Epithelial self-healing is recapitulated by a 3D biomimetic E-cadherin junction

Epithelial monolayers undergo self-healing when wounded. During healing, cells collectively migrate into the wound site, and the converging tissue fronts collide and form a stable interface. To heal, migrating tissues must form cell–cell adhesions and reorganize from the front-rear polarity characteristic of cell migration to the apical-basal polarity of an epithelium. However, identifying the "stop signal" that induces colliding tissues to cease migrating and heal remains an open question. Epithelial cells form integrin-based adhesions to the basal extracellular matrix (ECM) and E-cadherin–mediated cell–cell adhesions on the orthogonal, lateral surfaces between cells. Current biological tools have been unable to probe this multicellular 3D interface to determine the stop signal. We addressed this problem by developing a unique biointerface that mimicked the 3D organization of epithelial cell adhesions. This "minimal tissue mimic" (MTM) comprised a basal ECM substrate and a vertical surface coated with purified extracellular domain of E-cadherin, and was designed for collision with the healing edge of an epithelial monolayer. Three-dimensional imaging showed that adhesions formed between cells, and the E-cadherin-coated MTM resembled the morphology and dynamics of native epithelial cell–cell junctions and induced the same polarity transition that occurs during epithelial self-healing. These results indicate that E-cadherin presented in the proper 3D context constitutes a minimum essential stop signal to induce self-healing. That the Ecad:Fc MTM stably integrated into an epithelial tissue and reduced migration at the interface suggests that this biointerface is a complimentary approach to existing tissue–material interfaces.

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Formin-mediated actin polymerization at cell–cell junctions stabilizes E-cadherin and maintains monolayer integrity during wound repair

Molecular Biology of the Cell ◽

10.1091/mbc.e16-06-0429 ◽

2016 ◽

Vol 27 (18) ◽

pp. 2844-2856 ◽

Cited By ~ 31

Author(s):

Megha Vaman Rao ◽

Ronen Zaidel-Bar

Keyword(s):

Cell Adhesion ◽

Wound Repair ◽

Actin Polymerization ◽

Cell Junctions ◽

Epithelial Tissue ◽

Collective Cell Migration ◽

Epithelial Junctions ◽

Major Factors ◽

E Cadherin ◽

Cell Cell

Cadherin-mediated cell–cell adhesion is required for epithelial tissue integrity in homeostasis, during development, and in tissue repair. E-cadherin stability depends on F-actin, but the mechanisms regulating actin polymerization at cell–cell junctions remain poorly understood. Here we investigated a role for formin-mediated actin polymerization at cell–cell junctions. We identify mDia1 and Fmnl3 as major factors enhancing actin polymerization and stabilizing E-cadherin at epithelial junctions. Fmnl3 localizes to adherens junctions downstream of Src and Cdc42 and its depletion leads to a reduction in F-actin and E-cadherin at junctions and a weakening of cell–cell adhesion. Of importance, Fmnl3 expression is up-regulated and junctional localization increases during collective cell migration. Depletion of Fmnl3 or mDia1 in migrating monolayers results in dissociation of leader cells and impaired wound repair. In summary, our results show that formin activity at epithelial cell–cell junctions is important for adhesion and the maintenance of epithelial cohesion during dynamic processes, such as wound repair.

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Analysis of E-Cadherin as a Tension Sensor at Epithelial Cell-Cell Junctions

Biophysical Journal ◽

10.1016/j.bpj.2011.11.3818 ◽

2012 ◽

Vol 102 (3) ◽

pp. 703a

Author(s):

Mariya N. Sorokina ◽

Nicolas Borghi ◽

Olga Shcherbakova ◽

James Nelson ◽

Alexander Dunn

Keyword(s):

Epithelial Cell ◽

Cell Junctions ◽

Tension Sensor ◽

E Cadherin ◽

Cell Cell

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DISTINCT ACTIN-DEPENDENT NANOSCALE ASSEMBLIES UNDERLIE THE DYNAMIC AND HIERARCHICAL ORGANIZATION OF E-CADHERIN

10.1101/851899 ◽

2019 ◽

Author(s):

Rumamol Chandran ◽

Girish Kale ◽

Jean-Marc Philippe ◽

Thomas Lecuit ◽

Satyajit Mayor

Keyword(s):

