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Rathod M, Franz H, Beyersdorfer V, Wanuske MT, Leal-Fischer K, Hanns P, Stüdle C, Zimmermann A, Buczak K, Schinner C, Spindler V. DPM1 modulates desmosomal adhesion and epidermal differentiation through SERPINB5. J Cell Biol 2024; 223:e202305006. [PMID: 38477878 PMCID: PMC10937187 DOI: 10.1083/jcb.202305006] [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: 05/02/2023] [Revised: 11/30/2023] [Accepted: 01/23/2024] [Indexed: 03/14/2024] Open
Abstract
Glycosylation is essential to facilitate cell-cell adhesion and differentiation. We determined the role of the dolichol phosphate mannosyltransferase (DPM) complex, a central regulator for glycosylation, for desmosomal adhesive function and epidermal differentiation. Deletion of the key molecule of the DPM complex, DPM1, in human keratinocytes resulted in weakened cell-cell adhesion, impaired localization of the desmosomal components desmoplakin and desmoglein-2, and led to cytoskeletal organization defects in human keratinocytes. In a 3D organotypic human epidermis model, loss of DPM1 caused impaired differentiation with abnormally increased cornification, reduced thickness of non-corneal layers, and formation of intercellular gaps in the epidermis. Using proteomic approaches, SERPINB5 was identified as a DPM1-dependent interaction partner of desmoplakin. Mechanistically, SERPINB5 reduced desmoplakin phosphorylation at serine 176, which was required for strong intercellular adhesion. These results uncover a novel role of the DPM complex in connecting desmosomal adhesion with epidermal differentiation.
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Affiliation(s)
- Maitreyi Rathod
- Department of Biomedicine, University of Basel, Basel, Switzerland
- Institute of Anatomy and Experimental Morphology, University Clinic Hamburg-Eppendorf, Hamburg, Germany
| | - Henriette Franz
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Vivien Beyersdorfer
- Department of Biomedicine, University of Basel, Basel, Switzerland
- Institute of Anatomy and Experimental Morphology, University Clinic Hamburg-Eppendorf, Hamburg, Germany
| | | | | | - Pauline Hanns
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Chiara Stüdle
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Aude Zimmermann
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Katarzyna Buczak
- Proteomics Core Facility, Biocentre, University of Basel, Basel, Switzerland
| | - Camilla Schinner
- Department of Biomedicine, University of Basel, Basel, Switzerland
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Volker Spindler
- Department of Biomedicine, University of Basel, Basel, Switzerland
- Institute of Anatomy and Experimental Morphology, University Clinic Hamburg-Eppendorf, Hamburg, Germany
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2
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Fülle JB, de Almeida RA, Lawless C, Stockdale L, Yanes B, Lane EB, Garrod DR, Ballestrem C. Proximity Mapping of Desmosomes Reveals a Striking Shift in Their Molecular Neighborhood Associated With Maturation. Mol Cell Proteomics 2024; 23:100735. [PMID: 38342409 PMCID: PMC10943070 DOI: 10.1016/j.mcpro.2024.100735] [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: 05/04/2023] [Revised: 01/29/2024] [Accepted: 02/08/2024] [Indexed: 02/13/2024] Open
Abstract
Desmosomes are multiprotein adhesion complexes that link intermediate filaments to the plasma membrane, ensuring the mechanical integrity of cells across tissues, but how they participate in the wider signaling network to exert their full function is unclear. To investigate this, we carried out protein proximity mapping using biotinylation (BioID). The combined interactomes of the essential desmosomal proteins desmocollin 2a, plakoglobin, and plakophilin 2a (Pkp2a) in Madin-Darby canine kidney epithelial cells were mapped and their differences and commonalities characterized as desmosome matured from Ca2+ dependence to the mature, Ca2+-independent, hyper-adhesive state, which predominates in tissues. Results suggest that individual desmosomal proteins have distinct roles in connecting to cellular signaling pathways and that these roles alter substantially when cells change their adhesion state. The data provide further support for a dualistic concept of desmosomes in which the properties of Pkp2a differ from those of the other, more stable proteins. This body of data provides an invaluable resource for the analysis of desmosome function.
