Th2 Cytokines and Atopic Dermatitis

Topical delivery of baricitinib-impregnated nanoemulgel: a promising platform for inhibition of JAK -STAT pathway for the effective management of atopic dermatitis

Baricitinib, an inhibitor of Janus kinase 1/2 receptors majorly involved in the dysregulation of immune responses in atopic dermatitis, is currently approved for managing atopic dermatitis in Europe. The delivery of baricitinib through oral route is associated to several adverse effects due to off-target effects. Therefore, the current study is aimed at formulation of baricitinib loaded nanoemulgel for evaluation of topical delivery potential in the treatment of atopic dermatitis. The baricitinib-loaded nanoemulsions (0.05 and 0.1% w/w) revealed an average globule size of 162.86 ± 0.37 and 173.66 ± 4.88 nm respectively with narrow PDI. The optimized batch of baricitinib nanoemulsion was converted to nanoemulgel by the addition of the mixture of gel bases SEPINEO™ DERM and SEPINEO™ P 600 along with propylene glycol, resulting in pseudoplastic shear thinning behaviour. The optimized nanoemulgels have shown prominent retention of baricitinib in the skin along with permeation. The skin distribution study of coumarin-6 loaded nanoemulgel demonstrated high fluorescence in the epidermal layer. The western blot analysis revealed significant inhibition of phosphorylated signal transducers and activators of transcriptions 1 (##p < 0.01) and 3 (#p < 0.05) by application of 0.05 and 0.1% baricitinib nanoemulgel. The baricitinib nanoemulgels have shown anti-inflammatory activity by significantly reducing expressions of various inflammatory markers. Histopathological analysis of skin tissues treated with baricitinib nanoemulgel has demonstrated a marked reduction in acanthosis, hyperkeratosis, and intact outer epidermis. These results supported the potential role of baricitinib-loaded nanoemulgel in reducing the inflammation and disease severity associated with atopic dermatitis.

Therapeutic potential of a systemically applied humanized monoclonal antibody targeting Toll‑like receptor 2 in atopic‑dermatitis‑like skin lesions in a mouse model

Atopic dermatitis (AD) is a prevalent, persistent inflammatory skin disorder distinguished by pruritic and irritated skin. Toll-like receptors (TLRs) are specialized receptors that recognize specific patterns associated with pathogens and tissue damage, triggering an innate immune response that protects the host from invading pathogens. Previously, it was demonstrated that intradermal injection of the humanized anti-TLR2 monoclonal antibody (Ab) Tomaralimab effectively relieved AD-like skin inflammation in BALB/c mouse models exposed to house dust mite extracts. However, it remains unclear whether allergenic hapten-induced AD can be effectively treated with systemically administered TLR2-targeting Abs. In the present study, it was observed that administrating Tomaralimab through intravenous injection alleviated AD-like skin lesions in BALB/c mice challenged with topical application of 2,4-dinitrochlorobenzene by reducing the infiltration of inflammatory cells into skin lesions and preventing the creation of various inflammatory cytokines, including thymic stromal lymphopoietin, interleukin (IL)-4, IL-13, IL-17 and IL-31, which are associated with the pathogenesis of AD. These findings support the feasibility of using a humanized anti-TLR2 monoclonal Ab as systemic therapy for AD.

Toll-like receptors in atopic dermatitis: pathogenesis and therapeutic implications

Toll-like receptors (TLR), the key players of the innate immune system, contribute to the pathogenesis of atopic dermatitis (AD) through multiple pathways. TLRs play a crucial role in delaying barrier repair, promoting Th2-mediated dermatitis, shifting the response toward Th1 in the chronic phase, and contributing to the establishment of the itch-scratch cycle, as well as mediating the effects of UV radiation. The dysregulation of proinflammatory and immunomodulatory effects of TLRs can be attributed to their ligand structures, receptor heterodimerization, the relative frequency of each TLR, interactions with other receptors/signalling pathways, cytokine milieu, and genetic polymorphisms. Current AD treatments like vitamin-D analogs, tacrolimus, and cyclosporine partially work through TLR modulation. Direct TLR stimulation using different compounds has shown therapeutic benefits in preclinical studies. However, significant challenges exist, including off-target effects due to ubiquitous TLR expression and complex roles in immune responses. Future directions include CRISPR-based gene editing to understand TLR functions, development of specific TLR modulators for targeted therapy, and machine learning applications to predict drug responses and identify novel ligands. Patient heterogeneity, including the presence or absence of polymorphisms, variations in TLR expression levels, and differences in immune responses, underscores the need for personalized therapeutic approaches.

Protective effect of Curcuma longa L. leaves and pseudostems extract against 1-chloro-2,4-dinitrobenzene-induced atopic dermatitis in BALB/c mice

ETHNOPHARMACOLOGICAL RELEVANCE

The perennial herbaceous plant, Curcuma longa L. (turmeric) is primarily grown and harvested for pharmacological purposes in China, Korea, and various tropical regions in South Asia. Turmeric has been used for centuries as an indigenous medicine. In particular, Ayurveda has been extensively used to treat, prevent, and manage multiple illnesses, including inflammation, allergies, arthritis, cancer, diabetes, diarrhea, psoriasis, and digestive issues. Importantly, various studies have confirmed the presence of numerous active compounds with health-enhancing biological properties in turmeric leaves and pseudostems.

AIM OF THE STUDY

Atopic dermatitis (AD) is a long-lasting inflammatory disorder that is associated with abnormalities in the immune system, such as T-helper (Th) cell dysregulation, elevated immunoglobulin (Ig) levels, inflammatory cell infiltration, and skin barrier damage. This study aimed to explore the therapeutic effects of turmeric leaves and pseudostems (CLHW) extract against AD in a BALB/c mouse disease model established using 1-chloro-2,4-dinitrobenzene (DNCB).

MATERIALS AND METHODS

AD-like symptoms were induced by topically applying DNCB to the dorsal skin of the mice, which were monitored over five weeks. Fourteen days after induction, the mice were randomly divided into different groups, and the treatment groups received daily oral gavage of CLHW for three weeks. Throughout the monitoring period, we assessed AD-like symptoms, including skin severity score, transepidermal water loss (TEWL), and scratching behavior of the mice. After measuring the body weight and ear thickness, the mice were euthanized. Furthermore, serum Ig and cytokine production levels were measured. Finally, the degrees of spleen and lymph node enlargement were evaluated, and the tissues were used for histopathological and molecular analyses.

RESULTS

CLHW improved AD-like symptoms, including skin severity score, TEWL, scratching frequency, and ear thickness in DNCB-induced AD mice. Additionally, serum levels of IgE, IgG1, and IgG2a, along with various inflammatory cytokines (interleukin [IL]-4, IL-5, and IL-13) and chemokines (Eotaxin and RANTES), were significantly reduced in CLHW-treated mice. CLHW decreased inflammatory cell infiltration and mast cell degranulation while downregulating mRNA expression levels of AD-related innate cytokines (thymic stromal lymphopoietin [TSLP], IL-25, IL-33), inflammatory cytokines (IL-4, IL-10, IL-13), and chemokines (thymus and activation-regulated chemokine [TARC], macrophage-derived chemokine [MDC]) in the dorsal skin. Furthermore, CLHW reduced spleen and lymph node enlargement and downregulated mRNA expression levels of inflammatory cytokines in these tissues in a dose-dependent manner.

CONCLUSION

The results demonstrated that CLHW can effectively suppress DNCB-induced AD-like symptoms by reducing the skin severity score, TEWL, scratching, ear thickness, serum Ig levels, inflammatory cell infiltration, and degranulation of mast cells, as well as the enlargement of the spleen and lymph nodes. Our findings highlight the ethnopharmacological potential of CLHW for treating abnormal immune responses associated with AD.

Beyond the dichotomy: understanding the overlap between atopic dermatitis and psoriasis

Atopic dermatitis and psoriasis have traditionally been considered distinct inflammatory skin diseases with unique pathogenic mechanisms. However, accumulating evidence suggests significant overlap in their immunological pathways, metabolic features, and microbiome characteristics, challenging this conventional dichotomy. This review comprehensively examines the complex relationship between psoriasis and atopic dermatitis, with particular emphasis on their shared and distinct pathogenic mechanisms. We analyze the immunological networks, metabolic pathways, and microbial factors contributing to their development and progression. The review expands upon the disease spectrum hypothesis and discusses the nomenclature for conditions exhibiting features of both diseases. We critically evaluate the clinical and histopathological characteristics of concomitant psoriasis and atopic dermatitis, highlighting recent advances in molecular diagnostics for accurate disease differentiation. Importantly, we propose standardized diagnostic criteria for psoriasis dermatitis and examine current therapeutic strategies for managing overlapping conditions. Recent developments in targeted therapies and their implications for treatment selection are thoroughly discussed. By synthesizing current evidence and identifying knowledge gaps, this review provides insights into the complex interplay between psoriasis and atopic dermatitis, aiming to guide clinical decision-making and future research directions in this evolving field.

Canthaxanthin ameliorates atopic dermatitis in mice by suppressing Th2 immune response

Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disorder characterized by intense pruritus and complex immunopathogenic mechanisms. Recent evidence has highlighted the critical link between dysregulated intestinal microecology and altered immune responses in AD progression. As essential components of the intestinal microenvironment, metabolites play pivotal roles in various physiological processes. Through metabolomic profiling in an AD mouse model, we identified a significant reduction in canthaxanthin (CTX), a bacterial-derived metabolite naturally present in many foods, in AD mice compared to healthy controls. To investigate the therapeutic potential of CTX, we established an AD model by repeatedly applying 2,4-dinitrochlorobenzene (DNCB) to the ears and dorsal skin of mice, successfully inducing AD-like symptoms and lesions. Notably, oral administration of CTX significantly attenuated skin inflammation and reduced serum IgE levels in this DNCB-induced AD model. Both in vivo and in vitro studies demonstrated that CTX treatment effectively suppressed Th2 immune responses. Mechanistically, we found that CTX significantly inhibited the activation of the JAK2-STAT6 signaling pathway in Th2-polarized T cells. Our findings not only demonstrate the therapeutic efficacy of CTX in AD but also elucidate its molecular mechanism in modulating T helper cell subset balance. These insights suggest that CTX could serve as a promising therapeutic agent for AD and potentially other Th2 response-mediated immune disorders.

