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Simpson CL, Tiwaa A, Zaver SA, Johnson CJ, Chu EY, Harms PW, Gudjonsson JE. ERK hyperactivation in epidermal keratinocytes impairs intercellular adhesion and drives Grover disease pathology. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.30.591953. [PMID: 38746263 PMCID: PMC11092613 DOI: 10.1101/2024.04.30.591953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Grover disease is an acquired dermatologic disorder characterized by pruritic vesicular and eroded skin lesions. While its pathologic features are well-defined, including impaired cohesion of epidermal keratinocytes, the etiology of Grover disease remains unclear and it lacks any FDA-approved therapy. Interestingly, drug-induced Grover disease occurs in patients treated with B-RAF inhibitors that can paradoxically activate C-RAF and the downstream kinase MEK. We recently identified hyperactivation of MEK and ERK as key drivers of Darier disease, which is histologically identical to Grover disease, supporting our hypothesis that they share a pathogenic mechanism. To model drug-induced Grover disease, we treated human keratinocytes with clinically utilized B-RAF inhibitors dabrafenib or vemurafenib and leveraged a fluorescent biosensor to confirm they activated ERK, which disrupted intercellular junctions and compromised keratinocyte sheet integrity. Consistent with clinical data showing concomitant MEK blockade prevents Grover disease in patients receiving B-RAF inhibitors, we found that MEK inhibition suppressed excess ERK activity to rescue cohesion of B-RAF-inhibited keratinocytes. Validating these results, we demonstrated ERK hyperactivation in skin biopsies of vemurafenib-induced Grover disease, but also in spontaneous Grover disease. In sum, our data define a pathogenic role for ERK hyperactivation in Grover disease and support MEK inhibition as a therapeutic strategy. GRAPHICAL ABSTRACT
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Starr H, Howerth EW, Leon R, Gogal RM, Banovic F. Microarray Gene Expression Analysis of Lesional Skin in Canine Pemphigus Foliaceus. Vet Sci 2024; 11:89. [PMID: 38393106 PMCID: PMC10893259 DOI: 10.3390/vetsci11020089] [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: 12/11/2023] [Revised: 02/02/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
Canine pemphigus foliaceus (PF) is considered the most common autoimmune skin disease in dogs; the mechanism of PF disease development is currently poorly understood. Therefore, this study aimed to characterize the molecular mechanisms and altered biological pathways in the skin lesions of canine PF patients. Using an RNA microarray on formalin-fixed, paraffin-embedded samples, we analyzed the transcriptome of canine PF lesional skin (n = 7) compared to healthy skin (n = 5). Of the 800 genes analyzed, 420 differentially expressed genes (DEGs) (p < 0.05) were found. Of those, 338 genes were significantly upregulated, including pro-inflammatory and Th17-related genes. Cell type profiling found enhancement of several cell types, such as neutrophils, T-cells, and macrophages, in PF skin compared to healthy skin. Enrichment analyses of the upregulated DEGs resulted in 78 statistically significant process networks (FDR < 0.05), including the Janus kinase signal transducer and activator of transcription (JAK-STAT) and mitogen-activated protein kinase (MAPK) signaling. In conclusion, canine PF lesional immune signature resembles previously published changes in human pemphigus skin lesions. Further studies with canine PF lesional skin using next-generation sequencing (e.g., RNA sequencing, spatial transcriptomics, etc.) and the development of canine keratinocyte/skin explant PF models are needed to elucidate the pathogenesis of this debilitating disease.
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Affiliation(s)
- Haley Starr
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (H.S.); (R.L.)
| | - Elizabeth W. Howerth
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA;
| | - Renato Leon
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (H.S.); (R.L.)
| | - Robert M. Gogal
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA;
| | - Frane Banovic
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (H.S.); (R.L.)
