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Kumar A, Chatterjee I, Gujral T, Alakkam A, Coffing H, Anbazhagan AN, Borthakur A, Saksena S, Gill RK, Alrefai WA, Dudeja PK. Activation of Nuclear Factor-κB by Tumor Necrosis Factor in Intestinal Epithelial Cells and Mouse Intestinal Epithelia Reduces Expression of the Chloride Transporter SLC26A3. Gastroenterology 2017; 153:1338-1350.e3. [PMID: 28823863 PMCID: PMC5669803 DOI: 10.1053/j.gastro.2017.08.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 07/26/2017] [Accepted: 08/02/2017] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Diarrhea associated with inflammatory bowel diseases has been associated with increased levels of inflammatory cytokines, including tumor necrosis factor (TNF). The intestinal mucosa of patients with inflammatory bowel diseases has reduced expression of solute carrier family 26 member 3 (SLC26A3, also called DRA). We investigated whether TNF directly affects expression of DRA in human intestinal epithelial cells (IECs) and in the intestines of mice, and studied the mechanisms of these effects. METHODS We performed quantitative reverse transcription polymerase chain reaction, immunofluorescence, and immunoblot analyses in Caco-2, HT-29, and T-84 cells human IECs cultured in 2 or 3 dimensions with or without TNF (50 ng/mL for 6-24 hours). We purified nuclear extracts and quantified nuclear factor-κB (NF-κB) activation and DNA binding. We isolated intestinal crypts from C57BL/6 mice, cultured enteroids, incubated these with TNF (50 ng/mL, 24 hours), and quantified messenger RNAs. DRA-mediated exchange of Cl- for HCO3- was measured by uptake of 125I. Expression of the NF-κB inhibitor α (IkBa) was knocked down in Caco-2 cells with small interfering RNAs. Activation of NF-κB in response to TNF was measured by luciferase reporter assays; binding of the NF-κB subunit p65 in cells was analyzed in chromatin immunoprecipitation assays. DRA promoter activity was measured in a luciferase reporter assay. C57BL/6 mice were injected with TNF (5 μg/mouse for 3-6 hours) or vehicle (control); intestines were collected and analyzed by immunofluorescence, or RNA and protein were collected from the mucosa. RESULTS Incubation of IECs with TNF reduced expression of DRA. Knockdown of NF-κB inhibitor α in IECs led to nuclear translocation of the NF-κB subunit p65 and reduced levels of DRA messenger RNA and protein. Expression of a transgene encoding p65 or p50 in IECs led to significant reductions in the promoter activity of DRA and its expression. In chromatin immunoprecipitation assays, p65 bound directly to the promoter of DRA, at the regions of -935 to -629 and -375 to -84. Injection of mice with TNF or incubation of crypt-derived enteroids with TNF reduced their expression of DRA messenger RNA and protein. CONCLUSIONS In human IECs and intestinal tissues from mice, we found TNF to activate NF-κB, which reduced expression of the Cl- / HCO3- exchanger DRA (SLC26A3), via direct binding to the promoter of DRA. This pathway is an important therapeutic target for inflammatory bowel disease-associated diarrhea.
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Affiliation(s)
- Anoop Kumar
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Ishita Chatterjee
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Tarunmeet Gujral
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Anas Alakkam
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Hayley Coffing
- Department of Microbiology and Immunology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Arivarasu N Anbazhagan
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Alip Borthakur
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Seema Saksena
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| | - Ravinder K Gill
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Waddah A Alrefai
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| | - Pradeep K Dudeja
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois.
