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Steinert L, Fuchs M, Sigmund AM, Didona D, Hudemann C, Möbs C, Hertl M, Hashimoto T, Waschke J, Vielmuth F. Desmosomal Hyper-adhesion Affects Direct Inhibition of Desmoglein Interactions in Pemphigus. J Invest Dermatol 2024:S0022-202X(24)00308-7. [PMID: 38677661 DOI: 10.1016/j.jid.2024.03.042] [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: 01/26/2023] [Revised: 02/06/2024] [Accepted: 03/02/2024] [Indexed: 04/29/2024]
Abstract
During differentiation, keratinocytes acquire a strong, hyper-adhesive state, where desmosomal cadherins interact calcium ion independently. Previous data indicate that hyper-adhesion protects keratinocytes from pemphigus vulgaris autoantibody-induced loss of intercellular adhesion, although the underlying mechanism remains to be elucidated. Thus, in this study, we investigated the effect of hyper-adhesion on pemphigus vulgaris autoantibody-induced direct inhibition of desmoglein (DSG) 3 interactions by atomic force microscopy. Hyper-adhesion abolished loss of intercellular adhesion and corresponding morphological changes of all pathogenic antibodies used. Pemphigus autoantibodies putatively targeting several parts of the DSG3 extracellular domain and 2G4, targeting a membrane-proximal domain of DSG3, induced direct inhibition of DSG3 interactions only in non-hyper-adhesive keratinocytes. In contrast, AK23, targeting the N-terminal extracellular domain 1 of DSG3, caused direct inhibition under both adhesive states. However, antibody binding to desmosomal cadherins was not different between the distinct pathogenic antibodies used and was not changed during acquisition of hyper-adhesion. In addition, heterophilic DSC3-DSG3 and DSG2-DSG3 interactions did not cause reduced susceptibility to direct inhibition under hyper-adhesive condition in wild-type keratinocytes. Taken together, the data suggest that hyper-adhesion reduces susceptibility to autoantibody-induced direct inhibition in dependency on autoantibody-targeted extracellular domain but also demonstrate that further mechanisms are required for the protective effect of desmosomal hyper-adhesion in pemphigus vulgaris.
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Affiliation(s)
- Letyfee Steinert
- Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Michael Fuchs
- Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Anna M Sigmund
- Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Dario Didona
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, Germany
| | - Christoph Hudemann
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, Germany
| | - Christian Möbs
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, Germany
| | - Michael Hertl
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, Germany
| | - Takashi Hashimoto
- Department of Dermatology, Graduate School of Medicine, Osaka City Metropolitan University, Osaka, Japan
| | - Jens Waschke
- Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Franziska Vielmuth
- Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany.
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2
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Egu DT, Schmitt T, Ernst N, Ludwig RJ, Fuchs M, Hiermaier M, Moztarzadeh S, Morón CS, Schmidt E, Beyersdorfer V, Spindler V, Steinert LS, Vielmuth F, Sigmund AM, Waschke J. EGFR Inhibition by Erlotinib Rescues Desmosome Ultrastructure and Keratin Anchorage and Protects against Pemphigus Vulgaris IgG-Induced Acantholysis in Human Epidermis. J Invest Dermatol 2024:S0022-202X(24)00301-4. [PMID: 38642796 DOI: 10.1016/j.jid.2024.03.040] [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: 10/06/2023] [Revised: 03/23/2024] [Accepted: 03/25/2024] [Indexed: 04/22/2024]
Abstract
Pemphigus is a severe blistering disease caused by autoantibodies primarily against the desmosomal cadherins desmoglein (DSG)1 and DSG3, which impair desmosome integrity. Especially for the acute phase, additional treatment options allowing to reduce corticosteroids would fulfill an unmet medical need. In this study, we provide evidence that EGFR inhibition by erlotinib ameliorates pemphigus vulgaris IgG-induced acantholysis in intact human epidermis. Pemphigus vulgaris IgG caused phosphorylation of EGFR (Y845) and Rous sarcoma-related kinase in human epidermis. In line with this, a phosphotyrosine kinome analysis revealed a robust response associated with EGFR and Rous sarcoma-related kinase family kinase signaling in response to pemphigus vulgaris IgG but not to pemphigus foliaceus autoantibodies. Erlotinib inhibited pemphigus vulgaris IgG-induced epidermal blistering and EGFR phosphorylation, loss of desmosomes, as well as ultrastructural alterations of desmosome size, plaque symmetry, and keratin filament insertion and restored the desmosome midline considered as hallmark of mature desmosomes. Erlotinib enhanced both single-molecule DSG3-binding frequency and strength and delayed DSG3 fluorescence recovery, supporting that EGFR inhibition increases DSG3 availability and cytoskeletal anchorage. Our data indicate that EGFR is a promising target for pemphigus therapy owing to its link to several signaling pathways known to be involved in pemphigus pathogenesis.
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Affiliation(s)
- Desalegn Tadesse Egu
- Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Thomas Schmitt
- Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Nancy Ernst
- Lübeck Institute of Experimental Dermatology, University of Lübeck, Lübeck, Germany; Department of Dermatology, University of Lübeck, Lübeck, Germany
| | - Ralf Joachim Ludwig
- Lübeck Institute of Experimental Dermatology, University of Lübeck, Lübeck, Germany; Department of Dermatology, University of Lübeck, Lübeck, Germany
| | - Michael Fuchs
- Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Matthias Hiermaier
- Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Sina Moztarzadeh
- Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Carla Sebastià Morón
- Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany; Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
| | - Enno Schmidt
- Lübeck Institute of Experimental Dermatology, University of Lübeck, Lübeck, Germany; Department of Dermatology, University of Lübeck, Lübeck, Germany
| | - Vivien Beyersdorfer
- Department of Biomedicine, University of Basel, Basel, Switzerland; Institute of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Volker Spindler
- Department of Biomedicine, University of Basel, Basel, Switzerland; Institute of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Letyfee Sarah Steinert
- Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Franziska Vielmuth
- Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Anna Magdalena Sigmund
- Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Jens Waschke
- Institute of Anatomy, Faculty of Medicine, Ludwig Maximilian University of Munich, Munich, Germany.
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Ghorai T, Sarkar A, Roy A, Bhowmick B, Nayak D, Das S. Role of auto-antibodies in the mechanisms of dengue pathogenesis and its progression: a comprehensive review. Arch Microbiol 2024; 206:214. [PMID: 38616229 DOI: 10.1007/s00203-024-03954-0] [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: 03/01/2024] [Revised: 03/27/2024] [Accepted: 04/02/2024] [Indexed: 04/16/2024]
Abstract
A complex interaction among virulence factors, host-genes and host immune system is considered to be responsible for dengue virus (DENV) infection and disease progression. Generation of auto-antibodies during DENV infection is a major phenomenon that plays a role in the pathophysiology of dengue hemorrhagic fever and dengue shock syndrome. Hemostasis, thrombocytopenia, hepatic endothelial dysfunction, and autoimmune blistering skin disease (pemphigus) are different clinical manifestations of dengue pathogenesis; produced due to the molecular mimicry of DENV proteins with self-antigens like coagulation factors, platelets and endothelial cell proteins. This review elaborately describes the current advancements in auto-antibody-mediated immunopathogenesis which inhibits coagulation cascade and promotes hyperfibrinolysis. Auto-antibodies like anti-endothelial cell antibodies-mediated hepatic inflammation during severe DENV infection have also been discussed. Overall, this comprehensive review provides insight to target auto-antibodies that may act as potential biomarkers for disease severity, and a ground for the development of therapeutic strategy against DENV.
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Affiliation(s)
- Tanusree Ghorai
- Virology Laboratory, DAC Regional Research Institute, Kolkata, India
| | - Avipsha Sarkar
- Virology Laboratory, DAC Regional Research Institute, Kolkata, India
| | - Anirban Roy
- Virology Laboratory, DAC Regional Research Institute, Kolkata, India
| | - Bijita Bhowmick
- Virology Laboratory, DAC Regional Research Institute, Kolkata, India
| | | | - Satadal Das
- Virology Laboratory, DAC Regional Research Institute, Kolkata, India.
- Peerless Hospital and B.K. Roy Research Centre, Kolkata, India.
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Hudemann C, Exner Y, Pollmann R, Schneider K, Zakrzewicz A, Feldhoff S, Schmidt T, Spindler V, Rafei-Shamsabadi D, Völlner F, Waschke J, Tikkanen R, Hertl M, Eming R. IgG against the Membrane-Proximal Portion of the Desmoglein 3 Ectodomain Induces Loss of Keratinocyte Adhesion, a Hallmark in Pemphigus Vulgaris. J Invest Dermatol 2023; 143:254-263.e3. [PMID: 36089007 DOI: 10.1016/j.jid.2022.07.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 07/18/2022] [Accepted: 07/25/2022] [Indexed: 01/25/2023]
Abstract
Pemphigus vulgaris is a severe autoimmune blistering disease characterized by IgG autoantibodies (auto-abs) against the desmosomal adhesion molecules desmoglein (DSG) 3 and DSG1. Underlying mechanisms leading to blister formation upon binding of DSG-specific IgG auto-abs are not fully understood. Numerous studies showed the pathogenicity of IgG auto-ab binding to the aminoterminal region 1 (EC1) of the DSG3 ectodomain. However, auto-abs in pemphigus vulgaris are polyclonal, including IgG against both aminoterminal- and membrane-proximal epitopes of the DSG3 ectodomain. In this study, the pathogenicity of a previously uncharacterized murine monoclonal IgG antibody, 2G4, directed against the membrane-proximal region (EC5) of the DSG3 ectodomain was characterized and tested in various specificity and functionality assays. The results clearly show that 2G4 is capable of inhibiting intercellular keratinocyte adhesion and of inducing cellular DSG3 redistribution by activation of the p38MAPK signal transduction pathway. In this study, we provide evidence that an IgG auto-abs directed against the membrane-proximal region EC5 of DSG3 induces acantholysis, the hallmark in pemphigus vulgaris. These findings challenge the current concept that IgG auto-abs targeting the NH2-terminal portion of the DSG3 ectodomain are pathogenic only. Our study provides further aspects for a deeper understanding of desmosomal keratinocyte adhesion and improves our insight into the complex auto-ab‒induced blister formation in pemphigus vulgaris.
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Affiliation(s)
- Christoph Hudemann
- Department of Dermatology and Allergology, Philipps-University Marburg, Marburg, Germany.
