Stabilization of Keratinocyte Monolayer Integrity in the Presence of Anti-Desmoglein-3 Antibodies through FcRn Blockade with Efgartigimod: Novel Treatment Paradigm for Pemphigus?

Pemphigus vulgaris is an autoimmune blistering disease of the epidermis, caused by autoantibodies against desmosomal proteins, mainly desmogleins 1 and 3, which induce an impairment of desmosomal adhesion and blister formation. Recent findings have shown that inhibition of immunoglobulin G binding on the neonatal Fc receptor, FcRn, results in reduced autoantibody recycling and shortens their half-life, providing a valid treatment option for PV. We have here analyzed the role of FcRn in human keratinocytes treated with novel, recombinant anti-desmoglein-3 antibodies that induce pathogenic changes in desmosomes, such as loss of monolayer integrity, aberrant desmoglein-3 localization and degradation of desmoglein-3. We show that blocking IgG binding on FcRn by efgartigimod, a recombinant Fc fragment that is undergoing clinical studies for pemphigus, stabilizes the keratinocyte monolayer, whereas the loss of desmoglein-3 is not prevented by efgartigimod. Our data show for the first time that FcRn may play a direct role in the pathogenesis of pemphigus at the level of the autoantibody target cells, the epidermal keratinocytes. Our data also imply that in keratinocytes, FcRn may have functions different from its known function in IgG recycling. Therefore, stabilization of keratinocyte adhesion by FcRn blocking entities may provide a novel treatment paradigm for pemphigus.

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Apoptosis is not required for acantholysis in pemphigus vulgaris

AJP Cell Physiology ◽

10.1152/ajpcell.00161.2008 ◽

2009 ◽

Vol 296 (1) ◽

pp. C162-C172 ◽

Cited By ~ 32

Author(s):

Enno Schmidt ◽

Judith Gutberlet ◽

Daniela Siegmund ◽

Daniela Berg ◽

Harald Wajant ◽

...

Keyword(s):

Caspase 3 ◽

Pemphigus Vulgaris ◽

Human Keratinocytes ◽

Skin Lesions ◽

Terminal Deoxynucleotidyl Transferase ◽

Epidermal Keratinocytes ◽

Death Domain ◽

Human Epidermal Keratinocytes ◽

Desmosomal Cadherins ◽

Normal Human

The autoimmune blistering skin disease pemphigus vulgaris (PV) is caused primarily by autoantibodies against desmosomal cadherins. It was reported that apoptosis can be detected in pemphigus skin lesions and that apoptosis can be induced by PV-IgG in cultured keratinocytes. However, the role of apoptosis in PV pathogenesis is unclear at present. In this study, we provide evidence that apoptosis is not required for acantholysis in PV. In skin lesions from two PV patients, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) positivity, but not cleaved caspase-3, was detected in single keratinocytes in some lesions but was completely absent in other lesions from the same patients. In cultures of human keratinocytes (HaCaT and normal human epidermal keratinocytes), PV-IgG from three different PV patients caused acantholysis, fragmented staining of Dsg 3 staining, and cytokeratin retraction in the absence of nuclear fragmentation, TUNEL positivity, and caspase-3 cleavage and hence in the absence of detectable apoptosis. To further rule out the contribution of apoptotic mechanisms, we used two different approaches that are effective to block apoptosis induced by various stimuli. Inhibition of caspases by z-VAD-fmk as well as overexpression of Fas-associated death domain-like interleukin-1β-converting enzyme (FLICE)-like inhibitory proteins FLIPL and FLIPS to inhibit receptor-mediated apoptosis did not block PV-IgG-induced effects, indicating that apoptosis was not required. Taken together, we conclude that apoptosis is not a prerequisite for skin blistering in PV but may occur secondary to acantholysis.

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Loss of flotillin expression results in weakened desmosomal adhesion and Pemphigus vulgaris-like localisation of desmoglein-3 in human keratinocytes

Scientific Reports ◽

10.1038/srep28820 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 21

Author(s):

Frauke Völlner ◽

Jawahir Ali ◽

Nina Kurrle ◽

Yvonne Exner ◽

Rüdiger Eming ◽

...