Investigating the efficacy of gliclazide encapsulated hydrogel in the preclinical mice model for atopic dermatitis

Atopic dermatitis (AD) is a chronic skin inflammatory ailment commonly observed in young children and adults. Various therapeutic modalities are already explored for mitigation of AD but for prolong application very few modalities are recommended. Considering these challenges, we have successfully developed gliclazide-loaded hydrogels using the physical dispersion method. For preclinical assessment, we developed a DNCB induced an AD-like phenotype in mice, characterized by increased dermatitis index, scratching interval, ear thickness and weight, spleen and lymph node enlargement, mast cell infiltration, and elevated oxidative stress. However, topical application of the GLZ hydrogel significantly improved these DNCB-induced symptoms. Mice treated with the GLZ hydrogel exhibited a marked reduction in inflammatory markers in histological evaluations. Specifically, there was a decrease in epidermal thickness and mast cell infiltration compared to the DNCB + Vehicle group. Additionally, the topical GLZ hydrogel attenuated the AD-like phenotype by reducing oxidative stress markers. Importantly, these therapeutic effects occurred without significantly affecting blood glucose levels, highlighting the safety of the topical GLZ hydrogel. These findings demonstrate the potential of GLZ-loaded hydrogels as an effective and safe topical treatment for alleviating the symptoms of AD by targeting oxidative stress and inflammation.

High mobility group box 1 cytokine targeted topical delivery of resveratrol embedded nanoemulgel for the management of atopic dermatitis

Resveratrol is a polyphenolic compound showing anti-inflammatory activity by inhibition of high mobility group box 1 cytokine responsible for the activation of nuclear factor-κB pathway in atopic dermatitis. To evaluate the efficacy of resveratrol through topical route we have developed resveratrol-loaded nanoemulgel for the effective management of atopic dermatitis in mice model. The resveratrol-loaded nanoemulsion (0.5%, 0.75% and 1% w/w) was optimized by spontaneous nano-emulsification. The optimized resveratrol-loaded nanoemulsions showed average globule size in the 180-230 nm range and found to be monodispersed. The resveratrol nanoemulgel was prepared with a SEPINEO™ P 600 gel base and propylene glycol. Ex vivo permeation and retention study resulted in significantly higher skin retention of resveratrol from resveratrol-loaded nanoemulgel than free resveratrol-loaded gel. Preclinical efficacy of resveratrol nanoemulgel displayed promising therapeutic outcomes where, western blotting of skin tissues disclosed a significant reduction in the relative expression of high mobility group box 1, the receptor for advanced glycation end products, toll-like receptor-4 and phosphorylated nuclear factor-κB. Further, real-time polymerase chain reaction also disclosed a significant reduction in pro-inflammatory cytokines such as thymic stromal lymphopoietin, interleukin-4, interleukin-13, interleukin-31, tumor necrosis factor-α and interleukin-6. The histopathological examination of skin sections showed improvement in the skin condition. Collectively, the findings from our study showcased the significant improvement in the atopic dermatitis skin condition in mice model after topical application of resveratrol loaded nanoemulgel.

3-Bromo-4,5-dihydroxybenzaldehyde Attenuates Allergic Contact Dermatitis by Generating CD4+Foxp3+ T cells

BACKGROUND/AIM

Regulatory T cells (Tregs) play a crucial role in inflammatory responses by regulating the activity of various immune cells. M2 macrophages induced by IL-10 and TGF-β exhibit anti-inflammatory functions and induce Treg differentiation. Although the beneficial effects of 3-bromo-4,5-dihydroxybenzaldehyde (BDB) on various diseases have been widely reported, the mechanisms, through which it alleviates allergic contact dermatitis (ACD) via Tregs and macrophages, are not well understood. Therefore, this study aimed to explore whether BDB suppresses ACD and induces Treg generation.

MATERIALS AND METHODS

Mice were sensitized with 1% dinitrochlorobenzene (DNCB), followed by the application of 0.3% DNCB to their ears every 3 days for 31 days. BDB (100 mg/kg) was administered orally once daily throughout the 31 days. Cytokine and transcription factor expression were analyzed via real-time PCR and western blotting, while CD4+Foxp3+ T cell differentiation and T cell proliferation were evaluated using flow cytometry.

RESULTS

BDB exhibited therapeutic efficacy in mice with ACD. In this study, the administration of BDB promoted the upregulation of transforming growth factor beta (TGF-β)-dependent CD4+Foxp3+ T cells. BDB elicited T cell hypo-responsiveness and suppressed the expression of cytokines related to the Th1, Th2, and Th17 cell subsets. BDB-M2 macrophages directly mediated the differentiation of CD4+Foxp3+ T cells from CD4+ T cells and concurrently suppressed the proliferation of CD4+ T cells.

CONCLUSION

BDB augments M2 macrophage function and induction of Tregs confers effective protection against ACD in mice. Consequently, BDB may represent a promising therapeutic approach for the treatment of inflammatory skin diseases.

Aspergillus oryzae Fermented Plumula Nelumbinis Against Atopic Dermatitis Through AKT/mTOR and Jun Pathways

Background/Objectives: Atopic dermatitis (AD) is a chronic inflammatory skin disorder that has attracted global attention, and alkaloids from Plumula Nelumbinis have been shown to have anti-inflammatory activity. Fermentation has been used for the structural modification of natural compounds to improve bioavailability and activity, but the AD therapeutic efficacy and mechanism of the fermented Plumula Nelumbinis (FPN) are still unclear. Methods: The potential targets of FPN for AD were preliminarily screened using network pharmacology, and then PCR and WB were used to prove the therapeutic effect of FPN in AD. Results: Network pharmacology indicated that mTOR and Jun were key targets for AD. The experiments in vitro showed that FPN could effectively block AKT/mTOR and AKT/Jun-mediated inflammatory signaling pathways. Moreover, FPN can also alleviate SDS-induced inflammation in zebrafish. It is also found that the anti-inflammatory activity of Plumula Nelumbinis was enhanced by Aspergillus oryzae fermentation, and the oil phase of the fermentation product showed better activity, which may be due to microbial fermentation changing the structure of the original alkaloids. Conclusions: This study elucidated the potential mechanisms of alkaloids derived from fermented Plumula Nelumbinis against AD; it may also provide a scientific basis for the development of new drugs for AD.

Regulatory effects of Ishige okamurae extract and Diphlorethohydroxycarmalol on skin barrier function

Ethnopharmacological relevance

The pharmacological potential of marine organisms remains largely unexplored. Ishige Okamurae, commonly known as Pae, is extensively distributed over Asia. Its antioxidant, antibacterial, antiobesity, and anti-inflammatory properties are also being investigated.

Aim of the study

In most cases of atopic dermatitis, the stratum corneum, the outermost layer of the epidermis, is damaged, causing symptoms such as dryness and hyperproliferation of the epidermis. In particular, the disruption of cell junctions leads to damage of the skin barrier, exacerbating the disease and becoming a target for therapeutic development. Our study aims to investigate of Ishige okamurae extract (IOE) and a major compound derived from it, called Diphlorethohydroxycarmalol (DPHC), can help strengthen the skin barrier in animals with atopic dermatitis induced by 2,4-dinitrochlorobenzene (DNCB).

Materials and methods

In keratinocyte cell lines, HaCaT cells, the cytotoxicity of IOE and DPHC was assessed by MTT analysis. The gene expression of skin barrier factors and tight junctions were determined by real-time PCR in tumor necrosis factor-α/interferon-γ-stimulated HaCaT cells. In addition, JAK/STAT signaling pathway was performed to evaluating the mechanism of drugs by Western blot. Next, we studied the effects of IOE and DPHC on the skin of animals with DNCB-induced atopic dermatitis. We measured the expression of genes related of the skin barrier and tight junctions in their ear tissue.

Results

As a result, IOE and DPHC confirmed that the expression of skin barrier proteins (thymic stromal lymphopoietin, filaggrin, loricrin, and involucrin) was improved in the DNCB-induced atopic dermatitis model and HaCaT cells. In addition, the expression of tight junction-related proteins (claudin, occludin, and tight junction protein-1) were improved.

Conclusion

IOE and DPHC ameliorated the atopic dermatitis lesions through alleviating the pro-inflammatory responses and tight junction protein destruction. Our results suggest that IOE and DPHC could be promising candidates for enhancing skin barrier function.

The antioxidant barrier, oxidative/nitrosative stress, and protein glycation in allergy: from basic research to clinical practice

Recent studies indicate that oxidative/nitrosative stress is involved in the pathogenesis of asthma, allergic rhinitis, atopic dermatitis, and urticaria. The article aimed to review the latest literature on disruptions in redox homeostasis and protein glycation in allergy patients. It has been shown that enzymatic and non-enzymatic antioxidant systems are impaired in allergic conditions, which increases cell susceptibility to oxidative damage. Reactive oxygen/nitrogen species exacerbate the severity of asthma symptoms by activating inflammatory mediators that cause airway smooth muscle contraction, promote mucus hypersecretion, increase the permeability of lung capillaries, and damage cell membranes. Redox biomarkers could have considerable diagnostic potential in allergy patients. There is no compelling evidence to indicate that antioxidants reduce allergy symptoms' severity or slow disease progression.

