa and myenteric plexus of the jejunum; ischemia-reperfusion did not alter cathelicidin LL-37 content in the small intestine, although a greater concentration was seen in jejunum compared with ileum. CONCLUSION Ischemia-reperfusion injury caused changes in antimicrobial content in defined areas, and these different regulations might reflect the specific roles of jejunum versus ileum.
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Affiliation(s)
| | | | | | - Stephen M. Milner
- cJohns Hopkins Burn Center, Johns Hopkins University School of Medicine, Baltimore, Md
| | - Roger J. Bick
- bPathology, University of Texas Medical School at Houston, Tx,Correspondence:
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Salim SY, Söderholm JD. Importance of disrupted intestinal barrier in inflammatory bowel diseases. Inflamm Bowel Dis 2011; 17:362-81. [PMID: 20725949 DOI: 10.1002/ibd.21403] [Citation(s) in RCA: 424] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Accepted: 06/01/2010] [Indexed: 12/12/2022]
Abstract
The current paradigm of inflammatory bowel diseases (IBD), both Crohn's disease (CD) and ulcerative colitis (UC), involves the interaction between environmental factors in the intestinal lumen and inappropriate host immune responses in genetically predisposed individuals. The intestinal mucosal barrier has evolved to maintain a delicate balance between absorbing essential nutrients while preventing the entry and responding to harmful contents. In IBD, disruptions of essential elements of the intestinal barrier lead to permeability defects. These barrier defects exacerbate the underlying immune system, subsequently resulting in tissue damage. The epithelial phenotype in active IBD is very similar in CD and UC. It is characterized by increased secretion of chloride and water, leading to diarrhea, increased permeability via both the transcellular and paracellular routes, and increased apoptosis of epithelial cells. The main cytokine that seems to drive these changes is tumor necrosis factor alpha in CD, whereas interleukin (IL)-13 may be more important in UC. Therapeutic restoration of the mucosal barrier would provide protection and prevent antigenic overload due to intestinal "leakiness." Here we give an overview of the key players of the intestinal mucosal barrier and review the current literature from studies in humans and human systems on mechanisms underlying mucosal barrier dysfunction in IBD.
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Affiliation(s)
- Sa'ad Y Salim
- Department of Clinical and Experimental Medicine, Division of Surgery and Clinical Oncology, Faculty of Health Sciences, Linköping University, Linköping, Sweden
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Lapis K. [Barrier- and autophagic functions of the intestinal epithelia: role of disturbances in the pathogenesis of Crohn's disease]. Orv Hetil 2010; 151:1645-55. [PMID: 20860961 DOI: 10.1556/oh.2010.28942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Crohn's disease is a widely known debilitating chronic inflammatory disease, mostly affecting terminal ileum and/or colon. Epidemiological, familial and twin studies suggest that genetic factors play an important role in susceptibility to the disease. Clinical observations suggest that ill-defined environmental factors also play a part. Advances in molecular genotyping technology, statistical methodologies, bioinformatics and the combined use of them in genome wide scanning and association studies resulted in the identification of more than 30 susceptibility genes and loci associated with Crohn's disease and revealed and highlighted a number of new previously unsuspected pathways playing a role in the pathogenesis of Crohn's disease. Close association of the disease with polymorphisms in the genes encoding the pattern recognition receptors particularly the NOD2 protein, the Wnt pathway transcription factor Tcf4 (also known as TCFL2) and the autophagic regulator ATG16L1 have been found. The polymorphisms involved are associated with decreased defensin production (defensin deficiency) which can lead to changes in the composition of the commensal microbial flora, defects in the intestinal barrier functions and bacterial invasion of the mucosa. Other recently recognized consequences of the polymorphisms involving the genes encoding NOD2 and ATG16L1 proteins are that the truncated NOD2 protein is unable to induce autophagy and this protein, just like the ATG16L1 T300A mutant protein, leads to failure adequately to destroy phagocytosed bacteria. The consequence is persisting low level infection, chronic intestinal inflammation, tissue injury and the clinical symptoms of the disease. Thus, Crohn's disease can be seen to be caused by defects in the innate immune defense, in particular defects in bacterial processing and clearance. The accumulated evidence suggests that Crohn's disease is associated with an exaggerated adaptive immune response to the persisting intestinal microbes in genetically susceptible hosts. Intervention in these circumstances should probably be geared to strengthening of the innate immune responses rather than simple attempts to suppress adaptive immunity.
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Affiliation(s)
- Károly Lapis
- Semmelweis Egyetem, Altalános Orvostudományi Kar I. Patológiai és Kísérleti Rákkutató Intézet Budapest.
