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Rietscher K, Jahnke HG, Rübsam M, Lin EW, Has C, Omary MB, Niessen CM, Magin TM. Kinase Inhibition by PKC412 Prevents Epithelial Sheet Damage in Autosomal Dominant Epidermolysis Bullosa Simplex through Keratin and Cell Contact Stabilization. J Invest Dermatol 2022; 142:3282-3293. [PMID: 35691363 DOI: 10.1016/j.jid.2022.05.1088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 04/24/2022] [Accepted: 05/22/2022] [Indexed: 01/05/2023]
Abstract
Epidermolysis bullosa simplex (EBS) is a severe and potentially life-threatening disorder for which no adequate therapy exists. Most cases are caused by dominant sequence variations in keratin genes K5 or K14, leading to the formation of cytoplasmic keratin aggregates, profound keratinocyte fragility, and cytolysis. We hypothesized that pharmacological reduction of keratin aggregates, which compromise keratinocyte integrity, represents a viable strategy for the treatment of EBS. In this study, we show that the multikinase inhibitor PKC412, which is currently in clinical use for acute myeloid leukemia and advanced systemic mastocytosis, reduced keratin aggregation by 40% in patient-derived K14.R125C EBS-associated keratinocytes. Using a combination of epithelial shear stress assay and real-time impedance spectroscopy, we show that PKC412 restored intercellular adhesion. Molecularly, global phosphoproteomic analysis together with immunoblots using phosphoepitope-specific antibodies revealed that PKC412 treatment altered phosphorylated sites on keratins and desmoplakin. Thus, our data provide a proof of concept to repurpose existing drugs for the targeted treatment of EBS and showcase how one broad-range kinase inhibitor reduced keratin filament aggregation in patient-derived EBS keratinocytes and the fragility of EBS cell monolayers. Our study paves the way for a clinical trial using PKC412 for systemic or local application in patients with EBS.
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Affiliation(s)
- Katrin Rietscher
- Institute of Biology, Division of Cell and Developmental Biology, Leipzig University, Leipzig, Germany.
| | - Heinz-Georg Jahnke
- Division of Molecular Biological-Biochemical Processing Technology, Center for Biotechnology and Biomedicine, Leipzig University, Leipzig, Germany
| | - Matthias Rübsam
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Department Cell Biology of the Skin, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Eric W Lin
- Division of Gastroenterology and Hepatology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Cristina Has
- Department of Dermatology, Medical Center, University of Freiburg, Freiburg, Germany
| | - M Bishr Omary
- Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, New Jersey, USA; Robert Wood Johnson Medical School, Rutgers University, New Brunswick, New Jersey, USA
| | - Carien M Niessen
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Department Cell Biology of the Skin, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Thomas M Magin
- Institute of Biology, Division of Cell and Developmental Biology, Leipzig University, Leipzig, Germany
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2
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Chen F, Yao L, Zhang X, Gu Y, Yu H, Yao Z, Zhang J, Li M. Damaged Keratin Filament Network Caused by KRT5 Mutations in Localized Recessive Epidermolysis Bullosa Simplex. Front Genet 2021; 12:736610. [PMID: 34912369 PMCID: PMC8667171 DOI: 10.3389/fgene.2021.736610] [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: 07/05/2021] [Accepted: 10/28/2021] [Indexed: 11/21/2022] Open
Abstract
Epidermolysis bullosa simplex (EBS) is a blistering dermatosis that is mostly caused by dominant mutations in KRT5 and KRT14. In this study, we investigated one patient with localized recessive EBS caused by novel homozygous c.1474T > C mutations in KRT5. Biochemical experiments showed a mutation-induced alteration in the keratin 5 structure, intraepidermal blisters, and collapsed keratin intermediate filaments, but no quantitative change at the protein levels and interaction between keratin 5 and keratin 14. Moreover, we found that MAPK signaling was inhibited, while desmosomal protein desmoglein 1 (DSG1) was upregulated upon KRT5 mutation. Inhibition of EGFR phosphorylation upregulated DSG1 levels in an in vitro model. Collectively, our findings suggest that this mutation leads to localized recessive EBS and that keratin 5 is involved in maintaining DSG1 via activating MAPK signaling.
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Affiliation(s)
- Fuying Chen
- Department of Dermatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Institute of Dermatology, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Lei Yao
- Experiment Medicine Center, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Academician (Expert) Workstation of Sichuan Province, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Xue Zhang
- Department of Dermatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Institute of Dermatology, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yan Gu
- Department of Dermatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Institute of Dermatology, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Hong Yu
- Department of Dermatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Zhirong Yao
- Department of Dermatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Institute of Dermatology, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jia Zhang
- Department of Dermatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Institute of Dermatology, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Ming Li
- Department of Dermatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Institute of Dermatology, Shanghai Jiaotong University School of Medicine, Shanghai, China
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3
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Evtushenko NA, Beilin AK, Kosykh AV, Vorotelyak EA, Gurskaya NG. Keratins as an Inflammation Trigger Point in Epidermolysis Bullosa Simplex. Int J Mol Sci 2021; 22:ijms222212446. [PMID: 34830328 PMCID: PMC8624175 DOI: 10.3390/ijms222212446] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 12/21/2022] Open
Abstract
Epidermolysis bullosa simplex (EBS) is a group of inherited keratinopathies that, in most cases, arise due to mutations in keratins and lead to intraepidermal ruptures. The cellular pathology of most EBS subtypes is associated with the fragility of the intermediate filament network, cytolysis of the basal layer of the epidermis, or attenuation of hemidesmosomal/desmosomal components. Mutations in keratins 5/14 or in other genes that encode associated proteins induce structural disarrangements of different strengths depending on their locations in the genes. Keratin aggregates display impaired dynamics of assembly and diminished solubility and appear to be the trigger for endoplasmic reticulum (ER) stress upon being phosphorylated by MAPKs. Global changes in cellular signaling mainly occur in cases of severe dominant EBS mutations. The spectrum of changes initiated by phosphorylation includes the inhibition of proteasome degradation, TNF-α signaling activation, deregulated proliferation, abnormal cell migration, and impaired adherence of keratinocytes. ER stress also leads to the release of proinflammatory danger-associated molecular pattern (DAMP) molecules, which enhance avalanche-like inflammation. Many instances of positive feedback in the course of cellular stress and the development of sterile inflammation led to systemic chronic inflammation in EBS. This highlights the role of keratin in the maintenance of epidermal and immune homeostasis.
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Affiliation(s)
- Nadezhda A. Evtushenko
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, Ostrovityanova 1, 117997 Moscow, Russia; (N.A.E.); (A.K.B.); (A.V.K.)
| | - Arkadii K. Beilin
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, Ostrovityanova 1, 117997 Moscow, Russia; (N.A.E.); (A.K.B.); (A.V.K.)
- Koltzov Institute of Developmental Biology of Russian Academy of Sciences, Vavilova 26, 119334 Moscow, Russia;
| | - Anastasiya V. Kosykh
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, Ostrovityanova 1, 117997 Moscow, Russia; (N.A.E.); (A.K.B.); (A.V.K.)
| | - Ekaterina A. Vorotelyak
- Koltzov Institute of Developmental Biology of Russian Academy of Sciences, Vavilova 26, 119334 Moscow, Russia;
| | - Nadya G. Gurskaya
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, Ostrovityanova 1, 117997 Moscow, Russia; (N.A.E.); (A.K.B.); (A.V.K.)
