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Saha K, Subramenium Ganapathy A, Wang A, Arumugam P, Michael Morris N, Harris L, Yochum G, Koltun W, Perdew GH, Nighot M, Ma T, Nighot P. Alpha-tocopherylquinone-mediated activation of the Aryl Hydrocarbon Receptor regulates the production of inflammation-inducing cytokines and ameliorates intestinal inflammation. Mucosal Immunol 2023; 16:826-842. [PMID: 37716509 PMCID: PMC10809159 DOI: 10.1016/j.mucimm.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 09/01/2023] [Accepted: 09/09/2023] [Indexed: 09/18/2023]
Abstract
This study investigated the role of Alpha-tocopherylquinone (TQ) in regulating the intestinal immune system and the underlying mechanisms. In the experimental dextran sodium sulfate and T cell-mediated colitis models, TQ significantly reduced the mRNA levels of interleukin (IL)-6, IL-1β, IL-17A, IL-23, and tumor necrosis factor (TNF)-α and the abundance of proinflammatory macrophages, T helper (Th)17 cells, and ILC3s in the colons of wild-type mice. TQ also prevented lipopolysaccharide (LPS)-induced activation of NFκB and signal transducer and activator of transcription (Stat)-3 pathways in the human macrophage U937 cells. Pharmacological inhibition or CRISPR-Cas-9-mediated knockout of Aryl hydrocarbon Receptor (AhR) prevented the anti-inflammatory effects of TQ in the LPS-treated U937 cells. Furthermore, TQ reduced the mRNA levels of the LPS-induced pro-inflammatory cytokines in the WT but not Ahr-/- mice splenocytes. TQ also reduced IL-6R protein levels and IL-6-induced Stat-3 activation in Jurkat cells and in vitro differentiation of Th17 cells from wild-type but not Ahr-/- mice naive T cells. Additionally, TQ prevented the pro-inflammatory effects of LPS on macrophages and stimulation of T cells in human PBMCs and significantly reduced the abundance of tumor necrosis factor-α, IL-1β, and IL-6hi inflammatory macrophages and Th17 cells in surgically resected Crohn's disease (CD) tissue. Our study shows that TQ is a naturally occurring, non-toxic, and effective immune modulator that activates AhR and suppresses the Stat-3-NFκB signaling.
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Affiliation(s)
- Kushal Saha
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | | | - Alexandra Wang
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Priya Arumugam
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Nathan Michael Morris
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Leonard Harris
- Division of Colon and Rectal Surgery, Department of Surgery, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Gregory Yochum
- Division of Colon and Rectal Surgery, Department of Surgery, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Walter Koltun
- Division of Colon and Rectal Surgery, Department of Surgery, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Meghali Nighot
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Thomas Ma
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Prashant Nighot
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA.
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Ganapathy AS, Saha K, Wang A, Arumugam P, Dharmaprakash V, Yochum G, Koltun W, Nighot M, Perdew G, Thompson TA, Ma T, Nighot P. Alpha-tocopherylquinone differentially modulates claudins to enhance intestinal epithelial tight junction barrier via AhR and Nrf2 pathways. Cell Rep 2023; 42:112705. [PMID: 37393618 PMCID: PMC10528852 DOI: 10.1016/j.celrep.2023.112705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/25/2023] [Accepted: 06/12/2023] [Indexed: 07/04/2023] Open
Abstract
Defects in intestinal epithelial tight junctions (TJs) allow paracellular permeation of noxious luminal antigens and are important pathogenic factors in inflammatory bowel disease (IBD). We show that alpha-tocopherylquinone (TQ), a quinone-structured oxidation product of vitamin E, consistently enhances the intestinal TJ barrier by increasing barrier-forming claudin-3 (CLDN3) and reducing channel-forming CLDN2 in Caco-2 cell monolayers (in vitro), mouse models (in vivo), and surgically resected human colons (ex vivo). TQ reduces colonic permeability and ameliorates colitis symptoms in multiple colitis models. TQ, bifunctionally, activates both aryl hydrocarbon receptor (AhR) and nuclear factor erythroid 2-related factor 2 (Nrf2) pathways. Genetic deletion studies reveal that TQ-induced AhR activation transcriptionally increases CLDN3 via xenobiotic response element (XRE) in the CLDN3 promoter. Conversely, TQ suppresses CLDN2 expression via Nrf2-mediated STAT3 inhibition. TQ offers a naturally occurring, non-toxic intervention for enhancement of the intestinal TJ barrier and adjunct therapeutics to treat intestinal inflammation.
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Affiliation(s)
| | - Kushal Saha
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Alexandra Wang
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Priya Arumugam
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Viszwapriya Dharmaprakash
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Gregory Yochum
- Division of Colon and Rectal Surgery, Department of Surgery, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Walter Koltun
- Division of Colon and Rectal Surgery, Department of Surgery, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Meghali Nighot
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Gary Perdew
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Todd A Thompson
- University of New Mexico College of Pharmacy, Albuquerque, NM 87131, USA
| | - Thomas Ma
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Prashant Nighot
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA.
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Nighot M, Liao PL, Morris N, McCarthy D, Dharmaprakash V, Ullah Khan I, Dalessio S, Saha K, Ganapathy AS, Wang A, Ding W, Yochum G, Koltun W, Nighot P, Ma T. Long-Term Use of Proton Pump Inhibitors Disrupts Intestinal Tight Junction Barrier and Exaggerates Experimental Colitis. J Crohns Colitis 2023; 17:565-579. [PMID: 36322638 PMCID: PMC10115233 DOI: 10.1093/ecco-jcc/jjac168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Indexed: 12/03/2022]
Abstract
BACKGROUND Proton pump inhibitors [PPIs] are widely used to treat a number of gastro-oesophageal disorders. PPI-induced elevation in intragastric pH may alter gastrointestinal physiology. The tight junctions [TJs] residing at the apical intercellular contacts act as a paracellular barrier. TJ barrier dysfunction is an important pathogenic factor in inflammatory bowel disease [IBD]. Recent studies suggest that PPIs may promote disease flares in IBD patients. The role of PPIs in intestinal permeability is not clear. AIM The aim of the present study was to study the effect of PPIs on the intestinal TJ barrier function. METHODS Human intestinal epithelial cell culture and organoid models and mouse IBD models of dextran sodium sulphate [DSS] and spontaneous enterocolitis in IL-10-/- mice were used to study the role of PPIs in intestinal permeability. RESULTS PPIs increased TJ barrier permeability via an increase in a principal TJ regulator, myosin light chain kinase [MLCK] activity and expression, in a p38 MAPK-dependent manner. The PPI-induced increase in extracellular pH caused MLCK activation via p38 MAPK. Long-term PPI administration in mice exaggerated the increase in intestinal TJ permeability and disease severity in two independent models of DSS colitis and IL-10-/- enterocolitis. The TJ barrier disruption by PPIs was prevented in MLCK-/- mice. Human database studies revealed increased hospitalizations associated with PPI use in IBD patients. CONCLUSIONS Our results suggest that long-term use of PPIs increases intestinal TJ permeability and exaggerates experimental colitis via an increase in MLCK expression and activity.