Keyword(s):

Pemphigus Vulgaris ◽

Human Keratinocytes ◽

Desmoglein 3

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The desmosomal cadherin Desmoglein-3 regulates YAP and phospho-YAP in keratinocyte responses to mechanical forces

10.1101/827725 ◽

2019 ◽

Author(s):

Jutamas Uttagomol ◽

Usama Sharif Ahmad ◽

Ambreen Rehman ◽

Yunying Huang ◽

Ana C. Laly ◽

...

Keyword(s):

Target Genes ◽

Hippo Pathway ◽

Cyclic Strain ◽

Human Keratinocytes ◽

Mechanical Forces ◽

Force Transmission ◽

Direct Role ◽

The Impact ◽

Desmoglein 3 ◽

E Cadherin

ABSTRACTDesmoglein 3 (Dsg3), plays a crucial role in cell-cell adhesion and tissue integrity. Increasing evidence suggests that Dsg3 acts as a regulator of cellular mechanotransduction, but little is known about its direct role in mechanical force transmission. The present study investigated the impact of cyclic strain and substrate stiffness on Dsg3 expression and its role in mechanotransduction. A direct comparison was made with E-cadherin, a well-characterized mechanosensor, in human keratinocytes. Exposure of oral and skin keratinocytes to equiaxial cyclic strain promoted changes in expression and localization of junction assembly proteins. Knockdown of Dsg3 by siRNA blocked strain-induced junctional remodeling of E-cadherin and Myosin IIa. Importantly, the study demonstrated that Dsg3 regulates the expression and localization of YAP, a mechanosensor and an effector of the Hippo pathway. Furthermore, we showed that Dsg3 forms a complex with phospho-YAP and sequestered it to the plasma membrane, while Dsg3 depletion had an impact on both YAP and phospho-YAP in their response to mechanical forces, increasing the sensitivity of keratinocytes to both strain-or substrate rigidity-induced nuclear relocalization of YAP and phospho-YAP. We showed that PKP1 seemed to be the key in such a complex formation since its silencing resulted in Dsg3 disruption at the junctions with concomitant loss of pYAP in the peripheral cytoplasm. Finally, we demonstrated that this Dsg3/YAP pathway has an influence on the expression of YAP1 target genes as well as cell proliferation in keratinocytes. Together, these findings provide evidence of a novel role for Dsg3 in keratinocyte mechanotransduction.

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Intraperitoneal injection of pemphigus vulgaris-IgG into mouse depletes epidermal keratinocytes of desmoglein 3 associated with generation of acantholysis

Archives of Dermatological Research ◽

10.1007/s00403-007-0754-9 ◽

2007 ◽

Vol 299 (3) ◽

pp. 165-167 ◽

Cited By ~ 16

Author(s):

En Shu ◽

Yukari Yamamoto ◽

Yumi Aoyama ◽

Yasuo Kitajima

Keyword(s):

Intraperitoneal Injection ◽

Pemphigus Vulgaris ◽

Epidermal Keratinocytes ◽

Desmoglein 3

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Alterations of ultrastructure and elemental composition in cultured human epidermal keratinocytes after treatment with nitrofurazone and silver sulfadiazine

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100127803 ◽

1987 ◽

Vol 45 ◽

pp. 676-677

Author(s):

A. R. Crooker ◽

M. C. Myers ◽

T. L. Beard ◽

E. S. Graham

Keyword(s):

