Desmoglein Research Articles

Optimizing Pemphigus Management With Rituximab and Short-Term Relapse Predictors

Rituximab is approved for the treatment of moderate to severe pemphigus. However, 20% of patients in the RITUX 3 trial relapsed within the first year of treatment. To assess the outcome of an additional rituximab infusion at month 6 in patients with pemphigus who were in complete remission (CR) after rituximab regimen but had 1 or more predictors of relapse at month 3. This multicenter cohort study was conducted in France from September 2018 to June 2023 to assess patients with newly diagnosed pemphigus who were in CR after treatment with the RITUX 3 regimen but had predictors of relapse at month 3. Relapse factors were a Pemphigus Disease Area Index (PDAI) score of 45 or higher, desmoglein 1 (DSG1) antibodies greater than 20 IU/mL, and/or DSG3 antibodies greater than 130 IU/mL. Patients in CR at month 6 with at least 1 predictor of relapse were treated with an additional rituximab infusion at month 6. Primary end point was the rate of CR without corticosteroid therapy for 2 months at month 12. Secondary end points were the rate of relapse, number of patients needing to be re-treated (NNT) with rituximab to avoid a relapse, and safety. The study population comprised 87 patients (44 females [50.6%] and 43 [49.4%] males), with a mean (SD [range]) age of 55.3 (15.2 [24-92]) years at pemphigus diagnosis. Of these, 64 patients (73.6%) had pemphigus vulgaris and 23 (26.4%) had pemphigus foliaceus. At month 6, CR had been achieved by 77 patients (88.5%), and 10 (11.5%) had persistent disease activity. Of the 77 patients in CR, 30 (39.0%) had at least 1 predictor of relapse and received an additional infusion of rituximab; 47 patients (61.0%) without a predictor did not. Two patients without a predictor and no patients with a predictor experienced relapse-an overall relapse rate of 2.6% and an NNT of 3.6 (95% CI, 1.6-46.5). The 10 patients (11.5%) with persistent disease activity at month 6 were re-treated with rituximab, 1000 mg. At month 12, the rate of CR without corticosteroid therapy for a minimum of 2 months was 72 of 77 (93.5%) among patients who had achieved CR at month 6, and 72 of 87 (82.7%) for the whole study population. Eight serious adverse effects were reported among 5 patients; there were no deaths. This multicenter cohort study indicates that using predictors such as baseline PDAI score, anti-DSG1 antibodies, and/or anti-DSG3 antibodies to initiate preemptive treatment with additional rituximab may reduce the rate of short-term relapse.

Coexistence of T‐Cell Lymphoblastic Lymphoma and Ichthyosis Vulgaris: A Case Report

Ichthyosis vulgaris (IV) is an inherited disorder characterized by the scaling of the skin. It is caused by mutations in the filaggrin gene. IV is a reactive skin manifestation that may be associated with malignant hematological disease. Its association with neoplastic diseases such as Hodgkin lymphoma, anaplastic large‐cell lymphoma, and mycosis fungoides has been reported. T‐cell non‐Hodgkin lymphoma (T‐NHL) with ichthyosis has been rarely reported in the literature. Here, we report a case of T‐cell lymphoma with congenital IV caused by a desmoglein 1 (DSG1) gene mutation associated with hyper‐IgE syndrome (HIES). A 7‐year‐old male patient with a diagnosis of congenital IV had a biopsy performed at an external center due to multiple lymphadenopathies, which revealed T‐cell lymphoblastic lymphoma. A homozygous variant in the DSG1 gene was detected through whole‐exome sequencing. The diagnosis of HIES was confirmed through clinical evaluation, including elevated serum IgE levels and associated symptoms. Skin findings, growth retardation, and HIES overlap with Online Mendelian Inheritance in Man (OMIM) #615508, and parental carrier status was confirmed. The association between ichthyosis and lymphoma was determined based on the presence of lymphoma in a patient with congenital ichthyosis and the identification of a genetic mutation in DSG1. In conclusion, the coexistence of lymphoma and IV is rare. The mechanisms of their formation are different, and they can occur independently. Rare genetic syndromes or inherited diseases can cause different health problems, such as lymphoma and ichthyosis, to occur together.

The transmembrane domain of the desmosomal cadherin desmoglein-1 governs lipid raft association to promote desmosome adhesive strength.

