From Emollients to Biologicals: Targeting Atopic Dermatitis

Eblasakimab, an Anti-IL‑13Rα1 Antibody, Reduces Atopy-Associated Serum Biomarkers in Moderate‑to‑Severe Atopic Dermatitis

INTRODUCTION

Eblasakimab, a first-in-class monoclonal antibody with a unique mechanism to target the interleukin (IL)-13 receptor alpha 1 (IL-13Rα1), inhibits IL-4/IL-13 signaling in the pathophysiology of atopic dermatitis (AD). This study investigates the impact of eblasakimab on type 2 inflammatory biomarkers in patients with moderate-to-severe AD.

METHODS

A double‑blind, multiple ascending dose, phase Ib study evaluated the effect of eblasakimab (200, 400, 600 mg) or placebo administered subcutaneously once weekly for 8 weeks in patients with moderate‑to‑severe AD. Serum levels of thymus and activation-regulated chemokine (TARC), total immunoglobulin E (IgE), and lactate dehydrogenase (LDH) were assessed.

RESULTS

Eblasakimab suppressed TARC, IgE, and LDH in the 400-mg and 600-mg groups over 8 weeks of treatment. Patients in the 400-mg and 600-mg groups experienced a reduction of 72.8% (p = 0.004) and 62.9% (p = 0.003), respectively, for TARC, 35.1% (p = 0.006) and 20.9% (not significant; NS), respectively, for IgE, and 24.6% (NS) and 23.1% (NS), respectively, for LDH between baseline and Week 8. Reduction in serum TARC in the 400-mg group was significantly greater than placebo as early as Week 1, whereas reductions in total IgE were more gradual. Serum TARC and total IgE remained suppressed in the 400-mg and 600-mg eblasakimab groups for 4-6 weeks following the last administered dose.

CONCLUSION

The effect of eblasakimab on circulating AD‑associated biomarker levels was accompanied by improvements in signs and symptoms of AD, consistent with the inhibition of IL-13 and IL-4 signaling via the type 2 receptor.

TRIAL REGISTRATION NUMBER

NCT04090229.

The NLRP3 inflammasome in allergic diseases: mechanisms and therapeutic implications

In recent years, there has been a global increase in the prevalence of allergic diseases, including allergic rhinitis, chronic rhinosinusitis, allergic asthma, atopic dermatitis, allergic conjunctivitis, and food allergies. Since the pathogenic mechanisms of these allergic diseases are not yet fully understood, targeted and effective therapies are lacking. The NLRP3 inflammasome, a multiprotein complex implicated in various inflammatory diseases, can be activated by diverse stimuli. It assembles into NLRP3 inflammasome complexes through conformational changes, initiating the proteolytic cleavage of dormant procaspase-1 into active caspase-1 and promoting the maturation of inflammatory cytokines, including IL-1β and IL-18. Dysfunction of the NLRP3 inflammasome may serve as a key driver of inflammatory diseases, leading to pyroptosis and amplifying the local inflammatory response. As preliminarily demonstrated, specific NLRP3 inflammatory vesicle inhibitors play refectory roles in animal models of allergic diseases, and it is believed that specific NLRP3 inflammasome inhibitors may be potential therapeutic agents for allergic diseases. This review highlights the progress of research on the NLRP3 inflammasome in allergic diseases, explores its contribution to different types of allergic diseases, and identifies promising clinical targets for intervention.

Efficacy and action mechanisms of compound Shen Chan decoction on experimental models of atopic dermatitis

