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Vollstädt ML, Stein L, Brunner N, Amasheh S. Cinnamic Acid and Caffeic Acid Effects on Gastric Tight Junction Proteins Analyzed in Xenopus laevis Oocytes. MEMBRANES 2024; 14:40. [PMID: 38392667 PMCID: PMC10890460 DOI: 10.3390/membranes14020040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/21/2024] [Accepted: 01/29/2024] [Indexed: 02/24/2024]
Abstract
Analysis of secondary plant compounds for the development of novel therapies is a common focus of experimental biomedicine. Currently, multiple health-supporting properties of plant-derived molecules are known but still information on many mechanisms is scarce. Cinnamic acid and caffeic acid are two of the most abundant polyphenols in human dietary fruits and vegetables. In this study, we investigated cinnamic acid and caffeic acid effects on the gastric barrier, which is primarily provided by members of the transmembrane tight junction protein family of claudins. The Xenopus laevis oocyte has been established, in recent years, as a heterologous expression system for analysis of transmembrane tight junction protein interactions, by performing paired oocyte experiments to identify an effect on protein-protein interactions, in vitro. In our current study, human gastric claudin-4, -5, and -18.2. were expressed and detected in the oocyte plasma membrane by freeze fracture electron microscopy and immunoblotting. Oocytes were paired and incubated with 100 µM or 200 µM cinnamic acid or caffeic acid, or Ringer's solution, respectively. Caffeic acid showed no effect on the contact area strength of paired oocytes but led to an increased contact area size. In contrast, cinnamic acid-incubated paired oocytes revealed a reduced contact area and a strengthening effect on the contact area was identified. These results may indicate that caffeic acid and cinnamic acid both show an effect on gastric barrier integrity via direct effects on tight junction proteins.
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Affiliation(s)
- Marie-Luise Vollstädt
- School of Veterinary Medicine, Institute of Veterinary Physiology, Freie Universität Berlin, 14163 Berlin, Germany
| | - Laura Stein
- School of Veterinary Medicine, Institute of Veterinary Physiology, Freie Universität Berlin, 14163 Berlin, Germany
| | - Nora Brunner
- School of Veterinary Medicine, Institute of Veterinary Physiology, Freie Universität Berlin, 14163 Berlin, Germany
| | - Salah Amasheh
- School of Veterinary Medicine, Institute of Veterinary Physiology, Freie Universität Berlin, 14163 Berlin, Germany
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2
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Ramirez-Velez I, Belardi B. Storming the gate: New approaches for targeting the dynamic tight junction for improved drug delivery. Adv Drug Deliv Rev 2023; 199:114905. [PMID: 37271282 PMCID: PMC10999255 DOI: 10.1016/j.addr.2023.114905] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/20/2023] [Accepted: 05/29/2023] [Indexed: 06/06/2023]
Abstract
As biologics used in the clinic outpace the number of new small molecule drugs, an important challenge for their efficacy and widespread use has emerged, namely tissue penetrance. Macromolecular drugs - bulky, high-molecular weight, hydrophilic agents - exhibit low permeability across biological barriers. Epithelial and endothelial layers, for example within the gastrointestinal tract or at the blood-brain barrier, present the most significant obstacle to drug transport. Within epithelium, two subcellular structures are responsible for limiting absorption: cell membranes and intercellular tight junctions. Previously considered impenetrable to macromolecular drugs, tight junctions control paracellular flux and dictate drug transport between cells. Recent work, however, has shown tight junctions to be dynamic, anisotropic structures that can be targeted for delivery. This review aims to summarize new approaches for targeting tight junctions, both directly and indirectly, and to highlight how manipulation of tight junction interactions may help usher in a new era of precision drug delivery.
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Affiliation(s)
- Isabela Ramirez-Velez
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712, United States
| | - Brian Belardi
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712, United States.
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3
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Kim JE, Song HJ, Choi YJ, Jin YJ, Roh YJ, Seol A, Park SH, Park JM, Kang HG, Hwang DY. Improvement of the intestinal epithelial barrier during laxative effects of phlorotannin in loperamide-induced constipation of SD rats. Lab Anim Res 2023; 39:1. [PMID: 36597137 PMCID: PMC9808941 DOI: 10.1186/s42826-022-00152-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 12/12/2022] [Accepted: 12/16/2022] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Disruptions of the intestinal epithelial barrier (IEB) are frequently observed in various digestive diseases, including irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). This study assessed the improvement in the IEB during the laxative activity of phlorotannin (Pt) harvested from Ecklonia cava in constipation by examining the changes in the expression of the regulatory proteins for the tight junction (TJ) and adherens junction (AJ), and inflammatory cytokines in Sprague Dawley (SD) rats with loperamide (Lm)-induced constipation after a Pt treatment. RESULTS The Pt treatment induced laxative activity, including the improvement of feces-related parameters, gastrointestinal transit rate, and histological structure of the mid colon in Lm-treated SD rats. In addition, significant recovery effects were detected in the histology of IEB, including the mucus layer, epithelial cells, and lamina propria in the mid colon of Lm + Pt treated SD rats. The expression levels of E-cadherin and p120-catenin for AJ and the ZO-1, occludin, and Claudin-1 genes for TJ in epithelial cells were improved remarkably after the Pt treatment, but the rate of increase was different. Furthermore, the Pt treatment increased the expression level of several inflammatory cytokines, such as TNF-α, IL-6, IL-1β, IL-13, and IL-4 in Lm + Pt treated SD rats. CONCLUSIONS These results provide the first evidence that the laxative activity of Pt in SD rats with Lm-induced constipation phenotypes involve improvements in the IEB.
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Affiliation(s)
- Ji Eun Kim
- grid.262229.f0000 0001 0719 8572Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science/Life and Industry Convergence Research Institute/Laboratory Animal Resources Center, Pusan National University, Miryang, 50463 Korea
| | - Hee Jin Song
- grid.262229.f0000 0001 0719 8572Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science/Life and Industry Convergence Research Institute/Laboratory Animal Resources Center, Pusan National University, Miryang, 50463 Korea
| | - Yun Ju Choi
- grid.262229.f0000 0001 0719 8572Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science/Life and Industry Convergence Research Institute/Laboratory Animal Resources Center, Pusan National University, Miryang, 50463 Korea
| | - You Jeong Jin
- grid.262229.f0000 0001 0719 8572Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science/Life and Industry Convergence Research Institute/Laboratory Animal Resources Center, Pusan National University, Miryang, 50463 Korea
| | - Yu Jeong Roh
- grid.262229.f0000 0001 0719 8572Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science/Life and Industry Convergence Research Institute/Laboratory Animal Resources Center, Pusan National University, Miryang, 50463 Korea
| | - Ayun Seol
- grid.262229.f0000 0001 0719 8572Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science/Life and Industry Convergence Research Institute/Laboratory Animal Resources Center, Pusan National University, Miryang, 50463 Korea
| | - So Hae Park
- grid.262229.f0000 0001 0719 8572Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science/Life and Industry Convergence Research Institute/Laboratory Animal Resources Center, Pusan National University, Miryang, 50463 Korea
| | - Ju Min Park
- grid.262229.f0000 0001 0719 8572Department of Food Science and Nutrition, College of Human Ecology, Pusan National University, Busan, 46241 Korea
| | - Hyun Gu Kang
- grid.254229.a0000 0000 9611 0917Veterinary Medical Center, Department of Veterinary Theriogenology, College of Veterinary Medicine, Chungbuk National University, Cheongju, 28644 Korea
| | - Dae Youn Hwang
- grid.262229.f0000 0001 0719 8572Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science/Life and Industry Convergence Research Institute/Laboratory Animal Resources Center, Pusan National University, Miryang, 50463 Korea
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4
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Stein L, Brunner N, Amasheh S. Functional Analysis of Gastric Tight Junction Proteins in Xenopus laevis Oocytes. MEMBRANES 2022; 12:membranes12080731. [PMID: 35893449 PMCID: PMC9330571 DOI: 10.3390/membranes12080731] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/18/2022] [Accepted: 07/21/2022] [Indexed: 11/16/2022]
Abstract
The epithelial barrier is crucial for proper gastrointestinal function, preventing the unwanted passage of solutes and therefore representing a prerequisite for vectorial transport. Claudin-4 and claudin-18.2, two critical tight junction proteins of the gastric epithelium, seal neighboring cells in a physically and mechanically challenging environment. As the Xenopus laevis oocyte allows the functional and molecular analyses of claudin interaction, we have addressed the hypothesis that this interaction is not only dependent on mechanical force but also on pH. We expressed human claudin-4 and claudin-18 in Xenopus oocytes, and analyzed them in a two-cell model approach. Cells were clustered in pairs to form contact areas expressing CLDN18 + CLDN18, CLDN4/18 + CLDN4/18, and compared to controls, respectively. Contact areas in cells incubated in medium at pH 5.5 and 7.4 were quantified by employing transmitted light microscopy. After 24 h at pH 5.5, clustering of CLDN18 + CLDN18 and CLDN4/18 + CLDN4/18-expressing oocytes revealed a contact area reduced by 45% and 32%, compared with controls, respectively. A further approach, high-pressure impulse assay, revealed a stronger tight junction interaction at pH 5.5 in oocyte pairs expressing CLDN18 + CLDN18 or CLDN4/18 + CLDN4/18 indicating a protective role of claudin-18 for tight junction integrity during pH challenge. Thus, our current analysis of gastric tight junction proteins further establishes oocytes as an expression and two-cell screening model for tight junction integrity analysis of organ- and tissue-specific claudins by the characterization of homo- and heterophilic trans-interaction dependent on barrier effectors.
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Affiliation(s)
| | | | - Salah Amasheh
- Correspondence: ; Tel.: +49-30-838-62602; Fax: +49-30-838-462602
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Shashikanth N, France MM, Xiao R, Haest X, Rizzo HE, Yeste J, Reiner J, Turner JR. Tight junction channel regulation by interclaudin interference. Nat Commun 2022; 13:3780. [PMID: 35773259 PMCID: PMC9246906 DOI: 10.1038/s41467-022-31587-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 06/23/2022] [Indexed: 02/06/2023] Open
Abstract
Tight junctions form selectively permeable seals across the paracellular space. Both barrier function and selective permeability have been attributed to members of the claudin protein family, which can be categorized as pore-forming or barrier-forming. Here, we show that claudin-4, a prototypic barrier-forming claudin, reduces paracellular permeability by a previously unrecognized mechanism. Claudin-4 knockout or overexpression has minimal effects on tight junction permeability in the absence of pore-forming claudins. However, claudin-4 selectively inhibits flux across cation channels formed by claudins 2 or 15. Claudin-4-induced loss of claudin channel function is accompanied by reduced anchoring and subsequent endocytosis of pore-forming claudins. Analyses in nonepithelial cells show that claudin-4, which is incapable of independent polymerization, disrupts polymeric strands and higher order meshworks formed by claudins 2, 7, 15, and 19. This process of interclaudin interference, in which one claudin disrupts higher order structures and channels formed by a different claudin, represents a previously unrecognized mechanism of barrier regulation.
