Microneedles: A novel clinical technology for evaluating skin characteristics.

BACKGROUND: Current methods for evaluating efficacy of cosmetics have limitations because they cannot accurately measure changes in the dermis. Skin sampling using microneedles allows identification of skin-type biomarkers, monitoring treatment for skin inflammatory diseases, and evaluating efficacy of anti-aging and anti-pigmentation products. MATERIALS AND METHODS: Two studies were conducted: First, 20 participants received anti-aging treatment; second, 20 participants received anti-pigmentation treatment. Non-invasive devices measured skin aging (using high-resolution 3D-imaging in the anti-aging study) or pigmentation (using spectrophotometry in the anti-pigmentation study) at weeks 0 and 4, and adverse skin reactions were monitored. Skin samples were collected with biocompatible microneedle patches. Changes in expression of biomarkers for skin aging and pigmentation were analyzed using qRT-PCR. RESULTS: No adverse events were reported. In the anti-aging study, after 4 weeks, skin roughness significantly improved in 17 out of 20 participants. qRT-PCR showed significantly increased expression of skin-aging related biomarkers: PINK1 in 16/20 participants, COL1A1 in 17/20 participants, and MSN in 16/20 participants. In the anti-pigmentation study, after 4 weeks, skin lightness significantly improved in 16/20 participants. qRT-PCR showed significantly increased expression of skin-pigmentation-related biomarkers: SOD1 in 15/20 participants and Vitamin D Receptor (VDR) in 15/20 participants. No significant change in TFAP2A was observed. CONCLUSION: Skin sampling and mRNA analysis for biomarkers provides a novel, objective, quantitative method for measuring changes in the dermis and evaluating the efficacy of cosmetics. This approach complements existing evaluation methods and has potential application in assessing the effectiveness of medical devices, medications, cosmeceuticals, healthy foods, and beauty devices.

Minimally invasive skin sampling and transcriptome analysis using microneedles for skin type biomarker research.

BACKGROUND: Minimally invasive skin sampling is used in various fields. In this study, we examined whether it was possible to obtain skin specimens using biocompatible microneedles composed of sodium hyaluronate and performed transcriptome analysis. MATERIALS AND METHODS: Thirty-three subjects with different skin conditions, such as skin aging, skin hydration, skin pigmentation, oily skin and sensitive skin, were recruited. Skin types were evaluated based on age, non-invasive measurement devices, 10% lactic acid stinging test and visual assessment; the skin specimens were sampled from the face using microneedles. Total RNA was extracted, and microarray was performed. Correlations between various biomarkers and skin condition parameters were analysed. RESULTS: Several skin-type biomarkers are correlated with age, non-invasive device measurements, LAST score and visual assessment of acne lesions. Representatively, COL1A1 (Collagen type 1 alpha 1 chain), FN1 (Fibronectin 1) and PINK1 (PTEN-induced putative kinase protein 1) for skin aging, FLG (Filaggrin), KLF4 (Kruppel-like factor 4) and LOR (Loricrin) for skin hydration, GPNMB (Glycoprotein non-metastatic melanoma protein B), MLANA (Melan-A) and TYR (Tyrosinase) for skin pigmentation, IGF1 (insulin-like growth factor-1), MPZL3 (Myelin protein zero like 3) and AQP3 (Aquaporin 3) for oily skin and PGF (placental growth factor), CYR61 (cysteine-rich angiogenic inducer 61), RBP4 (retinol-binding protein 4), TAC1 (Tachykinin precursor 1), CAMP (Cathelicidin antimicrobial peptide), MMP9 (Matrix metallopeptidase 9), MMP3, MMP12 and CCR1 (C-C motif chemokine receptor 1) for sensitive skin. CONCLUSION: Microneedle skin sampling is a new and minimally invasive option for transcriptome analysis of human skin and can be applied for diagnosis and treatment efficacy evaluation, as well as skin type classification.

Skin-resident natural killer T cells participate in cutaneous allergic inflammation in atopic dermatitis.