Atopic dermatitis treatment: A comprehensive review of conventional and novel bioengineered approaches

Atopic dermatitis (AD) remains a challenging condition, with conventional treatments often leading to adverse effects and limited efficacy. This review explores the diverse landscape of AD treatments, encompassing conventional methods, novel topical and systemic therapies, and emerging bioengineered strategies. While conventional drug administration often requires high dosages or frequent administration, leading to adverse effects, targeted biologics have shown promise. Phototherapy and wet wrap therapy, while helpful, have limitations. Given these factors, the need for modern and effective therapeutic strategies for AD is pressing. Complementary or alternative therapies have garnered significant attention in recent years as a compelling treatment for AD. Among these, functionalized biomaterials and textiles with physicochemical, nanotechnology-based characteristics, or bioengineered features are some of the most common typical adjuvant therapies. The multifunctional-engineered biomaterials, as a new generation of biomedical materials, and stem cells, seem to hold tremendous promise for the treatment of dermatological diseases like AD. Biomaterials have seen great success, especially in various medical fields, due to their unique and adaptable characteristics. These materials, including collagen, PCL, and PLGA, offer unique advantages, such as biocompatibility, biodegradability, controlled drug release, and enhanced drug retention.

Sphingosylphosphorylcholine Promotes Th9 Cell Differentiation Through Regulation of Smad3, STAT5, and β-Catenin Pathways

Sphingosylphosphorylcholine (SPC) is one of sphingomyelin-derived sphingolipids. SPC levels are increased in ascitic fluids of ovarian cancer patients and stratum corneum of atopic dermatitis (AD) patients. SPC has antitumor activity against several cancer cells by reducing proliferation and migration and increasing apoptosis in vitro. SPC can also cause scratching, potentially exacerbating symptoms of AD. However, the role of SPC in modulating immune responses, particularly in the differentiation of Th9 cells, which carry the most powerful antitumor activity among CD4+ T cells, has yet to be investigated. In this study, we found that SPC is another inducer of Th9 cell differentiation by replicating TGF-β. SPC upregulated Smad3, STAT5, and β-catenin signaling pathways. Increased Smad3 and STAT5 signaling pathways by SPC promoted the differentiation of Th9 cells and increased β-catenin signaling pathway resulted in a less-exhausted, memory-like phenotype of Th9 cells. Increased Smad3, STAT5 and β-catenin signaling pathways by SPC were mediated by increased mitochondrial ROS. These results suggest that SPC is an important endogenous inducer of Th9 cell differentiation and may be one of the targets for treating Th9-related diseases, and that enhancing Th9 differentiation by SPC may be helpful in adoptive T cell therapy for cancer treatment.

Biologics and oral systemic treatment preferences in patients and physicians for moderate-to-severe atopic dermatitis: a discrete choice experiment in the United Kingdom and Germany

Background: As the available treatments for moderate-to-severe atopic dermatitis (AD) expand, understanding patient and physician preferences becomes crucial for informed decision-making.

Objective: To quantify patient and physician preferences for biologics and oral systemic AD treatment attributes.

Materials and methods: We conducted a cross-sectional, online discrete choice experiment (DCE) involving 306 AD patients and 206 physicians throughout the United Kingdom and Germany. Qualitative interviews identified the key attributes for inclusion in the DCE. Each choice task comprised two hypothetical patient profiles. Data were analyzed using a random-parameters logit model.

Results: Results indicated a significant emphasis on efficacy, with reducing sleep disturbance and itch ranking first and second among patients, and the reverse for physicians. Time to itch relief was the third most important efficacy attribute for both groups, but relatively more important for patients than for physicians. For both groups, the risk of eye problems was the most important safety concern of those included. Mode of administration was not of great importance compared to efficacy and safety attributes.

Conclusions: Our findings suggest patients prioritize sleep disturbance, an attribute not captured in prior preference studies in AD, time to itch relief and itch. These findings emphasize the importance of addressing sleep-related issues, whilst also targeting fast itch control, to enhance patients' well-being.

In utero exposure to per - and polyfluoroalkyl substances (PFAS) associates with altered human infant T helper cell development

Background

Environmental exposures to chemical toxicants during gestation and infancy can dysregulate multiple developmental processes, causing lifelong effects. There is compelling evidence of PFAS-associated immunotoxicity in adults and children. However, the effect of developmental PFAS exposure on infant T-cell immunity is unreported, and, if present, could be implicated in immune-related health outcomes.

Objectives

We seek to model longitudinal changes in CD4+ T-cell subpopulations from birth through 12 months and their association with in-utero PFAS exposure and postnatal CD4+ T-cell frequencies and functions.

Methods

Maternal-infant dyads were recruited as part of the UPSIDE-ECHO cohort during the first trimester between 2015 and 2019 in Rochester, New York; dyads were followed through the infant's first birthday. Maternal PFAS concentrations (PFOS, PFOA, PFNA, and PFHXS) were quantified in serum during the second trimester using high-performance liquid chromatography and tandem mass spectrometry. Infant lymphocyte frequencies were assessed at birth, 6- and 12-months using mass cytometry and high-dimensional clustering methods. Linear mixed-effects models were employed to analyze the relationship between maternal PFAS concentrations and CD4+ T-cell subpopulations (n=200). All models included a PFAS and age interaction and were adjusted for parity, infant sex, and pre-pregnancy body mass index.

Results

In-utero PFAS exposure correlated with multiple CD4+ T-cell subpopulations in infants. The greatest effect sizes were seen in T-follicular helper (Tfh) and T-helper 2 (Th2) cells at 12 months. A log 2 -unit increase in PFOS was associated with lower Tfh [0.17% (95%CI: -0.30, -0.40)] and greater Th2 [0.27% (95%CI: 0.18, 0.35)] cell percentages at 12 months. Similar trends were observed for PFOA, PFNA, and PFHXS.

Discussion

Maternal PFAS exposures correlate with cell-specific changes in the infant T-cell compartment, including key CD4+ T-cell subpopulations that play central roles in coordinating well-regulated, protective immunity. Future studies into the role of PFAS-associated T-cell distribution and risk of adverse immune-related health outcomes in children are warranted.

Resolution of Chronic Inflammation, Restoration of Epigenetic Disturbances and Correction of Dysbiosis as an Adjunctive Approach to the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease with multifactorial and unclear pathogenesis. Its development is characterized by two key elements: epigenetic dysregulation of molecular pathways involved in AD pathogenesis and disrupted skin and gut microbiota (dysbiosis) that jointly trigger and maintain chronic inflammation, a core AD characteristic. Current data suggest that failed inflammation resolution is the main pathogenic mechanism underlying AD development. Inflammation resolution is provided by specialized pro-resolving mediators (SPMs) derived from dietary polyunsaturated fatty acids acting through cognate receptors. SPM levels are reduced in AD patients. Administration of SPMs or their stable, small-molecule mimetics and receptor agonists, as well as supplementation with probiotics/prebiotics, demonstrate beneficial effects in AD animal models. Epidrugs, compounds capable of restoring disrupted epigenetic mechanisms associated with the disease, improve impaired skin barrier function in AD models. Based on these findings, we propose a novel, multilevel AD treatment strategy aimed at resolving chronic inflammation by application of SPM mimetics and receptor agonists, probiotics/prebiotics, and epi-drugs. This approach can be used in conjunction with current AD therapy, resulting in AD alleviation.

Anti-Inflammatory Effect of Ethanol Extract from Hibiscus cannabinus L. Flower in Diesel Particulate Matter-Stimulated HaCaT Cells

BACKGROUND/OBJECTIVES

Diesel Particulate Matter (DPM) is a very small particulate matter originating from cities, factories, and the use of fossil fuels in diesel vehicles. When DPM permeates the skin, it causes inflammation, leading to severe atopic dermatitis. Hibiscus cannabinus L. (Kenaf) seeds and leaves possess various beneficial properties, including anti-coagulation, antioxidant, and anti-inflammation effects. In this study, we investigated the anti-inflammatory effects of an ethanol extract of Hibiscus cannabinus L. flower (HCFE) in HaCaT cells stimulated with 100 μg/mL of DPM.

METHODS

The anthocyanin content of HCFE was analyzed, and its antioxidant capacity was investigated using the DPPH assay. After inducing inflammation with 100 ug/mL of DPM, the cytotoxicity of HCFE 25, 50, and 100 ug/mL was measured, and the inhibitory effect of HCFE on inflammatory mediators was evaluated.

RESULTS

Anthocyanin and myricetin-3-O-glucoside were present in HCFE and showed high antioxidant capacity. In addition, HCFE decreased the mRNA expression of inflammatory cytokines and chemokines such as IL-1β, IL-4, IL-6, IL-8, IL-13, and MCP-1, and significantly reduced the gene expression of CXCL10, CCL5, CCL17, and CCL22, which are known to increase in atopic dermatitis lesions. Furthermore, HCFE reduced intracellular reactive oxygen species (ROS) production, and down-regulated the activation of NF-κB, MAPKs. Inhibition of the NLRP-3 inflammasome was observed in DPM-stimulated HaCaT cells. In addition, the restoration of filaggrin and involucrin, skin barrier proteins destroyed by DPM exposure, was confirmed.

CONCLUSIONS

These data suggest that HCFE could be used to prevent and improve skin inflammation and atopic dermatitis through the regulation of inflammatory mediators and the inhibition of skin water loss.