| | - Yvonne Exner
- Department of Dermatology and Allergology, Philipps-University Marburg, Marburg, Germany
| | - Robert Pollmann
- Department of Dermatology and Allergology, Philipps-University Marburg, Marburg, Germany
| | - Karina Schneider
- Department of Dermatology and Allergology, Philipps-University Marburg, Marburg, Germany
| | - Anna Zakrzewicz
- Institute of Biochemistry, Medical Faculty, Justus-Liebig-University Giessen, Giessen, Germany
| | - Simon Feldhoff
- Institute of Biochemistry, Medical Faculty, Justus-Liebig-University Giessen, Giessen, Germany
| | - Thomas Schmidt
- Department of Dermatology and Allergology, Philipps-University Marburg, Marburg, Germany
| | - Volker Spindler
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians University Munich, Munich, Germany
| | - David Rafei-Shamsabadi
- Department of Dermatology and Allergology, Philipps-University Marburg, Marburg, Germany; Department of Dermatology and Venereology, Medical Center, University of Freiburg, Freiburg, Germany
| | - Frauke Völlner
- Institute of Biochemistry, Medical Faculty, Justus-Liebig-University Giessen, Giessen, Germany
| | - Jens Waschke
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians University Munich, Munich, Germany
| | - Ritva Tikkanen
- Institute of Biochemistry, Medical Faculty, Justus-Liebig-University Giessen, Giessen, Germany
| | - Michael Hertl
- Department of Dermatology and Allergology, Philipps-University Marburg, Marburg, Germany
| | - Rüdiger Eming
- Department of Dermatology and Allergology, Philipps-University Marburg, Marburg, Germany; Department of Dermatology, Venerology and Allergology, German Armed Forces Central Hospital Koblenz, Koblenz, 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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Schmitt T, Hudemann C, Moztarzadeh S, Hertl M, Tikkanen R, Waschke J. Dsg3 epitope-specific signalling in pemphigus. Front Immunol 2023; 14:1163066. [PMID: 37143675 PMCID: PMC10151755 DOI: 10.3389/fimmu.2023.1163066] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 03/31/2023] [Indexed: 05/06/2023] Open
Abstract
Introduction Pemphigus is an autoantibody driven disease that impairs the barrier function of the skin and mucosa by disrupting desmosomes and thereby impeding cellular cohesion. It is known that the different clinical phenotypes of pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are dependent on the autoantibody profile and target antigens that, amongst others, are primarily desmoglein (Dsg)1 and/or Dsg3 for PV and Dsg1 for PF. However, it was reported that autoantibodiesagainst different epitopes of Dsg1 and Dsg3 can be pathogenic or not. The underlying mechanisms are very complex and involve both direct inhibition of Dsg interactions and downstream signalling. The aim of this study was to find out whether there is target-epitope-specific Dsg3 signalling by comparing the effects of the two pathogenic murine IgGs, 2G4 and AK23. Methods Dispase-based dissociation assay, Western Blot analysis, Stimulated emission depletion microscopy, Fura-based Ca2+ flux measurements, Rho/Rac G-Protein-linked immunosorbent assay, Enzyme-linked immunosorbent assay. Results The IgGs are directed against the EC5 and EC1 domain of Dsg3, respectively. The data show that 2G4 was less effective in causing loss of cell adhesion, compared to AK23. STED imaging revealed that both autoantibodies had similar effects on keratin retraction and reduction of desmosome number whereas only AK23 induced Dsg3 depletion. Moreover, both antibodies induced phosphorylation of p38MAPK and Akt whereas Src was phosphorylated upon treatment with AK23 only. Interestingly, Src and Akt activation were p38MAPK-dependent. All pathogenic effects were rescued by p38MAPK inhibition and AK23-mediated effects were also ameliorated by Src inhibition. Discussion The results give first insights into pemphigus autoantibody-induced Dsg3 epitope-specific signalling which is involved in pathogenic events such as Dsg3 depletion.
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Affiliation(s)
- Thomas Schmitt
- Instiute of Anatomy, Faculty of Medicine, Chair of Vegetative Anatomy, Ludwig-Maximilian -Universität (LMU) Munich, München, Germany
| | - Christoph Hudemann
- Department of Dermatology and Allergology, Philipps-University Marburg, Marburg, Germany
| | - Sina Moztarzadeh
- Instiute of Anatomy, Faculty of Medicine, Chair of Vegetative Anatomy, Ludwig-Maximilian -Universität (LMU) Munich, München, Germany
| | - Michael Hertl
- Department of Dermatology and Allergology, Philipps-University Marburg, Marburg, Germany
| | - Ritva Tikkanen
- Institute of Biochemistry, Medical Faculty, Justus-Liebig-University Giessen, Giessen, Germany
| | - Jens Waschke
- Instiute of Anatomy, Faculty of Medicine, Chair of Vegetative Anatomy, Ludwig-Maximilian -Universität (LMU) Munich, München, Germany
- *Correspondence: Jens Waschke,
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Brescacin A, Baig Z, Bhinder J, Lin S, Brar L, Cirillo N. What protein kinases are crucial for acantholysis and blister formation in pemphigus vulgaris? A systematic review. J Cell Physiol 2022; 237:2825-2837. [PMID: 35616233 PMCID: PMC9540544 DOI: 10.1002/jcp.30784] [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: 03/04/2022] [Revised: 04/21/2022] [Accepted: 04/26/2022] [Indexed: 01/18/2023]
Abstract
Pemphigus vulgaris (PV) is a potentially fatal autoimmune blistering disease characterized by cell-cell detachment (or acantholysis) and blister formation. While the signaling mechanisms that associate with skin/mucosal blistering are being elucidated, specific treatment strategies targeting PV-specific pathomechanisms, particularly kinase signaling, have yet to be established. Hence, the aim of this review was to systematically evaluate molecules in the class of kinases that are essential for acantholysis and blister formation and are therefore candidates for targeted therapy. English articles from PubMed and Scopus databases were searched, and included in vitro, in vivo, and human studies that investigated the role of kinases in PV. We selected studies, extracted data and assessed risk of bias in duplicates and the results were reported according to the methodology outlined by the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). The risk of bias assessment was performed on in vivo studies utilizing SYRCLE's risk of bias tool. Thirty-five studies were included that satisfied the pathogenicity criterion of kinases in PV, the vast majority being experimental models that used PV sera (n = 13) and PV-IgG (n = 22). Inhibition of kinase activity (p38MAPK, PKC, TK, c-Src, EGFR, ERK, mTOR, BTK, and CDK2) was achieved mostly by pharmacological means. Overall, we found substantial evidence that kinase inhibition reduced PV-associated phosphorylation events and keratinocyte disassociation, prevented acantholysis, and blocked blister formation. However, the scarce adherence to standardized reporting systems and the experimental protocols/models used did limit the internal and external validity of these studies. In summary, this systematic review highlighted the pathogenic intracellular events mediated by kinases in PV acantholysis and presented kinase signaling as a promising avenue for translational research. In particular, the molecules identified and discussed in this study represent potential candidates for the development of mechanism-based interventions in PV.
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Affiliation(s)
- Adriano Brescacin
- Melbourne Dental School, Faculty of Medicine, Dentistry & Health Sciences, University of Melbourne, Carlton, Victoria, Australia
| | - Zunaira Baig
- Melbourne Dental School, Faculty of Medicine, Dentistry & Health Sciences, University of Melbourne, Carlton, Victoria, Australia
| | - Jaspreet Bhinder
- Melbourne Dental School, Faculty of Medicine, Dentistry & Health Sciences, University of Melbourne, Carlton, Victoria, Australia
| | - Sen Lin
- Melbourne Dental School, Faculty of Medicine, Dentistry & Health Sciences, University of Melbourne, Carlton, Victoria, Australia
| | - Lovejot Brar
- Melbourne Dental School, Faculty of Medicine, Dentistry & Health Sciences, University of Melbourne, Carlton, Victoria, Australia
| | - Nicola Cirillo
- Melbourne Dental School, Faculty of Medicine, Dentistry & Health Sciences, University of Melbourne, Carlton, Victoria, Australia
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Egu DT, Schmitt T, Waschke J. Mechanisms Causing Acantholysis in Pemphigus-Lessons from Human Skin. Front Immunol 2022; 13:884067. [PMID: 35720332 PMCID: PMC9205406 DOI: 10.3389/fimmu.2022.884067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 04/12/2022] [Indexed: 11/13/2022] Open
Abstract
Pemphigus vulgaris (PV) is an autoimmune bullous skin disease caused primarily by autoantibodies (PV-IgG) against the desmosomal adhesion proteins desmoglein (Dsg)1 and Dsg3. PV patient lesions are characterized by flaccid blisters and ultrastructurally by defined hallmarks including a reduction in desmosome number and size, formation of split desmosomes, as well as uncoupling of keratin filaments from desmosomes. The pathophysiology underlying the disease is known to involve several intracellular signaling pathways downstream of PV-IgG binding. Here, we summarize our studies in which we used transmission electron microscopy to characterize the roles of signaling pathways in the pathogenic effects of PV-IgG on desmosome ultrastructure in a human ex vivo skin model. Blister scores revealed inhibition of p38MAPK, ERK and PLC/Ca2+ to be protective in human epidermis. In contrast, inhibition of Src and PKC, which were shown to be protective in cell cultures and murine models, was not effective for human skin explants. The ultrastructural analysis revealed that for preventing skin blistering at least desmosome number (as modulated by ERK) or keratin filament insertion (as modulated by PLC/Ca2+) need to be ameliorated. Other pathways such as p38MAPK regulate desmosome number, size, and keratin insertion indicating that they control desmosome assembly and disassembly on different levels. Taken together, studies in human skin delineate target mechanisms for the treatment of pemphigus patients. In addition, ultrastructural analysis supports defining the specific role of a given signaling molecule in desmosome turnover at ultrastructural level.
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9
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Fuchs M, Kugelmann D, Schlegel N, Vielmuth F, Waschke J. Desmoglein 2 can undergo Ca2+-dependent interactions with both desmosomal and classical cadherins including E-cadherin and N-cadherin. Biophys J 2022; 121:1322-1335. [PMID: 35183520 PMCID: PMC9034291 DOI: 10.1016/j.bpj.2022.02.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/23/2021] [Accepted: 02/15/2022] [Indexed: 11/02/2022] Open
Abstract
Desmoglein (Dsg) 2 is a ubiquitously expressed desmosomal cadherin. Particularly, it is present in all cell types forming desmosomes, including epithelial cells and cardiac myocytes and is upregulated in the autoimmune skin disease pemphigus. Thus, we here characterized the binding properties of Dsg2 in more detail using atomic force microscopy (AFM). Dsg2 exhibits homophilic interactions and also heterophilic interactions with the desmosomal cadherin desmocollin (Dsc) 2, and further with the classical cadherins E-cadherin (E-Cad) and N-cadherin (N-Cad), which may be relevant for cross talk between desmosomes and adherens junctions in epithelia and cardiac myocytes. We found that all homo- and heterophilic interactions were Ca2+-dependent. All binding forces observed are in the same force range, i.e., 30 to 40 pN, except for the Dsg2/E-Cad unbinding force, which with 45 pN is significantly higher. To further characterize the nature of the interactions, we used tryptophan, a critical amino acid required for trans-interaction, and a tandem peptide (TP) designed to cross-link Dsg isoforms. TP was sufficient to prevent the tryptophan-induced loss of Dsg2 interaction with the desmosomal cadherins Dsg2 and Dsc2; however, not with the classical cadherins E-Cad and N-Cad, indicating that the interaction modes of Dsg2 with desmosomal and classical cadherins differ. TP rescued the tryptophan-induced loss of Dsg2 binding on living enterocytes, suggesting that interaction with desmosomal cadherins may be more relevant. In summary, the data suggest that the ubiquitous desmosomal cadherin Dsg2 enables the cross talk with adherens junctions by interacting with multiple binding partners with implications for proper adhesive function in healthy and diseased states.
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Kaur B, Kerbrat J, Kho J, Kaler M, Kanatsios S, Cirillo N. Mechanism-based therapeutic targets of pemphigus vulgaris: A scoping review of pathogenic molecular pathways. Exp Dermatol 2021; 31:154-171. [PMID: 34435386 DOI: 10.1111/exd.14453] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/20/2021] [Accepted: 08/19/2021] [Indexed: 12/14/2022]
Abstract
Pemphigus vulgaris (PV) is a potentially fatal autoimmune blistering disease characterised by cell-cell detachment or acantholysis. The mechanisms which follow antibody (Ab) binding and culminate in acantholytic changes and skin/mucosal blistering have not been fully clarified. Current treatment strategies are not specific to PV pathophysiology and although life-saving, harbour considerable side effects. We aimed to systematically assess the molecules amenable to targeted treatments that follow Ab binding and are associated with PV acantholysis. The resulting scoping review was conducted under PRISMA-ScR guidelines with clear inclusion and exclusion criteria and focused specifically on kinases, caspases, proteases, hydrolytic enzymes and other molecules of interest postulated to take part in the pathophysiology of PV. The review process resulted in the identification of 882 articles, of which 56 were eligible for qualitative synthesis. From the included articles, the majority (n = 42) used PV-IgG as the pathogenic agent, mainly via in vitro (n = 16) and in vivo (n = 10) models. Twenty-five molecules were found to play a pathogenic role in PV, including uPA, ADAM10, EGFR, Src, PKC, cdk2, ERK, PLC, calmodulin, NOS, p38MAPK and caspase-3. Selective inhibition of these molecules resulted in varying degrees of reduction in acantholysis and blistering. The pathogenic molecules identified in this review represent potential candidates for clinical translation.
