1
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Gan WJ, Giri R, Begun J, Abud HE, Hardeman EC, Gunning PW, Yap AS, Noordstra I. A truncation mutant of adenomatous polyposis coli impairs apical cell extrusion through elevated epithelial tissue tension. Cytoskeleton (Hoboken) 2024. [PMID: 38984538 DOI: 10.1002/cm.21893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 05/21/2024] [Accepted: 06/27/2024] [Indexed: 07/11/2024]
Abstract
Tissue tension encompasses the mechanical forces exerted on solid tissues within animal bodies, originating from various sources such as cellular contractility, interactions with neighboring cells and the extracellular matrix. Emerging evidence indicates that an imbalance in such forces can influence structural organization, homeostasis, and potentially contribute to disease. For instance, heightened tissue tension can impede apical cell extrusion, leading to the retention of apoptotic or transformed cells. In this study, we investigate the potential role of adenomatous polyposis coli (APC) in modulating tissue tension. Our findings reveal that expression of an APC truncation mutant elevates epithelial tension via the RhoA/ROCK pathway. This elevation induces morphological alterations and hampers apoptotic cell extrusion in cultured epithelial cells and organoids, both of which could be mitigated by pharmacologically restoring the tissue tension. This raises the possibility that APC mutations may exert pathogenetic effects by altering tissue mechanics.
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Affiliation(s)
- Wan J Gan
- Centre for Cell Biology of Chronic Disease, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Rabina Giri
- Mater Research Institute, The University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia
- Faculty of Medicine, The University of Queensland, St. Lucia, Queensland, Australia
| | - Jakob Begun
- Mater Research Institute, The University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia
- Faculty of Medicine, The University of Queensland, St. Lucia, Queensland, Australia
| | - Helen E Abud
- Department of Anatomy and Developmental Biology, Development and Stem Cells Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Edna C Hardeman
- Faculty of Medicine and Health, School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Peter W Gunning
- Faculty of Medicine and Health, School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Alpha S Yap
- Centre for Cell Biology of Chronic Disease, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Ivar Noordstra
- Centre for Cell Biology of Chronic Disease, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
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2
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Baba H, Fujita T, Mizuno K, Tambo M, Toda S. Programming Spatial Cell Sorting by Engineering Cadherin Intracellular Activity. ACS Synth Biol 2024; 13:1705-1715. [PMID: 38726686 PMCID: PMC11197096 DOI: 10.1021/acssynbio.3c00774] [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: 12/29/2023] [Revised: 04/24/2024] [Accepted: 04/29/2024] [Indexed: 06/22/2024]
Abstract
The spatial sorting of cells into appropriate tissue compartments is essential for embryogenesis and tissue development. Spatial cell sorting is controlled by the interplay between cell surface affinity and intracellular mechanical properties. However, intracellular signaling that can sufficiently sort cell populations remains unexplored. In this study, we engineered chimeric cadherins by replacing the cadherin intracellular domain with cytoskeletal regulators to test their ability to induce spatial cell sorting. Using a fibroblast-based reconstitution system, we observed that Rac1 and RhoA activity in the cadherin tail induced outward and inward sorting, respectively. In particular, RhoA activity embedded cells toward the inside of E-cadherin-expressing spheroids and tumor spheroids, leading to tissue invagination. Despite the simplicity of chimeric cadherin design, our results indicate that differences in cadherin intracellular activities can determine the direction of spatial cell sorting, even when cell surface affinity is not different, and provide new molecular tools to engineer tissue architectures.