Emerging Biologic Therapies for the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a prevalent inflammatory skin disease having a significant impact on patients' quality of life. Conventional treatments, including topical therapies and systemic immunosuppressants, often have limited efficacy and long-term safety concerns. Emerging biologic therapies target specific immune pathways implicated in AD pathogenesis, offering new therapeutic options in a disease known for its complex immune pathomechanisms. This review focuses on novel biologics under investigation, particularly those targeting specific immune pathways such as interleukin-4 (IL-4), IL-13, IL-22, IL-31, thymic stromal lymphopoietin (TSLP), and OX40-OX40L axis. Interleukin-4 and IL-13 inhibitors aim to reduce Th2-driven inflammation, while IL-22 inhibitors focus on restoring skin barrier function. Interleukin-31 inhibitors help alleviate pruritus, a major symptom in AD. OX40-OX40L pathway inhibitors can selectively suppress the activity of pathogenic T cells, without inducing significant immunosuppression. Bispecific antibodies targeting both IL-4 and IL-31 pathways are emerging as potential dual-action treatment for AD. Thymic stromal lymphopoietin inhibitors offer a novel strategy to control inflammation. While many of these therapies offer promising safety and efficacy profiles, long-term studies and real-world data are essential to confirm their lasting impact. This review highlights the potential of these emerging systemic therapies to continue transforming AD management and improve patient outcomes.

Long-term efficacy and safety of dupilumab for moderate-to-severe atopic dermatitis: a prospective real-world cohort study in China

Backgrounds

Dupilumab has demonstrated remarkable efficacy and safety in clinical trials for moderate-to-severe atopic dermatitis (AD). However, long-term real-world evidence, especially in the Chinese population, remains limited.

Objective

To investigate the long-term efficacy and safety of dupilumab for moderate-to-severe AD in a real-world clinical setting in China and analyze factors that may influence its long-term treatment outcomes.

Methods

This prospective, observational real-world study included moderate-to-severe AD patients from the AD cohort of the dermatology department of Chongqing Hospital of Traditional Chinese Medicine who received dupilumab treatment for≥52 weeks. Efficacy and adverse events were assessed at baseline, weeks 4, 16, 24, and 52. Multivariate logistic regression analysis was used to identify predictive factors for achieving EASI 50 and EASI 75 at week 52.

Results

A total of 124 patients were included. At week 52, EASI, SCORAD, IGA, NRS, and DLQI scores were significantly improved compared to baseline. The proportions of patients achieving EASI-50/75 were 50.81%/29.84%, 72.58%/42.74%, 75%/53.23%, and 67.74%/41.94% at weeks 4, 16, 24 and 52, respectively. Female sex, absence of atopic comorbidities, higher baseline EASI, and medication compliance were positive predictive factors for 52-week EASI-50/75. Eosinophil elevation predicted lower EASI-50 attainment. Nineteen adverse events occurred during the 52-week period (incidence rate: 14.52%), mostly mild and manageable.

Conclusions

Dupilumab demonstrated significant efficacy and a low incidence of adverse events over 52 weeks in Chinese patients with moderate-to-severe AD, making it an effective and safe long-term treatment option. Predictive factors were identified to guide treatment optimization.

Deciphering the Etiologies of Adult Erythroderma: An Updated Guide to Presentations, Diagnostic Tools, Pathophysiologies, and Treatments

Erythroderma, an inflammatory skin condition characterized by widespread erythema with variable degrees of exfoliation, pustulation, or vesiculobullous formation, is associated with high morbidity and mortality. Determining the underlying cause of erythroderma frequently presents a diagnostic challenge, which may contribute to the condition's relatively poor prognosis. This review covers the clinical presentation, pathophysiology, diagnosis, and treatment of erythroderma. It discusses similarities and differences among the many underlying etiologies of the condition and differences between erythrodermic and non-erythrodermic presentations of the same dermatosis. Finally, this article explores current research that may provide future tools in the diagnosis and management of erythroderma.

Anti-chitinase-3-like 1 antibody attenuated atopic dermatitis-like skin inflammation through inhibition of STAT3-dependent CXCL8 expression

BACKGROUND AND PURPOSE

Chitinase-3-like 1 (CHI3L1) causes skin inflammation in the progression of atopic dermatitis. We investigated if anti-CHI3L1 antibody could prevent the development of atopic dermatitis and its mechanisms of action.

EXPERIMENTAL APPROACH

The effect of CHI3L1 antibody on phthalic anhydride-induced atopic dermatitis animal model and in vitro reconstructed human skin (RHS) model were investigated. Expression and release of atopic dermatitis-related cytokines were determined using an enzyme-linked immunosorbent assay, and RT-qPCR, STAT3 and CXCL8 signalling were measured by western blotting.

KEY RESULTS

Anti-CHI3L1 antibody suppressed phthalic anhydride-induced epidermal thickening, clinical score, IgE level and infiltration of inflammatory cells, and reduced phthalic anhydride-induced inflammatory cytokines concentration. In addition, CHI3L1 antibody treatment inhibited the expression of STAT3 activity in phthalic anhydride-treated skin. It was also confirmed that CHI3L1 antibody treatment alleviated atopic dermatitis-related inflammation in the RHS model. The inhibitory effects of CHI3L1 antibody was similar or more effective compared with that of the IL-4 antibody. We further found that CHI3L1 is associated with CXCL8 by protein-association network analysis. siRNA of CHI3L1 blocked the mRNA levels of CHI3L1, IL-1β, IL-4, CXCL8, TSLP, and the expression of CHI3L1 and p-STAT, and the level of CXCL8, whereas recombinant level of CXCL8 was elevated. Moreover, siRNA of STAT3 reduced the mRNA level of these cytokines. CHI3L1 and p-STAT3 expression correlated with the reduced CXCL8 level in the RHS in vitro model.

CONCLUSION AND IMPLICATIONS

Our data demonstrated that CHI3L1 antibody could be a promising effective therapeutic drug for atopic dermatitis.

The skin microbiome stratifies patients with cutaneous T cell lymphoma and determines event-free survival

Mycosis fungoides (MF) is the most common entity of Cutaneous T cell lymphomas (CTCL) and is characterized by the presence of clonal malignant T cells in the skin. The role of the skin microbiome for MF development and progression are currently poorly understood. Using shotgun metagenomic profiling, real-time qPCR, and T cell receptor sequencing, we compared lesional and nonlesional skin of 20 MF patients with early and advanced MF. Additionally, we isolated Staphylococcus aureus and other bacteria from MF skin for functional profiling and to study the S. aureus virulence factor spa. We identified a subgroup of MF patients with substantial dysbiosis on MF lesions and concomitant outgrowth of S. aureus on plaque-staged lesions, while the other MF patients had a balanced microbiome on lesional skin. Dysbiosis and S. aureus outgrowth were accompanied by ectopic levels of cutaneous antimicrobial peptides (AMPs), including adaptation of the plaque-derived S. aureus strain. Furthermore, the plaque-derived S. aureus strain showed a reduced susceptibility towards antibiotics and an upregulation of the virulence factor spa, which may activate the NF-κB pathway. Remarkably, patients with dysbiosis on MF lesions had a restricted T cell receptor repertoire and significantly lower event-free survival. Our study highlights the potential for microbiome-modulating treatments targeting S. aureus to prevent MF progression.

Hydrogels: a promising therapeutic platform for inflammatory skin diseases treatment

Inflammatory skin diseases, such as psoriasis and atopic dermatitis, pose significant health challenges due to their long-lasting nature, potential for serious complications, and significant health risks, which requires treatments that are both effective and exhibit minimal side effects. Hydrogels offer an innovative solution due to their biocompatibility, tunability, controlled drug delivery capabilities, enhanced treatment adherence and minimized side effects risk. This review explores the mechanisms that guide the design of hydrogel therapeutic platforms from multiple perspectives, focusing on the components of hydrogels, their adjustable physical and chemical properties, and their interactions with cells and drugs to underscore their clinical potential. We also examine various therapeutic agents for psoriasis and atopic dermatitis that can be integrated into hydrogels, including traditional drugs, novel compounds targeting oxidative stress, small molecule drugs, biologics, and emerging therapies, offering insights into their mechanisms and advantages. Additionally, we review clinical trial data to evaluate the effectiveness and safety of hydrogel-based treatments in managing psoriasis and atopic dermatitis under complex disease conditions. Lastly, we discuss the current challenges and future opportunities for hydrogel therapeutics in treating psoriasis and atopic dermatitis, such as improving skin barrier penetration and developing multifunctional hydrogels, and highlight emerging opportunities to enhance long-term safety and stability.

Type 2 Innate Lymphoid Cells and Skin Fibrosis in a Murine Model of Atopic Dermatitis-Like Skin Inflammation

BACKGROUND

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease. Although murine studies have demonstrated that type 2 innate lymphoid cells (ILCs) mediate type 2 skin inflammation, their role in skin fibrosis in AD remains unclear. This study investigated whether type 2 ILCs are involved in skin fibrosis using an AD-like murine model.

METHODS

C57BL/6 mice were treated epicutaneously with Aspergillus fumigatus (Af) for 5 consecutive days per week for 5 weeks to induce skin fibrosis. Mature lymphocyte deficient Rag1-/- mice were also used to investigate the role of type 2 ILCs in skin fibrosis.

RESULTS

The clinical score and transepidermal water loss (TEWL) were significantly higher in the AD group than in the control group. The AD group also showed significantly increased epidermal and dermal thicknesses and significantly higher numbers of eosinophils, neutrophils, mast cells, and lymphocytes in the lesional skin than the control group. The lesional skin of the AD group showed increased stain of collagen and significantly higher levels of collagen than the control group (10.4 ± 2.2 µg/mg vs. 1.6 ± 0.1 µg/mg, P < 0.05). The AD group showed significantly higher populations of type 2 ILCs in the lesional skin compared to the control group (0.08 ± 0.01% vs. 0.03 ± 0.01%, P < 0.05). These findings were also similar with the AD group of Rag1-/- mice compared to their control group. Depletion of type 2 ILCs with anti-CD90.2 monoclonal antibodies significantly improved clinical symptom score, TEWL, and infiltration of inflammatory cells, and significantly decreased levels of collagen were observed in the AD group of Rag1-/- mice (1.6 ± 0.0 μg/mg vs. 4.5 ± 0.3 μg/mg, P < 0.001).