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Affiliation(s)
- Nitesh Shashikanth
- Laboratory of Mucosal Barrier Pathobiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Marion M France
- Laboratory of Mucosal Barrier Pathobiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Ruyue Xiao
- Laboratory of Mucosal Barrier Pathobiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Xenia Haest
- Laboratory of Mucosal Barrier Pathobiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Heather E Rizzo
- Laboratory of Mucosal Barrier Pathobiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Jose Yeste
- Laboratory of Mucosal Barrier Pathobiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Instituto de Microelectrónica de Barcelona, IMB-CNM (CSIC), Bellaterra, Spain
| | - Johannes Reiner
- Division of Gastroenterology and Endocrinology, Department of Medicine II, Rostock University Medical Center, Ernst-Heydemann-Str. 6, Rostock, Germany
| | - Jerrold R Turner
- Laboratory of Mucosal Barrier Pathobiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
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6
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Disruption of Claudin-Made Tight Junction Barriers by Clostridium perfringens Enterotoxin: Insights from Structural Biology. Cells 2022; 11:cells11050903. [PMID: 35269525 PMCID: PMC8909277 DOI: 10.3390/cells11050903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 02/26/2022] [Accepted: 03/02/2022] [Indexed: 02/01/2023] Open
Abstract
Claudins are a family of integral membrane proteins that enable epithelial cell/cell interactions by localizing to and driving the formation of tight junctions. Via claudin self-assembly within the membranes of adjoining cells, their extracellular domains interact, forming barriers to the paracellular transport of small molecules and ions. The bacterium Clostridium perfringens causes prevalent gastrointestinal disorders in mammals by employing an enterotoxin (CpE) that targets claudins. CpE binds to claudins at or near tight junctions in the gut and disrupts their barrier function, potentially by disabling their assembly or via cell signaling means—the mechanism(s) remain unclear. CpE ultimately destroys claudin-expressing cells through the formation of a cytotoxic membrane-penetrating β-barrel pore. Structures obtained by X-ray crystallography of CpE, claudins, and claudins in complex with CpE fragments have provided the structural bases of claudin and CpE functions, revealing potential mechanisms for the CpE-mediated disruption of claudin-made tight junctions. This review highlights current progress in this space—what has been discovered and what remains unknown—toward efforts to elucidate the molecular mechanism of CpE disruption of tight junction barriers. It further underscores the key insights obtained through structure that are being applied to develop CpE-based therapeutics that combat claudin-overexpressing cancers or modulate tight junction barriers.
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7
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PGC-1α mediates a metabolic host defense response in human airway epithelium during rhinovirus infections. Nat Commun 2021; 12:3669. [PMID: 34135327 PMCID: PMC8209127 DOI: 10.1038/s41467-021-23925-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 05/21/2021] [Indexed: 02/06/2023] Open
Abstract
Human rhinoviruses (HRV) are common cold viruses associated with exacerbations of lower airways diseases. Although viral induced epithelial damage mediates inflammation, the molecular mechanisms responsible for airway epithelial damage and dysfunction remain undefined. Using experimental HRV infection studies in highly differentiated human bronchial epithelial cells grown at air-liquid interface (ALI), we examine the links between viral host defense, cellular metabolism, and epithelial barrier function. We observe that early HRV-C15 infection induces a transitory barrier-protective metabolic state characterized by glycolysis that ultimately becomes exhausted as the infection progresses and leads to cellular damage. Pharmacological promotion of glycolysis induces ROS-dependent upregulation of the mitochondrial metabolic regulator, peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), thereby restoring epithelial barrier function, improving viral defense, and attenuating disease pathology. Therefore, PGC-1α regulates a metabolic pathway essential to host defense that can be therapeutically targeted to rescue airway epithelial barrier dysfunction and potentially prevent severe respiratory complications or secondary bacterial infections. Epithelial host defense to rhinovirus infections is enhanced by targeting the mitochondrial metabolic regulator, PGC-1a. Using metabolomics and proteomics, Michi et al show that human airway epithelial cells mount a barrier-protective early glycolysis-shift in response to rhinovirus, and that by targeting PGC-1a early in infection, epithelial barrier function, viral defense and pathology are improved.
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8
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Abstract
The apical junctional complexes (AJCs) of airway epithelial cells are a key component of the innate immune system by creating barriers to pathogens, inhaled allergens, and environmental particles. AJCs form between adjacent cells and consist of tight junctions (TJs) and adherens junctions (AJs). Respiratory viruses have been shown to target various components of the AJCs, leading to airway epithelial barrier dysfunction by different mechanisms. Virus-induced epithelial permeability may allow for allergens and bacterial pathogens to subsequently invade. In this review, we discuss the pathophysiologic mechanisms leading to disruption of AJCs and the potential ensuing ramifications. We focus on the following viruses that affect the pulmonary system: respiratory syncytial virus, rhinovirus, influenza viruses, immunodeficiency virus, and other viruses such as coxsackievirus, adenovirus, coronaviruses, measles, parainfluenza virus, bocavirus, and vaccinia virus. Understanding the mechanisms by which viruses target the AJC and impair barrier function may help design therapeutic innovations to treat these infections.
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Affiliation(s)
- Debra T Linfield
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - Andjela Raduka
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, Ohio, USA
| | - Mahyar Aghapour
- Institute of Medical Microbiology, Otto-von-Guericke University, Magdeburg, Germany
| | - Fariba Rezaee
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, Ohio, USA.,Center for Pediatric Pulmonary Medicine, Cleveland, Ohio, USA
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9
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Rudraraju M, Narayanan SP, Somanath PR. Regulation of blood-retinal barrier cell-junctions in diabetic retinopathy. Pharmacol Res 2020; 161:105115. [PMID: 32750417 PMCID: PMC7755666 DOI: 10.1016/j.phrs.2020.105115] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/22/2020] [Accepted: 07/27/2020] [Indexed: 12/15/2022]
Abstract
Loss of the blood-retinal barrier (BRB) integrity and subsequent damage to the neurovascular unit in the retina are the underlying reasons for diabetic retinopathy (DR). Damage to BRB eventually leads to severe visual impairment in the absence of prompt intervention. Diabetic macular edema and proliferative DR are the advanced stages of the disease where BRB integrity is altered. Primary mechanisms contributing to BRB dysfunction include loss of cell-cell barrier junctions, vascular endothelial growth factor, advanced glycation end products-induced damage, and oxidative stress. Although much is known about the involvement of adherens and tight-junction proteins in the regulation of vascular permeability in various diseases, there is a significant gap in our knowledge on the junctional proteins expressed in the BRB and how BRB function is modulated in the diabetic retina. In this review article, we present our current understanding of the molecular composition of BRB, the changes in the BRB junctional protein turnover in DR, and how BRB functional modulation affects vascular permeability and macular edema in the diabetic retina.
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Affiliation(s)
- Madhuri Rudraraju
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, GA 30912, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA 30912, United States
| | - S Priya Narayanan
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, GA 30912, United States; Vascular Biology Center, Augusta University, Augusta, GA 30912, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA 30912, United States
| | - Payaningal R Somanath
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, GA 30912, United States; Vascular Biology Center, Augusta University, Augusta, GA 30912, United States; Department of Medicine, Augusta University, Augusta, GA 30912, United States.
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10
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A Weak Link with Actin Organizes Tight Junctions to Control Epithelial Permeability. Dev Cell 2020; 54:792-804.e7. [PMID: 32841596 DOI: 10.1016/j.devcel.2020.07.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 05/23/2020] [Accepted: 07/29/2020] [Indexed: 01/13/2023]
Abstract
In vertebrates, epithelial permeability is regulated by the tight junction (TJ) formed by specialized adhesive membrane proteins, adaptor proteins, and the actin cytoskeleton. Despite the TJ's critical physiological role, a molecular-level understanding of how TJ assembly sets the permeability of epithelial tissue is lacking. Here, we identify a 28-amino-acid sequence in the TJ adaptor protein ZO-1, which is responsible for actin binding, and show that this interaction is essential for TJ permeability. In contrast to the strong interactions at the adherens junction, we find that the affinity between ZO-1 and actin is surprisingly weak, and we propose a model based on kinetic trapping to explain how affinity could affect TJ assembly. Finally, by tuning the affinity of ZO-1 to actin, we demonstrate that epithelial monolayers can be engineered with a spectrum of permeabilities, which points to a promising target for treating transport disorders and improving drug delivery.
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11
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Pérez AG, Andrade-Da-Costa J, De Souza WF, De Souza Ferreira M, Boroni M, De Oliveira IM, Freire-Neto CA, Fernandes PV, De Lanna CA, Souza-Santos PT, Morgado-Díaz JA, De-Freitas-Junior JCM. N‑glycosylation and receptor tyrosine kinase signaling affect claudin‑3 levels in colorectal cancer cells. Oncol Rep 2020; 44:1649-1661. [PMID: 32945502 PMCID: PMC7448416 DOI: 10.3892/or.2020.7727] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 07/14/2020] [Indexed: 12/14/2022] Open
Abstract
Changes in protein levels in different components of the apical junctional complex occur in colorectal cancer (CRC). Claudin-3 is one of the main constituents of tight junctions, and its overexpression can increase the paracellular flux of macromolecules, as well as the malignant potential of CRC cells. The aim of this study was to investigate the molecular mechanisms involved in the regulation of claudin-3 and its prognostic value in CRC. In silico evaluation in each of the CRC consensus molecular subtypes (CMSs) revealed that high expression levels of CLDN3 (gene encoding claudin-3) in CMS2 and CMS3 worsened the patients' long-term survival, whereas a decrease in claudin-3 levels concomitant with a reduction in phosphorylation levels of epidermal growth factor receptor (EGFR) and insulin-like growth factor 1 receptor (IGF1R) could be achieved by inhibiting N-glycan biosynthesis in CRC cells. We also observed that specific inactivation of these receptor tyrosine kinases (RTKs) led to a decrease in claudin-3 levels, and this regulation seems to be mediated by phospholipase C (PLC) and signal transducer and activator of transcription 3 (STAT3) in CRC cells. RTKs are modulated by their N-linked glycans, and inhibition of N-glycan biosynthesis decreased the claudin-3 levels; therefore, we evaluated the correlation between N-glycogenes and CLDN3 expression levels in each of the CRC molecular subtypes. The CMS1 (MSI immune) subtype concomitantly exhibited low expression levels of CLDN3 and N-glycogenes (MGAT5, ST6GAL1, and B3GNT8), whereas CMS2 (canonical) exhibited high gene expression levels of CLDN3 and N-glycogenes (ST6GAL1 and B3GNT8). A robust positive correlation was also observed between CLDN3 and B3GNT8 expression levels in all CMSs. These results support the hypothesis of a mechanism integrating RTK signaling and N-glycosylation for the regulation of claudin-3 levels in CRC, and they suggest that CLDN3 expression can be used to predict the prognosis of patients identified as CMS2 or CMS3.