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Miklukho-Maklaya 16/10, 117997 Moscow, Russia
- Correspondence:
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4
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Tan TS, Common JEA, Lim JSY, Badowski C, Firdaus MJ, Leonardi SS, Lane EB. A cell-based drug discovery assay identifies inhibition of cell stress responses as a new approach to treatment of epidermolysis bullosa simplex. J Cell Sci 2021; 134:272475. [PMID: 34643242 PMCID: PMC8542385 DOI: 10.1242/jcs.258409] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 09/07/2021] [Indexed: 11/20/2022] Open
Abstract
In the skin fragility disorder epidermolysis bullosa simplex (EBS), mutations in keratin 14 (K14, also known as KRT14) or keratin 5 (K5, also known as KRT5) lead to keratinocyte rupture and skin blistering. Severe forms of EBS are associated with cytoplasmic protein aggregates, with elevated kinase activation of ERK1 and ERK2 (ERK1/2; also known as MAPK3 and MAPK1, respectively), suggesting intrinsic stress caused by misfolded keratin protein. Human keratinocyte EBS reporter cells stably expressing GFP-tagged EBS-mimetic mutant K14 were used to optimize a semi-automated system to quantify the effects of test compounds on keratin aggregates. Screening of a protein kinase inhibitor library identified several candidates that reduced aggregates and impacted on epidermal growth factor receptor (EGFR) signalling. EGF ligand exposure induced keratin aggregates in EBS reporter keratinocytes, which was reversible by EGFR inhibition. EBS keratinocytes treated with a known EGFR inhibitor, afatinib, were driven out of activation and towards quiescence with minimal cell death. Aggregate reduction was accompanied by denser keratin filament networks with enhanced intercellular cohesion and resilience, which when extrapolated to a whole tissue context would predict reduced epidermal fragility in EBS patients. This assay system provides a powerful tool for discovery and development of new pathway intervention therapeutic avenues for EBS.
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Affiliation(s)
- Tong San Tan
- Skin Research Institute of Singapore, A*STAR, Immunos Building, 8A Biomedical Grove, Singapore138648.,Institute of Medical Biology, A*STAR, Immunos Building, 8A Biomedical Grove, Singapore138648
| | - John E A Common
- Skin Research Institute of Singapore, A*STAR, Immunos Building, 8A Biomedical Grove, Singapore138648.,Institute of Medical Biology, A*STAR, Immunos Building, 8A Biomedical Grove, Singapore138648
| | - John S Y Lim
- A*STAR Microscopy Platform, Immunos Building, 8A Biomedical Grove, Singapore138648
| | - Cedric Badowski
- Institute of Medical Biology, A*STAR, Immunos Building, 8A Biomedical Grove, Singapore138648
| | - Muhammad Jasrie Firdaus
- Skin Research Institute of Singapore, A*STAR, Immunos Building, 8A Biomedical Grove, Singapore138648.,Institute of Medical Biology, A*STAR, Immunos Building, 8A Biomedical Grove, Singapore138648
| | - Steven S Leonardi
- Skin Research Institute of Singapore, A*STAR, Immunos Building, 8A Biomedical Grove, Singapore138648
| | - E Birgitte Lane
- Skin Research Institute of Singapore, A*STAR, Immunos Building, 8A Biomedical Grove, Singapore138648.,Institute of Medical Biology, A*STAR, Immunos Building, 8A Biomedical Grove, Singapore138648
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5
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Jiang X, Zhu Y, Sun H, Gu F. A Novel Mutation p.L461P in KRT5 Causing Localized Epidermolysis Bullosa Simplex. Ann Dermatol 2020; 33:11-17. [PMID: 33911807 PMCID: PMC7875216 DOI: 10.5021/ad.2021.33.1.11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/29/2020] [Accepted: 06/17/2020] [Indexed: 11/08/2022] Open
Abstract
Background Epidermolysis bullosa (EB) is a rare genetic disease with widely different clinical manifestations, but the relationship between genotype and phenotype is not fully understood. In the present study, we recruited a Chinese family in which two members had been diagnosed with localized EB simplex (EBS), with clinical manifestation, including blisters and erosions on the soles of the feet since infancy. Objective To identify and confirm the genetic variation in a Chinese family diagnosed as localized EBS. Methods Our study included two patients, other healthy members of the family, and 100 normal controls. Genomic DNA samples were isolated from each participant, and then polymerase chain reaction (PCR) direct sequencing was performed. Results The results of PCR direct sequencing revealed a novel heterozygous missense mutation in codon 461 of exon 7 of KRT5 (c.1382T>C), which led to an amino acid change (p.L461P) in the patients with EBS but was absent in unaffected family members and 100 unrelated control samples. Conclusion The present study broadens the mutational spectrum of EBS, and this knowledge could be harnessed for prenatal screening, gene diagnosis, and gene therapy for localized EBS.
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Affiliation(s)
- Xin Jiang
- Department of Dermatology, Tongling People's Hospital, Anhui, China
| | - Yingyu Zhu
- Department of Dermatology, Tongling People's Hospital, Anhui, China
| | - Huihui Sun
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China.,Genetic Disease Center, School of Ophthalmology & Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Feng Gu
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China.,Genetic Disease Center, School of Ophthalmology & Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
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6
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Sajini AA, Choudhury NR, Wagner RE, Bornelöv S, Selmi T, Spanos C, Dietmann S, Rappsilber J, Michlewski G, Frye M. Loss of 5-methylcytosine alters the biogenesis of vault-derived small RNAs to coordinate epidermal differentiation. Nat Commun 2019; 10:2550. [PMID: 31186410 PMCID: PMC6560067 DOI: 10.1038/s41467-019-10020-7] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 04/09/2019] [Indexed: 12/20/2022] Open
Abstract
The presence and absence of RNA modifications regulates RNA metabolism by modulating the binding of writer, reader, and eraser proteins. For 5-methylcytosine (m5C) however, it is largely unknown how it recruits or repels RNA-binding proteins. Here, we decipher the consequences of m5C deposition into the abundant non-coding vault RNA VTRNA1.1. Methylation of cytosine 69 in VTRNA1.1 occurs frequently in human cells, is exclusively mediated by NSUN2, and determines the processing of VTRNA1.1 into small-vault RNAs (svRNAs). We identify the serine/arginine rich splicing factor 2 (SRSF2) as a novel VTRNA1.1-binding protein that counteracts VTRNA1.1 processing by binding the non-methylated form with higher affinity. Both NSUN2 and SRSF2 orchestrate the production of distinct svRNAs. Finally, we discover a functional role of svRNAs in regulating the epidermal differentiation programme. Thus, our data reveal a direct role for m5C in the processing of VTRNA1.1 that involves SRSF2 and is crucial for efficient cellular differentiation.
