1
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Xu ZY, Fu SX, Zhao HC, Wang YM, Liu Y, Ma JY, Yu Y, Zhang JL, Han ZP, Zheng MX. Dynamic changes in key factors of the blood-brain barrier in early diabetic mice. J Neuropathol Exp Neurol 2024; 83:763-771. [PMID: 38874450 DOI: 10.1093/jnen/nlae056] [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: 06/15/2024] Open
Abstract
Chronic hyperglycemia can result in damage to the hippocampus and dysfunction of the blood-brain barrier (BBB), potentially leading to neurological disorders. This study examined the histological structure of the hippocampus and the expression of critical genes associated with the BBB at 2 early stage time points in a streptozotocin-induced diabetes mellitus (DM) mouse model. Routine histology revealed vascular congestion and dilation of Virchow-Robin spaces in the hippocampal CA1 region of the DM group. Neuronal alterations included rounding and swelling and reduction in Nissl bodies and increased apoptosis. Compared to the control group, TJP1 mRNA expression in the DM group was significantly lower (P < .05 or P < .01), while mRNA levels of JAM3, TJP3, CLDN5, CLDN3, and OCLN initially increased and then decreased. At 7, 14, and 21 days, mRNA levels of the receptor for advanced glycation end products (AGER) were greater in the DM group than in the control group (P < .05 or P < .01). These findings indicate that early-stage diabetes may cause structural and functional impairments in hippocampal CA1 in mice. These abnormalities may parallel alterations in the expression of key BBB tight junction molecules and elevated AGER expression in early DM patients.
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Affiliation(s)
- Zhi-Yong Xu
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Shu-Xian Fu
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Hui-Chao Zhao
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Yin-Min Wang
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Yan Liu
- The 83rd Army Group Hospital of the Chinese People's Liberation Army, Xinxiang, China
| | - Jin-You Ma
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Yan Yu
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Jia-Le Zhang
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Zhan-Peng Han
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Ming-Xue Zheng
- College of Veterinary Medicine, Shanxi Agricultural University, Taigu, China
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2
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Marsch P, Rajagopal N, Nangia S. Biophysics of claudin proteins in tight junction architecture: Three decades of progress. Biophys J 2024; 123:2363-2378. [PMID: 38859584 PMCID: PMC11365114 DOI: 10.1016/j.bpj.2024.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 05/19/2024] [Accepted: 06/07/2024] [Indexed: 06/12/2024] Open
Abstract
Tight junctions are cell-cell adhesion complexes that act as gatekeepers of the paracellular space. Formed by several transmembrane proteins, the claudin family performs the primary gate-keeping function. The claudin proteins form charge and size-selective diffusion barriers to maintain homeostasis across endothelial and epithelial tissue. Of the 27 known claudins in mammals, some are known to seal the paracellular space, while others provide selective permeability. The differences in permeability arise due to the varying expression levels of claudins in each tissue. The tight junctions are observed as strands in freeze-fracture electron monographs; however, at the molecular level, tight junction strands form when multiple claudin proteins assemble laterally (cis assembly) within a cell and head-on (trans assembly) with claudins of the adjacent cell in a zipper-like architecture, closing the gap between the neighboring cells. The disruption of tight junctions caused by changing claudin expression levels or mutations can lead to diseases. Therefore, knowledge of the molecular architecture of the tight junctions and how that is tied to tissue-specific function is critical for fighting diseases. Here, we review the current understanding of the tight junctions accrued over the last three decades from experimental and computational biophysics perspectives.
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Affiliation(s)
- Patrick Marsch
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York
| | - Nandhini Rajagopal
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York
| | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York.
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3
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van der Veen RE, Piontek J, Bieck M, Saiti A, Gonschior H, Lehmann M. Claudin-4 polymerizes after a small extracellular claudin-3-like substitution. J Biol Chem 2024:107693. [PMID: 39159821 DOI: 10.1016/j.jbc.2024.107693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/14/2024] [Accepted: 08/09/2024] [Indexed: 08/21/2024] Open
Abstract
Tight junctions play a pivotal role in the functional integrity of the human body by forming barriers that compartmentalize tissues and protect the body from external threats. Essential components of tight junctions are the transmembrane claudin proteins, which can polymerize into tight junction strands and meshworks. This study delves into the structural determinants of claudin polymerization, utilizing the close homology yet strong difference in polymerization capacity between claudin-3 and claudin-4. Through a combination of sequence alignment and structural modeling, critical residues in the second extracellular segment are pinpointed. Molecular dynamics simulations provide insights into the interactions of and the conformational changes induced by the identified extracellular segment 2 residues. Live-STED imaging demonstrates that introduction of these residues from claudin-3 into claudin-4 significantly enhances polymerization in non-epithelial cells. In tight junction-deficient epithelial cells, mutated claudin-4 not only influences tight junction morphology but also partially restores barrier function. Understanding the structural basis of claudin polymerization is crucial, as it offers insights into the dynamic nature of tight junctions. This knowledge could be applied to targeted therapeutic interventions, offering insight to repair or prevent barrier defects associated with pathological conditions, or introduce temporary barrier openings during drug delivery.
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Affiliation(s)
| | - Jörg Piontek
- Clinical Physiology/Nutritional Medicine, Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Hindenburgdamm 30, 12203 Berlin, Germany
| | - Marie Bieck
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Arbesa Saiti
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Hannes Gonschior
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Martin Lehmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany.
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4
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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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5
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Vázquez-Liébanas E, Mocci G, Li W, Laviña B, Reddy A, O'Connor C, Hudson N, Elbeck Z, Nikoloudis I, Gaengel K, Vanlandewijck M, Campbell M, Betsholtz C, Mäe MA. Mosaic deletion of claudin-5 reveals rapid non-cell-autonomous consequences of blood-brain barrier leakage. Cell Rep 2024; 43:113911. [PMID: 38446668 DOI: 10.1016/j.celrep.2024.113911] [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: 07/14/2023] [Revised: 12/19/2023] [Accepted: 02/16/2024] [Indexed: 03/08/2024] Open
Abstract
Claudin-5 (CLDN5) is an endothelial tight junction protein essential for blood-brain barrier (BBB) formation. Abnormal CLDN5 expression is common in brain disease, and knockdown of Cldn5 at the BBB has been proposed to facilitate drug delivery to the brain. To study the consequences of CLDN5 loss in the mature brain, we induced mosaic endothelial-specific Cldn5 gene ablation in adult mice (Cldn5iECKO). These mice displayed increased BBB permeability to tracers up to 10 kDa in size from 6 days post induction (dpi) and ensuing lethality from 10 dpi. Single-cell RNA sequencing at 11 dpi revealed profound transcriptomic differences in brain endothelial cells regardless of their Cldn5 status in mosaic mice, suggesting major non-cell-autonomous responses. Reactive microglia and astrocytes suggested rapid cellular responses to BBB leakage. Our study demonstrates a critical role for CLDN5 in the adult BBB and provides molecular insight into the consequences and risks associated with CLDN5 inhibition.
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Affiliation(s)
- Elisa Vázquez-Liébanas
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, 751 85 Uppsala, Sweden
| | - Giuseppe Mocci
- Single Cell Core Facility of Flemingsberg Campus (SICOF), Karolinska Institute, 14157 Huddinge, Sweden
| | - Weihan Li
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, 751 85 Uppsala, Sweden
| | - Bàrbara Laviña
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, 751 85 Uppsala, Sweden
| | - Avril Reddy
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Claire O'Connor
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Natalie Hudson
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Zaher Elbeck
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, 751 85 Uppsala, Sweden
| | - Ioannis Nikoloudis
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, 751 85 Uppsala, Sweden
| | - Konstantin Gaengel
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, 751 85 Uppsala, Sweden
| | - Michael Vanlandewijck
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, 751 85 Uppsala, Sweden; Single Cell Core Facility of Flemingsberg Campus (SICOF), Karolinska Institute, 14157 Huddinge, Sweden; Department of Medicine, Karolinska Institute, 14157 Huddinge, Sweden
| | - Matthew Campbell
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Christer Betsholtz
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, 751 85 Uppsala, Sweden; Department of Medicine, Karolinska Institute, 14157 Huddinge, Sweden
| | - Maarja Andaloussi Mäe
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, 751 85 Uppsala, Sweden.