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Affiliation(s)
- Judith B Fülle
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, UK
| | | | - Craig Lawless
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, UK
| | - Liam Stockdale
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, UK
| | - Bian Yanes
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, UK
| | - E Birgitte Lane
- Skin Research Institute of Singapore, Agency of Science Technology and Research (A∗STAR), Singapore, Singapore
| | - David R Garrod
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, UK.
| | - Christoph Ballestrem
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, UK.
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3
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Yu H, Xiong M, Liu C, Xia D, Meng L, Zhang Z. The γ-Adducin 1-357 fragment promotes tau pathology. Front Aging Neurosci 2023; 15:1241750. [PMID: 37771520 PMCID: PMC10526357 DOI: 10.3389/fnagi.2023.1241750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 08/28/2023] [Indexed: 09/30/2023] Open
Abstract
Background Tau phosphorylation is a pathological hallmark of Alzheimer's disease (AD). Previously, we reported that the γ-adducin 1-357 fragment is present in the brains of AD patients. However, it remains unknown how γ-adducin regulates tau phosphorylation. Objective The aim of this project is to investigate the effects of the γ-adducin 1-357 fragment on tau phosphorylation and the kinases involved in this process. Methods Full-length γ-adducin or the γ-adducin 1-357 fragment was expressed in HEK293 cells, SH-SY5Y cells, and primary neurons. The phosphorylation of tau Ser396 was determined using Western blot and immunofluorescence. Tau P301S transgenic mice were injected with adeno-associated virus encoding full-length γ-adducin or γ-adducin 1-357 fragment to determine the phosphorylation of tau. Results The γ-adducin 1-357 fragment enhances tau phosphorylation at Ser396. Additionally, the expression of the γ-adducin 1-357 fragment leads to the activation of glycogen synthase kinase-3β (GSK-3β). This effect was mitigated by the GSK-3β inhibitor 4-Benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8). Conclusion The γ-adducin 1-357 fragment enhances tau phosphorylation by activating GSK3β. These results support that the fragmentation of γ-adducin may play a pivotal role in tau pathology.
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Affiliation(s)
- Honglu Yu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Min Xiong
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Congcong Liu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Danhao Xia
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Lanxia Meng
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
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4
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Yeruva S, Stangner K, Jungwirth A, Hiermaier M, Shoykhet M, Kugelmann D, Hertl M, Egami S, Ishii N, Koga H, Hashimoto T, Weis M, Beckmann BM, Biller R, Schüttler D, Kääb S, Waschke J. Catalytic antibodies in arrhythmogenic cardiomyopathy patients cleave desmoglein 2 and N-cadherin and impair cardiomyocyte cohesion. Cell Mol Life Sci 2023; 80:203. [PMID: 37450050 PMCID: PMC10348947 DOI: 10.1007/s00018-023-04853-1] [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: 02/10/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/18/2023]
Abstract
AIMS Arrhythmogenic cardiomyopathy (AC) is a severe heart disease predisposing to ventricular arrhythmias and sudden cardiac death caused by mutations affecting intercalated disc (ICD) proteins and aggravated by physical exercise. Recently, autoantibodies targeting ICD proteins, including the desmosomal cadherin desmoglein 2 (DSG2), were reported in AC patients and were considered relevant for disease development and progression, particularly in patients without underlying pathogenic mutations. However, it is unclear at present whether these autoantibodies are pathogenic and by which mechanisms show specificity for DSG2 and thus can be used as a diagnostic tool. METHODS AND RESULTS IgG fractions were purified from 15 AC patients and 4 healthy controls. Immunostainings dissociation assays, atomic force microscopy (AFM), Western blot analysis and Triton X-100 assays were performed utilizing human heart left ventricle tissue, HL-1 cells and murine cardiac slices. Immunostainings revealed that autoantibodies against ICD proteins are prevalent in AC and most autoantibody fractions have catalytic properties and cleave the ICD adhesion molecules DSG2 and N-cadherin, thereby reducing cadherin interactions as revealed by AFM. Furthermore, most of the AC-IgG fractions causing loss of cardiomyocyte cohesion activated p38MAPK, which is known to contribute to a loss of desmosomal adhesion in different cell types, including cardiomyocytes. In addition, p38MAPK inhibition rescued the loss of cardiomyocyte cohesion induced by AC-IgGs. CONCLUSION Our study demonstrates that catalytic autoantibodies play a pathogenic role by cleaving ICD cadherins and thereby reducing cardiomyocyte cohesion by a mechanism involving p38MAPK activation. Finally, we conclude that DSG2 cleavage by autoantibodies could be used as a diagnostic tool for AC.