Ectopic Expression ◽

Fluorescence Emission ◽

Correlation Spectroscopy ◽

Hierarchical Organization ◽

Cell Junctions ◽

Epithelial Tissue ◽

Emission Anisotropy ◽

Dynamic Organization ◽

E Cadherin ◽

Cell Cell

SUMMARYIntercellular adhesion mediated by E-cadherin is pivotal in maintaining epithelial tissue integrity and for tissue morphogenesis. Adhesion requires homophilic interactions between extracellular domains of E-cadherin molecules from neighboring cells. The interaction of its cytoplasmic domains with the cortical acto-myosin network, appears to strengthen adhesion, although, it is unclear how cortical actin affects the organization and function of E-cadherin dynamically. Here we use the ectopic expression of Drosophila E-cadherin (E-cad) in larval hemocytes, which lack endogenous E-cad, to recapitulate functional cell-cell junctions in a convenient model system. We used fluorescence emission anisotropy-based microscopy and Fluorescence Correlation Spectroscopy (FCS) to probe the nanoscale organization of E-cad. We find that E-cad at cell-cell junctions in hemocytes exhibits a clustered trans-paired organization, similar to that reported for the adherens junction in the developing embryonic epithelial tissue. Further, we find that extra-junctional E-cad is also organized as relatively immobile nanoclusters as well as diffusive and more loosely packed oligomers and monomers. These oligomers are promoted by cis-interactions of the ectodomain and, strikingly, their growth is constantly counteracted by cortical actomyosin. Oligomers in turn assist in generating nanoclusters that are stabilized by cortical acto-myosin. Thus, actin remodels oligomers and stabilizes nanoclusters, revealing a requirement for actin in the dynamic organization of E-cad at the nanoscale. This dynamic organization is also present at cell-cell contacts (junction), and its disruption affects junctional integrity in the hemocyte system, as well as in the embryo. Our observations uncover a hierarchical mechanism for the nanoscale organization of E-cad, which is necessary for dynamic adhesion and maintaining junctional integrity in the face of extensive remodeling.

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Characterization of Porphyromonas gingivalis-Induced Degradation of Epithelial Cell Junctional Complexes

Infection and Immunity ◽

10.1128/iai.68.3.1441-1449.2000 ◽

2000 ◽

Vol 68 (3) ◽

pp. 1441-1449 ◽

Cited By ~ 135

Author(s):

Jannet Katz ◽

Vijaya Sambandam ◽

John H. Wu ◽

Suzanne M. Michalek ◽

Daniel F. Balkovetz

Keyword(s):

Epithelial Cell ◽

Mdck Cell ◽

Mdck Cells ◽

Transmembrane Proteins ◽

Cell Junctions ◽

Epithelial Barrier ◽

Β1 Integrin ◽

E Cadherin ◽

Cell Cell

ABSTRACT Porphyromonas gingivalis is considered among the etiological agents of human adult periodontitis. Although in vitro studies have shown that P. gingivalis has the ability to invade epithelial cell lines, its effect on the epithelial barrier junctions is not known. Immunofluorescence analysis of human gingival epithelial cells confirmed the presence of tight-junction (occludin), adherens junction (E-cadherin), and cell-extracellular matrix junction (β1-integrin) transmembrane proteins. These transmembrane proteins are expressed in Madin-Darby canine kidney (MDCK) cells. In addition, MDCK cells polarize and therefore serve as a useful in vitro model for studies on the epithelial cell barrier. Using the MDCK cell system, we examined the effect of P. gingivalis on epithelial barrier function. Exposure of the basolateral surfaces of MDCK cells to P. gingivalis (>109 bacteria/ml) resulted in a decrease in transepithelial resistance. Immunofluorescence microscopy demonstrated decreases in the amounts of immunoreactive occludin, E-cadherin, and β1-integrin at specific times which were related to a disruption of cell-cell junctions in MDCK cells exposed to basolateralP. gingivalis. Disruption of cell-cell junctions was also observed upon apical exposure to bacteria; however, the effects took longer than those seen upon basolateral exposure. Cell viability was not affected by either basolateral or apical exposure to P. gingivalis. Western blot analysis demonstrated hydrolysis of occludin, E-cadherin, and β1-integrin in lysates derived from MDCK cells exposed to P. gingivalis. Immunoprecipitated occludin and E-cadherin molecules from MDCK cell lysates were also degraded by P. gingivalis, suggesting a bacterial protease(s) capable of cleaving these epithelial junction transmembrane proteins. Collectively, these data suggest thatP. gingivalis is able to invade the deeper structures of connective tissues via a paracellular pathway by degrading epithelial cell-cell junction complexes, thus allowing the spread of the bacterium. These results also indicate the importance of a critical threshold concentration of P. gingivalis to initiate epithelial barrier destruction.

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(Tissue) P systems with cell polarity

Mathematical Structures in Computer Science ◽

10.1017/s0960129509990156 ◽

2009 ◽

Vol 19 (6) ◽

pp. 1141-1160 ◽

Cited By ~ 2

Author(s):

DANIELA BESOZZI ◽

NADIA BUSI ◽

PAOLO CAZZANIGA ◽

CLAUDIO FERRETTI ◽

ALBERTO LEPORATI ◽

...