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6
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Zhang S, Meng R, Jiang M, Qing H, Ni J. Emerging Roles of Microglia in Blood-Brain Barrier Integrity in Aging and Neurodegeneration. Curr Neuropharmacol 2024; 22:1189-1204. [PMID: 36740799 PMCID: PMC10964094 DOI: 10.2174/1570159x21666230203103910] [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: 10/27/2022] [Revised: 01/14/2023] [Accepted: 01/15/2023] [Indexed: 02/07/2023] Open
Abstract
The blood-brain barrier (BBB) is a highly selective interface between the blood and the brain parenchyma. It plays an essential role in maintaining a specialized environment for central nervous system function and homeostasis. The BBB disrupts with age, which contributes to the development of many age-related disorders due to central and peripheral toxic factors or BBB dysfunction. Microglia, the resident innate immune cells of the brain, have recently been explored for their ability to directly and indirectly regulate the integrity of the BBB. This review will focus on the current understanding of the molecular mechanisms utilized by microglia to regulate BBB integrity and how this becomes disrupted in aging and age-associated diseases. We will also discuss the rationale for considering microglia as a therapeutic target to prevent or slow down neurodegeneration.
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Affiliation(s)
- Simeng Zhang
- Key Laboratory of Molecular Medicine and Biotherapy, Department of Biology, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Rui Meng
- Key Laboratory of Molecular Medicine and Biotherapy, Department of Biology, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Muzhou Jiang
- Key Laboratory of Molecular Medicine and Biotherapy, Department of Biology, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
- Liaoning Provincial Key Laboratory of Oral Diseases, Department of Periodontics, School and Hospital of Stomatology, China Medical University, Shenyang, 110002, China
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy, Department of Biology, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Junjun Ni
- Key Laboratory of Molecular Medicine and Biotherapy, Department of Biology, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
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7
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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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8
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Hashimoto Y, Greene C, Munnich A, Campbell M. The CLDN5 gene at the blood-brain barrier in health and disease. Fluids Barriers CNS 2023; 20:22. [PMID: 36978081 PMCID: PMC10044825 DOI: 10.1186/s12987-023-00424-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023] Open
Abstract
The CLDN5 gene encodes claudin-5 (CLDN-5) that is expressed in endothelial cells and forms tight junctions which limit the passive diffusions of ions and solutes. The blood-brain barrier (BBB), composed of brain microvascular endothelial cells and associated pericytes and end-feet of astrocytes, is a physical and biological barrier to maintain the brain microenvironment. The expression of CLDN-5 is tightly regulated in the BBB by other junctional proteins in endothelial cells and by supports from pericytes and astrocytes. The most recent literature clearly shows a compromised BBB with a decline in CLDN-5 expression increasing the risks of developing neuropsychiatric disorders, epilepsy, brain calcification and dementia. The purpose of this review is to summarize the known diseases associated with CLDN-5 expression and function. In the first part of this review, we highlight the recent understanding of how other junctional proteins as well as pericytes and astrocytes maintain CLDN-5 expression in brain endothelial cells. We detail some drugs that can enhance these supports and are being developed or currently in use to treat diseases associated with CLDN-5 decline. We then summarise mutagenesis-based studies which have facilitated a better understanding of the physiological role of the CLDN-5 protein at the BBB and have demonstrated the functional consequences of a recently identified pathogenic CLDN-5 missense mutation from patients with alternating hemiplegia of childhood. This mutation is the first gain-of-function mutation identified in the CLDN gene family with all others representing loss-of-function mutations resulting in mis-localization of CLDN protein and/or attenuated barrier function. Finally, we summarize recent reports about the dosage-dependent effect of CLDN-5 expression on the development of neurological diseases in mice and discuss what cellular supports for CLDN-5 regulation are compromised in the BBB in human diseases.
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Affiliation(s)
- Yosuke Hashimoto
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin, D02 VF25, Ireland.
| | - Chris Greene
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin, D02 VF25, Ireland
| | - Arnold Munnich
- Institut Imagine, INSERM UMR1163, Université Paris Cité, Paris, F-75015, France
- Departments of Pediatric Neurology and Medical Genetics, Hospital Necker Enfants Malades, Université Paris Cité, Paris, F-75015, France
| | - Matthew Campbell
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin, D02 VF25, Ireland.
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9
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Huang J, Ge S, Luo D, Du R, Wang Y, Liu W, Wang G, Yin T. The endothelium permeability after bioresorbable scaffolds implantation caused by the heterogeneous expression of tight junction proteins. Mater Today Bio 2022; 16:100410. [PMID: 36090609 PMCID: PMC9450163 DOI: 10.1016/j.mtbio.2022.100410] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 11/18/2022]
Abstract
As one of the main functions of vascular endothelial cells, Vascular permeability is determined by four tight junction proteins (TJPs): Zonula Occludens-1 (ZO-1), Claudin-5, Occludin and Tricellulin. The barrier function of blood vessels will be reconstructed after they are damaged by endothelial mechanical injuries caused by vascular interventions. In this study, the effects of balloon expansion (transient mechanical injury) on four TJPs and vascular permeability were compared with those of poly-l-lactic acid bioresorbable scaffolds (BRSs) implantation (continuous mechanical stimulation). We found that BRSs do not affect vascular permeability, while the recovery of vascular barrier function was found to be only related to the mechanical injuries and repair of endothelium. Mechanical stimulation affects and accelerates the recovery process of vascular permeability with the heterogeneous expression levels of TJPs induced after BRSs implantation. Different TJPs have different sensitivity to different loyal mechanical stimuli. ZO-1 is more sensitive to shear stress and tension than to static pressure. Occludin is sensitive to static pressure and shear stress. Tricellulin is more sensitive to tension stretching. Compared with the other three TJPs, Claudin-5 can respond to mechanical stimulation, with relatively low sensitivity, though. This difference in sensitivity determines the heterogeneous expression of TJPs. Mechanical stimulation of different kinds and strengths can also cause different cell morphological changes and inflammatory reactions. As an important element affecting endothelial function, the mechanical factors emerging after BRSs implantation are worthy of more attention. The repair of vascular permeability is directly related to the type of vascular injuries, while BRSs implantation has little effect on vascular permeability. Transient and persistent mechanical stimulation is the main reason to influence the expression of TJPs. Heterogeneous expression of TJPs caused by their different sensitivity to the form of mechanical stimuli.
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10
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Fuladi S, McGuinness S, Shen L, Weber CR, Khalili-Araghi F. Molecular mechanism of claudin-15 strand flexibility: A computational study. J Gen Physiol 2022; 154:213632. [PMID: 36318156 PMCID: PMC9629798 DOI: 10.1085/jgp.202213116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 07/30/2022] [Accepted: 10/05/2022] [Indexed: 11/09/2022] Open
Abstract
Claudins are one of the major components of tight junctions that play a key role in the formation and maintenance of the epithelial barrier function. Tight junction strands are dynamic and capable of adapting their structure in response to large-scale tissue rearrangement and cellular movement. Here, we present molecular dynamics simulations of claudin-15 strands of up to 225 nm in length in two parallel lipid membranes and characterize their mechanical properties. The persistence length of claudin-15 strands is comparable with those obtained from analyses of freeze-fracture electron microscopy. Our results indicate that lateral flexibility of claudin strands is due to an interplay of three sets of interfacial interaction networks between two antiparallel double rows of claudins in the membranes. In this model, claudins are assembled into interlocking tetrameric ion channels along the strand that slide with respect to each other as the strands curve over submicrometer-length scales. These results suggest a novel molecular mechanism underlying claudin-15 strand flexibility. It also sheds light on intermolecular interactions and their role in maintaining epithelial barrier function.