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Affiliation(s)
- Amelia G Pérez
- Cellular and Molecular Oncobiology Program, National Cancer Institute (INCA), Rio de Janeiro, RJ 20231‑050, Brazil
| | - Jéssica Andrade-Da-Costa
- Cellular and Molecular Oncobiology Program, National Cancer Institute (INCA), Rio de Janeiro, RJ 20231‑050, Brazil
| | - Waldemir F De Souza
- Cellular and Molecular Oncobiology Program, National Cancer Institute (INCA), Rio de Janeiro, RJ 20231‑050, Brazil
| | - Michelle De Souza Ferreira
- Cellular and Molecular Oncobiology Program, National Cancer Institute (INCA), Rio de Janeiro, RJ 20231‑050, Brazil
| | - Mariana Boroni
- Bioinformatics and Computational Biology Laboratory, National Cancer Institute (INCA), Rio de Janeiro, RJ 20231‑050, Brazil
| | - Ivanir M De Oliveira
- Pathology Division, National Cancer Institute (INCA), Rio de Janeiro, RJ 20231‑050, Brazil
| | - Carlos A Freire-Neto
- Cellular and Molecular Oncobiology Program, National Cancer Institute (INCA), Rio de Janeiro, RJ 20231‑050, Brazil
| | - Priscila V Fernandes
- Pathology Division, National Cancer Institute (INCA), Rio de Janeiro, RJ 20231‑050, Brazil
| | - Cristóvão A De Lanna
- Bioinformatics and Computational Biology Laboratory, National Cancer Institute (INCA), Rio de Janeiro, RJ 20231‑050, Brazil
| | | | - José A Morgado-Díaz
- Cellular and Molecular Oncobiology Program, National Cancer Institute (INCA), Rio de Janeiro, RJ 20231‑050, Brazil
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12
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Lynn KS, Peterson RJ, Koval M. Ruffles and spikes: Control of tight junction morphology and permeability by claudins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183339. [PMID: 32389670 DOI: 10.1016/j.bbamem.2020.183339] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/24/2020] [Accepted: 05/01/2020] [Indexed: 02/06/2023]
Abstract
Epithelial barrier function is regulated by a family of transmembrane proteins known as claudins. Functional tight junctions are formed when claudins interact with other transmembrane proteins, cytosolic scaffold proteins and the actin cytoskeleton. The predominant scaffold protein, zonula occludens-1 (ZO-1), directly binds to most claudin C-terminal domains, crosslinking them to the actin cytoskeleton. When imaged by immunofluorescence microscopy, tight junctions most frequently are linear structures that form between tricellular junctions. However, tight junctions also adapt non-linear architectures exhibiting either a ruffled or spiked morphology, which both are responses to changes in claudin engagement of actin filaments. Other terms for ruffled tight junctions include wavy, tortuous, undulating, serpentine or zig-zag junctions. Ruffling is under the control of hypoxia induced factor (HIF) and integrin-mediated signaling, as well as direct mechanical stimulation. Tight junction ruffling is specifically enhanced by claudin-2, antagonized by claudin-1 and requires claudin binding to ZO-1. Tight junction spikes are sites of active vesicle budding and fusion that appear as perpendicular projections oriented towards the nucleus. Spikes share molecular features with focal adherens junctions and tubulobulbar complexes found in Sertoli cells. Lung epithelial cells under stress form spikes due to an increase in claudin-5 expression that directly disrupts claudin-18/ZO-1 interactions. Together this suggests that claudins are not simply passive cargoes controlled by scaffold proteins. We propose a model where claudins specifically influence tight junction scaffold proteins to control interactions with the cytoskeleton as a mechanism that regulates tight junction assembly and function.
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Affiliation(s)
- K Sabrina Lynn
- Division of Pulmonary, Allergy Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Raven J Peterson
- Division of Pulmonary, Allergy Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Michael Koval
- Division of Pulmonary, Allergy Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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13
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Wu CJ, Lu M, Feng X, Nakato G, Udey MC. Matriptase Cleaves EpCAM and TROP2 in Keratinocytes, Destabilizing Both Proteins and Associated Claudins. Cells 2020; 9:cells9041027. [PMID: 32326212 PMCID: PMC7226414 DOI: 10.3390/cells9041027] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/17/2020] [Accepted: 04/19/2020] [Indexed: 02/07/2023] Open
Abstract
The homologs EpCAM and TROP2, which both interact with claudin-1 and claudin-7, are frequently coexpressed in epithelia including skin. Intestine uniquely expresses high levels of EpCAM but not TROP2. We previously identified EpCAM as a substrate of the membrane-anchored protease matriptase and linked HAI-2, matriptase, EpCAM and claudin-7 in a pathway that is pivotal for intestinal epithelial cells (IEC) homeostasis. Herein, we reveal that TROP2 is also a matriptase substrate. Matriptase cleaved TROP2 when purified recombinant proteins were mixed in vitro. TROP2, like EpCAM, was also cleaved after co-transfection of matriptase in 293T cells. Neither EpCAM nor TROP2 cleavage was promoted by protease-disabled matriptase or matriptase that harbored the ichthyosis-associated G827R mutation. We confirmed that EpCAM and TROP2 are both expressed in skin and detected cleavage of these proteins in human keratinocytes (HaCaT cells) after the physiologic inhibition of matriptase by HAI proteins was relieved by siRNA knockdown. Knockdown of EpCAM or TROP2 individually had only small effects on claudin-1 and claudin-7 levels, whereas elimination of both markedly diminished claudin levels. HAI-1 knockdown promoted EpCAM and TROP2 cleavage accompanied by reductions in claudins, whereas HAI-2 knockdown had little impact. Double knockdown of HAI-1 and HAI-2 induced nearly complete cleavage of EpCAM and TROP2 and drastic reductions of claudins. These effects were eliminated by concurrent matriptase knockdown. Decreases in claudin levels were also diminished by the lysosomal inhibitor chloroquine and cleaved EpCAM/TROP2 fragments accumulated preferentially. We demonstrate that TROP2 and EpCAM exhibit redundancies with regard to regulation of claudin metabolism and that an HAI, matriptase, EpCAM and claudin pathway analogous to what we described in IECs exists in keratinocytes. This study may offer insights into the mechanistic basis for matriptase dysregulation-induced ichthyosis.
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Affiliation(s)
- Chuan-Jin Wu
- Laboratory of Immune Cell Biology, National Cancer Institute, Bethesda, MD 20892, USA
- Correspondence: (C.-J.W.); (M.C.U.); Tel.: +1-301-760-7452 (C.-J.W.); +1-314-454-8547 (M.C.U.)
| | - Michael Lu
- Experimental Immunology Branch, National Cancer Institute, Bethesda, MD 20892, USA;
| | - Xu Feng
- Retired from National Cancer Institute, Bethesda, MD 20892, USA;
| | - Gaku Nakato
- Kanagawa Institute of Industrial Science and Technology, Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa 210-0821, Japan;
| | - Mark C. Udey
- Dermatology Division, Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Correspondence: (C.-J.W.); (M.C.U.); Tel.: +1-301-760-7452 (C.-J.W.); +1-314-454-8547 (M.C.U.)
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14
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Piontek J, Krug SM, Protze J, Krause G, Fromm M. Molecular architecture and assembly of the tight junction backbone. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183279. [PMID: 32224152 DOI: 10.1016/j.bbamem.2020.183279] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/16/2020] [Accepted: 03/19/2020] [Indexed: 12/18/2022]
Abstract
The functional and structural concept of tight junctions has developed after discovery of claudin and TAMP proteins. Many of these proteins contribute to epi- and endothelial barrier but some, in contrast, form paracellular channels. Claudins form the backbone of tight junction (TJ) strands whereas other proteins regulate TJ dynamics. The current joined double-row model of TJ strands and channels is crucially based on the linear alignment of claudin-15 in the crystal. Molecular dynamics simulations, protein docking, mutagenesis, cellular TJ reconstitution, and electron microscopy studies largely support stability and functionality of the model. Here, we summarize in silico and in vitro data about TJ strand assembly including comparison of claudin crystal structures and alternative models. Sequence comparisons, experimental and structural data substantiate differentiation of classic and non-classic claudins differing in motifs related to strand assembly. Classic claudins seem to share a similar mechanism of strand formation. Interface variations likely contribute to TJ strand flexibility. Combined in vitro/in silico studies are expected to elucidate mechanistic keys determining TJ regulation.
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Affiliation(s)
- Jörg Piontek
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany
| | - Susanne M Krug
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany
| | - Jonas Protze
- Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Gerd Krause
- Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Michael Fromm
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany.
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15
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Assembly of Tight Junction Strands: Claudin-10b and Claudin-3 Form Homo-Tetrameric Building Blocks that Polymerise in a Channel-Independent Manner. J Mol Biol 2020; 432:2405-2427. [DOI: 10.1016/j.jmb.2020.02.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 02/12/2020] [Accepted: 02/28/2020] [Indexed: 02/03/2023]
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16
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Abstract
People worldwide are living longer, and it is estimated that by 2050, the proportion of the world's population over 60 years of age will nearly double. Natural lung aging is associated with molecular and physiological changes that cause alterations in lung function, diminished pulmonary remodeling and regenerative capacity, and increased susceptibility to acute and chronic lung diseases. As the aging population rapidly grows, it is essential to examine how alterations in cellular function and cell-to-cell interactions of pulmonary resident cells and systemic immune cells contribute to a higher risk of increased susceptibility to infection and development of chronic diseases, such as chronic obstructive pulmonary disease and interstitial pulmonary fibrosis. This review provides an overview of physiological, structural, and cellular changes in the aging lung and immune system that facilitate the development and progression of disease.