Shen chan decoction (SCD) as a significant Traditional Chinese medicine (TCM) to treat atopic dermatitis (AD), but its mechanism of action has not been clarified, so we started the present study, first possible effects of SCD on AD were predicted using network pharmacology. Next, dinitrochlorobenzene was used to establish a mouse model of AD. After successful modelling, the SCD were administered intragastrically to treat the mice. Eventually, the KEGG pathway enrichment analysis indicated that SCD improved AD mainly through effects on inflammation and the gut microbiota. The experimental findings revealed that SCD treatment attenuated AD symptoms and downregulate the characteristic immune factors, namely IL-4, IL-6 and IgE. Moreover, it promoted a balance between Th1/Th2 cells. Furthermore, the itch signaling pathways involving H1R/PAR-2/TRPV1 were inhibited. The 16S rRNA sequencing results indicated that SCD administration influenced the Firmicutes/Bacteroidetes ratio at the phylum level by augmenting the relative proportions of Lactobacillaceae and Muribaculaceae at the family and genus levels, while decreasing the abundances of Lactococcus and Ruminococcus. These findings suggest that internal administration of SCD is an effective therapeutic approach for AD. We suggest that SCD may be an alternative therapy for the treatment of AD.Additionally, it could offer valuable insights into the pathogenesis of AD and the development of innovative therapeutic agents.

Quality of Care and Management of Atopic Dermatitis Across Different Levels of Healthcare-A Survey-Based Patient Experience

Atopic dermatitis (AD) is a chronic and fluctuating disease. Optimal management of AD and related comorbidities requires seamless coordination across multiple layers of the healthcare system. The objective of this survey was to explore patients' experiences with current management of AD. Out of 251 responders to this anonymous survey, 76% reported to have moderate or severe AD. Sixty-nine percent with moderate and 45% with severe AD were followed up at primary care level only. Use of advanced systemic treatment options was rare, and the majority experienced itch (97%), dry skin, rash, negative impact on self-esteem and comorbidities despite ongoing treatment. Only 36% received a treatment plan, more often in secondary (78.3%) than primary care (25.0%). Forty-three percent did not know who was responsible for their follow-up and 54% felt no one was responsible. Treatment options were commonly not known or understood. The survey results demonstrate undertreatment, lack of a holistic approach for management of AD. A national pathway including clear referral criteria and timelines can streamline management of AD across multiple levels of the healthcare system.

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.

N-benzyl-N-methyldecan-1-amine, derived from garlic, and its derivative alleviate 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin lesions in mice

Given the intricate etiology and pathogenesis of atopic dermatitis (AD), the complete cure of AD remains challenging. This study aimed to investigate if topically applying N-benzyl-N-methyldecan-1-amine (BMDA), derived from garlic, and its derivative [decyl-(4-methoxy-benzyl)-methyl-1-amine] (DMMA) could effectively alleviate AD-like skin lesions in 2,4-dinitrochlorobenzene (DNCB)-treated mice. Administering these compounds to the irritated skin of DNCB-treated mice significantly reduced swelling, rash, and excoriation severity, alongside a corresponding decrease in inflamed epidermis and dermis. Moreover, they inhibited spleen and lymph node enlargement and showed fewer infiltrated mast cells in the epidermis and dermis through toluidine-blue staining. Additionally, they led to a lower IgE titer in mouse sera as determined by ELISA, compared to vehicle treatment. Analyzing skin tissue from the mice revealed decreased transcript levels of inflammatory cytokines (TNF-α, IL-1β, and IL-6), IL-4, iNOS, and COX-2, compared to control mice. Simultaneously, the compounds impeded the activation of inflammation-related signaling molecules such as JNK, p38 MAPK, and NF-κB in the mouse skin. In summary, these findings suggest that BMDA and DMMA hold the potential to be developed as a novel treatment for healing inflammatory AD.

Jiawei guomin decoction regulates the degranulation of mast cells in atopic dermatitis mice via the HIS/PAR-2 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Guomin decoction (GMD) is a traditional Chinese medicine commonly used in clinical practice. It has traditionally been used to treat all allergic diseases. Currently, Jiawei Guomin Decoction (JWGMD) is used to treat sensitive skin after initial therapy. Although it has a significant clinical therapeutic effect, the exact role of mast cell degranulation in treating atopic dermatitis (AD) is still unclear.

AIM OF THE STUDY

GMD and JWGMD can both treat allergic diseases, while JWGMD focuses on skin allergies. This study aims to explore the potential effect of JWGMD on the degranulation of mast cells in an AD mouse model induced by 2,4-dinitrofluorobenzene (DNFB) and investigate the effectiveness of JWGMD in alleviating disease progression to further provide specific therapeutic targets for treating AD.

