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Dithmer S, Blasig IE, Fraser PA, Qin Z, Haseloff RF. The Basic Requirement of Tight Junction Proteins in Blood-Brain Barrier Function and Their Role in Pathologies. Int J Mol Sci 2024; 25:5601. [PMID: 38891789 PMCID: PMC11172262 DOI: 10.3390/ijms25115601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 03/10/2024] [Accepted: 03/28/2024] [Indexed: 06/21/2024] Open
Abstract
This review addresses the role of tight junction proteins at the blood-brain barrier (BBB). Their expression is described, and their role in physiological and pathological processes at the BBB is discussed. Based on this, new approaches are depicted for paracellular drug delivery and diagnostics in the treatment of cerebral diseases. Recent data provide convincing evidence that, in addition to its impairment in the course of diseases, the BBB could be involved in the aetiology of CNS disorders. Further progress will be expected based on new insights in tight junction protein structure and in their involvement in signalling pathways.
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Affiliation(s)
- Sophie Dithmer
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125 Berlin, Germany (I.E.B.)
| | - Ingolf E. Blasig
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125 Berlin, Germany (I.E.B.)
| | | | - Zhihai Qin
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100049, China
| | - Reiner F. Haseloff
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125 Berlin, Germany (I.E.B.)
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2
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Alluri H, Peddaboina CS, Tharakan B. Evaluation of Tight Junction Integrity in Brain Endothelial Cells Using Confocal Microscopy. Methods Mol Biol 2024; 2711:257-262. [PMID: 37776464 DOI: 10.1007/978-1-0716-3429-5_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/02/2023]
Abstract
The blood-brain barrier (BBB) is a highly complex and dynamic microvascular barrier that protects the brain parenchyma from the entry of pathogens, toxins, and other macromolecules and is a critical structure that helps to maintain brain homeostasis. The BBB is formed mainly by brain capillary endothelial cells and perivascular astrocytes and pericytes. One of the primary properties of the BBB is a tight regulation of paracellular permeability due to the presence of tight junctional complexes (also, adherens and gap junctions) between the neighboring microvascular endothelial cells. Alterations in the assembly of the tight junctions impair BBB properties, particularly influenced barrier integrity and permeability. The tight junctions of the BBB are mainly composed of proteins including claudins, occludin, and zonula occludens-1 (ZO-1). Zonula occludens-1 binds to the actin cytoskeleton, and its localization provides valuable information on the status of BBB integrity and permeability. Immunofluorescence localization of ZO-1 and/or other tight junction proteins is a reliable indicator of barrier integrity and permeability in microvascular endothelial cells. In microvascular endothelial cells, f-actin stress fiber formation significantly influences the rate and size of the inter-endothelial cell gap that form as cells retract from their borders. Rhodamine phalloidin is a popular conjugate used as a fluorescent label for f-actin. Herein, we describe the procedures for ZO-1 immunofluorescence and f-actin labeling followed by confocal microscopic imaging to determine barrier integrity and tight junction organization in brain microvascular endothelial cells in vitro.
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Affiliation(s)
| | | | - Binu Tharakan
- Department of Surgery, Morehouse School of Medicine, Atlanta, GA, USA.
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3
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Höfling C, Roßner S, Flachmeyer B, Krueger M, Härtig W, Michalski D. Tricellulin, α-Catenin and Microfibrillar-Associated Protein 5 Exhibit Concomitantly Altered Immunosignals along with Vascular, Extracellular and Cytoskeletal Elements after Experimental Focal Cerebral Ischemia. Int J Mol Sci 2023; 24:11893. [PMID: 37569268 PMCID: PMC10418498 DOI: 10.3390/ijms241511893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/08/2023] [Accepted: 07/21/2023] [Indexed: 08/13/2023] Open
Abstract
Along with initiatives to understand the pathophysiology of stroke in detail and to identify neuroprotective targets, cell-stabilizing elements have gained increasing attention. Although cell culture experiments have indicated that tricellulin, α-catenin and microfibrillar-associated protein 5 (MFAP5) contribute to cellular integrity, these elements have not yet been investigated in the ischemic brain. Applying immunofluorescence labeling, this study explored tricellulin, MFAP5 and α-catenin in non-ischemic and ischemic brain areas of mice (24, 4 h of ischemia) and rats (4 h of ischemia), along with collagen IV and fibronectin as vascular and extracellular matrix constituents and microtubule-associated protein 2 (MAP2) and neurofilament light chain (NF-L) as cytoskeletal elements. Immunosignals of tricellulin and notably MFAP5 partially appeared in a fiber-like pattern, and α-catenin appeared more in a dotted pattern. Regional associations with vascular and extracellular constituents were found for tricellulin and α-catenin, particularly in ischemic areas. Due to ischemia, signals of tricellulin, MFAP5 and α-catenin decreased concomitantly with MAP2 and NF-L, whereby MFAP5 provided the most sensitive reaction. For the first time, this study demonstrated ischemia-related alterations in tricellulin, MFAP5 and α-catenin along with the vasculature, extracellular matrix and cytoskeleton. Confirmatory studies are needed, also exploring their role in cellular integrity and the potential for neuroprotective approaches in stroke.