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Affiliation(s)
- Hikari Baba
- WPI
Nano Life Science Institute (NanoLSI), Kanazawa
University, Kanazawa, Ishikawa 920-1192, Japan
| | - Tomohiro Fujita
- WPI
Nano Life Science Institute (NanoLSI), Kanazawa
University, Kanazawa, Ishikawa 920-1192, Japan
- Graduate
School of Frontier Science Initiative, Kanazawa
University, Kanazawa, Ishikawa 920-1192, Japan
| | - Kosuke Mizuno
- WPI
Nano Life Science Institute (NanoLSI), Kanazawa
University, Kanazawa, Ishikawa 920-1192, Japan
- Graduate
School of Frontier Science Initiative, Kanazawa
University, Kanazawa, Ishikawa 920-1192, Japan
| | - Mai Tambo
- WPI
Nano Life Science Institute (NanoLSI), Kanazawa
University, Kanazawa, Ishikawa 920-1192, Japan
| | - Satoshi Toda
- WPI
Nano Life Science Institute (NanoLSI), Kanazawa
University, Kanazawa, Ishikawa 920-1192, Japan
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3
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Wang W, Camley BA. Limits on the accuracy of contact inhibition of locomotion. Phys Rev E 2024; 109:054408. [PMID: 38907435 PMCID: PMC11193850 DOI: 10.1103/physreve.109.054408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 03/25/2024] [Indexed: 06/24/2024]
Abstract
Cells that collide with each other repolarize away from contact, in a process called contact inhibition of locomotion (CIL), which is necessary for correct development of the embryo. CIL can occur even when cells make a micron-scale contact with a neighbor-much smaller than their size. How precisely can a cell sense cell-cell contact and repolarize in the correct direction? What factors control whether a cell recognizes it has contacted a neighbor? We propose a theoretical model for the limits of CIL where cells recognize the presence of another cell by binding the protein ephrin with the Eph receptor. This recognition is made difficult by the presence of interfering ligands that bind nonspecifically. Both theoretical predictions and simulation results show that it becomes more difficult to sense cell-cell contact when it is difficult to distinguish ephrin from the interfering ligands, or when there are more interfering ligands, or when the contact width decreases. However, the error of estimating contact position remains almost constant when the contact width changes. This happens because the cell gains spatial information largely from the boundaries of cell-cell contact. We study using statistical decision theory the likelihood of a false-positive CIL event in the absence of cell-cell contact, and the likelihood of a false negative where CIL does not occur when another cell is present. Our results suggest that the cell is more likely to make incorrect decisions when the contact width is very small or so large that it nears the cell's perimeter. However, in general, we find that cells have the ability to make reasonably reliable CIL decisions even for very narrow (micron-scale) contacts, even if the concentration of interfering ligands is ten times that of the correct ligands.
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Affiliation(s)
- Wei Wang
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Brian A Camley
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
- Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA
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4
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Quinn JM, Wang Y, Wood M, Flozak AS, Le PM, Yemelyanov A, Oakes PW, Gottardi CJ. α-catenin middle- and actin-binding domain unfolding mutants differentially impact epithelial strength and sheet migration. Mol Biol Cell 2024; 35:ar65. [PMID: 38507238 PMCID: PMC11151094 DOI: 10.1091/mbc.e23-01-0036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/23/2024] [Accepted: 03/15/2024] [Indexed: 03/22/2024] Open
Abstract
α-catenin (α-cat) displays force-dependent unfolding and binding to actin filaments through direct and indirect means, but features of adherens junction structure and function most vulnerable to loss of these allosteric mechanisms have not been directly compared. By reconstituting an α-cat F-actin-binding domain unfolding mutant known to exhibit enhanced binding to actin (α-cat-H0-FABD+) into α-cat knockout Madin Darby Canine Kidney (MDCK) cells, we show that partial loss of the α-cat catch bond mechanism (via an altered H0 α-helix) leads to stronger epithelial sheet integrity with greater colocalization between the α-cat-H0-FABD+ mutant and actin. α-cat-H0-FABD+ -expressing cells are less efficient at closing scratch-wounds, suggesting reduced capacity for more dynamic cell-cell coordination. Evidence that α-cat-H0-FABD+ is equally accessible to the conformationally sensitive α18 antibody epitope as WT α-cat and shows similar vinculin recruitment suggests this mutant engages lower tension cortical actin networks, as its M-domain is not persistently open. Conversely, α-cat-M-domain salt-bridge mutants with persistent recruitment of vinculin and phosphorylated myosin light chain show only intermediate monolayer adhesive strengths, but display less directionally coordinated and thereby slower migration speeds during wound-repair. These data show α-cat M- and FABD-unfolding mutants differentially impact cell-cell cohesion and migration properties, and suggest signals favoring α-cat-cortical actin interaction without persistent M-domain opening may improve epithelial monolayer strength through enhanced coupling to lower tension actin networks.