MATERIALS AND METHODS

The scratching times and skin lesions of model mice induced by DNFB were observed, and skin tissues were collected for subsequent measurement. Histopathological changes in the back skin of mice were observed by haematoxylin eosin (H&E) staining, Toluidine blue staining was used to detect the degranulation of mouse skin mast cells, and the relationship between the expression of histamine (HIS), mast cell tryptase (MCT) and mast cell degranulation was analysed by enzyme-linked immunosorbent assay (ELISA). The expression of protease-activated receptor-2 (PAR-2), histamine 1 receptor (H1R), H2R, H4R and MCT proteins in AD mice was detected by Western blot (WB). Immunofluorescence assay (IFA) further confirmed the localization of PAR-2, H1R, H2R, H4R, and MCT proteins in the skin. Quantitative real-time PCR (qPCR) was used to determine PAR-2, H1R, H2R and H4R mRNA levels in skin lesions to further clarify the mechanism by which JWGMD amplifies mast cell degranulation in AD. In addition, a reliable ultrahigh-performance liquid chromatography-quadrupole electrostatic field orbitrap mass spectrometry (UPLC-QE-MS) nontargeted metabolomics analysis was performed to analyse the differences in metabolite abundance between GMD and JWGMD, and these results were used to identify the active components in JWGMD that may have antipruritic and anti-inflammatory properties and inhibit mast cell degranulation.

RESULTS

After intermittent stimulation with DNFB, the skin lesions showed extensive desquamation, dryness, scabbing, skin thickening, and slight bleeding. Both treatments alleviated this phenomenon and reduced the number of scratches, with JWGMD being the most effective. JWGMD can significantly reduce inflammatory cell infiltration, oedema, and some capillary neogenesis in mice and reduce the degranulation of mast cells. The ELISA results showed that JWGMD can increase the levels of MCT and HIS proteins. The WB and IFA results demonstrated that JWGMD reduced the expression levels of PAR-2, H1R, H4R, and MCT proteins in skin lesions, with protein localization mainly in the epidermal layer, while H2R protein levels were increased and mainly localized in the dermis. In addition, JWGMD downregulates the mRNA expression of PAR-2, H1R, H2R, and H4R. Interestingly, through UPLC-QE-MS nontargeted metabolomic analysis, we detected the anti-inflammatory and antiallergy active substances in JWGMD, such as methyl eugenol, dictamnine and sinapine.

CONCLUSIONS

JWGMD may alleviate itching through methyl syringol, dictamnine, sinapine and other substances, and its mechanism may be related to inhibiting the HIS/PAR-2 pathway in AD model mice and further regulating the self-amplification of mast cell degranulation. JWGMD is a potential drug for treating AD. Therefore, it deserves continuous attention and research.

A Comprehensive Review of Phototherapy in Atopic Dermatitis: Mechanisms, Modalities, and Clinical Efficacy

This literature review explores atopic dermatitis and its management, with a focus on phototherapy as a treatment modality. The primary objectives are to elucidate the pathophysiological mechanisms, clinical manifestations, diagnostic criteria, and epidemiology of atopic dermatitis. Additionally, it seeks to explain phototherapy mechanisms, different modalities, and other therapeutic approaches. In this review, we comprehensively examine atopic dermatitis by synthesizing findings from diverse sources over the past 20 years. We investigate the epidemiology, pathophysiology, clinical manifestations, diagnostic criteria, and role of phototherapy in treatment. We conduct thematic analysis, compare phototherapy modalities, consider contextual factors, and integrate patient perspectives while upholding ethical considerations. Limitations include potential publication bias, language barriers, temporal constraints, subjectivity, and limited generalizability. Atopic dermatitis has a complex pathogenesis and can be managed with diverse modalities. Phototherapy emerges as an effective and safe treatment, particularly when other therapies prove ineffective.