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Affiliation(s)
- Corinna Höfling
- Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstr. 19, 04103 Leipzig, Germany; (C.H.); (S.R.); (W.H.)
| | - Steffen Roßner
- Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstr. 19, 04103 Leipzig, Germany; (C.H.); (S.R.); (W.H.)
| | - Bianca Flachmeyer
- Institute of Anatomy, University of Leipzig, Liebigstr. 13, 04103 Leipzig, Germany; (B.F.); (M.K.)
| | - Martin Krueger
- Institute of Anatomy, University of Leipzig, Liebigstr. 13, 04103 Leipzig, Germany; (B.F.); (M.K.)
| | - Wolfgang Härtig
- Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstr. 19, 04103 Leipzig, Germany; (C.H.); (S.R.); (W.H.)
| | - Dominik Michalski
- Department of Neurology, University of Leipzig, Liebigstr. 20, 04103 Leipzig, Germany
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4
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Motta CS, Torices S, da Rosa BG, Marcos AC, Alvarez-Rosa L, Siqueira M, Moreno-Rodriguez T, Matos ADR, Caetano BC, Martins JSCDC, Gladulich L, Loiola E, Bagshaw ORM, Stuart JA, Siqueira MM, Stipursky J, Toborek M, Adesse D. Human Brain Microvascular Endothelial Cells Exposure to SARS-CoV-2 Leads to Inflammatory Activation through NF-κB Non-Canonical Pathway and Mitochondrial Remodeling. Viruses 2023; 15:745. [PMID: 36992454 PMCID: PMC10056985 DOI: 10.3390/v15030745] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 02/10/2023] [Accepted: 03/03/2023] [Indexed: 03/15/2023] Open
Abstract
Neurological effects of COVID-19 and long-COVID-19, as well as neuroinvasion by SARS-CoV-2, still pose several questions and are of both clinical and scientific relevance. We described the cellular and molecular effects of the human brain microvascular endothelial cells (HBMECs) in vitro exposure by SARS-CoV-2 to understand the underlying mechanisms of viral transmigration through the blood-brain barrier. Despite the low to non-productive viral replication, SARS-CoV-2-exposed cultures displayed increased immunoreactivity for cleaved caspase-3, an indicator of apoptotic cell death, tight junction protein expression, and immunolocalization. Transcriptomic profiling of SARS-CoV-2-challenged cultures revealed endothelial activation via NF-κB non-canonical pathway, including RELB overexpression and mitochondrial dysfunction. Additionally, SARS-CoV-2 led to altered secretion of key angiogenic factors and to significant changes in mitochondrial dynamics, with increased mitofusin-2 expression and increased mitochondrial networks. Endothelial activation and remodeling can further contribute to neuroinflammatory processes and lead to further BBB permeability in COVID-19.
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Affiliation(s)
- Carolline Soares Motta
- Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, Brazil
| | - Silvia Torices
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Barbara Gomes da Rosa
- Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, Brazil
| | - Anne Caroline Marcos
- Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, Brazil
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Liandra Alvarez-Rosa
- Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, Brazil
- Laboratório Compartilhado, Instituto de Ciências Biomédicas, UFRJ, Rio de Janeiro 05508-000, Brazil
| | - Michele Siqueira
- Laboratório Compartilhado, Instituto de Ciências Biomédicas, UFRJ, Rio de Janeiro 05508-000, Brazil
| | - Thaidy Moreno-Rodriguez
- Urology Department, University of California San Francisco, San Francisco, CA 94143, USA
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Aline da Rocha Matos
- Laboratório de Vírus Respiratórios, Exantemáticos, Enterovírus e Emergências Virais (LVRE), Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, Brazil
| | - Braulia Costa Caetano
- Laboratório de Vírus Respiratórios, Exantemáticos, Enterovírus e Emergências Virais (LVRE), Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, Brazil
| | - Jessica Santa Cruz de Carvalho Martins
- Laboratório de Vírus Respiratórios, Exantemáticos, Enterovírus e Emergências Virais (LVRE), Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, Brazil
| | - Luis Gladulich
- Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, Brazil
| | - Erick Loiola
- Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, Brazil
| | - Olivia R. M. Bagshaw
- Faculty of Mathematics & Science, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Jeffrey A. Stuart
- Faculty of Mathematics & Science, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Marilda M. Siqueira
- Laboratório de Vírus Respiratórios, Exantemáticos, Enterovírus e Emergências Virais (LVRE), Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, Brazil
| | - Joice Stipursky
- Laboratório Compartilhado, Instituto de Ciências Biomédicas, UFRJ, Rio de Janeiro 05508-000, Brazil
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Daniel Adesse
- Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-360, Brazil
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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Castro Dias M, Odriozola Quesada A, Soldati S, Bösch F, Gruber I, Hildbrand T, Sönmez D, Khire T, Witz G, McGrath JL, Piontek J, Kondoh M, Deutsch U, Zuber B, Engelhardt B. Brain endothelial tricellular junctions as novel sites for T cell diapedesis across the blood-brain barrier. J Cell Sci 2021; 134:237782. [PMID: 33912914 PMCID: PMC8121105 DOI: 10.1242/jcs.253880] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 03/12/2021] [Indexed: 12/14/2022] Open
Abstract
The migration of activated T cells across the blood–brain barrier (BBB) is a critical step in central nervous system (CNS) immune surveillance and inflammation. Whereas T cell diapedesis across the intact BBB seems to occur preferentially through the BBB cellular junctions, impaired BBB integrity during neuroinflammation is accompanied by increased transcellular T cell diapedesis. The underlying mechanisms directing T cells to paracellular versus transcellular sites of diapedesis across the BBB remain to be explored. By combining in vitro live-cell imaging of T cell migration across primary mouse brain microvascular endothelial cells (pMBMECs) under physiological flow with serial block-face scanning electron microscopy (SBF-SEM), we have identified BBB tricellular junctions as novel sites for T cell diapedesis across the BBB. Downregulated expression of tricellular junctional proteins or protein-based targeting of their interactions in pMBMEC monolayers correlated with enhanced transcellular T cell diapedesis, and abluminal presence of chemokines increased T cell diapedesis through tricellular junctions. Our observations assign an entirely novel role to BBB tricellular junctions in regulating T cell entry into the CNS. This article has an associated First Person interview with the first author of the paper. Highlighted Article: Ultrastructural analysis of T cell migration across the blood–brain barrier (BBB) under physiological flow identifies BBB tricellular junctions as sites of T cell diapedesis.