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Affiliation(s)
- Bavleen Kaur
- Melbourne Dental School, The University of Melbourne, Carlton, Victoria, Australia
| | - Jenna Kerbrat
- Melbourne Dental School, The University of Melbourne, Carlton, Victoria, Australia
| | - Jia Kho
- Melbourne Dental School, The University of Melbourne, Carlton, Victoria, Australia
| | - Manreet Kaler
- Melbourne Dental School, The University of Melbourne, Carlton, Victoria, Australia
| | - Stefanos Kanatsios
- Melbourne Dental School, The University of Melbourne, Carlton, Victoria, Australia
| | - Nicola Cirillo
- Melbourne Dental School, The University of Melbourne, Carlton, Victoria, Australia
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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: 28] [Impact Index Per Article: 9.3] [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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12
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Nili A, Salehi Farid A, Asgari M, Tavakolpour S, Mahmoudi H, Daneshpazhooh M. Current status and prospects for the diagnosis of pemphigus vulgaris. Expert Rev Clin Immunol 2021; 17:819-834. [PMID: 34162306 DOI: 10.1080/1744666x.2021.1945925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Introduction: Pemphigus vulgaris (PV) is an intraepidermal autoimmune bullous disease (AIBD) characterized by autoantibodies against desmosomal adhesion proteins, most commonly desmoglein (Dsg)3, leading to the suprabasal cleft formation and acantholysis.Areas covered: Direct immunofluorescence (DIF) and indirect immunofluorescence (IIF) studies display the intercellular deposition of IgG/C3 throughout the epidermis and presence of circulating autoantibodies respectively, as a net-like pattern. However, the target antigen remains unknown using immunofluorescence techniques. Thanks to the development of Dsg ELISA, using recombinant technology, circulating antibodies against Dsg1 and 3 could be detected sensitively. It is possible to differentiate PV from pemphigus foliaceus (PF) using this assay. BIOCHIP mosaic and multivariant ELISA are two novel serologic methods with the added value of the ability to screen several AIBDs simultaneously.Non-Dsg1/3 antigens are also involved in the pathogenesis of PV and investigated more deeply thanks to the protein microarrays technique. Additionally, patients with high values of anti-Dsg1/3 may be lesion-free, suggesting the presence of nonpathogenic autoantibodies.Expert opinion: Newer diagnostic methods to replace traditional techniques should possess high sensitivity and specificity and be widely available, noninvasive, and relatively cheap. The newly developed methods need to be further evaluated before being recommended for routine use.
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Affiliation(s)
- Ali Nili
- Department of Dermatology, Autoimmune Bullous Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Salehi Farid
- Department of Dermatology, Autoimmune Bullous Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Asgari
- Department of Pathology and Laboratory Medicine, Yosemite Pathology Medical Group, San Ramon Regional Medical Center, San Ramon, CA, USA
| | - Soheil Tavakolpour
- Department of Dermatology, Autoimmune Bullous Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Hamidreza Mahmoudi
- Department of Dermatology, Autoimmune Bullous Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Maryam Daneshpazhooh
- Department of Dermatology, Autoimmune Bullous Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran
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13
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Schmitt T, Egu DT, Walter E, Sigmund AM, Eichkorn R, Yazdi A, Schmidt E, Sárdy M, Eming R, Goebeler M, Waschke J. Ca 2+ signalling is critical for autoantibody-induced blistering of human epidermis in pemphigus. Br J Dermatol 2021; 185:595-604. [PMID: 33792909 DOI: 10.1111/bjd.20091] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2021] [Indexed: 02/06/2023]
Abstract
BACKGROUND Pemphigus is a severe bullous autoimmune skin disease. Pemphigus foliaceus (PF) is characterized by antidesmoglein (Dsg) 1 IgG causing epidermal blistering; mucosal pemphigus vulgaris (mPV) by anti-Dsg3 IgG inducing erosions in the mucosa; and mucocutaneous pemphigus vulgaris (PV) by affecting both, with autoantibodies targeting Dsg1 and Dsg3. OBJECTIVES To characterize the Ca2+ flux pathway and delineate its importance in pemphigus pathogenesis and clinical phenotypes caused by different antibody profiles. METHODS Immunoprecipitation, Ca2+ flux analysis, Western blotting, immunofluorescence staining, dissociation assays and a human skin ex vivo model were used. RESULTS PV IgG and PF IgG, but neither Dsg3-specific monoclonal antibody (AK23) nor mPV IgG, caused Ca2+ influx in primary human keratinocytes. Phosphatidylinositol 4-kinase α interacts with Dsg1 but not with Dsg3. Its downstream target - phospholipase-C-γ1 (PLC) - was activated by PV IgG and PF IgG but not AK23 or mPV IgG. PLC releases inositol 1,4,5-trisphosphate (IP3) causing IP3 receptor (IP3R) activation and Ca2+ flux from the endoplasmic reticulum into the cytosol, which stimulates Ca2+ release-activated channels (CRAC)-mediated Ca2+ influx. Inhibitors against PLC, IP3R and CRAC effectively blocked PV IgG and PF IgG-induced Ca2+ influx; ameliorated alterations of Dsg1 and Dsg3 localization, and reorganization of keratin and actin filaments; and inhibited loss of cell adhesion in vitro. Finally, inhibiting PLC or IP3R was protective against PV IgG-induced blister formation and redistribution of Dsg1 and Dsg3 in human skin ex vivo. CONCLUSIONS Ca2+ -mediated signalling is important for epidermal blistering and dependent on the autoantibody profile, which indicates different roles for signalling complexes organized by Dsg1 and Dsg3. Interfering with PLC and Ca2+ signalling may be a promising approach to treat epidermal manifestations of pemphigus.
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Affiliation(s)
- T Schmitt
- Ludwig-Maximilian-Universität München, Anatomische Anstalt, Lehrstuhl Anatomie I - Vegetative Anatomie, Pettenkoferstraße 11, München, D-80336, Germany
| | - D T Egu
- Ludwig-Maximilian-Universität München, Anatomische Anstalt, Lehrstuhl Anatomie I - Vegetative Anatomie, Pettenkoferstraße 11, München, D-80336, Germany
| | - E Walter
- Ludwig-Maximilian-Universität München, Anatomische Anstalt, Lehrstuhl Anatomie I - Vegetative Anatomie, Pettenkoferstraße 11, München, D-80336, Germany
| | - A M Sigmund
- Ludwig-Maximilian-Universität München, Anatomische Anstalt, Lehrstuhl Anatomie I - Vegetative Anatomie, Pettenkoferstraße 11, München, D-80336, Germany
| | - R Eichkorn
- Department of Dermatology, University Medical Center Tübingen, Eberhard Karls-University, Tübingen, Germany
| | - A Yazdi
- Department of Dermatology, University Medical Center Tübingen, Eberhard Karls-University, Tübingen, Germany.,Department of Dermatology, RWTH Aachen, Aachen, Germany
| | - E Schmidt
- Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck, Lübeck, 23562, Germany.,Department of Dermatology, University of Lübeck, Lübeck, 23562, Germany
| | - M Sárdy
- Clinic for Dermatology, Semmelweis University, Budapest, Hungary
| | - R Eming
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, Germany
| | - M Goebeler
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, 97080, Germany
| | - J Waschke
- Ludwig-Maximilian-Universität München, Anatomische Anstalt, Lehrstuhl Anatomie I - Vegetative Anatomie, Pettenkoferstraße 11, München, D-80336, Germany
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14
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Huang Y, Jedličková H, Cai Y, Rehman A, Gammon L, Ahmad US, Uttagomol J, Parkinson EK, Fortune F, Wan H. Oxidative Stress-Mediated YAP Dysregulation Contributes to the Pathogenesis of Pemphigus Vulgaris. Front Immunol 2021; 12:649502. [PMID: 33968042 PMCID: PMC8098436 DOI: 10.3389/fimmu.2021.649502] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 03/29/2021] [Indexed: 11/15/2022] Open
Abstract
Pemphigus Vulgaris (PV) is a life-threatening autoimmune disease manifested with blisters in the skin and mucosa and caused by autoantibodies against adhesion protein desmoglein-3 (Dsg3) expressed in epithelial membrane linings of these tissues. Despite many studies, the pathogenesis of PV remains incompletely understood. Recently we have shown Dsg3 plays a role in regulating the yes-associated protein (YAP), a co-transcription factor and mechanical sensor, and constraining reactive oxygen species (ROS). This study investigated the effect of PV sera as well as the anti-Dsg3 antibody AK23 on these molecules. We detected elevated YAP steady-state protein levels in PV cells surrounding blisters and perilesional regions and in keratinocytes treated with PV sera and AK23 with concomitant transient ROS overproduction. Cells treated with hydrogen peroxide also exhibited augmented nuclear YAP accompanied by reduction of Dsg3 and α-catenin, a negative regulator of YAP. As expected, transfection of α-catenin-GFP plasmid rendered YAP export from the nucleus evoked by hydrogen peroxide. In addition, suppression of total YAP was observed in hydrogen peroxide treated cells exposed to antioxidants with enhanced cell-cell adhesion being confirmed by decreased fragmentation in the dispase assay compared to hydrogen peroxide treatment alone. On the other hand, the expression of exogenous YAP disrupted intercellular junction assembly. In contrast, YAP depletion resulted in an inverse effect with augmented expression of junction assembly proteins, including Dsg3 and α-catenin capable of abolishing the effect of AK23 on Dsg3 expression. Finally, inhibition of other kinase pathways, including p38MAPK, also demonstrated suppression of YAP induced by hydrogen peroxide. Furthermore, antioxidant treatment of keratinocytes suppressed PV sera-induced total YAP accumulation. In conclusion, this study suggests that oxidative stress coupled with YAP dysregulation attributes to PV blistering, implying antioxidants may be beneficial in the treatment of PV.
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Affiliation(s)
- Yunying Huang
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, London, United Kingdom
| | - Hana Jedličková
- Department of Dermatology, St. Anna University Hospital, Brno, Czechia
| | - Yang Cai
- CB Joint MHNCRL, Hospital and School of Stomatology, Guizhou Medical University, Guiyang, China
| | - Ambreen Rehman
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, London, United Kingdom
| | - Luke Gammon
- Phenotypic Screening Facility, Blizard Institute, Barts and The London School of Medicine and Dentistry, London, United Kingdom
| | - Usama Sharif Ahmad
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, London, United Kingdom
| | - Jutamas Uttagomol
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, London, United Kingdom
| | - Eric Kenneth Parkinson
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, London, United Kingdom
| | - Farida Fortune
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, London, United Kingdom
| | - Hong Wan
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, London, United Kingdom
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15
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Sigmund AM, Steinert LS, Egu DT, Bayerbach FC, Waschke J, Vielmuth F. Dsg2 Upregulation as a Rescue Mechanism in Pemphigus. Front Immunol 2020; 11:581370. [PMID: 33193387 PMCID: PMC7655986 DOI: 10.3389/fimmu.2020.581370] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 09/28/2020] [Indexed: 12/20/2022] Open
Abstract
In pemphigus vulgaris (PV), autoantibodies directed against the desmosomal cadherin desmoglein (Dsg) 3 cause loss of intercellular adhesion. It is known that Dsg3 interactions are directly inhibited by autoantibody binding and that Dsg2 is upregulated in epidermis of PV patients. Here, we investigated whether heterophilic Dsg2-Dsg3 interactions occur and would modulate PV pathogenesis. Dsg2 was upregulated in PV patients’ biopsies and in a human ex vivo pemphigus skin model. Immunoprecipitation and cell-free atomic force microscopy (AFM) experiments demonstrated heterophilic Dsg2-Dsg3 interactions. Similarly, in Dsg3-deficient keratinocytes with severely disturbed intercellular adhesion Dsg2 was upregulated in the desmosome containing fraction. AFM revealed that Dsg2-Dsg3 heterophilic interactions showed binding frequency, strength, Ca2+-dependency and catch-bond behavior comparable to homophilic Dsg3-Dsg3 or homophilic Dsg2-Dsg2 interactions. However, heterophilic Dsg2-Dsg3 interactions had a longer lifetime compared to homophilic Dsg2-Dsg2 interactions and PV autoantibody-induced direct inhibition was significantly less pronounced for heterophilic Dsg2-Dsg3 interactions compared to homophilic Dsg3 interactions. In contrast, a monoclonal anti-Dsg2 inhibitory antibody reduced heterophilic Dsg2-Dsg3 and homophilic Dsg2-Dsg2 binding to the same degree and further impaired intercellular adhesion in Dsg3-deficient keratinocytes. Taken together, the data demonstrate that Dsg2 undergoes heterophilic interactions with Dsg3, which may attenuate autoantibody-induced loss of keratinocyte adhesion in pemphigus.
