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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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Beckert B, Panico F, Pollmann R, Eming R, Banning A, Tikkanen R. Immortalized Human hTert/KER-CT Keratinocytes a Model System for Research on Desmosomal Adhesion and Pathogenesis of Pemphigus Vulgaris. Int J Mol Sci 2019; 20:ijms20133113. [PMID: 31247885 PMCID: PMC6651391 DOI: 10.3390/ijms20133113] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 06/24/2019] [Accepted: 06/24/2019] [Indexed: 12/18/2022] Open
Abstract
Pemphigus Vulgaris is an autoimmune disease that results in blister formation in the epidermis and in mucosal tissues due to antibodies recognizing desmosomal cadherins, mainly desmoglein-3 and -1. Studies on the molecular mechanisms of Pemphigus have mainly been carried out using the spontaneously immortalized human keratinocyte cell line HaCaT or in primary keratinocytes. However, both cell systems have suboptimal features, with HaCaT cells exhibiting a large number of chromosomal aberrations and mutated p53 tumor suppressor, whereas primary keratinocytes are short-lived, heterogeneous and not susceptible to genetic modifications due to their restricted life-span. We have here tested the suitability of the commercially available human keratinocyte cell line hTert/KER-CT as a model system for research on epidermal cell adhesion and Pemphigus pathomechanisms. We here show that hTert cells exhibit a calcium dependent expression of desmosomal cadherins and are well suitable for typical assays used for studies on Pemphigus, such as sequential detergent extraction and Dispase-based dissociation assay. Treatment with Pemphigus auto-antibodies results in loss of monolayer integrity and altered localization of desmoglein-3, as well as loss of colocalization with flotillin-2. Our findings demonstrate that hTert cells are well suitable for studies on epidermal cell adhesion and Pemphigus pathomechanisms.
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Affiliation(s)
- Benedikt Beckert
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, 35392 Giessen, Germany
| | - Francesca Panico
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, 35392 Giessen, Germany
| | - Robert Pollmann
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Baldingerstraße, 35043 Marburg, Germany
| | - Rüdiger Eming
- Department of Dermatology and Allergology, Philipps-Universität Marburg, Baldingerstraße, 35043 Marburg, Germany
| | - Antje Banning
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, 35392 Giessen, Germany
| | - Ritva Tikkanen
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, 35392 Giessen, Germany.
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3
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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: 18] [Impact Index Per Article: 3.0] [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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4
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Ishii K. Importance of serological tests in diagnosis of autoimmune blistering diseases. J Dermatol 2016; 42:3-10. [PMID: 25558946 DOI: 10.1111/1346-8138.12703] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 10/08/2014] [Indexed: 01/07/2023]
Abstract
Autoimmune blistering diseases are organ-specific autoimmune diseases characterized by autoantibodies against structural proteins that maintain cell-cell (pemphigus diseases) and cell-matrix adhesions (pemphigoid diseases) in the skin and mucous membranes. Over the last few decades, identification of autoantigens and extensive characterization of autoantibodies have improved understanding of the pathogenesis of these diseases. In addition, the development of new sensitive and specific immunoassays enabled accurate diagnosis and proper evaluation of disease activity in autoimmune blistering diseases. In this review, we describe practical updates for molecular diagnostic tests for autoimmune blistering diseases and the basis for interpreting the results of the assays.
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Affiliation(s)
- Ken Ishii
- Department of Dermatology, Toho University Omori Medical Center, Tokyo, Japan
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Nishikawa R, Takahashi H, Matsuda M, Imaoka K, Ogawa M, Teye K, Tsuchisaka A, Koga H, Komorowski L, Probst C, Hachiya T, Fritzler MJ, Ishii N, Ohata C, Furumura M, Krol RP, Muro Y, Morita E, Hashimoto T. Anti-early endosome antigen 1 autoantibodies were detected in a pemphigus-like patient but not in the majority of pemphigus diseases. Exp Dermatol 2016; 25:368-74. [PMID: 26909655 DOI: 10.1111/exd.12981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/07/2016] [Indexed: 11/29/2022]
Abstract
Although the major autoantigens in classic pemphigus are desmogleins, sera from various types of pemphigus react with a number of other molecules, including desmocollins and plakin proteins. However, other novel pemphigus-related autoantigens remain to be identified. In this study, immunoblotting for serum from an atypical autoimmune bullous disease patient identified an unknown 175 kDa protein. Subsequent studies using two-dimensional gel electrophoresis, immunoblotting and mass-spectrometry identified the 175 kDa protein as early endosome antigen 1 (EEA1). This finding was confirmed by subsequent immunological studies, including indirect immunofluorescence of skin and cultured keratinocytes, two-dimensional gel electrophoresis and immunoblotting with anti-EEA1 polyclonal antibody, and preabsorption with EEA1 recombinant protein. Finally, we developed a novel BIOCHIP assay using full-length EEA1 recombinant protein to detect anti-EEA1 antibodies. However, none of 35 sera from various types of pemphigus showed anti-EEA1 antibodies in the BIOCHIP assay, with the exception of the serum from the index case. In addition, various findings in the index case did not suggest pathogenic role of anti-EEA1 autoantibodies. Therefore, although we successfully identified the 175 kDa protein reacted by a serum of an atypical pemphigus-like patient as EEA1, novel BIOCHIP study for other pemphigus sera indicated that EEA1 is not a common and pathogenic autoantigen in pemphigus.