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Affiliation(s)
| | | | - Sasha Soldati
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Fabio Bösch
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Isabelle Gruber
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | | | - Derya Sönmez
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Tejas Khire
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 270168, USA
| | - Guillaume Witz
- Microscopy Imaging Center (MIC), University of Bern, Bern CH-3012, Switzerland.,Science IT Support (ScITS), Mathematical Institute, University of Bern, Bern CH-3012, Switzerland
| | - James L McGrath
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 270168, USA
| | - Jörg Piontek
- Institute of Clinical Physiology, Charité - Universitätsmedizin Berlin, Berlin 10117, Germany
| | - Masuo Kondoh
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka 565-0871, Japan
| | - Urban Deutsch
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Benoît Zuber
- Institute of Anatomy, University of Bern, Bern CH-3012, Switzerland
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6
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Ghim M, Mohamied Y, Weinberg PD. The Role of Tricellular Junctions in the Transport of Macromolecules Across Endothelium. Cardiovasc Eng Technol 2021; 12:101-113. [PMID: 32820467 PMCID: PMC7904563 DOI: 10.1007/s13239-020-00483-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/11/2020] [Indexed: 02/07/2023]
Abstract
PURPOSE Transport of water and solutes across vascular endothelium is important in normal physiology and critical in the development of various diseases, including atherosclerosis. However, there is debate about the routes for such transport. We recently showed that an albumin-sized tracer crossed endothelium at bicellular and tricellular junctions, a tracer having the size of high density lipoprotein crossed only through tricellular junctions, and a tracer with the size of low density lipoprotein was unable to cross by either route and instead traversed the cells themselves. Here we review previous work on the structure and function of tricellular junctions. We then describe a study in which we assessed the role of such junctions in the transport of an albumin-sized tracer. METHODS We examined normal endothelial monolayers, the effect of agonists that modify their permeability, and the influence of different patterns of shear stress. RESULTS Under normal conditions, approximately 85% of transendothelial transport occurred through tricellular junctions. This fraction was unchanged when permeability was reduced by sphingosine-1-phosphate or increased by thrombin, and also did not differ between endothelium exposed to multidirectional as opposed to uniaxial shear stress despite a > 50% difference in permeability. CONCLUSION These data show that tricellular junctions dominate normal transport of this tracer and largely determine influences of agonists and shear. The effects were attributable to changes in both the number and conductivity of the junctions. Further investigation of these structures will lead to increased understanding of endothelial barrier function and may suggest new therapeutic strategies in disease.
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Affiliation(s)
- Mean Ghim
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
- School of Informatics, University of Edinburgh, Edinburgh, UK
| | - Yumnah Mohamied
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
- Department of Aeronautics, Imperial College London, London, SW7 2AZ, UK
- Section of Cardiovascular Medicine, Yale Cardiovascular Research Centre, Yale University School of Medicine, New Haven, CT, USA
| | - Peter D Weinberg
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK.
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7
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Marchetti L, Engelhardt B. Immune cell trafficking across the blood-brain barrier in the absence and presence of neuroinflammation. VASCULAR BIOLOGY 2020; 2:H1-H18. [PMID: 32923970 PMCID: PMC7439848 DOI: 10.1530/vb-19-0033] [Citation(s) in RCA: 130] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 03/20/2020] [Indexed: 12/18/2022]
Abstract
To maintain the homeostatic environment required for proper function of CNS neurons the endothelial cells of CNS microvessels tightly regulate the movement of ions and molecules between the blood and the CNS. The unique properties of these blood vascular endothelial cells are termed blood-brain barrier (BBB) and extend to regulating immune cell trafficking into the immune privileged CNS during health and disease. In general, extravasation of circulating immune cells is a multi-step process regulated by the sequential interaction of adhesion and signalling molecules between the endothelial cells and the immune cells. Accounting for the unique barrier properties of CNS microvessels, immune cell migration across the BBB is distinct and characterized by several adaptations. Here we describe the mechanisms that regulate immune cell trafficking across the BBB during immune surveillance and neuroinflammation, with a focus on the current state-of-the-art in vitro and in vivo imaging observations.