CONCLUSION

In the Af-induced AD-like murine model, type 2 ILCs were elevated, with increased levels of collagen. Additionally, removal of type 2 ILCs resulted in decreased collagen levels and improved AD-like pathological findings. These findings suggest that type 2 ILCs play a role in the mechanism of skin fibrosis in AD.

Interleukin Profiling in Atopic Dermatitis and Chronic Nodular Prurigo

The clinical manifestations of atopic dermatitis (AD) and chronic nodular prurigo (CNPG) include pruritus and eczema/lesions, posing significant challenges for patients. Th2 cells and ILC2, marked by cytokine production-particularly IL-4/13-are crucial therapeutic targets. Despite displaying a dose-dependent lack of pruritus induction post-injection, IL-13 acts through the IL-13Rα1 and IL-13Rα2 receptor system. Our study focused on investigating ex vivo skin biopsies in AD (n = 17), CNPG (n = 14) and healthy controls (HC; n = 10), examining the gene expression landscape of interleukins linked with pruritus (IL-13, IL-4, IL-31) and their corresponding receptors. Compared to HC, results revealed a significant upregulation of IL-4, IL-13, and IL-13RA1 in AD, whereas CNPG did not show increased IL13 expression. Notably, the decoy receptor IL-13RA2 displayed intriguing patterns, with AD showing a marked increase compared to both HC and CNPG. Positive correlations between receptor expression and itch intensity and hyperkinesis sensation underscore clinical relevance, potentially serving as biomarkers. The findings suggest a pivotal role of IL-4 and IL-13, along with IL-13RA1, in pruritus pathogenesis in both entities, while IL-13 upregulation in AD is countered by IL-13RA2. The comparable expression of IL-13RA2 to HC in CNPG suggests the absence of this regulatory mechanism, potentially worsening the disease and leading to prolonged scratching behavior. These insights illuminate the intricate interplay of interleukins and receptors in different pruritus phenotypes, laying the groundwork for understanding underlying mechanisms and offering avenues for therapeutic intervention.

The EGR1-Artemin Axis in Keratinocytes Enhances the Innervation of Epidermal Sensory Neurons during Skin Inflammation Induced by House Dust Mite Extract from Dermatophagoidesfarinae

Epidermal hyperinnervation is a critical feature of pruritus during skin inflammation. However, the mechanisms underlying epidermal hyperinnervation are unclear. This study investigates the role of the transcription factor EGR1 in epidermal innervation by utilizing wild-type (Egr1+/+) and Egr1-null (Egr1‒/‒) mice topically applied Dermatophagoides farinae extract from dust mite. Our findings revealed that Egr1‒/‒ mice exhibited reduced scratching behaviors and decreased density of epidermal innervation compared with Egr1+/+ mice. Furthermore, we identified artemin, a neurotrophic factor, as an EGR1 target responsible for Dermatophagoides farinae extract-induced hyperinnervation. It has been demonstrated that Dermatophagoides farinae extract stimulates toll-like receptors in keratinocytes. To elucidate the cellular mechanism, we stimulated keratinocytes with Pam3CSK4, a toll-like receptor 1/2 ligand. Pam3CSK4 triggered a toll-like receptor 1/2-mediated signaling cascade involving IRAK4, IκB kinase, MAPKs, ELK1, EGR1, and artemin, leading to increased neurite outgrowth and neuronal migration. In addition, increased expression of EGR1 and artemin was observed in the skin tissues of patients with atopic dermatitis. These findings highlight the significance of the EGR1-artemin axis in keratinocytes, promoting the process of epidermal innervation and suggesting it as a potential therapeutic target for alleviating itch and pain associated with house dust mite-induced skin inflammation.

Pharmacokinetics and pharmacodynamics of itepekimab in adults with moderate-to-severe atopic dermatitis: Results from two terminated phase II trials

Interleukin-33 (IL-33) is a proinflammatory alarmin cytokine released by damaged epithelial tissue cells that initiates and amplifies both type 1 and type 2 inflammatory cascades. A role for IL-33 in atopic dermatitis (AD; a chronic, relapsing type 2 inflammatory disease of the skin) has been proposed. Itepekimab is a novel human IgG4P monoclonal antibody against IL-33, currently in clinical development for chronic obstructive pulmonary disease (COPD). Two global phase II studies-a dose-ranging itepekimab monotherapy study (NCT03738423) and a proof-of-concept study of itepekimab alone and in combination with dupilumab (NCT03736967)-were conducted in patients with moderate-to-severe AD to assess safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy; both studies were terminated following an interim analysis of the proof-of-concept study, which failed to demonstrate the efficacy of itepekimab. In these two studies, itepekimab exhibited linear and dose-proportional pharmacokinetics. Pharmacodynamics of total IL-33 indicated that itepekimab saturated binding to the target in serum at 300 mg q2w and q4w doses, and decreased blood eosinophil counts. Concentration-time profiles of itepekimab and total IL-33 were similar for itepekimab with or without dupilumab, and between East Asian and non-East Asian subgroups. Itepekimab was generally well tolerated, both alone and in combination with dupilumab. The lack of clinical efficacy for itepekimab observed in these studies suggests that IL-33 may not be a key pathogenic driver in moderate-to-severe AD.

Oral and topical administration of a geranyl acetophenone attenuates DNCB-induced atopic dermatitis-like skin lesions in BALB/c mice

Atopic dermatitis (AD) is a chronic, allergic inflammatory skin disorder that lacks a definite cure. Using a mouse DNCB-induced AD-like skin lesions model, this study evaluated the potential therapeutic utility of tHGA as an oral and topical treatment for AD. Male BALB/c mice were sensitised and challenged with 1% and 0.5% DNCB on their shaved dorsal skin. Mice in the treatment group were administered tHGA (20, 40, and 80 mg/kg) orally three times per week for 2 weeks, or tHGA (0.2%, 1%, and 5%) topically once daily for 12 days. On day 34, the mice were euthanized, and blood and dorsal skin samples were obtained for analysis. All doses of orally and topically administered tHGA significantly improved scratching, epidermal thickness, blood eosinophilia and mast cell infiltration. There was a minor discrepancy between the two routes of administration, with orally treated tHGA showing significant reductions in Scoring of Atopic Dermatitis (SCORAD), tissue eosinophil infiltration, serum IgE and skin IL-4 levels with treatment of 40 and 80 mg/kg tHGA, whereas topically applied tHGA showed significant reductions in all dosages. These findings suggest that tHGA exhibited therapeutic potential for AD as both oral and topical treatment ameliorates AD-like symptoms in the murine model.

Association of maternal constipation and risk of atopic dermatitis in offspring

Objectives: Atopic dermatitis (AD) is a chronic and relapsing dermatologic disease that can affect individuals of all ages, including children and adults. The prevalence of AD has increased dramatically over the past few decades. AD may affect children's daily activities, increase their parents' stress, and increase health expenditure. Constipation is a worldwide issue and may affect the gut microbiome. Some research has indicated that constipation might be associated with risk of atopic disease. The primary objective of this retrospective cohort study was to extend and to explore the link between maternal constipation and risk of atopic dermatitis in offspring. Methods: Using the Longitudinal Health Insurance Database, a subset of Taiwan's National Health Insurance Research Database, we identified 138,553 mothers with constipation and 138,553 matched controls between 2005 and 2016. Propensity score analysis was used matching birth year, child's sex, birth weight, gestational weeks, mode of delivery, maternal comorbidities, and antibiotics usage, with a ratio of 1:1. Multiple Cox regression and subgroup analyses were used to estimate the adjusted hazard ratio of child AD. Results: The incidence of childhood AD was 66.17 per 1,000 person-years in constipated mothers. By adjusting child's sex, birth weight, gestational weeks, mode of delivery, maternal comorbidities, and received antibiotics, it was found that in children whose mother had constipation, there was a 1.26-fold risk of AD compared to the children of mothers without constipation (adjusted hazard ratio [aHR]: 1.26; 95% CI, 1.25-1.28). According to subgroup analyses, children in the maternal constipation group had a higher likelihood of AD irrespective of child's sex, birth weight, gestational weeks, mode of delivery, and with or without comorbidities, as well as usage of antibiotics during pregnancy. Compared to the non-constipated mothers, the aHR for the constipated mothers with laxative prescriptions <12 and ≥12 times within one year before the index date were 1.26; 95% CI, 1.24 -1.28 and 1.40; 95% CI, 1.29-1.52, respectively. Conclusion: Maternal constipation was associated with an elevated risk of AD in offspring. Clinicians should be aware of the potential link to atopic dermatitis in the children of constipation in pregnant women and should treat gut patency issues during pregnancy. More study is needed to investigate the mechanisms of maternal constipation and atopic diseases in offspring.

Pyroptosis and its role in autoimmune skin disease

Autoimmune skin disease is a kind of heterogeneous disease with complicated pathogenesis. Many factors such as genetic, infectious, environmental and even psychological factors may interact together to trigger a synergistic effect for the development of abnormal innate and adaptive immune responses. Although the exact mechanisms remain unclear, recent evidence suggests that pyroptosis plays a pivotal role in the development of autoimmune skin disease. The feature of pyroptosis is the first formation of pores in cellular membranes, then cell rupture and the release of intracellular substances and pro-inflammatory cytokines, such as interleukin-1 beta (IL-1β) and IL-18. This hyperactive inflammatory programmed cell death damages the homeostasis of the immune system and advances autoimmunity. This review briefly summarises the molecular regulatory mechanisms of pyrin domain-containing protein 3 (NLRP3) inflammasome and gasdermin family, as well as the molecular mechanisms of pyroptosis, highlights the latest progress of pyroptosis in autoimmune skin disease, including systemic lupus erythematosus, psoriasis, atopic dermatitis and systemic scleroderma and attempts to identify its potential advantages as a therapeutic target or prognostic biomarker for these diseases.

