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Oami T, Abtahi S, Shimazui T, Chen CW, Sweat YY, Liang Z, Burd EM, Farris AB, Roland JT, Tsukita S, Ford ML, Turner JR, Coopersmith CM. Claudin-2 upregulation enhances intestinal permeability, immune activation, dysbiosis, and mortality in sepsis. Proc Natl Acad Sci U S A 2024; 121:e2217877121. [PMID: 38412124 DOI: 10.1073/pnas.2217877121] [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: 10/19/2022] [Accepted: 01/16/2024] [Indexed: 02/29/2024] Open
Abstract
Intestinal epithelial expression of the tight junction protein claudin-2, which forms paracellular cation and water channels, is precisely regulated during development and in disease. Here, we show that small intestinal epithelial claudin-2 expression is selectively upregulated in septic patients. Similar changes occurred in septic mice, where claudin-2 upregulation coincided with increased flux across the paracellular pore pathway. In order to define the significance of these changes, sepsis was induced in claudin-2 knockout (KO) and wild-type (WT) mice. Sepsis-induced increases in pore pathway permeability were prevented by claudin-2 KO. Moreover, claudin-2 deletion reduced interleukin-17 production and T cell activation and limited intestinal damage. These effects were associated with reduced numbers of neutrophils, macrophages, dendritic cells, and bacteria within the peritoneal fluid of septic claudin-2 KO mice. Most strikingly, claudin-2 deletion dramatically enhanced survival in sepsis. Finally, the microbial changes induced by sepsis were less pathogenic in claudin-2 KO mice as survival of healthy WT mice injected with cecal slurry collected from WT mice 24 h after sepsis was far worse than that of healthy WT mice injected with cecal slurry collected from claudin-2 KO mice 24 h after sepsis. Claudin-2 upregulation and increased pore pathway permeability are, therefore, key intermediates that contribute to development of dysbiosis, intestinal damage, inflammation, ineffective pathogen control, and increased mortality in sepsis. The striking impact of claudin-2 deletion on progression of the lethal cascade activated during sepsis suggests that claudin-2 may be an attractive therapeutic target in septic patients.
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Affiliation(s)
- Takehiko Oami
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA 30322
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
| | - Shabnam Abtahi
- Laboratory of Mucosal Pathobiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
| | - Takashi Shimazui
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA 30322
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
| | - Ching-Wen Chen
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA 30322
| | - Yan Y Sweat
- Laboratory of Mucosal Pathobiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
| | - Zhe Liang
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA 30322
| | - Eileen M Burd
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Alton B Farris
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Joe T Roland
- Epithelial Biology Center, Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37240
| | - Sachiko Tsukita
- Advanced Comprehensive Research Organization, Teikyo University, Tokyo 173-0003, Japan
| | - Mandy L Ford
- Department of Surgery and Emory Transplant Center, Emory University School of Medicine, Atlanta, GA 30322
| | - Jerrold R Turner
- Laboratory of Mucosal Pathobiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
| | - Craig M Coopersmith
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA 30322
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2
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Wibbe N, Ebnet K. Cell Adhesion at the Tight Junctions: New Aspects and New Functions. Cells 2023; 12:2701. [PMID: 38067129 PMCID: PMC10706136 DOI: 10.3390/cells12232701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 11/17/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
Tight junctions (TJ) are cell-cell adhesive structures that define the permeability of barrier-forming epithelia and endothelia. In contrast to this seemingly static function, TJs display a surprisingly high molecular complexity and unexpected dynamic regulation, which allows the TJs to maintain a barrier in the presence of physiological forces and in response to perturbations. Cell-cell adhesion receptors play key roles during the dynamic regulation of TJs. They connect individual cells within cellular sheets and link sites of cell-cell contacts to the underlying actin cytoskeleton. Recent findings support the roles of adhesion receptors in transmitting mechanical forces and promoting phase separation. In this review, we discuss the newly discovered functions of cell adhesion receptors localized at the TJs and their role in the regulation of the barrier function.
