Atopic Dermatitis Model Research Articles

NAMPT and PARylation Are Involved in the Pathogenesis of Atopic Dermatitis.

Atopic dermatitis (AD) is a chronic inflammatory skin disease of very high prevalence, especially in childhood, with no specific treatment or cure. As its pathogenesis is complex, multifactorial and not fully understood, further research is needed to increase knowledge and develop new targeted therapies. We have recently demonstrated the critical role of NAD+ and poly (ADP-ribose) (PAR) metabolism in oxidative stress and skin inflammation. Specifically, we found that hyperactivation of PARP1 in response to DNA damage induced by reactive oxygen species, and fueled by NAMPT-derived NAD+, mediated inflammation through parthanatos cell death in zebrafish and human organotypic 3D skin models of psoriasis. Furthermore, the aberrant induction of NAMPT and PARP activity was observed in the lesional skin of psoriasis patients, supporting the role of these signaling pathways in psoriasis and pointing to NAMPT and PARP1 as potential novel therapeutic targets in treating skin inflammatory disorders. In the present work, we report, for the first time, altered NAD+ and PAR metabolism in the skin of AD patients and a strong correlation between NAMPT and PARP1 expression and the lesional status of AD. Furthermore, using a human 3D organotypic skin model of AD, we demonstrate that the pharmacological inhibition of NAMPT and PARP reduces pathology-associated biomarkers. These results help to understand the complexity of AD and reveal new potential treatments for AD patients.

716 Beneficial effects of ultra fine bubble shower on a mouse model of atopic dermatitis

716 Beneficial effects of ultra fine bubble shower on a mouse model of atopic dermatitis

780 A novel antimicrobial peptide derived from insulin-like growth factor-binding protein 5 (AMP-IBP5) alleviates dermatitis-like symptoms in a mouse model of atopic dermatitis

780 A novel antimicrobial peptide derived from insulin-like growth factor-binding protein 5 (AMP-IBP5) alleviates dermatitis-like symptoms in a mouse model of atopic dermatitis

734 Innovative reconstructed atopic dermatitis model: A state-of-the-art technology to study atopic dermatitis and develop specific dermocosmetic ingredients

734 Innovative reconstructed atopic dermatitis model: A state-of-the-art technology to study atopic dermatitis and develop specific dermocosmetic ingredients

1100 Elevation of TARC by anti-IL-31 receptor antibody in a murine atopic dermatitis model

1100 Elevation of TARC by anti-IL-31 receptor antibody in a murine atopic dermatitis model

Cux1+ proliferative basal cells promote epidermal hyperplasia in chronic dry skin disease identified by single-cell RNA transcriptomics

Pathological dry skin is a disturbing and intractable healthcare burden, characterized by epithelial hyperplasia and severe itch. Atopic dermatitis (AD) and psoriasis models with complications of dry skin have been studied using single-cell RNA sequencing (scRNA-seq). However, scRNA-seq analysis of the dry skin mouse model (acetone/ether/water (AEW)-treated model) is still lacking. Here, we used scRNA-seq and in situ hybridization to identify a novel proliferative basal cell (PBC) state that exclusively expresses transcription factor CUT-like homeobox 1 (Cux1). Further in vitro study demonstrated that Cux1 is vital for keratinocyte proliferation by regulating a series of cyclin-dependent kinases (CDKs) and cyclins. Clinically, Cux1+ PBCs were increased in patients with psoriasis, suggesting that Cux1+ PBCs play an important part in epidermal hyperplasia. This study presents a systematic knowledge of the transcriptomic changes in a chronic dry skin mouse model, as well as a potential therapeutic target against dry skin-related dermatoses.

Topical emollient prevents the development of atopic dermatitis and atopic march in mice.