Pediococcus pentosaceus KF159 alleviates house dust mite-induced atopic dermatitis by promoting IL10 production and regulatory T cell induction

Atopic dermatitis (AD) is a chronic immune disease that requires long-term management owing to its relative ease of recurrence. However, steroid treatment is limited owing to the side effects. Therefore, research on therapeutics with proven safety is required. Here, we evaluated the anti-allergic activity of the probiotic strain Pediococcus pentosaceus KF159 (PPKF159) with an ex vivo mouse model sensitized with ovalbumin (OVA) and a mouse model of AD induced by house dust mites. Changes in pathological symptoms were confirmed based on the clinical status of the AD-induced lesion site and the levels of T helper type 2 (Th2)-derived cytokines and immunoglobulin E (IgE). In addition, cell-mediated responses and related mechanisms were elucidated using various kinds of primary cells including splenocytes, mesenteric lymph nodes, Peyer's patch, and bone marrow-derived dendritic cells (BMDCs) in vitro and ex vivo. Oral administration of PPKF159 alleviated AD-like clinical symptoms such as erythema, edema, hemorrhage, and increased tissue thickness, and suppressed the production of Th2-associated cytokines and serum IgE while increasing T helper type 1 (Th1)-mediated cytokine production. PPKF159 induced tolerogenic dendritic cells (tol-DCs) by increasing the expression of ICOS-L, PD-L1, and IDO which were closely related to Treg induction in PPKF159-treated BMDCs. In addition, BMDCs and naive T cells co-cultured in the presence of PPKF159 had elevated IL10 production and increased proportions of CD4+CD25+Foxp3+ Tregs compared to the absence of PPKF159. This study showed that PPKF159 relieved AD-like clinical symptoms, modulated the Th1/Th2 immune balance, and inhibited IgE production in a mouse AD model. PPKF159 induced the transformation of dendritic cells into tolerogenic versions. These induced tol-DCs directly enhanced the production of IL10 or improved the secretion of IL10 through the induction of CD4+CD25+Foxp3+ Treg cells, thereby improving AD. These results suggest that PPKF159 can be applied as a functional food material for the treatment and prevention of AD.

Cheungsam Seed Husk Extract Reduces Skin Inflammation through Regulation of Inflammatory Mediator in TNF-α/IFN-γ-Induced HaCaT Cells

Cannabis contains numerous natural components and has several effects such as anticancer, anti-inflammatory and antioxidant. Cheungsam is a variety of non-drug-type hemp, developed in Korea and is used for fiber (stem) and oil (seed). The efficacy of Cheungsam on skin is not yet known, and although there are previous studies on Cheungsam seed oil, there are no studies on Cheungsam seed husk. In this study, we investigated the potential of Cheungsam seed husk ethanol extract (CSSH) to alleviate skin inflammation through evaluating the gene and protein expression levels of inflammatory mediators. The results showed that CSSH reduced pro-inflammatory cytokines (IL-1β, IL-6, IL-8, MCP-1 and CXCL10) and atopic dermatitis-related cytokines (IL-4, CCL17, MDC and RANTES) in TNF-α/IFN-γ-induced HaCaT cells. Furthermore, ERK, JNK and p38 phosphorylation were decreased and p-p65, p-IκBα, NLRP3, caspase-1, p-JAK1 and p-STAT6 were suppressed after CSSH treatment. CSSH significantly increased the level of the skin barrier factors filaggrin and involucrin. These results suggest that Cheungsam seed husk ethanol extract regulates the mechanism of skin inflammation and can be used as a new treatment for skin inflammatory diseases.

Calycosin enhances Treg differentiation for alleviating skin inflammation in atopic dermatitis

ETHNOPHARMACOLOGICAL RELEVANCE

Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disorder that poses a significant global health challenge. There is a lack of safe and effective medications to treat AD. Astragalus membranaceous is a traditional Chinese medicine widely used in clinical treatment of skin diseases. Calycosin (CA), derived from the root of Astragalus membranaceous, exhibits dual attributes of anti-inflammatory and antioxidant properties, suggesting its promise for addressing cutaneous inflammation. Nonetheless, the precise mechanisms underlying CA's therapeutic actions in AD remain elusive.

AIM OF THE STUDY

This study aimed to evaluate the efficacy and safety of CA in treating AD while also delving into the mechanistic underpinnings of CA's action in AD.

MATERIALS AND METHODS

The cell viability and anti-inflammatory impacts of CA in vitro were first gauged using CCK-8 and RT-qPCR. The potential mechanisms of CA were then probed using modular pharmacology. Flow cytometry was employed to ascertain the differentiation of Treg and Th17 cells derived from naïve T cells, as well as the proportions and mean fluorescence intensity (MFI) of human iTreg cells. The expressions of IL-10 and TGF-β1 were measured and Treg suppression assay was performed. The in vivo therapeutic efficacy of topical CA application was assessed using a calcipotriol (MC903)-induced AD mouse model. The expression metrics of inflammatory cytokines, IL-17A, FOXP3, and RORγt were authenticated via immunohistochemistry, RT-qPCR, Western blot, and ELISA.

RESULTS

CA exhibited a favorable safety profile and reduced the mRNA expressions of Th2 inflammatory cytokines in HaCaT cells. Modular pharmacology analysis pinpointed Th17 differentiation as the pivotal mechanism behind CA's therapeutic effect on AD. In vitro, CA fostered the differentiation of naïve T cells into Tregs while inhibiting their differentiation into Th17 cells. Furthermore, CA augmented the proliferation of human iTregs. In vivo, CA alleviated skin manifestations and decreased the levels of inflammatory mediators (IL-4, IL-5, IL-13, TSLP, and NF-κB related cytokines) in AD-like mouse models. Simultaneously, it regulated Treg/Th17 balance through suppressing IL-17A and RORγt expressions and bolstering FOXP3 expression.

CONCLUSIONS

The study provides insights into the mechanistic pathways through which CA exerts its anti-inflammatory effects, particularly through promoting Treg cell differentiation and inhibiting Th17 cell differentiation. Furthermore, CA emerges as an alternative or adjunctive treatment strategy for managing AD.

Therapeutic potential of ginseng leaf extract in inhibiting mast cell-mediated allergic inflammation and atopic dermatitis-like skin inflammation in DNCB-treated mice

Ginseng leaves are known to contain high concentrations of bioactive compounds, such as ginsenosides, and have potential as a treatment for various conditions, including fungal infections, cancer, obesity, oxidative stress, and age-related diseases. This study assessed the impact of ginseng leaf extract (GLE) on mast cell-mediated allergic inflammation and atopic dermatitis (AD) in DNCB-treated mice. GLE reduced skin thickness and lymph node nodules and suppressed the expression and secretion of histamine and pro-inflammatory cytokines. It also significantly lowered the production of inflammatory response mediators including ROS, leukotriene C4 (LTC4), prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). GLE inhibited the phosphorylation of MAPKs (ERK, P38, JNK) and the activation of NF-κB, which are both linked to inflammatory cytokine expression. We demonstrated that GLE's inhibitory effect on mast cell-mediated allergic inflammation is due to the blockade of the NF-κB and inflammasome pathways. Our findings suggest that GLE can be an effective therapeutic agent for mast-cell mediated and allergic inflammatory conditions.

The association between expression of CD200 on B lymphocytes and the count of eosinophils and basophils in atopic dermatitis patients with and without dupilumab therapy - Pilot study

BACKGROUND

Eosinophils and basophils are implicated in allergic reactions, and the molecule CD200 on B cells may have regulatory functions. Assessing the associations between the expression of CD200 on B lymphocytes and eosinophils and basophils helps unravel the complex immune interactions in atopic dermatitis, aiding in targeted therapeutic approaches.

OBJECTIVE

The aim of our study is to evaluate the association between the count of eosinophils, basophils, CD16+ eosinophils, CD203+ basophils, the expression of activation marker CD200 on B cells and on their subsets in patients suffering from atopic dermatitis with and without dupilumab and in control group.

MATERIALS AND METHODS

Altogether we examined 75 subjects: 45 patients suffering from atopic dermatitis -32 patients without dupilumab treatment, 13 patients with dupilumab treatment and 30 subjects as a control group. Immunophenotype was examined by flow cytometry in which monoclonal antibodies with fluorescent molecules were used. For statistical analysis we used non-parametric Kruskal-Wallis one-factor analysis of variance with post-hoc by Dunn's test with Bonferroni modification and the Spearman's rank correlation coefficient with calculation of R2 (%, percent of Variation Explained).

RESULTS

In patients with dupilumab therapy we confirmed the association between absolute eosinophils and expression of molecule CD200 on total B lymphocytes (in 23.9 %), non-switched (in 27.2 %), naive (in 25 %) and memory (in 20.3 %) B lymphocytes and between relative eosinophils and expression of CD200 on total B lymphocytes (in 22.8 % %), non-switched (in 29 %), naive (in 21.3 %) and memory (in 22.3 %) B lymphocytes. This association is low in AD patients without dupilumab and even non linear in control healthy subjects.

CONCLUSION

The higher association between eosinophils and expression of CD200 molecule on memory, naive and non switched B lymphocytes in AD patients under dupilumab therapy suggests that activation of B lymphocytes is caused by IL-4, whose production involves eosinophils and the CD200 molecule on B lymphocytes.

Ursodeoxycholic acid alleviates atopic dermatitis-associated inflammatory responses in HaCaT and RBL-2H3 cells and DNCB/DFE-treated mice

AIMS

Ursodeoxycholic acid (UDCA) is a hydrophilic dihydroxy bile acid used for cholestatic liver disease and exhibits antioxidant, antitumor, and anti-inflammatory effects. However, its potential effects on atopic dermatitis (AD) have not been elucidated. This study aimed to evaluate the efficacy of UDCA in inhibiting the inflammatory response and alleviating lesions in AD-like mice.