Electron Microscopy ◽

Elemental Composition ◽

Pyrolytic Carbon ◽

Human Keratinocytes ◽

Silver Sulfadiazine ◽

Epidermal Keratinocytes ◽

Human Epidermal Keratinocytes ◽

Culture Systems ◽

Cytotoxicity Endpoints

Cell culture systems have become increasingly popular as a means of screening toxic agents and studying toxic mechanisms of drugs and other chemicals at the cellular and subcellular levels. These in vitro tests can be conducted rapidly in a broad range of relevant mammalian culture systems; a variety of biological and biochemical cytotoxicity endpoints can be examined. The following study utilized human keratinocytes to evaluate the relative cytotoxicities of nitrofurazone (NF) and silver sulfadiazine (SS), the active ingredients of FURACIN(R) Topical Cream and SILVADENE(R) Cream, respectively. These compounds are anti-infectives used in the treatment of burn patients. Cell ultrastructure and elemental composition were utilized as cytotoxicity endpoints.Normal Human Epidermal Keratinocytes (HK) were prepared from the EpiPackTM culture system (Clonetics Corporation, Boulder, CO). For scanning electron microscopy (SEM) and transmission electron microscopy (TEM), cells were seeded on sterile 35 mm Falcon plastic dishes; for elemental microanalysis, cells were plated on polished pyrolytic carbon discs (E. Fullam, Latham, NY) placed in the culture dishes.

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Antioxidant and Pro-Oxidant Capacities as Mechanisms of Photoprotection of Olive Polyphenols on UVA-Damaged Human Keratinocytes

Molecules ◽

10.3390/molecules26082153 ◽

2021 ◽

Vol 26 (8) ◽

pp. 2153

Author(s):

Raffaella Marina Lecci ◽

Isabella D’Antuono ◽

Angela Cardinali ◽

Antonella Garbetta ◽

Vito Linsalata ◽

...

Keyword(s):

Antioxidant Activities ◽

Biological Activities ◽

Human Keratinocytes ◽

Ldl Oxidation ◽

Trolox Equivalent Antioxidant Capacity ◽

Epidermal Keratinocytes ◽

Olive Cultivar ◽

Human Epidermal Keratinocytes ◽

Apoptotic Effect

A wide variety of polyphenols are reported to have considerable antioxidant and skin photoprotective effects, although the mechanisms of action are not fully known. Environmentally friendly and inexpensive sources of natural bioactive compounds, such as olive mill wastewater (OMWW), the by-product of olive-oil processing, can be considered an economic source of bioactive polyphenols, with a range of biological activities, useful as chemotherapeutic or cosmeceutical agents. Green strategies, such as the process based on membrane technologies, allow to recover active polyphenols from this complex matrix. This study aims to evaluate the antioxidant, pro-oxidant, and photoprotective effects, including the underlying action mechanism(s), of the ultra-filtered (UF) OMWW fractions, in order to substantiate their use as natural cosmeceutical ingredient. Six chemically characterized UF-OMWW fractions, from Italian and Greek olive cultivar processing, were investigated for their antioxidant activities, measured by Trolox Equivalent Antioxidant Capacity (TEAC), LDL oxidation inhibition, and ROS-quenching ability in UVA-irradiated HEKa (Human Epidermal Keratinocytes adult) cultures. The photoprotective properties of UF-OMWW were assayed as a pro-oxidant-mediated pro-apoptotic effect on the UVA-damaged HEKa cells, which can be potentially involved in the carcinogenesis process. All the UF-OMWW fractions exerted an effective antioxidant activity in vitro and in cells when administered together with UV-radiation on HEKa. A pro-oxidative and pro-apoptotic effect on the UVA-damaged HEKa cells were observed, suggesting some protective actions of polyphenol fraction on keratinocyte cell cultures.