To investigate the effect of emollient on atopic march in a murine model of atopic dermatitis (AD). Following induction of AD with topical calcipotriol (MC903) and ovalbumin (OVA), one group of mice was treated topically with a linoleic acid-ceramide-containing emollient, while mice without emollient treatment served as disease controls. After 28 days, clinical, histological and transcriptomic analyses were performed in the skin lesions and the lung as well as serum cytokine levels. Treatments of mice with MC903 and OVA induced a typical phenotype of AD, accompanied by increased expression levels of Th2 and basophil-related genes in the lung. Topical emollients markedly decreased the severity of skin lesions and inflammatory cell infiltration. Moreover, emollient treatments significantly downregulated expression levels of AD-related genes (286 of 1450 differentially expressed genes), including those related to innate inflammation (S100a8/a9, Il1b, Defb3/6, Mmp12), chemokines (Cxcl1/3, Ccl3/4) and epidermal permeability barrier (Krt2/6b/80, Serpinb12, Lce3e, Sprr2), etc. Downregulated genes were enriched in mitochondrial OXPHOS-related pathways, while upregulated genes were mainly enriched in axon guidance and tight junctions. Moreover, topical emollient treatments decreased total serum levels of IL-4, along with substantial reductions in IgE and thymic stromal lymphopoietin (TSLP) levels. Furthermore, 187 of 275 upregulated genes in lung tissue were also significantly downregulated, including those involved in leucocyte chemotaxis (Ccl9, Ccr2, Retnlg, Ccl3, Cxcl10, Il1r2, etc.) and basophil activation (Mcpt8, Cd200r3, Fcer1a, Ms4a2). In conclusion, topical emollient not only reduces skin inflammation, but also mitigates systemic inflammation by decreasing TSLP and IgE levels. Moreover, topical emollient reduces chemokine production and basophil infiltration and activation in the lung.

Abstract 5133: Oxazolone induced atopic dermatitis mouse model using hIL-4/hIL-4Ra double knock-in mice, a preclinical mouse model for evaluating Dupilumab biosimilars

Abstract Background. Th2 cytokines (e.g. IL-4, IL-5, IL13) drive defined allergic reactions and various autoimmune and inflammatory diseases including atopic dermatitis (AD), asthma and rhinitis. IL-4Ra is a receptor shared by both IL-4 and IL-13, thus blocking of IL-4Ra could prevent both IL-4 or IL-13 mediated Th2 inflammatory response. Dupilumab (Dupixent) is a humanized anti-IL-4Ra monoclonal antibody which binds to human IL-4Ra and attenuates IL-4/IL-13 mediated Th2 inflammation. It has been approved for treating moderate to severe AD and asthma. However, since Dupilumab isn’t cross-reacting to mouse IL-4Ra, there is an unmet need for a robust mouse model to evaluate Dupilumab biosimilars at preclinical stages. In this study, we described an oxazolone induced AD model in hIL-4/hIL-4Ra double knock-in mice and its application to evaluate Dupilumab and its biosimilars. Methods. The oxazolone induce AD mouse model was established in hIL-4/hIL-4Ra double knock-in mice by repeated topical applications of Oxazolone on ears. Oxazolone-induced mice received subcutaneous injection of Dupilumab at 25 mg/kg or 50 mg/kg. Dermatitis activity was assessed by measuring ear thickness, ear skin erosion, redness and scaling every other day. Serum were collected at the study end and IgE levels were measured by ELISA. In addition, spleens were also collected and their weights were compared. Ear were collected at study end and proceeded with cytokine analysis and pathology evaluation. Results. Repeated topical application of oxazolone on mouse ears induced AD-like phenotypes including ear skin swelling, erythema and scaling, drastic elevation of IgE in serum, excessive production of human IL-4 cytokine as well as excessive inflammatory cell infiltration in ear skin, which suggests oxazolone is able to induce AD in this hIL-4/hIL-4Ra double knock-in mice. Subcutaneous injection of Dupilumab at two different doses levels, 25 mg/kg and 50 mg/kg successfully ameliorated ear skin swelling, erythema and scaling at the study end. In addition, Dupilumab at both dose levels significantly reduced the IgE level in serum and mitigated the inflammatory cell infiltration, e.g. eosinophil infiltration, in mouse ear. Furthermore, Dupilumab treatment significantly reduced mouse IL-6 and mouse KC/GRO levels in mouse ear. However, Dupilumab at both dose levels did not change the serum levels of human IL-4 as well as some other Th1 cytokines such as IFN-γ, IL-1β, TNF-α, etc. in mouse ear. Conclusion. In summary, repeated challenge with Oxazolone in hIL-4/hIL-4Ra double knock-in mice resulted in the development of AD with a Th2-like hypersensitivity, mimicking the key features and pathology of the human disease, which responded to standard of care treatment Dupilumab. This provides a valuable translational model for the evaluation of future biosimilars of Dupilumab. Citation Format: Tao Yang, Rongfei Lu, Xiaofei Xu, Likun Zhang, Dawei Wang, Xinhe Feng, Xiaoyu An, Jessie (Jingjing) Wang, Xianfei He, Carl K. Edwards. Oxazolone induced atopic dermatitis mouse model using hIL-4/hIL-4Ra double knock-in mice, a preclinical mouse model for evaluating Dupilumab biosimilars. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5133.

