Desmoglein Research Articles

P106Reasonable similarities: relatives with biventricular arrhythmogenic cardiomyopathy and mutation in the DSG2 gene

P106Reasonable similarities: relatives with biventricular arrhythmogenic cardiomyopathy and mutation in the DSG2 gene

Associations of anti-desmoglein antibodies with clinical phenotypes and disease activity in pemphigus patients and their change patterns

Objective To investigate associations of anti-desmoglein (Dsg1 and Dsg3) antibodies detected by enzyme-linked immunosorbent assay (ELISA) with clinical phenotypes and disease activity in pemphigus patients, and to explore their change patterns. Methods A total of 111 patients with pemphigus were enrolled from Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College between January 2015 and January 2018. ELISA was performed to detect serum levels of anti-Dsg1 and anti-Dsg3 antibodies in these patients with different clinical types of pemphigus at different stages, including onset stage, control stage (no new erythema or vesicles occurred in the last 2 or more weeks, and primary lesions began to regress) , maintenance stage (the condition had been stable for ≥ 1 month, and treatment was maintained with a low dose of glucocorticoids [prednisone equivalent of < 15 mg/d]) , and recurrence stage, and the change patterns of serum levels of anti-Dsg1 and anti-Dsg3 antibodies were analyzed. Statistical analysis was carried out with SPSS 22 software by using one-way analysis of variance for the comparison among groups, and least significant difference (LSD) -t test for multiple comparisons. Results At the disease onset stage, control stage, maintenance stage and recurrence stage, 92, 53, 33, and 9 patients respectively completed the detection. Among the 92 patients with initial onset of pemphigus, the positive rates of anti-Dsg1 and anti-Dsg3 antibodies were 100% and 2.77% respectively in 36 patients with pemphigus foliaceus, 20% and 80% respectively in 10 with mucosal-dominant pemphigus vulgaris, and 97.82%, 95.65% respectively in 46 with mucocutaneous pemphigus vulgaris. The serum levels of anti-Dsg1 antibodies in the patients with pemphigus foliaceus significantly differed among the disease onset stage, control stage, maintenance stage and recurrence stage (137.43 ± 77.74, 13.94 ± 14.81, 21.50 ± 58.33, 121.13 ± 86.89 U/ml, respectively) , the serum levels of anti-Dsg3 antibodies in the patients with mucosal-dominant pemphigus vulgaris also significantly differed among the above clinical stages (125.61 ± 94.81, 34.5 ± 16.26, 0.6, 258 U/ml, respectively) , and the serum levels of anti-Dsg1 and anti-Dsg3 antibodies in patients with mucocutaneous pemphigus vulgaris both significantly differed among the above clinical stages (anti-Dsg1 antibody: 115.39 ± 70.62, 15.74 ± 25.10, 3.62 ± 12.09, 78.60 ± 92.25 U/ml, respectively; anti-Dsg3 antibody: 137.98 ± 81.25, 58.14 ± 63.46, 29.26 ± 64.70, 136.9 ± 101.47 U/ml, respectively) . Additionally, the serum levels of anti-Dsg1 antibodies in the patients with pemphigus foliaceus, as well as the serum levels of anti-Dsg3 antibodies in the patients with mucosal-dominant pemphigus vulgaris and those with mucocutaneous pemphigus vulgaris, were both significantly lower at the disease control stage and maintenance stage than at the disease onset stage and recurrence stage (all P < 0.05) . During the treatment, epitope spreading occurred in 2 patients, and high-titer anti-Dsg antibodies were observed in 4 patients at the stable stage. Conclusion Anti-Dsg antibody spectrum is associated with clinical phenotypes of pemphigus, and its serum levels measured by ELISA can be applied to disease activity monitoring and evaluation of therapeutic efficacy. Key words: Pemphigus; Desmoglein 1; Desmoglein 3; Clinical phenotype; Disease activity

A potential link between desmoglein 3 and epidermal growth factor receptor in oral squamous cell carcinoma and its effect on cetuximab treatment efficacy.