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Affiliation(s)
- Meghali Nighot
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Pei-Luan Liao
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Nathan Morris
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Dennis McCarthy
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of New Mexico, Albuquerque, NM 87131, USA
| | - Viszwapriya Dharmaprakash
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Inam Ullah Khan
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Shannon Dalessio
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Kushal Saha
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | | | - Alexandra Wang
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Wei Ding
- Division of Colon and Rectal Surgery, Department of Surgery, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Gregory Yochum
- Division of Colon and Rectal Surgery, Department of Surgery, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Walter Koltun
- Division of Colon and Rectal Surgery, Department of Surgery, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Prashant Nighot
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Thomas Ma
- Division of Gastroenterology and Hepatology, Department of Medicine, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
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The ClC-2 Chloride Channel Activator, Lubiprostone, Improves Intestinal Barrier Function in Biopsies from Crohn’s Disease but Not Ulcerative Colitis Patients. Pharmaceutics 2023; 15:pharmaceutics15030811. [PMID: 36986672 PMCID: PMC10053841 DOI: 10.3390/pharmaceutics15030811] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 02/05/2023] [Accepted: 02/22/2023] [Indexed: 03/06/2023] Open
Abstract
The prostone analog, lubiprostone, is approved to manage constipation-predominant irritable bowel syndrome. Lubiprostone also protects intestinal mucosal barrier function in animal models of colitis. The aim of this study was to determine if lubiprostone improves barrier properties in isolated colonic biopsies from Crohn’s disease (CD) and ulcerative colitis (UC) patients. Sigmoid colon biopsies from healthy subjects, CD and UC patients in remission, and CD patients with active disease were mounted in Ussing chambers. Tissues were treated with lubiprostone or vehicle to determine the effects on transepithelial electrical resistance (TER), FITC-dextran 4kD (FD4) permeability, and electrogenic ion transport responses to forskolin and carbachol. Localization of the tight junction protein, occludin, was determined by immunofluorescence. Lubiprostone significantly increased ion transport across control, CD and UC remission biopsies but not active CD. Lubiprostone selectively improved TER in both CD remission and active disease biopsies but not in control or UC biopsies. The improved TER was associated with increased membrane localization of occludin. Lubiprostone selectively improved barrier properties of biopsies from CD patients vs. UC and independent of an ion transport response. These data indicate that lubiprostone has potential efficacy in improving mucosal integrity in Crohn’s disease.
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Pathophysiological role of ion channels and transporters in gastrointestinal mucosal diseases. Cell Mol Life Sci 2021; 78:8109-8125. [PMID: 34778915 PMCID: PMC8629801 DOI: 10.1007/s00018-021-04011-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 09/10/2021] [Accepted: 10/23/2021] [Indexed: 11/13/2022]
Abstract
The incidence of gastrointestinal (GI) mucosal diseases, including various types of gastritis, ulcers, inflammatory bowel disease and GI cancer, is increasing. Therefore, it is necessary to identify new therapeutic targets. Ion channels/transporters are located on cell membranes, and tight junctions (TJs) affect acid–base balance, the mucus layer, permeability, the microbiota and mucosal blood flow, which are essential for maintaining GI mucosal integrity. As ion channel/transporter dysfunction results in various GI mucosal diseases, this review focuses on understanding the contribution of ion channels/transporters to protecting the GI mucosal barrier and the relationship between GI mucosal disease and ion channels/transporters, including Cl−/HCO3− exchangers, Cl− channels, aquaporins, Na+/H+ exchangers, and K+ channels. Here, we provide novel prospects for the treatment of GI mucosal diseases.
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Nighot M, Ganapathy AS, Saha K, Suchanec E, Castillo EF, Gregory A, Shapiro S, Ma T, Nighot P. Matrix Metalloproteinase MMP-12 Promotes Macrophage Transmigration Across Intestinal Epithelial Tight Junctions and Increases Severity of Experimental Colitis. J Crohns Colitis 2021; 15:1751-1765. [PMID: 33836047 PMCID: PMC8495490 DOI: 10.1093/ecco-jcc/jjab064] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND AIMS Matrix metalloproteinases [MMPs] play an important role in extracellular matrix regulation during cell growth and wound healing. Increased expression of MMP-12 [human macrophage elastase] has been reported in inflammatory bowel disease [IBD] which is characterised by the loss of epithelial tight junction [TJ] barrier function and an excessive inflammatory response. The aim of this study was to investigate the role of MMP-12 in intestinal TJ barrier function and inflammation. METHODS Wild type [WT] and MMP-12-/- mice were subjected to experimental acute or chronic dextran sodium sulphate [DSS] colitis. The mouse colonic permeability was measured in vivo by recycling perfusion of the entire colon and ex vivo by Ussing chamber studies. RESULTS DSS administration increased colonic permeability through modulation of TJ proteins and also increased MMP-12 expression in the colonic mucosa of WT mice. The acute as well as chronic DSS-induced increase in colonic TJ permeability and the severity of DSS colitis was found to be markedly attenuated in MMP-12-/- mice. The resistance of MMP-12-/- mice to DSS colitis was characterised by reduced macrophage infiltration and transmigration, and reduced basement membrane laminin degradation. Further in vitro and in vivo studies show that macrophage transmigration across the epithelial layer is MMP-12 dependent and the epithelial TJ barrier is compromised during macrophage transmigration. Conclusions: Together, these data demonstrate that MMP-12 mediated degradation of basement membrane laminin, macrophage transmigration, and associated loss of intestinal TJ barrier are key pathogenic factors for intestinal inflammation.