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Affiliation(s)
- Abdulrahim A Sajini
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK
- Department of Biomedical Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates
- Department of Medical Laboratory Technology, University of Tabuk, Tabuk, P.O. Box 71491, Saudi Arabia
| | - Nila Roy Choudhury
- Division of Infection and Pathway Medicine, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Rebecca E Wagner
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK
| | - Susanne Bornelöv
- Wellcome MRC Cambridge Stem Cell Institute, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - Tommaso Selmi
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK
| | - Christos Spanos
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Sabine Dietmann
- Wellcome MRC Cambridge Stem Cell Institute, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - Juri Rappsilber
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK
- Department of Biotechnology, Technische Universität Berlin, Gustav-Meyer-Allee 25, 13355, Berlin, Germany
| | - Gracjan Michlewski
- Division of Infection and Pathway Medicine, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK.
- ZJU-UoE Institute, Zhejiang University, 718 East Haizhou Road, Haining, Zhejiang, 314400, P.R. China.
| | - Michaela Frye
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK.
- German Cancer Research Centre (Deutsches Krebsforschungszentrum, DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.
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7
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Spörrer M, Prochnicki A, Tölle RC, Nyström A, Esser PR, Homberg M, Athanasiou I, Zingkou E, Schilling A, Gerum R, Thievessen I, Winter L, Bruckner-Tuderman L, Fabry B, Magin TM, Dengjel J, Schröder R, Kiritsi D. Treatment of keratinocytes with 4-phenylbutyrate in epidermolysis bullosa: Lessons for therapies in keratin disorders. EBioMedicine 2019; 44:502-515. [PMID: 31078522 PMCID: PMC6603805 DOI: 10.1016/j.ebiom.2019.04.062] [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: 11/19/2018] [Revised: 04/30/2019] [Accepted: 04/30/2019] [Indexed: 12/18/2022] Open
Abstract
Background Missense mutations in keratin 5 and 14 genes cause the severe skin fragility disorder epidermolysis bullosa simplex (EBS) by collapsing of the keratin cytoskeleton into cytoplasmic protein aggregates. Despite intense efforts, no molecular therapies are available, mostly due to the complex phenotype of EBS, comprising cell fragility, diminished adhesion, skin inflammation and itch. Methods We extensively characterized KRT5 and KRT14 mutant keratinocytes from patients with severe generalized EBS following exposure to the chemical chaperone 4-phenylbutyrate (4-PBA). Findings 4-PBA diminished keratin aggregates within EBS cells and ameliorated their inflammatory phenotype. Chemoproteomics of 4-PBA-treated and untreated EBS cells revealed reduced IL1β expression- but also showed activation of Wnt/β-catenin and NF-kB pathways. The abundance of extracellular matrix and cytoskeletal proteins was significantly altered, coinciding with diminished keratinocyte adhesion and migration in a 4-PBA dose-dependent manner. Interpretation Together, our study reveals a complex interplay of benefits and disadvantages that challenge the use of 4-PBA in skin fragility disorders.
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Affiliation(s)
- Marina Spörrer
- Department of Physics, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Ania Prochnicki
- Institute of Neuropathology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Regine C Tölle
- Department of Biology, University of Fribourg, Switzerland
| | - Alexander Nyström
- Department of Dermatology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Philipp R Esser
- Department of Dermatology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Melanie Homberg
- Institute of Biology and SIKT, University of Leipzig, Leipzig, Germany
| | - Ioannis Athanasiou
- Department of Dermatology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Eleni Zingkou
- Department of Dermatology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Achim Schilling
- Department of Physics, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany; Experimental Otolaryngology, ENT Hospital, Head and Neck Surgery, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Richard Gerum
- Department of Physics, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Ingo Thievessen
- Department of Physics, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Lilli Winter
- Institute of Neuropathology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Leena Bruckner-Tuderman
- Department of Dermatology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ben Fabry
- Department of Physics, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Thomas M Magin
- Institute of Biology and SIKT, University of Leipzig, Leipzig, Germany
| | - Jörn Dengjel
- Department of Biology, University of Fribourg, Switzerland; Department of Dermatology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Rolf Schröder
- Institute of Neuropathology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Dimitra Kiritsi
- Department of Dermatology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
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8
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Khani P, Ghazi F, Zekri A, Nasri F, Behrangi E, Aghdam AM, Mirzaei H. Keratins and epidermolysis bullosa simplex. J Cell Physiol 2018; 234:289-297. [PMID: 30078200 DOI: 10.1002/jcp.26898] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 06/12/2018] [Indexed: 11/10/2022]
Abstract
Keratin intermediate filaments play an important role in maintaining the integrity of the skin structure. Understanding the importance of this subject is possible with the investigation of keratin defects in epidermolysis bullosa simplex (EBS). Nowadays, in addition to clinical criteria, new molecular diagnostic methods, such as next generation sequencing, can help to distinguish the subgroups of EBS more precisely. Because the most important and most commonly occurring molecular defects in these patients are the defects of keratins 5 and14 (KRT5 and KRT14), comprehending the nature structure of these proteins and their involved processes can be very effective in understanding the pathophysiology of this disease and providing new and effective therapeutic platforms to treat it. Here, we summarized the various aspects of the presence of KRT5 and KRT14 in the epidermis, their relation to the incidence and severity of EBS phenotypes, and the processes with which these proteins can affect them.
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Affiliation(s)
- Pouria Khani
- Department of Medical Genetics and Molecular Biology, Faculty of Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran
| | - Farideh Ghazi
- Department of Medical Genetics and Molecular Biology, Faculty of Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran
| | - Ali Zekri
- Department of Medical Genetics and Molecular Biology, Faculty of Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran
| | - Farzad Nasri
- Department of Medical Immunology, Faculty of Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran
| | - Elham Behrangi
- Department of Dermatology and Laser Surgery, Clinical Research Center, Rasoul-e-Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Arad Mobasher Aghdam
- School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamed Mirzaei
- Department of Medical Biotechnology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
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9
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Elango T, Sun J, Zhu C, Zhou F, Zhang Y, Sun L, Yang S, Zhang X. Mutational analysis of epidermal and hyperproliferative type I keratins in mild and moderate psoriasis vulgaris patients: a possible role in the pathogenesis of psoriasis along with disease severity. Hum Genomics 2018; 12:27. [PMID: 29784039 PMCID: PMC5963134 DOI: 10.1186/s40246-018-0158-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 05/09/2018] [Indexed: 02/08/2023] Open
Abstract
Background Mutations in keratin proteins have been vastly associated with a wide array of genodermatoses; however, mutations of keratins in psoriasis have not been fully investigated. The main aim of the current research was to identify the mutation in K14, K10, K16, and K17 genes in two stages of psoriasis patients. Methods Ninety-six psoriatic skin biopsies were collected. mRNA transcript of K14, K10, K16, and K17 was prepared, amplified, and sequenced. Sanger sequences of all keratins were further validated for mutational analysis using Mutation Surveyor and Alamut Visual. Then, in silico analysis of protein stability and protein and gene expression of all keratins was performed and validated. Results Out of 44 mutations, about 75% of keratins are highly pathogenic and deleterious. Remaining 25% mutations are less pathogenic and tolerated in nature. In these 33 deleterious mutations were immensely found to decrease keratin protein stability. We also found a correlation between keratin and Psoriasis Area and Severity Index score which added that alteration in keratin gene in skin causes severity of psoriasis. Conclusions We strongly concluded that acanthosis and abnormal terminal differentiation was mainly due to the mutation in epidermal keratins. In turn, disease severity and relapsing of psoriasis are mainly due to the mutation of hyperproliferative keratins. These novel keratin mutations in psoriatic epidermis might be one of the causative factors for psoriasis. Electronic supplementary material The online version of this article (10.1186/s40246-018-0158-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tamilselvi Elango
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University, Hefei, China. .,Anhui Medical University, 81 Meishan Road, Hefei, Anhui Province, China.