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Affiliation(s)
- Soo Jung Cho
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA;
| | - Heather W Stout-Delgado
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA;
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17
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Rajagopal N, Irudayanathan FJ, Nangia S. Computational Nanoscopy of Tight Junctions at the Blood-Brain Barrier Interface. Int J Mol Sci 2019; 20:E5583. [PMID: 31717316 PMCID: PMC6888702 DOI: 10.3390/ijms20225583] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/05/2019] [Accepted: 11/06/2019] [Indexed: 12/16/2022] Open
Abstract
The selectivity of the blood-brain barrier (BBB) is primarily maintained by tight junctions (TJs), which act as gatekeepers of the paracellular space by blocking blood-borne toxins, drugs, and pathogens from entering the brain. The BBB presents a significant challenge in designing neurotherapeutics, so a comprehensive understanding of the TJ architecture can aid in the design of novel therapeutics. Unraveling the intricacies of TJs with conventional experimental techniques alone is challenging, but recently developed computational tools can provide a valuable molecular-level understanding of TJ architecture. We employed the computational methods toolkit to investigate claudin-5, a highly expressed TJ protein at the BBB interface. Our approach started with the prediction of claudin-5 structure, evaluation of stable dimer conformations and nanoscale assemblies, followed by the impact of lipid environments, and posttranslational modifications on these claudin-5 assemblies. These led to the study of TJ pores and barriers and finally understanding of ion and small molecule transport through the TJs. Some of these in silico, molecular-level findings, will need to be corroborated by future experiments. The resulting understanding can be advantageous towards the eventual goal of drug delivery across the BBB. This review provides key insights gleaned from a series of state-of-the-art nanoscale simulations (or computational nanoscopy studies) performed on the TJ architecture.
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Affiliation(s)
| | | | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY 13244, USA
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18
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Van Itallie CM, Lidman KF, Tietgens AJ, Anderson JM. Newly synthesized claudins but not occludin are added to the basal side of the tight junction. Mol Biol Cell 2019; 30:1406-1424. [PMID: 30943107 PMCID: PMC6724697 DOI: 10.1091/mbc.e19-01-0008] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A network of claudin strands creates continuous cell–cell contacts to form the intercellular tight junction barrier; a second protein, occludin, is associated along these strands. The physiological barrier remains stable despite protein turnover, which involves removal and replacement of claudins both in the steady state and during junction remodeling. Here we use a pulse–block–pulse labeling protocol with fluorescent ligands to label SNAP/CLIP-tags fused to claudins and occludin to identify their spatial trafficking pathways and kinetics in Madin–Darby canine kidney monolayers. We find that claudins are first delivered to the lateral membrane and, over time, enter the junction strand network from the basal side; this is followed by slow replacement of older claudins in the strands. In contrast, even at early times, newly synthesized occludin is found throughout the network. Taking the results together with our previous documentation of the mechanism for claudin strand assembly in a fibroblast model, we speculate that newly synthesized claudins are added at strand breaks and free ends; these are most common in the basalmost edge of the junction. In contrast, occludin can be added directly within the strand network. We further demonstrate that claudin trafficking and half-life depend on carboxy-terminal sequences and that different claudins compete for tight junction localization.
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Affiliation(s)
- Christina M Van Itallie
- Laboratory of Tight Junction Structure and Function, National Institutes of Health, Bethesda, MD 20892
| | - Karin Fredriksson Lidman
- Laboratory of Tight Junction Structure and Function, National Institutes of Health, Bethesda, MD 20892
| | - Amber Jean Tietgens
- Laboratory of Tight Junction Structure and Function, National Institutes of Health, Bethesda, MD 20892
| | - James Melvin Anderson
- Laboratory of Tight Junction Structure and Function, National Institutes of Health, Bethesda, MD 20892
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19
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Rajagopal N, Irudayanathan FJ, Nangia S. Palmitoylation of Claudin-5 Proteins Influences Their Lipid Domain Affinity and Tight Junction Assembly at the Blood–Brain Barrier Interface. J Phys Chem B 2019; 123:983-993. [DOI: 10.1021/acs.jpcb.8b09535] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Nandhini Rajagopal
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse 13244, United States
| | | | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse 13244, United States
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20
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Belardi B, Son S, Vahey MD, Wang J, Hou J, Fletcher DA. Claudin-4 reconstituted in unilamellar vesicles is sufficient to form tight interfaces that partition membrane proteins. J Cell Sci 2018; 132:jcs.221556. [PMID: 30209136 DOI: 10.1242/jcs.221556] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 09/01/2018] [Indexed: 01/05/2023] Open
Abstract
Tight junctions have been hypothesized to act as molecular fences in the plasma membrane of epithelial cells, helping to form differentiated apical and basolateral domains. While this fence function is believed to arise from the interaction of four-pass transmembrane claudins, the complexity of tight junctions has made direct evidence of their role as a putative diffusion barrier difficult to obtain. Here, we address this challenge by reconstituting claudin-4 into giant unilamellar vesicles using microfluidic jetting. We find that reconstituted claudin-4 alone can form adhesive membrane interfaces without the accessory proteins that are present in vivo By controlling the molecular composition of the inner and outer leaflets of jetted vesicle membranes, we show that claudin-4-mediated interfaces can drive partitioning of extracellular membrane proteins with ectodomains as small as 5 nm but not of inner or outer leaflet lipids. Our findings indicate that homotypic interactions of claudins and their small size can contribute to the polarization of epithelial cells.
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Affiliation(s)
- Brian Belardi
- Department of Bioengineering and Biophysics Program, University of California, Berkeley, CA 94720, USA
| | - Sungmin Son
- Department of Bioengineering and Biophysics Program, University of California, Berkeley, CA 94720, USA
| | - Michael D Vahey
- Department of Bioengineering and Biophysics Program, University of California, Berkeley, CA 94720, USA
| | - Jinzhi Wang
- Department of Internal Medicine & Center for Investigation of Membrane Excitability Disease, Washington University Medical School, St. Louis, MO 63110, USA
| | - Jianghui Hou
- Department of Internal Medicine & Center for Investigation of Membrane Excitability Disease, Washington University Medical School, St. Louis, MO 63110, USA
| | - Daniel A Fletcher
- Department of Bioengineering and Biophysics Program, University of California, Berkeley, CA 94720, USA .,Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.,Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
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21
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Curto MÁ, Moro S, Yanguas F, Gutiérrez-González C, Valdivieso MH. The ancient claudin Dni2 facilitates yeast cell fusion by compartmentalizing Dni1 into a membrane subdomain. Cell Mol Life Sci 2018; 75:1687-1706. [PMID: 29134248 PMCID: PMC11105288 DOI: 10.1007/s00018-017-2709-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 10/10/2017] [Accepted: 11/03/2017] [Indexed: 12/20/2022]
Abstract
Dni1 and Dni2 facilitate cell fusion during mating. Here, we show that these proteins are interdependent for their localization in a plasma membrane subdomain, which we have termed the mating fusion domain. Dni1 compartmentation in the domain is required for cell fusion. The contribution of actin, sterol-dependent membrane organization, and Dni2 to this compartmentation was analysed, and the results showed that Dni2 plays the most relevant role in the process. In turn, the Dni2 exit from the endoplasmic reticulum depends on Dni1. These proteins share the presence of a cysteine motif in their first extracellular loop related to the claudin GLWxxC(8-10 aa)C signature motif. Structure-function analyses show that mutating each Dni1 conserved cysteine has mild effects, and that only simultaneous elimination of several cysteines leads to a mating defect. On the contrary, eliminating each single cysteine and the C-terminal tail in Dni2 abrogates Dni1 compartmentation and cell fusion. Sequence alignments show that claudin trans-membrane helixes bear small-XXX-small motifs at conserved positions. The fourth Dni2 trans-membrane helix tends to form homo-oligomers in Escherichia plasma membrane, and two concatenated small-XXX-small motifs are required for efficient oligomerization and for Dni2 export from the yeast endoplasmic reticulum. Together, our results strongly suggest that Dni2 is an ancient claudin that blocks Dni1 diffusion from the intercellular region where two plasma membranes are in close proximity, and that this function is required for Dni1 to facilitate cell fusion.
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Affiliation(s)
- M-Ángeles Curto
- Departamento de Microbiología y Genética, Universidad de Salamanca, Calle Zacarías González 2, Lab P1.1, Edificio IBFG, 37007, Salamanca, Spain
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas (CSIC), Calle Zacarías González 2, 37007, Salamanca, Spain
| | - Sandra Moro
- Departamento de Microbiología y Genética, Universidad de Salamanca, Calle Zacarías González 2, Lab P1.1, Edificio IBFG, 37007, Salamanca, Spain
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas (CSIC), Calle Zacarías González 2, 37007, Salamanca, Spain
| | - Francisco Yanguas
- Departamento de Microbiología y Genética, Universidad de Salamanca, Calle Zacarías González 2, Lab P1.1, Edificio IBFG, 37007, Salamanca, Spain
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas (CSIC), Calle Zacarías González 2, 37007, Salamanca, Spain
| | - Carmen Gutiérrez-González
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas (CSIC), Calle Zacarías González 2, 37007, Salamanca, Spain
| | - M-Henar Valdivieso
- Departamento de Microbiología y Genética, Universidad de Salamanca, Calle Zacarías González 2, Lab P1.1, Edificio IBFG, 37007, Salamanca, Spain.
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas (CSIC), Calle Zacarías González 2, 37007, Salamanca, Spain.
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22
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Lv J, Hu W, Yang Z, Li T, Jiang S, Ma Z, Chen F, Yang Y. Focusing on claudin-5: A promising candidate in the regulation of BBB to treat ischemic stroke. Prog Neurobiol 2017; 161:79-96. [PMID: 29217457 DOI: 10.1016/j.pneurobio.2017.12.001] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/20/2017] [Accepted: 12/03/2017] [Indexed: 12/11/2022]
Abstract
Claudin-5 is a tight junction (TJ) protein in the blood-brain barrier (BBB) that has recently attracted increased attention. Numerous studies have demonstrated that claudin-5 regulates the integrity and permeability of the BBB. Increased claudin-5 expression plays a neuroprotective role in neurological diseases, particularly in cerebral ischemic stroke. Moreover, claudin-5 might be a potential marker for early hemorrhagic transformation detection in ischemic stroke. In light of the distinctive effects of claudin-5 on the nervous system, we present the elaborate network of roles that claudin-5 plays in ischemic stroke. In this review, we first introduce basic knowledge regarding the BBB and the claudin family, the characterization and regulation of claudin-5, and association between claudin-5 and other TJ proteins. Subsequently, we describe BBB dysfunction and neuron-specific drivers of pathogenesis of ischemic stroke, including inflammatory disequilibrium and oxidative stress. Furthermore, we summarize promising ischemic stroke treatments that target the BBB via claudin-5, including modified rt-PA therapy, pharmacotherapy, hormone treatment, receptor-targeted therapy, gene therapy, and physical therapy. This review highlights recent advances and provides a comprehensive summary of claudin-5 in the regulation of the BBB and may be helpful for drug design and clinical therapy for treatment of ischemic stroke.