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Affiliation(s)
- Meghali Nighot
- Department of Medicine, College of Medicine, Penn State University, Hershey, PA, USA
| | | | - Kushal Saha
- Department of Medicine, College of Medicine, Penn State University, Hershey, PA, USA
| | - Eric Suchanec
- Department of Medicine, College of Medicine, Penn State University, Hershey, PA, USA
| | - Eliseo F Castillo
- University of New Mexico School of Medicine, Albuquerque, New Mexico, USA
| | - Alyssa Gregory
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Steven Shapiro
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Thomas Ma
- Department of Medicine, College of Medicine, Penn State University, Hershey, PA, USA
| | - Prashant Nighot
- Department of Medicine, College of Medicine, Penn State University, Hershey, PA, USA
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Deng X, Shang L, Du M, Yuan L, Xiong L, Xie X. Mechanism underlying the significant role of the miR-4262/SIRT1 axis in children with inflammatory bowel disease. Exp Ther Med 2020; 20:2227-2235. [PMID: 32765699 PMCID: PMC7401569 DOI: 10.3892/etm.2020.8918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 05/15/2020] [Indexed: 11/06/2022] Open
Abstract
Inflammatory bowel disease (IBD) is a term used to describe chronic and recurrent gastrointestinal disease. In total, >2 million individuals worldwide have been diagnosed with IBD, including ulcerative colitis (UC), Crohn's disease (CD) and indeterminate colitis. There is accumulating evidence to indicate that microRNAs (miRNAs or miRs) are involved in the development and progression of IBD. miR-4262, an underlying promoter in tumor diseases, has been reported to regulate inflammatory responses. However, the potential mechanisms underlying the role of miR-4262 in IBD remain unknown. The present study attempted to explore the role and mechanisms of miR-4262 in IBD. Firstly, reverse transcription-quantitative PCR (RT-qPCR) was used to detect the expression of miR-4262 in 30 IBD colonic mucosa tissues, 30 normal tissues, 2% dextran sulfate sodium (DSS)-treated Caco-2 cells and normal cells. It was demonstrated that the expression levels of miR-4262 in IBD colonic mucosa tissues and 2% DSS-stimulated Caco-2 cells were markedly higher compared with those in the control groups. Target gene prediction databases and dual-luciferase reporter assays were then used, and sirtuin 1 (SIRT1) was identified as a target gene of miR-4262. Furthermore, the levels of SIRT1 in 2% DSS-stimulated Caco-2 cells and IBD colonic mucosa tissues were suppressed compared with the corresponding control groups. In addition, it was observed that miR-4262 negatively regulated SIRT1 expression in Caco-2 cells. Thereafter, Caco-2 cells were treated with inhibitor control, miR-4262 inhibitor, control-siRNA or SIRT1-siRNA for 48 h, followed by 2% DSS treatment for 4 days. The secretion of inflammatory factors was analyzed via ELISA and RT-qPCR. MTT assay, flow cytometry and western blot analysis were performed to assess cell viability, apoptosis and NF-κB signaling pathway-related protein levels, respectively. The results indicated that DSS enhanced the inflammatory response, suppressed cell viability and promoted cell apoptosis, and this was decreased following transfection with an miR-4262 inhibitor. In addition, 2% DSS upregulated p-p65 expression and enhanced the ratio of p-p65/p65, while the miR-4246 inhibitor exerted an opposite effect. All the effects of miR-4262 inhibitor on Caco-2 cells were eliminated following transfection with SIRT1-siRNA. It was thus concluded that miR-4262 may serve a role in the progression of IBD via targeting SIRT1, and miR-4262/SIRT1 may represent a potential target for the diagnosis and treatment of IBD.
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Affiliation(s)
- Xiaozhi Deng
- Department of Children's Gastroenterology, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, P.R. China
| | - Lihong Shang
- Department of Children's Gastroenterology, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, P.R. China
| | - Min Du
- Department of Children's Gastroenterology, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, P.R. China
| | - Lan Yuan
- Department of Children's Gastroenterology, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, P.R. China
| | - Lijing Xiong
- Department of Children's Gastroenterology, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, P.R. China
| | - Xiaoli Xie
- Department of Children's Gastroenterology, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, P.R. China
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Nighot P, Ma T. Endocytosis of Intestinal Tight Junction Proteins: In Time and Space. Inflamm Bowel Dis 2020; 27:283-290. [PMID: 32497180 PMCID: PMC7813749 DOI: 10.1093/ibd/izaa141] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Indexed: 12/12/2022]
Abstract
Eukaryotic cells take up macromolecules and particles from the surrounding milieu and also internalize membrane proteins via a precise process of endocytosis. The role of endocytosis in diverse physiological processes such as cell adhesion, cell signaling, tissue remodeling, and healing is well recognized. The epithelial tight junctions (TJs), present at the apical lateral membrane, play a key role in cell adhesion and regulation of paracellular pathway. These vital functions of the TJ are achieved through the dynamic regulation of the presence of pore and barrier-forming proteins within the TJ complex on the plasma membrane. In response to various intracellular and extracellular clues, the TJ complexes are actively regulated by intracellular trafficking. The intracellular trafficking consists of endocytosis and recycling cargos to the plasma membrane or targeting them to the lysosomes for degradation. Increased intestinal TJ permeability is a pathological factor in inflammatory bowel disease (IBD), and the TJ permeability could be increased due to the altered endocytosis or recycling of TJ proteins. This review discusses the current information on endocytosis of intestinal epithelial TJ proteins. The knowledge of the endocytic regulation of the epithelial TJ barrier will provide further understanding of pathogenesis and potential targets for IBD and a wide variety of human disease conditions.