Desmoglein (DSG) 3 is overexpressed in oral squamous cell carcinoma (OSCC). Epidermal growth factor receptor (EGFR) inhibitor cetuximab is widely used for OSCC treatment. Several evidences suggest a correlation between DSG3 and EGFR in epidermal keratinocytes. EGFR inhibition has been shown to enhance cell-cell adhesion and induce terminal differentiation in epidermal cells. Thus, here we investigated the DSG3-EGFR interaction in OSCC and its effect on cetuximab treatment. Cell lines established from the primary tumor and metastatic lymph nodes of four OSCC patients and three commercial OSCC cell lines were used for the experiments. Cells from metastatic lymph nodes of each patient expressed increased DSG3 and EGFR than cells from the primary tumor in the same patient. Cetuximab treatment increased DSG3 expression by up to 3.5-fold in seven of the 11 cell lines. A high calcium concentration increased the expression of DSG3 and EGFR in a dose-dependent manner. Strikingly, a high calcium-associated DSG3 induction enhanced cetuximab efficacy by up to 23% increase in cetuximab-low-sensitive cell lines. Our findings also suggest a correlation between DSG3 and EGFR in OSCC, and this affects cetuximab treatment efficacy.

Desmoglein 3 Silencing Inhibits Inflammation and Goblet Cell Mucin Secretion in a Mouse Model of Chronic Rhinosinusitis via Disruption of the Wnt/β-Catenin Signaling Pathway.

Chronic rhinosinusitis (CRS) is a common disease characterized by inflammation of the nose and paranasal sinuses lasting over 12weeks. This study aims to evaluate the effect of desmoglein 3 (DSG3) on inflammatory response and goblet cell mucin secretion in a mouse model of CRS. The CRS-related differentially expressed genes and disease genes were screened using microarray-based gene expression analysis. Subsequently, CRS mouse models were established. The levels of pro-inflammatory factors TNF-α, IL-6, and IL-8 were measured by ELISA. In addition, loss-of-function experiment was conducted using siRNAs targeting DSG3 and β-catenin. The secretion of mucins MUC5B and MUC5AC in goblet cells was detected, and the apoptosis of goblet cells was assessed. The regulatory effect of DSG3 on the Wnt/β-catenin signaling pathway was analyzed by determining the mRNA and protein levels of DSG3, Wnt, β-catenin, and GSK3β. DSG3 was identified to be an upregulated gene in CRS, which was further documented in CRS mice models. Elevated inflammation and mucin production were noted in CRS mice models. Also, it was found that DSG3 or β-catenin silencing could decrease the levels of TNF-α, IL-6, and IL-8, and the positive rates of MUC5B and MUC5AC while enhancing goblet cell apoptosis. The Wnt/β-catenin signaling pathway was blocked by DSG3, evidenced by downregulated Wnt and β-catenin as well as upregulated GSK3β mRNA and protein levels. Overall, this study provides evidence that silencing DSG3 could inhibit the activation of the Wnt/β-catenin signaling pathway, thus alleviating CRS.

In Vitro Cultivation of Limbal Epithelial Stem Cells on Surface-Modified Crosslinked Collagen Scaffolds.