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Affiliation(s)
- Jianjun Lv
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences, Northwest University, 229 Taibai North Road, Xi'an 710069, China; Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Wei Hu
- Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China; Department of Immunology, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Zhi Yang
- Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Tian Li
- Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Shuai Jiang
- Department of Aerospace Medicine, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Zhiqiang Ma
- Department of Thoracic Surgery, Tangdu Hospital, The Fourth Military Medical University, 1 Xinsi Road, Xi'an 710038, China
| | - Fulin Chen
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences, Northwest University, 229 Taibai North Road, Xi'an 710069, China
| | - Yang Yang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences, Northwest University, 229 Taibai North Road, Xi'an 710069, China; Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China.
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23
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Abstract
BACKGROUND Intestinal barrier defects are common in patients with inflammatory bowel disease (IBD). To identify which components could underlie these changes, we performed an in-depth analysis of epithelial barrier genes in IBD. METHODS A set of 128 intestinal barrier genes was selected. Polygenic risk scores were generated based on selected barrier gene variants that were associated with Crohn's disease (CD) or ulcerative colitis (UC) in our study. Gene expression was analyzed using microarray and quantitative reverse transcription polymerase chain reaction. Influence of barrier gene variants on expression was studied by cis-expression quantitative trait loci mapping and comparing patients with low- and high-risk scores. RESULTS Barrier risk scores were significantly higher in patients with IBD than controls. At single-gene level, the associated barrier single-nucleotide polymorphisms were most significantly enriched in PTGER4 for CD and HNF4A for UC. As a group, the regulating proteins were most enriched for CD and UC. Expression analysis showed that many epithelial barrier genes were significantly dysregulated in active CD and UC, with overrepresentation of mucus layer genes. In uninflamed CD ileum and IBD colon, most barrier gene levels restored to normal, except for MUC1 and MUC4 that remained persistently increased compared with controls. Expression levels did not depend on cis-regulatory variants nor combined genetic risk. CONCLUSIONS We found genetic and transcriptomic dysregulations of key epithelial barrier genes and components in IBD. Of these, we believe that mucus genes, in particular MUC1 and MUC4, play an essential role in the pathogenesis of IBD and could represent interesting targets for treatment.
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24
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Lin D, Guo Y, Li Y, Ruan Y, Zhang M, Jin X, Yang M, Lu Y, Song P, Zhao S, Dong B, Xie Y, Dang Q, Quan C. Bioinformatic analysis reveals potential properties of human Claudin-6 regulation and functions. Oncol Rep 2017; 38:875-885. [PMID: 28656265 PMCID: PMC5561977 DOI: 10.3892/or.2017.5756] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Accepted: 05/31/2017] [Indexed: 12/11/2022] Open
Abstract
Claudin-6 (CLDN6) is an integral component of the tight junction proteins in polarized epithelial and endothelial cells and plays a crucial role in maintaining cell integrity. Deregulation of CLDN6 expression and distribution in tumor tissues have been widely documented and correlated with cancer progression and metastasis. However, a complete mechanistic understanding of CLDN6 regulation and function remains to be studied. Herein, we show new potential properties of CLDN6 regulation and functions from bioinformatics analysis. Using numerous algorithms to characterize the CLDN6 gene promoter elements and the CLDN6 protein structure, physio-chemical and localization properties, and its evolutionary relationships. CLDN6 is regulated by a diverse set of transcription factors (SP1, SPR, AML-1a, CdxA, CRE-BP and CREB) and associated with the levels of methylation of CpG islands in promoters. The structural properties of CLDN6 indicate that it promotes cancer cell behavior via the ASK1-p38/JNK MAPK secretory signaling pathway. In conclusion, this information from bioinformatics analysis will help future attempts to better understand CLDN6 regulation and functions.
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Affiliation(s)
- Dongjing Lin
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Yaxiong Guo
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Yanru Li
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Yang Ruan
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Mingzi Zhang
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Xiangshu Jin
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Minlan Yang
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Yan Lu
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Peiye Song
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Shuai Zhao
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Bing Dong
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Yinping Xie
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Qihua Dang
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
| | - Chengshi Quan
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130000, P.R. China
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25
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Cornely RM, Schlingmann B, Shepherd WS, Chandler JD, Neujahr DC, Koval M. Two common human CLDN5 alleles encode different open reading frames but produce one protein isoform. Ann N Y Acad Sci 2017; 1397:119-129. [PMID: 28445614 DOI: 10.1111/nyas.13342] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 02/28/2017] [Accepted: 03/01/2017] [Indexed: 01/07/2023]
Abstract
Claudins provide tight junction barrier selectivity. The human CLDN5 gene contains a high-frequency single-nucleotide polymorphism (rs885985), where the G allele codes for glutamine (Q) and the A allele codes for an amber stop codon. Thus, these different CLDN5 alleles define nested open reading frames (ORFs) encoding claudin-5 proteins that are 303 or 218 amino acids in length. Interestingly, human claudin-16 and claudin-23 also have long ORFs. The long form of claudin-5 contrasts with the majority of claudin-5 proteins in the National Center for Biotechnology Information protein database, which are less than 220 amino acids in length. Screening of genotyped human lung tissue by immunoblot revealed only the 218 amino acid form of claudin-5 protein; the long-form claudin-5 protein was not detected. Moreover, when forcibly expressed in transfected cells, the long form of human claudin-5 was retained in intracellular compartments and did not localize to the plasma membrane, in contrast to the 218 amino acid form, which localized to intercellular junctions. This suggests that the 303 amino acid claudin-5 protein is rarely expressed, and, if so, is predicted to adversely affect cell function. Potential roles for upstream ORFs in regulating claudin-5 expression are also discussed.
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Affiliation(s)
- Ronald M Cornely
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Barbara Schlingmann
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Whitney S Shepherd
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Joshua D Chandler
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - David C Neujahr
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,McKelvey Lung Transplant Center, Emory University School of Medicine, Atlanta, Georgia
| | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia.,Emory+Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, Georgia
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26
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Van Itallie CM, Tietgens AJ, Anderson JM. Visualizing the dynamic coupling of claudin strands to the actin cytoskeleton through ZO-1. Mol Biol Cell 2016; 28:524-534. [PMID: 27974639 PMCID: PMC5305259 DOI: 10.1091/mbc.e16-10-0698] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 11/28/2016] [Accepted: 12/09/2016] [Indexed: 01/27/2023] Open
Abstract
The organization and integrity of epithelial tight junctions depend on interactions between claudins, ZO scaffolding proteins, and the cytoskeleton. However, although binding between claudins and ZO-1/2/3 and between ZO-1/2/3 and numerous cytoskeletal proteins has been demonstrated in vitro, fluorescence recovery after photobleaching analysis suggests interactions in vivo are likely highly dynamic. Here we use superresolution live-cell imaging in a model fibroblast system to examine relationships between claudins, ZO-1, occludin, and actin. We find that GFP claudins make easily visualized dynamic strand patches between two fibroblasts; strand dynamics is constrained by ZO-1 binding. Claudin association with actin is also dependent on ZO-1, but colocalization demonstrates intermittent rather than continuous association between claudin, ZO-1, and actin. Independent of interaction with ZO-1 or actin, claudin strands break and reanneal; pulse-chase-pulse analysis using SNAP-tagged claudins showed preferential incorporation of newly synthesized claudins into break sites. Although claudin strand behavior in fibroblasts may not fully recapitulate that of epithelial tight junction strands, this is the first direct demonstration of the ability of ZO-1 to stabilize claudin strands. We speculate that intermittent tethering of claudins to actin may allow for accommodation of the paracellular seal to physiological or pathological alterations in cell shape or movement.
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Affiliation(s)
- Christina M Van Itallie
- Laboratory of Tight Junction Structure and Function, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Amber Jean Tietgens
- Laboratory of Tight Junction Structure and Function, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - James M Anderson
- Laboratory of Tight Junction Structure and Function, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
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27
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Luissint AC, Parkos CA, Nusrat A. Inflammation and the Intestinal Barrier: Leukocyte-Epithelial Cell Interactions, Cell Junction Remodeling, and Mucosal Repair. Gastroenterology 2016; 151:616-32. [PMID: 27436072 PMCID: PMC5317033 DOI: 10.1053/j.gastro.2016.07.008] [Citation(s) in RCA: 323] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 06/13/2016] [Accepted: 07/06/2016] [Indexed: 02/06/2023]
Abstract
The intestinal tract is lined by a single layer of columnar epithelial cells that forms a dynamic, permeable barrier allowing for selective absorption of nutrients, while restricting access to pathogens and food-borne antigens. Precise regulation of epithelial barrier function is therefore required for maintaining mucosal homeostasis and depends, in part, on barrier-forming elements within the epithelium and a balance between pro- and anti-inflammatory factors in the mucosa. Pathologic states, such as inflammatory bowel disease, are associated with a leaky epithelial barrier, resulting in excessive exposure to microbial antigens, recruitment of leukocytes, release of soluble mediators, and ultimately mucosal damage. An inflammatory microenvironment affects epithelial barrier properties and mucosal homeostasis by altering the structure and function of epithelial intercellular junctions through direct and indirect mechanisms. We review our current understanding of complex interactions between the intestinal epithelium and immune cells, with a focus on pathologic mucosal inflammation and mechanisms of epithelial repair. We discuss leukocyte-epithelial interactions, as well as inflammatory mediators that affect the epithelial barrier and mucosal repair. Increased knowledge of communication networks between the epithelium and immune system will lead to tissue-specific strategies for treating pathologic intestinal inflammation.
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Affiliation(s)
| | | | - Asma Nusrat
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan.