Cholesterol- and sphingolipid-enriched domains called lipid rafts are hypothesized to selectively coordinate protein complex assembly within the plasma membrane to regulate cellular functions. Desmosomes are mechanically resilient adhesive junctions that associate with lipid raft membrane domains, yet the mechanisms directing raft association of the desmosomal proteins, particularly the transmembrane desmosomal cadherins, are poorly understood. We identified the desmoglein-1 (DSG1) transmembrane domain (TMD) as a key determinant of desmoglein lipid raft association and designed a panel of DSG1TMD variants to assess the contribution of TMD physicochemical properties (length, bulkiness, and palmitoylation) to DSG1 lipid raft association. Sucrose gradient fractionations revealed that TMD length and bulkiness, but not palmitoylation, govern DSG1 lipid raft association. Further, DSG1 raft association determines plakoglobin recruitment to raft domains. Super-resolution imaging and functional assays uncovered a strong relationship between the efficiency of DSG1TMD lipid raft association and the formation of morphologically and functionally robust desmosomes. Lipid raft association regulated both desmosome assembly dynamics and DSG1 cell surface stability, indicating that DSG1 lipid raft association is required for both desmosome formation and maintenance. These studies identify the biophysical properties of desmoglein transmembrane domains as key determinants of lipid raft association and desmosome adhesive function.

Striate palmoplantar keratoderma: a novel DSG1 mutation, combined with an LDLR mutation.

Palmoplantar keratoderma (PPK) is a heterogeneous group of disorders characterized by abnormal thickening of the skin on the palms and soles. Striate palmoplantar keratoderma (SPPK) is commonly caused by heterozygous mutations in the desmoglein-1 (DSG1) gene. This study aimed to report a case of a 36-year-old Chinese female patient with SPPK caused by a novel DSG1 gene mutation, along with her family history, and explore its potential relationship with other genetic variants. Whole-exome sequencing was performed on the patient and their family members to identify the pathogenic mutation, which was validated by Sanger sequencing. Histological and electron microscopy analyses were conducted to examine the pathological characteristics of skin tissue.of skin tissue. A frameshift mutation, c.1285del, in exon 10 of the DSG1 gene was identified, leading to a loss of protein function and resulting in SPPK. This mutation was also detected in two other family members with similar phenotypes. Additionally, a classical splicing variant, c.313+2dup, in the low-density lipoprotein receptor (LDLR) gene associated with hypercholesterolemia was identified in the patient; however, no direct association with SPPK was observed. This study was the first to report a novel mutation in the DSG1 gene associated with SPPK and suggested a potential role of the LDLR gene variant in SPPK patients, providing new insights for further research into the genetic mechanisms underlying SPPK.

Success of Immunopathogenetic Therapy for Management of Congenital Ichthyosis, Combined Form, in a Child: Rare Clinical Case

Background. Congenital ichthyosis (CI) is relating to the group of clinical and genetically heterogeneous severe genodermatoses. SAM syndrome is included in classification of CI syndromic forms. Defects in the desmoplakin (DSP) and desmoglein 1 (DSG1) genes are the prime cause of disease. Impaired function of encoded proteins leads to desmosomal anomalies and disease symptoms. Comorbid atopic syndrome becomes the major cause of diagnostic mistakes. Patients are observed continuously with diagnosis “Atopic dermatitis (AD) torpid to standard treatment methods”. Clinical case description. This article describes a rare case of a boy with severe AD. Despite the chronic dermatosis several systemic disorders were revealed during examination: short stature, protein-energy malnutrition, adrenal insufficiency, juvenile polyarthritis, vitamin D deficiency, onychodystrophy, dysmorphic disorders. Molecular genetic study conducted via high-throughput sequencing followed by validation with Sanger sequencing has revealed two genetic variants: novel variant chr18:28934543G>T in the DSG1 gene in the heterozygous state and pathogenic variant chr5:157468728C>A in the NIPAL4 gene in the homozygous state. As a result, the final diagnosis was established: “SAM syndrome. Congenital ichthyosiform erythroderma”. Flow cytometry immunology study has shown dominant immunological profile of Th17-, and Thact-lymphocyte proliferation. The immunobiological therapy with IL-17A inhibitor, secukinumab, was initiated. Clinical efficacy was evaluated via ISS (Ichthyosis Severity Index), CDLQI (Children’s Dermatology Life Quality Index), pruritus numerical rating scale. ISS was 5.8 points, pruritus scale — 9, CDLQI — 24 at therapy initiation. Improvement in the skin condition was observed after a month of therapy. ISS was 1.2 points, pruritus scale — 2, CDLQI — 4 6 months after the therapy initiation. Conclusion. The diagnosis of a child with combined form of CI made it possible to change the management strategy, to prescribe pathogenetically justified targeted immunobiological therapy, and to achieve significant improvement in the child's health and quality of life, which does not differ from healthy peers.