| | - Jingying Sun
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University, Hefei, China
| | - Caihong Zhu
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University, Hefei, China
| | - Fusheng Zhou
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University, Hefei, China
| | - Yaohua Zhang
- Institute of Dermatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Liangdan Sun
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University, Hefei, China.,Key Laboratory of Dermatology, Ministry of Education, Anhui Medical University, Hefei, China.,Collaborative Innovation Center for Complex and Severe Dermatosis, Anhui Medical University, Hefei, China
| | - Sen Yang
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University, Hefei, China.,Key Laboratory of Dermatology, Ministry of Education, Anhui Medical University, Hefei, China.,Collaborative Innovation Center for Complex and Severe Dermatosis, Anhui Medical University, Hefei, China
| | - Xuejun Zhang
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University, Hefei, China. .,Key Laboratory of Dermatology, Ministry of Education, Anhui Medical University, Hefei, China. .,Collaborative Innovation Center for Complex and Severe Dermatosis, Anhui Medical University, Hefei, China. .,Institute of Dermatology, Huashan Hospital, Fudan University, Shanghai, China. .,Anhui Medical University, 81 Meishan Road, Hefei, Anhui Province, China.
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10
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Kippenberger S, Kleemann J, Meissner M, Steinhorst K, Müller J, Zouboulis CC, Kaufmann R, Zöller N. Activation of PKB/Akt and p44/42 by mechanical stretch utilizes desmosomal structures and the keratin filament. J Dermatol Sci 2017; 89:241-247. [PMID: 29198699 DOI: 10.1016/j.jdermsci.2017.11.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 11/17/2017] [Accepted: 11/23/2017] [Indexed: 12/19/2022]
Abstract
BACKGROUND Mechanical stress is an ubiquitous challenge of human cells with fundamental impact on cell physiology. Previous studies have shown that stretching promotes signalling cascades involved in proliferation and tissue enlargement. OBJECTIVE The present study is dedicated to learn more about cellular structures contributing to perception and signal transmission of cell stretch. In particular, we hypothesized that desmosmal contacts and the adjacent keratin filament build an intercellular matrix providing information about the mechanical load. METHODS Epidermal cells with different keratin equipment were seeded on flexible silicon dishes and stretched. As read out parameter the activation of PKB/Akt and p44/42 was monitored by Western blotting. Likewise desomosomal contacts were manipulated by depletion or addition of calcium. Moreover, desmoglein 3 and desmocollin 3 were blocked by either specific antibodies or siRNA. RESULTS It was found that the omission of calcium from the medium, a necessary cofactor for desmosomal cadherins, inhibited stretch mediated activation of PKB/Akt and p44/42. The relevance of desmosomes in this context was further substantiated by experiments using a desmoglein 3 blocking antibody (AK23) and siRNA against desmocollin 3. Moreover, disruption of the keratin filament by sodium orthovanadate also abrogates PKB/Akt and p44/42 activation in response to stretch. Likewise, KEB-7 keratinocytes harbouring a mutation in the keratin 14 gene and genetically modified keratinocytes devoid of any keratin show an altered signalling after stretch indicating the relevance of the keratin filament in this context. CONCLUSION Besides their important role in cell architecture our results identify desmosomes and keratins as mechanosensing structures.
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Affiliation(s)
- Stefan Kippenberger
- Clinic of Dermatology, Venereology and Allergology, Johann Wolfgang Goethe University, Frankfurt/Main, Germany.
| | - Johannes Kleemann
- Clinic of Dermatology, Venereology and Allergology, Johann Wolfgang Goethe University, Frankfurt/Main, Germany
| | - Markus Meissner
- Clinic of Dermatology, Venereology and Allergology, Johann Wolfgang Goethe University, Frankfurt/Main, Germany
| | - Katja Steinhorst
- Clinic of Dermatology, Venereology and Allergology, Johann Wolfgang Goethe University, Frankfurt/Main, Germany
| | - Jutta Müller
- Clinic of Dermatology, Venereology and Allergology, Johann Wolfgang Goethe University, Frankfurt/Main, Germany
| | - Christos C Zouboulis
- Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Brandenburg Medical School Theodor Fontane, Dessau, Germany
| | - Roland Kaufmann
- Clinic of Dermatology, Venereology and Allergology, Johann Wolfgang Goethe University, Frankfurt/Main, Germany
| | - Nadja Zöller
- Clinic of Dermatology, Venereology and Allergology, Johann Wolfgang Goethe University, Frankfurt/Main, Germany
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11
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Keratin gene mutations influence the keratinocyte response to DNA damage and cytokine induced apoptosis. Arch Dermatol Res 2017. [DOI: 10.1007/s00403-017-1757-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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12
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Chee MK, Jo SK, Sohn KC, Kim CD, Lee JH, Lee YH. Effects of Brn2 overexpression on eccrine sweat gland development in the mouse paw. Biochem Biophys Res Commun 2017. [PMID: 28648603 DOI: 10.1016/j.bbrc.2017.06.138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Eccrine sweat glands regulate body temperature by secreting water and electrolytes. In humans, eccrine sweat glands are ubiquitous in the skin, except in the lips and external genitalia. In mice, eccrine sweat glands are present only in the paw pad. Brn2 is a protein belonging to a large family of transcription factors. A few studies have examined Brn2 in melanoma cells and epidermal keratinocytes. This study investigated changes in the skin in the K5-Brn2 transgenic mouse, which overexpresses Brn2 and contains the keratin 5 promotor. Interestingly, the volume of eccrine sweat glands was reduced markedly in the K5-Brn2 transgenic mouse compared with the wild-type, while the expression of aquaporin 5, important molecule in sweat secretion, was increased in each sweat gland cell, probably to compensate for the reduction in gland development. However, sweating response to a pilocarpine injection in the hind paw was significantly decreased in the K5-Brn2 transgenic mouse compared with the wild-type. The paw epidermis was thicker in the K5-Brn2 transgenic mouse compared with the wild-type. Taken together, eccrine sweat gland development and sweat secretion were suppressed markedly in the K5-Brn2 transgenic mouse. These results may be associated with dominant development of the epidermis by Brn2 overexpression in the paw skin.
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Affiliation(s)
- Min Keun Chee
- Department of Anatomy, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Seong Kyeong Jo
- Department of Anatomy, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Kyung Cheol Sohn
- Department of Dermatology, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Chang Deok Kim
- Department of Dermatology, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Jeung-Hoon Lee
- Department of Dermatology, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Young Ho Lee
- Department of Anatomy, College of Medicine, Chungnam National University, Daejeon, South Korea.