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Affiliation(s)
- Jeanne M. Quinn
- Department of Pulmonary Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
| | - Yuou Wang
- Department of Pulmonary Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
| | - Megan Wood
- Department of Pulmonary Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
| | - Annette S. Flozak
- Department of Pulmonary Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
| | - Phuong M. Le
- Department of Pulmonary Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
| | - Alex Yemelyanov
- Department of Pulmonary Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
| | - Patrick W. Oakes
- Department of Cell & Molecular Physiology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153
| | - Cara J. Gottardi
- Department of Pulmonary Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
- Cell & Developmental Biology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
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5
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Campàs O, Noordstra I, Yap AS. Adherens junctions as molecular regulators of emergent tissue mechanics. Nat Rev Mol Cell Biol 2024; 25:252-269. [PMID: 38093099 DOI: 10.1038/s41580-023-00688-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2023] [Indexed: 03/28/2024]
Abstract
Tissue and organ development during embryogenesis relies on the collective and coordinated action of many cells. Recent studies have revealed that tissue material properties, including transitions between fluid and solid tissue states, are controlled in space and time to shape embryonic structures and regulate cell behaviours. Although the collective cellular flows that sculpt tissues are guided by tissue-level physical changes, these ultimately emerge from cellular-level and subcellular-level molecular mechanisms. Adherens junctions are key subcellular structures, built from clusters of classical cadherin receptors. They mediate physical interactions between cells and connect biochemical signalling to the physical characteristics of cell contacts, hence playing a fundamental role in tissue morphogenesis. In this Review, we take advantage of the results of recent, quantitative measurements of tissue mechanics to relate the molecular and cellular characteristics of adherens junctions, including adhesion strength, tension and dynamics, to the emergent physical state of embryonic tissues. We focus on systems in which cell-cell interactions are the primary contributor to morphogenesis, without significant contribution from cell-matrix interactions. We suggest that emergent tissue mechanics is an important direction for future research, bridging cell biology, developmental biology and mechanobiology to provide a holistic understanding of morphogenesis in health and disease.
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Affiliation(s)
- Otger Campàs
- Cluster of Excellence Physics of Life, TU Dresden, Dresden, Germany.
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
- Center for Systems Biology Dresden, Dresden, Germany.
| | - Ivar Noordstra
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Alpha S Yap
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia.
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6
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Cao R, Tian H, Tian Y, Fu X. A Hierarchical Mechanotransduction System: From Macro to Micro. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2302327. [PMID: 38145330 PMCID: PMC10953595 DOI: 10.1002/advs.202302327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 10/27/2023] [Indexed: 12/26/2023]
Abstract
Mechanotransduction is a strictly regulated process whereby mechanical stimuli, including mechanical forces and properties, are sensed and translated into biochemical signals. Increasing data demonstrate that mechanotransduction is crucial for regulating macroscopic and microscopic dynamics and functionalities. However, the actions and mechanisms of mechanotransduction across multiple hierarchies, from molecules, subcellular structures, cells, tissues/organs, to the whole-body level, have not been yet comprehensively documented. Herein, the biological roles and operational mechanisms of mechanotransduction from macro to micro are revisited, with a focus on the orchestrations across diverse hierarchies. The implications, applications, and challenges of mechanotransduction in human diseases are also summarized and discussed. Together, this knowledge from a hierarchical perspective has the potential to refresh insights into mechanotransduction regulation and disease pathogenesis and therapy, and ultimately revolutionize the prevention, diagnosis, and treatment of human diseases.
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Affiliation(s)
- Rong Cao
- Department of Endocrinology and MetabolismCenter for Diabetes Metabolism ResearchState Key Laboratory of Biotherapy and Cancer CenterWest China Medical SchoolWest China HospitalSichuan University and Collaborative Innovation CenterChengduSichuan610041China
| | - Huimin Tian
- Department of Endocrinology and MetabolismCenter for Diabetes Metabolism ResearchState Key Laboratory of Biotherapy and Cancer CenterWest China Medical SchoolWest China HospitalSichuan University and Collaborative Innovation CenterChengduSichuan610041China
| | - Yan Tian
- Department of Endocrinology and MetabolismCenter for Diabetes Metabolism ResearchState Key Laboratory of Biotherapy and Cancer CenterWest China Medical SchoolWest China HospitalSichuan University and Collaborative Innovation CenterChengduSichuan610041China
| | - Xianghui Fu
- Department of Endocrinology and MetabolismCenter for Diabetes Metabolism ResearchState Key Laboratory of Biotherapy and Cancer CenterWest China Medical SchoolWest China HospitalSichuan University and Collaborative Innovation CenterChengduSichuan610041China
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7
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Nakamura F. The Role of Mechanotransduction in Contact Inhibition of Locomotion and Proliferation. Int J Mol Sci 2024; 25:2135. [PMID: 38396812 PMCID: PMC10889191 DOI: 10.3390/ijms25042135] [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: 12/19/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/25/2024] Open