Abstract Mo046: GJA1-20k Restores Connexin-43 Trafficking and β-Catenin Signaling in Myocytes Lacking Desmoplakin

Background: Arrhythmogenic Cardiomyopathy (ACM) is an insidious hereditary heart disease that results in structural and electrical cardiac abnormalities leading to arrhythmogenesis and heart failure. ACM is characterized by cardiomyocyte loss, decreased cellular coupling, and fibrofatty replacement. The disease arises from mutations in desmosomal genes, such as plakophilin (PKP), desmoglein (DSG), and desmoplakin (DSP). The pathogenesis of this disease is linked to dysfunction at the level of several cellular processes and pathways, including Wnt/β-catenin signaling. Recent evidence has shown that GJA1-20k, a truncated isoform of Connexin-43 (Cx43) generated by internal translation, has a therapeutic role in preserving Cx43 trafficking and cell-cell coupling in ACM of DSG origin. This study aims to investigate the role of GJA1-20k in protecting against ACM of DSP origin by evaluating its effect in cell models on Cx43 trafficking and Wnt/β-catenin signaling. Methods: DSP knockdown was performed on HEK cells and mouse neonatal cardiomyocytes. The role of GJA1-20k was determined using imaging, biochemical, and molecular biology techniques. Results: Protein levels of Cx43 and β-catenin were decreased on Western blot (WB) upon DSP knockdown. These findings were corroborated through imaging wherein the signal intensity for Cx43 at cellular junctions and β-catenin at the membrane was significantly decreased compared to the control group. β-catenin signal intensity was also decreased within the nucleus. Upon administration of GJA1-20k, protein levels of Cx43 were normalized on WB. Moreover, the ratio of phosphorylated β-catenin (inactive) to total β-catenin was decreased. Imaging studies identified a significant increase in Cx43 and β-catenin at the membrane in ACM models treated with GJA1-20k. This was also accompanied by an increase in β-catenin signal intensity within the nucleus. A TOP-flash luciferase assay was performed and revealed a significant increase in β-catenin transcriptional activity in the presence of GJA1-20k despite DSP knockdown. Conclusions: These results suggest that GJA1-20k is able to rescue Cx43 trafficking and recover Wnt/β-catenin signaling in cells and cardiomyocytes lacking DSP. The ability of GJA1-20k to restore dysfunctional genetic pathways involved in arrhythmogenesis and fibro-adipogenesis make it an attractive potential candidate for targeted therapy against ACM.

The production of CXCL13 in CD4+ T cells is influenced by adjacent Tregs in the tertiary lymphoid structures of chronic pemphigus blisters

Abstract Pemphigus is a rare and life-threatening autoimmune blistering disease mediated by autoreactive B cells targeting desmogleins (DSGs) in keratinocytes. Anti-DSG autoantibodies disrupt cell-cell adhesion, leading to suprabasal acantholytic blisters. Our investigation reveals the presence of tertiary lymphoid structures (TLSs) harboring DSG-specific B cells and plasma cells in chronic skin blisters of pemphigus. TLSs, resembling B-cell follicles of secondary lymphoid organs, are detected in various inflammatory diseases. CXCL13 is an important chemokine for recruiting CXCR5-expressing naïve B and T follicular helper cells. Through immunofluorescence studies, we found that CXCL13+ cells were mainly produced by CD4+ T cells. Single-cell RNA sequencing revealed clonally expanded CXCL13+CD4+ T cells containing DSG3-specific memory T cells with activated cytotoxic features. Paradoxically, these cells exhibit an attenuation of T-cell receptor (TCR) signaling when expressing high levels of CXCL13. Spatial proteomics reveals that Tregs are spatially adjacent to CXCL13+CD4+ T cells within the skin TLSs. In vitro depletion of Tregs leads to decreased CXCL13 production by CD4+ T cells. These data suggest that adjacent Tregs play a role in regulating CXCL13+CD4+ T cells. In conclusion, skin TLSs are associated with the maintenance of chronic blisters, and the microenvironmental network involving CXCL13+CD4+ T cells and Tregs plays a crucial role in CXCL13 production.

EGFR Inhibition by Erlotinib Rescues Desmosome Ultrastructure and Keratin Anchorage and Protects against Pemphigus Vulgaris IgG–Induced Acantholysis in Human Epidermis