Antimony Compounds Associate with Atopic Dermatitis and Influence Models of Itch and Dysbiosis.

Compared to the myriad of known triggers for rhinitis and asthma, environmental exposure research for atopic dermatitis (AD) is not well established. We recently reported that an untargeted search of U.S. Environmental Protection Agency (EPA) databases versus AD rates by United States (U.S.) postal codes revealed that isocyanates, such as toluene diisocyanate (TDI), are the pollutant class with the strongest spatiotemporal and epidemiologic association with AD. We further demonstrated that (di)isocyanates disrupt ceramide-family lipid production in commensal bacteria and activate the thermo-itch host receptor TRPA1. In this report, we reanalyzed regions of the U.S. with low levels of diisocyanate pollution to assess if a different chemical class may contribute. We identified antimony compounds as the top associated pollutant in such regions. Exposure to antimony compounds would be expected from brake dust in high-traffic areas, smelting plants, bottled water, and dust from aerosolized soil. Like TDI, antimony inhibited ceramide-family lipid production in Roseomonas mucosa and activated TRPA1 in human neurons. While further epidemiologic research will be needed to directly evaluate antimony exposure with surrounding AD prevalence and severity, these data suggest that compounds which are epidemiologically associated with AD, inhibit commensal lipid production, and activate TRPA1 may be causally related to AD pathogenesis.

Advanced In Vitro Three-Dimensional Skin Models of Atopic Dermatitis.

Atopic dermatitis (AD) is one of the most prevalent inflammatory skin diseases that is characterized by eczematous rashes, intense itching, dry skin, and sensitive skin. Although AD significantly impacts the quality of life and the number of patients keeps increasing, its pathological mechanism is still unknown because of its complexity. The importance of developing new in vitro three-dimensional (3D) models has been underlined in order to understand the mechanisms for the development of therapeutics since the limitations of 2D models or animal models have been repeatedly reported. Thus, the new in vitro AD models should not only be created in 3D structure, but also reflect the pathological characteristics of AD, which are known to be associated with Th2-mediated inflammatory responses, epidermal barrier disruption, increased dermal T-cell infiltration, filaggrin down-regulation, or microbial imbalance. In this review, we introduce various types of in vitro skin models including 3D culture methods, skin-on-a-chips, and skin organoids, as well as their applications to AD modeling for drug screening and mechanistic studies.

Interactions between Malassezia and New Therapeutic Agents in Atopic Dermatitis Affecting Skin Barrier and Inflammation in Recombinant Human Epidermis Model.