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Affiliation(s)
- Anna M Sigmund
- Department I, Faculty of Medicine, Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Letyfee S Steinert
- Department I, Faculty of Medicine, Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Desalegn T Egu
- Department I, Faculty of Medicine, Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Franziska C Bayerbach
- Department I, Faculty of Medicine, Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Jens Waschke
- Department I, Faculty of Medicine, Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Franziska Vielmuth
- Department I, Faculty of Medicine, Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich, Germany
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16
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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: 16] [Impact Index Per Article: 4.0] [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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17
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Hammers CM, Stanley JR. Recent Advances in Understanding Pemphigus and Bullous Pemphigoid. J Invest Dermatol 2020; 140:733-741. [DOI: 10.1016/j.jid.2019.11.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 10/29/2019] [Accepted: 11/01/2019] [Indexed: 12/11/2022]
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18
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Broussard JA, Jaiganesh A, Zarkoob H, Conway DE, Dunn AR, Espinosa HD, Janmey PA, Green KJ. Scaling up single-cell mechanics to multicellular tissues - the role of the intermediate filament-desmosome network. J Cell Sci 2020; 133:jcs228031. [PMID: 32179593 PMCID: PMC7097224 DOI: 10.1242/jcs.228031] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cells and tissues sense, respond to and translate mechanical forces into biochemical signals through mechanotransduction, which governs individual cell responses that drive gene expression, metabolic pathways and cell motility, and determines how cells work together in tissues. Mechanotransduction often depends on cytoskeletal networks and their attachment sites that physically couple cells to each other and to the extracellular matrix. One way that cells associate with each other is through Ca2+-dependent adhesion molecules called cadherins, which mediate cell-cell interactions through adherens junctions, thereby anchoring and organizing the cortical actin cytoskeleton. This actin-based network confers dynamic properties to cell sheets and developing organisms. However, these contractile networks do not work alone but in concert with other cytoarchitectural elements, including a diverse network of intermediate filaments. This Review takes a close look at the intermediate filament network and its associated intercellular junctions, desmosomes. We provide evidence that this system not only ensures tissue integrity, but also cooperates with other networks to create more complex tissues with emerging properties in sensing and responding to increasingly stressful environments. We will also draw attention to how defects in intermediate filament and desmosome networks result in both chronic and acquired diseases.
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Affiliation(s)
- Joshua A Broussard
- Departments of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
| | - Avinash Jaiganesh
- Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Hoda Zarkoob
- Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Daniel E Conway
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Alexander R Dunn
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Horacio D Espinosa
- Department of Mechanical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Paul A Janmey
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kathleen J Green
- Departments of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
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19
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Egu D, Sigmund A, Schmidt E, Spindler V, Walter E, Waschke J. A new
ex vivo
human oral mucosa model reveals that p38
MAPK
inhibition is not effective in preventing autoantibody‐induced mucosal blistering in pemphigus. Br J Dermatol 2019; 182:987-994. [DOI: 10.1111/bjd.18237] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2019] [Indexed: 02/06/2023]
Affiliation(s)
- D.T. Egu
- Chair of Vegetative Anatomy Institute of Anatomy Faculty of Medicine LMU Munich Germany
| | - A.M. Sigmund
- Chair of Vegetative Anatomy Institute of Anatomy Faculty of Medicine LMU Munich Germany
| | - E. Schmidt
- Lübeck Institute of Experimental Dermatology University of Lübeck LübeckGermany
- Department of Dermatology, Allergology and Venereology University of Lübeck Lübeck Germany
| | - V. Spindler
- Chair of Vegetative Anatomy Institute of Anatomy Faculty of Medicine LMU Munich Germany
- Department of Biomedicine University of Basel Basel Switzerland
| | - E. Walter
- Chair of Vegetative Anatomy Institute of Anatomy Faculty of Medicine LMU Munich Germany
| | - J. Waschke
- Chair of Vegetative Anatomy Institute of Anatomy Faculty of Medicine LMU Munich Germany
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20
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Fuchs M, Foresti M, Radeva MY, Kugelmann D, Keil R, Hatzfeld M, Spindler V, Waschke J, Vielmuth F. Plakophilin 1 but not plakophilin 3 regulates desmoglein clustering. Cell Mol Life Sci 2019; 76:3465-3476. [PMID: 30949721 PMCID: PMC11105395 DOI: 10.1007/s00018-019-03083-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 02/15/2019] [Accepted: 03/25/2019] [Indexed: 12/25/2022]
Abstract
Plakophilins (Pkp) are desmosomal plaque proteins crucial for desmosomal adhesion and participate in the regulation of desmosomal turnover and signaling. However, direct evidence that Pkps regulate clustering and molecular binding properties of desmosomal cadherins is missing. Here, keratinocytes lacking either Pkp1 or 3 in comparison to wild type (wt) keratinocytes were characterized with regard to their desmoglein (Dsg) 1- and 3-binding properties and their capability to induce Dsg3 clustering. As revealed by atomic force microscopy (AFM), both Pkp-deficient keratinocyte cell lines showed reduced membrane availability and binding frequency of Dsg1 and 3 at cell borders. Extracellular crosslinking and AFM cluster mapping demonstrated that Pkp1 but not Pkp3 is required for Dsg3 clustering. Accordingly, Dsg3 overexpression reconstituted cluster formation in Pkp3- but not Pkp1-deficient keratinocytes as shown by AFM and STED experiments. Taken together, these data demonstrate that both Pkp1 and 3 regulate Dsg membrane availability, whereas Pkp1 but not Pkp3 is required for Dsg3 clustering.
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Affiliation(s)
- Michael Fuchs
- Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-Universität Munich, Pettenkoferstr. 11, 80336, Munich, Germany
| | - Marco Foresti
- Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-Universität Munich, Pettenkoferstr. 11, 80336, Munich, Germany
| | - Mariya Y Radeva
- Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-Universität Munich, Pettenkoferstr. 11, 80336, Munich, Germany
| | - Daniela Kugelmann
- Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-Universität Munich, Pettenkoferstr. 11, 80336, Munich, Germany
| | - Rene Keil
- Division of Pathobiochemistry, Institute of Molecular Medicine, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Mechthild Hatzfeld
- Division of Pathobiochemistry, Institute of Molecular Medicine, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Volker Spindler
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Jens Waschke
- Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-Universität Munich, Pettenkoferstr. 11, 80336, Munich, Germany.
| | - Franziska Vielmuth
- Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-Universität Munich, Pettenkoferstr. 11, 80336, Munich, Germany.
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21
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Walter E, Vielmuth F, Wanuske MT, Seifert M, Pollmann R, Eming R, Waschke J. Role of Dsg1- and Dsg3-Mediated Signaling in Pemphigus Autoantibody-Induced Loss of Keratinocyte Cohesion. Front Immunol 2019; 10:1128. [PMID: 31178865 PMCID: PMC6543754 DOI: 10.3389/fimmu.2019.01128] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 05/03/2019] [Indexed: 12/13/2022] Open
Abstract
Pemphigus is an autoimmune dermatosis in which mucocutaneous blisters are induced primarily by autoantibodies against Desmoglein (Dsg) 1 and 3. Pemphigus vulgaris (PV) usually is associated with autoantibodies against Dsg3 whereas pemphigus foliaceus (PF) patients present autoantibodies against Dsg1. Several signaling pathways were proposed to cause loss of keratinocyte adhesion. However, relevance of different signaling pathways and role of Dsg1 and 3 to trigger signaling are not fully understood. Here, we show that Ca2+ chelation reduced PV-IgG- and PF-IgG-mediated loss of HaCaT keratinocyte cohesion whereas EGFR inhibition did not inhibit effects of PF-IgG. PV-IgG activated EGFR in a Src-dependent manner whereas both PV-IgG and PF-IgG caused Ca2+ influx independent of EGFR. ERK activation was Src-dependent in response to PV-IgG but not PF-IgG. To delineate the roles of Dsg isoforms to trigger signaling pathways, Dsg3- and Dsg2-deficient HaCaT keratinocyte cell lines were generated using CRISPR/Cas9. Dsg3- but not Dsg2-deficient cells were protected against PV-IgG-induced loss of cell adhesion. Ca2+ influx and ERK activation in response to PF-IgG were preserved in both cell lines.
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Affiliation(s)
- Elias Walter
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Franziska Vielmuth
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Marie-Therès Wanuske
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Matthias Seifert
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Robert Pollmann
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, Germany
| | - Rüdiger Eming
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, Germany
| | - Jens Waschke
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität München, Munich, Germany
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22
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Kugelmann D, Rötzer V, Walter E, Egu DT, Fuchs MT, Vielmuth F, Vargas-Robles H, Schnoor M, Hertl M, Eming R, Rottner K, Schmidt A, Spindler V, Waschke J. Role of Src and Cortactin in Pemphigus Skin Blistering. Front Immunol 2019; 10:626. [PMID: 31024527 PMCID: PMC6461052 DOI: 10.3389/fimmu.2019.00626] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 03/08/2019] [Indexed: 02/06/2023] Open
Abstract
Autoantibodies against desmoglein (Dsg) 1 and Dsg3 primarily cause blister formation in the autoimmune disease pemphigus vulgaris (PV). Src was proposed to contribute to loss of keratinocyte cohesion. However, the role and underlying mechanisms are unclear and were studied here. In keratinocytes, cell cohesion in response to autoantibodies was reduced in Src-dependent manner by two patient-derived PV-IgG fractions as well as by AK23 but not by a third PV-IgG fraction, although Src was activated by all autoantibodies. Loss of cell cohesion was progredient in a timeframe of 24 h and AK23, similar to PV-IgG, interfered with reconstitution of cell cohesion after Ca2+-switch, indicating that the autoantibodies also interfered with desmosome assembly. Dsg3 co-localized along cell contacts and interacted with the Src substrate cortactin. In keratinocytes isolated from cortactin-deficient mice, cell adhesion was impaired and Src-mediated inhibition of AK23-induced loss of cell cohesion for 24 h was significantly reduced compared to wild-type (wt) cells. Similarly, AK23 impaired reconstitution of cell adhesion was Src-dependent only in the presence of cortactin. Likewise, Src inhibition significantly reduced AK23-induced skin blistering in wt but not cortactin-deficient mice. These data suggest that the Src-mediated long-term effects of AK23 on loss of cell cohesion and skin blistering are dependent on cortactin-mediated desmosome assembly. However, in human epidermis PV-IgG-induced skin blistering and ultrastructural alterations of desmosomes were not affected by Src inhibition, indicating that Src may not be critical for skin blistering in intact human skin, at least when high levels of autoantibodies targeting Dsg1 are present.