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Affiliation(s)
- Luca Marchetti
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
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8
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Min S, Cong X, Zhang Y, Xiang R, Zhou Y, Yu G, Wu L. Tricellulin Modulates Transport of Macromolecules in the Salivary Gland. J Dent Res 2019; 99:302-310. [DOI: 10.1177/0022034519896749] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Volume and composition of saliva are crucial for oral and systemic health. How substances, particularly macromolecules, are transported across the salivary gland epithelium has not been established in detail. Tricellulin is a component of tricellular tight junctions that form a central tube to serve as an important route for macromolecule transport. Whether tricellulin is expressed in the submandibular gland (SMG) and involved in salivation has been unknown. Here, by using Western blotting and immunofluorescence, tricellulin was found to be characteristically localized at tricellular contacts of human, rat, and mouse SMGs. Knockdown of tricellulin significantly increased, whereas overexpression of tricellulin decreased, paracellular permeability for 40-kDa but not for 4-kDa fluorescein isothiocyanate–dextran, while transepithelial electrical resistance was unaffected. Conversely, claudin-4 knockdown and overexpression affected transepithelial electrical resistance but not 40-kDa fluorescein isothiocyanate–dextran transport, suggesting that tricellulin regulated transport of macromolecules but not ions, which were mainly regulated by bicellular tight junctions (bTJs). Moreover, tricellulin was dynamically redistributed from tri- to bicellular membranes in cholinergically stimulated SMG tissues and cells. Immunoglobulin-like domain-containing receptor 1 (ILDR1) recruits tricellulin to tricellular contacts. The proportion of macromolecules in the saliva was increased, whereas the amount of stimulated saliva was unchanged in Ildr1-/- mice, which displayed abnormal tricellulin distribution in SMGs. Furthermore, tricellulin interacted with bTJ proteins, such as occludin, claudin-1, claudin-3, claudin-4, and ZO-1, in rat SMG epithelial polarized cell line SMG-C6. Knockdown of tricellulin decreased occludin levels. Thus, we revealed a specific expression pattern of tricellulin in SMG epithelium. Tricellulin not only functioned as a barrier for macromolecules but also modulated the connection of bTJs to the tight junction complex. Alterations in tricellulin expression and distribution could thereby change salivary composition. Our study provided novel insights on salivary gland tight junction organization and function.
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Affiliation(s)
- S.N. Min
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China
| | - X. Cong
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Y. Zhang
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - R.L. Xiang
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Y. Zhou
- Department of Clinical Laboratory, China-Japan Friendship Hospital, Beijing, China
| | - G.Y. Yu
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China
| | - L.L. Wu
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
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9
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Cong X, Kong W. Endothelial tight junctions and their regulatory signaling pathways in vascular homeostasis and disease. Cell Signal 2019; 66:109485. [PMID: 31770579 DOI: 10.1016/j.cellsig.2019.109485] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/21/2019] [Accepted: 11/21/2019] [Indexed: 12/13/2022]
Abstract
Endothelial tight junctions (TJs) regulate the transport of water, ions, and molecules through the paracellular pathway, serving as an important barrier in blood vessels and maintaining vascular homeostasis. In endothelial cells (ECs), TJs are highly dynamic structures that respond to multiple external stimuli and pathological conditions. Alterations in the expression, distribution, and structure of endothelial TJs may lead to many related vascular diseases and pathologies. In this review, we provide an overview of the assessment methods used to evaluate endothelial TJ barrier function both in vitro and in vivo and describe the composition of endothelial TJs in diverse vascular systems and ECs. More importantly, the direct phosphorylation and dephosphorylation of TJ proteins by intracellular kinases and phosphatases, as well as the signaling pathways involved in the regulation of TJs, including and the protein kinase C (PKC), PKA, PKG, Ras homolog gene family member A (RhoA), mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K)/Akt, and Wnt/β-catenin pathways, are discussed. With great advances in this area, targeting endothelial TJs may provide novel treatment for TJ-related vascular pathologies.
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Affiliation(s)
- Xin Cong
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China.
| | - Wei Kong
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China.
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10
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Castro Dias M, Mapunda JA, Vladymyrov M, Engelhardt B. Structure and Junctional Complexes of Endothelial, Epithelial and Glial Brain Barriers. Int J Mol Sci 2019; 20:E5372. [PMID: 31671721 PMCID: PMC6862204 DOI: 10.3390/ijms20215372] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 10/25/2019] [Accepted: 10/26/2019] [Indexed: 01/04/2023] Open
Abstract
The homeostasis of the central nervous system (CNS) is ensured by the endothelial, epithelial, mesothelial and glial brain barriers, which strictly control the passage of molecules, solutes and immune cells. While the endothelial blood-brain barrier (BBB) and the epithelial blood-cerebrospinal fluid barrier (BCSFB) have been extensively investigated, less is known about the epithelial and mesothelial arachnoid barrier and the glia limitans. Here, we summarize current knowledge of the cellular composition of the brain barriers with a specific focus on describing the molecular constituents of their junctional complexes. We propose that the brain barriers maintain CNS immune privilege by dividing the CNS into compartments that differ with regard to their role in immune surveillance of the CNS. We close by providing a brief overview on experimental tools allowing for reliable in vivo visualization of the brain barriers and their junctional complexes and thus the respective CNS compartments.
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Affiliation(s)
| | | | | | - Britta Engelhardt
- Theodor Kocher Institute, University of Bern, 3012 Bern, Switzerland.
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11
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Johnsen KB, Burkhart A, Thomsen LB, Andresen TL, Moos T. Targeting the transferrin receptor for brain drug delivery. Prog Neurobiol 2019; 181:101665. [DOI: 10.1016/j.pneurobio.2019.101665] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 07/10/2019] [Accepted: 07/18/2019] [Indexed: 02/07/2023]
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12
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Murata M, Osanai M, Takasawa A, Takasawa K, Aoyama T, Kawada Y, Yamamoto A, Ono Y, Hiratsuka Y, Kojima T, Sawada N. Occludin induces microvillus formation via phosphorylation of ezrin in a mouse hepatic cell line. Exp Cell Res 2018; 366:172-180. [PMID: 29555369 DOI: 10.1016/j.yexcr.2018.03.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 03/13/2018] [Accepted: 03/15/2018] [Indexed: 11/30/2022]
Abstract
Apical and basolateral cell membranes are separated by tight junctions (TJs). Microvilli are limited to the apical cell membrane. TJs and microvilli are the landmarks for epithelial cell polarity. However, the direct relationship between TJ proteins (TJPs) and the components of microvilli remains unclear. In this study, we investigated whether occludin, which is considered to be a functional TJP, is involved in microvillus formation. In occludin knockout mouse hepatic cells (OcKO cells), the microvillus density was less than that in wild-type (WT) cells and the length of microvilli was short. Immunoreactivity of ezrin was decreased in OcKO cells compared with that in WT cells. Although there was no change in the expression level of ezrin, phosphorylation of ezrin was decreased in OcKO cells. The microvillus density and the length of microvilli were increased in OcKO cells by transfection of full-length mouse occludin and COOH-terminal domains of occludin. These results suggested that occludin induced microvillus formation via phosphorylation of ezrin and that the COOH-terminal domain of occludin, which is localized in non-TJ areas, might be able to induce microvilli formation. Our results provide new insights into the function of occludin.