Keyword(s):

Cell Polarity ◽

Formal System ◽

Cell Junctions ◽

P Systems ◽

Intestinal Lumen ◽

Epithelial Tissue ◽

Specific Cell ◽

Formal Property ◽

Intestinal Epithelial ◽

Cell Cell

We consider the structure of the intestinal epithelial tissue and of cell–cell junctions as the biological model inspiring a new class of P systems. First we define the concept of cell polarity, a formal property derived from epithelial cells, which present morphologically and functionally distinct regions of the plasma membrane. Then we show two preliminary results for this new model of computation: on the theoretical side, we show that P systems with cell polarity are computationally (Turing) complete; on the modelling side, we show that the transepithelial movement of glucose from the intestinal lumen into the blood can be described by such a formal system. Finally, we define tissue P systems with cell polarity, where each cell has fixed connections to the neighbouring cells and to the environment, according to both the cell polarity and specific cell–cell junctions.

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Remodeling the cell surface distribution of membrane proteins during the development of epithelial cell polarity.

The Journal of Cell Biology ◽

10.1083/jcb.116.4.889 ◽

1992 ◽

Vol 116 (4) ◽

pp. 889-899 ◽

Cited By ~ 60

Author(s):

D A Wollner ◽

K A Krzeminski ◽

W J Nelson

Keyword(s):

Epithelial Cell ◽

Membrane Proteins ◽

Cell Surface ◽

Mdck Cells ◽

Apical Cell ◽

Cell Contact ◽

Surface Polarity ◽

Lateral Membrane ◽

E Cadherin ◽

Cell Cell

The development of polarized epithelial cells from unpolarized precursor cells follows induction of cell-cell contacts and requires resorting of proteins into different membrane domains. We show that in MDCK cells the distributions of two membrane proteins, Dg-1 and E-cadherin, become restricted to the basal-lateral membrane domain within 8 h of cell-cell contact. During this time, however, 60-80% of newly synthesized Dg-1 and E-cadherin is delivered directly to the forming apical membrane and then rapidly removed, while the remainder is delivered to the basal-lateral membrane and has a longer residence time. Direct delivery of greater than 95% of these proteins from the Golgi complex to the basal-lateral membrane occurs greater than 48 h later. In contrast, we show that two apical proteins are efficiently delivered and restricted to the apical cell surface within 2 h after cell-cell contact. These results provide insight into mechanisms involved in the development of epithelial cell surface polarity, and the establishment of protein sorting pathways in polarized cells.

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A molecular mechanism directly linking E-cadherin adhesion to initiation of epithelial cell surface polarity

The Journal of Cell Biology ◽

10.1083/jcb.200705094 ◽

2007 ◽

Vol 178 (2) ◽

pp. 323-335 ◽

Cited By ~ 109

Author(s):

Lene N. Nejsum ◽

W. James Nelson

Keyword(s):

Cell Adhesion ◽

Epithelial Cell ◽

Cell Surface ◽

Basolateral Membrane ◽

Surface Polarity ◽

Cell Contacts ◽

Protein Receptors ◽

Epithelial Cell Surface ◽

E Cadherin ◽

Cell Cell

Mechanisms involved in maintaining plasma membrane domains in fully polarized epithelial cells are known, but when and how directed protein sorting and trafficking occur to initiate cell surface polarity are not. We tested whether establishment of the basolateral membrane domain and E-cadherin–mediated epithelial cell–cell adhesion are mechanistically linked. We show that the basolateral membrane aquaporin (AQP)-3, but not the equivalent apical membrane AQP5, is delivered in post-Golgi structures directly to forming cell–cell contacts where it co-accumulates precisely with E-cadherin. Functional disruption of individual components of a putative lateral targeting patch (e.g., microtubules, the exocyst, and soluble N-ethylmaleimide–sensitive factor attachment protein receptors) did not inhibit cell–cell adhesion or colocalization of the other components with E-cadherin, but each blocked AQP3 delivery to forming cell–cell contacts. Thus, components of the lateral targeting patch localize independently of each other to cell–cell contacts but collectively function as a holocomplex to specify basolateral vesicle delivery to nascent cell–cell contacts and immediately initiate cell surface polarity.

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HGF Converts ErbB2/Neu Epithelial Morphogenesis to Cell Invasion

Molecular Biology of the Cell ◽

10.1091/mbc.e04-07-0567 ◽

2005 ◽

Vol 16 (2) ◽

pp. 550-561 ◽

Cited By ~ 77

Author(s):

Hanane Khoury ◽

Monica A. Naujokas ◽

Dongmei Zuo ◽

Veena Sangwan ◽

Melanie M. Frigault ◽

...

