Contrasting pathogenesis of atopic dermatitis and psoriasis--part I: clinical and pathologic concepts. J Allergy Clin Immunol. 2011;127:1110-1118. [PMID: 21388665 DOI: 10.1016/j.jaci.2011.01.053]

Regulation of MYC by CARD14 in human epithelium is a determinant of epidermal homeostasis and disease

Caspase recruitment domain family member 14 (CARD14) and its variants are associated with both atopic dermatitis (AD) and psoriasis, but their mechanistic impact on skin barrier homeostasis is largely unknown. CARD14 is known to signal via NF-κB; however, CARD14-NF-κB signaling does not fully explain the heterogeneity of CARD14-driven disease. Here, we describe a direct interaction between CARD14 and MYC and show that CARD14 signals through MYC in keratinocytes to coordinate skin barrier homeostasis. CARD14 directly binds MYC and influences barrier formation in an MYC-dependent fashion, and this mechanism is undermined by disease-associated CARD14 variants. These studies establish a paradigm that CARD14 activation regulates skin barrier function by two distinct mechanisms, including activating NF-κB to bolster the antimicrobial (chemical) barrier and stimulating MYC to bolster the physical barrier. Finally, we show that CARD14-dependent MYC signaling occurs in other epithelia, expanding the impact of our findings beyond the skin.

Happiness across the borders-A cross-sectional study among patients with psoriasis and atopic dermatitis in Europe

BACKGROUND

Dermatological research has traditionally concentrated on evaluating mental comorbidities, neglecting positive concepts like happiness. Initial studies indicate that psoriasis and atopic dermatitis (AD) impair the happiness of those affected. Considering global happiness variations, this study aimed to explore the disease- and country-specific differences in disease-related quality of life and happiness, and potential influential factors on heuristic happiness among psoriasis and AD patients in Europe.

METHODS

A cross-sectional multicentre study was conducted in dermatology departments of university-affiliated hospitals in eight European countries (Austria, Germany, Italy, Malta, Poland, Portugal, Romania and Ukraine) between October 2021 and February 2023. Adult psoriasis and AD patients completed a standardized questionnaire in their native languages, providing data on demographics, disease-related characteristics, disease-related quality of life (Dermatology Life Quality Index, DLQI), heuristic happiness, positive affect (PA), negative affect (NA) and satisfaction with life (SWL). Descriptive analysis and quantile regression were performed.

RESULTS

Between psoriasis (n = 723) and AD (n = 316) patients almost no differences were observed in happiness, SWL and NA, except for DLQI and small differences in PA, with AD patients reporting greater impact than psoriasis patients. Country-wise variation emerged in DLQI, heuristic happiness, PA, NA and SWL with Austrian patients displaying the highest levels of happiness, satisfaction and positivity, coupled with higher treatment care and lower disease severity. Quantile regression revealed varying coefficients for predictor variables across quantiles, indicating, for example positive effects on heuristic happiness associated with current or previous receipt of systemic therapies at different quantiles.

CONCLUSION

This study shows notable happiness differences across European countries and significant disease-related variations, particularly with AD patients being more impaired than psoriasis patients. The findings highlight the need for equality in treatment access and support the development of targeted positive psychological interventions to enhance happiness considering country-specific distinctions in future research and health policies for psoriasis and AD patients.

Blocking the IL-4/IL-13 Axis versus the JAK/STAT Pathway in Atopic Dermatitis: How Can We Choose?

Atopic dermatitis (AD) is an immune-mediated skin disorder with a chronic-relapsing course and a multifactorial pathogenesis. In contrast to the traditional concept of AD as solely a type 2 immune-activated disease, new findings highlight the disease as highly heterogeneous, as it can be classified into variable phenotypes based on clinical/epidemiological or molecular parameters. For many years, the only therapeutic option for moderate-severe AD was traditional immunosuppressive drugs. Recently, the area of systemic therapy of AD has significantly flourished, and many new substances are now marketed, licensed, or in the last step of clinical development. Biological agents and small molecules have enriched the therapeutic armamentarium of moderate-to-severe AD, such as dupilumab, tralokinumab, lebrikizumab (monoclonal antibodies targeting the IL-4/13 pathway), abrocitinib, upadacitinib, and baricitinib (JAK inhibitors). Indeed, the AD treatment paradigm is now split into two main approaches: targeting the IL-4/13 axis or the JAK/STAT pathway. Both approaches are valid and have strong evidence of preclinical and clinical efficacy. Therefore, the choice between the two can often be difficult and represents a major challenge for dermatologists. Indeed, several important factors must be taken into account, such as the heterogeneity of AD and its classification in phenotypes, patients' comorbidities, age, and personal preferences. The aim of our review is to provide an overview of the clinical and molecular heterogeneities of AD and to explore the factors and parameters that, in clinical practice, may help inform clinical decision-making.

Study of Genetic Mutations and Their Association With the Development of Atopic Dermatitis and Other Skin Diseases

The purpose of this study was to identify the heterogeneity of atopic dermatitis and to identify key genetic factors. This can lead to new approaches and personalized treatment strategies. I conducted a literature review of three scientific publication platforms (i.e., PubMed, Cochrane Library, Scopus) for records published between July 2011 and July 2023 using key words related to the genetics of atopic dermatitis. The high heritability and genetic pleiotropia of atopic dermatitis emphasize the importance of its genetic predisposition and interaction with concomitant diseases. The study also shows the role of various genes associated with immunity and inflammatory reactions, as well as the high heritability of atopic dermatitis, particularly among twins. Genetic mutations, specifically polymorphisms of genes encoding immune factors and inflammatory responses, determine an individual's predisposition to atopic dermatitis. Research findings also point to genetic aspects associated with other skin conditions such as psoriasis and vitiligo, confirming the existence of common genetic mechanisms between these diseases. Specifically, polymorphisms of the filaggrin gene have been found to be key genetic determinants of atopic dermatitis. I analyzed the genetic basis of atopic dermatitis, emphasizing the importance of genetic determinants and their interaction with the immune system and extracellular matrix. This study contributes to the understanding of the mechanisms of atopic dermatitis and opens new perspectives for individualized treatments.

Biologic and small-molecule therapy for treating moderate to severe atopic dermatitis: Mechanistic considerations

Atopic dermatitis (AD) is a complex and heterogeneous skin disease for which achieving complete clinical clearance for most patients has proven challenging through single cytokine inhibition. Current studies integrate biomarkers and evaluate their role in AD, aiming to advance our understanding of the diverse molecular profiles implicated. Although traditionally characterized as a TH2-driven disease, extensive research has recently revealed the involvement of TH1, TH17, and TH22 immune pathways as well as the interplay of pivotal immune molecules, such as OX40, OX40 ligand (OX40L), thymic stromal lymphopoietin, and IL-33. This review explores the mechanistic effects of treatments for AD, focusing on mAbs and Janus kinase inhibitors. It describes how these treatments modulate immune pathways and examines their impact on key inflammatory and barrier biomarkers.

SOCS1 and SOCS3 as key checkpoint molecules in the immune responses associated to skin inflammation and malignant transformation

SOCS are a family of negative inhibitors of the molecular cascades induced by cytokines, growth factors and hormones. At molecular level, SOCS proteins inhibit the kinase activity of specific sets of receptor-associated Janus Activated Kinases (JAKs), thereby suppressing the propagation of intracellular signals. Of the eight known members, SOCS1 and SOCS3 inhibit activity of JAKs mainly induced by cytokines and can play key roles in regulation of inflammatory and immune responses. SOCS1 and SOCS3 are the most well-characterized SOCS members in skin inflammatory diseases, where their inhibitory activity on cytokine activated JAKs and consequent anti-inflammatory action has been widely investigated in epidermal keratinocytes. Structurally, SOCS1 and SOCS3 share the presence of a N-terminal domain containing a kinase inhibitory region (KIR) motif able to act as a pseudo-substrate for JAK and to inhibit its activity. During the last decades, the design and employment of SOCS1 and SOCS3-derived peptides mimicking KIR domains in experimental models of dermatoses definitively established a strong anti-inflammatory and ameliorative impact of JAK inhibition on skin inflammatory responses. Herein, we discuss the importance of the findings collected in the past on SOCS1 and SOCS3 function in the inflammatory responses associated to skin immune-mediated diseases and malignancies, for the development of the JAK inhibitor drugs. Among them, different JAK inhibitors have been introduced in the clinical practice for treatment of atopic dermatitis and psoriasis, and others are being investigated for skin diseases like alopecia areata and vitiligo.