Several studies have reported the pathogenic role of Malassezia in atopic dermatitis (AD); the significance of Malassezia's influence on AD needs to be further investigated. Dupilumab, a monoclonal antibody to anti-Interleukin (IL) 4Rα, and ruxolitinib, a Janus kinase (JAK)1/2 inhibitor, are the first approved biologics and inhibitors widely used for AD treatment. In this study, we aimed to investigate how Malassezia Restricta (M. restricta) affects the skin barrier and inflammation in AD and interacts with the AD therapeutic agents ruxolitinib and anti-IL4Rα. To induce an in vitro AD model, a reconstructed human epidermis (RHE) was treated with IL-4 and IL-13. M. restricta was inoculated on the surface of RHE, and anti-IL4Rα or ruxolitinib was supplemented to model treated AD lesions. Histological and molecular analyses were performed. Skin barrier and ceramide-related molecules were downregulated by M. restricta and reverted by anti-IL4Rα and ruxolitinib. Antimicrobial peptides, VEGF, Th2-related, and JAK/STAT pathway molecules were upregulated by M. restricta and suppressed by anti-IL4Rα and ruxolitinib. These findings show that M. restricta aggravated skin barrier function and Th2 inflammation and decreased the efficacy of anti-IL4Rα and ruxolitinib.

Regnase-1 plays an essential role in maintaining skin immune homeostasis via regulation of chemokine expression

Regnase-1 is an endoribonuclease that regulates the stability of target genes. Here, we investigated whether Regnase-1 plays a regulatory role in the pathophysiology of atopic dermatitis, a chronic inflammatory skin disease. Regnase-1 levels were decreased in skin and serum of atopic dermatitis patients and mice. Regnase-1+/- mice exhibited more severe atopic dermatitis symptoms than wild-type mice in a house dust mite allergen-induced atopic dermatitis model. Regnase-1 deficiency led to the global changes in gene expression related with innate immune and inflammatory responses, in particular chemokines. The skin Regnase-1 level had an inverse relationship with chemokine expression when we analyzed samples of atopic dermatitis patients and Regnase-1-deficient mice, suggesting that potentiated chemokine production contributes to the augmented inflammation at lesion sites. Subcutaneous administration of recombinant Regnase-1 to mice significantly ameliorated atopic dermatitis-like skin inflammation with reduced chemokine production in a house dust mite-induced atopic dermatitis NC/Nga mouse model. These results indicate that Regnase-1 plays an essential role in maintaining skin immune homeostasis as a regulator of chemokine expression. Modulating Regnase-1 activity may be an efficient therapeutic strategy for treating chronic inflammatory diseases, including atopic dermatitis.

Experimental models of atopic dermatitis for preclinical researches

Introduction. The development of new methods and technologies for the treatment of atopic dermatitis (AtD) is an urgent medical task due to the growing incidence of the disease, increasing frequency of severe, continuously relapsing forms of dermatosis resistant to both external and systemic therapy. Appropriate experimental models of laboratory animals are needed to test new methods of AtD treatment. The purpose of the study is to describe the technologies of creating experimental models for AtD in laboratory animals to conduct preclinical studies to evaluate the effectiveness of AtD therapy, based on foreign and domestic literature data. Materials and methods. A search in the bibliographic databases PubMed, Scopus, Web of Science, scientific electronic library Elibrary was conducted, 58 sources were selected for the literary review. Search keywords: atopic dermatitis, animal models, mouse models, preclinical studies. Results and discussion. Mouse models are mainly used to reproduce AtD. Experimental mouse models of AtD can be divided into three groups: mice that spontaneously develop skin lesions similar to AtD; models using transgenic mice that either overexpress selective molecules or lack them; models induced cutaneous application of sensitizers. Typically, these models mimic various aspects of human AtD pathophysiology, such as defects in the skin barrier, Th2 predominance, with additional activation of Th1 and Th22 and, in some populations, Th17 immune response. Conclusion. Of the technologies for creating experimental models of AtD in laboratory animals, those with genetic predisposition and allergen-induced models are the closest to human AtD.

TMEM232 promotes the inflammatory response in atopic dermatitis via the nuclear factor-κB and signal transducer and activator of transcription 3 signalling pathways.