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13
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Salas PJ, Forteza R, Mashukova A. Multiple roles for keratin intermediate filaments in the regulation of epithelial barrier function and apico-basal polarity. Tissue Barriers 2016; 4:e1178368. [PMID: 27583190 PMCID: PMC4993576 DOI: 10.1080/21688370.2016.1178368] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/05/2016] [Accepted: 04/07/2016] [Indexed: 12/27/2022] Open
Abstract
As multicellular organisms evolved a family of cytoskeletal proteins, the keratins (types I and II) expressed in epithelial cells diversified in more than 20 genes in vertebrates. There is no question that keratin filaments confer mechanical stiffness to cells. However, such a number of genes can hardly be explained by evolutionary advantages in mechanical features. The use of transgenic mouse models has revealed unexpected functional relationships between keratin intermediate filaments and intracellular signaling. Accordingly, loss of keratins or mutations in keratins that cause or predispose to human diseases, result in increased sensitivity to apoptosis, regulation of innate immunity, permeabilization of tight junctions, and mistargeting of apical proteins in different epithelia. Precise mechanistic explanations for these phenomena are still lacking. However, immobilization of membrane or cytoplasmic proteins, including chaperones, on intermediate filaments (“scaffolding”) appear as common molecular mechanisms and may explain the need for so many different keratin genes in vertebrates.
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Affiliation(s)
- Pedro J Salas
- Department of Cell Biology, Miller School of Medicine, University of Miami , Miami, FL, USA
| | - Radia Forteza
- Department of Cell Biology, Miller School of Medicine, University of Miami , Miami, FL, USA
| | - Anastasia Mashukova
- Department of Cell Biology, Miller School of Medicine, University of Miami, Miami, FL, USA; Department of Physiology, Nova Southeastern University, Fort Lauderdale, FL, USA
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14
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Tan TS, Ng YZ, Badowski C, Dang T, Common JEA, Lacina L, Szeverényi I, Lane EB. Assays to Study Consequences of Cytoplasmic Intermediate Filament Mutations: The Case of Epidermal Keratins. Methods Enzymol 2016; 568:219-53. [PMID: 26795473 DOI: 10.1016/bs.mie.2015.09.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Abstract
The discovery of the causative link between keratin mutations and a growing number of human diseases opened the way for a better understanding of the function of the whole intermediate filament families of cytoskeleton proteins. This chapter describes analytical approaches to identification and interpretation of the consequences of keratin mutations, from the clinical and diagnostic level to cells in tissue culture. Intermediate filament pathologies can be accurately diagnosed from skin biopsies and DNA samples. The Human Intermediate Filament Database collates reported mutations in intermediate filament genes and their diseases, and can help clinicians to establish accurate diagnoses, leading to disease stratification for genetic counseling, optimal care delivery, and future mutation-aligned new therapies. Looking at the best-studied keratinopathy, epidermolysis bullosa simplex, the generation of cell lines mimicking keratinopathies is described, in which tagged mutant keratins facilitate live-cell imaging to make use of today's powerful enhanced light microscopy modalities. Cell stress assays such as cell spreading and cell migration in scratch wound assays can interrogate the consequences of the compromised cytoskeletal network. Application of extrinsic stresses, such as heat, osmotic, or mechanical stress, can enhance the differentiation of mutant keratin cells from wild-type cells. To bring the experiments to the next level, 3D organotypic human cultures can be generated, and even grafted onto the backs of immunodeficient mice for greater in vivo relevance. While development of these assays has focused on mutant K5/K14 cells, the approaches are often applicable to mutations in other intermediate filaments, reinforcing fundamental commonalities in spite of diverse clinical pathologies.
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Affiliation(s)
| | | | | | - Tram Dang
- Institute of Medical Biology, Singapore
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15
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Herzog J, Rid R, Wagner M, Hundsberger H, Eger A, Bauer J, Önder K. Whole-transcriptome gene expression profiling in an epidermolysis bullosa simplex Dowling-Meara model keratinocyte cell line uncovered novel, potential therapeutic targets and affected pathways. BMC Res Notes 2015; 8:785. [PMID: 26666517 PMCID: PMC4678661 DOI: 10.1186/s13104-015-1783-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/01/2015] [Indexed: 12/28/2022] Open
Abstract
Background To be able to develop effective therapeutics for epidermolysis bullosa simplex (EBS), it is necessary to elucidate the molecular pathomechanisms that give rise to the disease’s characteristic severe skin-blistering phenotype. Results Starting with a whole-transcriptome microarray analysis of an EBS Dowling-Meara model cell line (KEB7), we identified 207 genes showing differential expression relative to control keratinocytes. A complementary qRT-PCR study of 156 candidates confirmed 76.58 % of the selected genes to be significantly up-regulated or down-regulated (p-value <0.05) within biological replicates. Our hit list contains previously identified genes involved in epithelial cell proliferation, cell-substrate adhesion, and responses to diverse biological stimuli. In addition, we identified novel candidate genes and potential affected pathways not previously considered as relevant to EBS pathology. Conclusions Our results broaden our understanding of the molecular processes dysregulated in EBS. Electronic supplementary material The online version of this article (doi:10.1186/s13104-015-1783-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Julia Herzog
- Division of Molecular Dermatology, Department of Dermatology, Paracelsus Private Medical University Salzburg, Salzburg, Austria.
| | - Raphaela Rid
- Division of Molecular Dermatology, Department of Dermatology, Paracelsus Private Medical University Salzburg, Salzburg, Austria.
| | - Martin Wagner
- Division of Molecular Dermatology, Department of Dermatology, Paracelsus Private Medical University Salzburg, Salzburg, Austria.
| | - Harald Hundsberger
- Department of Medical and Pharmaceutical Biotechnology, University of Applied Sciences, Krems, Austria.
| | - Andreas Eger
- Department of Medical and Pharmaceutical Biotechnology, University of Applied Sciences, Krems, Austria.
| | - Johann Bauer
- Division of Molecular Dermatology, Department of Dermatology, Paracelsus Private Medical University Salzburg, Salzburg, Austria.
| | - Kamil Önder
- Division of Molecular Dermatology, Department of Dermatology, Paracelsus Private Medical University Salzburg, Salzburg, Austria.