Assessment and Management of Atopic Dermatitis in Primary Care Settings: A Systematic Review

Atopic dermatitis is a complex, recurrent, chronic inflammatory skin condition. It frequently begins to manifest in early childhood and may last throughout adulthood. The need for clinical practice guidelines that are based on evidence is critical for efficient and secure care. Little is known about how primary care providers (PCPs) should handle pediatric and adult atopic dermatitis cases and whether they should follow national recommendations. Our systemic review aimed to examine management strategies for treating adult and pediatric (family) atopic dermatitis, including topical calcineurin inhibitors (TCIs), topical corticosteroids (TCS), skin emollients, oral antihistamines, and diet. Data sources were PubMed (MEDLINE) and Embase. Our review investigated English-language articles from 2014 to 2023 that studied the management of adult and children atopic dermatitis. Overall, there were 15 articles included. Surveys and analyses of national databases were the most widely used methods (n=7). The use of TCS by PCPs was common, but they also overprescribed nonsedating antihistamines, favored low-potency drugs, and avoided TCIs. Most studies relied on healthcare personnel reporting their typical behaviors rather than looking at specific patient encounters and it is considered a limitation. Finally, there are gaps in knowledge and management of critical topics such as prescribing TCIs and understanding the safety profiles of TCS, when it comes to treating adult and pediatric atopic dermatitis. Future research in this area is urgently needed because the current systemic assessment is mostly restricted to small studies that assess prescribing behaviors with scant information describing nonmedication management.

A single-center, randomized, controlled study on the efficacy of niacinamide-containing body emollients combined with cleansing gel in the treatment of mild atopic dermatitis

OBJECTIVE

To observe the effect of niacinamide-containing body emollients combined with a cleansing gel on the clinical symptoms of mild atopic dermatitis (AD) in adults.

METHODS

From July 2022 to January 2023, adults with mild AD were enrolled at Huashan Hospital Affiliated to Fudan University using single-center, randomized and placebo-controlled methods. They were divided into three groups: the control group, treatment group 1 (T1) receiving niacinamide-containing body emollients alone, and treatment group 2 (T2) receiving emollients plus niacinamide-containing cleansing gel. All patients were orally administered 10 mg of ebastine tablets daily. AD severity (SCORAD score), peak pruritus numeric rating scale (PP-NRS), patient-oriented measure of eczema (POEM), dermatological quality of life index (DLQI) score, transepidermal water loss (TEWL), and stratum corneum water content (SCWC) were measured by the same dermatologist at days 0, 7, 14, and 28.

RESULTS

A total of 122 patients were enrolled, including 38 in the control group, 42 in the T1 group and 42 in the T2 group. There were no obvious adverse reactions at the end of the study and the clinical scores and stratum corneum barrier of all the groups improved significantly relative to baseline. The SCORAD, PP-NRS, DLQI, TEWL and SCWC scores in T1 group (12.43 ± 3, 3.3 ± 0.9, 7.1 ± 2.33, 17.1 ± 9.12, 67.2 ± 21.46, seperately) and T2 group (11.17 ± 3.26, 3 ± 1.3, 6.5 ± 2.11, 16.3 ± 9.12, 69.4 ± 24.52, seperately) were significantly improved than the control group(15.1 ± 3.64, 4.3 ± 1.7, 9.5 ± 2.46, 21.2 ± 9.47, 52.7 ± 22.43, seperately) at the endpoint of the study, while compared the POEM scores, only T2 group showed the difference with control group (5.2 ± 1.4 vs. 6 ± 1.6). The epidermal barrier parameters of TEWL and SCWC in the T2 group (17.57 ± 5.24, 66.46 ± 21.38, seperately) were significantly better than that of the T1 (19.96 ± 4.45, 56.45 ± 20.48, seperately) and control group(21.89 ± 7.03, 51.56 ± 16.58, seperately) on the 14th day of follow-up.

CONCLUSION

The use of niacinamide-containing body emollients can significantly improve the clinical symptoms, quality of life, and skin barrier function in patients with mild AD. The addition of niacinamide-containing cleansing gel can also affect the clinical efficacy at certain time points.