Our group previously found that the transmembrane protein 232 (TMEM232) gene was associated with atopic dermatitis (AD) by genome-wide association study and fine mapping study. However, its function is unclear so far. To investigate the roles and mechanisms of TMEM232 in AD. The expression of TMEM232 was investigated in skin lesions of patients with AD, the MC903-induced AD mouse model, human primary keratinocytes and immortalized human keratinocyte cell line (HaCaT) cells stimulated with different inflammatory factors. The role of TMEM232 in AD was analysed in HaCaT cells and Tmem232 knockout (Tmem232-/-) mice. Tmem232-specific small interfering RNA (siRNA) was used to evaluate its therapeutic potential in the AD mouse model. The expression of TMEM232 was significantly increased in skin lesions of patients with AD, the MC903-induced AD mouse model and human primary keratinocytes and HaCaT cells stimulated with different inflammatory factors compared with controls. In the presence of MC903, Tmem232-/- mice exhibited significantly reduced dermatitis severity, mast-cell infiltration in the back, and expression of T-helper (Th)1 and Th2-related inflammatory factors in skin tissue compared with wild-type mice. In vitro and in vivo experiments further showed that upregulation of TMEM232 in AD exacerbated the inflammation response through activating the pathway of nuclear factor-κB and signal transducer and activator of transcription (STAT) 3, and was regulated by the interleukin-4/STAT6 axis, which formed a self-amplifying loop. Finally, topical application of Tmem232 siRNA markedly ameliorated AD-like lesions in the AD model. This study is the first to outline the function of TMEM232. It is involved in regulating inflammation in AD and may be a potential target for AD treatment.

Osthole relieves skin damage and inhibits chronic itch through modulation of Akt/ZO-3 pathway in atopic dermatitis

Atopic dermatitis (AD) is the most prevalent chronic inflammatory skin condition and significantly reduces quality of life. Tight junction (TJ), which is located directly beneath the stratum corneum, maintains skin barrier function and aids in the identification of the cell's "territory". We evaluated seventeen TJ related genes to explore AD related alterations of TJ. Remarkably, we found that the expression of ZO-3, a gene that had not been linked to the development of TJ in AD, was significantly down-regulated in the skin of AD mice and patients. siRNA mediated knock-down of ZO-3 significantly decreased transepithelial electrical resistance in HaCaT cells, demonstrating that ZO-3 is essential to epidermal barrier function. In addition to ZO-3 downregulation, protein kinase B (Akt) phosphorylation was increased in the skin of AD mice. We further confirmed an inverse relationship between Akt phosphorylation and ZO-3 expression in AD using HaCaT cells and mouse model. Finally, we tested the efficacy of osthole as a treatment for AD in mice and HaCaT cells. Osthole inhibits Akt phosphorylation, and thereby enhances ZO-3 expression in mouse models of AD, resulting in greatly lessened AD associated skin damage and chronic itch, and osthole also increased the expression of ZO-3 in HaCaT cells by inhibiting the phosphorylation of Akt. Together, we established that ZO-3 is essential for the development of TJ in AD skin and HaCaT cells, and our findings provide fresh support for osthole's ability to protect ZO-3 expression and the epidermal barrier in AD.

Anti-Atopic Dermatitis Effects of Abietic Acid Isolated from Rosin under Condition Optimized by Response Surface Methodology in DNCB-Spread BALB/c Mice.