Pemphigus is a severe blistering disease caused by autoantibodies primarily against the desmosomal cadherins desmoglein (DSG)1 and DSG3 which impair desmosome integrity. Especially for the acute phase, additional treatment options allowing to reduce corticosteroids would fulfill an unmet medical need. Here, we provide evidence that epidermal growth factor receptor (EGFR) inhibition by erlotinib ameliorates pemphigus vulgaris immunoglobulin G (PV-IgG) -induced acantholysis in intact human epidermis. PV-IgG caused phosphorylation of EGFR (Y845) and SRC in human epidermis. In line with that, a phosphotyrosine kinome analysis revealed a robust response associated with EGFR and SRC family kinase signaling in response to PV-IgG but not pemphigus foliaceus autoantibodies. Erlotinib inhibited PV-IgG-induced epidermal blistering and EGFR phosphorylation, loss of desmosomes as well as ultrastructural alterations of desmosome size, plaque symmetry, keratin filament insertion and restored the desmosome midline considered as hallmark of mature desmosomes. Erlotinib enhanced both single molecule DSG3 binding frequency and strength and delayed DSG3 fluorescence recovery supporting that EGFR inhibition increases DSG3 availability and cytoskeletal anchorage. Our data indicate that EGFR is a promising target for pemphigus therapy due to its link to several signaling pathways known to be involved in pemphigus pathogenesis.

Calcified Cartilage-Guided Identification of Osteogenic Molecules and Geometries.

Calcified cartilage digested by chondroclasts provides an excellent scaffold to initiate bone formation. We analyzed bioactive proteins and microarchitecture of calcified cartilage either separately or in combination and evaluated biomimetic osteogenic culture conditions of surface-coated micropatterning. To do so, we prepared a crude extract from porcine femoral growth plates, which enhanced in vitro mineralization when coated on flat-bottom culture dishes, and identified four candidate proteins by fractionation and mass spectrometry. Murine homologues of two candidates, desmoglein 4 (DSG4) and peroxiredoxin 6 (PRDX6), significantly promoted osteogenic activity based on in vitro mineralization and osteoblast differentiation. Moreover, we observed DSG4 and PRDX6 protein expression in mouse femur. In addition, we designed circular, triangular, and honeycomb micropatterns with 30 or 50 μm units, either isolated or connected, to mimic hypertrophic chondrocyte-sized compartments. Isolated, larger honeycomb patterns particularly enhanced osteogenesis in vitro. Mineralization on micropatterns was positively correlated with the reduction of osteoblast migration distance in live cell imaging. Finally, we evaluated possible combinatorial effects of coat proteins and micropatterns and observed an additive effect of DSG4 or PRDX6 coating with micropatterns. These data suggest that combining a bioactive surface coating with osteogenic micropatterns may recapitulate initiation of bone formation during endochondral ossification.

Diagnosis and treatment of arrhythmogenic cardiomyopathy in children

Objective: To summarize the clinical manifestations, experiences in diagnosis and treatment of arrhythmogenic cardiomyopathy (ACM) in children. Methods: A retrospective analysis of the clinical manifestations, laboratory tests, radiological features, treatment and follow-up results was conducted in 11 children diagnosed with ACM at the center of congenital heart disease, Beijing anzhen hospital from May 2010 to March 2022. Results: A total of 11 patients aged 2 to 16 years, including 5 males and 6 females were diagnosed with ACM. The clinical manifestations included decreased activity tolerance (7 patients), heart failure (4 patients), syncope or sudden death (3 patients), palpitation (3 patients), and chest tightness and pain (3 patients). Electrocardiogram showed right bundle branch block in 9 cases, paroxysmal ventricular tachycardia in 4 cases, frequent premature ventricular contraction in 4 cases, ventricular pre-excitation in 1 case, left bundle branch block in 1 case, and first degree atrioventricular block in 2 cases. Echocardiography showed enlargement of the right heart, widening of the right ventricular outflow tract, and thinning and bulging of the local wall of the right ventricle with reduced pulsation. Ventricular thrombosis was found in 2 cases. Six children underwent cardiac magnetic resonance imaging, which mainly showed severe enlargement of the right heart, thin free wall of the right ventricle, decreased right heart function, enhanced right ventricular myocardium, and formation of right ventricular aneurysm. Two children underwent myocardial biopsy examination and presented with typical pathological changes of ACM. Genetic tests in five patients revealed DSG2 gene mutation in 2 cases, PKP2 gene mutation in 2 cases, and MYH6 gene mutation in 1 case. All patients received anti heart failure treatment and antiarrhythmic drugs. Two children received anticoagulant treatment due to ventricular thrombosis. Radiofrequency ablation was performed in 2 patients. Glenn procedure was performed in 4 patients, and heart transplantation was performed in 1 patient due to progressive heart failure. The follow-up period ranged from 6 months to 12 years. Two cases died of right heart failure, 6 cases had different degrees of heart failure, 1 case had intermittent chest tightness and pain, and 2 cases were stable. Conclusions: ACM is a progressive genetic cardiomyopathy characterized by decreased activity tolerance, cardiac failure and arrhythmia in pediatric patients. The diagnosis is mainly based on clinical manifestations, electrocardiogram, cardiac imaging changes, and genetic testing. Early detection, diagnosis, and personalized treatment can improve the prognosis.