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Role of CXC chemokine receptor type 4 as a lactoferrin receptor

Biochemistry and Cell Biology ◽

10.1139/bcb-2016-0039 ◽

2017 ◽

Vol 95 (1) ◽

pp. 57-63 ◽

Cited By ~ 11

Author(s):

Yoshiharu Takayama ◽

Reiji Aoki ◽

Ryo Uchida ◽

Atsushi Tajima ◽

Ayako Aoki-Yoshida

Keyword(s):

Biological Activities ◽

Ldl Receptor ◽

Neutralizing Antibody ◽

Human Keratinocytes ◽

Akt Signaling ◽

Target Cells ◽

Bovine Lactoferrin ◽

Lactoferrin Receptor ◽

Stromal Cell Derived Factor ◽

The Many

Lactoferrin exerts its biological activities by interacting with receptors on target cells, including LDL receptor-related protein-1 (LRP-1/CD91), intelectin-1 (omentin-1), and Toll-like receptor 4 (TLR4). However, the effects mediated by these receptors are not sufficient to fully explain the many functions of lactoferrin. C-X-C-motif cytokine receptor 4 (CXCR4) is a ubiquitously expressed G-protein coupled receptor for stromal cell-derived factor-1 (SDF-1/CXCL12). Lactoferrin was found to be as capable as SDF-1 in blocking infection by an HIV variant that uses CXCR4 as a co-receptor (X4-tropic HIV), suggesting that lactoferrin interacts with CXCR4. We addressed whether CXCR4 acts as a lactoferrin receptor using HaCaT human keratinocytes and Caco-2 human intestinal cells. We found that bovine lactoferrin interacted with CXCR4-containing lipoparticles, and that this interaction was not antagonized by SDF-1. In addition, activation of Akt in response to lactoferrin was abrogated by AMD3100, a small molecule inhibitor of CXCR4, or by a CXCR4-neutralizing antibody, suggesting that CXCR4 functions as a lactoferrin receptor able to mediate activation of the PI3K–Akt signaling pathway. Lactoferrin stimulation mimicked many aspects of SDF-1-induced CXCR4 activity, including receptor dimerization, tyrosine phosphorylation, and ubiquitination. Cycloheximide chase assays indicated that turnover of CXCR4 was accelerated in response to lactoferrin. These results indicate that CXCR4 is a potent lactoferrin receptor that mediates lactoferrin-induced activation of Akt signaling.

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A Central Role for the Armadillo Protein Plakoglobin in the Autoimmune Disease Pemphigus Vulgaris

The Journal of Cell Biology ◽

10.1083/jcb.153.4.823 ◽

2001 ◽

Vol 153 (4) ◽

pp. 823-834 ◽

Cited By ~ 130

Author(s):

Reto Caldelari ◽

Alain de Bruin ◽

Dominique Baumann ◽

Maja M. Suter ◽

Christiane Bierkamp ◽

...

Keyword(s):

Steric Hindrance ◽

In Vitro Model ◽

Molecular Mechanisms ◽

Pemphigus Vulgaris ◽

Cell Types ◽

Linear Distribution ◽

Igg Binding ◽

Vitro Model ◽

First Time

In pemphigus vulgaris (PV), autoantibody binding to desmoglein (Dsg) 3 induces loss of intercellular adhesion in skin and mucous membranes. Two hypotheses are currently favored to explain the underlying molecular mechanisms: (a) disruption of adhesion through steric hindrance, and (b) interference of desmosomal cadherin-bound antibody with intracellular events, which we speculated to involve plakoglobin. To investigate the second hypothesis we established keratinocyte cultures from plakoglobin knockout (PG−/−) embryos and PG+/+ control mice. Although both cell types exhibited desmosomal cadherin-mediated adhesion during calcium-induced differentiation and bound PV immunoglobin (IgG) at their cell surface, only PG+/+ keratinocytes responded with keratin retraction and loss of adhesion. When full-length plakoglobin was reintroduced into PG−/− cells, responsiveness to PV IgG was restored. Moreover, in these cells like in PG+/+ keratinocytes, PV IgG binding severely affected the linear distribution of plakoglobin at the plasma membrane. Taken together, the establishment of an in vitro model using PG+/+ and PG−/− keratinocytes allowed us (a) to exclude the steric hindrance only hypothesis, and (b) to demonstrate for the first time that plakoglobin plays a central role in PV, a finding that will provide a novel direction for investigations of the molecular mechanisms leading to PV, and on the function of plakoglobin in differentiating keratinocytes.

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