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Affiliation(s)
- Shadi Fuladi
- Department of Physics, University of Illinois, Chicago, IL
| | - Sarah McGuinness
- Department of Bioengineering, University of Illinois, Chicago, IL
| | - Le Shen
- Department of Surgery, The University of Chicago, Chicago, IL
| | | | - Fatemeh Khalili-Araghi
- Department of Physics, University of Illinois, Chicago, IL,Correspondence to Fatemeh Khalili-Araghi:
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11
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Berselli A, Benfenati F, Maragliano L, Alberini G. Multiscale modelling of claudin-based assemblies: a magnifying glass for novel structures of biological interfaces. Comput Struct Biotechnol J 2022; 20:5984-6010. [DOI: 10.1016/j.csbj.2022.10.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 10/24/2022] [Accepted: 10/24/2022] [Indexed: 11/03/2022] Open
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12
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Berselli A, Alberini G, Benfenati F, Maragliano L. Computational study of ion permeation through claudin-4 paracellular channels. Ann N Y Acad Sci 2022; 1516:162-174. [PMID: 35811406 PMCID: PMC9796105 DOI: 10.1111/nyas.14856] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Claudins (Cldns) form a large family of protein homologs that are essential for the assembly of paracellular tight junctions (TJs), where they form channels or barriers with tissue-specific selectivity for permeants. In contrast to several family members whose physiological role has been identified, the function of claudin 4 (Cldn4) remains elusive, despite experimental evidence suggesting that it can form anion-selective TJ channels in the renal epithelium. Computational approaches have recently been employed to elucidate the molecular basis of Cldns' function, and hence could help in clarifying the role of Cldn4. In this work, we use structural modeling and all-atom molecular dynamics simulations to transfer two previously introduced structural models of Cldn-based paracellular complexes to Cldn4 to reproduce a paracellular anion channel. Free energy calculations for ionic transport through the pores allow us to establish the thermodynamic properties driving the ion-selectivity of the structures. While one model shows a cavity permeable to chloride and repulsive to cations, the other forms barrier to the passage of all the major physiological ions. Furthermore, our results confirm the charge selectivity role of the residue Lys65 in the first extracellular loop of the protein, rationalizing Cldn4 control of paracellular permeability.
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Affiliation(s)
- Alessandro Berselli
- Center for Synaptic Neuroscience and Technology (NSYN@UniGe)Istituto Italiano di TecnologiaGenovaItaly
- Department of Experimental MedicineUniversità degli Studi di GenovaGenovaItaly
| | - Giulio Alberini
- Center for Synaptic Neuroscience and Technology (NSYN@UniGe)Istituto Italiano di TecnologiaGenovaItaly
- IRCCS Ospedale Policlinico San MartinoGenovaItaly
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology (NSYN@UniGe)Istituto Italiano di TecnologiaGenovaItaly
- IRCCS Ospedale Policlinico San MartinoGenovaItaly
| | - Luca Maragliano
- Center for Synaptic Neuroscience and Technology (NSYN@UniGe)Istituto Italiano di TecnologiaGenovaItaly
- Department of Life and Environmental SciencesPolytechnic University of MarcheAnconaItaly
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13
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Fuladi S, McGuinness S, Khalili-Araghi F. Role of TM3 in claudin-15 strand flexibility: A molecular dynamics study. Front Mol Biosci 2022; 9:964877. [PMID: 36250014 PMCID: PMC9557151 DOI: 10.3389/fmolb.2022.964877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
Claudins are cell-cell adhesion proteins within tight junctions that connect epithelial cells together. Claudins polymerize into a network of strand-like structures within the membrane of adjoining cells and create ion channels that control paracellular permeability to water and small molecules. Tight junction morphology and barrier function is tissue specific and regulated by claudin subtypes. Here, we present a molecular dynamics study of claudin-15 strands within lipid membranes and the role of a single-point mutation (A134P) on the third transmembrane helix (TM3) of claudin-15 in determining the morphology of the strand. Our results indicate that the A134P mutation significantly affects the lateral flexibility of the strands, increasing the persistence length of claudin-15 strands by a factor of three. Analyses of claudin-claudin contact in our μsecond-long trajectories show that the mutation does not alter the intermolecular contacts (interfaces) between claudins. However, the dynamics and frequency of interfacial contacts are significantly affected. The A134P mutation introduces a kink in TM3 of claudin-15 similar to the one observed in claudin-3 crystal structure. The kink on TM3 skews the rotational flexibility of the claudins in the strands and limits their fluctuation in one direction. This asymmetric movement in the context of the double rows reduces the lateral flexibility of the strand and leads to higher persistence lengths of the mutant.
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Affiliation(s)
- Shadi Fuladi
- Department of Physics, University of Illinois at Chicago, Chicago, IL, United States
| | - Sarah McGuinness
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States
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14
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Rajagopal N, Nangia S. Unique structural features of claudin‐5 and claudin‐15 lead to functionally distinct tight junction strand architecture. Ann N Y Acad Sci 2022; 1517:225-233. [DOI: 10.1111/nyas.14891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Nandhini Rajagopal
- Department of Biomedical and Chemical Engineering Syracuse University Syracuse New York USA
| | - Shikha Nangia
- Department of Biomedical and Chemical Engineering Syracuse University Syracuse New York USA
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15
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Gonschior H, Schmied C, Van der Veen RE, Eichhorst J, Himmerkus N, Piontek J, Günzel D, Bleich M, Furuse M, Haucke V, Lehmann M. Nanoscale segregation of channel and barrier claudins enables paracellular ion flux. Nat Commun 2022; 13:4985. [PMID: 36008380 PMCID: PMC9411157 DOI: 10.1038/s41467-022-32533-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 08/04/2022] [Indexed: 11/09/2022] Open
Abstract
The paracellular passage of ions and small molecules across epithelia is controlled by tight junctions, complex meshworks of claudin polymers that form tight seals between neighboring cells. How the nanoscale architecture of tight junction meshworks enables paracellular passage of specific ions or small molecules without compromising barrier function is unknown. Here we combine super-resolution stimulated emission depletion microscopy in live and fixed cells and tissues, multivariate classification of super-resolution images and fluorescence resonance energy transfer to reveal the nanoscale organization of tight junctions formed by mammalian claudins. We show that only a subset of claudins can assemble into characteristic homotypic meshworks, whereas tight junctions formed by multiple claudins display nanoscale organization principles of intermixing, integration, induction, segregation, and exclusion of strand assemblies. Interestingly, channel-forming claudins are spatially segregated from barrier-forming claudins via determinants mainly encoded in their extracellular domains also known to harbor mutations leading to human diseases. Electrophysiological analysis of claudins in epithelial cells suggests that nanoscale segregation of distinct channel-forming claudins enables barrier function combined with specific paracellular ion flux across tight junctions. Meshworks of claudin polymers control the paracellular transport and barrier properties of epithelial tight junctions. Here, the authors show different claudin nanoscale organization principles, finding that claudin segregation enables barrier formation and paracellular ion flux across tight junctions.
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Affiliation(s)
- Hannes Gonschior
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Christopher Schmied
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | | | - Jenny Eichhorst
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Nina Himmerkus
- Institute of Physiology, Christian-Albrechts-Universität zu Kiel, 24118, Kiel, Germany
| | - Jörg Piontek
- Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203, Berlin, Germany
| | - Dorothee Günzel
- Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203, Berlin, Germany
| | - Markus Bleich
- Institute of Physiology, Christian-Albrechts-Universität zu Kiel, 24118, Kiel, Germany
| | - Mikio Furuse
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8787, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (Graduate University for Advanced Studies), Okazaki, Aichi, 444-8585, Japan
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany.,Faculty of Biology, Chemistry and Pharmacy, Freie Universität Berlin, 14195, Berlin, Germany
| | - Martin Lehmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany.
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16
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Berselli A, Alberini G, Benfenati F, Maragliano L. Computational Assessment of Different Structural Models for Claudin-5 Complexes in Blood-Brain Barrier Tight Junctions. ACS Chem Neurosci 2022; 13:2140-2153. [PMID: 35816296 PMCID: PMC9976285 DOI: 10.1021/acschemneuro.2c00139] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The blood-brain barrier (BBB) strictly regulates the exchange of ions and molecules between the blood and the central nervous system. Tight junctions (TJs) are multimeric structures that control the transport through the paracellular spaces between the adjacent brain endothelial cells of the BBB. Claudin-5 (Cldn5) proteins are essential for TJ formation and assemble into multiprotein complexes via cis-interactions within the same cell membrane and trans-interactions across two contiguous cells. Despite the relevant biological function of Cldn5 proteins and their role as targets of brain drug delivery strategies, the molecular details of their assembly within TJs are still unclear. Two different structural models have been recently introduced, in which Cldn5 dimers belonging to opposite cells join to generate paracellular pores. However, a comparison of these models in terms of ionic transport features is still lacking. In this work, we used molecular dynamics simulations and free energy (FE) calculations to assess the two Cldn5 pore models and investigate the thermodynamic properties of water and physiological ions permeating through them. Despite different FE profiles, both structures present single/multiple FE barriers to ionic permeation, while being permissive to water flux. These results reveal that both models are compatible with the physiological role of Cldn5 TJ strands. By identifying the protein-protein surface at the core of TJ Cldn5 assemblies, our computational investigation provides a basis for the rational design of synthetic peptides and other molecules capable of opening paracellular pores in the BBB.