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Han K, Li SS, Pan W, Xu MN, Zhong MZ, Zhang WJ, Huang XW, Zeng K. ERK/MEK Pathway Regulates Th17 Cell Differentiation in Patients with Pemphigus Vulgaris. Indian J Dermatol 2023; 68:724. [PMID: 38371571 PMCID: PMC10868988 DOI: 10.4103/ijd.ijd_924_22] [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] [Indexed: 02/20/2024] Open
Abstract
Background T helper (Th) cells are involved in the pathogenesis of pemphigus vulgaris (PV). However, the mechanism still needs more exploration. Aims This study aimed to evaluate the molecular mechanism of the dysregulation of Th17 cells in the peripheral blood of patients with PV. Materials and Methods Serum levels of IL-17 and anti-Dsg3 titres in patients with PV were analysed using ELISA. The mRNA expression of retinoic acid orphan receptor γt (RORγt) in CD4+ T cells was detected using reverse transcription-quantitative PCR (qPCR). The number of Th17 cells was examined using flow cytometry. Western blot analysis and immunofluorescent staining were also performed to investigate the expression levels of ERK/MAPK signalling proteins and Th17 lineage-associated proteins. Results The proportion of Th17 cells and Th17 spectrum-associated proteins (p-STAT3, RORγt and IL-17) were upregulated in CD4+ cells in PV patients. The increased transcriptional levels of RORγt and IL-17 correlated positively with the severity of PV. Elevated phosphorylation of the ERK signalling factors was found in the collected CD4+ T cells in PV patients. The inhibition of the ERK signalling pathway significantly reduced the differentiation of Th17 cells in PV patients in vitro. Conclusion Th17 cells are essential in the dysregulation of PV, and ERK signalling is involved in Th17-type immunity and promotes the development of PV. The study here provides us with a potential therapeutic target for PV.
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Affiliation(s)
- Kai Han
- From the Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Song-Shan Li
- From the Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Wen Pan
- Division of Infectious Diseases, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Mei-Nian Xu
- From the Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Mei-Zhen Zhong
- From the Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Wen-Jing Zhang
- From the Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Xiao-Wen Huang
- From the Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Kang Zeng
- From the Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
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Nagler S, Ghoreishi Y, Kollmann C, Kelm M, Gerull B, Waschke J, Burkard N, Schlegel N. Plakophilin 2 regulates intestinal barrier function by modulating protein kinase C activity in vitro. Tissue Barriers 2023; 11:2138061. [PMID: 36280901 PMCID: PMC10606776 DOI: 10.1080/21688370.2022.2138061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/29/2022] [Accepted: 10/16/2022] [Indexed: 10/31/2022] Open
Abstract
Previous data provided evidence for a critical role of desmosomes to stabilize intestinal epithelial barrier (IEB) function. These studies suggest that desmosomes not only contribute to intercellular adhesion but also play a role as signaling hubs. The contribution of desmosomal plaque proteins plakophilins (PKP) in the intestinal epithelium remains unexplored. The intestinal expression of PKP2 and PKP3 was verified in human gut specimens, human intestinal organoids as well as in Caco2 cells whereas PKP1 was not detected. Knock-down of PKP2 using siRNA in Caco2 cells resulted in loss of intercellular adhesion and attenuated epithelial barrier. This was paralleled by changes of the whole desmosomal complex, including loss of desmoglein2, desmocollin2, plakoglobin and desmoplakin. In addition, tight junction proteins claudin1 and claudin4 were reduced following the loss of PKP2. Interestingly, siRNA-induced loss of PKP3 did not change intercellular adhesion and barrier function in Caco2 cells, while siRNA-induced loss of both PKP2 and PKP3 augmented the changes observed for reduced PKP2 alone. Moreover, loss of PKP2 and PKP2/3, but not PKP3, resulted in reduced activity levels of protein kinase C (PKC). Restoration of PKC activity using Phorbol 12-myristate 13-acetate (PMA) rescued loss of intestinal barrier function and attenuated the reduced expression patterns of claudin1 and claudin4. Immunostaining, proximity ligation assays and co-immunoprecipitation revealed a direct interaction between PKP2 and PKC. In summary, our in vitro data suggest that PKP2 plays a critical role for intestinal barrier function by providing a signaling hub for PKC-mediated expression of tight junction proteins claudin1 and claudin4.