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Affiliation(s)
- Daniela Kugelmann
- Chair of Vegetative Anatomy, Institute of Anatomy, Medical Faculty, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Vera Rötzer
- Chair of Vegetative Anatomy, Institute of Anatomy, Medical Faculty, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Elias Walter
- Chair of Vegetative Anatomy, Institute of Anatomy, Medical Faculty, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Desalegn Tadesse Egu
- Chair of Vegetative Anatomy, Institute of Anatomy, Medical Faculty, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Michael Tobias Fuchs
- Chair of Vegetative Anatomy, Institute of Anatomy, Medical Faculty, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Franziska Vielmuth
- Chair of Vegetative Anatomy, Institute of Anatomy, Medical Faculty, Ludwig-Maximilians-Universität München, Munich, Germany
| | | | - Michael Schnoor
- Department of Molecular Biomedicine, Cinvestav-IPN, Mexico City, Mexico
| | - Michael Hertl
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, Germany
| | - Rüdiger Eming
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, Germany
| | - Klemens Rottner
- Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.,Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ansgar Schmidt
- Instiute of Pathology, Philipps-Universität Marburg, Marburg, Germany
| | - Volker Spindler
- Chair of Vegetative Anatomy, Institute of Anatomy, Medical Faculty, Ludwig-Maximilians-Universität München, Munich, Germany.,Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Jens Waschke
- Chair of Vegetative Anatomy, Institute of Anatomy, Medical Faculty, Ludwig-Maximilians-Universität München, Munich, Germany
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23
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Waschke J. Desmogleins as signaling hubs regulating cell cohesion and tissue/organ function in skin and heart - EFEM lecture 2018. Ann Anat 2018; 226:96-100. [PMID: 30529571 DOI: 10.1016/j.aanat.2018.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 11/27/2018] [Indexed: 01/18/2023]
Abstract
Cell-cell contacts are crucial for intercellular cohesion and formation of endothelial and epithelial barriers. Desmosomes are the adhesive contacts providing mechanical strength to epithelial intercellular adhesion and therefore are most abundant in tissues subjected to high mechanical stress such as the epidermis and heart muscle. Desmogleins (Dsg) besides intercellular adhesion serve as signalling hubs regulating cell behaviour. In desmosomal diseases such as the autoimmune blistering skin disease pemphigus or arrhythmic cardiomyopathy (AC), which is caused by mutations of desmosomal components of cardiomyocyte intercalated discs, the adhesive and signalling functions of desmosomes are impaired. Therefore, our goal is to elucidate the mechanisms regulating adhesion of desmosomes in order to develop new strategies to treat desmosomal diseases. For pemphigus, we have provided evidence that intracellular signalling is required for loss of keratinocyte cohesion and have characterized a first disease-relevant adhesion receptor consisting of Dsg3 and p38MAPK. We propose that signalling patterns correlate with autoantibody profiles and thereby define the clinical phenotypes of pemphigus. Besides direct modulation of signalling pathways we have demonstrated that peptide-mediated crosslinking of Dsg molecules can abolish skin blistering in vivo. A similar approach may be effective to stabilize adhesion in cardiomyocytes of AC hearts. Since we observed that the adrenergic β1-receptor is localized at intercalated discs we evaluate signalling pathways regulating cardiomyocyte cohesion. With adrenergic signalling we have reported a first mechanism to stabilize desmosomal adhesion in intercalated discs and proposed a new function of the sympathicus in the heart we refer to as positive adhesiotropy.
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Affiliation(s)
- Jens Waschke
- Institute of Anatomy, Faculty of Medicine, LMU Munich, Pettenkoferstr. 11, 80336 Munich, Germany.
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24
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Schlögl E, Radeva MY, Vielmuth F, Schinner C, Waschke J, Spindler V. Keratin Retraction and Desmoglein3 Internalization Independently Contribute to Autoantibody-Induced Cell Dissociation in Pemphigus Vulgaris. Front Immunol 2018; 9:858. [PMID: 29922278 PMCID: PMC5996934 DOI: 10.3389/fimmu.2018.00858] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 04/06/2018] [Indexed: 01/12/2023] Open
Abstract
Pemphigus vulgaris (PV) is a potentially lethal autoimmune disease characterized by blister formation of the skin and mucous membranes and is caused by autoantibodies against desmoglein (Dsg) 1 and Dsg3. Dsg1 and Dsg3 are linked to keratin filaments in desmosomes, adhering junctions abundant in tissues exposed to high levels of mechanical stress. The binding of the autoantibodies leads to internalization of Dsg3 and a collapse of the keratin cytoskeleton-yet, the relevance and interdependence of these changes for loss of cell-cell adhesion and blistering is poorly understood. In live-cell imaging studies, loss of the keratin network at the cell periphery was detectable starting after 60 min of incubation with immunoglobulin G fractions of PV patients (PV-IgG). These rapid changes correlated with loss of cell-cell adhesion detected by dispase-based dissociation assays and were followed by a condensation of keratin filaments into thick bundles after several hours. Dsg3 internalization started at 90 min of PV-IgG treatment, thus following the early keratin changes. By inhibiting casein kinase 1 (CK-1), we provoked keratin alterations resembling the effects of PV-IgG. Although CK-1-induced loss of peripheral keratin network correlated with loss of cell cohesion and Dsg3 clustering in the membrane, it was not sufficient to trigger the internalization of Dsg3. However, additional incubation with PV-IgG was effective to promote Dsg3 loss at the membrane, indicating that Dsg3 internalization is independent from keratin alterations. Vice versa, inhibiting Dsg3 internalization did not prevent PV-IgG-induced keratin retraction and only partially rescued cell cohesion. Together, keratin changes appear very early after autoantibody binding and temporally overlap with loss of cell cohesion. These early alterations appear to be distinct from Dsg3 internalization, suggesting a crucial role for initial loss of cell cohesion in PV.
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Affiliation(s)
- Elisabeth Schlögl
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig Maximilian University of Munich, Munich, Germany
| | - Mariya Y Radeva
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig Maximilian University of Munich, Munich, Germany
| | - Franziska Vielmuth
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig Maximilian University of Munich, Munich, Germany
| | - Camilla Schinner
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig Maximilian University of Munich, Munich, Germany
| | - Jens Waschke
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig Maximilian University of Munich, Munich, Germany
| | - Volker Spindler
- Chair of Vegetative Anatomy, Faculty of Medicine, Institute of Anatomy, Ludwig Maximilian University of Munich, Munich, Germany.,Department of Biomedicine, University of Basel, Basel, Switzerland
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25
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Sajda T, Sinha AA. Autoantibody Signaling in Pemphigus Vulgaris: Development of an Integrated Model. Front Immunol 2018; 9:692. [PMID: 29755451 PMCID: PMC5932349 DOI: 10.3389/fimmu.2018.00692] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/21/2018] [Indexed: 01/10/2023] Open
Abstract
Pemphigus vulgaris (PV) is an autoimmune skin blistering disease effecting both cutaneous and mucosal epithelia. Blister formation in PV is known to result from the binding of autoantibodies (autoAbs) to keratinocyte antigens. The primary antigenic targets of pathogenic autoAbs are known to be desmoglein 3, and to a lesser extent, desmoglein 1, cadherin family proteins that partially comprise the desmosome, a protein structure responsible for maintaining cell adhesion, although additional autoAbs, whose role in blister formation is still unclear, are also known to be present in PV patients. Nevertheless, there remain large gaps in knowledge concerning the precise mechanisms through which autoAb binding induces blister formation. Consequently, the primary therapeutic interventions for PV focus on systemic immunosuppression, whose side effects represent a significant health risk to patients. In an effort to identify novel, disease-specific therapeutic targets, a multitude of studies attempting to elucidate the pathogenic mechanisms downstream of autoAb binding, have led to significant advancements in the understanding of autoAb-mediated blister formation. Despite this enhanced characterization of disease processes, a satisfactory explanation of autoAb-induced acantholysis still does not exist. Here, we carefully review the literature investigating the pathogenic disease mechanisms in PV and, taking into account the full scope of results from these studies, provide a novel, comprehensive theory of blister formation in PV.
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Affiliation(s)
- Thomas Sajda
- Department of Dermatology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Animesh A Sinha
- Department of Dermatology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
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26
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Yang R, Broussard JA, Green KJ, Espinosa HD. Techniques to stimulate and interrogate cell-cell adhesion mechanics. EXTREME MECHANICS LETTERS 2018; 20:125-139. [PMID: 30320194 PMCID: PMC6181239 DOI: 10.1016/j.eml.2017.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Cell-cell adhesions maintain the mechanical integrity of multicellular tissues and have recently been found to act as mechanotransducers, translating mechanical cues into biochemical signals. Mechanotransduction studies have primarily focused on focal adhesions, sites of cell-substrate attachment. These studies leverage technical advances in devices and systems interfacing with living cells through cell-extracellular matrix adhesions. As reports of aberrant signal transduction originating from mutations in cell-cell adhesion molecules are being increasingly associated with disease states, growing attention is being paid to this intercellular signaling hub. Along with this renewed focus, new requirements arise for the interrogation and stimulation of cell-cell adhesive junctions. This review covers established experimental techniques for stimulation and interrogation of cell-cell adhesion from cell pairs to monolayers.
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Affiliation(s)
- Ruiguo Yang
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, United States
- Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588, United States
| | - Joshua A. Broussard
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, United States
- Department of Dermatology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, United States
| | - Kathleen J. Green
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, United States
- Department of Dermatology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, United States
| | - Horacio D. Espinosa
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, United States
- Theoretical and Applied Mechanics Program, Northwestern University, Evanston, IL 60208, United States
- Institute for Cellular Engineering Technologies, Northwestern University, Evanston, IL 60208, United States
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27
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Vielmuth F, Spindler V, Waschke J. Atomic Force Microscopy Provides New Mechanistic Insights into the Pathogenesis of Pemphigus. Front Immunol 2018; 9:485. [PMID: 29643851 PMCID: PMC5883869 DOI: 10.3389/fimmu.2018.00485] [Citation(s) in RCA: 17] [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: 12/21/2017] [Accepted: 02/23/2018] [Indexed: 12/19/2022] Open
Abstract
Autoantibodies binding to the extracellular domains of desmoglein (Dsg) 3 and 1 are critical in the pathogenesis of pemphigus by mechanisms leading to impaired function of desmosomes and blister formation in the epidermis and mucous membranes. Desmosomes are highly organized protein complexes which provide strong intercellular adhesion. Desmosomal cadherins such as Dsgs, proteins of the cadherin superfamily which interact via their extracellular domains in Ca2+-dependent manner, are the transmembrane adhesion molecules clustered within desmosomes. Investigations on pemphigus cover a wide range of experimental approaches including biophysical methods. Especially atomic force microscopy (AFM) has recently been applied increasingly because it allows the analysis of native materials such as cultured cells and tissues under near-physiological conditions. AFM provides information about the mechanical properties of the sample together with detailed interaction analyses of adhesion molecules. With AFM, it was recently demonstrated that autoantibodies directly inhibit Dsg interactions on the surface of living keratinocytes, a phenomenon which has long been considered the main mechanism causing loss of cell cohesion in pemphigus. In addition, AFM allows to study how signaling pathways altered in pemphigus control binding properties of Dsgs. More general, AFM and other biophysical studies recently revealed the importance of keratin filaments for regulation of Dsg binding and keratinocyte mechanical properties. In this mini-review, we reevaluate AFM studies in pemphigus and keratinocyte research, recapitulate what is known about the interaction mechanisms of desmosomal cadherins and discuss the advantages and limitations of AFM in these regards.
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Affiliation(s)
| | | | - Jens Waschke
- Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
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28
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Vielmuth F, Walter E, Fuchs M, Radeva MY, Buechau F, Magin TM, Spindler V, Waschke J. Keratins Regulate p38MAPK-Dependent Desmoglein Binding Properties in Pemphigus. Front Immunol 2018; 9:528. [PMID: 29616033 PMCID: PMC5868517 DOI: 10.3389/fimmu.2018.00528] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 02/28/2018] [Indexed: 12/20/2022] Open
Abstract
Keratins are crucial for the anchorage of desmosomes. Severe alterations of keratin organization and detachment of filaments from the desmosomal plaque occur in the autoimmune dermatoses pemphigus vulgaris and pemphigus foliaceus (PF), which are mainly caused by autoantibodies against desmoglein (Dsg) 1 and 3. Keratin alterations are a structural hallmark in pemphigus pathogenesis and correlate with loss of intercellular adhesion. However, the significance for autoantibody-induced loss of intercellular adhesion is largely unknown. In wild-type (wt) murine keratinocytes, pemphigus autoantibodies induced keratin filament retraction. Under the same conditions, we used murine keratinocytes lacking all keratin filaments (KtyII k.o.) as a model system to dissect the role of keratins in pemphigus. KtyII k.o. cells show compromised intercellular adhesion without antibody (Ab) treatment, which was not impaired further by pathogenic pemphigus autoantibodies. Nevertheless, direct activation of p38MAPK via anisomycin further decreased intercellular adhesion indicating that cell cohesion was not completely abrogated in the absence of keratins. Direct inhibition of Dsg3, but not of Dsg1, interaction via pathogenic autoantibodies as revealed by atomic force microscopy was detectable in both cell lines demonstrating that keratins are not required for this phenomenon. However, PF-IgG shifted Dsg1-binding events from cell borders toward the free cell surface in wt cells. This led to a distribution pattern of Dsg1-binding events similar to KtyII k.o. cells under resting conditions. In keratin-deficient keratinocytes, PF-IgG impaired Dsg1-binding strength, which was not different from wt cells under resting conditions. In addition, pathogenic autoantibodies were capable of activating p38MAPK in both KtyII wt and k.o. cells, the latter of which already displayed robust p38MAPK activation under resting conditions. Since inhibition of p38MAPK blocked autoantibody-induced loss of intercellular adhesion in wt cells and restored baseline cell cohesion in keratin-deficient cells, we conclude that p38MAPK signaling is (i) critical for regulation of cell adhesion, (ii) regulated by keratins, and (iii) targets both keratin-dependent and -independent mechanisms.