From gut to skin: exploring the potential of natural products targeting microorganisms for atopic dermatitis treatment

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease. Recent studies have revealed that interactions between pathogenic microorganisms, which have a tendency to parasitize the skin of AD patients, play a significant role in the progression of the disease. Furthermore, specific species of commensal bacteria in the human intestinal tract can have a profound impact on the immune system by promoting inflammation and pruritogenesis in AD, while also regulating adaptive immunity. Natural products (NPs) have emerged as promising agents for the treatment of various diseases. Consequently, there is growing interest in utilizing natural products as a novel therapeutic approach for managing AD, with a focus on modulating both skin and gut microbiota. In this review, we discuss the mechanisms and interplay between the skin and gut microbiota in relation to AD. Additionally, we provide a comprehensive overview of recent clinical and fundamental research on NPs targeting the skin and gut microbiota for AD treatment. We anticipate that our work will contribute to the future development of NPs and facilitate research on microbial mechanisms, based on the efficacy of NPs in treating AD.

Parnassin, a Novel Therapeutic Peptide, Alleviates Skin Lesions in a DNCB-Induced Atopic Dermatitis Mouse Model

Atopic dermatitis (AD) is a chronic inflammatory skin disease which requires continuous treatment due to its relapsing nature. The current treatment includes steroids and nonsteroidal agents targeting inflammation but long-term administration causes various side effects such as skin atrophy, hirsutism, hypertension and diarrhea. Thus, there is an unmet need for safer and effective therapeutic agents in the treatment of AD. Peptides are small biomolecule drugs which are highly potent and remarkably have less side effects. Parnassin is a tetrapeptide with predicted anti-microbial activity curated from Parnassius bremeri transcriptome data. In this study, we confirmed the effect of parnassin on AD using a DNCB-induced AD mouse model and TNF-α/IFN-γ-stimulated HaCaT cells. In the AD mouse model, topical administration of parnassin improved skin lesions and symptoms in AD mice, such as epidermal thickening and mast cell infiltration, similar to the existing treatment, dexamethasone, and did not affect body weight, or the size and weight of spleen. In TNF-α/IFN-γ-stimulated HaCaT cells, parnassin inhibited the expression of Th2-type chemokine CCL17 and CCL22 genes by suppressing JAK2 and p38 MAPK signaling kinases and their downstream transcription factor STAT1. Parnassin also significantly reduced the gene expression of TSLP and IL-31, which are pruritus-inducing cytokines. These findings suggested that parnassin alleviates AD-like lesions via its immunomodulatory effects and can be used as a candidate drug for the prevention and treatment of AD because it is safer than existing treatments.

Association of TLR2 and TLR9 gene polymorphisms with atopic dermatitis: a systematic review and meta-analysis with trial sequential analysis

Atopic dermatitis (AD) is a chronic, inflammatory skin disease. The mechanism was complex. Genetic mutations of Toll-like receptor (TLR) may be associated with AD, yet still unclear. We aim to provide specific evidence of the association of TLR2, TLR9 gene polymorphisms with AD. Publications were selected according to the criteria. Newcastle-Ottawa Scale was applied to evaluate the quality. The value of ORs and 95%CIs were applied to measure the associations. According to the heterogeneity, the effects model of fixed or random was selected in data combination. For TLR2 gene rs5743708 polymorphism, under allele and recessive contrasts, the pooled data showed a significant correlation, which was A vs a, OR = 0.51 (95%CI: 0.30, 0.86); AA vs Aa + aa, OR = 0.54 (95%CI: 0.33, 0.88). For TLR2 gene rs4696480 polymorphism, under allele, homozygous, heterozygous, and dominant contrasts, the pooled data showed a significant correlation, which was A vs a, OR = 0.79 (95%CI: 0.64, 0.97), AA vs aa, OR = 0.65 (95%CI: 0.43, 0.97), Aa vs aa, OR = 0.68 (95%CI: 0.48, 0.97), AA + Aa vs aa, OR = 0.67 (95%CI: 0.49, 0.93). There are significant associations of TLR2 gene rs5743708, rs4696480 polymorphisms with atopic dermatitis, while no associations are found in TLR9 gene rs5743836, rs187084 polymorphisms.