Breast Cancer-Related Lymphedema Results in Impaired Epidermal Differentiation and Tight Junction Dysfunction

Breast cancer-related lymphedema (BCRL) is characterized by skin changes, swelling, fibrosis, and recurrent skin infections. Clinical studies have suggested that lymphedema results in skin barrier defects; however, the underlying cellular mechanisms and the effects of bacterial contamination on skin barrier function remain unknown. In matched biopsies from patients with unilateral BCRL, we observed decreased expression of FLG and the tight junction protein ZO-1 in skin affected by moderate lymphedema or by subclinical lymphedema in which dermal backflow of lymph was identified by indocyanine green lymphography, relative to those in the controls (areas without backflow and from the unaffected arm). In vitro stimulation of keratinocytes with lymph fluid obtained from patients undergoing lymphedema surgery led to the same changes as well as increased expression of keratin 14, a marker of immature keratinocytes. Finally, using mouse models of lymphedema, we showed that similar to the clinical scenario, the expression of skin barrier proteins was decreased relative to that in normal skin and that colonization with Staphylococcus epidermidis bacteria amplified this effect as well as lymphedema severity. Taken together, our findings suggest that lymphatic fluid stasis contributes to skin barrier dysfunction in lymphedema.

Atopic Keratoconjunctivitis: Pathophysiology, Clinic, and Potential New Therapeutic Concepts

Atopic dermatitis (AD) is a chronic recurrent inflammatory skin disease with a bipolar age distribution in childhood, adolescence and middle adulthood. Up to 50% of AD patients show ocular involvement, which can be potentially sight threatening. Clinically, the majority of cases present with atopic blepharo(kerato)conjunctivitis or atopic keratoconjunctivitis (AKC); other clinical variants from this group of inflammatory ocular surface diseases are keratoconjunctivitis vernalis in childhood and adolescence and allergic conjunctivitis. In addition to the aforementioned blepharitis, keratitis and conjunctivitis, AD is also associated with eyelid involvement with subsequent eyelid malposition, limbal insufficiency with the development of pseudopterygia, (chronic) cicatrizing conjunctivitis with symblephara formation and fornix shortening, as well as ocular surface malignancies such as conjunctival intraepithelial neoplasia (CIN) and squamous cell carcinoma. In addition, an association with AD or AKC has been described for keratoconus. Whereas the therapy of AD in dermatology has made revolutionary advances in recent years through the use of biologicals, the primary use of these biologicals in ophthalmological complications is still very hesitant. Treatment here is often provided using topical steroids and calcineurin inhibitors. The following article summarises recent developments in basic and clinical dermatological research and discusses them in the context of current concepts for ophthalmological therapy.

Pharmacokinetic Profile of Brepocitinib with Topical Administration in Atopic Dermatitis and Psoriasis Populations: Strategy to Inform Clinical Trial Design in Adult and Pediatric Populations

INTRODUCTION

Topical brepocitinib, a tyrosine kinase (TYK)2/Janus kinase (JAK)1 inhibitor, is in development for psoriasis (PsO) and atopic dermatitis (AD). Quantitative analyses of prior clinical trial data were used to inform future clinical trial designs.

METHODS

Two phase 2b studies in patients with AD and PsO were used to characterize the amount of topical brepocitinib and the resultant systemic trough concentration (CTrough) using a linear mixed-effects regression (LMER). This model was used to predict brepocitinib systemic CTrough for higher treated body surface areas (BSAs) in adults and children. Information from non-clinical and clinical trials with oral brepocitinib was leveraged to set safety thresholds. This combined approach was used to inform future dose-strength selection and treated BSA limits.

RESULTS

Data from 256 patients were analyzed. Patient type, dose strength, and frequency had significant impacts on the dose-exposure relationship. Systemic concentration in patients with PsO was predicted to be 45% lower than in patients with AD from the same dose. When topically applied to the same percentage BSA, brepocitinib systemic exposures are expected to be comparable between adults and children. The systemic steady-state exposure after 3% once daily and twice daily (2 mg/cm2) cream applied to less than 50% BSA in patients with AD and PsO, respectively, maintains at least a threefold margin to non-clinical safety findings and clinical hematologic markers.

CONCLUSION

The relationship between the amount of active drug applied and brepocitinib systemic CTrough, described by LMER, may inform the development strategy for dose optimization in the brepocitinib topical program.

Characterization of Different Inflammatory Skin Conditions in a Mouse Model of DNCB-Induced Atopic Dermatitis

The mouse model of 2,4-dinitrochlorbenzene (DNCB)-induced human-like atopic dermatitis (hlAD) has been widely used to test novel treatment strategies and compounds. However, the study designs and methods are highly diverse, presenting different hlAD disease patterns that occur after sensitization and repeated challenge with DNCB on dorsal skin. In addition, there is a lack of information about the progression of the disease during the experiment and the achieved pheno- and endotypes, especially at the timepoint when therapeutic treatment is initiated. We here examine hlAD in a DNCB-induced BALB/cJRj model at different timepoints: (i) before starting treatment with dexamethasone, representing a standard drug control (day 12) and (ii) at the end of the experiment (day 22). Both timepoints display typical AD-associated characteristics: skin thickening, spongiosis, hyper- and parakeratosis, altered cytokine and gene expression, increased lipid mediator formation, barrier protein and antimicrobial peptide abnormalities, as well as lymphoid organ hypertrophy. Increased mast cell infiltration into the skin and elevated immunoglobulin E plasma concentrations indicate a type I allergy response. The DNCB-treated skin showed an extrinsic moderate sub-acute hlAD lesion at day 12 and an extrinsic mild sub-acute to chronic pheno- and endotype at day 22 with a dominating Th2 response. A dependency of the filaggrin formation and expression in correlation to the disease severity in the DNCB-treated skin was found. In conclusion, our study reveals a detailed classification of a hlAD at two timepoints with different inflammatory skin conditions and pheno- and endotypes, thereby providing a better understanding of the DNCB-induced hlAD model in BALB/cJRj mice.

Metabolic re-programming of keratinocytes in response to contact allergens

BACKGROUND

Allergic contact dermatitis (ACD) is a common skin disease caused by the recognition of haptens by the immune system. Keratinocytes play an important role in the initiation and facilitation of inflammatory responses in ACD. Immune responses are associated with major changes in metabolism. However, metabolic re-programming is not well studied in ACD; specifically, knowledge of metabolic alterations in structural cells is lacking.

METHODS

Metabolic re-programming in ACD was studied using publicly available transcriptome datasets. Primary pooled keratinocytes and a keratinocyte cell line (HaCaT) were stimulated with contact allergens, and inflammatory responses and expression of metabolic markers were measured by qPCR and flow cytometry, respectively.

RESULTS

ACD is characterized by metabolic re-programming with a metabolic profile similar to atopic dermatitis. Exposure to contact allergens causes a wide array of metabolic alterations. Stimulation of keratinocytes with contact allergens induced inflammatory responses typical for ACD and was associated with an up-regulation of proteins representative for glucose uptake, fatty acid metabolism, oxidative phosphorylation and to some extent arginine biosynthesis. Changes in these metabolic pathways were also observed when comparing lesional with non-lesional contact dermatitis skin.

CONCLUSIONS

ACD is, similarly to other inflammatory skin diseases, characterized by metabolic re-programming. Contact allergen exposure induces expression of a wide array of metabolic pathways, which is at least in part mediated through metabolic re-programming of keratinocytes.

Comparison of metabolic and neurological comorbidities in Asian patients with psoriasis and atopic dermatitis

Although various comorbidities have been noted to be associated with atopic dermatitis (AD) and psoriasis, few studies have compared comorbidities between the two diseases, and little is known about whether these comorbidities vary by the subtypes of psoriasis. In this study of 1:1 age- and sex-matched pair analysis between patients diagnosed with either psoriasis or AD at Asan Medical Center between 1991 and 2020, comorbidities, as determined by the International Classification of Diseases-10 codes, and likelihood ratios of metabolic and neurologic comorbidities in psoriasis compared with AD were studied using a logistic regression model. Among a total of 14,128 patients, the psoriasis group had higher odds of obesity (odds ratio [95% confidence interval]: 1.49 [1.34-1.66]), hypertension (1.14 [1.03-1.26]), diabetes mellitus (1.46 [1.29-1.66]), chronic kidney disease (1.59 [1.22-2.08]), and Parkinson's disease (2.1 [1.15-3.83]) than the AD group. Subgroup analysis revealed that patients with plaque psoriasis had higher odds of obesity (1.18 [1.05-1.33]), hypertension (1.18 [1.06-1.32]), diabetes mellitus (1.53 [1.34-1.75]), chronic kidney disease (1.66 [1.26-2.17]), and Parkinson's disease (2.12 [1.16-3.88]) compared with AD. Meanwhile, guttate psoriasis was associated with higher odds of dementia (3.63 [1.06-12.40]) and patients with generalized pustular psoriasis showed higher odds of diabetes mellitus (5.42 [1.56-18.83]) compared with AD. In conclusion, Asian patients with all types of psoriasis should be closely monitored for the development of metabolic and neurologic diseases, especially men and those aged ≥ 40 years.