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16
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Jahnel O, Hoffmann B, Merkel R, Bossinger O, Leube RE. Mechanical Probing of the Intermediate Filament-Rich Caenorhabditis Elegans Intestine. Methods Enzymol 2015; 568:681-706. [PMID: 26795489 DOI: 10.1016/bs.mie.2015.08.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
It is commonly accepted that intermediate filaments have an important mechanical function. This function relies not only on intrinsic material properties but is also determined by dynamic interactions with other cytoskeletal filament systems, distinct cell adhesion sites, and cellular organelles which are fine-tuned by multiple signaling pathways. While aspects of these properties and processes can be studied in vitro, their full complexity can only be understood in a viable tissue context. Yet, suitable and easily accessible model systems for monitoring tissue mechanics at high precision are rare. We show that the dissected intestine of the genetic model organism Caenorhabditis elegans fulfills this requirement. The 20 intestinal cells, which are arranged in an invariant fashion, are characterized by a dense subapical mesh of intermediate filaments that are attached to the C. elegans apical junction. We present procedures to visualize details of the characteristic intermediate filament-junctional complex arrangement in living animals. We then report on methods to prepare intestines with a fully intact intermediate filament cytoskeleton and detail procedures to assess their viability. A dual micropipette assay is described to measure mechanical properties of the dissected intestine while monitoring the spatial arrangement of the intermediate filament system. Advantages of this approach are (i) the high reproducibility of measurements because of the uniform architecture of the intestine and (ii) the high degree of accessibility allowing not only mechanical manipulation of an intact tissue but also control of culture medium composition and addition of drugs as well as visualization of cell structures. With this method, examination of worms carrying mutations in the intermediate filament system, its interacting partners and its regulators will become feasible.
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Affiliation(s)
- Oliver Jahnel
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany
| | - Bernd Hoffmann
- Institute of Complex Systems, ICS-7: Biomechanics, Jülich, Germany
| | - Rudolf Merkel
- Institute of Complex Systems, ICS-7: Biomechanics, Jülich, Germany
| | - Olaf Bossinger
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany
| | - Rudolf E Leube
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany.
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17
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Apocytolysis, a proposed mechanism of blister formation in epidermolysis bullosa simplex. Arch Dermatol Res 2015; 307:371-7. [PMID: 25822146 DOI: 10.1007/s00403-015-1560-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 03/14/2015] [Accepted: 03/24/2015] [Indexed: 02/03/2023]
Abstract
Epidermolysis bullosa simplex (EBS) is caused by keratin 5 and 14 mutations. In vitro studies revealed that susceptibility to caspase 8-mediated apoptosis is increased in keratin 14 mutated keratinocytes. We aimed to investigate the role of apoptotic/inflammatory pathways in the pathogenesis of EBS by studying the expression of caspase 8 in lesional and non-lesional skin compared to controls. Ten EBS patients proved by electron microscopy and five age and sex matched healthy volunteers were the subjects of this case control study. Caspase 8 expression was studied by immunohistochemistry. Caspase 8 expression in lesional and non-lesional skin was significantly higher than in controls (p < 0.01 and p = 0.013, respectively) with no significant difference between lesional and non-lesional skin. Lesional skin had significantly higher density of dermal infiltrate (p = 0.02). Caspase 8 expression in lesional skin was significantly correlated with the extent of the disease, rate of blistering, and density of dermal infiltrate (r = 0.835; p = 0.003, r = 0.889; p = 0.001 and r = 0.776; p = 0.008 respectively). Caspase 8-mediated apoptosis is an integral component of an orchestra of events conducted by keratin mutation. Apo-cytolysis is proposed to better describe the mechanism of blistering in EBS. The small number of cases is a limitation.
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18
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Liu H, Jian Q, Xue K, Ma C, Xie F, Wang R, Liao W, Liu Y, Chi S, Li C. The MEK/ERK signalling cascade is required for sonic hedgehog signalling pathway-mediated enhancement of proliferation and inhibition of apoptosis in normal keratinocytes. Exp Dermatol 2014; 23:896-901. [PMID: 25256290 DOI: 10.1111/exd.12556] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2014] [Indexed: 12/24/2022]
Affiliation(s)
- Haiyan Liu
- Department of Dermatology; Xijing Hospital; the Fourth Military Medical University; Xi'an China
- Department of Dermatology; Lanzhou General Hospital, Lanzhou Military District; Lanzhou China
| | - Qiang Jian
- Department of Dermatology; Xijing Hospital; the Fourth Military Medical University; Xi'an China
| | - Ke Xue
- Department of Dermatology; Xijing Hospital; the Fourth Military Medical University; Xi'an China
| | - Cuiling Ma
- Department of Dermatology; Xijing Hospital; the Fourth Military Medical University; Xi'an China
| | - Fang Xie
- Department of Dermatology; Chinese People's Liberation Army General Hospital; Beijing China
| | - Rui Wang
- Department of Dermatology; Chinese People's Liberation Army General Hospital; Beijing China
| | - Wenjun Liao
- Department of Dermatology; Xijing Hospital; the Fourth Military Medical University; Xi'an China
| | - Yufeng Liu
- Department of Dermatology; Xijing Hospital; the Fourth Military Medical University; Xi'an China
| | - Sumin Chi
- Department of Physiology; the Fourth Military Medical University; Xi'an China
| | - Chengxin Li
- Department of Dermatology; Xijing Hospital; the Fourth Military Medical University; Xi'an China
- Department of Dermatology; Chinese People's Liberation Army General Hospital; Beijing China
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19
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Zupancic T, Stojan J, Lane EB, Komel R, Bedina-Zavec A, Liovic M. Intestinal cell barrier function in vitro is severely compromised by keratin 8 and 18 mutations identified in patients with inflammatory bowel disease. PLoS One 2014; 9:e99398. [PMID: 24915158 PMCID: PMC4051775 DOI: 10.1371/journal.pone.0099398] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 05/14/2014] [Indexed: 12/20/2022] Open
Abstract
Keratin 8 and 18 (K8/K18) mutations have been implicated in the aetiology of certain pathogenic processes of the liver and pancreas. While some K8 mutations (K8 G62C, K8 K464N) are also presumed susceptibility factors for inflammatory bowel disease (IBD), the only K18 mutation (K18 S230T) discovered so far in an IBD patient is thought to be a polymorphism. The aim of our study was to demonstrate that these mutations might also directly affect intestinal cell barrier function. Cell monolayers of genetically engineered human colonocytes expressing these mutations were tested for permeability, growth rate and resistance to heat-stress. We also calculated the change in dissociation constant (Kd, measure of affinity) each of these mutations introduces into the keratin protein, and present the first model of a keratin dimer L12 region with in silico clues to how the K18 S230T mutation may affect keratin function. Physiologically, these mutations cause up to 30% increase in paracellular permeability in vitro. Heat-stress induces little keratin clumping but instead cell monolayers peel off the surface suggesting a problem with cell junctions. K18 S230T has pronounced pathological effects in vitro marked by high Kd, low growth rate and increased permeability. The latter may be due to the altered distribution of tight junction components claudin-4 and ZO-1. This is the first time intestinal cells have been suggested also functionally impaired by K8/K18 mutations. Although an in vitro colonocyte model system does not completely mimic the epithelial lining of the intestine, nevertheless the data suggest that K8/K18 mutations may be also able to produce a phenotype in vivo.