Purpose To investigate the efficacy of recombinant human collagen type I (RHC I) and collagen-like peptide (CLP) hydrogels as alternative carrier substrates for the cultivation of limbal epithelial stem cells (LESC) under xeno-free culture conditions. Methods Human LESC were cultivated on seven different collagen-derived hydrogels: (1) unmodified RHC I, (2) fibronectin-patterned RHC I, (3) carbodiimide-crosslinked CLP (CLP-12 EDC), (4) DMTMM- (4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium-) crosslinked CLP (CLP-12), (5) fibronectin-patterned CLP-12, (6) “3D limbal niche-mimicking” CLP-12, and (7) DMTMM-crosslinked CLP made from higher CLP concentration solution. Cell proliferation, cell morphology, and expression of LESC markers were analyzed. All data were compared to cultures on human amniotic membrane (HAM). Results Human LESC were successfully cultivated on six out of seven hydrogel formulations, with primary cell cultures on CLP-12 EDC being deemed unsuccessful since the area of outgrowth did not meet quality standards (i.e., inconsistence in outgrowth and confluence) after 14 days of culture. Upon confluence, primary LESC showed high expression of the stem cell marker ΔNp63, proliferation marker cytokeratin (KRT) 14, adhesion markers integrin-β4 and E-cadherin, and LESC-specific extracellular matrix proteins laminin-α1, and collagen type IV. Cells showed low expression of differentiation markers KRT3 and desmoglein 3 (DSG3). Significantly higher gene expression of KRT3 was observed for cells cultured on CLP hydrogels compared to RHC I and HAM. Surface patterning of hydrogels influenced the pattern of proliferation but had no significant effect on the phenotype or genotype of cultures. Overall, the performance of RHC I and DMTMM-crosslinked CLP hydrogels was equivalent to that of HAM. Conclusion RHC I and DMTMM-crosslinked CLP hydrogels, irrespective of surface modification, support successful cultivation of primary human LESC using a xeno-free cultivation protocol. The regenerated epithelium maintained similar characteristics to HAM-based cultures.

In vitro analysis of arrhythmogenic cardiomyopathy associated desmoglein-2 (DSG2) mutations reveals diverse glycosylation patterns

Arrhythmogenic right ventricular cardiomyopathy is a heritable cardiac disease causing severe ventricular arrhythmias, heart failure and sudden cardiac death. It is mainly caused by mutations in genes encoding several structural proteins of the cardiac desmosomes including the DSG2 gene encoding the desmosomal cadherin desmoglein-2.Although the molecular structure of the extracellular domain of desmoglein-2 is known, it remains an open question, how mutations in DSG2 contribute to the pathogenesis of arrhythmogenic right ventricular cardiomyopathy. In the present study, we analyzed the impact of different DSG2 mutations on the glycosylation pattern using de-glycosylation assays, lectin blot analysis and genetic inhibition studies. Remarkably, wildtype and mutant desmoglein-2 displayed different glycosylation patterns, although the investigated DSG2 mutations do not directly affect the consensus sequences of the N-glycosylation sites.Our study reveals complex molecular interactions between DSG2 mutations and N-glycosylations of desmoglein-2, which may contribute to the molecular understanding of the patho-mechanisms associated with arrhythmogenic right ventricular cardiomyopathy.

Analysis of gene co‑expression network reveals prognostic significance of CNFN in patients with head and neck cancer.

In patients with head and neck cancer (HNC), lymph node (N) metastases are associated with cancer aggressiveness and poor prognosis. Identifying meaningful gene modules and representative biomarkers relevant to the N stage helps predict prognosis and reveal mechanisms underlying tumor progression. The present study used a step-wise approach for weighted gene co-expression network analysis (WGCNA). Dataset GSE65858 was subjected to WGCNA. RNA sequencing data of HNC downloaded from the Cancer Genome Atlas (TCGA) and dataset GSE39366 were utilized to validate the results. Following data preprocessing, 4,295 genes were screened, and blue and black modules associated with the N stage of HNC were identified. A total of 16 genes [keratinocyte differentiation associated protein, suprabasin, cornifelin (CNFN), small proline rich protein 1B, desmoglein 1 (DSG1), chromosome 10 open reading frame 99, keratin 16 pseudogene 3, gap junction protein β2, dermokine, LY6/PLAUR domain containing 3, transmembrane protein 79, phospholipase A2 group IVE, transglutaminase 5, potassium two pore domain channel subfamily K member 6, involucrin, kallikrein related peptidase 8] that had a negative association with the N-stage in the blue module, and two genes (structural maintenance of chromosomes 4 and mutS homolog 6) that had a positive association in the black module, were identified to be candidate hub genes. Following further validation in TCGA and dataset GSE65858, it was identified that CNFN and DSG1 were associated with the clinical stage of HNC. Survival analysis of CNFN and DSG1 was subsequently performed. Patients with increased expression of CNFN displayed better survival probability in dataset GSE65858 and TCGA. Therefore, CNFN was selected as the hub gene for further verification in the Gene Expression Profiling Interactive Analysis database. Finally, functional enrichment and gene set enrichment analyses were performed using datasets GSE65858 and GSE39366. Three gene sets, namely ‘P53 pathway’, ‘estrogen response early’ and ‘estrogen response late’, were enriched in the two datasets. In conclusion, CNFN, identified via the WGCNA algorithm, may contribute to the prediction of lymph node metastases and prognosis, probably by regulating the pathways associated with P53, and the early and late estrogen response.