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Affiliation(s)
- Sunil Yeruva
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstrasse 11, 80336, Munich, Germany
| | - Konstanze Stangner
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstrasse 11, 80336, Munich, Germany
| | - Anna Jungwirth
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstrasse 11, 80336, Munich, Germany
| | - Matthias Hiermaier
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstrasse 11, 80336, Munich, Germany
| | - Maria Shoykhet
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstrasse 11, 80336, Munich, Germany
- Department of Otorhinolarynology, Technical University of Munich and University Hospital rechts der Isar, Ismaningerstrasse 22, 81675, Munich, Germany
| | - Daniela Kugelmann
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstrasse 11, 80336, Munich, Germany
| | - Michael Hertl
- Department of Dermatology and Allergology, Philipps-University Marburg, 35037, Marburg, Germany
| | - Shohei Egami
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan
| | - Norito Ishii
- Department of Dermatology, Kurume University School of Medicine, Kurume, Japan
| | - Hiroshi Koga
- Department of Dermatology, Kurume University School of Medicine, Kurume, Japan
| | - Takashi Hashimoto
- Department of Dermatology, Graduate School of Medicine, Osaka City Metropolitan University, Osaka, Japan
| | - Michael Weis
- Krankenhaus Neuwittelsbach, Fachklinik Für Innere Medizin, Munich, Germany
| | - Britt-Maria Beckmann
- Department of Medicine I, University Hospital Munich, Ludwig-Maximilians University Munich (LMU), Campus Großhadern, Munich, Germany
- Institute of Legal Medicine, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - Ruth Biller
- ARVC-Selbsthilfe E.V, Patient Association, Munich, Germany
| | - Dominik Schüttler
- Department of Medicine I, University Hospital Munich, Ludwig-Maximilians University Munich (LMU), Campus Großhadern, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), Munich Heart Alliance (MHA), Partner Site Munich, Munich, Germany
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University Munich (LMU), Munich, Germany
- Interfaculty Center for Endocrine and Cardiovascular Disease Network Modelling and Clinical Transfer (ICON), LMU Munich, Munich, Germany
| | - Stefan Kääb
- Department of Medicine I, University Hospital Munich, Ludwig-Maximilians University Munich (LMU), Campus Großhadern, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), Munich Heart Alliance (MHA), Partner Site Munich, Munich, Germany
- Interfaculty Center for Endocrine and Cardiovascular Disease Network Modelling and Clinical Transfer (ICON), LMU Munich, Munich, Germany
- Member of the European Reference Network for rare, low prevalance and complex diseases of the heart , ERN GUARD-Heart, Munich, Germany
| | - Jens Waschke
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstrasse 11, 80336, Munich, Germany.
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Apremilast prevents blistering in human epidermis and stabilizes keratinocyte adhesion in pemphigus. Nat Commun 2023; 14:116. [PMID: 36624106 PMCID: PMC9829900 DOI: 10.1038/s41467-022-35741-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 12/21/2022] [Indexed: 01/10/2023] Open
Abstract
Pemphigus vulgaris is a life-threatening blistering skin disease caused by autoantibodies destabilizing desmosomal adhesion. Current therapies focus on suppression of autoantibody formation and thus treatments directly stabilizing keratinocyte adhesion would fulfill an unmet medical need. We here demonstrate that apremilast, a phosphodiesterase 4 inhibitor used in psoriasis, prevents skin blistering in pemphigus vulgaris. Apremilast abrogates pemphigus autoantibody-induced loss of keratinocyte cohesion in ex-vivo human epidermis, cultured keratinocytes in vitro and in vivo in mice. In parallel, apremilast inhibits keratin retraction as well as desmosome splitting, induces phosphorylation of plakoglobin at serine 665 and desmoplakin assembly into desmosomal plaques. We established a plakoglobin phospho-deficient mouse model that reveals fragile epidermis with altered organization of keratin filaments and desmosomal cadherins. In keratinocytes derived from these mice, intercellular adhesion is impaired and not rescued by apremilast. These data identify an unreported mechanism of desmosome regulation and propose that apremilast stabilizes keratinocyte adhesion and is protective in pemphigus.