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Affiliation(s)
- Alessandro Berselli
- Center
for Synaptic Neuroscience and Technology (NSYN@UniGe), Istituto Italiano di Tecnologia, Largo Rosanna Benzi, 10, Genova 16132, Italy
- Department
of Experimental Medicine, Università
Degli Studi di Genova, Viale Benedetto XV, 3, Genova 16132, Italy
| | - Giulio Alberini
- Center
for Synaptic Neuroscience and Technology (NSYN@UniGe), Istituto Italiano di Tecnologia, Largo Rosanna Benzi, 10, Genova 16132, Italy
- IRCCS
Ospedale Policlinico San Martino, Largo Rosanna Benzi, 10, Genova 16132, Italy
| | - Fabio Benfenati
- Center
for Synaptic Neuroscience and Technology (NSYN@UniGe), Istituto Italiano di Tecnologia, Largo Rosanna Benzi, 10, Genova 16132, Italy
- IRCCS
Ospedale Policlinico San Martino, Largo Rosanna Benzi, 10, Genova 16132, Italy
| | - Luca Maragliano
- Center
for Synaptic Neuroscience and Technology (NSYN@UniGe), Istituto Italiano di Tecnologia, Largo Rosanna Benzi, 10, Genova 16132, Italy
- Department
of Life and Environmental Sciences, Polytechnic
University of Marche, Via Brecce Bianche, Ancona 60131, Italy
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17
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Wei T, Zhou M, Gu L, Zhou Y, Li M. How Shockwaves Open Tight Junctions of Blood–Brain Barrier: Comparison of Three Biomechanical Effects. J Phys Chem B 2022; 126:5094-5102. [DOI: 10.1021/acs.jpcb.2c02903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tong Wei
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei 230026, China
- Institute of Chemical Materials, China Academy of Engineering and Physics, Mianyang 621900, China
| | - Mi Zhou
- Institute of Chemical Materials, China Academy of Engineering and Physics, Mianyang 621900, China
| | - Lingzhi Gu
- Institute of Chemical Materials, China Academy of Engineering and Physics, Mianyang 621900, China
| | - Yang Zhou
- Institute of Chemical Materials, China Academy of Engineering and Physics, Mianyang 621900, China
| | - Ming Li
- Institute of Chemical Materials, China Academy of Engineering and Physics, Mianyang 621900, China
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18
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High-Dose Acetaminophen Alters the Integrity of the Blood-Brain Barrier and Leads to Increased CNS Uptake of Codeine in Rats. Pharmaceutics 2022; 14:pharmaceutics14050949. [PMID: 35631535 PMCID: PMC9144323 DOI: 10.3390/pharmaceutics14050949] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/12/2022] [Accepted: 04/25/2022] [Indexed: 02/04/2023] Open
Abstract
The consumption of acetaminophen (APAP) can induce neurological changes in human subjects; however, effects of APAP on blood-brain barrier (BBB) integrity are unknown. BBB changes by APAP can have profound consequences for brain delivery of co-administered drugs. To study APAP effects, female Sprague-Dawley rats (12-16 weeks old) were administered vehicle (i.e., 100% dimethyl sulfoxide (DMSO), intraperitoneally (i.p.)) or APAP (80 mg/kg or 500 mg/kg in DMSO, i.p.; equivalent to a 900 mg or 5600 mg daily dose for a 70 kg human subject). BBB permeability was measured via in situ brain perfusion using [14C]sucrose and [3H]codeine, an opioid analgesic drug that is co-administered with APAP (i.e., Tylenol #3). Localization and protein expression of tight junction proteins (i.e., claudin-5, occludin, ZO-1) were studied in rat brain microvessels using Western blot analysis and confocal microscopy, respectively. Paracellular [14C]sucrose "leak" and brain [3H]codeine accumulation were significantly enhanced in rats treated with 500 mg/kg APAP only. Additionally, claudin-5 localization and protein expression were altered in brain microvessels isolated from rats administered 500 mg/kg APAP. Our novel and translational data show that BBB integrity is altered following a single high APAP dose, results that are relevant to patients abusing or misusing APAP and/or APAP/opioid combination products.
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19
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The blood-brain barrier in aging and neurodegeneration. Mol Psychiatry 2022; 27:2659-2673. [PMID: 35361905 PMCID: PMC9156404 DOI: 10.1038/s41380-022-01511-z] [Citation(s) in RCA: 169] [Impact Index Per Article: 84.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 01/24/2022] [Accepted: 02/24/2022] [Indexed: 12/01/2022]
Abstract
The blood-brain barrier (BBB) is vital for maintaining brain homeostasis by enabling an exquisite control of exchange of compounds between the blood and the brain parenchyma. Moreover, the BBB prevents unwanted toxins and pathogens from entering the brain. This barrier, however, breaks down with age and further disruption is a hallmark of many age-related disorders. Several drugs have been explored, thus far, to protect or restore BBB function. With the recent connection between the BBB and gut microbiota, microbial-derived metabolites have been explored for their capabilities to protect and restore BBB physiology. This review, will focus on the vital components that make up the BBB, dissect levels of disruption of the barrier, and discuss current drugs and therapeutics that maintain barrier integrity and the recent discoveries of effects microbial-derived metabolites have on BBB physiology.
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20
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Hashimoto Y, Campbell M, Tachibana K, Okada Y, Kondoh M. Claudin-5: A Pharmacological Target to Modify the Permeability of the Blood-Brain Barrier. Biol Pharm Bull 2021; 44:1380-1390. [PMID: 34602546 DOI: 10.1248/bpb.b21-00408] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Claudin-5 is the dominant tight junction protein in brain endothelial cells and exclusively limits the paracellular permeability of molecules larger than 400 Da across the blood-brain barrier (BBB). Its pathological impairment or sustained down-regulation has been shown to lead to the progression of psychiatric and neurological disorders, whereas its expression under physiological conditions prevents the passage of drugs across the BBB. While claudin-5 enhancers could potentially act as vascular stabilizers to treat neurological diseases, claudin-5 inhibitors could function as delivery systems to enhance the brain uptake of hydrophilic small-molecular-weight drugs. Therefore, the effects of claudin-5 manipulation on modulating the BBB in different neurological diseases requires further examination. To manipulate claudin-5 expression levels and function, several claudin-5 modulating molecules have been developed. In this review, we first describe the molecular, cellular and pathological aspects of claudin-5 to highlight the mechanisms of claudin-5 enhancers/inhibitors. We then discuss recently developed claudin-5 enhancers/inhibitors and new methods to discover these molecules.
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Affiliation(s)
| | | | | | - Yoshiaki Okada
- Graduate School of Pharmaceutical Sciences, Osaka University
| | - Masuo Kondoh
- Graduate School of Pharmaceutical Sciences, Osaka University
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21
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Li J. Context-Dependent Roles of Claudins in Tumorigenesis. Front Oncol 2021; 11:676781. [PMID: 34354941 PMCID: PMC8329526 DOI: 10.3389/fonc.2021.676781] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 07/05/2021] [Indexed: 12/16/2022] Open
Abstract
The barrier and fence functions of the claudin protein family are fundamental to tissue integrity and human health. Increasing evidence has linked claudins to signal transduction and tumorigenesis. The expression of claudins is frequently dysregulated in the context of neoplastic transformation. Studies have uncovered that claudins engage in nearly all aspects of tumor biology and steps of tumor development, suggesting their promise as targets for treatment or biomarkers for diagnosis and prognosis. However, claudins can be either tumor promoters or tumor suppressors depending on the context, which emphasizes the importance of taking various factors, including organ type, environmental context and genetic confounders, into account when studying the biological functions and targeting of claudins in cancer. This review discusses the complicated roles and intrinsic and extrinsic determinants of the context-specific effects of claudins in cancer.