Diversity of atopic dermatitis and selection of immune targets

Atopic dermatitis (AD) is a heterogeneous immune-mediated skin disorder affecting people of all ages and ethnicities. Despite the development of targeted therapeutics such as biologics and Janus kinase inhibitors, attaining complete clinical efficacy remains difficult. This therapeutic challenge may be attributed to the complex pathogenesis of AD. Although the TH2 axis has been extensively studied, recent advancements have started to reveal the involvement of additional immune pathways including TH1, TH17, and TH22. Understanding the interplay of these immune axes may contribute to a more personalized therapeutic approach based on patients' molecular profile, with the prospect of improving clinical outcome. This review will discuss studies exploring the molecular profile of AD in both skin and blood across age, ethnicity/race, disease chronicity, IgE levels, filaggrin mutation status, and AD association with other atopic conditions. Moreover, it will explore the potential of personalized treatment strategies based on a patient's distinct immune signature.

Anti-Inflammatory Effect of Fermented Cabbage Extract Containing Nitric Oxide Metabolites with Silica

The aim of this study was to evaluate the anti-inflammatory effect of fermented cabbage extract (FC) containing nitric oxide metabolites with silica (FCS) on 1-fluoro-2,4-dinitrofluorobenzene (DNFB)-induced atopic dermatitis (AD) in BALB/c mice. Atopic dermatitis-like allergic contact dermatitis was induced by DNFB challenge in the ear after DNFB sensitization on the dorsal skin of mice. FCS alleviated the severity of atopic dermatitis-like skin lesions. In addition, epidermis thickness of the ear and penetration of inflammatory cells in atopic dermatitis-like skin lesions were decreased after topical application of FCS. The serum levels of TNF-α and IL-4 were measured in atopic dermatitis mice using ELISA kits, which were observed to be significantly decreased after topical application of FCS. This study demonstrates that the FCS can be used as a potential therapeutic for the treatment and prevention of AD.

Genomic Profiling of the Overlap Phenotype between Psoriasis and Atopic Dermatitis

Clinical overlaps between psoriasis and atopic dermatitis (AD) are sometimes undiscernible, and there is no consensus on whether to treat the overlap phenotype as psoriasis or AD. We enrolled 41 patients diagnosed with either psoriasis or AD and clinically re-stratified them into classic psoriasis (n = 11), classic AD (n = 13), and the overlap phenotype between psoriasis and AD (n = 17). We compared the gene expression profiles of lesional and nonlesional skin biopsy tissues and the proteomic profiles of blood samples among the three comparison groups. Global mRNA expression and T-cell subset cytokine expression in the skin and protein biomarker elevation in the blood of the overlap phenotype were consistent with the profiles of psoriasis and different from the profiles of AD. Unsupervised k-means clustering indicated that the best number of distinct clusters for the total population of the three comparison groups was two, and the two clusters of psoriasis and AD were differentiated by gene expression. Our study suggests that the clinical overlap phenotype between psoriasis and AD has dominant molecular features of psoriasis, and genomic biomarkers can differentiate psoriasis and AD at molecular levels in patients with a spectrum of psoriasis and AD.

Exosomes derived from human dermal fibroblasts (HDFn-Ex) alleviate DNCB-induced atopic dermatitis (AD) via PPARα

Atopic dermatitis (AD) is a chronic inflammatory skin disease. Skin barrier dysfunction is the initial step in the development of AD. Recently, exosomes have been considered as potential cell-free medicine for skin defects such as aging, psoriasis and wounds. The aim of this study was to investigate the effects of human dermal fibroblast-neonatal-derived exosome (HDFn-Ex) on AD. HDFn-Ex increased the expression of peroxisome proliferator activated receptor α (PPARα) and alleviated the 1-chloro-2,4-dinitrobenzene (DNCB)-mediated downregulation of filaggrin, involucrin, loricrin, hyaluronic acid synthase 1 (HAS1) and HAS2 in human keratinocyte HaCaT cells. However, these effects were inhibited by the PPARα antagonist GW6471. In the artificial skin model, HDFn-Ex significantly inhibited DNCB-induced epidermal hyperplasia and the decrease in filaggrin and HAS1 levels via a PPARα. In the DNCB-induced AD-like mouse model, HDFn-Ex administration reduced epidermis thickening and mast cell infiltration into the dermis compared to DNCB treatment. Moreover, the decreases in PPARα, filaggrin and HAS1 expression, as well as the increases in IgE and IL4 levels induced by DNCB treatment were reversed by HDFn-Ex. These effects were blocked by pre-treatment with GW6471. Furthermore, HDFn-Ex exhibited an anti-inflammatory effect by inhibiting the DNCB-induced increases in IκBα phosphorylation and TNF-α expression. Collectively, HDFn-Ex exhibited a protective effect on AD. Notably, these effects were regulated by PPARα. Based on our results, we suggest that HDFn-Ex is a potential candidate for treating AD by recovering skin barrier dysfunction and exhibiting anti-inflammatory activity.

ΔNp63 Regulates Homeostasis, Stemness, and Suppression of Inflammation in the Adult Epidermis

The p63 transcription factor is critical for epidermis formation in embryonic development, but its role in the adult epidermis is poorly understood. In this study, we show that acute genetic ablation of ΔNp63, the main p63 isoform, in adult epidermis disrupts keratinocyte proliferation and self-maintenance and, unexpectedly, triggers an inflammatory psoriasis-like condition. Mechanistically, single-cell RNA sequencing revealed the downregulation of cell cycle genes, upregulation of differentiation markers, and induction of several proinflammatory pathways in ΔNp63-ablated keratinocytes. Intriguingly, ΔNp63-ablated cells disappear by 3 weeks after ablation, at the expense of the remaining nonablated cells. This is not associated with active cell death and is likely due to reduced self-maintenance and enhanced differentiation. Indeed, in vivo wound healing, a physiological readout of the epidermal stem cell function, is severely impaired upon ΔNp63 ablation. We found that the Wnt signaling pathway (Wnt10A, Fzd6, Fzd10) and the activator protein 1 (JunB, Fos, FosB) factors are the likely ΔNp63 effectors responsible for keratinocyte proliferation/stemness and suppression of differentiation, respectively, whereas IL-1a, IL-18, IL-24, and IL-36γ are the likely negative effectors responsible for suppression of inflammation. These data establish ΔNp63 as a critical node that coordinates epidermal homeostasis, stemness, and suppression of inflammation, upstream of known regulatory pathways.

The decoy oligodeoxynucleotide against HIF-1α and STAT5 ameliorates atopic dermatitis-like mouse model

Atopic dermatitis (AD) is a common inflammatory skin disease caused by an immune disorder. Mast cells are known to be activated and granulated to maintain an allergic reaction, including rhinitis, asthma, and AD. Although hypoxia-inducible factor-1 alpha (HIF-1α) and signal transducer and activator of transcription 5 (STAT5) play crucial roles in mast cell survival and granulation, their effects need to be clarified in allergic disorders. Thus, we designed decoy oligodeoxynucleotide (ODN) synthetic DNA, without open ends, containing complementary sequences for HIF-1α and STAT5 to suppress the transcriptional activities of HIF-1α and STAT5. In this study, we demonstrated the effects of HIF-1α/STAT5 ODN using AD-like in vivo and in vitro models. The HIF-1α/STAT5 decoy ODN significantly alleviated cutaneous symptoms similar to AD, including morphology changes, immune cell infiltration, skin barrier dysfunction, and inflammatory response. In the AD model, it also inhibited mast cell infiltration and degranulation in skin tissue. These results suggest that the HIF-1α/STAT5 decoy ODN ameliorates the AD-like disorder and immunoglobulin E (IgE)-induced mast cell activation by disrupting HIF-1α/STAT5 signaling pathways. Taken together, these findings suggest the possibility of HIF-1α/STAT5 as therapeutic targets and their decoy ODN as a potential therapeutic tool for AD.