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Fuchs M, Radeva MY, Spindler V, Vielmuth F, Kugelmann D, Waschke J. Cytoskeletal anchorage of different Dsg3 pools revealed by combination of hybrid STED/SMFS-AFM. Cell Mol Life Sci 2023; 80:25. [PMID: 36602635 PMCID: PMC9816259 DOI: 10.1007/s00018-022-04681-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 12/19/2022] [Accepted: 12/22/2022] [Indexed: 01/06/2023]
Abstract
Desmoglein 3 (Dsg3) is a desmosomal cadherin mediating cell adhesion within desmosomes and is the antigen of the autoimmune blistering skin disease pemphigus vulgaris. Therefore, understanding of the complex desmosome turnover process is of high biomedical relevance. Recently, super resolution microscopy was used to characterize desmosome composition and turnover. However, studies were limited because adhesion measurements on living cells were not possible in parallel. Before desmosomal cadherins are incorporated into nascent desmosomes, they are not bound to intermediate filaments but were suggested to be associated with the actin cytoskeleton. However, direct proof that adhesion of a pool of desmosomal cadherins is dependent on actin is missing. Here, we applied single-molecule force spectroscopy measurements with the novel single molecule hybrid-technique STED/SMFS-AFM to investigate the cytoskeletal anchorage of Dsg3 on living keratinocytes for the first time. By application of pharmacological agents we discriminated two different Dsg3 pools, only one of which is anchored to actin filaments. We applied the actin polymerization inhibitor Latrunculin B to modify the actin cytoskeleton and the PKCα activator PMA to modulate intermediate filament anchorage. On the cellular surface Dsg3 adhesion was actin-dependent. In contrast, at cell-cell contacts, Dsg3 adhesion was independent from actin but rather is regulated by PKC which is well established to control desmosome turn-over via intermediate filament anchorage. Taken together, using the novel STED/SMFS-AFM technique, we demonstrated the existence of two Dsg3 pools with different cytoskeletal anchorage mechanisms.
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Affiliation(s)
- Michael Fuchs
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Mariya Y Radeva
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Volker Spindler
- Department of Biomedicine and Institute of Anatomy, University of Basel, Basel, Switzerland
| | - Franziska Vielmuth
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Daniela Kugelmann
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Jens Waschke
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany.
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7
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Yeruva S, Körber L, Hiermaier M, Egu DT, Kempf E, Waschke J. Cholinergic signaling impairs cardiomyocyte cohesion. Acta Physiol (Oxf) 2022; 236:e13881. [PMID: 36039679 DOI: 10.1111/apha.13881] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 01/29/2023]
Abstract
AIM Cardiac autonomic nervous system (ANS) dysregulation is a hallmark of several cardiovascular diseases. Adrenergic signaling enhanced cardiomyocyte cohesion via PKA-mediated plakoglobin phosphorylation at serine 665, referred to as positive adhesiotropy. This study investigated cholinergic regulation of cardiomyocyte cohesion using muscarinic receptor agonist carbachol (CCH). METHODS Dissociation assays, Western blot analysis, immunostaining, atomic force microscopy (AFM), immunoprecipitation, transmission electron microscopy (TEM), triton assays, and siRNA knockdown of genes were performed in either HL-1 cells or plakoglobin (PG) wild type (Jup+/+ ) and knockout (Jup-/- ) mice, which served as a model for arrhythmogenic cardiomyopathy. RESULTS In HL-1 cells grown in norepinephrine (NE)-containing medium for baseline adrenergic stimulation, and murine cardiac slice cultures from Jup+/+ and Jup-/- mice CCH treatment impaired cardiomyocyte cohesion. Immunostainings and AFM experiments revealed that CCH reduced desmoglein 2 (DSG2) localization and binding at cell borders. Furthermore, CCH reduced intercalated disc plaque thickness in both Jup+/+ and Jup-/- mice, evidenced by TEM analysis. Immunoprecipitation experiments in HL-1 cells revealed no changes in DSG2 interaction with desmoplakin (DP), plakophilin 2 (PKP2), PG, and desmin (DES) after CCH treatment. However, knockdown of any of the above proteins abolished CCH-mediated loss of cardiomyocyte cohesion. Furthermore, in HL-1 cells, CCH inhibited adrenergic-stimulated ERK phosphorylation but not PG phosphorylation at serine 665. In addition, CCH activated the AKT/GSK-3β axis in the presence of NE. CONCLUSION Our results demonstrate that cholinergic signaling antagonizes the positive effect of adrenergic signaling on cardiomyocyte cohesion and thus causes negative adhesiotropy independent of PG phosphorylation.