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Inhibition of corticotropin-releasing hormone receptor 1 and activation of receptor 2 protect against colonic injury and promote epithelium repair. Sci Rep 2017; 7:46616. [PMID: 28492284 PMCID: PMC5425914 DOI: 10.1038/srep46616] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 03/21/2017] [Indexed: 12/16/2022] Open
Abstract
Maternal separation (MS) in neonates can lead to intestinal injury. MS in neonatal mice disrupts mucosal morphology, induces colonic inflammation and increases trans-cellular permeability. Several studies indicate that intestinal epithelial stem cells are capable of initiating gut repair in a variety of injury models but have not been reported in MS. The pathophysiology of MS-induced gut injury and subsequent repair remains unclear, but communication between the brain and gut contribute to MS-induced colonic injury. Corticotropin-releasing hormone (CRH) is one of the mediators involved in the brain–gut axis response to MS-induced damage. We investigated the roles of the CRH receptors, CRHR1 and CRHR2, in MS-induced intestinal injury and subsequent repair. To distinguish their specific roles in mucosal injury, we selectively blocked CRHR1 and CRHR2 with pharmacological antagonists. Our results show that in response to MS, CRHR1 mediates gut injury by promoting intestinal inflammation, increasing gut permeability, altering intestinal morphology, and modulating the intestinal microbiota. In contrast, CRHR2 activates intestinal stem cells and is important for gut repair. Thus, selectively blocking CRHR1 and promoting CRHR2 activity could prevent the development of intestinal injuries and enhance repair in the neonatal period when there is increased risk of intestinal injury such as necrotizing enterocolitis.
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Merga YJ, O'Hara A, Burkitt MD, Duckworth CA, Probert CS, Campbell BJ, Pritchard DM. Importance of the alternative NF-κB activation pathway in inflammation-associated gastrointestinal carcinogenesis. Am J Physiol Gastrointest Liver Physiol 2016; 310:G1081-90. [PMID: 27102559 DOI: 10.1152/ajpgi.00026.2016] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/17/2016] [Indexed: 02/07/2023]
Abstract
Chronic inflammation is a common factor in the development of many gastrointestinal malignancies. Examples include inflammatory bowel disease predisposing to colorectal cancer, Barrett's esophagus as a precursor of esophageal adenocarcinoma, and Helicobacter pylori-induced gastric cancer. The classical activation pathway of NF-κB signaling has been identified as regulating several sporadic and inflammation-associated gastrointestinal tract malignancies. Emerging evidence suggests that the alternative NF-κB signaling pathway also exerts a distinct influence on these processes. This review brings together current knowledge of the role of the alternative NF-κB signaling pathway in the gastrointestinal tract, with a particular emphasis on inflammation-associated cancer development.
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Affiliation(s)
- Yvette J Merga
- Gastroenterology Research Unit, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Adrian O'Hara
- Gastroenterology Research Unit, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Michael D Burkitt
- Gastroenterology Research Unit, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Carrie A Duckworth
- Gastroenterology Research Unit, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Christopher S Probert
- Gastroenterology Research Unit, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Barry J Campbell
- Gastroenterology Research Unit, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - D Mark Pritchard
- Gastroenterology Research Unit, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
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Zhu H, Wan X, Li J, Han L, Bo X, Chen W, Lu C, Shen Z, Xu C, Chen L, Yu C, Xu G. Computational Prediction and Validation of BAHD1 as a Novel Molecule for Ulcerative Colitis. Sci Rep 2015; 5:12227. [PMID: 26183847 PMCID: PMC4505333 DOI: 10.1038/srep12227] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 06/19/2015] [Indexed: 01/09/2023] Open
Abstract
Ulcerative colitis (UC) is a common inflammatory bowel disease (IBD) producing
intestinal inflammation and tissue damage. The precise aetiology of UC remains
unknown. In this study, we applied a rank-based expression profile comparative
algorithm, gene set enrichment analysis (GSEA), to evaluate the expression profiles
of UC patients and small interfering RNA (siRNA)-perturbed cells to predict proteins
that might be essential in UC from publicly available expression profiles. We used
quantitative PCR (qPCR) to characterize the expression levels of those genes
predicted to be the most important for UC in dextran sodium sulphate (DSS)-induced
colitic mice. We found that bromo-adjacent homology domain (BAHD1), a novel
heterochromatinization factor in vertebrates, was the most downregulated gene. We
further validated a potential role of BAHD1 as a regulatory factor for inflammation
through the TNF signalling pathway in vitro. Our findings indicate that
computational approaches leveraging public gene expression data can be used to infer
potential genes or proteins for diseases, and BAHD1 might act as an indispensable
factor in regulating the cellular inflammatory response in UC.