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Affiliation(s)
- Simon Nagler
- Department of General, Visceral, Transplant, Vascular and Paediatric Surgery University Hospital Würzburg, Wuerzburg97080, Germany
| | - Yalda Ghoreishi
- Department of General, Visceral, Transplant, Vascular and Paediatric Surgery University Hospital Würzburg, Wuerzburg97080, Germany
| | - Catherine Kollmann
- Department of General, Visceral, Transplant, Vascular and Paediatric Surgery University Hospital Würzburg, Wuerzburg97080, Germany
| | - Matthias Kelm
- Department of General, Visceral, Transplant, Vascular and Paediatric Surgery University Hospital Würzburg, Wuerzburg97080, Germany
| | - Brenda Gerull
- Comprehensive Heart Failure Center and Department of Medicine I, University Hospital Würzburg, Würzburg, Germany
| | - Jens Waschke
- Department I, Ludwig-Maximilians-Universität München, Institute of Anatomy and Cell Biology, Munich, Germany
| | - Natalie Burkard
- Department of General, Visceral, Transplant, Vascular and Paediatric Surgery University Hospital Würzburg, Wuerzburg97080, Germany
| | - Nicolas Schlegel
- Department of General, Visceral, Transplant, Vascular and Paediatric Surgery University Hospital Würzburg, Wuerzburg97080, Germany
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Zaver SA, Sarkar MK, Egolf S, Zou J, Tiwaa A, Capell BC, Gudjonsson JE, Simpson CL. Targeting SERCA2 in organotypic epidermis reveals MEK inhibition as a therapeutic strategy for Darier disease. JCI Insight 2023; 8:e170739. [PMID: 37561594 PMCID: PMC10561730 DOI: 10.1172/jci.insight.170739] [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: 03/21/2023] [Accepted: 08/08/2023] [Indexed: 08/12/2023] Open
Abstract
Mutation of the ATP2A2 gene encoding sarco-endoplasmic reticulum calcium ATPase 2 (SERCA2) was linked to Darier disease more than 2 decades ago; however, there remain no targeted therapies for this disorder causing recurrent skin blistering and infections. Since Atp2a2-knockout mice do not phenocopy its pathology, we established a human tissue model of Darier disease to elucidate its pathogenesis and identify potential therapies. Leveraging CRISPR/Cas9, we generated human keratinocytes lacking SERCA2, which replicated features of Darier disease, including weakened intercellular adhesion and defective differentiation in organotypic epidermis. To identify pathogenic drivers downstream of SERCA2 depletion, we performed RNA sequencing and proteomics analysis. SERCA2-deficient keratinocytes lacked desmosomal and cytoskeletal proteins required for epidermal integrity and exhibited excess MAPK signaling, which modulates keratinocyte adhesion and differentiation. Immunostaining patient biopsies substantiated these findings, with lesions showing keratin deficiency, cadherin mislocalization, and ERK hyperphosphorylation. Dampening ERK activity with MEK inhibitors rescued adhesive protein expression and restored keratinocyte sheet integrity despite SERCA2 depletion or chemical inhibition. In sum, coupling multiomic analysis with human organotypic epidermis as a preclinical model, we found that SERCA2 haploinsufficiency disrupts critical adhesive components in keratinocytes via ERK signaling and identified MEK inhibition as a treatment strategy for Darier disease.