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Lagishetty V, Misharin AV, Liu NQ, Lisse TS, Chun RF, Ouyang Y, McLachlan SM, Adams JS, Hewison M. Vitamin D deficiency in mice impairs colonic antibacterial activity and predisposes to colitis. Endocrinology 2010; 151:2423-32. [PMID: 20392825 PMCID: PMC2875827 DOI: 10.1210/en.2010-0089] [Citation(s) in RCA: 189] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Accepted: 03/15/2010] [Indexed: 02/07/2023]
Abstract
Vitamin D insufficiency is a global health issue. Although classically associated with rickets, low vitamin D levels have also been linked to aberrant immune function and associated health problems such as inflammatory bowel disease (IBD). To test the hypothesis that impaired vitamin D status predisposes to IBD, 8-wk-old C57BL/6 mice were raised from weaning on vitamin D-deficient or vitamin D-sufficient diets and then treated with dextran sodium sulphate (DSS) to induce colitis. Vitamin D-deficient mice showed decreased serum levels of precursor 25-hydroxyvitamin D(3) (2.5 +/- 0.1 vs. 24.4 +/- 1.8 ng/ml) and active 1,25-dihydroxyvitamin D(3) (28.8 +/- 3.1 vs. 45.6 +/- 4.2 pg/ml), greater DSS-induced weight loss (9 vs. 5%), increased colitis (4.71 +/- 0.85 vs. 1.57 +/- 0.18), and splenomegaly relative to mice on vitamin D-sufficient chow. DNA array analysis of colon tissue (n = 4 mice) identified 27 genes consistently (P < 0.05) up-regulated or down-regulated more than 2-fold in vitamin D-deficient vs. vitamin D-sufficient mice, in the absence of DSS-induced colitis. This included angiogenin-4, an antimicrobial protein involved in host containment of enteric bacteria. Immunohistochemistry confirmed that colonic angiogenin-4 protein was significantly decreased in vitamin D-deficient mice even in the absence of colitis. Moreover, the same animals showed elevated levels (50-fold) of bacteria in colonic tissue. These data show for the first time that simple vitamin D deficiency predisposes mice to colitis via dysregulated colonic antimicrobial activity and impaired homeostasis of enteric bacteria. This may be a pivotal mechanism linking vitamin D status with IBD in humans.
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Affiliation(s)
- Venu Lagishetty
- Room 410D, Orthopaedic Hospital Research Center, University of California Los Angeles, Los Angeles, California 90095, USA
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Lapara NJ, Kelly BL. Suppression of LPS-induced inflammatory responses in macrophages infected with Leishmania. JOURNAL OF INFLAMMATION-LONDON 2010; 7:8. [PMID: 20205812 PMCID: PMC2824668 DOI: 10.1186/1476-9255-7-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Accepted: 02/02/2010] [Indexed: 07/01/2024]
Abstract
Background Chronic inflammation activated by macrophage innate pathogen recognition receptors such as TLR4 can lead to a range of inflammatory diseases, including atherosclerosis, Crohn's disease, arthritis and cancer. Unlike many microbes, the kinetoplastid protozoan pathogen Leishmania has been shown to avoid and even actively suppress host inflammatory cytokine responses, such as LPS-induced IL-12 production. The nature and scope of Leishmania-mediated inflammatory cytokine suppression, however, is not well characterized. Advancing our knowledge of such microbe-mediated cytokine suppression may provide new avenues for therapeutic intervention in inflammatory disease. Methods We explored the kinetics of a range of cytokine and chemokine responses in primary murine macrophages stimulated with LPS in the presence versus absence of two clinically distinct species of Leishmania using sensitive multiplex cytokine analyses. To confirm that these effects were parasite-specific, we compared the effects of Leishmania uptake on LPS-induced cytokine expression with uptake of inert latex beads. Results Whilst Leishmania uptake alone did not induce significant levels of any cytokine analysed in this study, Leishmania uptake in the presence of LPS caused parasite-specific suppression of certain LPS-induced pro-inflammatory cytokines, including IL-12, IL-17 and IL-6. Interestingly, L. amazonensis was generally more suppressive than L. major. We also found that other LPS-induced proinflammatory cytokines, such as IL-1α, TNF-α and the chemokines MIP-1α and MCP-1 and also the anti-inflammatory cytokine IL-10, were augmented during Leishmania uptake, in a parasite-specific manner. Conclusions During uptake by macrophages, Leishmania evades the activation of a broad range of cytokines and chemokines. Further, in the presence of a strong inflammatory stimulus, Leishmania suppresses certain proinflammatory cytokine responses in a parasite-specific manner, however it augments the production of other proinflammatory cytokines. Our findings highlight the complexity of inflammatory cytokine signalling regulation in the context of the macrophage and Leishmania interaction and confirm the utility of the Leishmania/macrophage infection model as an experimental system for further studies of inflammatory regulation. Such studies may advance the development of therapies against inflammatory disease.