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Affiliation(s)
- Nicolina Wibbe
- Institute-Associated Research Group "Cell Adhesion and Cell Polarity", Institute of Medical Biochemistry, ZMBE, University of Münster, Von-Esmarch-Str. 56, D-48149 Münster, Germany
| | - Klaus Ebnet
- Institute-Associated Research Group "Cell Adhesion and Cell Polarity", Institute of Medical Biochemistry, ZMBE, University of Münster, Von-Esmarch-Str. 56, D-48149 Münster, Germany
- Cells-in-Motion Cluster of Excellence (EXC 1003-CiM), University of Münster, D-48419 Münster, Germany
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3
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Abstract
Sequential expression of claudins, a family of tight junction proteins, along the nephron mirrors the sequential expression of ion channels and transporters. Only by the interplay of transcellular and paracellular transport can the kidney efficiently maintain electrolyte and water homeostasis in an organism. Although channel and transporter defects have long been known to perturb homeostasis, the contribution of individual tight junction proteins has been less clear. Over the past two decades, the regulation and dysregulation of claudins have been intensively studied in the gastrointestinal tract. Claudin expression patterns have, for instance, been found to be affected in infection and inflammation, or in cancer. In the kidney, a deeper understanding of the causes as well as the effects of claudin expression alterations is only just emerging. Little is known about hormonal control of the paracellular pathway along the nephron, effects of cytokines on renal claudin expression or relevance of changes in paracellular permeability to the outcome in any of the major kidney diseases. By summarizing current findings on the role of specific claudins in maintaining electrolyte and water homeostasis, this Review aims to stimulate investigations on claudins as prognostic markers or as druggable targets in kidney disease.
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Affiliation(s)
- Luca Meoli
- Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Dorothee Günzel
- Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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4
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Berselli A, Alberini G, Benfenati F, Maragliano L. The impact of pathogenic and artificial mutations on Claudin-5 selectivity from molecular dynamics simulations. Comput Struct Biotechnol J 2023; 21:2640-2653. [PMID: 37138900 PMCID: PMC10149405 DOI: 10.1016/j.csbj.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/03/2023] [Accepted: 04/03/2023] [Indexed: 05/05/2023] Open
Abstract
Tight-junctions (TJs) are multi-protein complexes between adjacent endothelial or epithelial cells. In the blood-brain-barrier (BBB), they seal the paracellular space and the Claudin-5 (Cldn5) protein forms their backbone. Despite the fundamental role in brain homeostasis, little is known on Cldn5-based TJ assemblies. Different structural models were suggested, with Cldn5 protomers generating paracellular pores that restrict the passage of ions and small molecules. Recently, the first Cldn5 pathogenic mutation, G60R, was identified and shown to induce Cl--selective channels and Na+ barriers in BBB TJs, providing an excellent opportunity to validate the structural models. Here, we used molecular dynamics to study the permeation of ions and water through two distinct G60R-Cldn5 paracellular architectures. Only the so-called Pore I reproduces the functional modification observed in experiments, displaying a free energy (FE) minimum for Cl- and a barrier for Na+ consistent with anionic selectivity. We also studied the artificial Q57D and Q63D mutations in the constriction region, Q57 being conserved in Cldns except for cation permeable homologs. In both cases, we obtain FE profiles consistent with facilitated passage of cations. Our calculations provide the first in-silico description of a Cldn5 pathogenic mutation, further assessing the TJ Pore I model and yielding new insight on BBB's paracellular selectivity.