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Affiliation(s)
- Shivam A. Zaver
- Division of Dermatology, Department of Medicine, and
- Medical Scientist Training Program, University of Washington, Seattle, Washington, USA
| | - Mrinal K. Sarkar
- Department of Dermatology, University of Michigan, Ann Arbor, Michigan, USA
| | - Shaun Egolf
- Department of Dermatology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Jonathan Zou
- Department of Dermatology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Afua Tiwaa
- Division of Dermatology, Department of Medicine, and
| | - Brian C. Capell
- Department of Dermatology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | | | - Cory L. Simpson
- Division of Dermatology, Department of Medicine, and
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA
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Zaver SA, Sarkar MK, Egolf S, Zou J, Tiwaa A, Capell BC, Gudjonsson JE, Simpson CL. Targeting SERCA2 in organotypic epidermis reveals MEK inhibition as a therapeutic strategy for Darier disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.07.531620. [PMID: 36945477 PMCID: PMC10028894 DOI: 10.1101/2023.03.07.531620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Mutation of the ATP2A2 gene encoding sarco-endoplasmic reticulum calcium ATPase 2 (SERCA2) was linked to Darier disease more than two decades ago; however, there remain no targeted therapies for this disorder causing recurrent skin blistering and infections. Since Atp2a2 knockout mice do not phenocopy its pathology, we established a human tissue model of Darier disease to elucidate its pathogenesis and identify potential therapies. Leveraging CRISPR/Cas9, we generated human keratinocytes lacking SERCA2, which replicated features of Darier disease, including weakened intercellular adhesion and defective differentiation in organotypic epidermis. To identify pathogenic drivers downstream of SERCA2 depletion, we performed RNA sequencing and proteomic analysis. SERCA2-deficient keratinocytes lacked desmosomal and cytoskeletal proteins required for epidermal integrity and exhibited excess MAP kinase signaling, which modulates keratinocyte adhesion and differentiation. Immunostaining patient biopsies substantiated these findings with lesions showing keratin deficiency, cadherin mis-localization, and ERK hyper-phosphorylation. Dampening ERK activity with MEK inhibitors rescued adhesive protein expression and restored keratinocyte sheet integrity despite SERCA2 depletion or chemical inhibition. In sum, coupling multi-omic analysis with human organotypic epidermis as a pre-clinical model, we found that SERCA2 haploinsufficiency disrupts critical adhesive components in keratinocytes via ERK signaling and identified MEK inhibition as a treatment strategy for Darier disease.
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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, Pircher J, Steinert L, Meier K, Ghoreschi K, Vielmuth F, Kugelmann D, Waschke J. Dsg1 and Dsg3 Composition of Desmosomes Across Human Epidermis and Alterations in Pemphigus Vulgaris Patient Skin. Front Immunol 2022; 13:884241. [PMID: 35711465 PMCID: PMC9196036 DOI: 10.3389/fimmu.2022.884241] [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: 02/25/2022] [Accepted: 04/12/2022] [Indexed: 11/13/2022] Open
Abstract
Desmosomes are important epidermal adhesion units and signalling hubs, which play an important role in pemphigus pathogenesis. Different expression patterns of the pemphigus autoantigens desmoglein (Dsg)1 and Dsg3 across different epidermal layers have been demonstrated. However, little is known about changes in desmosome composition in different epidermal layers or in patient skin. The aim of this study was thus to characterize desmosome composition in healthy and pemphigus skin using super-resolution microscopy. An increasing Dsg1/Dsg3 ratio from lower basal (BL) to uppermost granular layer (GL) was observed. Within BL desmosomes, Dsg1 and Dsg3 were more homogeneously distributed whereas superficial desmosomes mostly comprised one of the two molecules or domains containing either one but not both. Extradesmosomal, desmoplakin (Dp)-independent, co-localization of Dsg3 with plakoglobin (Pg) was found mostly in BL and extradesmosomal Dsg1 co-localization with Pg in all layers. In contrast, in the spinous layer (SL) most Dsg1 and Dsg3 staining was confined to desmosomes, as revealed by the co-localization with Dp. In pemphigus patient skin, Dsg1 and Dsg3 immunostaining was altered especially along blister edges. The number of desmosomes in patient skin was reduced significantly in basal and spinous layer keratinocytes with only few split desmosomes found. In addition, Dsg1-Pg co-localization at the apical BL and Dsg3-Pg co-localization in SL were significantly reduced in patients, suggesting that that extradesmosomal Dsg molecules were affected. These results support the hypothesis that pemphigus is a desmosome assembly disease and may help to explain histopathologic differences between pemphigus phenotypes.