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Affiliation(s)
- Sunil Yeruva
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilian-University (LMU) Munich, Munich, Germany
| | - Lars Körber
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilian-University (LMU) Munich, Munich, Germany
| | - Matthias Hiermaier
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilian-University (LMU) Munich, Munich, Germany
| | - Desalegn T Egu
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilian-University (LMU) Munich, Munich, Germany
| | - Ellen Kempf
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilian-University (LMU) Munich, Munich, Germany
| | - Jens Waschke
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilian-University (LMU) Munich, Munich, Germany
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Moztarzadeh S, Radeva MY, Sepic S, Schuster K, Hamad I, Waschke J, García-Ponce A. Lack of adducin impairs the stability of endothelial adherens and tight junctions and may be required for cAMP-Rac1-mediated endothelial barrier stabilization. Sci Rep 2022; 12:14940. [PMID: 36056066 PMCID: PMC9440001 DOI: 10.1038/s41598-022-18964-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 08/23/2022] [Indexed: 11/09/2022] Open
Abstract
Adducin (Add) is an actin binding protein participating in the stabilization of actin/spectrin networks, epithelial junctional turnover and cardiovascular disorders such as hypertension. Recently, we demonstrated that Add is required for adherens junctions (AJ) integrity. Here we hypothesized that Add regulates tight junctions (TJ) as well and may play a role in cAMP-mediated barrier enhancement. We evaluated the role of Add in MyEnd cells isolated from WT and Add-Knock-Out (KO) mice. Our results indicate that the lack of Add drastically alters the junctional localization and protein levels of major AJ and TJ components, including VE-Cadherin and claudin-5. We also showed that cAMP signaling induced by treatment with forskolin and rolipram (F/R) enhances the barrier integrity of WT but not Add-KO cells. The latter showed no junctional reorganization upon cAMP increase. The absence of Add also led to higher protein levels of the small GTPases Rac1 and RhoA. In vehicle-treated cells the activation level of Rac1 did not differ significantly when WT and Add-KO cells were compared. However, the lack of Add led to increased activity of RhoA. Moreover, F/R treatment triggered Rac1 activation only in WT cells. The function of Rac1 and RhoA per se was unaffected by the total ablation of Add, since direct activation with CN04 was still possible in both cell lines and led to improved endothelial barrier function. In the current study, we demonstrate that Add is required for the maintenance of endothelial barrier by regulating both AJ and TJ. Our data show that Add may act upstream of Rac1 as it is necessary for its activation via cAMP.
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Affiliation(s)
- Sina Moztarzadeh
- Chair of Vegetative Anatomy, Faculty of Medicine, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstraße 11, 80336, Munich, Germany
| | - Mariya Y Radeva
- Chair of Vegetative Anatomy, Faculty of Medicine, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstraße 11, 80336, Munich, Germany
| | - Sara Sepic
- Chair of Vegetative Anatomy, Faculty of Medicine, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstraße 11, 80336, Munich, Germany
| | - Katharina Schuster
- Chair of Vegetative Anatomy, Faculty of Medicine, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstraße 11, 80336, Munich, Germany
| | - Ibrahim Hamad
- Chair of Vegetative Anatomy, Faculty of Medicine, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstraße 11, 80336, Munich, Germany
| | - Jens Waschke
- Chair of Vegetative Anatomy, Faculty of Medicine, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstraße 11, 80336, Munich, Germany
| | - Alexander García-Ponce
- Chair of Vegetative Anatomy, Faculty of Medicine, Ludwig-Maximilians-University (LMU) Munich, Pettenkoferstraße 11, 80336, Munich, Germany.