Pemphigus vegetans: A rare variant of pemphigus vulgaris

Pemphigus vegetans (PV) is a rare clinical variant of pemphigus vulgaris and comprises up to 1%–2% of all pemphigus cases. It is characterized by vegetative plaques in the inguinal folds, flexural areas, oral mucosa, trunk, and thighs. It is accompanied by the presence of autoantibodies against desmoglein-3. We are presenting a case of a 36-year-old man with oral ulcers and multiple pustules in the flexural areas, inguinal region, and thighs. Systemic examination was uneventful. Skin biopsy was taken from the lesion over the thigh and subjected to light microscopy and immunofluorescence examinations. Based on clinical findings, histopathological characteristics, and direct immunofluorescence, a final diagnosis of PV was made.

A Homozygous Nonsense Mutation in the DSG3 Gene Causes Acantholytic Blisters in the Oral and Laryngeal Mucosa

A Homozygous Nonsense Mutation in the DSG3 Gene Causes Acantholytic Blisters in the Oral and Laryngeal Mucosa

Sequence Characterization of DSG3 Gene to Know Its Role in High-Altitude Hypoxia Adaptation in the Chinese Cashmere Goat.

The Tibetan cashmere goat is one of the main goat breeds used by people living in the plateau. It exhibits the distinct phenotypic characteristics observed in lowland goats, allowing them to adapt to the challenging conditions at high altitudes. It provides an ideal model for understanding the genetic mechanisms underlying high-altitude adaptation and hypoxia-related diseases. Our previous exome sequencing of five Chinese cashmere breeds revealed a candidate gene, DSG3 (Desmoglein 3), responsible for the high-altitude adaptation of the Tibetan goat. However, the whole DSG3 gene (44 kbp) consisting of 16 exons in the goat genome was not entirely covered by the exome sequencing. In this study, we resequenced all the 16 exons of the DSG3 gene in ten Chinese native goat populations. Twenty-seven SNP variants were found between the lowland and highland goat populations. The genetic distance (FST) of significant SNPs between the lowland and highland populations ranged from 0.42 to 0.58. By using correlation coefficient analysis, linkage disequilibrium, and haplotype network construction, we found three non-synonymous SNPs (R597E, T595I, and G572S) in exon 5 and two synonymous SNPs in exons 8 and 16 in DSG3. These mutations significantly segregated high- and low-altitude goats in two clusters, indicating the contribution of DSG3 to the high-altitude hypoxia adaptation in the Tibetan goat.