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Affiliation(s)
- Jian Li
- Department of General Surgery, The Third Hospital of Mianyang, Sichuan Mental Health Center, Mianyang, China
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22
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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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23
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Brunner N, Stein L, Cornelius V, Knittel R, Fallier-Becker P, Amasheh S. Blood-Brain Barrier Protein Claudin-5 Expressed in Paired Xenopus laevis Oocytes Mediates Cell-Cell Interaction. Front Physiol 2020; 11:857. [PMID: 32848831 PMCID: PMC7396581 DOI: 10.3389/fphys.2020.00857] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 06/26/2020] [Indexed: 01/08/2023] Open
Abstract
Claudin-5 determines the sealing properties of blood-brain barrier tight junctions and its function is impaired in neurodegenerative and neuroinflammatory disorders. Focusing on the contribution of claudin-5 to the trans-interaction within the tight junction seal, we used Xenopus laevis oocytes as an expression system. Cells were clustered and challenged in a novel approach for the analysis of claudin interaction. We evaluated the strengthening effect of claudin-5 to cell-cell-connection in comparison to claudin-3. Application of a hydrostatic pressure impulse on clustered control oocyte pairs revealed a reduction of contact areas. In contrast, combinations with both oocytes expressing claudins maintained an enhanced connection between the cells (cldn5-cldn5, cldn3-cldn3). Strength of interaction was increased by both claudin-3 and claudin-5. This novel approach allowed an analysis of single claudins contributing to tight junction integrity, characterizing homophilic and hetrophilic trans-interaction of claudins. To test a new screening approach for barrier effectors, exemplarily, this 2-cell model of oocytes was used to analyze the effect of the absorption enhancer sodium caprate on the oocyte pairs.
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Affiliation(s)
- Nora Brunner
- Department of Veterinary Medicine, Institute of Veterinary Physiology, Freie Universität Berlin, Berlin, Germany
| | - Laura Stein
- Department of Veterinary Medicine, Institute of Veterinary Physiology, Freie Universität Berlin, Berlin, Germany
| | - Valeria Cornelius
- Department of Veterinary Medicine, Institute of Veterinary Physiology, Freie Universität Berlin, Berlin, Germany
| | - Ria Knittel
- Institute of Pathology and Neuropathology, University Hospital of Tuebingen, Eberhard Karls University of Tuebingen, Tuebingen, Germany
| | - Petra Fallier-Becker
- Institute of Pathology and Neuropathology, University Hospital of Tuebingen, Eberhard Karls University of Tuebingen, Tuebingen, Germany
| | - Salah Amasheh
- Department of Veterinary Medicine, Institute of Veterinary Physiology, Freie Universität Berlin, Berlin, Germany
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24
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Baumholtz AI, De Marco P, Capra V, Ryan AK. Functional Validation of CLDN Variants Identified in a Neural Tube Defect Cohort Demonstrates Their Contribution to Neural Tube Defects. Front Neurosci 2020; 14:664. [PMID: 32760237 PMCID: PMC7372130 DOI: 10.3389/fnins.2020.00664] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 05/29/2020] [Indexed: 12/27/2022] Open
Abstract
Neural tube defects (NTDs) are severe malformations of the central nervous system that affect 1–2 individuals per 2,000 births. Their etiology is complex and involves both genetic and environmental factors. Our recent discovery that simultaneous removal of Cldn3, -4, and -8 from tight junctions results in cranial and spinal NTDs in both chick and mouse embryos suggests that claudins play a conserved role in neural tube closure in vertebrates. To determine if claudins were associated with NTDs in humans, we used a Fluidigm next generation sequencing approach to identify genetic variants in CLDN loci in 152 patients with spinal NTDs. We identified eleven rare and four novel missense mutations in ten CLDN genes. In vivo validation of variant pathogenicity using a chick embryo model system revealed that overexpression of four variants caused a significant increase in NTDs: CLDN3 A128T, CLDN8 P216L, CLDN19 I22T, and E209G. Our data implicate rare missense variants in CLDN genes as risk factors for spinal NTDs and suggest a new family of proteins involved in the pathogenesis of these malformations.
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Affiliation(s)
- Amanda I Baumholtz
- Department of Human Genetics, McGill University, Montreal, QC, Canada.,The Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Patrizia De Marco
- Laboratorio di Neurogenetica e Neuroscienze, Istituto Giannina Gaslini, Genoa, Italy
| | - Valeria Capra
- U.O. Neurochirurgia, Istituto Giannina Gaslini, Genoa, Italy
| | - Aimee K Ryan
- Department of Human Genetics, McGill University, Montreal, QC, Canada.,The Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Department of Pediatrics, McGill University, Montreal, QC, Canada
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25
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Hashimoto Y, Campbell M. Tight junction modulation at the blood-brain barrier: Current and future perspectives. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183298. [PMID: 32353377 DOI: 10.1016/j.bbamem.2020.183298] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/09/2020] [Accepted: 03/28/2020] [Indexed: 12/14/2022]
Abstract
The blood-brain barrier (BBB) is the one of the most robust physical barriers in the body, comprised of tight junction (TJ) proteins in brain microvascular endothelial cells. The need for drugs to treat central nervous systems diseases is ever increasing, however the presence of the BBB significantly hampers the uptake of drugs into the brain. To overcome or circumvent the barrier, many kinds of techniques are being developed. Modulating the paracellular route by disruption of the TJ complex has been proposed as a potential drug delivery system to treat brain diseases, however, it has several limitations and is still in a developmental stage. However, recent significant advance in medical equipment /tools such as targeted ultra-sound technologies may resolve these limitations. In this review, we introduce recent advances in site- or molecular size-selective BBB disruption/modulation technologies and we include details on pharmacological inhibitory molecules against intercellular TJ proteins to modulate the BBB.
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Affiliation(s)
- Yosuke Hashimoto
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland.
| | - Matthew Campbell
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland.
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26
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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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27
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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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28
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Fuladi S, Jannat RW, Shen L, Weber CR, Khalili-Araghi F. Computational Modeling of Claudin Structure and Function. Int J Mol Sci 2020; 21:ijms21030742. [PMID: 31979311 PMCID: PMC7037046 DOI: 10.3390/ijms21030742] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/16/2020] [Accepted: 01/16/2020] [Indexed: 12/18/2022] Open
Abstract
Tight junctions form a barrier to control passive transport of ions and small molecules across epithelia and endothelia. In addition to forming a barrier, some of claudins control transport properties of tight junctions by forming charge- and size-selective ion channels. It has been suggested claudin monomers can form or incorporate into tight junction strands to form channels. Resolving the crystallographic structure of several claudins in recent years has provided an opportunity to examine structural basis of claudins in tight junctions. Computational and theoretical modeling relying on atomic description of the pore have contributed significantly to our understanding of claudin pores and paracellular transport. In this paper, we review recent computational and mathematical modeling of claudin barrier function. We focus on dynamic modeling of global epithelial barrier function as a function of claudin pores and molecular dynamics studies of claudins leading to a functional model of claudin channels.
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Affiliation(s)
- Shadi Fuladi
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA; (S.F.); (R.-W.J.)
| | - Ridaka-Wal Jannat
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA; (S.F.); (R.-W.J.)
| | - Le Shen
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA;
- Department of Surgery, University of Chicago, Chicago, IL 60637, USA
| | - Christopher R. Weber
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA;
- Correspondence: (C.R.W.); (F.K.-A.)
| | - Fatemeh Khalili-Araghi
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA; (S.F.); (R.-W.J.)
- Correspondence: (C.R.W.); (F.K.-A.)
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29
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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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Potential for Tight Junction Protein-Directed Drug Development Using Claudin Binders and Angubindin-1. Int J Mol Sci 2019; 20:ijms20164016. [PMID: 31426497 PMCID: PMC6719960 DOI: 10.3390/ijms20164016] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 08/14/2019] [Accepted: 08/14/2019] [Indexed: 12/30/2022] Open
Abstract
The tight junction (TJ) is an intercellular sealing component found in epithelial and endothelial tissues that regulates the passage of solutes across the paracellular space. Research examining the biology of TJs has revealed that they are complex biochemical structures constructed from a range of proteins including claudins, occludin, tricellulin, angulins and junctional adhesion molecules. The transient disruption of the barrier function of TJs to open the paracellular space is one means of enhancing mucosal and transdermal drug absorption and to deliver drugs across the blood–brain barrier. However, the disruption of TJs can also open the paracellular space to harmful xenobiotics and pathogens. To address this issue, the strategies targeting TJ proteins have been developed to loosen TJs in a size- or tissue-dependent manner rather than to disrupt them. As several TJ proteins are overexpressed in malignant tumors and in the inflamed intestinal tract, and are present in cells and epithelia conjoined with the mucosa-associated lymphoid immune tissue, these TJ-protein-targeted strategies may also provide platforms for the development of novel therapies and vaccines. Here, this paper reviews two TJ-protein-targeted technologies, claudin binders and an angulin binder, and their applications in drug development.