Biofunctional Inorganic Layered Double Hydroxide Nanohybrid Enhances Immunotherapeutic Effect on Atopic Dermatitis Treatment

Atopic dermatitis (AD) is a widespread, recurrent, and chronic inflammatory skin condition that imposes a major burden on patients. Conventional treatments, such as corticosteroids, are associated with various side effects, underscoring the need for innovative therapeutic approaches. In this study, the possibility of using indole-3-acetic acid-loaded layered double hydroxides (IAA-LDHs) is evaluated as a novel treatment for AD. IAA is an auxin-class plant hormone with antioxidant and anti-inflammatory effects. Following the synthesis of IAA-LDH nanohybrids, their ability to induce M2-like macrophage polarization in macrophages obtained from mouse bone marrow is assessed. The antioxidant activity of IAA-LDH is quantified by assessing the decrease in intracellular reactive oxygen species levels. The anti-inflammatory and anti-atopic characteristics of IAA-LDH are evaluated in a mouse model of AD by examining the cutaneous tissues, immunological organs, and cells. The findings suggest that IAA-LDH has great therapeutic potential as a candidate for AD treatment based on its in vitro and in vivo modulation of AD immunology, enhancement of macrophage polarization, and antioxidant activity. This inorganic drug delivery technology represents a promising new avenue for the development of safe and effective AD treatments.

Non-invasive biochemical analysis and comparison of atopic dermatitis and psoriasis skin using handheld confocal Raman spectroscopy

A handheld non-invasive confocal Raman system (CRS) was used to evaluate the differences in skin biochemicals between atopic dermatitis (AD) and psoriasis, which are inflammatory skin conditions. Raman spectral measurements in the fingerprint and high wavenumber region were acquired using a portable in-house CRS system with excitation lasers operating at 671 and 785 nm. It was deduced that relative amount of water decreases in the following sequence of skin: healthy, psoriasis and AD. Moreover, differential trends were observed for the subclasses of ceramides such that ceramide 3 is lower in the lesional AD and psoriasis skin as compared to healthy, while ceramide 2 showed a contrasting trend of decrease in lesional AD and increase in lesional psoriasis as opposed to healthy skin. Amount of cholesterol was significantly higher in lesional psoriasis as compared to lesional AD and healthy skin. These differences can aid in an objective classification of the skin conditions and in the formulation of new disease-specific topical treatments.

MRGPRX2, drug pseudoallergies, inflammatory diseases, mechanisms and distinguishing MRGPRX2- and IgE/FcεRI-mediated events

MRGPRX2, a novel Gaq -coupled human mast cell receptor, mediates non-immune adverse reactions without the involvement of antibody priming. Constitutively expressed by human skin mast cells, MRGPRX2 modulates cell degranulation producing pseudoallergies manifesting as itch, inflammation and pain. The term pseudoallergy is defined in relation to adverse drug reactions in general and immune/non-immune-mediated reactions in particular. A list of drugs with MRGPRX2 activity is presented, including a detailed examination of three important and widely used approved therapies: neuromuscular blockers, quinolones and opioids. For the clinician, the significance of MRGPRX2 is considered as an aid in distinguishing and ultimately identifying specific immune and non-immune inflammatory reactions. Anaphylactoid/anaphylactic reactions, neurogenic inflammation and inflammatory diseases with a clear or strongly suspected association with MRGPRX2 activation are examined. Inflammatory diseases include chronic urticaria, rosacea, atopic dermatitis, allergic contact dermatitis, mastocytosis, allergic asthma, ulcerative colitis and rheumatoid arthritis. MRGPRX2- and allergic IgE/FcεRI-mediated reactions may be clinically similar. Importantly, the usual testing procedures do not distinguish the two mechanisms. Currently, identification of MRGPRX2 activation and diagnosis of pseudoallergic reactions is generally viewed as a process of exclusion once other non-immune and immune processes, particularly IgE/FcεRI-mediated degranulation of mast cells, are ruled out. This does not take into account that MRGPRX2 signals via β-arrestin, which can be utilized to detect MRGPRX2 activation by employing MRGPRX2 transfected cells to assess MRGPRX2 activation via two pathways, the G-protein-independent β-arrestin pathway and the G-protein-dependent Ca2+ pathway. Testing procedures, interpretations for distinguishing mechanisms, patient diagnosis, agonist identification and drug safety evaluations are addressed.

Single-nuclei RNA-seq reveals skin cell responses to Aeromonas hydrophila infection in Chinese longsnout catfish Leiocassis longirostris

As the primary natural barrier that protects against adverse environmental conditions, the skin plays a crucial role in the innate immune response of fish, particularly in relation to bacterial infections. However, due to the diverse functionality and intricate anatomical and cellular composition of the skin, deciphering the immune response of the host is a challenging task. In this study, single nuclei RNA-sequencing (snRNA-seq) was performed on skin biopsies obtained from Chinese longsnout catfish (Leiocassis longirostris), comparing Aeromonas hydrophila-infected subjects to healthy control subjects. A total of 19,581 single nuclei cells were sequenced using 10x Genomics (10,400 in the control group and 9,181 in the treated group). Based on expressed unique transcriptional profiles, 33 cell clusters were identified and classified into 12 cell types including keratinocyte (KC), fibroblast (FB), endothelial cells (EC), secretory cells (SC), immune cells, smooth muscle cells (SMC), and other cells such as pericyte (PC), brush cell (BC), red blood cell (RBC), neuroendocrine cell (NDC), neuron cells (NC), and melanocyte (MC). Among these, three clusters of KCs, namely, KC1, KC2, and KC5 exhibited significant expansion after A. hydrophila infection. Analysis of pathway enrichment revealed that KC1 was primarily involved in environmental signal transduction, KC2 was primarily involved in endocrine function, and KC5 was primarily involved in metabolism. Finally, our findings suggest that neutrophils may play a crucial role in combating A. hydrophila infections. In summary, this study not only provides the first detailed comprehensive map of all cell types present in the skin of teleost fish but also sheds light on the immune response mechanism of the skin following A. hydrophila infection in Chinese longsnout catfish.

Phytochemical Investigation of Equisetum arvense and Evaluation of Their Anti-Inflammatory Potential in TNFα/INFγ-Stimulated Keratinocytes

Equisetum arvense L. (Equisetaceae), widely known as 'horsetail', is a perennial plant found extensively across Asia. Extracts of E. arvense have been used in traditional medicine, particularly for the treatment of inflammatory disorders. This study aimed to determine the phytochemical compounds in E. arvense ethanolic extract and their anti-inflammatory properties. Subsequently, we isolated and identified nine secondary metabolites, including kaempferol 3,7-di-O-β-D-glucopyranoside (1), icariside B2 (2), (Z)-3-hexenyl β-D-glucopyranoside (3), luteolin 5-O-β-D-glucopyranoside (4), 4-O-β-D-glucopyranosyl caffeic acid (5), clemastanin B (6), 4-O-caffeoylshikimic acid (7), (7S,8S)-threo-7,9,9'-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan-4-O-β-D-glucopyranoside (8), and 3-O-caffeoylshikimic acid (9). The chemical structures of the isolated compounds (1-9) were elucidated using HR-ESI-MS data, NMR spectra, and ECD data. Next, the anti-inflammatory effects of the isolates were evaluated in tumor necrosis factor (TNF)α/interferon (IFN)γ-induced HaCaT, a human keratinocyte cell line. Among the isolates, compound 3 showed the highest inhibitory effect on the expression of pro-inflammatory chemokines, followed by compounds 6 and 8. Correspondingly, the preceding isolates inhibited TNFα/IFNγ-induced activation of pro-inflammatory transcription factors, signal transducer and activator of transcription 1, and nuclear factor-κB. Collectively, E. arvense could be employed for the development of prophylactic or therapeutic agents for improving dermatitis.

IL-22 as a target for therapeutic intervention: Current knowledge on its role in various diseases

IL-22 has emerged as a crucial cytokine mediating protective response against pathogens and tissue regeneration. Dysregulated production of IL-22 has been shown to play a pivotal role in the pathogenesis of various diseases like malignant tumours, viral, cardiovascular, allergic and autoimmune disorders. Interleukin 22 belongs to IFN-IL-10 cytokine family. It is a major proinflammatory cytokine secreted by activated Th1 cells (Th22), though can also be secreted by many other immune cells like group 3 innate lymphocytes, γδ T cells, NK cells, NK T cells, and mucosal associated invariant T cells. Th22 cells exclusively release IL-22 but not IL-17 or IFN-γ (as Th1 cells releases IFN-γ along with IL-22 and Th17 cells releases IL-17 along with IL-22) and also express aryl hydrocarbon receptor as the key transcription factor. Th22 cells also exhibit expression of chemokine receptor CCR6 and skin-homing receptors CCR4 and CCR10 indicating the involvement of this subset in bolstering epithelial barrier immunity and promoting secretion of antimicrobial peptides (AMPs) from intestinal epithelial cells. The function of IL-22 is modulated by IL-22 binding protein (binds to IL-22 and inhibits it binding to its cell surface receptor); which serves as a competitor for IL-22R1 chain of IL-22 receptor. The pathogenic and protective nature of the Th22 cells is modulated both by the site of infected tissue and the type of disease pathology. This review aims to discuss key features of IL-22 biology, comparisons between IL and 22 and IFN-γ and its role as a potential immune therapy target in different maladies.