MAIN METHODS

To investigate the efficacy of UDCA in AD-like inflammatory responses, tumor necrosis factor-alpha (TNF-α)- and interferon-gamma (IFN-γ)-stimulated HaCaT cells and anti-dinitrophenyl immunoglobulin E (DNP-IgE)- and human serum albumin (HSA)-stimulated RBL-2H3 cells were used to investigate the levels of inflammatory factors and their mechanisms. AD-like lesions were induced by applying DNCB/DFE to mice. The effect of UDCA administration in AD-like mice was analyzed by assessing organ weight, serum IgE and inflammatory cytokine levels, and histopathological changes using immunohistochemical and immunofluorescent staining.

KEY FINDINGS

In HaCaT cells, UDCA significantly diminished TARC, MDC, MCP-1, and IL-6 expression by inhibiting the phosphorylation of nuclear NF-κB and cytoplasmic IκB, and also increased the levels of skin barrier protein. In RBL-2H3 cells, UDCA reduced β-hexosaminidase and IL-4 levels. In AD-like mice, UDCA suppressed organ hypertrophy, ear edema, SCORAD index, DFE-specific IgE levels, inflammatory cytokine levels, skin hypertrophy, mast cell invasion, skin barrier loss, and thymic stromal lymphopoietin-positive areas.

SIGNIFICANCE

UDCA suppressed the expression of pro-inflammatory cytokines by keratinocytes and mast cells. It also alleviated atopy by suppressing symptoms without organ toxicity in AD-like mice. UDCA may be an effective and safe treatment for AD.

Effect of abrocitinib on skin biomarkers in patients with moderate-to-severe atopic dermatitis

BACKGROUND

This is the first report on the effects of abrocitinib, a Janus kinase 1-selective inhibitor, on the expression of skin biomarkers in patients with moderate-to-severe atopic dermatitis (AD).

METHODS

JADE MOA (NCT03915496) was a double-blind Phase 2a trial. Adults were randomly assigned 1:1:1 to receive monotherapy with once-daily abrocitinib 200 mg, abrocitinib 100 mg, or placebo for 12 weeks. The primary endpoint was change from baseline in markers of inflammation (matrix metalloproteinase [MMP]-12), epidermal hyperplasia (keratin-16 [KRT16]), T-helper 2 (Th2) immune response (C-C motif chemokine ligand [CCL]17, CCL18, and CCL26), and Th22 immune response (S100 calcium binding protein A8, A9, and A12 [S100A8, S100A9, and S100A12]) in skin through 12 weeks.

RESULTS

A total of 46 patients received abrocitinib 200 mg (n = 14), abrocitinib 100 mg (n = 16), or placebo (n = 16). Abrocitinib improved AD clinical signs and reduced itch. Gene expression of MMP-12, KRT16, S100A8, S100A9, and S100A12 was significantly decreased from baseline with abrocitinib 200 mg (at Weeks 2, 4, and 12) and abrocitinib 100 mg (at Weeks 4 and 12) in a dose-dependent manner. Abrocitinib 200 mg resulted in significant decreases from baseline in CCL17 expression at Week 12 and CCL18 expression at Weeks 2, 4, and 12; no significant decreases were observed for CCL26.

CONCLUSIONS

Alongside improvements in clinical signs and symptoms of AD, 12 weeks of abrocitinib treatment resulted in downregulation of genes associated with inflammation, epidermal hyperplasia, and Th2 and Th22 immune responses in the skin of patients with moderate-to-severe AD.

A randomized double-blind clinical trial: Comparison of oclacitinib with a traditional Chinese herbal medicine product (Dihuang Guiqin capsule) in the treatment of canine atopic dermatitis

Canine atopic dermatitis (cAD) is a common chronic inflammatory skin disease, which seriously affects the quality of life for both dogs and their owners. Currently, the common therapeutic drugs in the clinic have disadvantages such as obvious adverse effects and high prices. Traditional Chinese herbal medicine (TCHM) has great potential for the treatment of cAD. The aim of this study is to compare the effects of different doses of the TCHM product (Dihuang Guiqin capsule) and oclacitinib in the treatment of cAD through a randomized, double-blind trial. Sixty dogs diagnosed with AD were randomly and evenly divided into four groups (n = 15). The TCHM treatment group consisted of three subgroups that received three different oral doses (20, 40, and 60 mg/kg BW), while the control group received 0.5 mg/kg BW of oclacitinib. Each group was administered twice daily for 14 consecutive days. The results showed that both TCHM and oclacitinib significantly improved cAD-induced itching (evaluated by pVAS) and skin lesions (evaluated by CADESI-04), while interleukin 31 (IL-31) concentrations decreased significantly (P < 0.05) and serum biochemical indicators returned to normal. In particular, The therapeutic effects of TCHM medium- and high-dose groups were similar to those of oclacitinib (P > 0.05). The preliminary recommended dose of Dihuang Guiqin capsule for the treatment of cAD has been determined to be 40-60 mg/kg BW twice daily for 14 consecutive days, which can be reduced to once daily as appropriate. Dihuang Guiqin capsule was safe and well tolerated, which may be a new option for the treatment of cAD.

Superoxide Dismutase-Mimetic Polyphenol-Based Carbon Dots for Multimodal Bioimaging and Treatment of Atopic Dermatitis

Polyphenols have been investigated for their potential to mitigate inflammation in the context of atopic dermatitis (AD). In this study, epigallocatechin-3-gallate (EGCG)-based carbon dots (EGCG@CDs) were developed to enhance transdermal penetration, reduce inflammation, recapitulate superoxide dismutase (SOD) activity, and provide antimicrobial effects for AD treatment. The water-soluble EGCG@CDs in a few nanometers size exhibit a negative zeta potential, making them suitable for effective transdermal penetration. The fluorescence properties, including an upconversion effect, make EGCG@CDs suitable imaging probes for both in vitro and in vivo applications. By mimicking the SOD enzyme, EGCG@CDs scavenge reactive oxygen species (ROS) and actively produce hydrogen peroxide through a highly catalytic capability toward the oxygen reduction reaction, resulting in the inhibition of bacterial growth. The enhanced antioxidant properties, high charge mobility, and various functional groups of EGCG@CDs prove effective in reducing intracellular ROS in an in vitro AD model. In the mouse AD model, EGCG@CDs incorporated into a hydrogel actively penetrated the epidermal layer, leading to ROS scavenging, reduced mast cell activation, and histological recovery of skin barriers. This research represents the versatile potential of EGCG@CDs in addressing AD and advancing tissue engineering.

Atopic dermatitis: Pathophysiology, microbiota, and metabolome - A comprehensive review

Atopic dermatitis (AD) is a prevalent inflammatory skin condition that commonly occurs in children. Genetics, environment, and defects in the skin barrier are only a few of the factors that influence how the disease develops. As human microbiota research has advanced, more scientific evidence has shown the critical involvement of the gut and skin bacteria in the pathogenesis of atopic dermatitis. Microbiome dysbiosis, defined by changed diversity and composition, as well as the development of pathobionts, has been identified as a potential cause for recurring episodes of atopic dermatitis. Gut dysbiosis causes "leaky gut syndrome" by disrupting the epithelial lining of the gut, which allows bacteria and other endotoxins to enter the bloodstream and cause inflammation. The same is true for the disruption of cutaneous homeostasis caused by skin dysbiosis, which enables bacteria and other pathogens to reach deeper skin layers or even systemic circulation, resulting in inflammation. Furthermore, it is now recognized that the gut and skin microbiota releases both beneficial and toxic metabolites. Here, this review covers a range of topics related to AD, including its pathophysiology, the microbiota-AD connection, commonly used treatments, and the significance of metabolomics in AD prevention, treatment, and management, recognizing its potential in providing valuable insights into the disease.

Microbiome modulators for atopic eczema: a systematic review of experimental and investigational therapeutics

INTRODUCTION

Atopic dermatitis (AD) is a common inflammatory cutaneous disease that arises due to dysregulation of the Th2 immune response, impaired skin barrier integrity, and dysbiosis of the skin and gut microbiota. An abundance of Staphylococcus aureus biofilms in AD lesions increases the Th2 immune response, and gut bacteria release breakdown products such as Short Chain Fatty Acids that regulate the systemic immune response.

AREAS COVERED

We aim to evaluate therapies that modulate the microbiome in humans and discuss the clinical implications of these treatments. We performed a review of the literature in which 2,673 records were screened, and describe the findings of 108 studies that were included after full-text review. All included studies discussed the effects of therapies on the human microbiome and AD severity. Oral probiotics, topical probiotics, biologics, and investigational therapies were included in our analysis.

EXPERT OPINION

Oral probiotics demonstrate mixed efficacy at relieving AD symptoms. Topical probiotics reduce S. aureus abundance in AD lesional skin, yet for moderate-severe disease, these therapies may not reduce AD severity scores to the standard of biologics. Dupilumab and tralokinumab target key inflammatory pathways in AD and modulate the skin microbiome, further improving disease severity.

Integrated plasma metabolomic and cytokine analysis reveals a distinct immunometabolic signature in atopic dermatitis

Importance

Disease models for atopic dermatitis (AD) have primarily focused on understanding underlying environmental, immunologic, and genetic etiologies. However, the role of metabolic mechanisms in AD remains understudied.

Objective

To investigate the circulating blood metabolomic and cytokine profile of AD as compared to healthy control patients.

Design

This study collected plasma from 20 atopic dermatitis with moderate-to-severe itch (score of ≥5 on the itch Numeric Rating Scale and IGA score ≥3) and 24 healthy control patients. Mass-spectrometry based metabolite data were compared between AD and healthy controls. Unsupervised and supervised machine learning algorithms and univariate analysis analyzed metabolic concentrations. Metabolite enrichment and pathway analyses were performed on metabolites with significant fold change between AD and healthy control patients. To investigate the correlation between metabolites levels and cytokines, Spearman's rank correlation coefficients were calculated between metabolites and cytokines.