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Affiliation(s)
- Huatuo Zhu
- Department of Gastroenterology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Xingyong Wan
- Department of Gastroenterology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Jing Li
- Department of Gastroenterology, Peking University People's Hospital, Beijing, China
| | - Lu Han
- Beijing Institute of Radiation Medicine, Beijing, China
| | - Xiaochen Bo
- Beijing Institute of Radiation Medicine, Beijing, China
| | - Wenguo Chen
- Department of Gastroenterology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Chao Lu
- Department of Gastroenterology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Zhe Shen
- Department of Gastroenterology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Chenfu Xu
- Department of Gastroenterology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Lihua Chen
- Department of Gastroenterology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Chaohui Yu
- Department of Gastroenterology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Guoqiang Xu
- Department of Gastroenterology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
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Adler J, Punglia DR, Dillman JR, Polydorides AD, Dave M, Al-Hawary MM, Platt JF, McKenna BJ, Zimmermann EM. Computed tomography enterography findings correlate with tissue inflammation, not fibrosis in resected small bowel Crohn's disease. Inflamm Bowel Dis 2012; 18:849-56. [PMID: 21710535 DOI: 10.1002/ibd.21801] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 05/20/2011] [Indexed: 12/13/2022]
Abstract
BACKGROUND It has become commonplace to categorize small intestinal Crohn's disease (CD) as "active" vs. "inactive" or "inflammatory" vs. "fibrotic" based on computed tomography enterography (CTE) findings. Data on histologic correlates of CTE findings are lacking. We aimed to compare CTE findings with histology from surgically resected specimens. We tested the hypothesis that CTE findings can distinguish tissue inflammation from fibrosis. METHODS Patients who underwent CTE within 3 months before intestinal resection for CD were retrospectively studied. Radiologists blinded to history and histology scored findings on CTE. Pathologists blinded to history and imaging scored resected histology. We compared histology with CTE findings and radiologists assessment of whether the stricture was likely "active" or "inactive." RESULTS In all, 22 patients met inclusion criteria. Inflammatory CTE findings correlated with histologic inflammation (rho = 0.52). Strictures believed to be "active" on CTE were more inflamed at histology (P = 0.0002). Strictures lacking inflammatory findings on CTE or considered "inactive" were not associated with greater histologic fibrosis or significant histologic inflammation. Upstream dilation was associated with greater tissue fibrosis in univariate (P = 0.014) but not in multivariate analysis (P = 0.53). Overall, histologic fibrosis correlated best with histologic inflammation (rho = 0.52). Strictures on CTE with the most active disease activity also had the most fibrosis on histology. CONCLUSIONS CTE findings of mesenteric hypervascularity, mucosal hyperenhancement, and mesenteric fat stranding predict tissue inflammation. However, small bowel stricture without CTE findings of inflammation does not predict the presence of tissue fibrosis. Therefore, caution should be used when using CTE criteria to predict the presence of scar tissue.
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Affiliation(s)
- Jeremy Adler
- Division of Pediatric Gastroenterology, Department of Pediatrics and Communicable Diseases, University of Michigan Health System, Ann Arbor, Michigan 48109, USA.
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Amin MR, Orenuga T, Tyagi S, Dudeja PK, Ramaswamy K, Malakooti J. Tumor necrosis factor-α represses the expression of NHE2 through NF-κB activation in intestinal epithelial cell model, C2BBe1. Inflamm Bowel Dis 2011; 17:720-31. [PMID: 20722069 PMCID: PMC2990806 DOI: 10.1002/ibd.21419] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Accepted: 06/09/2010] [Indexed: 12/15/2022]
Abstract
BACKGROUND High levels of proinflammatory cytokines are linked to pathogenesis of diarrhea in inflammatory bowel disease (IBD). Na(+) absorption is compromised in IBD. The studies were designed to determine the effect of tumor necrosis factor-α (TNF-α) on the expression and activity of NHE2, a Na(+) /H(+) exchanger (NHE) that is involved in transepithelial Na(+) absorption in intestinal epithelial cells. METHODS NHE2 regulation was examined in TNF-α-treated C2BBe1 cells by reverse-transcription polymerase chain reaction (RT-PCR), reporter gene assays, and Western blot analysis. NHE isoform activities were measured as ethyl-isopropyl-amiloride- and HOE694-sensitive (22) Na-uptake. In vitro and in vivo protein-DNA interactions were assessed by gel mobility shift assays and chromatin immunoprecipitation studies. RESULTS TNF-α treatment of C2BBe1 cells led to repression of NHE2 promoter activity, mRNA, and protein levels; and inhibited both NHE2 and NHE3 mediated (22) Na-uptake. 5'-deletion analysis of the NHE2 promoter-reporter constructs identified basepair -621 to -471 as the TNF-α-responsive region (TNF-RE). TNF-α activated NF-κB subunits, p50 and p65, and their DNA-binding to a putative NF-κB motif within TNF-RE. Mutations in the NF-κB motif abolished NF-κB-DNA interactions and abrogated TNF-α-induced repression. Ectopic overexpression of NF-κB resulted in repression of NHE2 expression. Two functionally distinct inhibitors of NF-κB blocked the inhibitory effect of TNF-α. CONCLUSIONS The human NHE2 isoform is a direct target of transcription factor NF-κB. TNF-α-mediated activation of NF-κB decreases the expression and activity of NHE2 in the intestinal epithelial cell line, C2BBe1. These findings implicate NF-κB in the modulation of Na(+) absorption during intestinal inflammatory conditions such as IBD where a high level of TNF-α is detected.