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Affiliation(s)
- Prashant Nighot
- Department of Medicine, College of Medicine, Penn State University, Hershey, PA, USA,Address correspondence to: Prashant Nighot, Department of Medicine, College of Medicine, Pennsylvania State University, 500 University Drive, Room C5814B, Hershey, PA, 17033, USA. E-mail:
| | - Thomas Ma
- Department of Medicine, College of Medicine, Penn State University, Hershey, PA, USA
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Slifer ZM, Blikslager AT. The Integral Role of Tight Junction Proteins in the Repair of Injured Intestinal Epithelium. Int J Mol Sci 2020; 21:ijms21030972. [PMID: 32024112 PMCID: PMC7036844 DOI: 10.3390/ijms21030972] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/10/2019] [Accepted: 10/14/2019] [Indexed: 12/29/2022] Open
Abstract
The intestinal epithelial monolayer forms a transcellular and paracellular barrier that separates luminal contents from the interstitium. The paracellular barrier consists of a highly organized complex of intercellular junctions that is primarily regulated by apical tight junction proteins and tight junction-associated proteins. This homeostatic barrier can be lost through a multitude of injurious events that cause the disruption of the tight junction complex. Acute repair after injury leading to the reestablishment of the tight junction barrier is crucial for the return of both barrier function as well as other cellular functions, including water regulation and nutrient absorption. This review provides an overview of the tight junction complex components and how they link to other plasmalemmal proteins, such as ion channels and transporters, to induce tight junction closure during repair of acute injury. Understanding the components of interepithelial tight junctions and the mechanisms of tight junction regulation after injury is crucial for developing future therapeutic targets for patients experiencing dysregulated intestinal permeability.
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Zhao D, Wu N, Wang L, Pang X, Liu X, Zhang X. Role of microRNA-449a in the progress of inflammatory bowel disease in children. BIOTECHNOL BIOTEC EQ 2020. [DOI: 10.1080/13102818.2020.1724828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Affiliation(s)
- Dandan Zhao
- Pediatric Gastrointestinal Department, The First Hospital of Jilin University, Changchun, Jilin, PR China
| | - Na Wu
- Department of Neonatology, The First Hospital of Jilin University, Changchun, Jilin, PR China
| | - Libo Wang
- Pediatric Gastrointestinal Department, The First Hospital of Jilin University, Changchun, Jilin, PR China
| | - Xiaoli Pang
- Pediatric Gastrointestinal Department, The First Hospital of Jilin University, Changchun, Jilin, PR China
| | - Xuehua Liu
- Department of Pediatric Hematology, The First Hospital of Jilin University, Changchun, Jilin, PR China
| | - Xiaohong Zhang
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin, PR China
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Daulagala AC, Bridges MC, Kourtidis A. E-cadherin Beyond Structure: A Signaling Hub in Colon Homeostasis and Disease. Int J Mol Sci 2019; 20:E2756. [PMID: 31195621 PMCID: PMC6600153 DOI: 10.3390/ijms20112756] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 05/27/2019] [Accepted: 06/01/2019] [Indexed: 12/17/2022] Open
Abstract
E-cadherin is the core component of epithelial adherens junctions, essential for tissue development, differentiation, and maintenance. It is also fundamental for tissue barrier formation, a critical function of epithelial tissues. The colon or large intestine is lined by an epithelial monolayer that encompasses an E-cadherin-dependent barrier, critical for the homeostasis of the organ. Compromised barriers of the colonic epithelium lead to inflammation, fibrosis, and are commonly observed in colorectal cancer. In addition to its architectural role, E-cadherin is also considered a tumor suppressor in the colon, primarily a result of its opposing function to Wnt signaling, the predominant driver of colon tumorigenesis. Beyond these well-established traditional roles, several studies have portrayed an evolving role of E-cadherin as a signaling epicenter that regulates cell behavior in response to intra- and extra-cellular cues. Intriguingly, these recent findings also reveal tumor-promoting functions of E-cadherin in colon tumorigenesis and new interacting partners, opening future avenues of investigation. In this Review, we focus on these emerging aspects of E-cadherin signaling, and we discuss their implications in colon biology and disease.
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Affiliation(s)
- Amanda C Daulagala
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA.
| | - Mary Catherine Bridges
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA.
| | - Antonis Kourtidis
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA.
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12
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Wong M, Ganapathy AS, Suchanec E, Laidler L, Ma T, Nighot P. Intestinal epithelial tight junction barrier regulation by autophagy-related protein ATG6/beclin 1. Am J Physiol Cell Physiol 2019; 316:C753-C765. [PMID: 30892937 DOI: 10.1152/ajpcell.00246.2018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A defective tight junction (TJ) barrier is a key pathogenic factor for inflammatory bowel disease. Previously, we have shown that autophagy, a cell survival mechanism, enhances intestinal epithelial TJ barrier function. Autophagy-related protein-6 (ATG6/beclin 1), a key protein in the autophagy pathway, also plays a role in the endocytic pathway. The constitutive role of beclin 1 in the intestinal TJ barrier is not known. In Caco-2 cells, beclin 1 was found to be coimmunoprecipitated with the TJ protein occludin and colocalized with occludin on the membrane. Treatment of Caco-2 cells with beclin 1 peptide [transactivating regulatory protein (Tat)-beclin 1] reduced TJ barrier function. Activation of beclin 1 increased occludin endocytosis and reduced total occludin protein level. In contrast, beclin 1 siRNA transfection enhanced Caco-2 TJ barrier function. In pharmacologic and genetic autophagy inhibition studies, the constitutive function of beclin 1 in the TJ barrier was found to be autophagy independent. However, de novo induction of autophagy with starvation or rapamycin prevented Tat-beclin 1-induced increase in TJ permeability and reduction in occludin level. Induction of autophagy also resulted in reduced beclin 1-occludin association. In mouse colon, beclin 1 colocalized with occludin on the epithelial membrane. Perfusion of mouse colon with beclin 1 peptide caused an increase in colonic TJ permeability that was prevented by in vivo induction of autophagy. These findings show that beclin 1 plays a constitutive, autophagy-independent role in the regulation of intestinal TJ barrier function via endocytosis of occludin. Autophagy terminates constitutive beclin 1 function in the TJ barrier and enhances the TJ barrier.