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Liu F, Liu Q, Yuan F, Guo S, Liu J, Sun Z, Gao P, Wang Y, Yan S, Liu J. Erg mediates downregulation of claudin-5 in the brain endothelium of a murine experimental model of cerebral malaria. FEBS Lett 2019; 593:2585-2595. [PMID: 31271645 DOI: 10.1002/1873-3468.13526] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 12/17/2022]
Abstract
Cerebral malaria (CM) is a severe complication with brain vascular hyperpermeability. Claudin-5 is the major component of tight junctions. To investigate the expression of claudin-5 in CM, we established a murine experimental cerebral malaria (ECM) model and an in vitro model by treating murine brain endothelial cells (bEnd3) with plasma from ECM mice. Expression of claudin-5 and the ETS transcription factor Erg was reduced in the brain endothelium of ECM mice. In bEnd3 cells exposed to ECM plasma, decreased expression of claudin-5 and Erg, and increased permeability were observed. Silencing of Erg significantly reduced Cldn5 expression. ChIP assays indicated that Erg binds to the -813 ETS motif of the murine Cldn5 gene promoter, and the binding is decreased by treatment with ECM plasma.
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Affiliation(s)
- Fuhong Liu
- Laboratory of Microvascular Medicine, Medical Research Center, Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan, China
| | - Qiang Liu
- Laboratory of Microvascular Medicine, Medical Research Center, Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan, China
| | - Fangshu Yuan
- Department of Human Parasitology, School of Medicine, Shandong University, Jinan, China
| | - Shuling Guo
- Department of Human Parasitology, School of Medicine, Shandong University, Jinan, China
| | - Jinzhi Liu
- Department of Neurology, Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan, China
| | - Zongguo Sun
- Laboratory of Microvascular Medicine, Medical Research Center, Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan, China
| | - Peng Gao
- Laboratory of Microvascular Medicine, Medical Research Center, Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan, China
| | - Yu Wang
- School of Medicine, Shandong University, Jinan, China
| | - Suhua Yan
- Department of Cardiology, Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan, China
| | - Ju Liu
- Laboratory of Microvascular Medicine, Medical Research Center, Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan, China
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Tsukita S, Tanaka H, Tamura A. The Claudins: From Tight Junctions to Biological Systems. Trends Biochem Sci 2019; 44:141-152. [DOI: 10.1016/j.tibs.2018.09.008] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/17/2018] [Accepted: 09/19/2018] [Indexed: 01/04/2023]
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Greene C, Hanley N, Campbell M. Claudin-5: gatekeeper of neurological function. Fluids Barriers CNS 2019; 16:3. [PMID: 30691500 PMCID: PMC6350359 DOI: 10.1186/s12987-019-0123-z] [Citation(s) in RCA: 280] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 01/11/2019] [Indexed: 02/07/2023] Open
Abstract
Tight junction proteins of the blood–brain barrier are vital for maintaining integrity of endothelial cells lining brain blood vessels. The presence of these protein complexes in the space between endothelial cells creates a dynamic, highly regulated and restrictive microenvironment that is vital for neural homeostasis. By limiting paracellular diffusion of material between blood and brain, tight junction proteins provide a protective barrier preventing the passage of unwanted and potentially damaging material. Simultaneously, this protective barrier hinders the therapeutic effectiveness of central nervous system acting drugs with over 95% of small molecule therapeutics unable to bypass the blood–brain barrier. At the blood–brain barrier, claudin-5 is the most enriched tight junction protein and its dysfunction has been implicated in neurodegenerative disorders such as Alzheimer’s disease, neuroinflammatory disorders such as multiple sclerosis as well as psychiatric disorders including depression and schizophrenia. By regulating levels of claudin-5, it is possible to abrogate disease symptoms in many of these disorders. This review will give an overview of the blood–brain barrier and the role of tight junction complexes in maintaining blood–brain barrier integrity before focusing on the role of claudin-5 and its regulation in homeostatic and pathological conditions. We will also summarise therapeutic strategies to restore integrity of cerebral vessels by targeting tight junction protein complexes.
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Affiliation(s)
- Chris Greene
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland
| | - Nicole Hanley
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland
| | - Matthew Campbell
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland.
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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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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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Samanta P, Wang Y, Fuladi S, Zou J, Li Y, Shen L, Weber C, Khalili-Araghi F. Molecular determination of claudin-15 organization and channel selectivity. J Gen Physiol 2018; 150:949-968. [PMID: 29915162 PMCID: PMC6028499 DOI: 10.1085/jgp.201711868] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 03/08/2018] [Accepted: 05/04/2018] [Indexed: 12/28/2022] Open
Abstract
Members of the claudin family form tight junctions between adjacent epithelial and endothelial cells. Samanta et al. build an atomic model of claudin-15 using molecular dynamics simulations and conclude that four claudin-15 molecules each contribute an aspartic acid residue to form a selectivity filter. Tight junctions are macromolecular structures that traverse the space between adjacent cells in epithelia and endothelia. Members of the claudin family are known to determine tight junction permeability in a charge- and size-selective manner. Here, we use molecular dynamics simulations to build and refine an atomic model of claudin-15 channels and study its transport properties. Our simulations indicate that claudin-15 forms well-defined channels for ions and molecules and otherwise “seals” the paracellular space through hydrophobic interactions. Ionic currents, calculated from simulation trajectories of wild-type as well as mutant channels, reflect in vitro measurements. The simulations suggest that the selectivity filter is formed by a cage of four aspartic acid residues (D55), contributed by four claudin-15 molecules, which creates a negative electrostatic potential to favor cation flux over anion flux. Charge reversal or charge ablation mutations of D55 significantly reduce cation permeability in silico and in vitro, whereas mutations of other negatively charged pore amino acid residues have a significantly smaller impact on channel permeability and selectivity. The simulations also indicate that water and small ions can pass through the channel, but larger cations, such as tetramethylammonium, do not traverse the pore. Thus, our model provides an atomic view of claudin channels, their transport function, and a potential three-dimensional organization of its selectivity filter.
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Affiliation(s)
| | - Yitang Wang
- Department of Pathology, The University of Chicago, Chicago, IL.,Department of Surgery, The University of Chicago, Chicago, IL
| | - Shadi Fuladi
- Department of Physics, University of Illinois, Chicago, IL
| | - Jinjing Zou
- Department of Pathology, The University of Chicago, Chicago, IL
| | - Ye Li
- Department of Pathology, The University of Chicago, Chicago, IL
| | - Le Shen
- Department of Pathology, The University of Chicago, Chicago, IL .,Department of Surgery, The University of Chicago, Chicago, IL
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Irudayanathan FJ, Wang X, Wang N, Willsey SR, Seddon IA, Nangia S. Self-Assembly Simulations of Classic Claudins—Insights into the Pore Structure, Selectivity, and Higher Order Complexes. J Phys Chem B 2018; 122:7463-7474. [DOI: 10.1021/acs.jpcb.8b03842] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Xiaoyi Wang
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Nan Wang
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Sarah R. Willsey
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Ian A. Seddon
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
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Engineered membrane protein antigens successfully induce antibodies against extracellular regions of claudin-5. Sci Rep 2018; 8:8383. [PMID: 29849184 PMCID: PMC5976803 DOI: 10.1038/s41598-018-26560-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 05/15/2018] [Indexed: 01/09/2023] Open
Abstract
The production of antibodies against the extracellular regions (ECR) of multispanning membrane proteins is notoriously difficult because of the low productivity and immunogenicity of membrane proteins due to their complex structure and highly conserved sequences among species. Here, we introduce a new method to generate ECR-binding antibodies utilizing engineered liposomal immunogen prepared using a wheat cell-free protein synthesis system. We used claudin-5 (CLDN-5) as the target antigen, which is a notoriously difficult to produce and poorly immunogenic membrane protein with two highly conserved extracellular loops. We drastically improved the productivity of CLDN-5 in the cell-free system after suppressing and normalizing mRNA GC content. To overcome its low immunogenicity, two engineered antigens were designed and synthesized as proteoliposomes: a human/mouse chimeric CLDN-5, and a CLDN-5-based artificial membrane protein consisting of symmetrically arranged ECRs. Intraperitoneal immunization of both engineered CLDN-5 ECR antigens induced ECR-binding antibodies in mice with a high success rate. We isolated five monoclonal antibodies that specifically recognized CLDN-5 ECR. Antibody clone 2B12 showed high affinity (<10 nM) and inhibited CLDN-5-containing tight junctions. These results demonstrate the effectiveness of the methods for monoclonal antibody development targeting difficult-to-produce membrane proteins such as CLDNs.