Keyword(s):

Growth Factor ◽

Hepatocyte Growth Factor ◽

Cell Invasion ◽

Single Cells ◽

Epithelial Morphogenesis ◽

Cell Junctions ◽

Junction Protein ◽

Hepatocyte Growth ◽

E Cadherin ◽

Cell Cell

Activation of the hepatocyte growth factor receptor Met induces a morphogenic response and stimulates the formation of branching tubules by Madin-Darby canine kidney (MDCK) epithelial cells in three-dimensional cultures. A constitutively activated ErbB2/Neu receptor, NeuNT, promotes a similar invasive morphogenic program in MDCK cells. Because both receptors are expressed in breast epithelia, are associated with poor prognosis, and hepatocyte growth factor (HGF) is expressed in stroma, we examined the consequence of cooperation between these signals. We show that HGF disrupts NeuNT-induced epithelial morphogenesis, stimulating the breakdown of cell-cell junctions, dispersal, and invasion of single cells. This correlates with a decrease in junctional proteins claudin-1 and E-cadherin, in addition to the internalization of the tight junction protein ZO-1. HGF-induced invasion of NT-expressing cells is abrogated by pretreatment with a pharmacological inhibitor of the mitogen-activated protein kinase kinase (MEK) pathway, which restores E-cadherin and ZO-1 at cell-cell junctions, establishing the involvement of MEK-dependent pathways in this process. These results demonstrate that physiological signals downstream from the HGF/Met receptor synergize with ErbB2/Neu to enhance the malignant phenotype, promoting the breakdown of cell-cell junctions and enhanced cell invasion. This is particularly important for cancers where ErbB2/Neu is overexpressed and HGF is a physiological growth factor found in the stroma.

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Cortical Tension Initiates the Positive Feedback Loop Between E-cadherin and F-actin

10.1101/2021.02.23.432578 ◽

2021 ◽

Author(s):

Qilin Yu ◽

William R. Holmes ◽

Jean P. Thiery ◽

Rodney B. Luwor ◽

Vijay Rajagopal

Keyword(s):

Positive Feedback ◽

Feedback Loop ◽

Adherens Junctions ◽

Force Balance ◽

Intercellular Junction ◽

Cell Junctions ◽

Positive Feedback Loop ◽

Cortical Tension ◽

E Cadherin ◽

Cell Cell

AbstractAdherens junctions (AJs) physically link two cells at their contact interface via extracellular homophilic interactions between cadherin molecules and intracellular connections between cadherins and the actomyosin cortex. Both cadherin and actomyosin cytoskeletal dynamics are reciprocally regulated by mechanical and chemical signals, which subsequently determine the strength of cell-cell adhesions and the emergent organization and stiffness of the tissues they form. However, an understanding of the integrated system is lacking. We present a new mechanistic computational model of intercellular junction maturation in a cell doublet to investigate the mechano-chemical crosstalk that regulates AJ formation and homeostasis. The model couples a 2D lattice-based model of cadherin dynamics with a continuum, reaction-diffusion model of the reorganizing actomyosin network through its regulation by Rho signaling at the intercellular junction. We demonstrate that local immobilization of cadherin induces cluster formation in a cis less dependent manner. We further investigate how cadherin and actin regulate and cooperate. By considering the force balance during AJ maturation and the force-sensitive property of the cadherin/F-actin linking molecules, we show that cortical tension applied on the contact rim can explain the ring distribution of cadherin and F-actin on the cell-cell contact of the cell-doublet. Meanwhile, the positive feedback loop between cadherin and F-actin is necessary for maintenance of the ring. Different patterns of cadherin distribution can be observed as an emergent property of disturbances of this feedback loop. We discuss these findings in light of available experimental observations on underlying mechanisms related to cadherin/F-actin binding and the mechanical environment.Significance StatementThe formation, maintenance and disassembly of adherens junctions (AJs) is fundamental to organ development, tissue integrity as well as tissue function. E-cadherins and F-actin are two major players of the adherens junctions (AJs). Although it is well known that cadherins and F-actin affect each other, how these two players work together to maintain the intercellular contact is unclear. Using a novel mechano-chemical model of E-cadherin and F-actin remodeling, we demonstrate that a positive feedback loop between cadherins and F-actin allows them to stabilize each other locally. Mechanical and chemical stimuli applied to the cell adhesion change E-cadherin and F-actin distribution by consolidating or interrupting the feedback loop locally. Our study mechanistically links mechanical force to E-cadherin patterning at cell-cell junctions.

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