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Affiliation(s)
- Tina Zupancic
- National Institute of Chemistry, Ljubljana, Slovenia
| | - Jure Stojan
- Medical Centre for Molecular Biology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | | | - Radovan Komel
- National Institute of Chemistry, Ljubljana, Slovenia
- Medical Centre for Molecular Biology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | | | - Mirjana Liovic
- National Institute of Chemistry, Ljubljana, Slovenia
- Medical Centre for Molecular Biology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- * E-mail:
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20
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Wagner M, Trost A, Hintner H, Bauer JW, Onder K. Imbalance of intermediate filament component keratin 14 contributes to increased stress signalling in epidermolysis bullosa simplex. Exp Dermatol 2013; 22:292-4. [PMID: 23528216 DOI: 10.1111/exd.12112] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/07/2013] [Indexed: 12/19/2022]
Abstract
An important characteristic of epidermolysis bullosa simplex Dowling-Meara (EBS-DM) keratinocytes is the increased level of Jun N-terminal kinase (JNK) stress signalling, which is thought to contribute to the disease phenotype. In this work, we report on the dramatic up-regulation of cytokeratin 14 (K14) in the EBS-DM model cell line KEB7 at both the transcriptional and translational levels, which is noteworthy because KEB7 patient cells are heterozygous for a missense mutation (R125P) in K14. By performing functional assays, we show a direct link between overexpressed wild-type K14 and increased JNK signalling in healthy, immortalized keratinocytes. This observation led us to hypothesize a positive feedback model in which mutant (R125P) K14 triggers JNK signalling, leading to increased AP1-dependent expression of K14, which in turn amplifies JNK signalling further. We therefore suggest that an imbalance of cytoplasmic K14 monomers and K14 incorporated into the intermediate filament (IF) network leads to elevated stress signalling, potentially altering IF dynamics by phosphorylation, which as a side effect, weakens EBS-DM keratinocytes.
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21
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Lettner T, Lang R, Klausegger A, Hainzl S, Bauer JW, Wally V. MMP-9 and CXCL8/IL-8 are potential therapeutic targets in epidermolysis bullosa simplex. PLoS One 2013; 8:e70123. [PMID: 23894602 PMCID: PMC3716611 DOI: 10.1371/journal.pone.0070123] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 06/15/2013] [Indexed: 11/30/2022] Open
Abstract
Epidermolysis bullosa refers to a group of genodermatoses that affects the integrity of epithelial layers, phenotypically resulting in severe skin blistering. Dowling-Meara, the major subtype of epidermolysis bullosa simplex, is inherited in an autosomal dominant manner and can be caused by mutations in either the keratin-5 (K5) or the keratin-14 (K14) gene. Currently, no therapeutic approach is known, and the main objective of this study was to identify novel therapeutic targets. We used microarray analysis, semi-quantitative real-time PCR, western blot and ELISA to identify differentially regulated genes in two K14 mutant cell lines carrying the mutations K14 R125P and K14 R125H, respectively. We found kallikrein-related peptidases and matrix metalloproteinases to be upregulated. We also found elevated expression of chemokines, and we observed deregulation of the Cdc42 pathway as well as aberrant expression of cytokeratins and junction proteins. We further demonstrated, that expression of these genes is dependent on interleukin-1 β signaling. To evaluate these data in vivo we analysed the blister fluids of epidermolysis bullosa simplex patients vs. healthy controls and identified matrix metalloproteinase-9 and the chemokine CXCL8/IL-8 as potential therapeutic targets.
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Affiliation(s)
- Thomas Lettner
- Division of Experimental Dermatology and EB House Austria, Salzburg, Austria.
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22
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Affiliation(s)
- Rebecca L Haines
- Epithelial Biology Group, Institute of Medical Biology, Immunos, Singapore
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23
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Chamcheu JC, Wood GS, Siddiqui IA, Syed DN, Adhami VM, Teng JM, Mukhtar H. Progress towards genetic and pharmacological therapies for keratin genodermatoses: current perspective and future promise. Exp Dermatol 2012; 21:481-9. [PMID: 22716242 PMCID: PMC3556927 DOI: 10.1111/j.1600-0625.2012.01534.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hereditary keratin disorders of the skin and its appendages comprise a large group of clinically heterogeneous disfiguring blistering and ichthyotic diseases, primarily characterized by the loss of tissue integrity, blistering and hyperkeratosis in severely affected tissues. Pathogenic mutations in keratins cause these afflictions. Typically, these mutations in concert with characteristic features have formed the basis for improved disease diagnosis, prognosis and most recently therapy development. Examples include epidermolysis bullosa simplex, keratinopathic ichthyosis, pachyonychia congenita and several other tissue-specific hereditary keratinopathies. Understanding the molecular and genetic events underlying skin dysfunction has initiated alternative treatment approaches that may provide novel therapeutic opportunities for affected patients. Animal and in vitro disease modelling studies have shed more light on molecular pathogenesis, further defining the role of keratins in disease processes and promoting the translational development of new gene and pharmacological therapeutic strategies. Given that the molecular basis for these monogenic disorders is well established, gene therapy and drug discovery targeting pharmacological compounds with the ability to reinforce the compromised cytoskeleton may lead to promising new therapeutic strategies for treating hereditary keratinopathies. In this review, we will summarize and discuss recent advances in the preclinical and clinical modelling and development of gene, natural product, pharmacological and protein-based therapies for these disorders, highlighting the feasibility of new approaches for translational clinical therapy.
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Affiliation(s)
- Jean Christopher Chamcheu
- Department of Dermatology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
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Alam H, Sehgal L, Kundu ST, Dalal SN, Vaidya MM. Novel function of keratins 5 and 14 in proliferation and differentiation of stratified epithelial cells. Mol Biol Cell 2011; 22:4068-78. [PMID: 21900500 PMCID: PMC3204069 DOI: 10.1091/mbc.e10-08-0703] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Keratin expression in stratified epithelia is tightly regulated during squamous cell differentiation. Keratins 5 and 14 are expressed in mitotically active basal layer cells, but their function is not well defined. Reported here is the possible role of K14 in regulation of cell proliferation/differentiation in stratified epithelial cells. Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. The complex network of keratin filaments in stratified epithelia is tightly regulated during squamous cell differentiation. Keratin 14 (K14) is expressed in mitotically active basal layer cells, along with its partner keratin 5 (K5), and their expression is down-regulated as cells differentiate. Apart from the cytoprotective functions of K14, very little is known about K14 regulatory functions, since the K14 knockout mice show postnatal lethality. In this study, K14 expression was inhibited using RNA interference in cell lines derived from stratified epithelia to study the K14 functions in epithelial homeostasis. The K14 knockdown clones demonstrated substantial decreases in the levels of the K14 partner K5. These cells showed reduction in cell proliferation and delay in cell cycle progression, along with decreased phosphorylated Akt levels. K14 knockdown cells also exhibited enhanced levels of activated Notch1, involucrin, and K1. In addition, K14 knockdown AW13516 cells showed significant reduction in tumorigenicity. Our results suggest that K5 and K14 may have a role in maintenance of cell proliferation potential in the basal layer of stratified epithelia, modulating phosphatidylinositol 3-kinase/Akt–mediated cell proliferation and/or Notch1-dependent cell differentiation.