Abstract
Contact inhibition (CI) represents a crucial tumor-suppressive mechanism responsible for controlling the unbridled growth of cells, thus preventing the formation of cancerous tissues. CI can be further categorized into two distinct yet interrelated components: CI of locomotion (CIL) and CI of proliferation (CIP). These two components of CI have historically been viewed as separate processes, but emerging research suggests that they may be regulated by both distinct and shared pathways. Specifically, recent studies have indicated that both CIP and CIL utilize mechanotransduction pathways, a process that involves cells sensing and responding to mechanical forces. This review article describes the role of mechanotransduction in CI, shedding light on how mechanical forces regulate CIL and CIP. Emphasis is placed on filamin A (FLNA)-mediated mechanotransduction, elucidating how FLNA senses mechanical forces and translates them into crucial biochemical signals that regulate cell locomotion and proliferation. In addition to FLNA, trans-acting factors (TAFs), which are proteins or regulatory RNAs capable of directly or indirectly binding to specific DNA sequences in distant genes to regulate gene expression, emerge as sensitive players in both the mechanotransduction and signaling pathways of CI. This article presents methods for identifying these TAF proteins and profiling the associated changes in chromatin structure, offering valuable insights into CI and other biological functions mediated by mechanotransduction. Finally, it addresses unanswered research questions in these fields and delineates their possible future directions.
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Affiliation(s)
- Fumihiko Nakamura
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
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8
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Arslan FN, Hannezo É, Merrin J, Loose M, Heisenberg CP. Adhesion-induced cortical flows pattern E-cadherin-mediated cell contacts. Curr Biol 2024; 34:171-182.e8. [PMID: 38134934 DOI: 10.1016/j.cub.2023.11.067] [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: 05/02/2023] [Revised: 10/25/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023]
Abstract
Metazoan development relies on the formation and remodeling of cell-cell contacts. Dynamic reorganization of adhesion receptors and the actomyosin cell cortex in space and time plays a central role in cell-cell contact formation and maturation. Nevertheless, how this process is mechanistically achieved when new contacts are formed remains unclear. Here, by building a biomimetic assay composed of progenitor cells adhering to supported lipid bilayers functionalized with E-cadherin ectodomains, we show that cortical F-actin flows, driven by the depletion of myosin-2 at the cell contact center, mediate the dynamic reorganization of adhesion receptors and cell cortex at the contact. E-cadherin-dependent downregulation of the small GTPase RhoA at the forming contact leads to both a depletion of myosin-2 and a decrease of F-actin at the contact center. At the contact rim, in contrast, myosin-2 becomes enriched by the retraction of bleb-like protrusions, resulting in a cortical tension gradient from the contact rim to its center. This tension gradient, in turn, triggers centrifugal F-actin flows, leading to further accumulation of F-actin at the contact rim and the progressive redistribution of E-cadherin from the contact center to the rim. Eventually, this combination of actomyosin downregulation and flows at the contact determines the characteristic molecular organization, with E-cadherin and F-actin accumulating at the contact rim, where they are needed to mechanically link the contractile cortices of the adhering cells.
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Affiliation(s)
- Feyza Nur Arslan
- Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg 3400, Austria; Institute of Bioengineering, École polytechnique fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Édouard Hannezo
- Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg 3400, Austria
| | - Jack Merrin
- Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg 3400, Austria
| | - Martin Loose
- Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg 3400, Austria
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9
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Mann Z, Yap AS. Talking with force at cell-cell adhesions. Nat Cell Biol 2024; 26:26-28. [PMID: 38228828 DOI: 10.1038/s41556-023-01263-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Affiliation(s)
- Zoya Mann
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland, Australia
| | - Alpha S Yap
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland, Australia.
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10
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Schimmel L, Noordstra I. Epithelial cell spreading assay on E-cadherin-coated glass or PDMS substrates for microscopy-based analysis of cadherin adhesions. STAR Protoc 2023; 4:102626. [PMID: 37792537 PMCID: PMC10568414 DOI: 10.1016/j.xpro.2023.102626] [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: 08/03/2023] [Revised: 08/31/2023] [Accepted: 09/18/2023] [Indexed: 10/06/2023] Open
Abstract
Adherens junctions (AJs) are multi-protein adhesion structures that couple contractile actomyosin networks of epithelial cells within a tissue. Here, we present an epithelial cell spreading assay on E-cadherin-coated glass or polydimethylsiloxane (PDMS) substrates for detailed microscopy-based analysis of cadherin adhesions. We describe steps for preparation of glass coverslips and PDMS gels, E-cadherin coating, and epithelial cell spreading. Epithelial cells can be seeded on E-cadherin-coated surfaces, thereby mimicking AJ formation in X-Y dimension, making it suitable for microscopy analysis. For complete details on the use and execution of this protocol, please refer to Noordstra et al. (2023).1.