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Affiliation(s)
- Masaki Murata
- Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan.
| | - Makoto Osanai
- Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan
| | - Akira Takasawa
- Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan
| | - Kumi Takasawa
- Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan
| | - Tomoyuki Aoyama
- Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan
| | - Yuka Kawada
- Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan
| | - Akihiro Yamamoto
- Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan
| | - Yusuke Ono
- Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan
| | - Yutaro Hiratsuka
- Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan
| | - Takashi Kojima
- Department of Cell Science, Research Institute of Frontier Medicine, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan
| | - Norimasa Sawada
- Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan
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13
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Higashi T, Miller AL. Tricellular junctions: how to build junctions at the TRICkiest points of epithelial cells. Mol Biol Cell 2017; 28:2023-2034. [PMID: 28705832 PMCID: PMC5509417 DOI: 10.1091/mbc.e16-10-0697] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/05/2017] [Accepted: 05/10/2017] [Indexed: 01/07/2023] Open
Abstract
Tricellular contacts are the places where three cells meet. In vertebrate epithelial cells, specialized structures called tricellular tight junctions (tTJs) and tricellular adherens junctions (tAJs) have been identified. tTJs are important for the maintenance of barrier function, and disruption of tTJ proteins contributes to familial deafness. tAJs have recently been attracting the attention of mechanobiologists because these sites are hot spots of epithelial tension. Although the molecular components, regulation, and function of tTJs and tAJs, as well as of invertebrate tricellular junctions, are beginning to be characterized, many questions remain. Here we broadly cover what is known about tricellular junctions, propose a new model for tension transmission at tAJs, and discuss key open questions.
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Affiliation(s)
- Tomohito Higashi
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Ann L Miller
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
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14
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Ono Y, Hiratsuka Y, Murata M, Takasawa A, Fukuda R, Nojima M, Tanaka S, Osanai M, Hirata K, Sawada N. Claudins-4 and -7 might be valuable markers to distinguish hepatocellular carcinoma from cholangiocarcinoma. Virchows Arch 2016; 469:417-26. [PMID: 27444172 DOI: 10.1007/s00428-016-1984-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 04/07/2016] [Accepted: 06/30/2016] [Indexed: 12/13/2022]
Abstract
The claudin family members are the functional components of tight junctions. Expression and localization of claudins vary among organs and tumor types. In this study, we examined expression and localization of tight junction proteins (TJP) in human liver tumors, to estimate their usefulness as differential diagnostic markers. The materials used for immunohistochemical analysis were 47 liver tumor specimens including 29 cases of hepatocellular carcinoma (HCC), 15 cases of cholangiocarcinoma (CC), 3 cases of combined HCC and CC (CHC), and 3 cases of cholangiolocellular carcinoma (CoCC). Samples were examined using semiquantitative and statistical analysis of immunoreactivity. In HCC, claudin-1, occludin, tricellulin, and JAM-A were expressed on the cell membrane as well as in hepatocytes. In CC, claudins-1, -4, and -7, tricellulin, and JAM-A were expressed on the cell membrane and occludin was predominantly expressed in the apicalmost areas of the cell membrane. Significant differences in the immunohistochemical scores of claudin-4 and claudin-7 were observed when comparing HCC and CC. CHC was positive for all of the TJPs examined in this study. The expression pattern of CoCC was found to be similar to that of CC. There were differences in the distribution of intensity scores of claudins-4 and -7 and occludin between CoCC and HCC. In addition, CHC was positive for Glypican-3 and CK-19. CoCC was positive for only CK-19. The results suggest that claudins-4 and -7 might be valuable markers for distinguishing HCC and CC and that CoCC might arise from hepatic ductal cells.
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Affiliation(s)
- Yusuke Ono
- Department of Pathology, Sapporo Medical University School of Medicine, S1. W17, Sapporo, 060-8556, Japan
| | - Yutaro Hiratsuka
- Department of Pathology, Sapporo Medical University School of Medicine, S1. W17, Sapporo, 060-8556, Japan
| | - Masaki Murata
- Department of Pathology, Sapporo Medical University School of Medicine, S1. W17, Sapporo, 060-8556, Japan.