Assessment of Treatment-Relevant Immune Biomarkers in Psoriasis and Atopic Dermatitis: Toward Personalized Medicine in Dermatology

Immunologically targeted therapies have revolutionized the treatment of inflammatory dermatoses, including atopic dermatitis and psoriasis. Although immunologic biomarkers hold great promise for personalized classification of skin disease and tailored therapy selection, there are no approved or widely used approaches for this in dermatology. This review summarizes the translational immunologic approaches to measuring treatment-relevant biomarkers in inflammatory skin conditions. Tape strip profiling, microneedle-based biomarker patches, molecular profiling from epidermal curettage, RNA in situ hybridization tissue staining, and single-cell RNA sequencing have been described. We discuss the advantages and limitations of each and open questions for the future of personalized medicine in inflammatory skin disease.

Establishment and Characterization of Mild Atopic Dermatitis in the DNCB-Induced Mouse Model

In dermatological research, 2,4-dinitrochlorbenzene (DNCB)-induced atopic dermatitis (AD) is a standard model as it displays many disease-associated characteristics of human AD. However, the reproducibility of the model is challenging due to the lack of information regarding the methodology and the description of the phenotype and endotype of the mimicked disease. In this study, a DNCB-induced mouse model was established with a detailed procedure description and classification of the AD human-like skin type. The disease was induced with 1% DNCB in the sensitization phase and repeated applications of 0.3% and 0.5% DNCB in the challenging phase which led to a mild phenotype of AD eczema. Pathophysiological changes of the dorsal skin were measured: thickening of the epidermis and dermis, altered skin barrier proteins, increased TH1 and TH2 cytokine expression, a shift in polyunsaturated fatty acids, increased pro-resolving and inflammatory mediator formation, and dysregulated inflammation-associated gene expression. A link to type I allergy reactions was evaluated by increased mast cell infiltration into the skin accompanied by elevated IgE and histamine levels in plasma. As expected for mild AD, no systemic inflammation was observed. In conclusion, this experimental setup demonstrates many features of a mild human-like extrinsic AD in murine skin.

Genome-wide DNA methylation and transcription analysis in psoriatic epidermis

Aim: To identify DNA methylation and transcription biomarkers in the psoriatic epidermis. Materials & methods: Gene transcription and DNA methylation datasets of psoriatic epidermal tissue were obtained from the Gene Expression Omnibus. Machine learning algorithm analysis and weighted gene coexpression network analysis were carried out to screen hub genes. Results: Differentially methylated and expressed genes were identified in the psoriatic epidermis. Six hub genes were selected - GZMB, CRIP1, S100A12, ISG15, CRABP2 and VNN1 - whose transcript levels showed a significant correlation with Psoriasis Area and Severity Index scores and immune infiltration. Conclusion: Psoriatic epidermis is primarily in a hypermethylated status. Epidermis-specific hub differentially methylated and expressed genes are potential biomarkers to help judge the condition of psoriasis.

Clinical translation of anti-inflammatory effects of Prevotella histicola in Th1, Th2, and Th17 inflammation

Introduction

EDP1815 is a non-colonizing pharmaceutical preparation of a single stain of Prevotella histicola isolated from the duodenum of a human donor. We report here preclinical and clinical studies showing that the action of EDP1815, an orally delivered and gut restricted single strain of commensal bacteria can regulate inflammatory responses throughout the body.

Methods

Supported by evidence for anti-inflammatory activity in three preclinical mouse models of Th1-, TH2-, and Th17-mediated inflammation, EDP1815 was tested clinically in three Phase 1b studies in patients with psoriasis, patients with atopic dermatitis, and healthy volunteers in a KLH skin challenge model.

Results

Preclinically, EDP1815 was efficacious in all three mouse models of inflammation, showing reduction in skin inflammation as well as related tissue cytokines. In the Phase 1b studies, EDP1815 was found to be well tolerated by participants, with a safety profile comparable to placebo, including no severe or consistent side-effects reported, and no evidence of immunosuppression with no opportunistic infection occurring in these studies. In psoriasis patients, signs of clinical efficacy were seen after 4 weeks of treatment, which continued beyond the treatment period in the higher-dose cohort. In atopic dermatitis patients, improvements were seen throughout the key physician-and patient-reported outcomes. In a healthy-volunteer study of a KLH-induced skin inflammatory response, consistent anti-inflammatory effects were seen in two cohorts through imaging-based measures of skin inflammation.

Discussion

This is the first report demonstrating clinical effects from targeting peripheral inflammation with a non-colonizing gut-restricted single strain of commensal bacteria, providing proof of concept for a new class of medicines. These clinical effects occur without systemic exposure of EDP1815 or modification of the resident gut microbiota, and with placebo-like safety and tolerability. The breadth of these clinical effects of EDP1815, combined with its excellent safety and tolerability profile and oral administration, suggests the potential for a new type of effective, safe, oral, and accessible anti-inflammatory medicine to treat the wide range of diseases driven by inflammation.Clinical Trial Registration: EudraCT # 2018-002807-32; EudraCT # 2018-002807-32; NL8676; https://clinicaltrials.gov/ct2/show/NCT03733353; http://www.trialregister.nl.

Mongolian medicine Wenguanmu ointment treats eczema by inhibiting the CKLF-1/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The main clinical manifestations of eczema include itching, erythema, swelling and pain. Currently, allergies and TH1/TH2 cytokine imbalances are significant causes of eczema. TCM believes that eczema is mainly caused by incongruity between dry and wet. Wenguanmu ointment is a classic Mongolian medicine, which mainly composed of Xanthoceras sorbifolia Bunge, Coptis chinensis Franch and Bezoar. These ingredients can clear heat and dampness, dispel wind and dehumidification, anti-inflammatoryad analgesic. In this study, it was found that Wenguanmu ointment can treat eczema with anti-inflammatory, analgesic and antipruritic.

AIM OF THE STUDY

In this study, the content of main components in Wenguanmu ointment was tested. Moreover, the therapeutic effect and mechanism of Wenguanmu ointment on eczema model mice were studied.

MATERIALS AND METHODS

Kunming mice (25 ± 2 g) were randomly divided into 6 groups: Control group; Model group; Vehicle group; Wenguanmu ointment group; Compound dexamethasone acetate cream group; Chushizhiyang ointment group. The eczema mouse model was established by DNCB. HPLC and TLC tests were used to determine the content of the main components in Wenguanmu ointment. HE staining was used to assess skin damage in mice. In order to detect the anti-inflammatory effect of Wenguanmu ointment on eczema, The levels of IgE, TNF-α, IFN-γ, COX-2 and IL-4 in serum was measured by ELISA. Genecards and Online Mendelian Inheritance in Man databases were used to analyze potential target gene predictions, and it was speculated that Wenguanmu ointment was associated with NF-κB signaling pathway and chemokine signaling pathway. To detect this inference, RT-qPCR and western blotting were used to detect protein and mRNA levels of CKLF-1, IκB-α, and NF-κB.

RESULTS

Wenguanmu ointment can repress the symptoms of eczema caused by 2, 4-dinitrochlorobenzene, and inhibit the level of serum immunoglobulin E. Simultaneously it restrain the elevation of miscellaneous pro-inflammatory cytokines and chemokines, as well as reducing the expression of CKLF-1 and NF-κB protein in the nucleus, and increasing the protein expression of IκB to improve eczema.

CONCLUSIONS

The ameliorating effect of Wenguanmu ointment on eczema lesions can play a importment role by inhibiting the CKLF-1/NF-κB pathway.

The translational revolution in atopic dermatitis: the paradigm shift from pathogenesis to treatment

Atopic dermatitis (AD) is the most common inflammatory skin disease, and it is considered a complex and heterogeneous condition. Different phenotypes of AD, defined according to the patient age at onset, race, and ethnic background; disease duration; and other disease characteristics, have been recently described, underlying the need for a personalized treatment approach. Recent advancements in understanding AD pathogenesis resulted in a real translational revolution and led to the exponential expansion of the therapeutic pipeline. The study of biomarkers in clinical studies of emerging treatments is helping clarify the role of each cytokine and immune pathway in AD and will allow addressing the unique immune fingerprints of each AD subset. Personalized medicine will be the ultimate goal of this targeted translational research. In this review, we discuss the changes in the concepts of both the pathogenesis of and treatment approach to AD, highlight the scientific rationale behind each targeted treatment and report the most recent clinical efficacy data.