Setting

Patients were recruited from the Johns Hopkins Itch Center and dermatology outpatient clinics in the Johns Hopkins Outpatient Center.

Participants

The study included 20 atopic dermatitis patients and 24 healthy control patients.

Main outcomes and measures

Fold changes of metabolites in AD vs healthy control plasma.

Results

In patients with AD, amino acids isoleucine, tyrosine, threonine, tryptophan, valine, methionine, and phenylalanine, the amino acid derivatives creatinine, indole-3-acrylic acid, acetyl-L-carnitine, L-carnitine, 2-hydroxycinnamic acid, N-acetylaspartic acid, and the fatty amide oleamide had greater than 2-fold decrease (all P-values<0.0001) compared to healthy controls. Enriched metabolites were involved in branched-chain amino acid (valine, leucine, and isoleucine) degradation, catecholamine biosynthesis, thyroid hormone synthesis, threonine metabolism, and branched and long-chain fatty acid metabolism. Dysregulated metabolites in AD were positively correlated cytokines TARC and MCP-4 and negatively correlated with IL-1a and CCL20.

Conclusions and relevance

Our study characterized novel dysregulated circulating plasma metabolites and metabolic pathways that may be involved in the pathogenesis of AD. These metabolic pathways serve as potential future biomarkers and therapeutic targets in the treatment of AD.

Antihistamine and Wound Healing Potential of Gold Nanoparticles Synthesized Using Bulbine frutescens (L.) Willd

Background

Atopic dermatitis (eczema) is an inflammatory skin condition with synthetic treatments that induce adverse effects and are ineffective. One of the proposed causes for the development of the condition is the outside-in hypothesis, which states that eczema is caused by a disruption in the skin barrier. These disruptions include developing dry cracked skin, which promotes the production of histamine. Bulbine frutescens (BF) is traditionally used to treat wounds and eczema; however, limited research has been conducted to scientifically validate this. Furthermore, gold nanoparticles (AuNPs) have been used to repair damaged skin; however, no research has been conducted on AuNPs synthesized using BF.

Purpose

The study aimed to determine whether BF alleviated skin damage through wound healing, reducing the production of histamine and investigate whether AuNPs synthesized using BF would enhance biological activity.

Methods

Four extracts and four synthesized AuNPs were prepared using BF and their antiproliferative and wound healing properties against human keratinocyte cells (HaCaT) were evaluated. Thereafter, the selected samples antiproliferative activity and antihistamine activity against phorbol 12-myristate 13-acetate (PMA) stimulated granulocytes were evaluated.

Results

Of the eight samples, the freeze-dried leaf juice (BFE; p < 0.01) extract and its AuNPs (BFEAuNPs; p < 0.05) displayed significant wound closure at 100 µg/mL and were further evaluated. The selected samples displayed a fifty percent inhibitory concentration (IC50) of >200 µg/mL against PMA stimulated granulocytes. Compared to the untreated (media with PMA) control (0.30 ± 0.02 ng/mL), BFEAuNPs significantly inhibited histamine production at a concentration of 100 (p < 0.01) and 50 µg/mL (p < 0.001).

Conclusion

BFE and BFEAuNPs stimulated wound closure, while BFEAuNPs significantly inhibited histamine production. Further investigation into BFEAuNPs in vivo wound healing activity and whether it can target histamine-associated receptors on mast cells as a potential mechanism of action should be considered.

New Insights into Mechanisms Traditional Chinese Medicine for Allergic Rhinitis by Regulating Inflammatory and Oxidative Stress Pathways

Allergy rhinitis (AR) is becoming more common and has serious medical and societal consequences. Sneezing, paroxysmal nasal blockage, nasal itching, mucosal edema, coughing, and rhinorrhea are symptoms of this type I allergic immunological illness. Immunoglobulin E-mediated inflammation is the cause of it. Because AR is prone to recurrent attacks, extended medication therapy may impair its effectiveness. In addition to negatively affecting the patients' physical health, this can also negatively impact their mental health. During AR development, there are inflammatory and oxidative stress responses that are linked to problems in a number of signal transduction pathways. By using the terms "allergic rhinitis", "traditional Chinese medicine", "inflammation", and "oxidative stress", we screened for pertinent research published over the previous five years in databases like PubMed. We saw that NF-KB, TLR, IL-33/ST2, PI3K/AKT, MAPK, and Nrf2 are some of the most important inflammatory and oxidative stress pathways in AR. Studies have revealed that antioxidant and anti-inflammatory therapy reduced the risk of AR and was therapeutic; however, the impact of the therapy varies widely. The Chinese medical system places a high value on traditional Chinese medicine (TCM), which has been there for virtually all of China's 5000-year history. By influencing signaling pathways related to inflammation and oxidative stress, Chinese herbal medicine and its constituent compounds have been shown to prevent allergic rhinitis. This review will focus on this evidence and provide references for clinical treatment and scientific research applications.

Epigenetic control of inflammation in Atopic Dermatitis

Atopic dermatitis (AD), also known as atopic eczema, is a common but also complex chronic, itchy skin condition with underlying inflammation of the skin. This skin ailment is prevalent worldwide and affects people of all ages, particularly children below five years of age. The itching and resulting rashes in AD patients are often the result of inflammatory signals, thus necessitating a closer look at the inflammation-regulating mechanisms for putative relief, care and therapy. Several chemical- as well as genetically-induced animal models have established the importance of targeting pro-inflammatory AD microenvironment. Epigenetic mechanisms are gaining attention towards a better understanding of the onset as well as the progression of inflammation. Several physiological processes with implications in pathophysiology of AD, such as, barrier dysfunction either due to reduced filaggrin / human β-defensins or altered microbiome, reprograming of Fc receptors with resulting overexpression of high affinity IgE receptors, elevated eosinophil numbers or the elevated IL-22 production by CD4 + T cells have underlying epigenetic mechanisms that include differential promoter methylation and/or regulation by non-coding RNAs. Reversing these epigenetic changes has been verified to reduce inflammatory burden through altered secretion of cytokines IL-6, IL-4, IL-13, IL-17, IL-22 etc, with benefit against AD progression in experimental models. A thorough understanding of epigenetic remodeling of inflammation in AD has the potential of opening avenues for novel diagnostic, prognostic and therapeutic options.

Understanding Type 3 Innate Lymphoid Cells and Crosstalk with the Microbiota: A Skin Connection

Innate lymphoid cells (ILCs) are a diverse population of lymphocytes classified into natural killer (NK) cells, ILC1s, ILC2s, ILC3s, and ILCregs, broadly following the cytokine secretion and transcription factor profiles of classical T cell subsets. Nonetheless, the ILC lineage does not have rearranged antigen-specific receptors and possesses distinct characteristics. ILCs are found in barrier tissues such as the skin, lungs, and intestines, where they play a role between acquired immune cells and myeloid cells. Within the skin, ILCs are activated by the microbiota and, in turn, may influence the microbiome composition and modulate immune function through cytokine secretion or direct cellular interactions. In particular, ILC3s provide epithelial protection against extracellular bacteria. However, the mechanism by which these cells modulate skin health and homeostasis in response to microbiome changes is unclear. To better understand how ILC3s function against microbiota perturbations in the skin, we propose a role for these cells in response to Cutibacterium acnes, a predominant commensal bacterium linked to the inflammatory skin condition, acne vulgaris. In this article, we review current evidence describing the role of ILC3s in the skin and suggest functional roles by drawing parallels with ILC3s from other organs. We emphasize the limited understanding and knowledge gaps of ILC3s in the skin and discuss the potential impact of ILC3-microbiota crosstalk in select skin diseases. Exploring the dialogue between the microbiota and ILC3s may lead to novel strategies to ameliorate skin immunity.

Upadacitinib treatment in a real-world difficult-to-treat atopic dermatitis patient cohort

BACKGROUND

Upadacitinib was the first JAK-1 selective inhibitor registered for the treatment of moderate-to-severe atopic dermatitis (AD). Although efficacy and safety have been shown in clinical trials, real-world data on the use of upadacitinib in patients that have been treated with other immunosuppressants and targeted therapies is limited.

OBJECTIVES

To provide real-world evidence on the use of upadacitinib treatment in moderate-to-severe atopic dermatitis.

METHODS

In this prospective observational single-centre study, all AD patients treated with upadacitinib treatment in the context of standard care were included between August 2021 and September 2022. Clinical outcome measures and adverse events (AEs) were analysed.

RESULTS

Forty-eight patients were included. The majority (n = 39; 81%) had failed (ineffectiveness) on other targeted therapies, including other JAK inhibitors and biologics. Thirty-four (71%) patients were still using upadacitinib treatment at last follow up (median duration 46.5 weeks). Fourteen (29%) patients discontinued treatment due to ineffectiveness or AE. Upadacitinib treatment led to a significant decrease of disease severity during a median follow up of 37.5 weeks. Median IGA at baseline decreased from 3 (IQR 2-3) to 1.5 (IQR 1-2) at last review (p < 0.001). Median NRS itch decreased from 7 (IQR 5-8) at baseline to 2.25 (IQR 0.25-6.5) at last review (p < 0.001). Three patients discontinued treatment due to AE. Forty-eight AEs were reported, including acne-like eruptions (25%), nausea (13%) and respiratory tract infections (10%).

CONCLUSIONS

In this real-world cohort, we confirmed that upadacitinib is an effective treatment in a subset of AD patients that have failed several previous systemic immunosuppressive and biologic treatments. Overall, AE were mostly well tolerated and not a reason to discontinue treatment for most patients.