Molecular Mechanisms of Luteolin Against Atopic Dermatitis Based on Network Pharmacology and in vivo Experimental Validation

PURPOSE

To undercover the underlying mechanisms of luteolin against atopic dermatitis (AD), clinically characterized by recurrent eczematous lesions and intense itching, based on network pharmacology, molecular docking and in vivo experimental validation.

METHODS

TCMSP, STITCH and SwissTargetPrediction databases were utilized to screen the corresponding targets of luteolin. Targets related to AD were collected from DisGeNET, GeneCards and TTD databases. PPI network of intersection targets was constructed through STRING 11.0 database and Cytoscape 3.9.0 software. GO and KEGG enrichment analysis were performed to investigate the critical pathways of luteolin against AD. Further, the therapeutic effects and candidate targets/signaling pathways predicted from network pharmacology analysis were experimentally validated in a mouse model of AD induced by 2, 4-dinitrofluorobenzene (DNFB).

RESULTS

A total of 31 intersection targets were obtained by matching 151 targets of luteolin with 553 targets of AD. Among all, 20 core targets were identified by PPI network topology analysis, including IL-6, TNF, IL-10, VEGFA, IL-4, etc., and molecular docking indicated that luteolin binds strongly to these core targets. KEGG pathway enrichment analysis suggested that the intersected targets were significantly enriched in IL-17 signaling pathway, Th17 cell differentiation, Th1 and Th2 cell differentiation, JAK/STAT signaling pathway, etc. The in vivo experiment validated that luteolin could alleviate AD-like skin symptoms, as evidenced by the lower SCORAD score, the reduced infiltration of mast cells and the recovery of skin barrier function. Furthermore, luteolin restored immune balance by regulating the production of Th1/Th2/Th17-mediated cytokines, which were both the predicted core targets. Moreover, luteolin inhibited the phosphorylation of JAK2 and STAT3 in the lesional skin.

CONCLUSION

Together, the present study systematically clarifies the ameliorative effects and possible molecular mechanisms of luteolin against AD through the combination of network pharmacology and experimental validation, shedding light on the future development and clinical application of luteolin.

Functional Interplay between IL-9 and Peptide YY Contributes to Chronic Skin Inflammation

Complex interactions between keratinocytes and various cell types, such as inflammatory cells and stromal cells, contribute to the pathogenesis of chronic inflammatory skin lesions. In proinflammatory cytokine‒mediated disease settings, IL-9 plays a pathological role in inflammatory dermatitis. However, IL-9‒related mechanisms remain incompletely understood. In this study, we established tamoxifen-induced keratinocyte-specific IL-9RA-deficient mice (K14^CRE/ERTIl9ra^Δ/Δ mice) to examine the role of IL-9 in multicellular interactions under chronic skin inflammatory conditions. Studies using an imiquimod-induced psoriasis-like model showed that K14^CRE/ERTIl9ra^Δ/Δ mice exhibited a significantly reduced severity of dermatitis and mast cell infiltration compared with control K14^WTIl9ra^fl/fl mice. Transcriptome analyses of psoriasis-like lesions showed that the level of peptide Y-Y (Pyy), a member of the neuropeptide Y family, was markedly downregulated in K14^CRE/ERTIl9ra^Δ/Δ epidermis. Pyy blockade suppressed epidermal thickening and mast cell numbers in imiquimod-treated wild-type mice. Together with in vitro studies indicating that Pyy induced IL-9 production and chemotactic activity in bone marrow‒derived mast cells, these findings suggest that Pyy-mediated interplay between keratinocytes and mast cells contributes to psoriasiform inflammation. Further investigation focusing on the IL-9‒Pyy axis may provide valuable information for the development of new treatment modalities for inflammatory dermatitis.

Therapeutical Targets in Allergic Inflammation

From the discovery of IgE to the in-depth characterization of Th2 cells and ILC2, allergic inflammation has been extensively addressed to find potential therapeutical targets. To date, omalizumab, an anti-IgE monoclonal antibody, and dupilumab, an anti-IL-4 receptor α monoclonal antibody, represent two pillars of biologic therapy of allergic inflammation. Their increasing indications and long-term follow-up studies are shaping the many different faces of allergy. At the same time, their limitations are showing the intricate pathogenesis of allergic diseases.