Paradoxical Reactions to Anti-TNFα and Anti-IL-17 Treatment in Psoriasis Patients: Are Skin and/or Gut Microbiota Involved?

Psoriasis is a chronic, immune-mediated, inflammatory disease primarily affecting the skin. It is currently coming to light that patients with psoriasis have disrupted intestinal barrier and often suffer from comorbidities associated with the gastrointestinal tract. Moreover, there is growing evidence of both cutaneous and intestinal paradoxical reactions during biologic treatment in patients with psoriasis. This review focuses on barrier defects and changes in immune responses in patients with psoriasis, which play an important role in the development of the disease but are also influenced by modern biological treatments targeting IL-17 and TNFα cytokines. Here, we highlight the relationship between the gut-skin axis, microbiota, psoriasis treatment, and the incidence of paradoxical reactions, such as inflammatory bowel disease in patients with psoriasis. A better understanding of the interconnection of these mechanisms could lead to a more personalized therapy and lower the incidence of treatment side effects, thereby improving the quality of life of the affected patients.

Dipotassium Glycyrrhizininate Improves Skin Wound Healing by Modulating Inflammatory Process

Wound healing is characterized by a systemic and complex process of cellular and molecular activities. Dipotassium Glycyrrhizinate (DPG), a side product derived from glycyrrhizic acid, has several biological effects, such as being antiallergic, antioxidant, antibacterial, antiviral, gastroprotective, antitumoral, and anti-inflammatory. This study aimed to evaluate the anti-inflammatory effect of topical DPG on the healing of cutaneous wounds by secondary intention in an in vivo experimental model. Twenty-four male Wistar rats were used in the experiment, and were randomly divided into six groups of four. Circular excisions were performed and topically treated for 14 days after wound induction. Macroscopic and histopathological analyses were performed. Gene expression was evaluated by real-time qPCR. Our results showed that treatment with DPG caused a decrease in the inflammatory exudate as well as an absence of active hyperemia. Increases in granulation tissue, tissue reepithelization, and total collagen were also observed. Furthermore, DPG treatment reduced the expression of pro-inflammatory cytokines (Tnf-α, Cox-2, Il-8, Irak-2, Nf-kB, and Il-1) while increasing the expression of Il-10, demonstrating anti-inflammatory effects across all three treatment periods. Based on our results, we conclude that DPG attenuates the inflammatory process by promoting skin wound healing through the modulation of distinct mechanisms and signaling pathways, including anti-inflammatory ones. This involves modulation of the expression of pro- and anti-inflammatory cytokine expression; promotion of new granulation tissue; angiogenesis; and tissue re-epithelialization, all of which contribute to tissue remodeling.

Dietary Intake and Systemic Inflammation: Can We Use Food as Medicine?

PURPOSE OF REVIEW

This review summarizes the current literature regarding the association between diet and systemic inflammation.

RECENT FINDINGS

Data in humans suggests that consumption of plant-based nutrients is associated with a reduction in systemic inflammation, while consumption of red meat and excessive dairy has the opposite effect and may increase risk of acute flares in those that suffer from certain chronic diseases like inflammatory bowel disease or psoriasis and certain cancers. There is a known association between diet and systemic inflammation; thus, we recommend that clinicians discuss plant-based, whole food diets with patients, particularly those that suffer from chronic inflammatory diseases as an adjunct treatment for these conditions. Future research should evaluate whether adherence to these types of diets is sustainable in the long term and how these changes affect important quality of life concerns.

miRNA expression profiles of the perilesional skin of atopic dermatitis and psoriasis patients are highly similar

Atopic dermatitis (AD) and psoriasis vulgaris (PV) are chronic inflammatory skin diseases with heterogeneous molecular backgrounds. MicroRNAs (miRNAs) contribute to either development or regulation of many immune system related diseases. Only few miRNA profiling studies are available for AD and no comparisons between AD and PV skin miRNA profiles have been performed recently. We conducted a miRNA profiling analysis of skin, as well as serum, from adult AD and PV patients and control individuals. 130 miRNAs were differentially expressed in AD skin, of which 77 were common differentially expressed in AD and PV. No differentially expressed miRNAs were detected in serum. Pathway analyses revealed differentially expressed miRNAs to potentially target immune-system related pathways, including TNF-α, IL-2/STAT4 and IL-6/JAK/STAT3. Additional genetic analysis of published AD GWAS dataset detected association of several target genes of differentially expressed miRNAs in skin. Moreover, miR-28-5p, miR-31-5p, miR-378a-3p and miR-203a were validated as upregulated in the skin of AD and PV patients. All validated miRNAs were reliable predictive markers for AD or PV. In conclusion, miRNA expression pattern in the skin of adult AD patients is highly similar to that of PV with multiple differentially expressed miRNAs potentially involved in the regulation of immune responses in AD and PV.

Combined application of dinitrofluorobenzene and ovalbumin induced AD-like dermatitis with an increase in helper T-cell cytokines and a prolonged Th2 response

BACKGROUND

The progression of acute-to-chronic atopic dermatitis is accompanied by multiple helper T-cell cytokine responses, but the mechanisms and relative importance of these changes remain unclear. There is no animal model for atopic dermatitis that recapitulates these cytokine responses.

OBJECTIVE

We sought to build a novel mouse model for atopic dermatitis (AD) that recapitulates these helper T-cell responses and some dynamic changes in cytokine responses in the progression of AD.

METHODS

Female BALB/c mice were subjected to the application of dinitrofluorobenzene (DNFB) and ovalbumin (OVA) to induce AD-like dermatitis. Skin lesions and serum were collected from mice in the acute and chronic phases to detect changes in cytokine responses and other features of AD.

RESULTS

Combined application of DNFB and OVA successfully induced AD-like dermatitis and histological changes as well as epidermal barrier dysfunction. In the acute phase of AD-like dermatitis, Th2-associated cytokines were mainly increased in serum and skin lesions. In the chronic phase of AD-like dermatitis, Th2-associated cytokines were still highly expressed, while Th1- and Th17-associated cytokines were also gradually increased. Compared with the acute phase, the JAK-STAT signaling pathway was highly expressed in the chronic phase of AD-like dermatitis.

CONCLUSION

The combined application of DNFB and OVA could be used to build a new mouse model for atopic dermatitis. This mouse model recapitulates the helper T-cell responses and some dynamic changes in cytokine responses in the progression of acute-to-chronic in human AD. The JAK-STAT signaling pathway plays a pivotal role in the chronicity of AD.

Advanced thermal sensing techniques for characterizing the physical properties of skin

Measurements of the thermal properties of the skin can serve as the basis for a noninvasive, quantitative characterization of dermatological health and physiological status. Applications range from the detection of subtle spatiotemporal changes in skin temperature associated with thermoregulatory processes, to the evaluation of depth-dependent compositional properties and hydration levels, to the assessment of various features of microvascular/macrovascular blood flow. Examples of recent advances for performing such measurements include thin, skin-interfaced systems that enable continuous, real-time monitoring of the intrinsic thermal properties of the skin beyond its superficial layers, with a path to reliable, inexpensive instruments that offer potential for widespread use as diagnostic tools in clinical settings or in the home. This paper reviews the foundational aspects of the latest thermal sensing techniques with applicability to the skin, summarizes the various devices that exploit these concepts, and provides an overview of specific areas of application in the context of skin health. A concluding section presents an outlook on the challenges and prospects for research in this field.

Aruncus dioicus var. kamtschaticus Extract Ameliorates Psoriasis-like Skin Inflammation via Akt/mTOR and JAK2/STAT3 Signaling Pathways in a Murine Model

Goat's beard (Aruncus dioicus var. kamtschaticus) is a traditional medicinal plant, widely used in Chinese and Korean traditional medicine because of its anti-inflammatory, anti-oxidant, antimicrobial, and anti-cancer activity. However, its effect on skin inflammatory diseases like psoriasis is unknown. The aim of this study was to investigate the therapeutic potency of A. dioicus extract (ADE) in in vitro and in vivo psoriasis models. ADE treatment significantly attenuated skin inflammation and improved skin integrity in imiquimod-treated mice by suppressing keratinocyte hyperproliferation, inhibiting the infiltration of immune cells, and downregulating the expression of psoriatic markers. Further, ADE treatment suppressed protein kinase B/mammalian target of rapamycin (Akt/mTOR) and Janus kinase 2/signal transducers and activators of transcription 3 (JAK2/STAT3) signaling in HaCaT cells. Overall, the application of ADE relieves psoriasis-like skin inflammation possibly by regulating the Akt/mTOR and JAK2/STAT3 signaling pathways, making it an effective alternative for psoriasis therapy.