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Affiliation(s)
- Ryuhei Nishikawa
- Department of Dermatology, Kurume University School of Medicine, and Kurume University Institute of Cutaneous Cell Biology, Kurume, Fukuoka, Japan
| | - Hitoshi Takahashi
- Department of Dermatology, Shimane University Faculty of Medicine, Izumo, Shimane, Japan
| | - Mitsuhiro Matsuda
- Department of Dermatology, Kurume University School of Medicine, and Kurume University Institute of Cutaneous Cell Biology, Kurume, Fukuoka, Japan
| | - Kaoru Imaoka
- Department of Dermatology, Shimane University Faculty of Medicine, Izumo, Shimane, Japan
| | - Masahiro Ogawa
- Department of Dermatology, Kurume University School of Medicine, and Kurume University Institute of Cutaneous Cell Biology, Kurume, Fukuoka, Japan
| | - Kwesi Teye
- Department of Dermatology, Kurume University School of Medicine, and Kurume University Institute of Cutaneous Cell Biology, Kurume, Fukuoka, Japan
| | - Atsunari Tsuchisaka
- Department of Dermatology, Kurume University School of Medicine, and Kurume University Institute of Cutaneous Cell Biology, Kurume, Fukuoka, Japan
| | - Hiroshi Koga
- Department of Dermatology, Kurume University School of Medicine, and Kurume University Institute of Cutaneous Cell Biology, Kurume, Fukuoka, Japan
| | - Lars Komorowski
- Institute for Experimental Immunology, Affiliated to Euroimmun AG, Luebeck, Germany
| | - Christian Probst
- Institute for Experimental Immunology, Affiliated to Euroimmun AG, Luebeck, Germany
| | - Takahisa Hachiya
- Antibody Engineering Department/Manufacturing Division, Medical & Biological Laboratories Co., Ltd., Nagoya, Japan
| | | | - Norito Ishii
- Department of Dermatology, Kurume University School of Medicine, and Kurume University Institute of Cutaneous Cell Biology, Kurume, Fukuoka, Japan
| | - Chika Ohata
- Department of Dermatology, Kurume University School of Medicine, and Kurume University Institute of Cutaneous Cell Biology, Kurume, Fukuoka, Japan
| | - Minao Furumura
- Department of Dermatology, Kurume University School of Medicine, and Kurume University Institute of Cutaneous Cell Biology, Kurume, Fukuoka, Japan
| | - Rafal P Krol
- Department of Dermatology, Kurume University School of Medicine, and Kurume University Institute of Cutaneous Cell Biology, Kurume, Fukuoka, Japan
| | - Yoshinao Muro
- Division of Connective Tissue Disease and Autoimmunity, Department of Dermatology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Eishin Morita
- Department of Dermatology, Shimane University Faculty of Medicine, Izumo, Shimane, Japan
| | - Takashi Hashimoto
- Department of Dermatology, Kurume University School of Medicine, and Kurume University Institute of Cutaneous Cell Biology, Kurume, Fukuoka, Japan
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Cho MJ, Lo ASY, Mao X, Nagler AR, Ellebrecht CT, Mukherjee EM, Hammers CM, Choi EJ, Sharma PM, Uduman M, Li H, Rux AH, Farber SA, Rubin CB, Kleinstein SH, Sachais BS, Posner MR, Cavacini LA, Payne AS. Shared VH1-46 gene usage by pemphigus vulgaris autoantibodies indicates common humoral immune responses among patients. Nat Commun 2014; 5:4167. [PMID: 24942562 PMCID: PMC4120239 DOI: 10.1038/ncomms5167] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 05/20/2014] [Indexed: 12/13/2022] Open
Abstract
Pemphigus vulgaris (PV) is a potentially fatal blistering disease caused by autoantibodies (autoAbs) against desmoglein 3 (Dsg3). Here, we clone anti-Dsg3 antibodies (Abs) from four PV patients and identify pathogenic VH1-46 autoAbs from all four patients. Unexpectedly, VH1-46 autoAbs had relatively few replacement mutations. We reverted antibody somatic mutations to their germline sequences to determine the requirement of mutations for autoreactivity. Three of five VH1-46 germline-reverted Abs maintain Dsg3 binding, compared with zero of five non-VH1-46 germline-reverted Abs. Site-directed mutagenesis of VH1-46 Abs demonstrates that acidic amino-acid residues introduced by somatic mutation or heavy chain VDJ recombination are necessary and sufficient for Dsg3 binding. Our data suggest that VH1-46 autoantibody gene usage is commonly found in PV because VH1-46 Abs require few to no mutations to acquire Dsg3 autoreactivity, which may favour their early selection. Common VH gene usage indicates common humoral immune responses, even among unrelated patients.