Abstract 4009: Discovery of inhibitory CAR target DSG1 for damping NECTIN4 on-target off-tumor toxicity in iPSC-derived CAR-T cell therapy

Abstract Century Therapeutics is developing NECTIN4 targeted induced Pluripotent Stem Cell (iPSC) derived Chimeric Antigen Receptor (CAR) T cell therapy. NECTIN4 targeted antibody drug conjugate enfortumab vedotin, while generally well tolerated, causes severe skin adverse events in some patients, thought to be driven by on-target off-tumor toxicity against NECTIN4 displaying skin keratinocytes. We include a safety switch in our first clinical-stage iPSC-derived CAR-NK cell therapy, CNTY-101, which provides an antibody target for elimination of the engineered cells should that be necessary. An additional method for reducing the incidence and severity of this type of adverse event is through the incorporation of an inhibitory CAR, also known as a NOT-gate, directed against antigen expressed on normal skin keratinocytes, but the optimal surface protein to target with such an inhibitory CAR for a NECTIN4 targeted therapy is unknown. Here, we identify DSG1 (Desmoglein-1) as a top inhibitory CAR target for NECTIN4 targeted CAR-T cell therapy by conducting a multi-omics analysis of public single-cell RNAseq, bulk RNAseq, and protein microarray immunohistochemistry datasets. We find that DSG1 is constitutively and uniformly displayed on the surface of skin keratinocytes in the layers of epidermis where they display NECTIN4, and DSG1 gene expression in normal skin is uniformly high across individuals. Conversely, DSG1 mRNA and protein are rarely expressed in NECTIN4 expressing cancer indications including bladder, breast, non-small cell lung, ovarian, and pancreatic. Further, autoimmune antibodies specific to DSG1 have been described, suggesting that DSG1 is targetable by a CAR in situ. Finally, DSG1 is not expressed by our iPSC-derived CAR-T cells. While NECTIN4 expression is greatest in skin keratinocytes, epithelial cells in other tissues express NECTIN4 at lower levels. In this study, we compare the expression levels of NECTIN4 to targets associated with tissue and cell-type specific on-target off-tumor toxicity in primary CAR-T cell clinical trials. Our findings support the strategy of DSG1-directed inhibitory CAR incorporation into NECTIN4 specific CAR-T cell therapeutic candidates. Citation Format: Matthew S. Hall, Christopher M. Dower, Michael Miller, John Wheeler, Jill Carton, Ohad Manor, Hyam Levitsky. Discovery of inhibitory CAR target DSG1 for damping NECTIN4 on-target off-tumor toxicity in iPSC-derived CAR-T cell therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4009.

A Retrospective View of the Triple-Negative Breast Cancer Microenvironment: Novel Markers, Interactions, and Mechanisms of Tumor-Associated Components Using Public Single-Cell RNA-Seq Datasets.

Triple-negative breast cancer (TNBC) is a significant clinical challenge due to its aggressive nature and limited treatment options. In search of new treatment targets, not only single genes but also gene pairs involved in protein interactions, we explored the tumor microenvironment (TME) of TNBC from a retrospective point of view, using public single-cell RNA sequencing datasets. A High-resolution Cell type Annotation Tool, HiCAT, was used first to identify the cell type in 3-level taxonomies. Tumor cells were then identified based on the estimates of copy number variation. With the annotation results, differentially expressed genes were analyzed to find subtype-specific markers for each cell type, including tumor cells, fibroblast, and macrophage. Cell-cell interactions were also inferred for each cell type pair. Through integrative analysis, we could find unique TNBC markers not only for tumor cells but also for various TME components, including fibroblasts and macrophages. Specifically, twelve marker genes, including DSC2 and CDKN2A, were identified for TNBC tumor cells. Another key finding of our study was the interaction between the DSC2 and DSG2 genes among TNBC tumor cells, suggesting that they are more tightly aggregated with each other than those of other subtypes, including normal epithelial cells. The overexpression of DSC2 in TNBC and its prognostic power were verified by using METABRIC, a large bulk RNA-seq dataset with clinical information. These findings not only corroborate previous hypotheses but also lay the foundation for a new structural understanding of TNBC, as revealed through our single-cell analysis workflow.

The Need of Differential Diagnosis Between Vulvar Lichen Sclerosus and Autoimmune Dermatoses in Adolescent Girls.