Ameliorative Effects of Daphnopsis costaricensis Extract against Oxazolone-Induced Atopic Dermatitis-like Lesions in BALB/c Mice

The genus Daphnopsis has been traditionally used as a purgative, diuretic, stimulant, and psoriasis treatment. In this study, the anti-AD (atopic dermatitis) activities of the Daphnopsis costaricensis EtOH extract (DCE) were investigated in an oxazolone (OX)-induced mouse model of AD, and the anti-inflammatory effects of its active compounds were confirmed in PI-sensitized or IgE/DNP-BSA-sensitized RBL-2H3 cells. DCE improved the symptoms of OX-induced inflammatory dermatitis (swelling, erythema, and increased ear thickening) in OX-induced BALB/c mice ears and reduced epidermal thickness and mast cell infiltration. Eleven flavonoid compounds were isolated from DCE, and two compounds (7,8-dimethoxyflavone and 7,2'-dimethoxyflavone) significantly inhibited IL-4 overexpression in PI-induced RBL-2H3 cells and mast cell degranulation in IgE + DNP-BSA-induced RBL-2H3 cells. Our study indicates that DCE and two compounds (7,8-dimethoxyflavone and 7,2'-dimethoxyflavone) might effectively improve inflammatory and atopic skin symptoms.

IL-17D-induced inhibition of DDX5 expression in keratinocytes amplifies IL-36R-mediated skin inflammation

Aberrant RNA splicing in keratinocytes drives inflammatory skin disorders. In the present study, we found that the RNA helicase DDX5 was downregulated in keratinocytes from the inflammatory skin lesions in patients with atopic dermatitis and psoriasis, and that mice with keratinocyte-specific deletion of Ddx5 (Ddx5^∆KC) were more susceptible to cutaneous inflammation. Inhibition of DDX5 expression in keratinocytes was induced by the cytokine interleukin (IL)-17D through activation of the CD93-p38 MAPK-AKT-SMAD2/3 signaling pathway and led to pre-messenger RNA splicing events that favored the production of membrane-bound, intact IL-36 receptor (IL-36R) at the expense of soluble IL-36R (sIL-36R) and to the selective amplification of IL-36R-mediated inflammatory responses and cutaneous inflammation. Restoration of sIL-36R in Ddx5^∆KC mice with experimental atopic dermatitis or psoriasis suppressed skin inflammation and alleviated the disease phenotypes. These findings indicate that IL-17D modulation of DDX5 expression controls inflammation in keratinocytes during inflammatory skin diseases.

The IL-4/-13 Axis and Its Blocking in the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a common inflammatory skin disease with a complex pathophysiology, intertwining immune dysregulation, epidermal barrier dysfunction, IgE sensitization, environmental factors and genetic predisposition. It has been recently identified that interleukins -4 and -13 play crucial roles in the type-2-driven inflammation that characterizes AD, contributing to its symptomatology. Novel therapeutic approaches that target Th2 cytokines and their respective pathways have been developed, aiming to optimize the treatment of AD.

Cell death in skin function, inflammation, and disease

Cell death is an essential process that plays a vital role in restoring and maintaining skin homeostasis. It supports recovery from acute injury and infection and regulates barrier function and immunity. Cell death can also provoke inflammatory responses. Loss of cell membrane integrity with lytic forms of cell death can incite inflammation due to the uncontrolled release of cell contents. Excessive or poorly regulated cell death is increasingly recognised as contributing to cutaneous inflammation. Therefore, drugs that inhibit cell death could be used therapeutically to treat certain inflammatory skin diseases. Programmes to develop such inhibitors are already underway. In this review, we outline the mechanisms of skin-associated cell death programmes; apoptosis, necroptosis, pyroptosis, NETosis, and the epidermal terminal differentiation programme, cornification. We discuss the evidence for their role in skin inflammation and disease and discuss therapeutic opportunities for targeting the cell death machinery.

Unveiling the true costs and societal impacts of moderate-to-severe atopic dermatitis in Europe

Atopic dermatitis (AD) is a chronic, auto-immune condition that imposes a high burden on individuals, society, and the healthcare system. Approximately 4.4% of adults and up to 18.6% of children/adolescents have AD in Europe, with 20% of all cases accounting for moderate-to-severe forms. This form of the condition in adults results in annual societal costs across Europe of an estimated €30 billion; €15.2 billion related to missed workdays or reduced work productivity, €10.1 billion related to direct medical costs and €4.7 billion related to personal expenditure of patients/families. AD can also substantially impact physical, emotional, and social quality-of-life. Several studies have shown the debilitating itch-scratch cycle is the main cause of the multifaceted burden, as it causes substantial sleep deprivation and stigmatisation due to the physical appearance of the skin, and confidence issues. These factors lead to psychosocial issues and can cumulate over time and prohibit patients reaching their 'full life potential'. Despite this, many patients with the condition are undertreated, resulting in uncontrolled symptoms and a further strain placed on patients, society, and the economy. The authors of this White Paper comprise the European Atopic Dermatitis Working Group, which is a network of international specialists with expertise in dermatology and healthcare policy decisions. Their programme of action is focused on harnessing their expertise to build consensus, advance research, share knowledge, and ultimately seek to improve AD care outcomes through achieving long-term symptom control. This White Paper presents a systematic evaluation of the overall financial and humanistic burden of moderate-to-severe AD and the current challenges that exist with AD care. It introduces recommendations for how, collaboratively, key stakeholders and policy makers can support improvements in AD management to achieve better disease control, thus reducing the costs and associated burden placed on individuals, society, and the economy.

Identification of key apoptosis-related genes and immune infiltration in the pathogenesis of psoriasis

Background

Psoriasis is a condition in which skin cells build up and form itchy scales and dry patches. It is also considered a common lifelong disease with an unclear pathogenesis. Furthermore, an effective cure for psoriasis is still unavailable. Reductive apoptosis of keratinocytes and immune infiltration are common in psoriasis. This study aimed to explore underlying functions of key apoptosis-related genes and the characteristics of immune infiltration in psoriasis. We used GSE13355 and GSE30999 to screen differentially expressed apoptosis related genes (DEARGs) in our study. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and gene set enrichment analysis (GSEA) were performed using clusterProfiler package. Protein–protein interaction (PPI) network was constructed to acquire key DEARGs. Transcription factor (TF)–target and miRNA–mRNA network analyses, drug sensitivity prediction, and immune infiltration were applied. Key DEARGs were validated using real-time quantitative PCR (RT-qPCR).

Results

We identified 482 and 32 DEARGs from GSE13355 and GSE30999, respectively. GO analysis showed that DEARGs were commonly enriched in cell chemotaxis, receptor ligand activity, and signaling receptor activator activity. KEGG pathway analysis indicated that viral protein interaction with cytokine and cytokine receptor was maximally enriched pathway. The GSEA analysis of GSE13355 and GSE30999 demonstrated a high consistency degree of enriched pathways. Thirteen key DEARGs with upregulation were obtained in the PPI network. Eleven key DEARGs were confirmed using RT-qPCR. Additionally, 5 TFs and 553 miRNAs were acquired, and three novel drugs were predicted. Moreover, Dendritic.cells.activated exhibited high levels of immune infiltration while Mast.cells.resting showed low levels of immune infiltration in psoriasis groups.

Conclusion

Results of this study may reveal some insights into the underlying molecular mechanism of psoriasis and provide novel targeted drugs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41065-022-00233-0.

Maternal diet during pregnancy and risk of allergic diseases in children up to 7-9 years old from Polish Mother and Child Cohort study

BACKGROUND

The impact of maternal diet during pregnancy on the risk of allergic diseases in childhood is an increasing scientific and public health concern. We evaluated the associations of maternal type of diet and essential elements and vitamins intake during pregnancy with offspring allergic and respiratory outcomes.

METHODS

The study population included 557 mother-child pairs from Polish Mother and Child Cohort (REPRO_PL). Based on the Food Frequency Questionnaire filled in between the 20th-24th week of pregnancy, overall maternal diet was evaluated as the difference between the Prudent Dietary Pattern (PDP) score and Western Dietary Pattern (WDP) score ((PDP-WDP) score) and maternal achievement of dietary recommendations (estimated average requirement, EAR) for essential elements and vitamins was assessed. Children's health examination at age of 1, 2, and 7-9 years covered the following symptoms: infections, wheezing/asthma, food allergy, allergic rhinitis, and atopic dermatitis. At age of 7-9 years, children underwent spirometry and skin-prick tests.