Generation of an anti-desmoglein 3 antibody without pathogenic activity of pemphigus vulgaris for therapeutic application to squamous cell carcinoma

It is ideal for the target antigen of a cytotoxic therapeutic antibody against cancer to be cancer-specific, but such antigens are rare. Thus an alternative strategy for target selection is necessary. Desmoglein 3 (DSG3) is highly expressed in lung squamous cell carcinoma, while it is well-known that anti-DSG3 antibodies cause pemphigus vulgaris, an autoimmune disease. We evaluated DSG3 as a novel target by selecting an epitope that exerts efficacy against cancer with no pathogenic effects in normal tissues. Pathogenic anti-DSG3 antibodies induce skin blisters by inhibiting the cell–cell interaction in a Ca2+-dependent manner. We screened anti-DSG3 antibodies that bind DGS3 independent of Ca2+ and have high antibody-dependent cell cytotoxicity (ADCC) activity against DSG3-expressing cells. These selected antibodies did not inhibit cell–cell interaction and showed ADCC activity against squamous cell carcinoma cell lines. Furthermore, one of the DSG3 antibodies showed anti-tumour activity in tumour mouse models but did not induce adverse effects such as blister formation in the skin. Thus it was possible to generate an antibody against DSG3 by using an appropriate epitope that retained efficacy with no pathogenicity. This approach of epitope selection may expand the variety of druggable target molecules.

Autoreactive IgG and IgA B Cells Evolve through Distinct Subclass Switch Pathways in the Autoimmune Disease Pemphigus Vulgaris

SUMMARYLineage analysis of autoreactive B cells can reveal the origins of autoimmunity. In the autoimmune disease pemphigus vulgaris (PV), desmoglein 3 (DSG3) and DSG1 autoantibodies are predominantly of the IgG4 subclass and less frequently of IgG1 and IgA subclasses, prompting us to investigate whether anti-DSG IgG4 B cells share lineages with IgG1, IgA1, and IgA2. Combining subclass-specific B cell deep sequencing with high-throughput antibody screening, we identified 80 DSG-reactive lineages from 4 PV patients. Most anti-DSG IgG4 B cells lacked clonal relationships to other subclasses and preferentially targeted DSG adhesion domains, whereas anti-DSG IgA frequently evolved from or to other subclasses and recognized a broader range of epitopes. Our findings suggest that anti-DSG IgG4 B cells predominantly evolve independently or diverge early from other subclasses and that IgA is most often not the origin of IgG autoreactivity in PV. These data provide insight into how autoreactivity diversifies across B cell subclasses.

Desmoglein1 Deficiency Is a Potential Cause of Cutaneous Eruptions Induced by Shuanghuanglian Injection.

Cutaneous eruption is a common drug-adverse reaction, characterised by keratinocytes inflammation and apoptosis. Shuanghuanglian injeciton (SHLI) is a typical Chinese medicine injection, which is used to treat influenza. It has been reported that SHLI has the potential to induce cutaneous adverse eruptions. However, the mechanisms remain unclear. Since desmoglein 1 (DSG1) shows a crucial role in maintaining skin barrier function and cell susceptibility, we assume that DSG1 plays a critical role in the cutaneous eruptions induced by SHLI. In our study, retinoic acid (RA) was selected to downregulate the DSG1 expression, and lipopolysaccharide (LPS) was first used to identify the susceptibility of the DSG1-deficiency Hacat cells. Then, SHLI was administrated to normal or DSG1-deficient Hacat cells and mice. The inflammatory factors and apoptosis rate were evaluated by RT-PCR and flow cytometry. The skin pathological morphology was observed by hematoxylin and eosin (HE) staining. Our results show that treated only with SHLI could not cause IL-4 and TNF-α mRNA increases in normal Hacat cells. However, in the DSG1-deficient Hacat cells or mice, SHLI induced an extreme increase of IL-4 and TNF-α mRNA levels, as well as in the apoptosis rate. The skin tissue showed a local inflammatory cell infiltration when treated with SHIL in the DSG1-deficient mice. Thus, we concluded that DSG1 deficiency was a potential causation of SHLI induced eruptions. These results indicated that keratinocytes with DSG1 deficiency were likely to induce the cutaneous eruptions when stimulated with other medicines.