Galactomyces Ferment Filtrate Potentiates an Anti-Inflammaging System in Keratinocytes

Skincare products play a crucial role in preventing the dry skin induced by various causes. Certain ingredients can help to improve the efficacy of skincare products. Galactomyces ferment filtrate (GFF) is such a functional ingredient. Its use originated from the empirical observation that the hands of sake brewers who deal with yeast fermentation retain a beautiful and youthful appearance. Consequently, skincare products based on GFF are widely used throughout the world. Recent studies have demonstrated that GFF activates an aryl hydrocarbon receptor (AHR) and upregulates the expression of filaggrin, a pivotal endogenous source of natural moisturizing factors, in epidermal keratinocytes. It also activates nuclear factor erythroid-2-related factor 2 (NRF2), the antioxidative master transcription factor, and exhibits potent antioxidative activity against oxidative stress induced by ultraviolet irradiation and proinflammatory cytokines, which also accelerate inflammaging. GFF-mediated NRF2 activation downregulates the expression of CDKN2A, which is known to be overexpressed in senescent keratinocytes. Moreover, GFF enhances epidermal terminal differentiation by upregulating the expression of caspase-14, claudin-1, and claudin-4. It also promotes the synthesis of the antiinflammatory cytokine IL-37 and downregulates the expression of proallergic cytokine IL-33 in keratinocytes. In addition, GFF downregulates the expression of the CXCL14 and IL6R genes, which are involved in inflammaging. These beneficial properties might underpin the potent barrier-protecting and anti-inflammaging effects of GFF-containing skin formulae.

Acne Vulgaris, Atopic Dermatitis and Rosacea: The Role of the Skin Microbiota-A Review

The skin harbors a huge number of different microorganisms such as bacteria, fungi and viruses, and it acts as a protective shield to prevent the invasion of pathogens and to maintain the health of the commensal microbiota. Several studies, in fact, have shown the importance of the skin microbiota for healthy skin. However, this balance can be altered by intrinsic and extrinsic factors, leading to the development of skin disease, such as acne vulgaris (AV), atopic dermatitis (AD) and rosacea(RS). Although these diseases are widespread and affect both adolescents and adults, the scientific correlation between these disorders and the skin microbiota and physiological parameters (TEWL, hydration and lipid composition) is still unclear. This review aims to investigate the current literature regarding the correlation between the skin microbiota and its imbalance underlying microbiological aspects, how the skin microbiota changes over the course of the disease and the current possible treatments. The following reported studies show a general imbalance of the bacterial flora. For this reason, more in-depth studies are necessary to explore the different subspecies and strains involved in all three diseases.

Food allergy, mechanisms, diagnosis and treatment: Innovation through a multi-targeted approach

The incidence of food allergy (FA) has continued to rise over the last several decades, posing significant burdens on health and quality of life. Significant strides into the advancement of FA diagnosis, prevention, and treatment have been made in recent years. In an effort to lower reliance on resource-intensive food challenges, the field has continued work toward the development of highly sensitive and specific assays capable of high-throughput analysis to assist in the diagnosis FA. In looking toward early infancy as a critical period in the development of allergy or acquisition of tolerance, evidence has increasingly suggested that early intervention via the early introduction of food allergens and maintenance of skin barrier function may decrease the risk of FA. As such, large-scale investigations are underway evaluating infant feeding and the impact of emollient and steroid use in infants with dry skin for the prevention of allergy. On the other end of the spectrum, the past few years have been witness to an explosive increase in clinical trials of novel and innovative therapeutic strategies aimed at the treatment of FA in those whom the disease has already manifested. A milestone in the field, 2020 marked the approval of the first drug, oral peanut allergen, for the indication of peanut allergy. With a foundation of promising data supporting the safety and efficacy of single- and multi-allergen oral immunotherapy, current efforts have turned toward the use of probiotics, biologic agents, and modified allergens to optimize and improve upon existing paradigms. Through these advancements, the field hopes to gain footing in the ongoing battle against FA.