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Affiliation(s)
- Franziska Vielmuth
- Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Elias Walter
- Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Michael Fuchs
- Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Mariya Y Radeva
- Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Fanny Buechau
- Division of Cell and Developmental Biology, Institute of Biology, Sächsische Inkubator für Klinische Translation (SIKT), University of Leipzig, Leipzig, Germany
| | - Thomas M Magin
- Division of Cell and Developmental Biology, Institute of Biology, Sächsische Inkubator für Klinische Translation (SIKT), University of Leipzig, Leipzig, Germany
| | - Volker Spindler
- Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Jens Waschke
- Faculty of Medicine, Institute of Anatomy, Ludwig-Maximilians-Universität München, Munich, Germany
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29
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Lotti R, Shu E, Petrachi T, Marconi A, Palazzo E, Quadri M, Lin A, O'Reilly LA, Pincelli C. Soluble Fas Ligand Is Essential for Blister Formation in Pemphigus. Front Immunol 2018. [PMID: 29535737 PMCID: PMC5834757 DOI: 10.3389/fimmu.2018.00370] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Pemphigus is a blistering disease characterized by pemphigus autoantibodies (PVIgG) directed mostly against desmogleins (Dsgs), resulting in the loss of keratinocyte adhesion (acantholysis). Yet, the mechanisms underlying blister formation remain to be clarified. We have shown previously that anti-Fas ligand (FasL) antibody (Ab) prevents PVIgG-induced caspase-8 activation and Dsg cleavage in human keratinocytes, and that sera from pemphigus patients contain abnormally increased levels of FasL. Here, we demonstrate that recombinant FasL induces the activation of caspases prior to Dsg degradation, and anti-FasL Ab prevents acantholysis in cultured keratinocytes. Moreover, the silencing of FasL reduces PVIgG-induced caspase-8 activation and Dsg3 cleavage. Following injection of PVIgG into mice, FasL is upregulated at 1–3 h and is followed by caspase-8-mediated keratinocyte apoptosis, before blister formation. The administration of anti-FasL Ab after PVIgG injection blocks blister formation in mice. Furthermore, we injected PVIgG into two different gene-targeted mutant mice that selectively lack either secreted soluble FasL (sFasL), FasLΔs/Δs mice, or the membrane-bound form of FasL (mFasL), FasLΔm/Δm mice. After PVIgG treatment, blisters are only visible in FasLΔm/Δm animals, lacking mFasL, but still producing sFasL, similar to wild-type (C57BL/6) animals. By contrast, a significant decrease in the relative acantholytic area is observed in the FasLΔs/Δs animals. These results demonstrate that soluble FasL plays a crucial role in the mechanisms of blister formation, and blockade of FasL could be an effective therapeutic approach for pemphigus.
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Affiliation(s)
- Roberta Lotti
- Laboratory of Cutaneous Biology, Department of Surgical, Medical, Dental and Morphological Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - En Shu
- Laboratory of Cutaneous Biology, Department of Surgical, Medical, Dental and Morphological Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Tiziana Petrachi
- Laboratory of Cutaneous Biology, Department of Surgical, Medical, Dental and Morphological Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Alessandra Marconi
- Laboratory of Cutaneous Biology, Department of Surgical, Medical, Dental and Morphological Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Elisabetta Palazzo
- Laboratory of Cutaneous Biology, Department of Surgical, Medical, Dental and Morphological Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Marika Quadri
- Laboratory of Cutaneous Biology, Department of Surgical, Medical, Dental and Morphological Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Ann Lin
- Molecular Genetics of Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Lorraine A O'Reilly
- Molecular Genetics of Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, VIC, Australia
| | - Carlo Pincelli
- Laboratory of Cutaneous Biology, Department of Surgical, Medical, Dental and Morphological Sciences, University of Modena and Reggio Emilia, Modena, Italy
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30
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Spindler V, Waschke J. Pemphigus-A Disease of Desmosome Dysfunction Caused by Multiple Mechanisms. Front Immunol 2018; 9:136. [PMID: 29449846 PMCID: PMC5799217 DOI: 10.3389/fimmu.2018.00136] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 01/16/2018] [Indexed: 02/01/2023] Open
Abstract
Pemphigus is a severe autoimmune-blistering disease of the skin and mucous membranes caused by autoantibodies reducing desmosomal adhesion between epithelial cells. Autoantibodies against the desmosomal cadherins desmogleins (Dsgs) 1 and 3 as well as desmocollin 3 were shown to be pathogenic, whereas the role of other antibodies is unclear. Dsg3 interactions can be directly reduced by specific autoantibodies. Autoantibodies also alter the activity of signaling pathways, some of which regulate cell cohesion under baseline conditions and alter the turnover of desmosomal components. These pathways include Ca2+, p38MAPK, PKC, Src, EGFR/Erk, and several others. In this review, we delineate the mechanisms relevant for pemphigus pathogenesis based on the histology and the ultrastructure of patients’ lesions. We then dissect the mechanisms which can explain the ultrastructural hallmarks detectable in pemphigus patient skin. Finally, we reevaluate the concept that the spectrum of mechanisms, which induce desmosome dysfunction upon binding of pemphigus autoantibodies, finally defines the clinical phenotype.
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Affiliation(s)
- Volker Spindler
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Jens Waschke
- Faculty of Medicine, Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany
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31
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Ahmed AR, Carrozzo M, Caux F, Cirillo N, Dmochowski M, Alonso AE, Gniadecki R, Hertl M, López-Zabalza MJ, Lotti R, Pincelli C, Pittelkow M, Schmidt E, Sinha AA, Sprecher E, Grando SA. Monopathogenic vs multipathogenic explanations of pemphigus pathophysiology. Exp Dermatol 2018; 25:839-846. [PMID: 27305362 DOI: 10.1111/exd.13106] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2016] [Indexed: 01/31/2023]
Abstract
This viewpoint highlights major, partly controversial concepts about the pathogenesis of pemphigus. The monopathogenic theory explains intra-epidermal blistering through the "desmoglein (Dsg) compensation" hypothesis, according to which an antibody-dependent disabling of Dsg 1- and/or Dsg 3-mediated cell-cell attachments of keratinocytes (KCs) is sufficient to disrupt epidermal integrity and cause blistering. The multipathogenic theory explains intra-epidermal blistering through the "multiple hit" hypothesis stating that a simultaneous and synchronized inactivation of the physiological mechanisms regulating and/or mediating intercellular adhesion of KCs is necessary to disrupt epidermal integrity. The major premise for a multipathogenic theory is that a single type of autoantibody induces only reversible changes, so that affected KCs can recover due to a self-repair. The damage, however, becomes irreversible when the salvage pathway and/or other cell functions are altered by a partnering autoantibody and/or other pathogenic factors. Future studies are needed to (i) corroborate these findings, (ii) characterize in detail patient populations with non-Dsg-specific autoantibodies, and (iii) determine the extent of the contribution of non-Dsg antibodies in disease pathophysiology.
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Affiliation(s)
- A Razzaque Ahmed
- Department of Dermatology of Tufts University and Center for Blistering Diseases, Boston, MA, USA
| | - Marco Carrozzo
- School of Dental Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne, UK
| | - Frédéric Caux
- Department of Dermatology, University Paris 13, Avicenne Hospital, APHP, Bobigny, France
| | - Nicola Cirillo
- Melbourne Dental School and Oral Health CRC, The University of Melbourne, Melbourne, Vic., Australia
| | - Marian Dmochowski
- Autoimmune Blistering Dermatoses Section, Department of Dermatology, Poznan University of Medical Sciences, Poznan, Poland
| | - Agustín España Alonso
- Department of Dermatology, School of Medicine, University Clinic of Navarra, University of Navarra, Navarra, Spain
| | - Robert Gniadecki
- Division of Dermatology, University of Alberta, Edmonton, AB, Canada
| | - Michael Hertl
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | | | - Roberta Lotti
- Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy
| | - Carlo Pincelli
- Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy
| | - Mark Pittelkow
- Department of Dermatology, Mayo Clinic, Scottsdale, AZ, USA
| | - Enno Schmidt
- Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck, Lübeck, Germany
| | - Animesh A Sinha
- Department of Dermatology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Eli Sprecher
- Department of Dermatology, Tel Aviv Medical Center, Tel Aviv, Israel
| | - Sergei A Grando
- Institute for Immunology and Departments of Dermatology and Biological Chemistry, University of California, Irvine, CA, USA.
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32
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Egu DT, Walter E, Spindler V, Waschke J. Inhibition of p38MAPK signalling prevents epidermal blistering and alterations of desmosome structure induced by pemphigus autoantibodies in human epidermis. Br J Dermatol 2017; 177:1612-1618. [PMID: 28600798 DOI: 10.1111/bjd.15721] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2017] [Indexed: 01/01/2023]
Abstract
BACKGROUND Pemphigus vulgaris (PV) is a skin blistering disease caused by autoantibodies targeting the desmosomal adhesion proteins desmoglein (Dsg) 3 and 1. The mechanisms underlying pemphigus skin blistering are not fully elucidated but p38 mitogen-activated protein kinase (p38MAPK) activation is one of the signalling events necessary for full loss of cell cohesion. However, it is unclear whether ultrastructural hallmarks of desmosome morphology as observed in patients' lesions are mediated by p38MAPK signalling. OBJECTIVES In this study, we tested the relevance of p38MAPK for blister formation and the ultrastructural changes induced by PV autoantibodies in human skin. METHODS Human skin samples were injected with IgG fractions of one patient suffering from mucocutaneous PV (mcPV-IgG), one from mucosal-dominant PV (mdPV-IgG) or AK23, a pathogenic monoclonal Dsg3 antibody derived from a pemphigus mouse model. Samples were processed for histological and electron microscopy analyses. RESULTS mcPV-IgG and AK23 but not mdPV-IgG reduced desmosome size, caused interdesmosomal widening and formation of split desmosomes, and altered keratin filament insertion. In contrast, full epidermal blister formation and lower desmosome number were evident in tissue samples exposed to mcPV-IgG only. Pharmacological inhibition of p38MAPK blunted the reduction of desmosome number and size, ameliorated interdesmosomal widening and loss of keratin insertion and prevented mcPV-IgG-induced blister formation. CONCLUSIONS Our data demonstrate that blistering can be prevented by inhibition of p38MAPK in the human epidermis. Moreover, typical morphological alterations induced by mcPV-IgG such as interdesmosomal widening and the reduction of desmosome size at least in part require p38MAPK signalling.
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Affiliation(s)
- D T Egu
- Department I, Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität (LMU), München, D-80336, Germany
| | - E Walter
- Department I, Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität (LMU), München, D-80336, Germany
| | - V Spindler
- Department I, Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität (LMU), München, D-80336, Germany
| | - J Waschke
- Department I, Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität (LMU), München, D-80336, Germany
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Spindler V, Eming R, Schmidt E, Amagai M, Grando S, Jonkman MF, Kowalczyk AP, Müller EJ, Payne AS, Pincelli C, Sinha AA, Sprecher E, Zillikens D, Hertl M, Waschke J. Mechanisms Causing Loss of Keratinocyte Cohesion in Pemphigus. J Invest Dermatol 2017; 138:32-37. [PMID: 29037765 DOI: 10.1016/j.jid.2017.06.022] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Revised: 06/20/2017] [Accepted: 06/21/2017] [Indexed: 11/28/2022]
Abstract
The autoimmune blistering skin disease pemphigus is caused by IgG autoantibodies against desmosomal cadherins, but the precise mechanisms are in part a matter of controversial discussions. This review focuses on the currently existing models of the disease and highlights the relevance of desmoglein-specific versus nondesmoglein autoantibodies, the contribution of nonautoantibody factors, and the mechanisms leading to cell dissociation and blister formation in response to autoantibody binding. As the review brings together the majority of laboratories currently working on pemphigus pathogenesis, it aims to serve as a solid basis for further investigations for the entire field.