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Zhao J, Krystofiak ES, Ballesteros A, Cui R, Van Itallie CM, Anderson JM, Fenollar-Ferrer C, Kachar B. Multiple claudin-claudin cis interfaces are required for tight junction strand formation and inherent flexibility. Commun Biol 2018; 1:50. [PMID: 30271933 PMCID: PMC6123731 DOI: 10.1038/s42003-018-0051-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 04/03/2018] [Indexed: 02/07/2023] Open
Abstract
Tight junctions consist of a network of sealing strands that create selective ion permeability barriers between adjoining epithelial or endothelial cells. The current model for tight junction strands consists of paired rows of claudins (Cldn) coupled by a cis interface (X-1) derived from crystalline Cldn15. Here we show that tight junction strands exhibit a broad range of lateral bending, indicating diversity in cis interactions. By combining protein–protein docking, coevolutionary analysis, molecular dynamics, and a mutagenesis screen, we identify a new Cldn–Cldn cis interface (Cis-1) that shares interacting residues with X-1 but has an ~ 17° lateral rotation between monomers. In addition, we found that a missense mutation in a Cldn14 that causes deafness and contributes stronger to Cis-1 than to X-1 prevents strand formation in cultured cells. Our results suggest that Cis-1 contributes to the inherent structural flexibility of tight junction strands and is required for maintaining permeability barrier function and hearing. Jun Zhao, Evan S. Krystofiak, and colleagues identified a new cis interface (Cis-1) essential for the formation of normal tight junctions. This study suggests that Cis-1 contributes to maintaining structural flexibility of tight junction strands for proper ion balance and hearing.
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Affiliation(s)
- Jun Zhao
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, 35A Convent Drive, Bethesda, MD, 20892, USA.,Cancer and Inflammation Program, National Cancer Institute, Frederick, MD, 21702, USA
| | - Evan S Krystofiak
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, 35A Convent Drive, Bethesda, MD, 20892, USA
| | - Angela Ballesteros
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, 35A Convent Drive, Bethesda, MD, 20892, USA.,Molecular Physiology and Biophysics Section, National Institute of Neurological Disorders and Stroke, Bethesda, MD, 20892, USA
| | - Runjia Cui
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, 35A Convent Drive, Bethesda, MD, 20892, USA
| | - Christina M Van Itallie
- Laboratory of Tight Junction Structure and Function, National Heart, Lung, and Blood Institute, 50 South Drive, Bethesda, MD, 20892, USA
| | - James M Anderson
- Laboratory of Tight Junction Structure and Function, National Heart, Lung, and Blood Institute, 50 South Drive, Bethesda, MD, 20892, USA
| | - Cristina Fenollar-Ferrer
- Computational Structural Biology Unit, National Institute of Neurological Disorders and Stroke, 35 Convent Drive, Bethesda, MD, 20892, USA. .,Laboratory of Molecular & Cellular Neurobiology, National Institute of Mental Health, 35 Convent Drive, Bethesda, MD, 20892, USA.
| | - Bechara Kachar
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, 35A Convent Drive, Bethesda, MD, 20892, USA.
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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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Dong T, Chen N, Ma X, Wang J, Wen J, Xie Q, Ma R. The protective roles of L-borneolum, D-borneolum and synthetic borneol in cerebral ischaemia via modulation of the neurovascular unit. Biomed Pharmacother 2018; 102:874-883. [PMID: 29728011 DOI: 10.1016/j.biopha.2018.03.087] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 03/14/2018] [Accepted: 03/14/2018] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE Borneol has been used to treat stroke in China since ancient times. In our previous research, we demonstrated the effect of borneol on cerebral ischaemia injury via meta-analysis. The neurovascular unit (NVU) is the structural basis of the preservation of the brain microenvironment and is believed to be a promising target in treating stroke. In this research, we explored the roles of three kinds of borneol, namely, L-borneolum (B1), D-borneolum (B2) and synthetic borneol (B3), in the NVU with permanent middle cerebral artery occluded (pMCAO) rats. METHODS The Longa scoring method was used to evaluate nerve function deficits in the pMCAO rats. Awakening time, brain water content, brain index and brain edema rate were also measured. TTC staining was used to calculate the cerebral infarction rate. The morphology of the ischaemia penumbra brain tissue was observed via HE staining, and the neuronal denatured cell index (DCI) was calculated. An enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of vascular endothelial growth factor VEGF and TNF-α in the serum. Moreover, the ultrastructures of the neurons and of the blood-brain barrier (BBB) were observed using transmission electron microscopy. The expression levels of Claudin-5, Bcl-2 and Bax in the ischaemia penumbra of pMCAO rats were detected using real-time PCR and immunohistochemistry. RESULTS Pretreatment with B1, B2 and B3 delayed the recovery time (P < 0.01). B1 remarkably ameliorated neurological deficits 24 h after cerebral ischaemia (P < 0.05). Moreover, B1 and B3 were both able to ameliorate brain edema and the area of cerebral infarction. In addition, B1, B2 and B3 all increased serum VEGF levels and decreased serum TNF-α levels (P < 0.01). For the ultrastructure determination, the BBB and the nerve centre were significantly improved by B1, B2 and B3. The mechanistic exploration revealed that B2 and B3 protected the brain by reducing the Bax/Bcl-2 ratio (P < 0.05, P < 0.01, respectively). Immunohistochemistry suggested that B1, B2 and B3 could also enhance the expression of Claudin-5 (P < 0.01). CONCLUSION The three kinds of borneol demonstrated different protective effects on cerebral ischaemia injury. L-Borneolum displayed the most prominent anti-cerebral ischaemia effect among them. The mechanism was most likely executed via anti-apoptosis and anti-inflammation effects and maintenance of the stability of the BBB and TJs to comprehensively improve NVU function.
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Affiliation(s)
- Taiwei Dong
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Nian Chen
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Xiao Ma
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Jian Wang
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
| | - Jing Wen
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Qian Xie
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Rong Ma
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
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Neuhaus W, Piontek A, Protze J, Eichner M, Mahringer A, Subileau EA, Lee IFM, Schulzke JD, Krause G, Piontek J. Reversible opening of the blood-brain barrier by claudin-5-binding variants of Clostridium perfringens enterotoxin's claudin-binding domain. Biomaterials 2018; 161:129-143. [DOI: 10.1016/j.biomaterials.2018.01.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 01/15/2018] [Accepted: 01/18/2018] [Indexed: 02/06/2023]
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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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44
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Freeze fracture: new avenues for the ultrastructural analysis of cells in vitro. Histochem Cell Biol 2017; 149:3-13. [PMID: 29134300 DOI: 10.1007/s00418-017-1617-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2017] [Indexed: 01/02/2023]
Abstract
The ultrastructural analysis of biological membranes by freeze fracture has a 60-year tradition. In this review, we summarize the benefits of the freeze-fracture technique and review special structures analyzed by freeze fracture and by combined freeze-fracture replica immunogold labeling (FRIL) of cell cultures. In principle, every cellular membrane whether of cell suspensions, mono- or bilayers of cell cultures can be analyzed in freeze fracture. The combination of freeze fracture and immunogold labeling of the replica allows the ultrastructural identification of protein assemblies in combination with the molecular identification of their constituent proteins using specific antibodies. The analysis of fractured and labeled intramembrane particles enables determination of the arrangement and organization of proteins within the membrane due to the high resolution of the transmission electron microscope. Because of cell-specific ultrastructural features such as square arrays, identification of cell types can be performed in parallel. This review is aimed at presenting the possibilities of freeze fracture and FRIL in the high-resolution ultrastructural analysis of membrane proteins and their assembly in naïve, transfected or otherwise treated cultured cells. At the interface of molecular approaches and morphology, the application of FRIL in genetically modified cells provides a novel and intriguing aspect for their analysis.
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45
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Abstract
The claudin family of tetraspan transmembrane proteins is essential for tight junction formation and regulation of paracellular transport between epithelial cells. Claudins also play a role in apical-basal cell polarity, cell adhesion and link the tight junction to the actin cytoskeleton to exert effects on cell shape. The function of claudins in paracellular transport has been extensively studied through loss-of-function and gain-of-function studies in cell lines and in animal models, however, their role in morphogenesis has been less appreciated. In this review, we will highlight the importance of claudins during morphogenesis by specifically focusing on their critical functions in generating epithelial tubes, lumens, and tubular networks during organ formation.