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Affiliation(s)
- Alessandro Berselli
- Center for Synaptic Neuroscience and Technology (NSYN@UniGe), Istituto Italiano di Tecnologia, Largo Rosanna Benzi, 10, 16132 Genova, Italy
- Department of Experimental Medicine, Università degli Studi di Genova, Viale Benedetto XV, 3, 16132, Genova, Italy
| | - Giulio Alberini
- Center for Synaptic Neuroscience and Technology (NSYN@UniGe), Istituto Italiano di Tecnologia, Largo Rosanna Benzi, 10, 16132 Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi, 10, 16132, Genova, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology (NSYN@UniGe), Istituto Italiano di Tecnologia, Largo Rosanna Benzi, 10, 16132 Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi, 10, 16132, Genova, Italy
- Corresponding authors at: Center for Synaptic Neuroscience and Technology (NSYN@UniGe), Istituto Italiano di Tecnologia, Largo Rosanna Benzi, 10, 16132 Genova, Italy.
| | - Luca Maragliano
- Center for Synaptic Neuroscience and Technology (NSYN@UniGe), Istituto Italiano di Tecnologia, Largo Rosanna Benzi, 10, 16132 Genova, Italy
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131, Ancona, Italy
- Corresponding authors at: Center for Synaptic Neuroscience and Technology (NSYN@UniGe), Istituto Italiano di Tecnologia, Largo Rosanna Benzi, 10, 16132 Genova, Italy.
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5
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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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6
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Jackson V, Hermann J, Tynan CJ, Rolfe DJ, Corey RA, Duncan AL, Noriega M, Chu A, Kalli AC, Jones EY, Sansom MSP, Martin-Fernandez ML, Seiradake E, Chavent M. The guidance and adhesion protein FLRT2 dimerizes in cis via dual small-X 3-small transmembrane motifs. Structure 2022; 30:1354-1365.e5. [PMID: 35700726 DOI: 10.1016/j.str.2022.05.014] [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: 08/02/2021] [Revised: 03/03/2022] [Accepted: 05/18/2022] [Indexed: 10/18/2022]
Abstract
Fibronectin Leucine-rich Repeat Transmembrane (FLRT 1-3) proteins are a family of broadly expressed single-spanning transmembrane receptors that play key roles in development. Their extracellular domains mediate homotypic cell-cell adhesion and heterotypic protein interactions with other receptors to regulate cell adhesion and guidance. These in trans FLRT interactions determine the formation of signaling complexes of varying complexity and function. Whether FLRTs also interact at the surface of the same cell, in cis, remains unknown. Here, molecular dynamics simulations reveal two dimerization motifs in the FLRT2 transmembrane helix. Single particle tracking experiments show that these Small-X3-Small motifs synergize with a third dimerization motif encoded in the extracellular domain to permit the cis association and co-diffusion patterns of FLRT2 receptors on cells. These results may point to a competitive switching mechanism between in cis and in trans interactions, which suggests that homotypic FLRT interaction mirrors the functionalities of classic adhesion molecules.
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Affiliation(s)
- Verity Jackson
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK
| | - Julia Hermann
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK
| | - Christopher J Tynan
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Harwell Campus, Didcot, OX11 0FA, UK
| | - Daniel J Rolfe
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Harwell Campus, Didcot, OX11 0FA, UK
| | - Robin A Corey
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK
| | - Anna L Duncan
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK
| | - Maxime Noriega
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, 31400 Toulouse, France
| | - Amy Chu
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK
| | - Antreas C Kalli
- Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine and Astbury Center for Structural Molecular Biology, University of Leeds, Leeds, LS2 9NL, UK
| | - E Yvonne Jones
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK
| | - Marisa L Martin-Fernandez
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Harwell Campus, Didcot, OX11 0FA, UK.
| | - Elena Seiradake
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK.
| | - Matthieu Chavent
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, 31400 Toulouse, France.