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Affiliation(s)
- Morgan Wong
- Department of Internal Medicine, University of New Mexico School of Medicine , Albuquerque, New Mexico
| | | | - Eric Suchanec
- Department of Medicine, College of Medicine, Pennsylvania State University , Hershey, Pennsylvania
| | - Laura Laidler
- Department of Internal Medicine, University of New Mexico School of Medicine , Albuquerque, New Mexico
| | - Thomas Ma
- Department of Medicine, College of Medicine, Pennsylvania State University , Hershey, Pennsylvania
| | - Prashant Nighot
- Department of Medicine, College of Medicine, Pennsylvania State University , Hershey, Pennsylvania
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Jin Y, Ibrahim D, Magness ST, Blikslager AT. Knockout of ClC-2 reveals critical functions of adherens junctions in colonic homeostasis and tumorigenicity. Am J Physiol Gastrointest Liver Physiol 2018; 315:G966-G979. [PMID: 30285466 PMCID: PMC6336945 DOI: 10.1152/ajpgi.00087.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Adherens junctions (AJs), together with tight junctions (TJs), form an apical junctional complex that regulates intestinal epithelial cell-to-cell adherence and barrier homeostasis. Within the AJ, membrane-bound E-cadherin binds β-catenin, which functions as an essential intracellular signaling molecule. We have previously identified a novel protein in the region of the apical junction complex, chloride channel protein-2 (ClC-2), that we have used to study TJ regulation. In this study, we investigated the possible effects of ClC-2 on the regulation of AJs in intestinal mucosal epithelial homeostasis and tumorigenicity. Mucosal homeostasis and junctional proteins were examined in wild-type (WT) and ClC-2 knockout (KO) mice as well as associated colonoids. Tumorigenicity and AJ-associated signaling were evaluated in a murine colitis-associated tumor model and in a colorectal cancer cell line (HT-29). Colonic tissues from ClC-2 KO mice had altered ultrastructural morphology of intercellular junctions with reduced colonocyte differentiation, whereas jejunal tissues had minimal changes. Colonic crypts from ClC-2 KO mice had significantly higher numbers of less-differentiated forms of colonoids compared with WT. Furthermore, the absence of ClC-2 resulted in redistribution of AJ proteins and increased β-catenin activity. Downregulation of ClC-2 in colorectal cells resulted in significant increases in proliferation associated with disruption of AJs. Colitis-associated tumors in ClC-2 KO mice were significantly increased, associated with β-catenin transcription factor activation. The absence of ClC-2 results in less differentiated colonic crypts and increased tumorigenicity associated with colitis via dysregulation of AJ proteins and activation of β-catenin-associated signaling. NEW & NOTEWORTHY Disruption of adherens junctions in the absence of chloride channel protein-2 revealed critical functions of these junctional structures, including maintenance of colonic homeostasis and differentiation as well as driving tumorigenicity by regulating β-catenin signaling.
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Affiliation(s)
- Younggeon Jin
- 1Department of Clinical Sciences, Center for Gastrointestinal Biology and Disease, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Dina Ibrahim
- 1Department of Clinical Sciences, Center for Gastrointestinal Biology and Disease, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Scott T. Magness
- 1Department of Clinical Sciences, Center for Gastrointestinal Biology and Disease, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina,2Joint Department of Biomedical Engineering, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina
| | - Anthony T. Blikslager
- 1Department of Clinical Sciences, Center for Gastrointestinal Biology and Disease, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
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Zhao Q, Liu Y, Tan L, Yan L, Zuo X. Adiponectin administration alleviates DSS-induced colonic inflammation in Caco-2 cells and mice. Inflamm Res 2018; 67:663-670. [PMID: 29766204 PMCID: PMC6028846 DOI: 10.1007/s00011-018-1155-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 04/27/2018] [Accepted: 05/03/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Adiponectin, a protein hormone produced by adipose tissues, exhibits anti-inflammatory functions in various models. This study was investigated the effects of adiponectin on dextran sodium sulfate (DSS)-colonic injury, inflammation, apoptosis, and intestinal barrier dysfunction in Caco-2 cell and mice. MATERIALS AND METHODS The results showed that DSS caused inflammatory response and intestinal barrier dysfunction in vitro and in vivo. Adiponectin injection alleviated colonic injury and rectal bleeding in mice. Meanwhile, adiponectin downregulated colonic IL-1β and TNF-α expressions and regulated apoptosis relative genes to attenuate DSS-induced colonic inflammation and apoptosis. Adiponectin markedly reduced serum lipopolysaccharide concentration, a biomarker for intestinal integrity, and enhanced colonic expression of tight junctions (ZO-1 and occludin). The in vitro data further demonstrated that adiponectin alleviated DSS-induced proinflammatory cytokines production and the increased permeability in Caco-2 cells. CONCLUSION Adiponectin plays a beneficial role in DSS-induced inflammation via alleviating apoptosis and improving intestinal barrier integrity.
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Affiliation(s)
- Qin Zhao
- Department of Gastroenterology, Taian City Central Hospital, Taian, Shandong, People's Republic of China
| | - Yang Liu
- Department of Medicine, Beijing 316 Hospital, Beijing, People's Republic of China
| | - Lei Tan
- Department of Cerebral Surgery, Taian City Central Hospital, Taian, Shandong, People's Republic of China
| | - Liyong Yan
- Department of Stomatology, Taian City Central Hospital, Taian, Shandong, People's Republic of China
| | - Xiuli Zuo
- Department of Gastroenterology, Qilu Hospital, Shandong University, 107 Wenhua West Road, Jinan, 250012, People's Republic of China.