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Affiliation(s)
- Nicholas J Lapara
- Department of Microbiology Immunology and Parasitology, LSU Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112, USA.
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Lapis K. Role of antimicrobial peptides (AMP) and pattern recognition receptors (PRR) in the intestinal mucosa homeostasis. Orv Hetil 2009; 150:2146-9. [DOI: 10.1556/oh.2009.28737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Homeostasis and integrity of bowel mucosa is assured by well controlled mechanical, biochemical and immunological mechanisms. First line of defense is presented by the antimicrobial peptides (AMP), which form a continuous layer on the bowel surface, produced by intestinal specific (Paneth) and non-specific epithelial cells. AMPs have a significant antimicrobial, antifungal and antiviral, as well as immunomodulatory effects. Next line of defense is the pattern recognition receptors (PRR), which allows identifying conservative molecular patterns of different pathogens, and starts antimicrobial and inflammatory mechanisms through gene-expression induction. We review the most recent knowledge and studies concerning these mechanisms.
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Affiliation(s)
- Károly Lapis
- Semmelweis Egyetem, Általános Orvostudományi Kar I. Patológiai és Kísérleti Rákkutató Intézet Budapest Üllői út 26. 1085
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Auvynet C, Rosenstein Y. Multifunctional host defense peptides: antimicrobial peptides, the small yet big players in innate and adaptive immunity. FEBS J 2009; 276:6497-508. [PMID: 19817855 DOI: 10.1111/j.1742-4658.2009.07360.x] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The term 'antimicrobial peptides' refers to a large number of peptides first characterized on the basis of their antibiotic and antifungal activities. In addition to their role as endogenous antibiotics, antimicrobial peptides, also called host defense peptides, participate in multiple aspects of immunity (inflammation, wound repair, and regulation of the adaptive immune system) as well as in maintaining homeostasis. The possibility of utilizing these multifunctional molecules to effectively combat the ever-growing group of antibiotic-resistant pathogens has intensified research aimed at improving their antibiotic activity and therapeutic potential, without the burden of an exacerbated inflammatory response, but conserving their immunomodulatory potential. In this minireview, we focus on the contribution of small cationic antimicrobial peptides - particularly human cathelicidins and defensins - to the immune response and disease, highlighting recent advances in our understanding of the roles of these multifunctional molecules.
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Affiliation(s)
- Constance Auvynet
- Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Cuernavaca, Mor. Mexico
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Tozer PJ, Whelan K, Phillips RKS, Hart AL. Etiology of perianal Crohn's disease: role of genetic, microbiological, and immunological factors. Inflamm Bowel Dis 2009; 15:1591-8. [PMID: 19637358 DOI: 10.1002/ibd.21026] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Perianal fistulation is a common complication of Crohn's disease (CD). Fistulating perianal CD appears to represent a distinct phenotype of CD, separate from luminal fistulating disease, with differing disease behavior and which often requires different therapeutic strategies. The etiology of Crohn's perianal fistulae appears to have genetic, microbiological, and immunological components. Relationships with IBD5, which codes for the organic/cation transporter and IRGM, important in the autophagy pathway, have been identified but further genetic associations remain elusive. The partially efficacious use of antibiotics and fecal diversion imply a microbiological component and, similarly, the partial efficacy of immunosuppressants and anti-tumor necrosis factor alpha (TNFalpha) treatments suggest not only that an immunological process is taking place, but also that microbiota alone cannot account for the pathogenesis. Recent work implicates failures in the tissue injury/repair process with myofibroblasts, matrix metalloproteinases, and an epithelial-to-mesenchymal transition being possible culprits. We examine these areas in a review of the current understanding of the etiology of Crohn's perianal fistulae.
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Fierabracci A. Unravelling autoimmune pathogenesis by screening random peptide libraries with human sera. Immunol Lett 2009; 124:35-43. [PMID: 19375456 DOI: 10.1016/j.imlet.2009.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 04/01/2009] [Accepted: 04/04/2009] [Indexed: 12/20/2022]
Abstract
The incidence of autoimmunity is increasing worldwide. The long preclinical period of autoimmune disorders is characterised by an enhanced exposure over time of autoreactive T cells to an increased number of autoantigenic determinants and autoantibodies production. The discovery of novel autoimmune-disease related epitopes is a task that remains extremely challenging in order to establish predictive and preventive strategies of the disease onset. In this Opinion article we highlight the contribution of screening combinatorial random peptide libraries with patients sera in unravelling the etiopathogenesis of autoimmunity.
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Affiliation(s)
- Alessandra Fierabracci
- Autoimmunity and Organ Regeneration Laboratory, Ospedale Pediatrico Bambino Gesu', Research Institute, Piazza S. Onofrio 4, 00165 Rome, Italy.
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