079 Correlation of IgG autoantibodies against acetylcholine receptors and desmogleins in patients with pemphigus vulgaris treated with steroid sparing agents or rituximab

Autoantibodies against desmoglein-1 (DSG1) and desmoglein-3 (DSG3) have been shown to be important in the pathogenesis of pemphigus vulgaris (PV). In some patients, however, disease activity does not always correlate with IgG anti-DSG levels. Recent studies have indicated that other non-DSG antibodies may contribute to the pathogenesis of pemphigus, including acetylcholine receptor (AchR) autoantibodies. The purpose of this study is to retrospectively analyze PV patient sera to better understand the role of IgG anti-AchR antibodies in patients treated with prednisone and steroid sparing agents (SSA; n=15) or prednisone and rituximab (n=14). Patients were evaluated at two time points, T1 and T2, with a median interval between evaluations of 970 days for SSA treated subjects and 780 days for those treated with rituximab. Sera were tested for the presence of DSG1, DSG3, and AchR IgG autoantibodies by ELISA. Disease activity was assessed using the Pemphigus Disease Area Index (PDAI). Disease activity significantly decreased in both SSA (p<.0001) and rituximab (p<.0001) groups from T1 to T2. Sera from PV patients showed a significantly higher AchR antibody concentration compared to Normal Controls (median PV=19.8 ng/mL, median NC=16.9 ng/mL, p=.0087). No correlation was found between anti-DSG1 or -DSG3 IgG and IgG anti-AchR antibody levels in either treatment group at T1 or T2. A significant difference in paired IgG anti-DSG1 (p<.0001) and anti-DSG3 (p=.0002) levels between T1 and T2 was found in both SSA and rituximab subjects. No significant difference, however, was seen in paired AchR autoantibody levels between T1 and T2 in either treatment group. These findings demonstrate that although IgG anti-AchR autoantibodies were present in PV subjects, they did not decrease with either SSA or rituximab therapy and did not correlate with anti-DSG1 or -DSG3 IgG autoantibody levels.

Exogenous oestrogen inhibits genital transmission of cell-associated HIV-1 in DMPA-treated humanized mice.

IntroductionHIV affects more women than any other life‐threatening infectious agent, and most infections are sexually transmitted. HIV must breach the female genital tract mucosal barrier to establish systemic infection, and clinical studies indicate virus more easily evades this barrier in women using depot‐medroxyprogesterone acetate (DMPA) and other injectable progestins for contraception. Identifying a potential mechanism for this association, we learned DMPA promotes susceptibility of wild‐type mice to genital herpes simplex virus type 2 (HSV‐2) infection by reducing genital tissue expression of the cell‐cell adhesion molecule desmoglein‐1 (DSG‐1) and increasing genital mucosal permeability. Conversely, DMPA‐mediated increases in genital mucosal permeability and HSV‐2 susceptibility were eliminated in mice concomitantly administered exogenous oestrogen (E). To confirm and extend these findings, herein we used humanized mice to define effects of systemic DMPA and intravaginal (ivag) E administration on susceptibility to genital infection with cell‐associated HIV‐1.MethodsEffects of DMPA or an intravaginal (ivag) E cream on engraftment of NOD‐scid‐IL‐2Rgcnull (NSG) mice with human peripheral blood mononuclear cells (hPBMCs) were defined with flow cytometry. Confocal microscopy was used to evaluate effects of DMPA, DMPA and E cream, or DMPA and the pharmacologically active component of the cream on vaginal tissue DSG‐1 expression and genital mucosal permeability to low molecular weight (LMW) molecules and hPBMCs. In other studies, hPBMC‐engrafted NSG mice (hPBMC‐NSG) received DMPA or DMPA and ivag E cream before genital inoculation with 106 HIV‐1‐infected hPBMCs. Mice were euthanized 10 days after infection, and plasma HIV‐1 load quantified by qRT‐PCR and splenocytes used to detect HIV‐1 p24 antigen via immunohistochemistry and infectious virus via TZM‐bl luciferase assay.ResultsWhereas hPBMC engraftment was unaffected by DMPA or E treatment, mice administered DMPA and E (cream or the pharmacologically active cream component) displayed greater vaginal tissue expression of DSG‐1 protein and decreased vaginal mucosal permeability to LMW molecules and hPBMCs versus DMPA‐treated mice. DMPA‐treated hPBMC‐NSG mice were also uniformly susceptible to genital transmission of cell‐associated HIV‐1, while no animal concomitantly administered DMPA and E cream acquired systemic HIV‐1 infection.ConclusionExogenous E administration reduces susceptibility of DMPA‐treated humanized mice to genital HIV‐1 infection.