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28
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Stammler A, Lüftner BU, Kliesch S, Weidner W, Bergmann M, Middendorff R, Konrad L. Highly Conserved Testicular Localization of Claudin-11 in Normal and Impaired Spermatogenesis. PLoS One 2016; 11:e0160349. [PMID: 27486954 PMCID: PMC4972306 DOI: 10.1371/journal.pone.0160349] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 07/18/2016] [Indexed: 01/13/2023] Open
Abstract
In this study we tested expression of tight junction proteins in human, mouse and rat and analyzed the localization of claudin-11 in testis of patients with normal and impaired spermatogenesis. Recent concepts generated in mice suggest that the stage-specifically expressed claudin-3 acts as a basal barrier, sealing the seminiferous epithelium during migration of spermatocytes. Corresponding mechanisms have never been demonstrated in humans. Testicular biopsies (n = 103) from five distinct groups were analyzed: normal spermatogenesis (NSP, n = 28), hypospermatogenesis (Hyp, n = 24), maturation arrest at the level of primary spermatocytes (MA, n = 24), Sertoli cell only syndrome (SCO, n = 19), and spermatogonial arrest (SGA, n = 8). Protein expression of claudin-3, -11 and occludin was analyzed. Human, mice and rat testis robustly express claudin-11 protein. Occludin was detected in mouse and rat and claudin-3 was found only in mice. Thus, we selected claudin-11 for further analysis of localization. In NSP, claudin-11 is located at Sertoli-Sertoli junctions and in Sertoli cell contacts towards spermatogonia. Typically, claudin-11 patches do not reach the basal membrane, unless flanked by the Sertoli cell body or patches between two Sertoli cell bodies. The amount of basal claudin-11 patches was found to be increased in impaired spermatogenesis. Only claudin-11 is expressed in all three species examined. The claudin-11 pattern is robust in man with impaired spermatogenesis, but the proportion of localization is altered in SCO and MA. We conclude that claudin-11 might represent the essential component of the BTB in human.
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Affiliation(s)
- Angelika Stammler
- Justus-Liebig-University Giessen, Institute of Anatomy and Cell Biology, Aulweg 123, D-35392, Giessen, Germany
- Justus-Liebig-University Giessen, Department of Obstetrics and Gynecology, Feulgenstraße 12, D-35392, Giessen, Germany
| | - Benjamin Udo Lüftner
- Justus-Liebig-University Giessen, Department of Obstetrics and Gynecology, Feulgenstraße 12, D-35392, Giessen, Germany
| | - Sabine Kliesch
- University Hospital Münster, Department of Clinical Andrology, Centre of Reproductive Medicine and Andrology, Domagkstrasse 11, D-48129, Münster, Germany
| | - Wolfgang Weidner
- Justus-Liebig-University / UKGM Giessen, Department of Urology, Pediatric Urology and Andrology, D-35392 Giessen, Germany
| | - Martin Bergmann
- Justus-Liebig-University Giessen, Institute of Veterinary Anatomy, Histology and Embryology, Frankfurter Straße 98, D-35392, Giessen, Germany
| | - Ralf Middendorff
- Justus-Liebig-University Giessen, Institute of Anatomy and Cell Biology, Aulweg 123, D-35392, Giessen, Germany
| | - Lutz Konrad
- Justus-Liebig-University Giessen, Department of Obstetrics and Gynecology, Feulgenstraße 12, D-35392, Giessen, Germany
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29
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Schlingmann B, Overgaard CE, Molina SA, Lynn KS, Mitchell LA, Dorsainvil White S, Mattheyses AL, Guidot DM, Capaldo CT, Koval M. Regulation of claudin/zonula occludens-1 complexes by hetero-claudin interactions. Nat Commun 2016; 7:12276. [PMID: 27452368 PMCID: PMC4962485 DOI: 10.1038/ncomms12276] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/15/2016] [Indexed: 01/06/2023] Open
Abstract
Claudins are tetraspan transmembrane tight-junction proteins that regulate epithelial barriers. In the distal airspaces of the lung, alveolar epithelial tight junctions are crucial to regulate airspace fluid. Chronic alcohol abuse weakens alveolar tight junctions, priming the lung for acute respiratory distress syndrome, a frequently lethal condition caused by airspace flooding. Here we demonstrate that in response to alcohol, increased claudin-5 paradoxically accompanies an increase in paracellular leak and rearrangement of alveolar tight junctions. Claudin-5 is necessary and sufficient to diminish alveolar epithelial barrier function by impairing the ability of claudin-18 to interact with a scaffold protein, zonula occludens 1 (ZO-1), demonstrating that one claudin affects the ability of another claudin to interact with the tight-junction scaffold. Critically, a claudin-5 peptide mimetic reverses the deleterious effects of alcohol on alveolar barrier function. Thus, claudin controlled claudin-scaffold protein interactions are a novel target to regulate tight-junction permeability.
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Affiliation(s)
- Barbara Schlingmann
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA
| | - Christian E Overgaard
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA
| | - Samuel A Molina
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA
| | - K Sabrina Lynn
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA
| | - Leslie A Mitchell
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA
| | - StevenClaude Dorsainvil White
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA
| | - Alexa L Mattheyses
- Department of Cell Biology, Emory University, Atlanta, Georgia 30322, USA
| | - David M Guidot
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA.,Atlanta Veterans Affairs Medical Center, Decatur, Georgia 30033, USA
| | - Christopher T Capaldo
- Department of Pathology; Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA.,Department of Cell Biology, Emory University, Atlanta, Georgia 30322, USA
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30
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Lili LN, Farkas AE, Gerner-Smidt C, Overgaard CE, Moreno CS, Parkos CA, Capaldo CT, Nusrat A. Claudin-based barrier differentiation in the colonic epithelial crypt niche involves Hopx/Klf4 and Tcf7l2/Hnf4-α cascades. Tissue Barriers 2016; 4:e1214038. [PMID: 27583195 DOI: 10.1080/21688370.2016.1214038] [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: 06/22/2016] [Revised: 07/11/2016] [Accepted: 07/11/2016] [Indexed: 12/13/2022] Open
Abstract
Colonic enterocytes form a rapidly renewing epithelium and barrier to luminal antigens. During renewal, coordinated expression of the claudin family of genes is vital to maintain the epithelial barrier. Disruption of this process contributes to barrier compromise and mucosal inflammatory diseases. However, little is known about the regulation of this critical aspect of epithelial cell differentiation. In order to identify claudin regulatory factors we utilized high-throughput gene microarrays and correlation analyses. We identified complex expression gradients for the transcription factors Hopx, Hnf4a, Klf4 and Tcf7l2, as well as 12 claudins, during differentiation. In vitro confirmatory methods identified 2 pathways that stimulate claudin expression; Hopx/Klf4 activation of Cldn4, 7 and 15, and Tcf7l2/Hnf4a up-regulation of Cldn23. Chromatin immunoprecipitation confirmed a Tcf7l2/Hnf4a/Claudin23 cascade. Furthermore, Hnf4a conditional knockout mice fail to induce Cldn23 during colonocyte differentiation. In conclusion, we report a comprehensive screen of colonic claudin gene expression and discover spatiotemporal Hopx/Klf4 and Tcf7l2/Hnf4a signaling as stimulators of colonic epithelial barrier differentiation.
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Affiliation(s)
- Loukia N Lili
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine , Atlanta, GA, USA
| | - Attila E Farkas
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA; Institute of Biophysics, Biological Research Center, Szeged, Hungary
| | - Christian Gerner-Smidt
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine , Atlanta, GA, USA
| | | | - Carlos S Moreno
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine , Atlanta, GA, USA
| | - Charles A Parkos
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA; Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | | | - Asma Nusrat
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA; Department of Pathology, University of Michigan, Ann Arbor, MI, USA
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31
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Kielgast F, Schmidt H, Braubach P, Winkelmann VE, Thompson KE, Frick M, Dietl P, Wittekindt OH. Glucocorticoids Regulate Tight Junction Permeability of Lung Epithelia by Modulating Claudin 8. Am J Respir Cell Mol Biol 2016; 54:707-17. [DOI: 10.1165/rcmb.2015-0071oc] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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32
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Shrestha A, Uzal FA, McClane BA. The interaction of Clostridium perfringens enterotoxin with receptor claudins. Anaerobe 2016; 41:18-26. [PMID: 27090847 DOI: 10.1016/j.anaerobe.2016.04.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/07/2016] [Accepted: 04/15/2016] [Indexed: 01/30/2023]
Abstract
Clostridium perfringens enterotoxin (CPE) has significant medical importance due to its involvement in several common human gastrointestinal diseases. This 35 kDa single polypeptide toxin consists of two domains: a C-terminal domain involved in receptor binding and an N-terminal domain involved in oligomerization, membrane insertion and pore formation. The action of CPE starts with its binding to receptors, which include certain members of the claudin tight junction protein family; bound CPE then forms a series of complexes, one of which is a pore that causes the calcium influx responsible for host cell death. Recent studies have revealed that CPE binding to claudin receptors involves interactions between the C-terminal CPE domain and both the 1st and 2nd extracellular loops (ECL-1 and ECL-2) of claudin receptors. Of particular importance for this binding is the docking of ECL-2 into a pocket present in the C-terminal domain of the toxin. This increased understanding of CPE interactions with claudin receptors is now fostering the development of receptor decoy therapeutics for CPE-mediated gastrointestinal disease, reagents for cancer therapy/diagnoses and enhancers of drug delivery.
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Affiliation(s)
- Archana Shrestha
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Francisco A Uzal
- California Animal Health and Food Safety Laboratory, San Bernadino Branch, School of Veterinary Medicine, University of California-Davis, USA
| | - Bruce A McClane
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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33
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Naydenov NG, Feygin A, Wang D, Kuemmerle JF, Harris G, Conti MA, Adelstein RS, Ivanov AI. Nonmuscle Myosin IIA Regulates Intestinal Epithelial Barrier in vivo and Plays a Protective Role During Experimental Colitis. Sci Rep 2016; 6:24161. [PMID: 27063635 PMCID: PMC4827066 DOI: 10.1038/srep24161] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/21/2016] [Indexed: 02/07/2023] Open
Abstract
The actin cytoskeleton is a critical regulator of intestinal mucosal barrier permeability, and the integrity of epithelial adherens junctions (AJ) and tight junctions (TJ). Non muscle myosin II (NM II) is a key cytoskeletal motor that controls actin filament architecture and dynamics. While NM II has been implicated in the regulation of epithelial junctions in vitro, little is known about its roles in the intestinal mucosa in vivo. In this study, we generated a mouse model with an intestinal epithelial-specific knockout of NM IIA heavy chain (NM IIA cKO) and examined the structure and function of normal gut barrier, and the development of experimental colitis in these animals. Unchallenged NM IIA cKO mice showed increased intestinal permeability and altered expression/localization of several AJ/TJ proteins. They did not develop spontaneous colitis, but demonstrated signs of a low-scale mucosal inflammation manifested by prolapses, lymphoid aggregates, increased cytokine expression, and neutrophil infiltration in the gut. NM IIA cKO animals were characterized by a more severe disruption of the gut barrier and exaggerated mucosal injury during experimentally-induced colitis. Our study provides the first evidence that NM IIA plays important roles in establishing normal intestinal barrier, and protection from mucosal inflammation in vivo.