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Affiliation(s)
- Hunain Alam
- Advanced Centre for Treatment, Research & Education in Cancer, Tata Memorial Centre, Kharghar, Navi Mumbai 410210, India
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25
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Bowden PE. Gene therapy for keratin genodermatoses: striving forward but obstacles persist. J Invest Dermatol 2011; 131:1403-5. [PMID: 21673708 DOI: 10.1038/jid.2011.121] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
D'Alessandro and colleagues have investigated stress responses in keratinocyte cell lines lacking keratin 14 (K14-null mutation). In this issue, they describe the use of this model to assess the extent of phenotypic rescue achievable by wild-type K14 in the absence of a dominant negative mutation. This work provides proof that, in principle, transfection of wild-type K14 on a null background can significantly normalize the cell and reduce stress responses. However, hurdles to gene therapy in vivo persist because the majority of patients with keratin genodermatoses have heterozygous dominant negative mutations, which are more disruptive than those of the null state. Although correction in the laboratory is now relatively routine, gene delivery to the skin of patients and stable correction of mutations remain major challenges.
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Affiliation(s)
- Paul E Bowden
- Department of Dermatology and Wound Healing, School of Medicine, Cardiff University, Heath Park, Cardiff, UK.
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Chamcheu JC, Navsaria H, Pihl-Lundin I, Liovic M, Vahlquist A, Törmä H. Chemical Chaperones Protect Epidermolysis Bullosa Simplex Keratinocytes from Heat Stress–Induced Keratin Aggregation: Involvement of Heat Shock Proteins and MAP Kinases. J Invest Dermatol 2011; 131:1684-91. [DOI: 10.1038/jid.2011.93] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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D'Alessandro M, Coats SE, Jonkman MF, Jonkmann MF, Leigh IM, Lane EB. Keratin 14-null cells as a model to test the efficacy of gene therapy approaches in epithelial cells. J Invest Dermatol 2011; 131:1412-9. [PMID: 21326298 DOI: 10.1038/jid.2011.19] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Skin fragility disorders caused by keratin mutations are incurable, and a better understanding of their etiology is needed to find new ways to improve and treat these conditions. The best-studied skin fragility disorder is epidermolysis bullosa simplex (EBS), an autosomal dominant condition caused by mutations in keratin 5 (K5) or K14. To analyze disease mechanisms and develop gene therapy strategies, we have used keratinocyte cell lines derived from EBS patients as model systems. Here, we describe two cell lines established from EBS patients with K14-null mutations. We analyze the responses of these cells to stress assays previously shown to discriminate between wild-type and keratin-mutant keratinocytes, to directly evaluate the efficacy of rescuing K14-null cells by supplementation with wild-type K14 complementary DNA (cDNA). The K14-null cells show elevated levels of stress correlating with reduced normal keratin function. By transfecting wild-type K14 into these cells, we demonstrate "proof of principle" that an add-back approach can significantly rescue the normal keratinocyte behavior profile. These K14-null cell lines provide a disease model for studying the effects of keratin ablation in EBS patients and to test the efficacy of gene add-back and other therapy approaches in keratinocytes.
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Affiliation(s)
- Mariella D'Alessandro
- CR UK Cell Structure Research Group, Division of Molecular Medicine, College of Life Sciences, University of Dundee, Dundee, UK.
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Keratin gene mutations in disorders of human skin and its appendages. Arch Biochem Biophys 2010; 508:123-37. [PMID: 21176769 DOI: 10.1016/j.abb.2010.12.019] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 12/16/2010] [Indexed: 11/21/2022]
Abstract
Keratins, the major structural protein of all epithelia are a diverse group of cytoskeletal scaffolding proteins that form intermediate filament networks, providing structural support to keratinocytes that maintain the integrity of the skin. Expression of keratin genes is usually regulated by differentiation of the epidermal cells within the stratifying squamous epithelium. Amongst the 54 known functional keratin genes in humans, about 22 different genes including, the cornea, hair and hair follicle-specific keratins have been implicated in a wide range of hereditary diseases. The exact phenotype of each disease usually reflects the spatial expression level and the types of mutated keratin genes, the location of the mutations and their consequences at sub-cellular levels as well as other epigenetic and/or environmental factors. The identification of specific pathogenic mutations in keratin disorders formed the basis of our understanding that led to re-classification, improved diagnosis with prognostic implications, prenatal testing and genetic counseling in severe keratin genodermatoses. Molecular defects in cutaneous keratin genes encoding for keratin intermediate filaments (KIFs) causes keratinocytes and tissue-specific fragility, accounting for a large number of genetic disorders in human skin and its appendages. These diseases are characterized by keratinocytes fragility (cytolysis), intra-epidermal blistering, hyperkeratosis, and keratin filament aggregation in severely affected tissues. Examples include epidermolysis bullosa simplex (EBS; K5, K14), keratinopathic ichthyosis (KPI; K1, K2, K10) i.e. epidermolytic ichthyosis (EI; K1, K10) and ichthyosis bullosa of Siemens (IBS; K2), pachyonychia congenita (PC; K6a, K6b, K16, K17), epidermolytic palmo-plantar keratoderma (EPPK; K9, (K1)), monilethrix (K81, K83, K86), ectodermal dysplasia (ED; K85) and steatocystoma multiplex. These keratins also have been identified to have roles in apoptosis, cell proliferation, wound healing, tissue polarity and remodeling. This review summarizes and discusses the clinical, ultrastructural, molecular genetics and biochemical characteristics of a broad spectrum of keratin-related genodermatoses, with special clinical emphasis on EBS, EI and PC. We also highlight current and emerging model tools for prognostic future therapies. Hopefully, disease modeling and in-depth understanding of the molecular pathogenesis of the diseases may lead to the development of novel therapies for several hereditary cutaneous diseases.
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Obarzanek-Fojt M, Favre B, Huber M, Ryser S, Moodycliffe A, Wipff PJ, Hinz B, Hohl D. Induction of p38, tumour necrosis factor-α and RANTES by mechanical stretching of keratinocytes expressing mutant keratin 10R156H. Br J Dermatol 2010; 164:125-34. [DOI: 10.1111/j.1365-2133.2010.10013.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wally V, Brunner M, Lettner T, Wagner M, Koller U, Trost A, Murauer EM, Hainzl S, Hintner H, Bauer JW. K14 mRNA reprogramming for dominant epidermolysis bullosa simplex. Hum Mol Genet 2010; 19:4715-25. [DOI: 10.1093/hmg/ddq405] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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Intermediate filaments take the heat as stress proteins. Trends Cell Biol 2010; 20:79-91. [PMID: 20045331 DOI: 10.1016/j.tcb.2009.11.004] [Citation(s) in RCA: 190] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 11/13/2009] [Accepted: 11/17/2009] [Indexed: 11/18/2022]
Abstract
Intermediate filament (IF) proteins and heat shock proteins (HSPs) are large multimember families that share several features, including protein abundance, significant upregulation in response to a variety of stresses, cytoprotective functions, and the phenocopying of several human diseases after IF protein or HSP mutation. We are now coming to understand that these common elements point to IFs as important cellular stress proteins with some roles akin to those already well-characterized for HSPs. Unique functional roles for IFs include protection from mechanical stress, whereas HSPs are characteristically involved in protein folding and as chaperones. Shared IF and HSP cytoprotective roles include inhibition of apoptosis, organelle homeostasis, and scaffolding. In this report, we review data that corroborate the view that IFs function as highly specialized cytoskeletal stress proteins that promote cellular organization and homeostasis.
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