Abietic acid (AA) is known to have beneficial effects on inflammation, photoaging, osteoporosis, cancer, and obesity; however, its efficacy on atopic dermatitis (AD) has not been reported. We investigated the anti-AD effects of AA, which was newly isolated from rosin, in an AD model. To achieve this, AA was isolated from rosin under conditions optimized by response surface methodology (RSM), and its effects on cell death, iNOS-induced COX-2 mediated pathway, inflammatory cytokine transcription, and the histopathological skin structure were analyzed in 2,4-dinitrochlorobenzene (DNCB)-treated BALB/c mice after treatment with AA for 4 weeks. AA was isolated and purified through isomerization and reaction-crystallization under the condition (HCl, 2.49 mL; reflux extraction time, 61.7 min; ethanolamine, 7.35 mL) established by RSM, resulting in AA with a purity and extraction yield of 99.33% and 58.61%, respectively. AA exhibited high scavenging activity against DPPH, ABTS, and NO radicals as well as hyaluronidase activity in a dose-dependent manner. The anti-inflammatory effects of AA were verified in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages through amelioration of the inflammatory response, including NO production, iNOS-induced COX-2 mediated pathway activation, and cytokine transcription. In the DNCB-treated AD model, the skin phenotypes, dermatitis score, immune organ weight, and IgE concentration were significantly ameliorated in the AA cream (AAC)-spread groups compared to the vehicle-spread group. In addition, AAC spread ameliorated DNCB-induced deterioration of skin histopathological structure through the recovery of the thickness of the dermis and epidermis and the number of mast cells. Furthermore, activation of the iNOS-induced COX-2 mediated pathway and increased inflammatory cytokine transcription were ameliorated in the skin of the DNCB+AAC-treated group. Taken together, these results indicate that AA, newly isolated from rosin, exhibits anti-AD effects in DNCB-treated AD models, and has the potential to be developed as a treatment option for AD-related diseases.

Diisocyanates influence models of atopic dermatitis through direct activation of TRPA1.

We recently used EPA databases to identify that isocyanates, most notably toluene diisocyanate (TDI), were the pollutant class with the strongest spatiotemporal and epidemiologic association with atopic dermatitis (AD). Our findings demonstrated that isocyanates like TDI disrupted lipid homeostasis and modeled benefit in commensal bacteria like Roseomonas mucosa through disrupting nitrogen fixation. However, TDI has also been established to activate transient receptor potential ankyrin 1 (TRPA1) in mice and thus could directly contribute to AD through induction of itch, rash, and psychological stress. Using cell culture and mouse models, we now demonstrate that TDI induced skin inflammation in mice as well as calcium influx in human neurons; each of these findings were dependent on TRPA1. Furthermore, TRPA1 blockade synergized with R. mucosa treatment in mice to improve TDI-independent models of AD. Finally, we show that the cellular effects of TRPA1 are related to shifting the balance of the tyrosine metabolites epinephrine and dopamine. This work provides added insight into the potential role, and therapeutic potential, or TRPA1 in the pathogenesis of AD.

Thymic stromal lymphopoietin rather than IL-33 drives food allergy after epicutaneous sensitization to food allergen

A major route of sensitization to food allergen is through an impaired skin barrier. IL-33 and thymic stromal lymphopoietin (TSLP) have both been implicated in epicutaneous sensitization and food allergy, albeit in different murine models. We assessed the respective contributions of TSLP and IL-33 to the development of atopic dermatitis (AD) and subsequent food allergy in TSLP and IL-33 receptor (ST2)-deficient mice using an AD model that does not require tape stripping. TSLP receptor (TSLPR)-/-, ST2-/-, and BALB/cJ control mice were exposed to 3 weekly epicutaneous skin patches of one of saline, ovalbumin (OVA), or a combination of OVA and Aspergillus fumigatus (ASP), followed by repeated intragastric OVA challenges and development of food allergy. ASP and/or OVA patched, but not OVA-alone patched, BALB/cJ mice developed an AD-like skin phenotype. However, epicutaneous OVA sensitization occurred in OVA patched mice and was decreased in ST2-/- mice, resulting in lower intestinal mast cell degranulation and accumulation, as well as OVA-induced diarrhea occurrences on intragastric OVA challenges. In TSLPR-/- mice, intestinal mast cell accumulation was abrogated, and no diarrhea was observed. AD was significantly milder in OVA+ ASP patched TSLPR-/- mice compared to wild type and ST2-/- mice. Accordingly, intestinal mast cell accumulation and degranulation were impaired in OVA+ ASP patched TSLPR-/- mice compared to wild type and ST2-/- mice, protecting TSLPR-/- mice from developing allergic diarrhea. Epicutaneous sensitization to food allergen and development of food allergy can occur without skin inflammation and is partly mediated by TSLP, suggesting that prophylactic targeting of TSLP may be useful in mitigating the development of AD and food allergy early in life in at-risk infants.