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Affiliation(s)
- Nayden G Naydenov
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA23298
| | - Alex Feygin
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA23298
| | - Dongdong Wang
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA23298
| | - John F Kuemmerle
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298
| | - Gianni Harris
- Department of Medicine, University of Rochester School of Medicine, Rochester, NY
| | - Mary Anne Conti
- Laboratory of Molecular Cardiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892
| | - Robert S Adelstein
- Laboratory of Molecular Cardiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892
| | - Andrei I Ivanov
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA23298.,VCU Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298.,Virginia Institute of Molecular Medicine, Richmond, VA 23298
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34
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Liu F, Koval M, Ranganathan S, Fanayan S, Hancock WS, Lundberg EK, Beavis RC, Lane L, Duek P, McQuade L, Kelleher NL, Baker MS. Systems Proteomics View of the Endogenous Human Claudin Protein Family. J Proteome Res 2016; 15:339-59. [PMID: 26680015 DOI: 10.1021/acs.jproteome.5b00769] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Claudins are the major transmembrane protein components of tight junctions in human endothelia and epithelia. Tissue-specific expression of claudin members suggests that this protein family is not only essential for sustaining the role of tight junctions in cell permeability control but also vital in organizing cell contact signaling by protein-protein interactions. How this protein family is collectively processed and regulated is key to understanding the role of junctional proteins in preserving cell identity and tissue integrity. The focus of this review is to first provide a brief overview of the functional context, on the basis of the extensive body of claudin biology research that has been thoroughly reviewed, for endogenous human claudin members and then ascertain existing and future proteomics techniques that may be applicable to systematically characterizing the chemical forms and interacting protein partners of this protein family in human. The ability to elucidate claudin-based signaling networks may provide new insight into cell development and differentiation programs that are crucial to tissue stability and manipulation.
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Affiliation(s)
| | - Michael Koval
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, and Department of Cell Biology, Emory University School of Medicine , 205 Whitehead Biomedical Research Building, 615 Michael Street, Atlanta, Georgia 30322, United States
| | | | | | - William S Hancock
- Barnett Institute and Department of Chemistry and Chemical Biology, Northeastern University , Boston, Massachusetts 02115, United States
| | - Emma K Lundberg
- SciLifeLab, School of Biotechnology, Royal Institute of Technology (KTH) , SE-171 21 Solna, Stockholm, Sweden
| | - Ronald C Beavis
- Department of Biochemistry and Medical Genetics, University of Manitoba , 744 Bannatyne Avenue, Winnipeg, Manitoba R3E 0W3, Canada
| | - Lydie Lane
- SIB-Swiss Institute of Bioinformatics , CMU - Rue Michel-Servet 1, 1211 Geneva, Switzerland
| | - Paula Duek
- SIB-Swiss Institute of Bioinformatics , CMU - Rue Michel-Servet 1, 1211 Geneva, Switzerland
| | | | - Neil L Kelleher
- Department of Chemistry, Department of Molecular Biosciences, and Proteomics Center of Excellence, Northwestern University , 2145 North Sheridan Road, Evanston, Illinois 60208, United States
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35
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Capaldo CT, Nusrat A. Claudin switching: Physiological plasticity of the Tight Junction. Semin Cell Dev Biol 2015; 42:22-9. [PMID: 25957515 DOI: 10.1016/j.semcdb.2015.04.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 04/15/2015] [Accepted: 04/16/2015] [Indexed: 01/22/2023]
Abstract
Tight Junctions (TJs) are multi-molecular complexes in epithelial tissues that regulate paracellular permeability. Within the TJ complex, claudins proteins span the paracellular space to form a seal between adjacent cells. This seal allows regulated passage of ions, fluids, and solutes, contingent upon the complement of claudins expressed. With as many as 27 claudins in the human genome, the TJ seal is complex indeed. This review focuses on changes in claudin expression within the epithelial cells of the gastrointestinal tract, where claudin differentiation results in several physiologically distinct TJs within the lifetime of the cell. We also review mechanistic studies revealing that TJs are highly dynamic, with the potential to undergo molecular remodeling while structurally intact. Therefore, physiologic Tight Junction plasticity involves both the adaptability of claudin expression and gene specific retention in the TJ; a process we term claudin switching.
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Affiliation(s)
- Christopher T Capaldo
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, United States
| | - Asma Nusrat
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, United States; Department of Pathology, University of Michigan, Ann Arbor, MI 48109, United States.
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36
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Assembly and function of claudins: Structure–function relationships based on homology models and crystal structures. Semin Cell Dev Biol 2015; 42:3-12. [DOI: 10.1016/j.semcdb.2015.04.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 04/28/2015] [Accepted: 04/29/2015] [Indexed: 01/12/2023]
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37
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Lechuga S, Baranwal S, Ivanov AI. Actin-interacting protein 1 controls assembly and permeability of intestinal epithelial apical junctions. Am J Physiol Gastrointest Liver Physiol 2015; 308:G745-56. [PMID: 25792565 PMCID: PMC4421013 DOI: 10.1152/ajpgi.00446.2014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/11/2015] [Indexed: 01/31/2023]
Abstract
Adherens junctions (AJs) and tight junctions (TJs) are crucial regulators of the integrity and restitution of the intestinal epithelial barrier. The structure and function of epithelial junctions depend on their association with the cortical actin cytoskeleton that, in polarized epithelial cells, is represented by a prominent perijunctional actomyosin belt. The assembly and stability of the perijunctional cytoskeleton is controlled by constant turnover (disassembly and reassembly) of actin filaments. Actin-interacting protein (Aip) 1 is an emerging regulator of the actin cytoskeleton, playing a critical role in filament disassembly. In this study, we examined the roles of Aip1 in regulating the structure and remodeling of AJs and TJs in human intestinal epithelium. Aip1 was enriched at apical junctions in polarized human intestinal epithelial cells and normal mouse colonic mucosa. Knockdown of Aip1 by RNA interference increased the paracellular permeability of epithelial cell monolayers, decreased recruitment of AJ/TJ proteins to steady-state intercellular contacts, and attenuated junctional reassembly in a calcium-switch model. The observed defects of AJ/TJ structure and functions were accompanied by abnormal organization and dynamics of the perijunctional F-actin cytoskeleton. Moreover, loss of Aip1 impaired the apico-basal polarity of intestinal epithelial cell monolayers and inhibited formation of polarized epithelial cysts in 3-D Matrigel. Our findings demonstrate a previously unanticipated role of Aip1 in regulating the structure and remodeling of intestinal epithelial junctions and early steps of epithelial morphogenesis.
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Affiliation(s)
- Susana Lechuga
- 1Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia;
| | - Somesh Baranwal
- 1Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia;
| | - Andrei I. Ivanov
- 1Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia; ,2Virginia Institute of Molecular Medicine, Virginia Commonwealth University, Richmond, Virginia; ,3VCU Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia
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38
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Overgaard CE, Schlingmann B, Dorsainvil White S, Ward C, Fan X, Swarnakar S, Brown LAS, Guidot DM, Koval M. The relative balance of GM-CSF and TGF-β1 regulates lung epithelial barrier function. Am J Physiol Lung Cell Mol Physiol 2015; 308:L1212-23. [PMID: 25888574 DOI: 10.1152/ajplung.00042.2014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/09/2015] [Indexed: 11/22/2022] Open
Abstract
Lung barrier dysfunction is a cardinal feature of the acute respiratory distress syndrome (ARDS). Alcohol abuse, which increases the risk of ARDS two- to fourfold, induces transforming growth factor (TGF)-β1, which increases epithelial permeability and impairs granulocyte/macrophage colony-stimulating factor (GM-CSF)-dependent barrier integrity in experimental models. We hypothesized that the relative balance of GM-CSF and TGF-β1 signaling regulates lung epithelial barrier function. GM-CSF and TGF-β1 were tested separately and simultaneously for their effects on lung epithelial cell barrier function in vitro. TGF-β1 alone caused an ∼ 25% decrease in transepithelial resistance (TER), increased paracellular flux, and was associated with projections perpendicular to tight junctions ("spikes") containing claudin-18 that colocalized with F-actin. In contrast, GM-CSF treatment induced an ∼ 20% increase in TER, decreased paracellular flux, and showed decreased colocalization of spike-associated claudin-18 with F-actin. When simultaneously administered to lung epithelial cells, GM-CSF antagonized the effects of TGF-β1 on epithelial barrier function in cultured cells. Given this, GM-CSF and TGF-β1 levels were measured in bronchoalveolar lavage (BAL) fluid from patients with ventilator-associated pneumonia and correlated with markers for pulmonary edema and patient outcome. In patient BAL fluid, protein markers of lung barrier dysfunction, serum α2-macroglobulin, and IgM levels were increased at lower ratios of GM-CSF/TGF-β1. Critically, patients who survived had significantly higher GM-CSF/TGF-β1 ratios than nonsurviving patients. This study provides experimental and clinical evidence that the relative balance between GM-CSF and TGF-β1 signaling is a key regulator of lung epithelial barrier function. The GM-CSF/TGF-β1 ratio in BAL fluid may provide a concentration-independent biomarker that can predict patient outcomes in ARDS.
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Affiliation(s)
- Christian E Overgaard
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia; Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia
| | - Barbara Schlingmann
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia
| | - StevenClaude Dorsainvil White
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia
| | - Christina Ward
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia; Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia
| | - Xian Fan
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia; Atlanta Veterans Affairs Medical Center, Decatur, Georgia
| | - Snehasikta Swarnakar
- Drug Development Diagnostics and Biotechnology, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Lou Ann S Brown
- Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia; Division of Neonatology, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia
| | - David M Guidot
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia; Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia; Atlanta Veterans Affairs Medical Center, Decatur, Georgia
| | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia; Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia; Department of Cell Biology, Emory University, Atlanta, Georgia;
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Respiratory epithelial cells orchestrate pulmonary innate immunity. Nat Immunol 2015; 16:27-35. [PMID: 25521682 DOI: 10.1038/ni.3045] [Citation(s) in RCA: 478] [Impact Index Per Article: 53.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 10/30/2014] [Indexed: 02/07/2023]
Abstract
The epithelial surfaces of the lungs are in direct contact with the environment and are subjected to dynamic physical forces as airway tubes and alveoli are stretched and compressed during ventilation. Mucociliary clearance in conducting airways, reduction of surface tension in the alveoli, and maintenance of near sterility have been accommodated by the evolution of a multi-tiered innate host-defense system. The biophysical nature of pulmonary host defenses are integrated with the ability of respiratory epithelial cells to respond to and 'instruct' the professional immune system to protect the lungs from infection and injury.