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15
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Matrine alleviates lipopolysaccharide-induced intestinal inflammation and oxidative stress via CCR7 signal. Oncotarget 2017; 8:11621-11628. [PMID: 28086227 PMCID: PMC5355291 DOI: 10.18632/oncotarget.14598] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 12/27/2016] [Indexed: 11/25/2022] Open
Abstract
The aim of this study was to investigate the protective effects of matrine on lipopolysaccharide (LPS)-induced inflammation and oxidative stress in vivo and in vitro. The results showed that matrine improved intestinal inflammatory status and oxidative balance and enhanced chemokine receptor 7 (CCR7) expression. In LPS-challenged mice and Caco-2 cells, matrine alleviated LPS-induced inflammation and oxidative stress via downregulating pro-inflammatory cytokines (IL-1β and IL-17) and malondialdehyde (MDA) production. CCR7-siRNA transfection blocked the protective effects of matrine on LPS-induced inflammation and oxidative stress and exacerbated LPS caused injury. In conclusion, matrine alleviates LPS-induced intestinal inflammation and oxidative stress in mice and Caco-2 cells, which may be associated with CCR7 signal.
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16
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Genistein improves inflammatory response and colonic function through NF-κB signal in DSS-induced colonic injury. Oncotarget 2017; 8:61385-61392. [PMID: 28977871 PMCID: PMC5617431 DOI: 10.18632/oncotarget.18219] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 04/05/2017] [Indexed: 12/21/2022] Open
Abstract
This study aimed to investigate the protective potential of genistein in dextran sulfate sodium (DSS)-induced colonic injury in vitro and in vivo models. The results showed that DSS exposure caused growth suppression, colonic injury, inflammation, and barrier dysfunction in mice. Dietary genistein alleviated DSS-caused colonic injury via reducing colonic weight, rectal bleeding, and diarrhea ratio. Meanwhile, genistein reduced colonic inflammatory response via downregulating cytokines expression and improved colonic permeability and barrier in DSS-challenged mice. In Caco-2 cells, genistein improved cell viability and cellular permeability and inhibited DSS-induced activation of TLR4/NF-κB signal. In conclusion, genistein alleviated DSS-caused colonic injury, inflammation, and gut dysfunction, which might be associated with the TLR4/NF-κB signal.
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17
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Nighot PK, Leung L, Ma TY. Chloride channel ClC- 2 enhances intestinal epithelial tight junction barrier function via regulation of caveolin-1 and caveolar trafficking of occludin. Exp Cell Res 2017; 352:113-122. [PMID: 28161538 DOI: 10.1016/j.yexcr.2017.01.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 01/09/2017] [Accepted: 01/31/2017] [Indexed: 12/16/2022]
Abstract
Previous studies have demonstrated that the chloride channel ClC-2 plays a critical role in intestinal epithelial tight junction (TJ) barrier function via intracellular trafficking of TJ protein occludin. To study the mechanism of ClC-2-mediated TJ barrier function and intracellular trafficking of occludin, we established ClC-2 over-expressing Caco-2 cell line (Caco-2CLCN2) by full length ClC-2 ORF transfection. ClC-2 over-expression (Caco-2CLCN2) significantly enhanced TJ barrier (increased TER by ≥2 times and reduced inulin flux by 50%) compared to control Caco-2pEZ cells. ClC-2 over-expression (Caco-2CLCN2) increased occludin protein level compared to control Caco-2pEZ cells. Surface biotinylation assay revealed reduced steady state endocytosis of occludin in Caco-2CLCN2 cells. Furthermore, ClC-2 over-expression led to reduction in caveolin-1 protein level and diminishment of caveolae assembly. Caveolae disruption increased TJ permeability in control but not ClC-2 over-expressing Caco-2CLCN2 cells. Selective ClC-2 channel blocker GaTx2 caused an increase in caveolin-1 protein level and reduced occludin level. Delivery of cell permeable caveolin-1 scaffolding domain reduced the occludin protein level. Over all, these results suggest that ClC- 2 enhances TJ barrier function in intestinal epithelial cells via regulation of caveolin-1 and caveolae-mediated trafficking of occludin.
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Affiliation(s)
- Prashant K Nighot
- Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA.
| | - Lana Leung
- Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA
| | - Thomas Y Ma
- Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA
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18
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Chen X, Liu XS. Hydrogen sulfide from a NaHS source attenuates dextran sulfate sodium (DSS)-induced inflammation via inhibiting nuclear factor-κB. J Zhejiang Univ Sci B 2016; 17:209-17. [PMID: 26984841 DOI: 10.1631/jzus.b1500248] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This study investigated the alleviating effects of hydrogen sulfide (H2S), derived from sodium hydrosulfide (NaHS), on inflammation induced by dextran sulfate sodium (DSS) in both in vivo and in vitro models. We found that NaHS injection markedly decreased rectal bleeding, diarrhea, and histological injury in DSS-challenged mice. NaHS (20 μmol/L) reversed DSS-induced inhibition in cell viability in Caco-2 cells and alleviated pro-inflammation cytokine expression in vivo and in vitro, indicating an anti-inflammatory function for H2S. It was also found that H2S may regulate cytokine expression by inhibiting the nuclear factor-κB (NF-κB) signaling pathway. In conclusion, our results demonstrated that H2S alleviated DSS-induced inflammation in vivo and in vitro and that the signal mechanism might be associated with the NF-κB signaling pathway.
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Affiliation(s)
- Xi Chen
- Medical College, Qingdao University, Qingdao 266021, China.,Department of Gastroenterology, Yantai Municipal Laiyang Central Hospital, Yantai 265200, China
| | - Xi-shuang Liu
- Medical College, Qingdao University, Qingdao 266021, China.,Department of Gastroenterology, the Affiliated Hospital of Qingdao University, Qingdao 266071, China
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19
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Yang Y, Zhang J, Chen X, Wu T, Xu X, Cao G, Li H, Li Y. UII/GPR14 is involved in NF-κB-mediated colonic inflammation in vivo and in vitro. Oncol Rep 2016; 36:2800-2806. [PMID: 27600191 DOI: 10.3892/or.2016.5069] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/04/2016] [Indexed: 12/12/2022] Open
Abstract
The present study was conducted to investigate the molecular mechanism of urotensin II (UII) and its receptor, G protein‑coupled receptor 14 (GPR14), in colonic inflammation. Urantide, a special antagonist of GPR14, and GPR14-siRNA were used to inhibit GPR14 signaling in dextran sulfate sodium (DSS)‑induced inflammation in mice and Caco-2 cells. The results showed that urantide alleviated rectal bleeding, histological injury and production of interleukin (IL)-17 and tumor necrosis factor‑α (TNF‑α) caused by DSS in mice. GPR14-siRNA transfection subsequent with GPR14 inhibition reduced DSS-induced interferon-γ (IFN)-γ production in Caco-2 cells. Meanwhile, both in vivo and in vitro data demonstrated that inhibition of UII/GPR14 alleviated nuclear factor-κB (NF-κB) activation caused by DSS. In conclusion, UII/GPR14 signaling was involved in the DSS-induced colonic inflammation and its inhibition may serve as a potential therapeutic target, which may be associated with the NF-κB signaling pathway.