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9
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Hiermaier M, Kugelmann D, Radeva MY, Didona D, Ghoreschi K, Farzan S, Hertl M, Waschke J. Pemphigus Foliaceus Autoantibodies Induce Redistribution Primarily of Extradesmosomal Desmoglein 1 in the Cell Membrane. Front Immunol 2022; 13:882116. [PMID: 35634274 PMCID: PMC9134081 DOI: 10.3389/fimmu.2022.882116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/20/2022] [Indexed: 11/23/2022] Open
Abstract
The autoimmune dermatosis pemphigus foliaceus (PF) is predominantly caused by IgG autoantibodies against the desmosomal cadherin desmoglein (Dsg) 1. The exact mechanisms that lead to the characteristic epidermal blistering are not yet fully understood. In the present study, we used a variety of biophysical methods to examine the fate of membrane-bound Dsg1 after incubation with PF patients’ IgG. Dispase-based dissociation assays confirmed that PF-IgG used for this study reduced intercellular adhesion in a manner dependent on phospholipase C (PLC)/Ca2+ and extracellular signal-regulated kinase (ERK) 1/2 signaling. Atomic force microscopy (AFM) revealed that Dsg1 binding on single molecule level paralleled effects on keratinocyte adhesion under the different conditions. Stimulated emission depletion (STED) super-resolution microscopy was used to investigate the localization of Dsg1 after PF-IgG incubation for 24 h. Under control conditions, Dsg1 was found to be in part co-localized with desmoplakin and thus inside of desmosomes as well as extra-desmosomal along the cell border. Incubation with PF-IgG reduced the extra-desmosomal Dsg1 fraction. In line with this, fluorescence recovery after photobleaching (FRAP) experiments demonstrated a strongly reduced mobility of Dsg1 in the cell membrane after PF-IgG treatment indicating remaining Dsg1 molecules were primarily located inside desmosomes. Mechanistically, experiments confirmed the involvement of PLC/Ca2+ since inhibition of PLC or 1,4,5-trisphosphate (IP3) receptor to reduce cytosolic Ca2+ reverted the effects of PF-IgG on Dsg1 intra-membrane mobility and localization. Taken together, our findings suggest that during the first 24 h PF-IgG induce redistribution predominantly of membrane-bound extradesmosomal Dsg1 in a PLC/Ca2+ dependent manner whereas Dsg1-containing desmosomes remain.
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Affiliation(s)
- Matthias Hiermaier
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, München, Germany
| | - Daniela Kugelmann
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, München, Germany
| | - Mariya Y Radeva
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, München, Germany
| | - Dario Didona
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Kamran Ghoreschi
- Department of Dermatology, Venereology and Allergology, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Department of Dermatology, University Medical Center, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Solimani Farzan
- Department of Dermatology, Venereology and Allergology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Hertl
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Jens Waschke
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, München, Germany
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10
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Fülle JB, Huppert H, Liebl D, Liu J, Alves de Almeida R, Yanes B, Wright GD, Lane EB, Garrod DR, Ballestrem C. Desmosome dualism - most of the junction is stable, but a plakophilin moiety is persistently dynamic. J Cell Sci 2021; 134:272445. [PMID: 34635908 DOI: 10.1242/jcs.258906] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 10/05/2021] [Indexed: 01/06/2023] Open
Abstract