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7
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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] [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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8
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Marrink SJ, Monticelli L, Melo MN, Alessandri R, Tieleman DP, Souza PCT. Two decades of Martini: Better beads, broader scope. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2022. [DOI: 10.1002/wcms.1620] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Siewert J. Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials University of Groningen Groningen The Netherlands
| | - Luca Monticelli
- Molecular Microbiology and Structural Biochemistry (MMSB ‐ UMR 5086) CNRS & University of Lyon Lyon France
| | - Manuel N. Melo
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras Portugal
| | - Riccardo Alessandri
- Pritzker School of Molecular Engineering University of Chicago Chicago Illinois USA
| | - D. Peter Tieleman
- Centre for Molecular Simulation and Department of Biological Sciences University of Calgary Alberta Canada
| | - Paulo C. T. Souza
- Molecular Microbiology and Structural Biochemistry (MMSB ‐ UMR 5086) CNRS & University of Lyon Lyon France
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9
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Guo W, Zou X, Jiang H, Koebke KJ, Hoarau M, Crisci R, Lu T, Wei T, Marsh ENG, Chen Z. Molecular Structure of the Surface-Immobilized Super Uranyl Binding Protein. J Phys Chem B 2021; 125:7706-7716. [PMID: 34254804 DOI: 10.1021/acs.jpcb.1c03849] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Recently, a super uranyl binding protein (SUP) was developed, which exhibits excellent sensitivity/selectivity to bind uranyl ions. It can be immobilized onto a surface in sensing devices to detect uranyl ions. Here, sum frequency generation (SFG) vibrational spectroscopy was applied to probe the interfacial structures of surface-immobilized SUP. The collected SFG spectra were compared to the calculated orientation-dependent SUP SFG spectra using a one-excitonic Hamiltonian approach based on the SUP crystal structures to deduce the most likely surface-immobilized SUP orientation(s). Furthermore, discrete molecular dynamics (DMD) simulation was applied to refine the surface-immobilized SUP conformations and orientations. The immobilized SUP structures calculated from DMD simulations confirmed the SUP orientations obtained from SFG data analyzed based on the crystal structures and were then used for a new round of SFG orientation analysis to more accurately determine the interfacial orientations and conformations of immobilized SUP before and after uranyl ion binding, providing an in-depth understanding of molecular interactions between SUP and the surface and the effect of uranyl ion binding on the SUP interfacial structures. We believe that the developed method of combining SFG measurements, DMD simulation, and Hamiltonian data analysis approach is widely applicable to study biomolecules at solid/liquid interfaces.
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Affiliation(s)
- Wen Guo
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Xingquan Zou
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Hanjie Jiang
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Karl J Koebke
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Marie Hoarau
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Ralph Crisci
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Tieyi Lu
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Tao Wei
- Department of Chemical Engineering, Howard University, 2366 Sixth Street, NW, Washington, D.C. 20059, United States
| | - E Neil G Marsh
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Zhan Chen
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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10
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Yee SM, Gillams RJ, McLain SE, Lorenz CD. Effects of lipid heterogeneity on model human brain lipid membranes. SOFT MATTER 2021; 17:126-135. [PMID: 33155582 DOI: 10.1039/d0sm01766c] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Cell membranes naturally contain a heterogeneous lipid distribution. However, homogeneous bilayers are commonly preferred and utilised in computer simulations due to their relative simplicity, and the availability of lipid force field parameters. Recently, experimental lipidomics data for the human brain cell membranes under healthy and Alzheimer's disease (AD) conditions were investigated, since disruption to the lipid composition has been implicated in neurodegenerative disorders, including AD [R. B. Chan et al., J. Biol. Chem., 2012, 287, 2678-2688]. In order to observe the effects of lipid complexity on the various bilayer properties, molecular dynamics simulations were used to study four membranes with increasing heterogeneity: a pure POPC membrane, a POPC and cholesterol membrane in a 1 : 1 ratio (POPC-CHOL), and to our knowledge, the first realistic models of a healthy brain membrane and an Alzheimer's diseased brain membrane. Numerous structural, interfacial, and dynamical properties, including the area per lipid, interdigitation, dipole potential, and lateral diffusion of the two simple models, POPC and POPC-CHOL, were analysed and compared to those of the complex brain models consisting of 27 lipid components. As the membranes gain heterogeneity, a number of alterations were found in the structural and dynamical properties, and more significant differences were observed in the lateral diffusion. Additionally, we observed snorkeling behaviour of the lipid tails that may play a role in the permeation of small molecules across biological membranes. In this work, atomistic description of realistic brain membrane models is provided, which can add insight towards the permeability and transport pathways of small molecules across these membrane barriers.