PKP2 and DSG2 genetic variations in Latvian arrhythmogenic right ventricular dysplasia/cardiomyopathy registry patients.

Objective:The Latvian arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD-C) registry was established to determine the genetic background of ARVD-C for analyzing discovered genetic variation frequencies in the European and Latvian populations.Methods:In total, 38 patients with suspected ARVD-C were selected. The clinical parameters were defined according to the ARVD-C guidelines, PKP2 and DSG2 gene analysis was performed using the Sanger sequencing. Additionally, large deletions/duplications were analyzed using the multiplex ligation-dependent probe amplification (MLPA) analysis.Results:Twenty symptomatic patients were enrolled in the study. Typical ARVD abnormalities were found in electrocardiography for 10 (50%) patients, in Holter monitoring for 19 (95%), in transthoracic echocardiography for 20 (100%), and in cardiac magnetic resonance for 6 (30%). Different benign genetic variations were found. Three novel, unregistered, possibly benign variations were found in the PKP2 gene: c.2489+131G>A, c.2489+72delA, and c.1035-5T>C and three in the DSG2 gene: c.404G>A, c.1107G>A, and c.379-15A>G. Two genetic variations in the PKP2 gene: c.1592T>G, c.2489+1G>A are possibly pathogenic. For the first time, variation c.1592T>G, has been discovered in the homozygote form. Using the MLPA analysis, large deletions or duplications were not found.Conclusion:The prevalence of the majority of non-pathological genetic variations is similar in the Latvian ARVD-C patients and the European population. Possibly, pathogenic variations were found only in 10% of our registry patients, which could mean that PKP2 and DSG2 are not the most commonly affected genes in the Latvian population.

GW28-e0738 Whole Genome Sequence Identified a Rare Homozygous Pathogenic Mutation of DSG2 Gene in a Familial Arrhythmogenic Cardiomyopathy involving both Ventricles

This study was designed to identify the pathogenic mutation in a Chinese family with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) using the whole genome sequencing (WGS). Probands II: 1 and II: 2 underwent routine examinations for diagnosis. Genomic DNA was extracted from the

Locations of acantholysis in 71 cases of pemphigus

Objective To analyze locations of acantholysis in pemphigus vulgaris (PV) and pemphigus foliaceus (PF) , so as to explain why acantholysis in pemphigus occurs in different locations of the epidermis. Methods Clinical data, histopathological and immunopathological findings, and pemphigus antibody level values were collected from 43 patients with PV and 28 with PF, and retrospectively analyzed. Results Of the 43 patients with PV, 35 showed acantholysis in the upper basal layer, 8 in the middle-to-upper epidermis. Of the 28 patients with PF, 25 showed acantholysis in the granular layer and the upper prickle cell layer, 3 in the middle-to-lower epidermis. Patients with PF showed significantly higher levels of anti-Desmoglein 1 (Dsg1) antibody compared with patients with PV (P= 0.047) . However, there were no significant differences in the levels of anti-Dsg1 and anti-Dsg3 antibodies between PV patients who had acantholysis in the middle-to-upper epidermis and those in the upper basal layer. Conclusion Histopatho-logical examinations of PV and PF lesions show that acantholysis can occur in the middle-to-upper epidermis, as well as in the middle-to-lower epidermis, and locations of acantholysis may be associated with levels of anti-Dsg1 and anti-Dsg3 antibodies. Key words: Pemphigus; Acantholysis; Desmoglein 1; Desmoglein 3; Antibodies; Enzyme-linked immunosorbent assay

EP04.30: Fetal dilated cardiomyopathy: genetic susceptibility?