Desmosomes, strong cell-cell junctions of epithelia and cardiac muscle, link intermediate filaments to cell membranes and mechanically integrate cells across tissues, dissipating mechanical stress. They comprise five major protein classes - desmocollins and desmogleins (the desmosomal cadherins), plakoglobin, plakophilins and desmoplakin - whose individual contribution to the structure and turnover of desmosomes is poorly understood. Using live-cell imaging together with fluorescence recovery after photobleaching (FRAP) and fluorescence loss and localisation after photobleaching (FLAP), we show that desmosomes consist of two contrasting protein moieties or modules: a very stable moiety of desmosomal cadherins, desmoplakin and plakoglobin, and a highly mobile plakophilin (Pkp2a). As desmosomes mature from Ca2+ dependence to Ca2+-independent hyper-adhesion, their stability increases, but Pkp2a remains highly mobile. We show that desmosome downregulation during growth-factor-induced cell scattering proceeds by internalisation of whole desmosomes, which still retain a stable moiety and highly mobile Pkp2a. This molecular mobility of Pkp2a suggests a transient and probably regulatory role for Pkp2a in desmosomes. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Judith B Fülle
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK.,Skin Research Institute of Singapore, Agency of Science Technology and Research (A*STAR), 8A Biomedical Grove, #06-06 Immunos, 138648 Singapore, Singapore
| | - Henri Huppert
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK.,Institute of Medical Biology, Agency of Science Technology and Research (A*STAR), 61 Biopolis Dr, 138673 Singapore, Singapore
| | - David Liebl
- A*STAR Microscopy Platform, Research Support Centre, Agency of Science Technology and Research (A*STAR), Biopolis 138673 Singapore, Singapore
| | - Jaron Liu
- Institute of Medical Biology, Agency of Science Technology and Research (A*STAR), 61 Biopolis Dr, 138673 Singapore, Singapore
| | - Rogerio Alves de Almeida
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK
| | - Bian Yanes
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK
| | - Graham D Wright
- Skin Research Institute of Singapore, Agency of Science Technology and Research (A*STAR), 8A Biomedical Grove, #06-06 Immunos, 138648 Singapore, Singapore.,A*STAR Microscopy Platform, Research Support Centre, Agency of Science Technology and Research (A*STAR), Biopolis 138673 Singapore, Singapore
| | - E Birgitte Lane
- Skin Research Institute of Singapore, Agency of Science Technology and Research (A*STAR), 8A Biomedical Grove, #06-06 Immunos, 138648 Singapore, Singapore
| | - David R Garrod
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK
| | - Christoph Ballestrem
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK
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11
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Schmitt T, Waschke J. Autoantibody-Specific Signalling in Pemphigus. Front Med (Lausanne) 2021; 8:701809. [PMID: 34434944 PMCID: PMC8381052 DOI: 10.3389/fmed.2021.701809] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/08/2021] [Indexed: 12/11/2022] Open
Abstract
Pemphigus is a severe autoimmune disease impairing barrier functions of epidermis and mucosa. Autoantibodies primarily target the desmosomal adhesion molecules desmoglein (Dsg) 1 and Dsg 3 and induce loss of desmosomal adhesion. Strikingly, autoantibody profiles in pemphigus correlate with clinical phenotypes. Mucosal-dominant pemphigus vulgaris (PV) is characterised by autoantibodies (PV-IgG) against Dsg3 whereas epidermal blistering in PV and pemphigus foliaceus (PF) is associated with autoantibodies against Dsg1. Therapy in pemphigus is evolving towards specific suppression of autoantibody formation and autoantibody depletion. Nevertheless, during the acute phase and relapses of the disease additional treatment options to stabilise desmosomes and thereby rescue keratinocyte adhesion would be beneficial. Therefore, the mechanisms by which autoantibodies interfere with adhesion of desmosomes need to be characterised in detail. Besides direct inhibition of Dsg adhesion, autoantibodies engage signalling pathways interfering with different steps of desmosome turn-over. With this respect, recent data indicate that autoantibodies induce separate signalling responses in keratinocytes via specific signalling complexes organised by Dsg1 and Dsg3 which transfer the signal of autoantibody binding into the cell. This hypothesis may also explain the different clinical pemphigus phenotypes.
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Affiliation(s)
- Thomas Schmitt
- Ludwig-Maximilian-Universität München, Anatomische Anstalt, Lehrstuhl Anatomie I - Vegetative Anatomie, Munich, Germany
| | - Jens Waschke
- Ludwig-Maximilian-Universität München, Anatomische Anstalt, Lehrstuhl Anatomie I - Vegetative Anatomie, Munich, Germany
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