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Affiliation(s)
- Yi Yang
- Department of General Surgery, Second Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Jinpei Zhang
- Department of Encephalopathy, Hospital of Shaanxi University of Chinese Medicine, Xianyang, Shaanxi 712000, P.R. China
| | - Xi Chen
- Department of General Surgery, Second Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Tao Wu
- Department of General Surgery, Second Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Xin Xu
- Department of General Surgery, Second Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Gang Cao
- Department of General Surgery, Second Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Hua Li
- Department of General Surgery, Second Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Yiming Li
- Department of General Surgery, Second Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
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20
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Abstract
Although the association between inflammatory bowel disease (IBD) and oral hygiene has been noticed before, there has been little research on prolonged fluoride exposure as a possible risk factor. In the presented cases, exposure to fluoride seems indirectly associated with higher incidence of IBD. Fluoride toxicology and epidemiology documents frequent unspecific chronic gastrointestinal symptoms and intestinal inflammation. Efflux genes that confer resistance to environmental fluoride may select for IBD associated gut microbiota and therefore be involved in the pathogenesis. Together these multidisciplinary results argue for further investigation on the hypothesis of fluoride as a risk factor for IBD.
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Affiliation(s)
| | - Bjørn Moum
- b Department of Gastroenterology , Oslo University Hospital Ullevaal & University of Oslo , Oslo , Norway
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21
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Zhao H, Yan R, Zhou X, Ji F, Zhang B. Hydrogen sulfide improves colonic barrier integrity in DSS-induced inflammation in Caco-2 cells and mice. Int Immunopharmacol 2016; 39:121-127. [PMID: 27472293 DOI: 10.1016/j.intimp.2016.07.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 06/29/2016] [Accepted: 07/18/2016] [Indexed: 02/07/2023]
Abstract
Intestinal barrier involves in the pathogeny of inflammatory bowel disease (IBD) and hydrogen sulfide (H2S) has been reported to improve intestinal barrier integrity. Thus, this study investigated the effects of GYY4137, a slow-release H2S donor, on DSS-induced inflammation and intestinal dysfunction. In vitro model, cellular permeability was significantly increased and expression of tight junctions (ZO-1, Cauldin4, and Occludin) was downregulated in Caco-2 cells. GYY4137 treatment markedly attenuated DSS-induced inflammation and barrier dysfunction. Cystathionine β-synthase (CBS)-siRNA transfection further demonstrated that endogenous H2S system involves in DSS-induced inflammation and mediates barrier function. In vivo model, DSS exposure caused colonic inflammation and injury in mice and GYY4137 injection alleviated inflammatory response and improved intestinal barrier via reducing intestinal permeability and upregulating of tight junctions. In conclusion, endogenous H2S system involves in DSS-induced inflammation and H2S addition alleviated inflammation and intestinal dysfunction in vitro and in vivo.
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Affiliation(s)
- Hongyu Zhao
- Department of Anesthesiology, Affiliated Tumor Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830011, China
| | - Rui Yan
- Department of Anesthesiology, Affiliated Tumor Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830011, China
| | - Xiaogang Zhou
- Department of General Surgery, People's Hospital of Changji Hui Autonomous Prefecture, Changji, Xinjiang 831100, China
| | - Fang Ji
- Department of Anesthesiology, Affiliated Tumor Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830011, China
| | - Bing Zhang
- Department of Anesthesiology, Affiliated Tumor Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830011, China.
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22
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RamaKrishnan AM, Sankaranarayanan K. Understanding autoimmunity: The ion channel perspective. Autoimmun Rev 2016; 15:585-620. [PMID: 26854401 DOI: 10.1016/j.autrev.2016.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Accepted: 01/29/2016] [Indexed: 12/11/2022]
Abstract
Ion channels are integral membrane proteins that orchestrate the passage of ions across the cell membrane and thus regulate various key physiological processes of the living system. The stringently regulated expression and function of these channels hold a pivotal role in the development and execution of various cellular functions. Malfunction of these channels results in debilitating diseases collectively termed channelopathies. In this review, we highlight the role of these proteins in the immune system with special emphasis on the development of autoimmunity. The role of ion channels in various autoimmune diseases is also listed out. This comprehensive review summarizes the ion channels that could be used as molecular targets in the development of new therapeutics against autoimmune disorders.
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Affiliation(s)
| | - Kavitha Sankaranarayanan
- AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chrompet, Chennai 600 044, India.