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Affiliation(s)
- Volker Spindler
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich, Germany.
| | - Rüdiger Eming
- Department of Dermatology, University of Marburg, Marburg, Germany
| | - Enno Schmidt
- Department of Dermatology, University of Lübeck, Lübeck, Germany; Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck, Lübeck, Germany
| | - Masayuki Amagai
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan
| | - Sergei Grando
- Institute for Immunology and Departments of Dermatology and Biological Chemistry, University of California, Irvine, California, USA
| | - Marcel F Jonkman
- Department of Dermatology, University Medical Centre Groningen, University of Groningen, Groningen, the Netherlands
| | - Andrew P Kowalczyk
- Departments of Cell Biology and Dermatology, Emory University, Atlanta, Georgia, USA
| | - Eliane J Müller
- Vetsuisse Faculty, Molecular Dermatology and Stem Cell Research, Institute of Animal Pathology, Bern, Switzerland; Vetsuisse Faculty, DermFocus, Bern, Switzerland; Department of Dermatology, University Hospital of Bern, Bern, Switzerland
| | - Aimee S Payne
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Carlo Pincelli
- Laboratory of Cutaneous Biology, University of Modena and Reggio Emilia, Modena, Italy
| | - Animesh A Sinha
- Department of Dermatology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, USA
| | - Eli Sprecher
- Department of Dermatology, Tel Aviv Medical Center, Tel Aviv, Israel
| | - Detlef Zillikens
- Department of Dermatology, University of Lübeck, Lübeck, Germany
| | - Michael Hertl
- Department of Dermatology, University of Marburg, Marburg, Germany
| | - Jens Waschke
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich, Germany.
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Vielmuth F, Wanuske MT, Radeva MY, Hiermaier M, Kugelmann D, Walter E, Buechau F, Magin TM, Waschke J, Spindler V. Keratins Regulate the Adhesive Properties of Desmosomal Cadherins through Signaling. J Invest Dermatol 2017; 138:121-131. [PMID: 28899688 DOI: 10.1016/j.jid.2017.08.033] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 07/10/2017] [Accepted: 08/06/2017] [Indexed: 11/17/2022]
Abstract
Tightly controlled intercellular adhesion is crucial for the integrity and function of the epidermis. The keratin filament cytoskeleton anchors desmosomes, supramolecular complexes required for strong intercellular adhesion. We tested whether keratin filaments control cell adhesion by regulating the adhesive properties of desmosomal cadherins such as desmoglein (Dsg) 3. Atomic force microscopy and fluorescence recovery after photobleaching experiments showed reduced Dsg3 adhesive forces and membrane stability in murine keratinocytes lacking all keratin filaments. Impairment of the actin cytoskeleton also resulted in decreased Dsg3 immobilization but did not affect Dsg3 binding properties, indicating that the latter are exclusively controlled by keratins. Reduced binding forces were dependent on p38 mitogen-activated protein kinase activity, which was deregulated in keratin-deficient cells. In contrast, inhibition of protein kinase C signaling, which is known to be controlled by keratins, promoted and spatially stabilized Dsg3-mediated interactions in the membrane. These results show a previously unreported mechanism for how keratins stabilize intercellular adhesion on the level of single desmosomal adhesion molecules.
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Affiliation(s)
- Franziska Vielmuth
- Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Marie-Therès Wanuske
- Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Mariya Y Radeva
- Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Matthias Hiermaier
- Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Daniela Kugelmann
- Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Elias Walter
- Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Fanny Buechau
- Institute of Biology and Translational Center for Regenerative Medicine, Sächsischer Inkubator für klinische Translation, University of Leipzig, Leipzig, Germany
| | - Thomas M Magin
- Institute of Biology and Translational Center for Regenerative Medicine, Sächsischer Inkubator für klinische Translation, University of Leipzig, Leipzig, Germany
| | - Jens Waschke
- Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany.
| | - Volker Spindler
- Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany.
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35
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Cipolla GA, Park JK, Lavker RM, Petzl-Erler ML. Crosstalk between Signaling Pathways in Pemphigus: A Role for Endoplasmic Reticulum Stress in p38 Mitogen-Activated Protein Kinase Activation? Front Immunol 2017; 8:1022. [PMID: 28928733 PMCID: PMC5591886 DOI: 10.3389/fimmu.2017.01022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 08/08/2017] [Indexed: 12/18/2022] Open
Abstract
Pemphigus consists of a group of chronic blistering skin diseases mediated by autoantibodies (autoAbs). The dogma that pemphigus is caused by keratinocyte dissociation (acantholysis) as a distinctive and direct consequence of the presence of autoAb targeting two main proteins of the desmosome—desmoglein (DSG) 1 and/or DSG3—has been put to the test. Several outside-in signaling events elicited by pemphigus autoAb in keratinocytes have been described, among which stands out p38 mitogen-activated protein kinase (p38 MAPK) engagement and its apoptotic effect on keratinocytes. The role of apoptosis in the disease is, however, debatable, to an extent that it may not be a determinant event for the occurrence of acantholysis. Also, it has been verified that compromised DSG trans-interaction does not lead to keratinocyte dissociation when p38 MAPK is inhibited. These examples of conflicting results have been followed by recent work revealing an important role for endoplasmic reticulum (ER) stress in pemphigus’ pathogenesis. ER stress is known to activate the p38 MAPK pathway, and vice versa. However, this relationship has not yet been studied in the context of activated signaling pathways in pemphigus. Therefore, by reviewing and hypothetically connecting the role(s) of ER stress and p38 MAPK pathway in pemphigus, we highlight the importance of elucidating the crosstalk between all activated signaling pathways, which may in turn contribute for a better understanding of the role of apoptosis in the disease and a better management of this life-threatening condition.
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Affiliation(s)
- Gabriel A Cipolla
- Department of Genetics, Federal University of Paraná, Curitiba, Brazil.,CAPES Foundation, Ministry of Education of Brazil, Brasília, Brazil
| | - Jong Kook Park
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States.,Department of Biomedical Science and Research, Institute for Bioscience and Biotechnology, Hallym University, Chuncheon, South Korea
| | - Robert M Lavker
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
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Desmoglein 2 regulates the intestinal epithelial barrier via p38 mitogen-activated protein kinase. Sci Rep 2017; 7:6329. [PMID: 28740231 PMCID: PMC5524837 DOI: 10.1038/s41598-017-06713-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 06/16/2017] [Indexed: 01/18/2023] Open
Abstract
Intestinal epithelial barrier properties are maintained by a junctional complex consisting of tight junctions (TJ), adherens junctions (AJ) and desmosomes. Desmoglein 2 (Dsg2), an adhesion molecule of desmosomes and the only Dsg isoform expressed in enterocytes, is required for epithelial barrier properties and may contribute to barrier defects in Crohn’s disease. Here, we identified extradesmosomal Dsg2 on the surface of polarized enterocytes by Triton extraction, confocal microscopy, SIM and STED. Atomic force microscopy (AFM) revealed Dsg2-specific binding events along the cell border on the surface of enterocytes with a mean unbinding force of around 30pN. Binding events were blocked by an inhibitory antibody targeting Dsg2 which under same conditions activated p38MAPK but did not reduce cell cohesion. In enterocytes deficient for Dsg2, p38MAPK activity was reduced and both barrier integrity and reformation were impaired. Dsc2 rescue did not restore p38MAPK activity indicating that Dsg2 is required. Accordingly, direct activation of p38MAPK in Dsg2-deficient cells enhanced barrier reformation demonstrating that Dsg2-mediated activation of p38MAPK is crucial for barrier function. Collectively, our data show that Dsg2, beside its adhesion function, regulates intestinal barrier function via p38MAPK signalling. This is in contrast to keratinocytes and points towards tissue-specific signalling functions of desmosomal cadherins.
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37
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Walter E, Vielmuth F, Rotkopf L, Sárdy M, Horváth ON, Goebeler M, Schmidt E, Eming R, Hertl M, Spindler V, Waschke J. Different signaling patterns contribute to loss of keratinocyte cohesion dependent on autoantibody profile in pemphigus. Sci Rep 2017; 7:3579. [PMID: 28620161 PMCID: PMC5472593 DOI: 10.1038/s41598-017-03697-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 05/02/2017] [Indexed: 12/19/2022] Open
Abstract
Pemphigus is an autoimmune blistering skin disease caused primarily by autoantibodies against desmoglein (Dsg)1 and 3. Here, we characterized the mechanisms engaged by pemphigus IgG from patients with different clinical phenotypes and autoantibody profiles. All pemphigus vulgaris (PV) and pemphigus foliaceus (PF) IgG and AK23, a monoclonal mouse antibody against Dsg3, caused loss of cell cohesion, cytokeratin retraction and p38MAPK activation. Strong alterations in Dsg3 distribution were caused by mucosal (aDsg3 antibodies), mucocutaneous (aDsg1 + aDsg3) as well as atypical (aDsg3) PV-IgG. All PV-IgG fractions and AK23 compromised Dsg3 but not Dsg1 binding and enhanced Src activity. In contrast, rapid Ca2+ influx and Erk activation were induced by mucocutaneous PV-IgG and pemphigus foliaceus (PF) IgG (aDsg1) whereas cAMP was increased by mucosal and mucocutaneous PV-IgG only. Selective inhibition of p38MAPK, Src or PKC blocked loss of keratinocyte cohesion in response to all autoantibody fractions whereas Erk inhibition was protective against mucocutaneous PV-IgG and PF-IgG only. These results demonstrate that signaling patterns parallel the clinical phenotype as some mechanisms involved in loss of cell cohesion are caused by antibodies targeting Dsg3 whereas others correlate with autoantibodies against Dsg1. The concept of key desmosome regulators may explain observations from several experimental models of pemphigus.
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Affiliation(s)
- Elias Walter
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität München, Munich, 80336, Germany
| | - Franziska Vielmuth
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität München, Munich, 80336, Germany
| | - Lukas Rotkopf
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität München, Munich, 80336, Germany
| | - Miklós Sárdy
- Department of Dermatology and Allergology, Ludwig-Maximilians-Universität München, Munich, 80336, Germany
| | - Orsolya N Horváth
- Department of Dermatology and Allergology, Ludwig-Maximilians-Universität München, Munich, 80336, Germany
| | - Matthias Goebeler
- Department of Dermatology, Venerology and Allergology, University Hospital Würzburg, Würzburg, 97080, Germany
| | - Enno Schmidt
- Lübeck Institute of Experimental Dermatology (Lied), University of Lübeck, Lübeck, 23562, Germany
| | - Rüdiger Eming
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, 35037, Germany
| | - Michael Hertl
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Marburg, 35037, Germany
| | - Volker Spindler
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität München, Munich, 80336, Germany.
| | - Jens Waschke
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität München, Munich, 80336, Germany.
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Ludwig RJ, Vanhoorelbeke K, Leypoldt F, Kaya Z, Bieber K, McLachlan SM, Komorowski L, Luo J, Cabral-Marques O, Hammers CM, Lindstrom JM, Lamprecht P, Fischer A, Riemekasten G, Tersteeg C, Sondermann P, Rapoport B, Wandinger KP, Probst C, El Beidaq A, Schmidt E, Verkman A, Manz RA, Nimmerjahn F. Mechanisms of Autoantibody-Induced Pathology. Front Immunol 2017; 8:603. [PMID: 28620373 PMCID: PMC5449453 DOI: 10.3389/fimmu.2017.00603] [Citation(s) in RCA: 309] [Impact Index Per Article: 44.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 05/08/2017] [Indexed: 12/22/2022] Open
Abstract
Autoantibodies are frequently observed in healthy individuals. In a minority of these individuals, they lead to manifestation of autoimmune diseases, such as rheumatoid arthritis or Graves' disease. Overall, more than 2.5% of the population is affected by autoantibody-driven autoimmune disease. Pathways leading to autoantibody-induced pathology greatly differ among different diseases, and autoantibodies directed against the same antigen, depending on the targeted epitope, can have diverse effects. To foster knowledge in autoantibody-induced pathology and to encourage development of urgently needed novel therapeutic strategies, we here categorized autoantibodies according to their effects. According to our algorithm, autoantibodies can be classified into the following categories: (1) mimic receptor stimulation, (2) blocking of neural transmission, (3) induction of altered signaling, triggering uncontrolled (4) microthrombosis, (5) cell lysis, (6) neutrophil activation, and (7) induction of inflammation. These mechanisms in relation to disease, as well as principles of autoantibody generation and detection, are reviewed herein.