RESULTS

Children of the mothers who were not achieving adequate intake of vitamin C during pregnancy had a higher risk of wheezing and having more than two infections within the first two years of life comparing to those who met EAR (OR = 2.6, p = 0.05, and OR = 2.3, p = 0.04, respectively). Inadequate intake of vitamin E during pregnancy was related to a higher risk of atopic dermatitis (OR = 2.7, p = 0.04), whereas inadequate intake of magnesium during pregnancy was associated with the risk of wheezing in the offspring at age of two years (OR = 3.7, p = 0.03). A lower (PDP-WDP) score during pregnancy (indicating unhealthier diet) was associated with a higher risk of infections (OR = 1.5, p = 0.007) but a lower risk of atopic dermatitis (OR = 0.7, p = 0.02) at age of 7-9 years.

CONCLUSIONS

These results may contribute to the body of evidence for the impact of maternal diet during pregnancy for children's optimal health, however further studies are needed before drawing conclusions and recommendations for clinical practice.

Immunotherapy using Histobulin™ in psoriasis: A case report

There is no cure for psoriasis. A psoriasis patient was treated with Histobulin™. The patient's clinical symptoms and signs disappeared after the eighth injection and did not recur for more than 18 months. Histobulin™ was effective in the treatment of psoriasis and is suggested as a curative therapeutic for psoriasis.

There is no cure for psoriasis, and early treatment is recommended to improve skin manifestations and systemic inflammation, which can lead to comorbidities in various organs. Histobulin™ was effective and induced remission in a psoriasis patient.

Thioredoxin-interacting protein regulates keratinocyte differentiation: Implication of its role in psoriasis

Thioredoxin-interacting protein (TXNIP), also known as Vitamin-D upregulated protein-1 (VDUP-1), interacts with thioredoxin to regulate redox responses and participates in diverse disorders including metabolic, cardiovascular, inflammatory and malignant diseases. Psoriasis is characterized by chronic skin inflammation and an aberrant pattern of keratinocyte differentiation. Clinically, psoriasis is associated with various cardiometabolic comorbidities but studies on TXNIP's biological role in skin disorders are limited. In this study, we investigated TXNIP expression in psoriasis and its regulation in normal human epidermal keratinocytes (NHEKs), and then explored how TXNIP regulated skin keratinocyte differentiation to determine its role in psoriasis pathogenesis. Our immunohistochemical study demonstrated extensive TXNIP expression in the upper and lower epidermis of psoriasis compared to predominant TXNIP expression in the basal layer of normal skin. 1, 25-dihydroxyvitamin D₃  suppressed but TGF-α and EGF enhanced TXNIP expression in NHEKs. An inducer of keratinocyte differentiation, phorbol 12-myristate 13-acetate (PMA), also diminished TXNIP expression, which was reversed by PKC-δ knockdown. TXNIP knockdown reduced PMA-induced involucrin and transglutaminse-1 expression, and increased p63 expression in NHEKs but did not significantly affect cell proliferation. H₂ O₂ -induced ROS production and EGFR phosphorylation decreased in NHEKs with TXNIP knockdown. Furthermore, PMA-induced PKC-δ phosphorylation, TGF-α, and EGF-triggered EGFR phosphorylation were attenuated by TXNIP knockdown. Our results unraveled the regulation and function of TXNIP expression in skin keratinocytes and the cross-regulation between TXNIP and EGFR signaling. These findings imply a role of TXNIP in psoriasis and provide insight into the possible impact of TXNIP regulators on the skin or psoriasis.

Extract from Black Soybean Cultivar A63 Extract Ameliorates Atopic Dermatitis-like Skin Inflammation in an Oxazolone-Induced Murine Model

Black soybean has been used in traditional medicine to treat inflammatory diseases, cancer, and diabetes and as a nutritional source since ancient times. We found that Korean black soybean cultivar A63 has more cyanidin-3-O-glucoside, (C3G), procyanidin B2 (PB2), and epicatechin (EPC) contents than other cultivars and has beneficial effects on cell viability and anti-oxidation. Given the higher concentration of anthocyanidins and their strong anti-oxidant activity, we predicted that A63 extract could relieve inflammatory disease symptoms, including those of atopic dermatitis (AD). Here, we evaluated the anti-AD activity of A63 extract in an oxazolone (OXA)-induced mouse model. A63 extract treatment significantly reduced epidermal thickness and inflammatory cell infiltration, downregulated the expression of AD gene markers, including Interleukin (IL)-4 and IL-5, and restored damaged skin barrier tissues. Furthermore, A63 extract influenced the activation of the signal transducer and activator of transcription (STAT) 3 and STAT6, extracellular regulatory kinase (ERK), and c-Jun N-terminal kinase (JNK) signaling pathways, which play a crucial role in the development of AD. Altogether, our results suggest that A63 can ameliorate AD-like skin inflammation by inhibiting inflammatory cytokine production and STAT3/6 and Mitogen-activated protein kinase (MAPK) signaling and restoring skin barrier function.

Integrated bioinformatic analysis of gene expression profiling data to identify combinatorial biomarkers in inflammatory skin disease

Selection of appropriate biomarker to identify inflammatory skin diseases is complicated by the involvement of thousands of differentially expressed genes (DEGs) across multiple cell types and organs. This study aimed to identify combinatorial biomarkers in inflammatory skin diseases. From one gene expression microarray profiling dataset, we performed bioinformatic analyses on dataset from lesional skin biopsies of patients with inflammatory skin diseases (atopic dermatitis [AD], contact eczema [KE], lichen planus [Li], psoriasis vulgaris [Pso]) and healthy controls to identify the involved pathways, predict upstream regulators, and potential measurable extracellular biomarkers. Overall, 434, 629, 581, and 738 DEGs were mapped in AD, KE, Li, and Pso, respectively; 238 identified DEGs were shared among four different inflammatory skin diseases. Bioinformatic analysis on four inflammatory skin diseases showed significant activation of pathways with known pathogenic relevance. Common upstream regulators, with upregulated predicted activity, identified were CNR1 and BMP4. We found the following common serum biomarkers: ACR, APOE, ASIP, CRISP1, DKK1, IL12B, IL9, MANF, MDK, NRTN, PCSK5, and VEGFC. Considerable differences of gene expression changes, involved pathways, upstream regulators, and biomarkers were found in different inflammatory skin diseases. Integrated bioinformatic analysis identified 12 potential common biomarkers of inflammatory skin diseases requiring further evaluation.

Gut dysbiosis in cutaneous T-cell lymphoma is characterized by shifts in relative abundances of specific bacterial taxa and decreased diversity in more advanced disease

BACKGROUND

Cutaneous T-cell lymphoma (CTCL) patients often suffer from recurrent skin infections and profound immune dysregulation in advanced disease. The gut microbiome has been recognized to influence cancers and cutaneous conditions; however, it has not yet been studied in CTCL.

OBJECTIVES

To investigate the gut microbiome in patients with CTCL and in healthy controls.

METHODS

Case-control study conducted between January 2019 and November 2020 at Northwestern's busy multidisciplinary CTCL clinic (Chicago, Illinois, USA) utilizing 16S ribosomal RNA gene amplicon sequencing and bioinformatics analyses to characterize the microbiota present in fecal samples of CTCL patients (n=38) and age-matched healthy controls (n=13) from the same geographical region.

RESULTS

Gut microbial α-diversity trended lower in patients with CTCL and was significantly lower in patients with advanced CTCL relative to controls (p=0.015). No differences in β-diversity were identified. Specific taxa were significantly reduced in patient samples; significance was determined using adjusted p-values (q-values) that accounted for a false discovery rate threshold of 0.05. Significantly reduced taxa in patient samples included the phylum Actinobacteria (q=0.0002), classes Coriobacteriia (q=0.002) and Actinobacteria (q=0.03), order Coriobacteriales (q=0.003), and genus Anaerotruncus (q=0.01). The families of Eggerthellaceae (q=0.0007) and Lactobacillaceae (q=0.02) were significantly reduced in patients with high skin disease burden.

CONCLUSIONS

Gut dysbiosis can be seen in patients with CTCL compared to healthy controls and is pronounced in more advanced CTCL. The taxonomic shifts associated with CTCL are similar to those previously reported in atopic dermatitis and opposite those of psoriasis, suggesting microbial parallels to the immune profile and skin barrier differences between these conditions. These findings may suggest new microbial disease biomarkers and reveal a new angle for intervention.