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40
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Dabrowski S, Staat C, Zwanziger D, Sauer RS, Bellmann C, Günther R, Krause E, Haseloff RF, Rittner H, Blasig IE. Redox-sensitive structure and function of the first extracellular loop of the cell-cell contact protein claudin-1: lessons from molecular structure to animals. Antioxid Redox Signal 2015; 22:1-14. [PMID: 24988310 PMCID: PMC4270150 DOI: 10.1089/ars.2013.5706] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
UNLABELLED The paracellular cleft within epithelia/endothelia is sealed by tight junction (TJ) proteins. Their extracellular loops (ECLs) are assumed to control paracellular permeability and are targets of pathogenes. We demonstrated that claudin-1 is crucial for paracellular tightening. Its ECL1 is essential for the sealing and contains two cysteines conserved throughout all claudins. AIMS We prove the hypothesis that this cysteine motif forms a redox-sensitive intramolecular disulfide bridge and, hence, the claudin-1-ECL1 constitutes a functional structure which is associated to ECLs of this and other TJ proteins. RESULTS The structure and function of claudin-1-ECL1 was elucidated by investigating sequences of this ECL as synthetic peptides, C1C2, and as recombinant proteins, and exhibited a β-sheet binding surface flanked by an α-helix. These sequences bound to different claudins, their ECL1, and peptides with nanomolar binding constants. C-terminally truncated C1C2 (-4aaC) opened cellular barriers and the perineurium. Recombinant ECL1 formed oligomers, and bound to claudin-1 expressing cells. Oligomerization and claudin association were abolished by reducing agents, indicating intraloop disulfide bridging and redox sensitivity. INNOVATION The structural and functional model based on our in vitro and in vivo investigations suggested that claudin-1-ECL1 constitutes a functional and ECL-binding β-sheet, stabilized by a shielded and redox-sensitive disulfide bond. CONCLUSION Since the β-sheet represents a consensus sequence of claudins and further junctional proteins, a general structural feature is implied. Therefore, our model is of general relevance for the TJ assembly in normal and pathological conditions. C1C2-4aaC is a new drug enhancer that is used to improve pharmacological treatment through tissue barriers.
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Affiliation(s)
- Sebastian Dabrowski
- 1 Department of Molecular Cell Physiology, Leibniz-Institut für Molekulare Pharmakologie , Berlin, Germany
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Wiechmann AF, Ceresa BP, Howard EW. Diurnal variation of tight junction integrity associates inversely with matrix metalloproteinase expression in Xenopus laevis corneal epithelium: implications for circadian regulation of homeostatic surface cell desquamation. PLoS One 2014; 9:e113810. [PMID: 25412440 PMCID: PMC4239109 DOI: 10.1371/journal.pone.0113810] [Citation(s) in RCA: 13] [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: 09/24/2014] [Accepted: 10/31/2014] [Indexed: 01/08/2023] Open
Abstract
Background and Objectives The corneal epithelium provides a protective barrier against pathogen entrance and abrasive forces, largely due to the intercellular junctional complexes between neighboring cells. After a prescribed duration at the corneal surface, tight junctions between squamous surface cells must be disrupted to enable them to desquamate as a component of the tissue homeostatic renewal. We hypothesize that matrix metalloproteinase (MMPs) are secreted by corneal epithelial cells and cleave intercellular junctional proteins extracellularly at the epithelial surface. The purpose of this study was to examine the expression of specific MMPs and tight junction proteins during both the light and dark phases of the circadian cycle, and to assess their temporal and spatial relationships in the Xenopus laevis corneal epithelium. Methodology/Principal Findings Expression of MMP-2, tissue inhibitor of MMP-2 (TIMP-2), membrane type 1-MMP (MT1-MMP) and the tight junction proteins occludin and claudin-4 were examined by confocal double-label immunohistochemistry on corneas obtained from Xenopus frogs at different circadian times. Occludin and claudin-4 expression was generally uniformly intact on the surface corneal epithelial cell lateral membranes during the daytime, but was frequently disrupted in small clusters of cells at night. Concomitantly, MMP-2 expression was often elevated in a mosaic pattern at nighttime and associated with clusters of desquamating surface cells. The MMP-2 binding partners, TIMP-2 and MT1-MMP were also localized to surface corneal epithelial cells during both the light and dark phases, with TIMP-2 tending to be elevated during the daytime. Conclusions/Significance MMP-2 protein expression is elevated in a mosaic pattern in surface corneal epithelial cells during the nighttime in Xenopus laevis, and may play a role in homeostatic surface cell desquamation by disrupting intercellular junctional proteins. The sequence of MMP secretion and activation, tight junction protein cleavage, and subsequent surface cell desquamation and renewal may be orchestrated by nocturnal circadian signals.
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Affiliation(s)
- Allan F. Wiechmann
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- * E-mail:
| | - Brian P. Ceresa
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Eric W. Howard
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
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Molecular and structural transmembrane determinants critical for embedding claudin-5 into tight junctions reveal a distinct four-helix bundle arrangement. Biochem J 2014; 464:49-60. [DOI: 10.1042/bj20140431] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A model of the transmembrane arrangement of claudin-5 as a prototype claudin is provided. Claudin subtype-specific molecular interfaces formed by conserved coiled-coil motifs and non-conserved residues in distinct positions of TM3/TM4 and ECL2 of claudin-5 essentially contribute to claudin-5 assembly into tight junctions.
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Ivanov AI. Tissue Barriers: Introducing an exciting new journal. Temperature (Austin) 2014; 1:151-3. [PMID: 27626042 PMCID: PMC5008708 DOI: 10.4161/23328940.2014.978716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 10/16/2014] [Accepted: 10/16/2014] [Indexed: 11/19/2022] Open
Abstract
This Editorial is written to introduce Tissue Barriers, a new Taylor & Francis journal, to the readers of Temperature. It describes the role of temperature in the regulation of different tissue barriers under normal and disease conditions. It also highlights the most interesting articles published in the first volume of Tissue Barriers.
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Affiliation(s)
- Andrei I Ivanov
- Department of Human and Molecular Genetics; Virginia Institute of Molecular Medicine; VCU Massey Cancer Center; Virginia Commonwealth University ; Richmond, VA USA
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Rossa J, Ploeger C, Vorreiter F, Saleh T, Protze J, Günzel D, Wolburg H, Krause G, Piontek J. Claudin-3 and claudin-5 protein folding and assembly into the tight junction are controlled by non-conserved residues in the transmembrane 3 (TM3) and extracellular loop 2 (ECL2) segments. J Biol Chem 2014; 289:7641-53. [PMID: 24478310 PMCID: PMC3953276 DOI: 10.1074/jbc.m113.531012] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 01/28/2014] [Indexed: 11/06/2022] Open
Abstract
The mechanism of tight junction (TJ) assembly and the structure of claudins (Cldn) that form the TJ strands are unclear. This limits the molecular understanding of paracellular barriers and strategies for drug delivery across tissue barriers. Cldn3 and Cldn5 are both common in the blood-brain barrier but form TJ strands with different ultrastructures. To identify the molecular determinants of folding and assembly of these classic claudins, Cldn3/Cldn5 chimeric mutants were generated and analyzed by cellular reconstitution of TJ strands, live cell confocal imaging, and freeze-fracture electron microscopy. A comprehensive screening was performed on the basis of the rescue of mutants deficient for strand formation. Cldn3/Cldn5 residues in transmembrane segment 3, TM3 (Ala-127/Cys-128, Ser-136/Cys-137, Ser-138/Phe-139), and the transition of TM3 to extracellular loop 2, ECL2 (Thr-141/Ile-142) and ECL2 (Asn-148/Asp-149, Leu-150/Thr-151, Arg-157/Tyr-158), were identified to be involved in claudin folding and/or assembly. Blue native PAGE and FRET assays revealed 1% n-dodecyl β-d-maltoside-resistant cis-dimerization for Cldn5 but not for Cldn3. This homophilic interaction was found to be stabilized by residues in TM3. The resulting subtype-specific cis-dimer is suggested to be a subunit of polymeric TJ strands and contributes to the specific ultrastructure of the TJ detected by freeze-fracture electron microscopy. In particular, the Cldn5-like exoplasmic face-associated and particle-type strands were found to be related to cis-dimerization. These results provide new insight into the mechanisms of paracellular barrier formation by demonstrating that defined non-conserved residues in TM3 and ECL2 of classic claudins contribute to the formation of TJ strands with differing ultrastructures.
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Affiliation(s)
- Jan Rossa
- From the Leibniz-Institut für Molekulare Pharmakologie, Department of Structural Biology, 13125 Berlin, Germany
| | - Carolin Ploeger
- From the Leibniz-Institut für Molekulare Pharmakologie, Department of Structural Biology, 13125 Berlin, Germany
| | - Fränze Vorreiter
- From the Leibniz-Institut für Molekulare Pharmakologie, Department of Structural Biology, 13125 Berlin, Germany
| | - Tarek Saleh
- From the Leibniz-Institut für Molekulare Pharmakologie, Department of Structural Biology, 13125 Berlin, Germany
- the Institute of Clinical Physiology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany, and
| | - Jonas Protze
- From the Leibniz-Institut für Molekulare Pharmakologie, Department of Structural Biology, 13125 Berlin, Germany
| | - Dorothee Günzel
- the Institute of Clinical Physiology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany, and
| | - Hartwig Wolburg
- the Institute of Pathology and Neuropathology, Department of General Pathology, University of Tübingen, 72076 Tübingen, Germany
| | - Gerd Krause
- From the Leibniz-Institut für Molekulare Pharmakologie, Department of Structural Biology, 13125 Berlin, Germany
| | - Jörg Piontek
- From the Leibniz-Institut für Molekulare Pharmakologie, Department of Structural Biology, 13125 Berlin, Germany
- the Institute of Clinical Physiology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany, and
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Abstract
Since the discovery of Claudins more than a decade ago, much has been learned about their structure-function relationships. Claudins are tetraspan membrane proteins responsible for the formation of tight junctions. In this capacity, Claudins form a tissue-specific selective permeability barrier that is critical for the function of the tissue. Claudins are developmentally regulated and expressed in a tissue- and cell-specific manner; chronic changes in their expression are associated with various disease states. The studies that have been put together in this Special Issue provide updates on both current knowledge as well as some of the unanswered questions and challenges in the field.
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Affiliation(s)
- Kursad Turksen
- Regenerative Medicine Program; Sprott Centre for Stem Cell Research; Ottawa Hospital Research Institute; Ottawa, ON Canada
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