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Affiliation(s)
- Ralf J. Ludwig
- Lübeck Institute of Experimental Dermatology, University of Lübeck, Lübeck, Germany
| | - Karen Vanhoorelbeke
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | - Frank Leypoldt
- Neuroimmunology, Institute of Clinical Chemistry, University Hospital Schleswig-Holstein, Kiel, Germany
- Neuroimmunology, Institute of Clinical Chemistry, University Hospital Schleswig-Holstein, Lübeck, Germany
- Department of Neurology, University of Kiel, Kiel, Germany
| | - Ziya Kaya
- Department of Internal Medicine III, University of Heidelberg, Heidelberg, Germany
| | - Katja Bieber
- Lübeck Institute of Experimental Dermatology, University of Lübeck, Lübeck, Germany
| | - Sandra M. McLachlan
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Medical Center, UCLA School of Medicine, Los Angeles, CA, United States
| | - Lars Komorowski
- Institute for Experimental Immunology, Affiliated to Euroimmun AG, Lübeck, Germany
| | - Jie Luo
- Department of Neuroscience, University of Pennsylvania Medical School, Philadelphia, PA, United States
| | | | | | - Jon M. Lindstrom
- Department of Neuroscience, University of Pennsylvania Medical School, Philadelphia, PA, United States
| | - Peter Lamprecht
- Department of Rheumatology, University of Lübeck, Lübeck, Germany
| | - Andrea Fischer
- Department of Internal Medicine III, University of Heidelberg, Heidelberg, Germany
| | | | - Claudia Tersteeg
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | | | - Basil Rapoport
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Medical Center, UCLA School of Medicine, Los Angeles, CA, United States
| | - Klaus-Peter Wandinger
- Department of Neurology, Institute of Clinical Chemistry, University Medical-Centre Schleswig-Holstein, Lübeck, Germany
| | - Christian Probst
- Institute for Experimental Immunology, Affiliated to Euroimmun AG, Lübeck, Germany
| | - Asmaa El Beidaq
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Enno Schmidt
- Lübeck Institute of Experimental Dermatology, University of Lübeck, Lübeck, Germany
| | - Alan Verkman
- Department of Medicine, University of California, San Francisco, CA, United States
- Department of Physiology, University of California, San Francisco, CA, United States
| | - Rudolf A. Manz
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Falk Nimmerjahn
- Department of Biology, Institute of Genetics, University of Erlangen-Nuremberg, Erlangen, Germany
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Schmidt E, Spindler V, Eming R, Amagai M, Antonicelli F, Baines JF, Belheouane M, Bernard P, Borradori L, Caproni M, Di Zenzo G, Grando S, Harman K, Jonkman MF, Koga H, Ludwig RJ, Kowalczyk AP, Müller EJ, Nishie W, Pas H, Payne AS, Sadik CD, Seppänen A, Setterfield J, Shimizu H, Sinha AA, Sprecher E, Sticherling M, Ujiie H, Zillikens D, Hertl M, Waschke J. Meeting Report of the Pathogenesis of Pemphigus and Pemphigoid Meeting in Munich, September 2016. J Invest Dermatol 2017; 137:1199-1203. [PMID: 28390814 DOI: 10.1016/j.jid.2017.01.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 01/05/2017] [Indexed: 02/07/2023]
Abstract
Autoimmune blistering diseases are a heterogeneous group of about a dozen complex disorders that are characterized by intraepidermal (pemphigus) and subepidermal blistering (pemphigoid diseases and dermatitis herpetiformis). The Pathogenesis of Pemphigus and Pemphigoid Meeting, organized by the Departments of Dermatology in Lübeck and Marburg and the Institute of Anatomy and Cell Biology, Munich, was held in September 2016 in Munich. The meeting brought together basic scientists and clinicians from all continents dedicating their work to autoimmune blistering diseases. Considerable advances have been made in describing incidences and prevalences of these diseases and linking comorbidities with autoantibody reactivities and clinical variants, for example, dipeptidyl peptidase-IV inhibitor-associated noninflammatory bullous pemphigoid. Although new entities are still being described, diagnosis of most autoimmune blistering diseases can now be achieved using standardized and widely available serological test systems. Various experimental mouse models of pemphigus and pemphigoid disease are increasingly being used to understand mechanisms of central and peripheral tolerance and to evaluate more specific treatment approaches for these disorders, such as molecules that target autoreactive T and B cells and anti-inflammatory mediators, that is, dimethyl fumarate, phosphodiesterase 4, and leukotriene B4 inhibitors in pemphigoid disorders, and chimeric antigen receptor T cells in pemphigus. Very recent experimental data about the immunopathology and the determinants of autoantibody formation and keratinocyte susceptibility in pemphigus were discussed. With regard to cellular mechanisms leading to the loss of cell-cell adhesion, new ideas were shared in the field of signal transduction. Major steps were taken to put the various partly contradictory and controversial findings about the effects of pemphigus autoantibodies and other inflammatory mediators into perspective and broaden our view of the complex pathophysiology of this disease. Finally, two investigator-initiated multicenter trials highlighted doxycycline and dapsone as valuable medications in the treatment of bullous pemphigoid.
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Affiliation(s)
- Enno Schmidt
- Department of Dermatology, University of Lübeck, Lübeck, Germany; Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck, Lübeck, Germany.
| | - Volker Spindler
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Rüdiger Eming
- Department of Dermatology, Philipps University, Marburg, Germany
| | | | | | - John F Baines
- Max Planck Institute for Evolutionary Biology, Plön, and Institute for Experimental Medicine, University of Kiel, Kiel, Germany
| | - Meriem Belheouane
- Max Planck Institute for Evolutionary Biology, Plön, and Institute for Experimental Medicine, University of Kiel, Kiel, Germany
| | | | - Luca Borradori
- Department of Dermatology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Marzia Caproni
- Department of Dermatology, University of Florence, Florence, Italy
| | - Giovanni Di Zenzo
- Molecular and Cell Biology Laboratory, Istituto Dermopatico dell'Immacolata (IDI)-IRCCS FLMM, Rome, Italy
| | - Sergei Grando
- Institute for Immunology and Departments of Dermatology and Biological Chemistry, University of California, Irvine, California, USA
| | - Karen Harman
- Department of Dermatology, University Hospitals of Leicester, Leicester, UK
| | - Marcel F Jonkman
- Department of Dermatology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Hiroshi Koga
- Department of Dermatology, Kurume University School of Medicine, Kurume, Japan
| | - Ralf J Ludwig
- Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck, Lübeck, Germany
| | - Andrew P Kowalczyk
- Departments of Cell Biology and Dermatology, Emory University, Atlanta, Georgia, USA
| | - Eliane J Müller
- Department of Dermatology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Institute of Animal Pathology, University of Bern, Switzerland
| | - Wataru Nishie
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Hendri Pas
- Department of Dermatology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Aimee S Payne
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Allan Seppänen
- Department of Psychiatry, Helsinki University Hospital, Helsinki, Finland
| | - Jane Setterfield
- Mucosal and Salivary Biology, Dental Institute, King's College London & St John's Institute of Dermatology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Hiroshi Shimizu
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Animesh A Sinha
- Department of Dermatology, Jacobs School of Medicine and Biomedical Sciences, University of Buffalo, Buffalo, New York, USA
| | - Eli Sprecher
- Department of Dermatology, Tel Aviv Medical Center, Tel Aviv, Israel
| | | | - Hideyuki Ujiie
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Detlef Zillikens
- Department of Dermatology, University of Lübeck, Lübeck, Germany
| | - Michael Hertl
- Department of Dermatology, Philipps University, Marburg, Germany
| | - Jens Waschke
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität, Munich, Germany
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40
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Furue M, Kadono T. Pemphigus, a pathomechanism of acantholysis. Australas J Dermatol 2017; 58:171-173. [PMID: 28211055 DOI: 10.1111/ajd.12562] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 08/13/2016] [Indexed: 12/16/2022]
Abstract
Autoantibodies to the desmosomal proteins desmoglein 1 and 3 cause pemphigus foliaceus and pemphigus vulgaris, which are characterised by keratinocyte dissociation (acantholysis) and intraepidermal blister formation. The passive transfer of pathogenic anti-desmoglein antibodies induces blisters in mice in vivo and the loss of keratinocyte adhesion in vitro. The pathogenetic mechanisms of acantholysis due to anti-desmoglein autoantibodies are not fully understood. However, recent studies have revealed that signalling-dependent and signalling-independent pathways are operative in the loss of cell adhesion. In this review, we focus on the pathomechanism of acantholysis due to autoantibodies to desmogleins and recent therapeutic approaches.
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Affiliation(s)
- Masutaka Furue
- Department of Dermatology, Kyushu University, Fukuoka, Japan
| | - Takafumi Kadono
- Department of Dermatology, St Marianna University School of Medicine, Kawasaki, Japan
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Meibomian gland cells display a differentiation-dependent composition of desmosomes. Histochem Cell Biol 2016; 146:685-694. [DOI: 10.1007/s00418-016-1475-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2016] [Indexed: 12/12/2022]
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A 3'UTR polymorphism marks differential KLRG1 mRNA levels through disruption of a miR-584-5p binding site and associates with pemphigus foliaceus susceptibility. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1859:1306-13. [PMID: 27424220 DOI: 10.1016/j.bbagrm.2016.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/29/2016] [Accepted: 07/12/2016] [Indexed: 11/23/2022]
Abstract
Genetic variations mapping to 3' untranslated regions (3'UTRs) may overlap with microRNA (miRNA) binding sites, therefore potentially interfering with translation inhibition or messenger RNA (mRNA) degradation. The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) located within the 3'UTRs of six candidate genes and predicted to interfere with miRNA ligation could account for disease-relevant differential mRNA levels. Focusing on pemphigus foliaceus (PF) - an autoimmune blistering skin condition with unique endemic patterns - we investigated whether nine 3'UTR SNPs from the CD1D, CTLA4, KLRD1, KLRG1, NKG7, and TNFSF13B genes differentially expressed in PF were disease-associated. The heterozygous genotype of the KLRG1 rs1805672 polymorphism was associated with increased predisposition to PF (A/G vs. A/A: P=0.038; OR=1.60), and a trend for augmented susceptibility was observed for carriers of the G allele (P=0.094; OR=1.44). In silico analyses suggested that rs1805672 G allele could disrupt binding of miR-584-5p, and indicated rs1805672 as an expression Quantitative Trait Locus (eQTL), with an effect on KLRG1 gene expression. Dual-luciferase assay showed that miR-584-5p mediated approximately 50% downregulation of the reporter gene's activity through the 3'UTR of KLRG1 harboring rs1805672 A allele (vs. miRNA-negative condition, P=0.006). This silencing relationship was lost after site-directed mutation to G allele (vs. miRNA-negative condition, P=0.391; vs. rs1805672 A allele, P=0.005). Collectively, these results suggest that a disease-associated SNP located within the 3'UTR of KLRG1 directly interferes with miR-584-5p binding, allowing for KLRG1 mRNA differential accumulation, which in turn may contribute to pathogenesis of autoimmune diseases, such as pemphigus.
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Desmoglein 3-Dependent Signaling Regulates Keratinocyte Migration and Wound Healing. J Invest Dermatol 2016; 136:301-10. [DOI: 10.1038/jid.2015.380] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 09/01/2015] [Accepted: 09/11/2015] [Indexed: 12/21/2022]
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