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Affiliation(s)
- Thomas Schmitt
- Chair of Vegetative Anatomy, Instiute of Anatomy, Faculty of Medicine, Ludwig-Maximilian-Universität München (LMU) Munich, München, Germany
| | - Julia Pircher
- Chair of Vegetative Anatomy, Instiute of Anatomy, Faculty of Medicine, Ludwig-Maximilian-Universität München (LMU) Munich, München, Germany
| | - Letyfee Steinert
- Chair of Vegetative Anatomy, Instiute of Anatomy, Faculty of Medicine, Ludwig-Maximilian-Universität München (LMU) Munich, München, Germany
| | - Katharina Meier
- Department of Dermatology, Venereology and Allergology, Charité-Universitätsmedizin Berli, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Kamran Ghoreschi
- Department of Dermatology, Venereology and Allergology, Charité-Universitätsmedizin Berli, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Franziska Vielmuth
- Chair of Vegetative Anatomy, Instiute of Anatomy, Faculty of Medicine, Ludwig-Maximilian-Universität München (LMU) Munich, München, Germany
| | - Daniela Kugelmann
- Chair of Vegetative Anatomy, Instiute of Anatomy, Faculty of Medicine, Ludwig-Maximilian-Universität München (LMU) Munich, München, Germany
| | - Jens Waschke
- Chair of Vegetative Anatomy, Instiute of Anatomy, Faculty of Medicine, Ludwig-Maximilian-Universität München (LMU) Munich, München, Germany
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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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11
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Yeruva S, Waschke J. Structure and regulation of desmosomes in intercalated discs: Lessons from epithelia. J Anat 2022; 242:81-90. [PMID: 35128661 PMCID: PMC9773171 DOI: 10.1111/joa.13634] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/22/2021] [Accepted: 01/10/2022] [Indexed: 12/25/2022] Open
Abstract
For electromechanical coupling of cardiomyocytes, intercalated discs (ICDs) are pivotal as highly specialized intercellular contact areas. ICD consists of adhesive contacts, such as desmosomes and adherens junctions (AJs) that are partially intermingled and thereby form an area composita to provide mechanical strength, as well as gap junctions (GJ) and sodium channels for excitation propagation. In contrast, in epithelia, mixed junctions with features of desmosomes and AJs are regarded as transitory primarily during the formation of desmosomes. The anatomy of desmosomes is defined by a typical ultrastructure with dense intracellular plaques anchoring the cadherin-type adhesion molecules to the intermediate filament cytoskeleton. Desmosomal diseases characterized by impaired adhesive and signalling functions of desmosomal contacts lead to arrhythmogenic cardiomyopathy when affecting cardiomyocytes and cause pemphigus when manifesting in keratinocytes or present as cardiocutaneous syndromes when both cell types are targeted by the disease, which underscores the high biomedical relevance of these cell contacts. Therefore, comparative analyses regarding the structure and regulation of desmosomal contacts in cardiomyocytes and epithelial cells are helpful to better understand disease pathogenesis. In this brief review, we describe the structural properties of ICD compared to epithelial desmosomes and suggest that mechanisms regulating adhesion may at least in part be comparable. Also, we discuss whether phenomena such as hyperadhesion or the bidirectional regulation of desmosomes to serve as signalling hubs in epithelial cells may also be relevant for ICD.