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23
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Nighot P, Al-Sadi R, Rawat M, Guo S, Watterson DM, Ma T. Matrix metalloproteinase 9-induced increase in intestinal epithelial tight junction permeability contributes to the severity of experimental DSS colitis. Am J Physiol Gastrointest Liver Physiol 2015; 309:G988-97. [PMID: 26514773 PMCID: PMC4683300 DOI: 10.1152/ajpgi.00256.2015] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/07/2015] [Indexed: 01/31/2023]
Abstract
Recent studies have implicated a pathogenic role for matrix metalloproteinases 9 (MMP-9) in inflammatory bowel disease. Although loss of epithelial barrier function has been shown to be a key pathogenic factor for the development of intestinal inflammation, the role of MMP-9 in intestinal barrier function remains unclear. The aim of this study was to investigate the role of MMP-9 in intestinal barrier function and intestinal inflammation. Wild-type (WT) and MMP-9(-/-) mice were subjected to experimental dextran sodium sulfate (DSS) colitis by administration of 3% DSS in drinking water for 7 days. The mouse colonic permeability was measured in vivo by recycling perfusion of the entire colon using fluorescently labeled dextran. The DSS-induced increase in the colonic permeability was accompanied by an increase in intestinal epithelial cell MMP-9 expression in WT mice. The DSS-induced increase in intestinal permeability and the severity of DSS colitis was found to be attenuated in MMP-9(-/-) mice. The colonic protein expression of myosin light chain kinase (MLCK) and phospho-MLC was found to be significantly increased after DSS administration in WT mice but not in MMP-9(-/-) mice. The DSS-induced increase in colonic permeability and colonic inflammation was attenuated in MLCK(-/-) mice and MLCK inhibitor ML-7-treated WT mice. The DSS-induced increase in colonic surface epithelial cell MLCK mRNA was abolished in MMP-9(-/-) mice. Lastly, increased MMP-9 protein expression was detected within the colonic surface epithelial cells in ulcerative colitis cases. These data suggest a role of MMP-9 in modulation of colonic epithelial permeability and inflammation via MLCK.
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Affiliation(s)
- Prashant Nighot
- 1Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, New Mexico;
| | - Rana Al-Sadi
- 1Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, New Mexico;
| | - Manmeet Rawat
- Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, New Mexico;
| | - Shuhong Guo
- 1Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, New Mexico;
| | - D. Martin Watterson
- 2Northwestern University Feinberg School of Medicine, Chicago, Illinois; and
| | - Thomas Ma
- 1Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, New Mexico; ,3Veterans Affairs Medical Center, Albuquerque, New Mexico
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Pharmaceutical Activation or Genetic Absence of ClC-2 Alters Tight Junctions During Experimental Colitis. Inflamm Bowel Dis 2015; 21:2747-57. [PMID: 26332307 DOI: 10.1097/mib.0000000000000550] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND We have previously reported that the ClC-2 chloride channel has an important role in regulation of tight junction barrier function during experimental colitis, and the pharmaceutical ClC-2 activator lubiprostone initiates intestinal barrier repair in ischemic-injured intestine. Thus, we hypothesized that pharmaceutical ClC-2 activation would have a protective and therapeutic effect in murine models of colitis, which would be absent in ClC-2 mice. METHODS We administered lubiprostone to wild-type or ClC-2 mice with dextran sulfate sodium (DSS) or 2, 4, 5-trinitrobenzene sulfonic acid-induced colitis. We determined the severity of colitis and assessed intestinal permeability. Selected tight junction proteins were analyzed by Western blotting and immunofluorescence/confocal microscopy, whereas proliferative and differentiated cells were examined with special staining and immunohistochemistry. RESULTS Oral preventive or therapeutic administration of lubiprostone significantly reduced the severity of colitis and reduced intestinal permeability in both DSS and trinitrobenzene sulfonic acid-induced colitis. Preventive treatment with lubiprostone induced significant recovery of the expression and distribution of selected sealing tight junction proteins in mice with DSS-induced colitis. In addition, lubiprostone reduced crypt proliferation and increased the number of differentiated epithelial cells. Alternatively, when lubiprostone was administered to ClC-2 mice, the protective effect against DSS colitis was limited. CONCLUSIONS This study suggests a central role for ClC-2 in restoration of barrier function and tight junction architecture in experimental murine colitis, which can be therapeutically targeted with lubiprostone.
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25
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Jin Y, Blikslager AT. ClC-2 regulation of intestinal barrier function: Translation of basic science to therapeutic target. Tissue Barriers 2015; 3:e1105906. [PMID: 26716076 DOI: 10.1080/21688370.2015.1105906] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 09/28/2015] [Accepted: 10/01/2015] [Indexed: 02/06/2023] Open
Abstract
The ClC-2 chloride channel is a member of the voltage-gated chloride channel family. ClC-2 is involved in various physiological processes, including fluid transport and secretion, regulation of cell volume and pH, maintaining the membrane potential of the cell, cell-to-cell communication, and tissue homeostasis. Recently, our laboratory has accumulated evidence indicating a critical role of ClC-2 in the regulation of intestinal barrier function by altering inter-epithelial tight junction composition. This review will detail the role of ClC-2 in intestinal barrier function during intestinal disorders, including experimental ischemia/reperfusion injury and dextran sodium sulfate (DSS)-induced inflammatory bowel disease. Details of pharmacological manipulation of ClC-2 via prostone agonists will also be provided in an effort to show the potential therapeutic relevance of ClC-2 regulation, particularly during intestinal barrier disruption.
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Affiliation(s)
- Younggeon Jin
- Department of Clinical Sciences; College of Veterinary Medicine, North Carolina State University ; Raleigh, NC, USA
| | - Anthony T Blikslager
- Department of Clinical Sciences; College of Veterinary Medicine, North Carolina State University ; Raleigh, NC, USA
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26
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Yu H, Dong M, Xu Y, He N, Dai X, Li K. Arginyl-glutamine dipeptide attenuates experimental colitis by enhancing antioxidant function and inhibiting nuclear factor-kappaB. RSC Adv 2015. [DOI: 10.1039/c5ra16739f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
This study aimed to investigate the effect and underlying mechanism of Arginyl-glutamine (AG) dipeptide on dextran sulfate sodium (DSS)-induced colitis byin vivoandin vitromodels.
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Affiliation(s)
- Hua Yu
- Department of Analogy
- Ningbo No. 2 Hospital
- Ningbo 315010
- China
| | - Mingjun Dong
- Department of Analogy
- Ningbo No. 2 Hospital
- Ningbo 315010
- China
| | - Yidong Xu
- Department of Analogy
- Ningbo No. 2 Hospital
- Ningbo 315010
- China
| | - Ning He
- Department of Analogy
- Ningbo No. 2 Hospital
- Ningbo 315010
- China
| | - Xiaoyu Dai
- Department of Analogy
- Ningbo No. 2 Hospital
- Ningbo 315010
- China
| | - Keqiang Li
- Department of Analogy
- Ningbo No. 2 Hospital
- Ningbo 315010
- China
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