Vulvar lichen sclerosus (VLS) is a chronic inflammatory condition affecting the anogenital region, which can manifest in prepubertal or adolescent patients. The prevailing theories point to autoimmune and genetic factors. The primary symptoms of VLS typically include vulvar itching, discomfort, dysuria, and constipation. Physical examination often reveals a characteristic figure8 pattern, involving the labia minora, clitoral hood, and perianal region. However, these symptoms and the age of onset are nonspecific and require differentiation from autoimmune dermatoses such as bullous diseases, pemphigus diseases, epidermolysis bullosa acquisita, and dermatitis herpetiformis. We performed this study to distinguish VLS from autoimmune dermatoses, and in doing so, uncover the underlying causes of chronic vulvar changes. This knowledge will enable healthcare providers to offer appropriate medical care to affected patients. The study was conducted between July 2020 and February 2021, with a sample of 55 girls aged 2-18years who did not have any systemic diseases. The study group was composed of 20 girls previously diagnosed with vulvar lichen sclerosus, while the control group included 35 girls without VLS. Questionnaires regarding the medical history of the children were completed by their legal guardians. Blood samples were collected and analyzed biochemically to assess human immunoglobulin A (IgA), IgG, and IgM antibodies against various substrates, including the desmosome of stratum spinosum, basement membrane zone, desmoglein 1 (DSG1), desmoglein 3 (DSG3), BP180-NC16A-4X, BP230gC, pemphigoid antigen, collagen type VII NC1, transitional epithelium, gliadin (GAF-3X), endomysium (EMA), and cellular nucleus (ANA). The analysis of the study group revealed that the most commonly observed signs and symptoms included: itching, soreness, burning sensations, and excoriation, as well as erythema or/and pallor of the skin and perineal mucosa. Among the assessed antibodies, only anti-GAF3x antibodies and ANA antibodies were detected. However, the results did not reach statistical significance (p > 0.5).

Ser194Leu DSG2 mutation, associated with arrhythmogenic left ventricular cardiomyopathy and ventricular tachycardia.

Arrhythmogenic cardiomyopathy (AC) is an inherited cardiomyopathy characterized by fibro-fatty replacement of cardiomyocytes, leading to life-threatening ventricular arrhythmia and heart failure. Pathogenic variants of desmoglein2 gene (DSG2) have been reported as genetic etiologies of AC. In contrast, many reported DSG2 variants are benign or variants of uncertain significance. Correct genetic variant classification is crucial for determining the best medical therapy for the patient and family members. Pathogenicity of the DSG2 Ser194Leu variant that was identified by whole exome sequencing in a patient, who presented with ventricular tachycardia and was diagnosed with AC, was investigated by electron microscopy and immunohistochemical staining of endomyocardial biopsy sample. Electron microscopy demonstrated a widened gap in the adhering junction and a less well-organized intercalated disk region in the mutated cardiomyocytes compared to the control. Immunohistochemical staining in the proband diagnosed with AC showed reduced expression of desmoglein 2 and connexin 43 and intercalated disc distortion. Reduced expression of DSG2 and Connexin 43 were observed in cellular cytoplasm and gap junctions. Additionally, we detected perinuclear accumulation of DSG2 and Connexin 43 in the proband sample. Ser194Leu is a missense pathogenic mutation of DSG2 gene associated with arrhythmogenic left ventricular cardiomyopathy.

Rituximab in the Management of Autoimmune Bullous Diseases: A Treatment-Resistant Case Series from a Single Central European Referral Center.

Background and Objectives: Rituximab (RTX) has been the predominant treatment for autoimmune bullous diseases (AIBDs). The objective of this research was to assess the advantages and safety characteristics of RTX treatment in individuals with AIBD. This assessment focused on clinical remission and a reduction in glucocorticosteroid usage, its effect on the titers of autoantibodies targeting desmoglein-1 (DSG-1) and desmoglein-3 (DSG-3), and adverse occurrences during a 12-month follow-up period in a dermatology department within a Central European university context. Materials and Methods: Our case series involved eleven patients, including eight patients with pemphigus vulgaris, two with pemphigus foliaceus, and one with epidermolysis bullosa acquisita. They received a 1 g dose of rituximab, repeated over a two-week interval. Results: The reduction in a prednisone-equivalent dosage after 2, 6, and 12 months following the second RTX infusion was 65.05%, 73.99%, and 76.93%, in that order. The titers of antibodies against DSG-1 exhibited reductions of 43.29%, 75.86%, and 54.02% at 2, 6, and 12 months, respectively. By contrast, the antibody concentrations targeting DSG-3 displayed a decrease of 27.88%, 14.48%, and 5.09% at the corresponding time points. Over the course of the 12-month monitoring period, 18.18% of patients experienced disease relapse, while the remaining individuals achieved either complete or partial remission with minimal or no therapy. Adverse effects were noted in 36.36% of the patient population; they were mild, and no serious adverse effects were reported. Conclusions: RTX represents an efficacious and well-tolerated therapeutic option for the management of AIBD and merits consideration in cases of refractory AIBD. However, further research is imperative to delineate the most optimal dosage, dosing frequency, and total quantity of maintenance infusions required. Additionally, there is a compelling need for studies that explore the impact of RTX on individuals with AIBD who do not exhibit a significant reduction in anti-desmoglein autoantibody levels.