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Affiliation(s)
- Sunil Yeruva
- Ludwig‐Maximilian‐Universität München, Anatomische Anstalt, Lehrstuhl Anatomie I – Vegetative AnatomieMunichGermany
| | - Jens Waschke
- Ludwig‐Maximilian‐Universität München, Anatomische Anstalt, Lehrstuhl Anatomie I – Vegetative AnatomieMunichGermany
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12
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Egu DT, Schmitt T, Sigmund AM, Waschke J. Electron microscopy reveals that phospholipase C and Ca2+ signaling regulate keratin filament uncoupling from desmosomes in Pemphigus. Ann Anat 2022; 241:151904. [DOI: 10.1016/j.aanat.2022.151904] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 01/18/2022] [Accepted: 01/20/2022] [Indexed: 12/27/2022]
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Zhong C, Zhao H, Xie X, Qi Z, Li Y, Jia L, Zhang J, Lu Y. Protein Kinase C-Mediated Hyperphosphorylation and Lateralization of Connexin 43 Are Involved in Autoimmune Myocarditis-Induced Prolongation of QRS Complex. Front Physiol 2022; 13:815301. [PMID: 35418879 PMCID: PMC9000987 DOI: 10.3389/fphys.2022.815301] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/25/2022] [Indexed: 02/05/2023] Open
Abstract
Myocarditis is a serious and potentially life-threatening disease, which leads to cardiac dysfunction and sudden cardiac death. An increasing number of evidence suggests that myocarditis is also a malignant complication of coronavirus pneumonia, associated with heart failure and sudden cardiac death. Prolonged QRS complexes that are related to malignant arrhythmias caused by myocarditis significantly increase the risk of sudden cardiac death in patients. However, the molecular mechanisms are not fully known at present. In this study, we identify protein kinase C (PKC) as a new regulator of the QRS complex. In isolated hearts of normal rats, the PKC agonist, phorbol-12-myristate-13-acetate (PMA), induced prolongation of the QRS complex. Mechanistically, hyperphosphorylation and lateralization of connexin 43 (Cx43) by PKC induced depolymerization and internalization of Cx43 gap junction channels and prolongation of the QRS duration. Conversely, administration of the PKC inhibitor, Ro-32-0432, in experimental autoimmune myocarditis (EAM) rats after the most severe inflammation period still significantly rescued the stability of the Cx43 gap junction and alleviated prolongation of the QRS complex. Ro-32-0432 reduced phosphorylation and blocked translocation of Cx43 in EAM rat heart but did not regulate the mRNA expression level of ventricular ion channels and the other regulatory proteins, which indicates that the inhibition of PKC might have no protective effect on ion channels that generate ventricular action potential in EAM rats. These results suggest that the pharmacological inhibition of PKC ameliorates the prolongation of the QRS complex via suppression of Cx43 hyperphosphorylation, lateralization, and depolymerization of Cx43 gap junction channels in EAM rats, which provides a potential therapeutic strategy for myocarditis-induced arrhythmias.
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Affiliation(s)
- Chunlian Zhong
- School of Material and Chemical Engineering, Minjiang University, Fuzhou, China
- Fuzhou Institute of Oceanography, Fuzhou, China
| | - Huan Zhao
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Life Sciences, National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, China
| | - Xinwen Xie
- Liancheng County General Hospital, Longyan, China
| | - Zhi Qi
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| | - Yumei Li
- School of Basic Medicine, Gannan Medical University, Ganzhou, China
| | - Lee Jia
- School of Material and Chemical Engineering, Minjiang University, Fuzhou, China
- Fuzhou Institute of Oceanography, Fuzhou, China
- *Correspondence: Lee Jia, ,
| | - Jinwei Zhang
- Xiamen Key Laboratory of Cardiovascular Disease, Xiamen Cardiovascular Hospital Xiamen University, Xiamen, China
- Hatherly Laboratories, Medical School, College of Medicine and Health, Institute of Biomedical and Clinical Sciences, University of Exeter, Exeter, United Kingdom
- Jinwei Zhang,
| | - Yusheng Lu
- School of Material and Chemical Engineering, Minjiang University, Fuzhou, China
- Fuzhou Institute of Oceanography, Fuzhou, China
- Yusheng Lu, ,
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14
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Zhuang P, Xie L, Zhang Y, Yuan Y, Liu H, Bi C, Zhao H, Li Y, Zhang Y. Inhibition of desmoglein-1 by aspirin leads to synthetic lethality of keratinocytes in Shuanghuanglian-induced cutaneous eruption response. Toxicol Lett 2021; 349:145-154. [PMID: 34126182 DOI: 10.1016/j.toxlet.2021.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 06/06/2021] [Accepted: 06/09/2021] [Indexed: 11/30/2022]
Abstract
Cutaneous eruptions caused by the combination of Chinese and Western medicine have attracted widespread attention; however, the underlying mechanism remains unclear. This study aimed to evaluate the potential mechanism of cutaneous eruptions in vivo and in vitro using the combination of Shuanghuanglian injection powder (SHL) and aspirin (ASA) as an example. ASA and SHL co-administration induced inflammatory responses in HaCat cells, as evidenced by marked increases in the expression of IL-4 and TNF-α, and the level of apoptosis. Additionally, histopathological investigation of mice skin tissues showed local inflammatory cell infiltration. Western boltting was used to detect the effects of ASA on desmoglein-1 (DSG1) expression; we found that DSG1 expression was down-regulated in vivo and in vitro. Finally, the key components of SHL were administered to HaCat cells with down-regulated DSG1; it was seen that neochlorogenic acid and rutin have a significant effect on HaCat cell apoptosis. These results demonstrate that DSG1 deficiency is a potential cause of cutaneous eruptions caused by the combination of SHL and ASA, and neochlorogenic acid and rutin are the main allergenic components. This study provides a new research strategy for the safety evaluation of integrated traditional Chinese and Western medicine.