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Affiliation(s)
- Md Ruhul Amin
- Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, USA
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Holtmann MH, Neurath MF. From immunogenic mechanisms to novel therapeutic approaches in inflammatory bowel disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 579:227-42. [PMID: 16620022 DOI: 10.1007/0-387-33778-4_15] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Crohn's disease (CD) and ulcerative colitis (UC) are the two most common forms of chronic inflammatory bowel disease (IBD). The etiology of IBD is still unclear and should be considered as multi-factorial according to recent studies. Genetic factors seem to play a pathogenetic role as well as environmental, infectious and immulogical factors. Substantial progress, however, has been made in the understanding of the pathogenesis of IBD during the past years persuing the view, that IBD could result from disturbances of the intestinal barrier and a pathologic activation of the intestinal immune response towards luminal, bacterial antigens. This paradigm has led to the identification of key players of the intestinal immune system, which represent promising targets for novel therapeutic approaches. The objective of this chapter is to provide an overview over recent advances in the elucidation of the intestinal immune system in IBD and novel therapeutic approaches that have been derived from these results. Molecular biological techniques have revealed, that many of the established conventional antiinflammatory drugs such as salicylic acids, steroids or immunuosuppressants act at the same molecules that are the target for modern biologicals, i.e., the cytokine TNF or the transcription factor NFkappaB. This chapter, however, focusses on novel experimental approaches such as recombinant antiinflammatory cytokines, neutralizing antibodies or antisense oligonucleotides.
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Affiliation(s)
- Martin H Holtmann
- 1st Department of Medicine, Johannes-Gutenberg-University, Mainz, Germany
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Zhao D, Kuhnt-Moore S, Zeng H, Wu JS, Moyer MP, Pothoulakis C. Neurotensin stimulates IL-8 expression in human colonic epithelial cells through Rho GTPase-mediated NF-kappa B pathways. Am J Physiol Cell Physiol 2003; 284:C1397-404. [PMID: 12584113 DOI: 10.1152/ajpcell.00328.2002] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Neurotensin (NT), a neuropeptide highly expressed in the gastrointestinal tract, participates in the pathophysiology of intestinal inflammation. We recently showed that NT stimulates interleukin-8 (IL-8) expression in NCM460 nontransformed human colonic epithelial cells via both mitogen-activating protein kinase (MAPK)- and NF-kappaB-dependent pathways. However, the molecular mechanism by which NT induces expression of proinflammatory cytokines such as IL-8 has not been investigated. In this study we show that inhibition of endogenous Rho family proteins (RhoA, Rac1, and Cdc42) by their respective dominant negative mutants inhibits NT-induced IL-8 protein production and promoter activity. Western blot experiments demonstrated that NT strongly activated RhoA, Rac1, and Cdc42. Overexpression of the dominant negative mutants of RhoA, Rac1, and Cdc42 significantly inhibited NT-induced NF-kappaB-dependent reporter gene expression and NF-kappaB DNA binding activity. NT also stimulated p38 MAPK phosphorylation, and overexpression of dominant negative mutants of RhoA, Rac1, and Cdc42 did not significantly alter p38 and ERK1/2 phosphorylation in response to NT. Together, our findings indicate that NT-stimulated IL-8 expression is mediated via a Rho-dependent NF-kappaB-mediated pathway.
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Affiliation(s)
- Dezheng Zhao
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02468, USA
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