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Affiliation(s)
- Sze May Yee
- Department of Physics, King's College London, London WC2R 2LS, UK.
| | - Richard J Gillams
- School of Electronics and Computer Science, and Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Sylvia E McLain
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9RH, UK
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11
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Post-translational modifications of tight junction transmembrane proteins and their direct effect on barrier function. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183330. [PMID: 32376223 DOI: 10.1016/j.bbamem.2020.183330] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 04/21/2020] [Accepted: 04/27/2020] [Indexed: 12/24/2022]
Abstract
Post-translational modifications (PTMs) such as phosphorylation, ubiquitination or glycosylation are processes affecting the conformation, stability, localization and function of proteins. There is clear evidence that PTMs can act upon tight junction (TJ) proteins, thus modulating epithelial barrier function. Compared to transcriptional or translational regulation, PTMs are rapid and more dynamic processes so in the context of barrier maintenance they might be essential for coping with changing environmental or external impacts. The aim of this review is to extract literature deciphering PTMs in TJ proteins directly contributing to epithelial barrier changes in permeability to ions and macromolecules. It is not intended to cover the entire scope of PTMs in TJ proteins and should rather be understood as a digest of TJ protein modifications directly resulting in the tightening or opening of the epithelial barrier.
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12
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Zimmer SE, Kowalczyk AP. The desmosome as a model for lipid raft driven membrane domain organization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183329. [PMID: 32376221 DOI: 10.1016/j.bbamem.2020.183329] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 04/20/2020] [Accepted: 04/23/2020] [Indexed: 01/14/2023]
Abstract
Desmosomes are cadherin-based adhesion structures that mechanically couple the intermediate filament cytoskeleton of adjacent cells to confer mechanical stress resistance to tissues. We have recently described desmosomes as mesoscale lipid raft membrane domains that depend on raft dynamics for assembly, function, and disassembly. Lipid raft microdomains are regions of the plasma membrane enriched in sphingolipids and cholesterol. These domains participate in membrane domain heterogeneity, signaling and membrane trafficking. Cellular structures known to be dependent on raft dynamics include the post-synaptic density in neurons, the immunological synapse, and intercellular junctions, including desmosomes. In this review, we discuss the current state of the desmosome field and put forward new hypotheses for the role of lipid rafts in desmosome adhesion, signaling and epidermal homeostasis. Furthermore, we propose that differential lipid raft affinity of intercellular junction proteins is a central driving force in the organization of the epithelial apical junctional complex.
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Affiliation(s)
- Stephanie E Zimmer
- Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University, Atlanta, GA 30322, United States of America; Department of Cell Biology, Emory University, Atlanta, GA 30322, United States of America
| | - Andrew P Kowalczyk
- Department of Cell Biology, Emory University, Atlanta, GA 30322, United States of America; Department of Dermatology, Emory University, Atlanta, GA 30322, United States of America.