| | - Akira Takasawa
- Department of Pathology, Sapporo Medical University School of Medicine, S1. W17, Sapporo, 060-8556, Japan
| | - Rieko Fukuda
- Department of Pathology, Sapporo Medical University School of Medicine, S1. W17, Sapporo, 060-8556, Japan
| | - Masanori Nojima
- Division of Advanced Medicine Promotion, The Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Satoshi Tanaka
- Department of Pathology, Sapporo Medical University School of Medicine, S1. W17, Sapporo, 060-8556, Japan
| | - Makoto Osanai
- Department of Pathology, Sapporo Medical University School of Medicine, S1. W17, Sapporo, 060-8556, Japan
| | - Koichi Hirata
- Department of Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Norimasa Sawada
- Department of Pathology, Sapporo Medical University School of Medicine, S1. W17, Sapporo, 060-8556, Japan
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15
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Cellular response of the blood-brain barrier to injury: Potential biomarkers and therapeutic targets for brain regeneration. Neurobiol Dis 2016; 91:262-73. [DOI: 10.1016/j.nbd.2016.03.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/09/2016] [Accepted: 03/16/2016] [Indexed: 02/07/2023] Open
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16
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Cording J, Günther R, Vigolo E, Tscheik C, Winkler L, Schlattner I, Lorenz D, Haseloff RF, Schmidt-Ott KM, Wolburg H, Blasig IE. Redox Regulation of Cell Contacts by Tricellulin and Occludin: Redox-Sensitive Cysteine Sites in Tricellulin Regulate Both Tri- and Bicellular Junctions in Tissue Barriers as Shown in Hypoxia and Ischemia. Antioxid Redox Signal 2015; 23:1035-49. [PMID: 25919114 DOI: 10.1089/ars.2014.6162] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
UNLABELLED Tight junctions (TJs) seal paracellular clefts in epithelia/endothelia and form tissue barriers for proper organ function. TJ-associated marvel proteins (TAMPs; tricellulin, occludin, marvelD3) are thought to be relevant to regulation. Under normal conditions, tricellulin tightens tricellular junctions against macromolecules. Traces of tricellulin occur in bicellular junctions. AIMS As pathological disturbances have not been analyzed, the structure and function of human tricellulin, including potentially redox-sensitive Cys sites, were investigated under reducing/oxidizing conditions at 3- and 2-cell contacts. RESULTS Ischemia, hypoxia, and reductants redistributed tricellulin from 3- to 2-cell contacts. The extracellular loop 2 (ECL2; conserved Cys321, Cys335) trans-oligomerized between three opposing cells. Substitutions of these residues caused bicellular localization. Cys362 in transmembrane domain 4 contributed to bicellular heterophilic cis-interactions along the cell membrane with claudin-1 and marvelD3, while Cys395 in the cytosolic C-terminal tail promoted homophilic tricellullar cis-interactions. The Cys sites included in homo-/heterophilic bi-/tricellular cis-/trans-interactions contributed to cell barrier tightness for small/large molecules. INNOVATION Tricellulin forms TJs via trans- and cis-association in 3-cell contacts, as demonstrated electron and quantified fluorescence microscopically; it tightens 3- and 2-cell contacts. Tricellulin's ECL2 specifically seals 3-cell contacts redox dependently; a structural model is proposed. CONCLUSIONS TAMP ECL2 and claudins' ECL1 share functionally and structurally similar features involved in homo-/heterophilic tightening of cell-cell contacts. Tricellulin is a specific redox sensor and sealing element at 3-cell contacts and may compensate as a redox mediator for occludin loss at 2-cell contacts in vivo and in vitro. Molecular interaction mechanisms were proposed that contribute to tricellulin's function. In conclusion, tricellulin is a junctional redox regulator for ischemia-related alterations.
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Affiliation(s)
- Jimmi Cording
- 1 Leibniz-Institut für Molekulare Pharmakologie , Berlin, Germany
| | - Ramona Günther
- 1 Leibniz-Institut für Molekulare Pharmakologie , Berlin, Germany
| | - Emilia Vigolo
- 2 Department of Nephrology, Max Delbrueck Center for Molecular Medicine , Charite Berlin, Berlin, Germany
| | | | - Lars Winkler
- 1 Leibniz-Institut für Molekulare Pharmakologie , Berlin, Germany
| | | | - Dorothea Lorenz
- 1 Leibniz-Institut für Molekulare Pharmakologie , Berlin, Germany
| | | | - Kai M Schmidt-Ott
- 2 Department of Nephrology, Max Delbrueck Center for Molecular Medicine , Charite Berlin, Berlin, Germany
| | - Hartwig Wolburg
- 3 Department of General Pathology, Institute of Pathology and Neuropathology, Medical School, University of Tübingen , Tübingen, Germany
| | - Ingolf E Blasig
- 1 Leibniz-Institut für Molekulare Pharmakologie , Berlin, Germany
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Alluri H, Wiggins-Dohlvik K, Davis ML, Huang JH, Tharakan B. Blood-brain barrier dysfunction following traumatic brain injury. Metab Brain Dis 2015; 30:1093-104. [PMID: 25624154 DOI: 10.1007/s11011-015-9651-7] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 01/13/2015] [Indexed: 01/24/2023]
Abstract
Traumatic brain injury is a serious cause of morbidity and mortality worldwide. After traumatic brain injury, the blood-brain barrier, the protective barrier between the brain and the intravascular compartment, becomes dysfunctional, leading to leakage of proteins, fluid, and transmigration of immune cells. As this leakage has profound clinical implications, including edema formation, elevated intracranial pressure and decreased perfusion pressure, much interest has been paid to better understanding the mechanisms responsible for these events. Various molecular pathways and numerous mediators have been found to be involved in the intricate process of regulating blood-brain barrier permeability following traumatic brain injury. This review provides an update to the existing knowledge about the various pathophysiological pathways and advancements in the field of blood-brain barrier dysfunction and hyperpermeability following traumatic brain injury, including the role of various tight junction proteins involved in blood-brain barrier integrity and regulation. We also address pitfalls of existing systems and propose strategies to improve the various debilitating functional deficits caused by this progressive epidemic.
