Identification of Molecular Signatures in Mild Intrinsic Atopic Dermatitis by Bioinformatics Analysis

Assessment of Spatial and Temporal Variation in the Skin Transcriptome of Atopic Dermatitis by Use of 1.5 mm Minipunch Biopsies

Atopic dermatitis (AD) is a common inflammatory skin disorder characterized by a heterogeneous and fluctuating disease course. To obtain a detailed molecular understanding of both the temporal and spatial variation in AD, we conducted a longitudinal case-control study, in which we followed a population, the GENAD (Gentofte AD) cohort, of mild-to-moderate patients with AD and matched healthy controls for more than a year. By the use of 1.5 mm minipunch biopsies, we obtained 393 samples from lesional, nonlesional, and healthy skin from multiple anatomical regions at different time points for transcriptomic profiling. We observed that the skin transcriptome was remarkably stable over time, with the largest variation being because of disease, individual, and skin site. Numerous AD-specific, differentially expressed genes were identified and indicated a disrupted skin barrier and activated immune response as the main features of AD. We also identified potentially novel targets in AD, including IL-37, MAML1, and several long noncoding RNAs. We envisage that the application of small biopsies, such as those introduced in this study, combined with omics technologies, will enable future skin research, in which multiple sampling from the same individual will give a more detailed, dynamic picture of how a disease fluctuates in time and space.

Clinical features and risk factors of IgE-independent aтopic dermatitis in children

Relevance. Atopic dermatitis (AD) is an inflammatory disease characterized by a chronic course with periods of remissions and exacerbations. IgE-independent atopic dermatitis is a medical and social problem of our time, since the disease manifests itself most often in childhood and is one of the most frequent forms of dermatoses among the pediatric population. The prevalence of atopic dermatitis among children is up to 20 %, among adults - 2-8 %. Recently, there has been a significant increase in atopic diseases worldwide. The aim: to study specific features of IgE-independent atopic dermatitis in children living in a metropolis. Materials and Methods. A prospective cohort study was conducted, which included 451 children aged 5 to 14 years with a diagnosis of AD who applied for outpatient care at the Moscow Scientific and Practical Center of Dermatovenereology and Cosmetology for the period 2020-2021. All parents (guardians) have given voluntary informed consent to the participation of children in the study and the publication of personal data. Examination of patients included general clinical methods, assessment of the SCORAD index and laboratory allergological examination (total and 73 specific IgE in blood serum with the most common food and aeroallergens). In 103 (22.8 %) children (57 (55.3 %) boys and 46 (44.7 %) girls), the results of the allergological analysis did not confirm concomitant allergic sensitization. Atopic dermatitis in these children was defined as IgE-independent. Results and Discussion. Predictors of the development of IgE-independent AD were hereditary predisposition [odds ratio (OR) 2.42; 95 % confidence interval (CI) 1.12-5.25], artificial feeding [OR 4.04; 95 % CI 1.46-11.20], comorbidities [OR 1.42; 95 % CI 0.57-3.52], late onset [OR 1.67; 95 % CI 0.81-3.41]. According to the SCORAD index, the majority of patients (75.7 %) had a moderate degree of AD and no seasonality. Features of skin rashes corresponded to the age periods of the course of AD: erythematous-squamous forms with lichenification foci prevailed. For the first time, the features of IgE-independent atopic dermatitis in children were shown. The role of risk factors for the development of IgE-independent atopic dermatitis in children has been shown for the first time. Conclusion. IgE-independent type of AD can be diagnosed in every fifth child with AD. The study of risk factors will allow predicting the development of this type of disease.

Identification of novel candidate genes and predicted miRNAs in atopic dermatitis patients by bioinformatic methods

Atopic dermatitis (AD) is a common, chronic inflammatory dermatosis with relapsing eruptions. Our study used bioinformatics to find novel candidate differentially expressed genes (DEGs) and predicted miRNAs between AD patients and healthy controls. The Mesh term "atopic dermatitis" was retrieved to obtain DEGs in GEO datasets. DEGs between AD patients and healthy controls were analyzed using GEO2R. Overlapping DEGs between different datasets were obtained with use of Draw Venn software. GO and KEGG enrichment analyses were conducted by the use of DAVID. STRING and miRWalk were used to individually analyze PPI networks, interactions of candidate genes and predicted miRNAs. A total of 571 skin samples, as retrieved from 9 databases were assessed. There were 225 overlapping DEGs between lesioned skin samples of AD patients and that of healthy controls. Nineteen nodes and 160 edges were found in the largest PPI cluster, consisting of 17 up-regulated and 2 down-regulated nodes. Two KEGG pathways were identified, including the cell cycle (CCNB1, CHEK1, BUB1B, MCM5) and p53 (CCNB1, CHEK1, GTSE1) pathways. There were 56 nodes and 100 edges obtained in the miRNA-target gene network, with has-miR-17-5p targeted to 4 genes and has-miR-106b-5p targeted to 3 genes. While these findings will require further verification as achieved with experiments involving in vivo and in vitro modles, these results provided some initial insights into dysfunctional inflammatory and immune responses associated with AD. Such information offers the potential to develop novel therapeutic targets for use in preventing and treating AD.

Insight Into Biological Targets and Molecular Mechanisms in the Treatment of Arsenic-Related Dermatitis With Vitamin A via Integrated in silico Approach

Exposure to arsenic (As), an inorganic poison, may lead to skin lesions, including dermatitis. Vitamin A (VA), a fat-soluble vitamin essential for mucous membrane integrity, plays a key role in skin protection. Although the beneficial actions of VA are known, the anti-As-related dermatitis effects of VA action remain unclear. Hence, in this study, we aimed to interpret and identify the core target genes and therapeutic mechanisms of VA action in the treatment of As-related dermatitis through integrated in silico approaches of network pharmacology and molecular docking. We integrated the key VA-biological target-signaling pathway-As-related dermatitis networks for identifying core drug targets and interaction pathways associated with VA action. The network pharmacology data indicated that VA may possess potential activity for treating As-related dermatitis through the effective regulation of core target genes. An enrichment analysis in biological processes further revealed multiple immunoregulation-associated functions, including interferon-gamma production and negative regulation of T-cell activation and production of molecular mediator of immune response. An enrichment analysis in molecular pathways mainly uncovered multiple biological signaling, including natural killer cell mediated cytotoxicity, autophagy, apoptosis, necroptosis, platelet activation involved in cell fate, and immunity regulations. Molecular docking study was used to identify docked well core target proteins with VA, including Jun, tumor protein p53 (TP53), mitogen-activated protein kinase-3 (MAPK3), MAPK1, and MAPK14. In conclusion, the potential use of VA may suppress the inflammatory stress and enhance the immunity against As-related dermatitis. In the future, VA might be useful in the treatment of dermatitis associated with As through multi-targets and multi-pathways in clinical practice.