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13
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Oda Y, Sugawara T, Fukata Y, Izumi Y, Otani T, Higashi T, Fukata M, Furuse M. The extracellular domain of angulin-1 and palmitoylation of its cytoplasmic region are required for angulin-1 assembly at tricellular contacts. J Biol Chem 2020; 295:4289-4302. [PMID: 32079676 PMCID: PMC7105312 DOI: 10.1074/jbc.ra119.010491] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 02/13/2020] [Indexed: 12/13/2022] Open
Abstract
Tricellular tight junctions (tTJs) create paracellular barriers at tricellular contacts (TCs), where the vertices of three polygonal epithelial cells meet. tTJs are marked by the enrichment of two types of membrane proteins, tricellulin and angulin family proteins. However, how TC geometry is recognized for tTJ formation remains unknown. In the present study, we examined the molecular mechanism for the assembly of angulin-1 at the TCs. We found that clusters of cysteine residues in the juxtamembrane region within the cytoplasmic domain of angulin-1 are highly palmitoylated. Mutagenesis analyses of the cysteine residues in this region revealed that palmitoylation is essential for localization of angulin-1 at TCs. Consistently, suppression of Asp-His-His-Cys motif-containing palmitoyltransferases expressed in EpH4 cells significantly impaired the TC localization of angulin-1. Cholesterol depletion from the plasma membrane of cultured epithelial cells hampered the localization of angulin-1 at TCs, suggesting the existence of a lipid membrane microdomain at TCs that attracts highly palmitoylated angulin-1. Furthermore, the extracellular domain of angulin-1 was also required for its TC localization, irrespective of the intracellular palmitoylation. Taken together, our findings suggest that both angulin-1's extracellular domain and palmitoylation of its cytoplasmic region are required for its assembly at TCs.
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Affiliation(s)
- Yukako Oda
- Division of Cell Biology, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
| | - Taichi Sugawara
- Division of Cell Structure, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Yuko Fukata
- Department of Physiological Sciences, School of Life Science, Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan; Division of Membrane Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Yasushi Izumi
- Division of Cell Structure, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Tetsuhisa Otani
- Division of Cell Structure, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Tomohito Higashi
- Division of Cell Biology, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
| | - Masaki Fukata
- Department of Physiological Sciences, School of Life Science, Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan; Division of Membrane Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Mikio Furuse
- Division of Cell Biology, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan; Division of Cell Structure, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan.
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14
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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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15
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Role of Claudin Proteins in Regulating Cancer Stem Cells and Chemoresistance-Potential Implication in Disease Prognosis and Therapy. Int J Mol Sci 2019; 21:ijms21010053. [PMID: 31861759 PMCID: PMC6982342 DOI: 10.3390/ijms21010053] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/11/2019] [Accepted: 12/13/2019] [Indexed: 12/11/2022] Open
Abstract
Claudins are cell–cell adhesion proteins, which are expressed in tight junctions (TJs), the most common apical cell-cell adhesion. Claudin proteins help to regulate defense and barrier functions, as well as differentiation and polarity in epithelial and endothelial cells. A series of studies have now reported dysregulation of claudin proteins in cancers. However, the precise mechanisms are still not well understood. Nonetheless, studies have clearly demonstrated a causal role of multiple claudins in the regulation of epithelial to mesenchymal transition (EMT), a key feature in the acquisition of a cancer stem cell phenotype in cancer cells. In addition, claudin proteins are known to modulate therapy resistance in cancer cells, a feature associated with cancer stem cells. In this review, we have focused primarily on highlighting the causal link between claudins, cancer stem cells, and therapy resistance. We have also contemplated the significance of claudins as novel targets in improving the efficacy of cancer therapy. Overall, this review provides a much-needed understanding of the emerging role of claudin proteins in cancer malignancy and therapeutic management.