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Affiliation(s)
- Himakarnika Alluri
- Department of Surgery, Baylor Scott & White Health & Texas A&M University Health Science Center, College of Medicine, 702 S.W. H.K. Dodgen Loop, Temple, TX, 76504, USA
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18
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Bauer HC, Krizbai IA, Bauer H, Traweger A. "You Shall Not Pass"-tight junctions of the blood brain barrier. Front Neurosci 2014; 8:392. [PMID: 25520612 PMCID: PMC4253952 DOI: 10.3389/fnins.2014.00392] [Citation(s) in RCA: 165] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 11/14/2014] [Indexed: 12/31/2022] Open
Abstract
The structure and function of the barrier layers restricting the free diffusion of substances between the central nervous system (brain and spinal cord) and the systemic circulation is of great medical interest as various pathological conditions often lead to their impairment. Excessive leakage of blood-borne molecules into the parenchyma and the concomitant fluctuations in the microenvironment following a transient breakdown of the blood-brain barrier (BBB) during ischemic/hypoxic conditions or because of an autoimmune disease are detrimental to the physiological functioning of nervous tissue. On the other hand, the treatment of neurological disorders is often hampered as only minimal amounts of therapeutic agents are able to penetrate a fully functional BBB or blood cerebrospinal fluid barrier. An in-depth understanding of the molecular machinery governing the establishment and maintenance of these barriers is necessary to develop rational strategies allowing a controlled delivery of appropriate drugs to the CNS. At the basis of such tissue barriers are intimate cell-cell contacts (zonulae occludentes, tight junctions) which are present in all polarized epithelia and endothelia. By creating a paracellular diffusion constraint TJs enable the vectorial transport across cell monolayers. More recent findings indicate that functional barriers are already established during development, protecting the fetal brain. As an understanding of the biogenesis of TJs might reveal the underlying mechanisms of barrier formation during ontogenic development numerous in vitro systems have been developed to study the assembly and disassembly of TJs. In addition, monitoring the stage-specific expression of TJ-associated proteins during development has brought much insight into the “developmental tightening” of tissue barriers. Over the last two decades a detailed molecular map of transmembrane and cytoplasmic TJ-proteins has been identified. These proteins not only form a cell-cell adhesion structure, but integrate various signaling pathways, thereby directly or indirectly impacting upon processes such as cell-cell adhesion, cytoskeletal rearrangement, and transcriptional control. This review will provide a brief overview on the establishment of the BBB during embryonic development in mammals and a detailed description of the ultrastructure, biogenesis, and molecular composition of epithelial and endothelial TJs will be given.
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Affiliation(s)
- Hans-Christian Bauer
- Institute of Tendon and Bone Regeneration, Paracelsus Medical University - Spinal Cord Injury and Tissue Regeneration Center Salzburg Salzburg, Austria ; Department of Traumatology and Sports Injuries, Paracelsus Medical University Salzburg, Austria ; Austrian Cluster for Tissue Regeneration Vienna, Austria
| | - István A Krizbai
- Biological Research Centre, Institute of Biophysics, Hungarian Academy of Sciences Szeged, Hungary ; Institute of Life Sciences, Vasile Goldis Western University of Arad Arad, Romania
| | - Hannelore Bauer
- Department of Organismic Biology, University of Salzburg Salzburg, Austria
| | - Andreas Traweger
- Institute of Tendon and Bone Regeneration, Paracelsus Medical University - Spinal Cord Injury and Tissue Regeneration Center Salzburg Salzburg, Austria ; Austrian Cluster for Tissue Regeneration Vienna, Austria
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19
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Krug SM, Schulzke JD, Fromm M. Tight junction, selective permeability, and related diseases. Semin Cell Dev Biol 2014; 36:166-76. [DOI: 10.1016/j.semcdb.2014.09.002] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 08/29/2014] [Accepted: 09/04/2014] [Indexed: 02/09/2023]
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20
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Haseloff RF, Dithmer S, Winkler L, Wolburg H, Blasig IE. Transmembrane proteins of the tight junctions at the blood-brain barrier: structural and functional aspects. Semin Cell Dev Biol 2014; 38:16-25. [PMID: 25433243 DOI: 10.1016/j.semcdb.2014.11.004] [Citation(s) in RCA: 221] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 11/14/2014] [Indexed: 01/27/2023]
Abstract
The blood-brain barrier (BBB) is formed by microvascular endothelial cells sealed by tetraspanning tight junction (TJ) proteins, such as claudins and TAMPs (TJ-associated marvel proteins, occludin and tricellulin). Claudins are the major components of the TJs. At the BBB, claudin-5 dominates the TJs by preventing the paracellular permeation of small molecules. On the other hand, TAMPs regulate the structure and function of the TJs; tricellulin may tighten the barrier for large molecules. This review aims at integrating and summarizing the most relevant and recent work on how the BBB is influenced by claudin-1, -3, -5, -12 and the TAMPs occludin and tricellulin, all of which are four-transmembrane TJ proteins. The exact functions of claudin-1, -3, -12 and TAMPs at this barrier still need to be elucidated.
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Affiliation(s)
- Reiner F Haseloff
- Leibniz Institute for Molecular Pharmacology, Robert Roessle-Str. 10, 13125 Berlin, Germany
| | - Sophie Dithmer
- Leibniz Institute for Molecular Pharmacology, Robert Roessle-Str. 10, 13125 Berlin, Germany
| | - Lars Winkler
- Leibniz Institute for Molecular Pharmacology, Robert Roessle-Str. 10, 13125 Berlin, Germany
| | - Hartwig Wolburg
- Leibniz Institute for Molecular Pharmacology, Robert Roessle-Str. 10, 13125 Berlin, Germany
| | - Ingolf E Blasig
- Leibniz Institute for Molecular Pharmacology, Robert Roessle-Str. 10, 13125 Berlin, Germany.