JNK inhibition enhances cell-cell adhesion impaired by desmoglein3 gene disruption in keratinocytes.

c-Jun NH2-terminal protein kinase (JNK) and p38 are stress-activated mitogen-activated protein kinases (MAPK) that are phosphorylated by various stimuli. It has been reported that the loss of desmoglein (DSG) 3, a desmosomal transmembrane core molecule, in keratinocytes impairs cell-cell adhesion accompanied by p38 MAPK activation. To understand the biological role of DSG3 in desmosomes and its relationship with stress-activated MAPKs, we established DSG3 knockout keratinocytes (KO cells). Wild-type cells showed a linear localization of DSG1 to cell-cell contacts, whereas KO cells showed a remarkable reduction despite the increased protein levels of DSG1. Cell-cell adhesion in KO cells was impaired over time, as demonstrated by dispase-based dissociation assays. The linear localization of DSG1 to cell-cell contacts and the strength of cell-cell adhesion were promoted by the pharmacological inhibition of JNK. Conversely, pharmacological activation of JNK, but not p38 MAPK, in wild-type cells reduced the linear localization of DSG1 in cell-cell contacts. Our data indicate that DSG1 and DSG2 in KO cells cannot compensate for the attenuation of cell-cell adhesion strength caused by DSG3 deficiency and that JNK inhibition restores the strength of cell-cell adhesion by increasing the linear localization of DSG1 in cell-cell contacts in KO cells. Inhibition of JNK signaling may improve cell-cell adhesion in diseases in which DSG3 expression is impaired.

Aspirin-exacerbated respiratory disease is associated with variants in filaggrin, epithelial integrity, and cellular interactions

BackgroundPrevious studies identified upto 6% of patients with Aspirin-Exacerbated Respiratory Disease (AERD) have family history of AERD indicating a possible link with genetic polymorphisms. However, whole exome sequencing (WES) studies of such associations are currently lacking. ObjectivesWe sought to examine whether WES can identify pathogenic variants associated with AERD. MethodsAERD diagnosis was confirmed in patients with nasal polyps and asthma. WES was performed using an Illumina sequencing platform. Human Phenotype Ontology (HPO) terms were used to define the patients’ phenotypes. Exomiser was used to annotate, filter, and prioritize possible disease-causing genetic variants. ResultsAmong thirty-nine patients with AERD, 41% reported a family history of asthma and 5% a family history of AERD. Pathogenic exome variants in the filaggrin gene (FLG) were found in two patients (5%). Other variants not known to be pathogenic were detected in an additional 16 patients (41%) in genes related to epithelial integrity and cellular interactions, including genes encoding desmoglein 3 (DSG3), dynein axonemal heavy chain 9 (DNAH9), collagen type VII alpha 1 chain (COL7A1), collagen type XVII alpha 1 chain (COL17A1), chromodomain helicase DNA binding protein-7 (CHD7), TSC complex subunit 2/tuberous sclerosis-2 protein (TSC2), P-selectin (SELP), and platelet-derived growth factor receptor-alpha (PDGFRA). ConclusionWES identified a monogenic susceptibility to AERD in 5% of patients with FLG pathogenic variants. Other variants, not previously identified as pathogenic, were found in genes relevant to epithelial integrity and cellular interactions and may further reveal genetic factors that contribute to this condition.

КЛИНИЧЕСКИЙ СЛУЧАЙ БИВЕНТРИКУЛЯРНОЙ АРИТМОГЕННОЙ КАРДИОМИОПАТИИ, АССОЦИИРОВАННОЙ С МУТАЦИЕЙ В ГЕНЕ DSG2

This article describes clinical observation over a patient with a biventricular form of arrhythmogenic cardiomyopathy associated with a mutation in DSG2 gene. The morphological realization of this mutation is associated with fibrous-fat replacement of the myocardium of both ventricles of the heart, which is clinically manifested by the development of life-threatening ventricular arrhythmias and a high risk of biventricular heart failure with a tendency to a progressive decrease in myocardial contractility. The affect on young people of working age, hereditary determinism and an unfavorable prognosis of survival actualizes the importance of diagnostic alertness in the examination of young patients with a clinical picture including ventricular arrhythmias, presyncope, syncope conditions and sudden cardiac death. The main issues of diagnosis, criteria for diagnosis in accordance with the Padua criteria (2020), current principles of treatment and prevention of sudden cardiac death are considered.