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16
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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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17
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Rajagopal N, Nangia S. Obtaining Protein Association Energy Landscape for Integral Membrane Proteins. J Chem Theory Comput 2019; 15:6444-6455. [DOI: 10.1021/acs.jctc.9b00626] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Nandhini Rajagopal
- Department of Biomedical and Chemical Engineering, Syracuse University, 343 Link Hall, Syracuse, New York 13244, United States
| | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, 343 Link Hall, Syracuse, New York 13244, United States
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18
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Campaña MB, Irudayanathan FJ, Davis TR, McGovern-Gooch KR, Loftus R, Ashkar M, Escoffery N, Navarro M, Sieburg MA, Nangia S, Hougland JL. The ghrelin O-acyltransferase structure reveals a catalytic channel for transmembrane hormone acylation. J Biol Chem 2019; 294:14166-14174. [PMID: 31413115 DOI: 10.1074/jbc.ac119.009749] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 08/12/2019] [Indexed: 01/17/2023] Open
Abstract
Integral membrane proteins represent a large and diverse portion of the proteome and are often recalcitrant to purification, impeding studies essential for understanding protein structure and function. By combining co-evolutionary constraints and computational modeling with biochemical validation through site-directed mutagenesis and enzyme activity assays, we demonstrate here a synergistic approach to structurally model purification-resistant topologically complex integral membrane proteins. We report the first structural model of a eukaryotic membrane-bound O-acyltransferase (MBOAT), ghrelin O-acyltransferase (GOAT), which modifies the metabolism-regulating hormone ghrelin. Our structure, generated in the absence of any experimental structural data, revealed an unanticipated strategy for transmembrane protein acylation with catalysis occurring in an internal channel connecting the endoplasmic reticulum lumen and cytoplasm. This finding validated the power of our approach to generate predictive structural models for other experimentally challenging integral membrane proteins. Our results illuminate novel aspects of membrane protein function and represent key steps for advancing structure-guided inhibitor design to target therapeutically important but experimentally intractable membrane proteins.
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Affiliation(s)
- Maria B Campaña
- Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | | | - Tasha R Davis
- Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | | | - Rosemary Loftus
- Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | - Mohammad Ashkar
- Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | - Najae Escoffery
- Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | - Melissa Navarro
- Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | | | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244 .,Syracuse Biomaterials Institute, Syracuse University, Syracuse, New York 13244
| | - James L Hougland
- Department of Chemistry, Syracuse University, Syracuse, New York 13244 .,Syracuse Biomaterials Institute, Syracuse University, Syracuse, New York 13244
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19
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Jiang L, Li S, Zheng J, Li Y, Huang H. Recent Progress in Microfluidic Models of the Blood-Brain Barrier. MICROMACHINES 2019; 10:mi10060375. [PMID: 31195652 PMCID: PMC6630552 DOI: 10.3390/mi10060375] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 05/29/2019] [Accepted: 06/02/2019] [Indexed: 02/07/2023]
Abstract
The blood-brain barrier (BBB) is a critical physical and chemical barrier that maintains brain homeostasis. Researchers in academia and industry are highly motivated to develop experimental models that can accurately mimic the physiological characteristics of the BBB. Microfluidic systems, which manipulate fluids at the micrometer scale, are ideal tools for simulating the BBB microenvironment. In this review, we summarized the progress in the design and evaluation of microfluidic in vitro BBB models, including advances in chip materials, porous membranes, the use of endothelial cells, the importance of shear stress, the detection specific markers to monitor tight junction formation and integrity, measurements of TEER and permeability. We also pointed out several shortcomings of the current microfluidic models. The purpose of this paper is to let the readers understand the characteristics of different types of model design, and select appropriate design parameters according to the research needs, so as to obtain the best experimental results. We believe that the microfluidics BBB models will play an important role in neuroscience and pharmaceutical research.
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Affiliation(s)
- Lili Jiang
- Department of Clinical and Military Laboratory Medicine, Army Medical University, Chongqing 400038, China.
| | - Shu Li
- Department of Microbiology, Army Medical University, Chongqing 400038, China.
| | - Junsong Zheng
- Department of Clinical and Military Laboratory Medicine, Army Medical University, Chongqing 400038, China.
| | - Yan Li
- Department of Clinical and Military Laboratory Medicine, Army Medical University, Chongqing 400038, China.
| | - Hui Huang
- Department of Clinical and Military Laboratory Medicine, Army Medical University, Chongqing 400038, China.
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