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Affiliation(s)
- Pengwei Zhuang
- Chinese Materia Medica College, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China; Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China
| | - Lijuan Xie
- Chinese Materia Medica College, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China
| | - Yidan Zhang
- Chinese Materia Medica College, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China
| | - Yu Yuan
- Chinese Materia Medica College, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China
| | - Hui Liu
- Chinese Materia Medica College, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China
| | - Chenghao Bi
- Chinese Materia Medica College, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China
| | - Huan Zhao
- Chinese Materia Medica College, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China
| | - Yubo Li
- Chinese Materia Medica College, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China.
| | - Yanjun Zhang
- Chinese Materia Medica College, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China; Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China.
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15
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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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16
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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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17
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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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18
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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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19
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Shoykhet M, Trenz S, Kempf E, Williams T, Gerull B, Schinner C, Yeruva S, Waschke J. Cardiomyocyte adhesion and hyperadhesion differentially require ERK1/2 and plakoglobin. JCI Insight 2020; 5:140066. [PMID: 32841221 PMCID: PMC7526536 DOI: 10.1172/jci.insight.140066] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/12/2020] [Indexed: 12/23/2022] Open
Abstract
Arrhythmogenic cardiomyopathy (AC) is a heart disease often caused by mutations in genes coding for desmosomal proteins, including desmoglein-2 (DSG2), plakoglobin (PG), and desmoplakin (DP). Therapy is based on symptoms and limiting arrhythmia, because the mechanisms by which desmosomal components control cardiomyocyte function are largely unknown. A new paradigm could be to stabilize desmosomal cardiomyocyte adhesion and hyperadhesion, which renders desmosomal adhesion independent from Ca2+. Here, we further characterized the mechanisms behind enhanced cardiomyocyte adhesion and hyperadhesion. Dissociation assays performed in HL-1 cells and murine ventricular cardiac slice cultures allowed us to define a set of signaling pathways regulating cardiomyocyte adhesion under basal and hyperadhesive conditions. Adrenergic signaling, activation of PKC, and inhibition of p38MAPK enhanced cardiomyocyte adhesion, referred to as positive adhesiotropy, and induced hyperadhesion. Activation of ERK1/2 paralleled positive adhesiotropy, whereas adrenergic signaling induced PG phosphorylation at S665 under both basal and hyperadhesive conditions. Adrenergic signaling and p38MAPK inhibition recruited DSG2 to cell junctions. In PG-deficient mice with an AC phenotype, only PKC activation and p38MAPK inhibition enhanced cardiomyocyte adhesion. Our results demonstrate that cardiomyocyte adhesion can be stabilized by different signaling mechanisms, which are in part offset in PG-deficient AC. Desmosome mediated cardiomyocyte adhesion, crucial in the pathology of arrhythmogenic cardiomyopathy, is differentially regulated by multiple signaling mechanisms that depend either on ERK1/2 or plakoglobin.
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Affiliation(s)
- Maria Shoykhet
- Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Sebastian Trenz
- Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Ellen Kempf
- Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Tatjana Williams
- Comprehensive Heart Failure Center and Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany
| | - Brenda Gerull
- Comprehensive Heart Failure Center and Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany
| | - Camilla Schinner
- Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Sunil Yeruva
- Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Jens Waschke
- Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
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