Fetal dilated cardiomyopathy (DCM) may occur as the end result of both intrinsic and extrinsic cardiac disease. We present a novel case associated with two MYH7 and DSG2 gene variants in the setting of maternal Coxsackie seropositivity. A 28 year old G4P3 with chronic hypertension presented at 31 weeks gestation for a routine growth scan. Her fetal echocardiogram at 24 weeks gestation was normal; however, repeat ultrasound demonstrated biventricular dilation, wall thickening and poor contractility (figure 1), but no hydrops. The patient reported a viral illness two weeks prior to presentation, and serum Coxsackie B titers were highly positive at 1:80. She was admitted for betamethasone administration and discharged after serial echocardiograms demonstrated stable ventricular dilation and improved function. She underwent Caesarean delivery at term for a vigorous 2860g female infant. Postnatal echo demonstrated mild right-sided dilation and low normal systolic function; however, on the fourth day of life the infant was readmitted with heart failure. Labs were notable for NT pro-BNP 614, CK 207, negative Coxsackie titers, negative metabolic panel, and two heterozygous variants of uncertain significance in MYH7 and DSG2 on microarray. The infant was started on digoxin therapy and at 4 months was developing appropriately. Supporting information can be found in the online version of this abstract Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Gene expression profiling of idiopathic interstitial pneumonias (IIPs): identification of potential diagnostic markers and therapeutic targets

BackgroundChronic fibrosing idiopathic interstitial pneumonia (IIP) is characterized by alveolar epithelial damage, activation of fibroblast proliferation, and loss of normal pulmonary architecture and function. This study aims to investigate the genetic backgrounds of IIP through gene expression profiling and pathway analysis, and to identify potential biomarkers that can aid in diagnosis and serve as novel therapeutic targets.MethodsRNA extracted from lung specimens of 12 patients with chronic fibrosing IIP was profiled using Illumina Human WG-6 v3 BeadChips, and Ingenuity Pathway Analysis was performed to identify altered functional and canonical signaling pathways. For validating the results from gene expression analysis, immunohistochemical staining of 10 patients with chronic fibrosing IIP was performed.ResultsNinety-eight genes were upregulated in IIP patients relative to control subjects. Some of the upregulated genes, namely desmoglein 3 (DSG3), protocadherin gamma-A9 (PCDHGA9) and discoidin domain-containing receptor 1 (DDR1) are implicated in cell-cell interaction and/or adhesion; some, namely collagen type VII, alpha 1 (COL7A1), contactin-associated protein-like 3B (CNTNAP3B) and mucin-1 (MUC1) are encoding the extracellular matrix molecule or the molecules involved in cell-matrix interactions; and the others, namely CDC25C and growth factor independent protein 1B (GFI1B) are known to affect cell proliferation by affecting the progression of cell cycle or regulating transcription. According to pathway analysis, alternated pathways in IIP were related to cell death and survival and cellular growth and proliferation, which are more similar to cancer than to inflammatory response and immunological diseases. Using immunohistochemistry, we further validate that DSG3, the most highly upregulated gene, shows higher expression in chronic fibrosing IIP lung as compared to control lung.ConclusionWe identified several genes upregulated in chronic fibrosing IIP patients as compared to control, and found genes and pathways implicated in cancer, rather than in inflammatory or immunological disease to play important roles in the pathogenesis of IIPs. Moreover, DSG3 is a novel potential biomarker for chronic fibrosing IIP with its significantly high expression in IIP lung.