A Mouse Model of MC903-Induced Atopic Dermatitis.

Atopic dermatitis (AD) is a chronic, relapsing, and extremely pruritic inflammatory skin disease with a particular impact on children. AD pathogenesis is not yet fully understood, and there is no curative treatment for this disease. Therefore, several genetically or chemically-induced AD mouse models have been developed. These preclinical mouse models are an indispensable research tool for studying AD pathogenesis and evaluating the efficacy of new candidate AD therapeutics. A commonly used mouse model of AD has been developed using the topical application of a low-calcemic analog of vitamin D3, MC903, to induce AD-like inflammatory phenotypes that closely resemble human AD. Moreover, this model shows a minimal effect on systemic calcium metabolism that is observed in the vitamin D3-induced AD model. Thus, an expanding number of studies use the MC903-induced AD model to interrogate AD pathobiology in vivo and to test new candidate small molecule and monoclonal antibody therapies. This protocol describes in detail functional measurements including the measurement of skin thickness, which is a surrogate marker for ear skin inflammation, as well as itch assessment, histological evaluation to assess the structural changes associated with AD skin inflammation, and preparation of single-cell suspensions from ear skin and draining lymph nodes for the assessment of inflammatory leukocyte subset infiltration in these tissues using flow cytometry. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol: Topical application of MC903 induces AD-like skin inflammation Support Protocol 1: Measurement of ear skin thickness Support Protocol 2: Itch assessment Support Protocol 3: Dissection of ear skin and ear draining lymph nodes Support Protocol 4: Histological evaluation and quantification Support Protocol 5: Preparation of single-cell suspension from ear skin and draining lymph nodes for the assessment of inflammatory immune cell infiltration using flow cytometry.

Machine learning-based prediction models for atopic dermatitis diagnosis and evaluation

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease seriously affecting the quality of life of patients. Reliable and accurate evaluation methods are necessary for early diagnosis and effective AD treatment. Thus, this study used machine learning (ML) to explore a novel diagnostic and therapeutic effect evaluation model for AD. Firstly, candidate model genes were screened from an integrated data set of four AD-related microarray datasets: GSE133477, GSE32924, GSE58558, and GSE107361, using Robust Rank Aggregation (RRA), and protein-protein interaction network (PPI). Next, three recognized models (REC) and three AD-associated gene models (AAG) established with LASSO, Logistic linear regression (LR), and random forest (RF) were developed and tested separately using GSE130588 and GSE99802 datasets. The results revealed that REC model of LASSO (model genes including IL7R, KRT16, CCL2, CD53, CCL18 and CCL22), REC model of LR(including IL7R, KRT16, CCL18) and AAG model of LR (including MX1, CCNB1, SERPINB13, ADAM19, CEP55, VMP1, TTC39A, and FCHSD1) accurately classified AD lesions and non-lesions based on the good AUCs (LASSO (REC):0.8761, and LR (REC and AAG):0.8302 in GSE130588; LASSO (REC): 0.7761, and LR (REC and AAG):0.8783 in GSE99802). In Dupilumab, Crisaborole, and fezakinumab-treated samples, the LASSO (REC) and LR(AAG) models were positively correlated with SCORD (Pearson correlation coefficients of 0.55 and 0.69, respectively) and negatively correlated with the treatment length. In addition, the two models also accurately predicted the infiltration of immune cells in the skin lesions and non-lesions. Therefore, the ML-based predictive model provides a new approach to predicting AD diagnosis and the therapeutic effect of AD treatment options.