G. vaginalis increases HSV-2 infection by decreasing vaginal barrier integrity and increasing inflammation in vivo.

Clinically, a dysbiotic vaginal microbiota (VMB) colonized with anaerobic species such as Gardnerella vaginalis has been linked to increased susceptibility to viral sexually transmitted infections (STIs) such as Herpes Simplex Virus Type 2 (HSV-2). The mechanism is poorly understood due to the lack of small animal models. Mice were inoculated with 107 CFU of the eubiotic bacteria Lactobacillus crispatus, the dysbiotic bacteria G. vaginalis, or PBS as a negative control every 48 h for ten days. On day ten, mice were inoculated with 105 PFU WT HSV-2 333 and survival, pathology, and viral titers were assessed. To elucidate changes in the vaginal microenvironment following bacterial inoculations, vaginal tissue and washes were collected following ten days of inoculations. To assess barrier integrity, tissue was fixed and stained for the barrier protein Desmoglein-1 (DSG-1). To evaluate the immune microenvironment, tissue was processed for flow cytometry to examine tissue-resident T cells and cytokine production by T cells. Vaginal washes were used for multiplex cytokine/chemokine analysis. G. vaginalis inoculated mice infected with HSV-2 had significantly decreased survival rates, increased pathology, and higher viral titers than PBS and L. crispatus inoculated mice. The vaginal epithelium of G. vaginalis inoculated mice showed decreased DSG-1 staining compared to other groups, indicating compromised barrier function. Decreased total numbers of CD4+ and CD8+ T cells expressing activated mucosal immune markers CD44, CD69, and CD103 were observed in the vaginal tract of G. vaginalis inoculated mice. They also showed increased proportions of T cells expressing inflammatory cytokines TNF-α and IFN-γ, while L. crispatus inoculated mice had increased proportions and absolute counts of T cells expressing the regulatory cytokine IL-10. In the multiplex assay, vaginal washes from G. vaginalis mice had increased inflammatory cytokines and chemokines compared to L. crispatus and PBS groups. These results suggest G. vaginalis inoculation may be increasing HSV-2 infection by disrupting the epithelial barrier, decreasing protective immune responses and increasing tissue inflammation in the vaginal tract.

A comprehensive analysis of mRNA expression profiles of Esophageal Squamous Cell Carcinoma reveals downregulation of Desmoglein 1and crucial genomic targets.

Esophageal Squamous Cell Carcinoma (ESCC) is a histological subtype of esophageal cancer that begins in the squamous cells in the esophagus. In only 19% of the ESCC-diagnosed patients, a five-year survival rate has been seen. This necessitates the identification of high-confidence biomarkers for early diagnosis, prognosis, and potential therapeutic targets for the mitigation of ESCC. We performed a meta-analysis of 10 mRNA datasets and identified consistently perturbed genes across the studies. Then, integrated with ESCC ATLAS to segregate 'core' genes to identify consequences of primary gene perturbation events leading to gene-gene interactions and dysregulated molecular signaling pathways. Further, by integrating with toxicogenomics data, inferences were drawn for gene interaction with environmental exposures, trace elements, chemical carcinogens, and drug chemicals. We also deduce the clinical outcomes of candidate genes based on survival analysis using the ESCC related dataset in The Cancer Genome Atlas. We identified 237 known and 18 novel perturbed candidate genes. Desmoglein 1 (DSG1) is one such gene that we found significantly downregulated (Fold Change =-1.89, p-value = 8.2e-06) in ESCC across six different datasets. Further, we identified 31 'core' genes (that either harbor genetic variants or are regulated by epigenetic modifications) and found regulating key biological pathways via adjoining genes in gene-gene interaction networks. Functional enrichment analysis showed dysregulated biological processes and pathways including "Extracellular matrix", "Collagen trimmer" and "HPV infection" are significantly overrepresented in our candidate genes. Based on the toxicogenomic inferences from Comparative Toxicogenomics Database we report the key genes that interacted with risk factors such as tobacco smoking, zinc, nitroso benzylmethylamine, and drug chemicals such as cisplatin, Fluorouracil, and Mitomycin in relation to ESCC. We also point to the STC2 gene that shows a high risk for mortality in ESCC patients. We identified novel perturbed genes in relation to ESCC and explored their interaction network. DSG1 is one such gene, its association with microbiota and a clinical presentation seen commonly with ESCC hints that it is a good candidate for early diagnostic marker. Besides, in this study we highlight candidate genes and their molecular connections to risk factors, biological pathways, drug chemicals, and the survival probability of ESCC patients.