Evaluation of the Anti-Atopic Dermatitis Effects of α-Boswellic Acid on Tnf-α/Ifn-γ-Stimulated HaCat Cells and DNCB-Induced BALB/c Mice

Boswellic acids, triterpenoids derived from the genus Boswellia (Burseraceae), are known for their anti-inflammatory and anti-tumor efficacy. Atopic dermatitis is a chronic, non-infectious inflammatory skin disease. However, the effects of α-boswellic acid on atopic dermatitis have not been studied. Therefore, in this study we examined the expression level of pro-inflammatory cytokines, histopathological analysis, and physiological data from BALB/c mice with atopic-like dermatitis induced by 2,4-dinitrochlorobenzene and TNF-α/IFN-γ-stimulated HaCaT cells to better understand the agent’s anti-atopic dermatitis efficacy. First, we found that α-boswellic reduced the epidermal thickening, mast cell numbers, and dermal infiltration of 2,4-dinitrochlorobenzene-induced atopic-like dermatitis in BALB/c mice. Furthermore, we also found that α-boswellic acid can restore transepidermal water loss and skin reddening in mice. In human keratinocytes inflamed by TNF-α/IFN-γ, α-boswellic acid inhibited MAP kinase activation and showed a reduction in NF-κB nuclear translocation. Finally, α-boswellic acid can reduce the expression level of cytokines (IL-1β, IL-6, and IL-8) following the stimulation of TNF-α/IFN-γ in HaCaT cells. Taken together, our study suggests that α-boswellic acids are a potential component for the development of anti-atopic dermatitis drugs.

Identification of Effective Diagnostic Biomarkers and Immune Cell Infiltration in Atopic Dermatitis by Comprehensive Bioinformatics Analysis

Background: Atopic dermatitis (AD) is a dermatological disorder characterized by symptoms such as chronically inflamed skin and frequently intolerable itching. The mechanism underlying AD development is still unclear. Our study aims to identify the diagnostic and therapeutic biomarkers for AD and provide insight into immune mechanisms at the molecular level through bioinformatics analysis.

Methods: The GSE6012, GSE32924, and GSE36842 gene expression profiles were obtained for analysis from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were segregated using the “Batch correction” and “RobustRankAggreg” methods. Weighted gene co-expression network analysis (WGCNA) was performed to screen for module genes with AD traits. Then, common DEGs (co-DEGs) were screened out via combined differential expression analysis and WGCNA. Functional enrichment analysis was performed for these co-DEGs using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG), followed by protein-protein interaction network analysis. Candidate hub genes were identified using the “cytoHubba” plugin in Cytoscape, and their value for AD diagnosis was validated using receiver operating characteristic curve analysis in the external database GSE120721. Immunohistochemical staining was performed for further validation. The CIBERSORT algorithm was used to evaluate skin samples obtained from healthy controls (HCs) and lesions of AD patients, to determine the extent of immune cell infiltration. The association between the identified hub genes and significant differential immune cells was analyzed using Pearson correlation analysis.

Results: A total of 259 DEGs were acquired from the intersection of DEGs obtained by the two independent procedures, and 331 AD-trait module genes were separated out from the blue module via WGCNA analysis. Then, 169 co-DEGs arising from the intersection of the 259 DEGs and the 331 AD-trait module genes were obtained. We found that co-DEGs were significantly enhanced in the type I interferon and IL-17 signal transduction pathways. Thirteen potential hub genes were identified using Cytoscape. Five hub genes (CCR7, CXCL10, IRF7, MMP1, and RRM2) were identified after screening via external dataset validation and immunohistochemical analysis. We also identified four significant differential immune cells, i.e., activated dendritic cells, plasma cells, resting mast cells, and CD4+ naïve T cells, between AD patients and HCs. Moreover, the relationship between the identified hub genes and significant differential immune cells was analyzed. The results showed that the CCR7 expression level was positively correlated with the number of CD4+ naïve T cells (R = 0.42, p = 0.011).

Conclusion: CCR7, CXCL10, IRF7, MMP1, and RRM2 could be potential diagnostic and therapeutic biomarkers for AD. CCR7 expression level was positively correlated with the number of CD4+ naïve T cells in AD. These findings need to be corroborated in future studies.