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21
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Schlachter K, Gyugos M, Halász J, Lendvai G, Baghy K, Garami M, Gyöngyösi B, Schaff Z, Kiss A. High tricellulin expression is associated with better survival in human hepatoblastoma. Histopathology 2014; 65:631-41. [PMID: 24735023 DOI: 10.1111/his.12436] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 04/11/2014] [Indexed: 12/21/2022]
Abstract
AIMS The more differentiated fetal component of hepatoblastoma (HB) is characterized by increased expression of tight junction (TJ) proteins claudin-1 and -2 when compared with embryonal component. Expression patterns of the recently identified TJ protein tricellulin and the epigenetic regulator enzyme EZH2 were investigated in epithelial subtypes of HB and related to survival. METHODS AND RESULTS Twenty-one cases of epithelial HBs subtyped as pure fetal (n = 12) and embryonal/fetal (n = 9), along with 16 non-tumorous samples from surrounding liver, were analysed by immunohistochemistry for tricellulin, β-catenin and EZH2 expression. No significant differences were revealed in overall survival between fetal and embryonal/fetal types of HBs. The fetal component, however, showed considerably increased tricellulin expression while the embryonal component displayed significantly increased nuclear EZH2 positivity, in comparison to other epithelial subtypes and non-tumorous surrounding hepatocytes. Strong nuclear β-catenin staining was notably more frequent in embryonal than in fetal types. High tricellulin expression was associated with significantly increased overall survival (P = 0.03), while elevated EZH2 expression was linked to the presence of distant metastases (P = 0.013). CONCLUSIONS Our data indicate that patients with treated HBs showing high expression of tricellulin have significantly better overall survival, independent of histological subtype. Increased nuclear expression of EZH2 was associated with the presence of distant metastases.
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22
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Furuse M, Izumi Y, Oda Y, Higashi T, Iwamoto N. Molecular organization of tricellular tight junctions. Tissue Barriers 2014; 2:e28960. [PMID: 25097825 PMCID: PMC4117683 DOI: 10.4161/tisb.28960] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 04/19/2014] [Accepted: 04/21/2014] [Indexed: 01/22/2023] Open
Abstract
When the apicolateral border of epithelial cells is compared with a polygon, its sides correspond to the apical junctional complex, where cell adhesion molecules assemble from the plasma membranes of two adjacent cells. On the other hand, its vertices correspond to tricellular contacts, where the corners of three cells meet. Vertebrate tricellular contacts have specialized structures of tight junctions, termed tricellular tight junctions (tTJs). tTJs were identified by electron microscopic observations more than 40 years ago, but have been largely forgotten in epithelial cell biology since then. The identification of tricellulin and angulin family proteins as tTJ-associated membrane proteins has enabled us to study tTJs in terms of not only the paracellular barrier function but also unknown characteristics of epithelial cell corners via molecular biological approaches.
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Affiliation(s)
- Mikio Furuse
- Division of Cell Biology; Department of Physiology and Cell Biology; Kobe University Graduate School of Medicine; Kobe, Japan ; Division of Cerebral Structure; National Institute for Physiological Sciences; Okazaki, Aichi Japan
| | - Yasushi Izumi
- Division of Cell Biology; Department of Physiology and Cell Biology; Kobe University Graduate School of Medicine; Kobe, Japan
| | - Yukako Oda
- Division of Cell Biology; Department of Physiology and Cell Biology; Kobe University Graduate School of Medicine; Kobe, Japan
| | - Tomohito Higashi
- Division of Cell Biology; Department of Physiology and Cell Biology; Kobe University Graduate School of Medicine; Kobe, Japan
| | - Noriko Iwamoto
- Division of Cell Biology; Department of Physiology and Cell Biology; Kobe University Graduate School of Medicine; Kobe, Japan
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23
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Wilhelm I, Krizbai IA. In vitro models of the blood-brain barrier for the study of drug delivery to the brain. Mol Pharm 2014; 11:1949-63. [PMID: 24641309 DOI: 10.1021/mp500046f] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The most important obstacle to the drug delivery into the brain is the presence of the blood-brain barrier, which limits the traffic of substances between the blood and the nervous tissue. Therefore, adequate in vitro models need to be developed in order to characterize the penetration properties of drug candidates into the central nervous system. This review article summarizes the presently used and the most promising in vitro BBB models based on the culture of brain endothelial cells. Robust models can be obtained using primary porcine brain endothelial cells and rodent coculture models, which have low paracellular permeability and express functional efflux transporters, showing good correlation of drug penetration data with in vivo results. Models mimicking the in vivo anatomophysiological complexity of the BBB are also available, including triple coculture (culture of brain endothelial cells in the presence of pericytes and astrocytes), dynamic, and microfluidic models; however, these are not suitable for rapid, high throughput studies. Potent human cell lines would be needed for easily available and reproducible models which avoid interspecies differences.
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Affiliation(s)
- Imola Wilhelm
- Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences , Temesvári krt. 62, 6726 Szeged, Hungary
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24
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Iwamoto N, Higashi T, Furuse M. Localization of Angulin-1/LSR and Tricellulin at Tricellular Contacts of Brain and Retinal Endothelial Cells in vivo. Cell Struct Funct 2014; 39:1-8. [DOI: 10.1247/csf.13015] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Noriko Iwamoto
- Division of Cell Biology, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine
| | - Tomohito Higashi
- Division of Cell Biology, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine
| | - Mikio Furuse
- Division of Cell Biology, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine
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