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Affiliation(s)
- Amanda I Baumholtz
- a Department of Human Genetics , McGill University , Montréal , Québec , Canada.,b The Research Institute of the McGill University Health Centre , Montréal , Québec , Canada
| | - Indra R Gupta
- a Department of Human Genetics , McGill University , Montréal , Québec , Canada.,b The Research Institute of the McGill University Health Centre , Montréal , Québec , Canada.,c Department of Pediatrics , McGill University , Montréal , Québec , Canada
| | - Aimee K Ryan
- a Department of Human Genetics , McGill University , Montréal , Québec , Canada.,b The Research Institute of the McGill University Health Centre , Montréal , Québec , Canada.,c Department of Pediatrics , McGill University , Montréal , Québec , Canada
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46
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Klar J, Piontek J, Milatz S, Tariq M, Jameel M, Breiderhoff T, Schuster J, Fatima A, Asif M, Sher M, Mäbert K, Fromm A, Baig SM, Günzel D, Dahl N. Altered paracellular cation permeability due to a rare CLDN10B variant causes anhidrosis and kidney damage. PLoS Genet 2017; 13:e1006897. [PMID: 28686597 PMCID: PMC5521874 DOI: 10.1371/journal.pgen.1006897] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 07/21/2017] [Accepted: 06/26/2017] [Indexed: 02/06/2023] Open
Abstract
Claudins constitute the major component of tight junctions and regulate paracellular permeability of epithelia. Claudin-10 occurs in two major isoforms that form paracellular channels with ion selectivity. We report on two families segregating an autosomal recessive disorder characterized by generalized anhidrosis, severe heat intolerance and mild kidney failure. All affected individuals carry a rare homozygous missense mutation c.144C>G, p.(N48K) specific for the claudin-10b isoform. Immunostaining of sweat glands from patients suggested that the disease is associated with reduced levels of claudin-10b in the plasma membranes and in canaliculi of the secretory portion. Expression of claudin-10b N48K in a 3D cell model of sweat secretion indicated perturbed paracellular Na+ transport. Analysis of paracellular permeability revealed that claudin-10b N48K maintained cation over anion selectivity but with a reduced general ion conductance. Furthermore, freeze fracture electron microscopy showed that claudin-10b N48K was associated with impaired tight junction strand formation and altered cis-oligomer formation. These data suggest that claudin-10b N48K causes anhidrosis and our findings are consistent with a combined effect from perturbed TJ function and increased degradation of claudin-10b N48K in the sweat glands. Furthermore, affected individuals present with Mg2+ retention, secondary hyperparathyroidism and mild kidney failure that suggest a disturbed reabsorption of cations in the kidneys. These renal-derived features recapitulate several phenotypic aspects detected in mice with kidney specific loss of both claudin-10 isoforms. Our study adds to the spectrum of phenotypes caused by tight junction proteins and demonstrates a pivotal role for claudin-10b in maintaining paracellular Na+ permeability for sweat production and kidney function.
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Affiliation(s)
- Joakim Klar
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Jörg Piontek
- Institute of Clinical Physiology, Charité-Universitätsmedizin Berlin, Charité, Berlin, Germany
| | - Susanne Milatz
- Institute of Clinical Physiology, Charité-Universitätsmedizin Berlin, Charité, Berlin, Germany
| | - Muhammad Tariq
- Human Molecular Genetics Laboratory, National Institute for Biotechnology and Genetic Engineering (NIBGE), PIEAS, Faisalabad, Pakistan
| | - Muhammad Jameel
- Human Molecular Genetics Laboratory, National Institute for Biotechnology and Genetic Engineering (NIBGE), PIEAS, Faisalabad, Pakistan
| | - Tilman Breiderhoff
- Department of Pediatric Nephrology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Jens Schuster
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Ambrin Fatima
- Human Molecular Genetics Laboratory, National Institute for Biotechnology and Genetic Engineering (NIBGE), PIEAS, Faisalabad, Pakistan
| | - Maria Asif
- Human Molecular Genetics Laboratory, National Institute for Biotechnology and Genetic Engineering (NIBGE), PIEAS, Faisalabad, Pakistan
| | - Muhammad Sher
- Human Molecular Genetics Laboratory, National Institute for Biotechnology and Genetic Engineering (NIBGE), PIEAS, Faisalabad, Pakistan
| | - Katrin Mäbert
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Anja Fromm
- Institute of Clinical Physiology, Charité-Universitätsmedizin Berlin, Charité, Berlin, Germany
| | - Shahid M Baig
- Human Molecular Genetics Laboratory, National Institute for Biotechnology and Genetic Engineering (NIBGE), PIEAS, Faisalabad, Pakistan
| | - Dorothee Günzel
- Institute of Clinical Physiology, Charité-Universitätsmedizin Berlin, Charité, Berlin, Germany
| | - Niklas Dahl
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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Díaz-Coránguez M, Ramos C, Antonetti DA. The inner blood-retinal barrier: Cellular basis and development. Vision Res 2017; 139:123-137. [PMID: 28619516 DOI: 10.1016/j.visres.2017.05.009] [Citation(s) in RCA: 163] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/26/2017] [Accepted: 05/30/2017] [Indexed: 01/01/2023]
Abstract
The blood-retinal barrier (BRB) regulates transport across retinal capillaries maintaining proper neural homeostasis and protecting the neural tissue from potential blood borne toxicity. Loss of the BRB contributes to the pathophysiology of a number of blinding retinal diseases including diabetic retinopathy. In this review, we address the basis of the BRB, including the molecular mechanisms that regulate flux across the retinal vascular bed. The routes of transcellular and paracellular flux are described as well as alterations in these pathways in response to permeabilizing agents in diabetes. Finally, we provide information on exciting new studies that help to elucidate the process of BRB development or barriergenesis and how understanding this process may lead to new opportunities for barrier restoration in diabetic retinopathy.
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Affiliation(s)
- Mónica Díaz-Coránguez
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, United States
| | - Carla Ramos
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, United States
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, United States.
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48
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Milatz S, Piontek J, Hempel C, Meoli L, Grohe C, Fromm A, Lee IFM, El-Athman R, Günzel D. Tight junction strand formation by claudin-10 isoforms and claudin-10a/-10b chimeras. Ann N Y Acad Sci 2017. [DOI: 10.1111/nyas.13393] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Susanne Milatz
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
- Institute of Physiology; Christian-Albrechts-University Kiel; Kiel Germany
| | - Jörg Piontek
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Caroline Hempel
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Luca Meoli
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Christoph Grohe
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Anja Fromm
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - In-Fah M. Lee
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Rukeia El-Athman
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
- Institute of Physiology; Christian-Albrechts-University Kiel; Kiel Germany
| | - Dorothee Günzel
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
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49
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Irudayanathan FJ, Wang N, Wang X, Nangia S. Architecture of the paracellular channels formed by claudins of the blood–brain barrier tight junctions. Ann N Y Acad Sci 2017; 1405:131-146. [DOI: 10.1111/nyas.13378] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/12/2017] [Accepted: 04/14/2017] [Indexed: 01/31/2023]
Affiliation(s)
| | - Nan Wang
- Department of Biomedical and Chemical Engineering Syracuse University Syracuse New York
| | - Xiaoyi Wang
- Department of Biomedical and Chemical Engineering Syracuse University Syracuse New York
| | - Shikha Nangia
- Department of Biomedical and Chemical Engineering Syracuse University Syracuse New York
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50
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Suzuki H, Tani K, Fujiyoshi Y. Crystal structures of claudins: insights into their intermolecular interactions. Ann N Y Acad Sci 2017; 1397:25-34. [PMID: 28605828 DOI: 10.1111/nyas.13371] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 04/06/2017] [Accepted: 04/10/2017] [Indexed: 12/14/2022]
Abstract
Claudins are four-transmembrane proteins that constitute the backbone of tight junction strands via self-polymerization in the apicolateral membranes of epithelial cells. Together with their cell-cell adhesion function, claudin proteins form the paracellular barrier and/or channels through epithelial cell sheets whose permeability is primarily dependent on the claudin subtype. Recently determined crystal structures of several claudins revealed the unique claudin fold of four transmembrane helices in a left-handed helical bundle with an extracellular β-sheet domain. Here, we focus on the structural basis of the intermolecular interactions between claudin molecules and between the Clostridium perfringens enterotoxin and its receptor claudins.
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Affiliation(s)
- Hiroshi Suzuki
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Chikusa, Nagoya, Japan
| | - Kazutoshi Tani
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Chikusa, Nagoya, Japan
| | - Yoshinori Fujiyoshi
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Chikusa, Nagoya, Japan.,Department of Basic Medical Science, Graduate School of Pharmaceutical Science, Nagoya University, Chikusa, Nagoya, Japan
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