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Affiliation(s)
- Michael Jeffrey Cho
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Agnes S Y Lo
- Division of Hematology-Oncology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA
| | - Xuming Mao
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Arielle R Nagler
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Christoph T Ellebrecht
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Eric M Mukherjee
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Christoph M Hammers
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Eun-Jung Choi
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Preety M Sharma
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Mohamed Uduman
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, and Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06511, USA
| | - Hong Li
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Ann H Rux
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Sara A Farber
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Courtney B Rubin
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Steven H Kleinstein
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, and Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06511, USA
| | - Bruce S Sachais
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Marshall R Posner
- The Tisch Cancer Institute, Mount Sinai Medical Center, New York, New York 10029, USA
| | - Lisa A Cavacini
- The Tisch Cancer Institute, Mount Sinai Medical Center, New York, New York 10029, USA
| | - Aimee S Payne
- Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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7
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Stahley SN, Saito M, Faundez V, Koval M, Mattheyses AL, Kowalczyk AP. Desmosome assembly and disassembly are membrane raft-dependent. PLoS One 2014; 9:e87809. [PMID: 24498201 PMCID: PMC3907498 DOI: 10.1371/journal.pone.0087809] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Accepted: 01/01/2014] [Indexed: 11/20/2022] Open
Abstract
Strong intercellular adhesion is critical for tissues that experience mechanical stress, such as the skin and heart. Desmosomes provide adhesive strength to tissues by anchoring desmosomal cadherins of neighboring cells to the intermediate filament cytoskeleton. Alterations in assembly and disassembly compromise desmosome function and may contribute to human diseases, such as the autoimmune skin blistering disease pemphigus vulgaris (PV). We previously demonstrated that PV auto-antibodies directed against the desmosomal cadherin desmoglein 3 (Dsg3) cause loss of adhesion by triggering membrane raft-mediated Dsg3 endocytosis. We hypothesized that raft membrane microdomains play a broader role in desmosome homeostasis by regulating the dynamics of desmosome assembly and disassembly. In human keratinocytes, Dsg3 is raft associated as determined by biochemical and super resolution immunofluorescence microscopy methods. Cholesterol depletion, which disrupts rafts, prevented desmosome assembly and adhesion, thus functionally linking rafts to desmosome formation. Interestingly, Dsg3 did not associate with rafts in cells lacking desmosomal proteins. Additionally, PV IgG-induced desmosome disassembly occurred by redistribution of Dsg3 into raft-containing endocytic membrane domains, resulting in cholesterol-dependent loss of adhesion. These findings demonstrate that membrane rafts are required for desmosome assembly and disassembly dynamics, suggesting therapeutic potential for raft targeting agents in desmosomal diseases such as PV.
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Affiliation(s)
- Sara N. Stahley
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Masataka Saito
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Victor Faundez
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Michael Koval
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Division of Pulmonary, Allergy and Critical Care Medicine, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Alexa L. Mattheyses
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Andrew P. Kowalczyk
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Department of Dermatology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia, United States of America
- * E-mail:
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