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Affiliation(s)
- Lilian Schimmel
- Centre for Cell Biology of Chronic Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Ivar Noordstra
- Centre for Cell Biology of Chronic Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia.
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Wang Y, Yemelyanov A, Go CD, Kim S, Quinn JM, Flozak AS, Le PM, Liang S, Claude-Gingras A, Ikura M, Ishiyama N, Gottardi CJ. α-catenin mechanosensitivity as a route to cytokinesis failure through sequestration of LZTS2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.25.554884. [PMID: 37662204 PMCID: PMC10473746 DOI: 10.1101/2023.08.25.554884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Epithelial cells can become polyploid upon tissue injury, but mechanosensitive cues that trigger this state are poorly understood. Using α-catenin (α-cat) knock-out Madin Darby Canine Kidney (MDCK) cells reconstituted with wild-type and mutant forms of α-cat as a model system, we find that an established α-cat actin-binding domain unfolding mutant designed to reduce force-sensitive binding to F-actin (α-cat-H0-FABD+) can promote cytokinesis failure, particularly along epithelial wound-fronts. Enhanced α-cat coupling to cortical actin is neither sufficient nor mitotic cell-autonomous for cytokinesis failure, but critically requires the mechanosensitive Middle-domain (M1-M2-M3) and neighboring cells. Disease relevant α-cat M-domain missense mutations known to cause a form of retinal pattern dystrophy (α-cat E307K or L436P) are associated with elevated binucleation rates via cytokinesis failure. Similar binucleation rates are seen in cells expressing an α-cat salt-bridge destabilizing mutant (R551A) designed to promote M2-M3 domain unfurling at lower force thresholds. Since binucleation is strongly enhanced by removal of the M1 as opposed to M2-M3 domains, cytokinetic fidelity is most sensitive to α-cat M2-M3 domain opening. To identify α-cat conformation-dependent proximity partners that contribute to cytokinesis, we used a biotin-ligase approach to distinguished proximity partners that show enhanced recruitment upon α-cat M-domain unfurling (R551A). We identified Leucine Zipper Tumor Suppressor 2 (LZTS2), an abscission factor previously implicated in cytokinesis. We confirm that LZTS2 enriches at the midbody, but discover it also localizes to tight and tricellular junctions. LZTS2 knock-down promotes binucleation in both MDCK and Retinal Pigmented Epithelial (RPE) cells. α-cat mutants with persistent M2-M3 domain opening showed elevated junctional enrichment of LZTS2 from the cytosol compared α-cat wild-type cells. These data implicate LZTS2 as a mechanosensitive effector of α-cat that is critical for cytokinetic fidelity. This model rationalizes how persistent mechano-activation of α-cat may drive tension-induced polyploidization of epithelia post-injury and suggests an underlying mechanism for how pathogenic α-cat mutations drive macular dystrophy.
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Affiliation(s)
- Yuou Wang
- Department of Pulmonary Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Alex Yemelyanov
- Department of Pulmonary Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Christopher D. Go
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health, Toronto, Ontario, M5G 1X5, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Sun Kim
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health, Toronto, Ontario, M5G 1X5, Canada
| | - Jeanne M. Quinn
- Department of Pulmonary Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Annette S. Flozak
- Department of Pulmonary Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Phuong M. Le
- Department of Pulmonary Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Shannon Liang
- Department of Pulmonary Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Anne Claude-Gingras
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health, Toronto, Ontario, M5G 1X5, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Mitsu Ikura
- Department of Medical Biophysics, University Health Network, Princess Margaret Cancer Center, University of Toronto, Toronto, Ontario, Canada
| | - Noboru Ishiyama
- Department of Medical Biophysics, University Health Network, Princess Margaret Cancer Center, University of Toronto, Toronto, Ontario, Canada
| | - Cara J. Gottardi
- Department of Pulmonary Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
- Cell & Developmental Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
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