BACKGROUND: Natural killer T (NKT) cells are unconventional T cells that bridge innate and adaptive immunity. NKT cells have been implicated in the development of atopic dermatitis (AD). OBJECTIVE: We aimed to investigate the role of NKT cells in AD development, especially in skin. METHODS: Global proteomic and transcriptomic analyses were performed by using skin and blood from human healthy-controls and patients with AD. Levels of CXCR4 and CXCL12 expression in skin NKT cells were analyzed in human AD and mouse AD models. By using parabiosis and intravital imaging, the role of skin CXCR4+ NKT cells was further evaluated in models of mice with AD by using CXCR4-conditionally deficient or CXCL12 transgenic mice. RESULTS: CXCR4 and its cognate ligand CXCL12 were significantly upregulated in the skin of humans with AD by global transcriptomic and proteomic analyses. CXCR4+ NKT cells were enriched in AD skin, and their levels were consistently elevated in our models of mice with AD. Allergen-induced NKT cells participate in cutaneous allergic inflammation. Similar to tissue-resident memory T cells, the predominant skin NKT cells were CXCR4+ and CD69+. Skin-resident NKT cells uniquely expressed CXCR4, unlike NKT cells in the liver, spleen, and lymph nodes. Skin fibroblasts were the main source of CXCL12. CXCR4+ NKT cells preferentially trafficked to CXCL12-rich areas, forming an enriched CXCR4+ tissue-resident NKT cells/CXCL12+ cell cluster that developed in acute and chronic allergic inflammation in our models of mice with AD. CONCLUSIONS: CXCR4+ tissue-resident NKT cells may form a niche that contributes to AD, in which CXCL12 is highly expressed.

Identification of skin aging biomarkers correlated with the biomechanical properties.

BACKGROUND: Skin aging can be described as a combination of intrinsic and extrinsic aging. Various parameters for evaluating skin characteristics have been proposed. However, an accurate biomarker for skin aging and the relationship between biomarkers and biomechanical parameters of the skin is yet to be explored. MATERIALS AND METHODS: This study included 20 subjects by age. Skin aging was measured using non-invasive devices. Skin tissues were acquired through punch biopsy for immunohistochemistry and qRT-PCR of skin aging biomarkers, and analyzed correlation both, validated their use. RESULTS: Biomechanical properties of skin aging decreased with age. Among the biomarkers previously reported, we found that the expression of Moesin, TXNDC5, RhoGDI, and RSU1 decreased, while that of Vimentin and FABP5 increased with age. Pearson correlation showed that the expression levels of TXNDC5, RhoGDI, RSU1, and Vimentin were significantly correlated with the results of non-invasive measurements. In addition, the expression of TXNDC5, RhoGDI, and RSU1 increased, while that of Vimentin decreased, in skin explants upon treatment with one of the anti-aging compounds, retinoic acid. CONCLUSION: From this study, we identified practical molecular biomarkers of skin aging, TXNDC5, RhoGDI, RSU1, and Vimentin, which correlated with the skin biomechanical properties of skin aging.

Chitinase 3-like 1 drives allergic skin inflammation via Th2 immunity and M2 macrophage activation.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by defective skin barrier and Th2 immune responses. Chitinase 3-like 1 (CHI3L1), also known as breast regression protein 39 (BRP-39) in mice and human homologue YKL-40, plays important roles in Th2 inflammation and allergen sensitization. CHI3L1 has been implicated in a variety of diseases including asthma characterized by inflammation, apoptosis and tissue remodelling, but its role in AD remains elusive. OBJECTIVE: The aim of this study was to investigate the role of CHI3L1 in the development and progression of AD. RESULTS: We investigated YKL-40 levels in the serum and skin of AD patients by ELISA and immunofluorescence, respectively. Using a murine model of AD induced by ovalbumin (OVA), we investigated Th2 immune responses, M2 macrophage activation and skin barrier gene expression using wild-type (WT) and BRP-39 null mutant (BRP-39-/- ) mice. YKL-40 level was significantly increased in serum of AD patients. In addition, both mRNA and protein expression levels of BRP-39 were higher in OVA-sensitized WT mice than in control mice. OVA-sensitized BRP-39-/- mice showed decreased epidermal thickness, lower total serum IgE, Th2 cytokine levels and CD4+ effector T cell populations than OVA-sensitized WT mice. Induction of BRP-39 was dominant in dermal macrophages. BRP-39 deficiency was found to be involved in M2 macrophage activation. Consistently, the YKL-40 level in the skin of AD patients was higher than in normal subjects and it was expressed in dermal macrophages. BRP-39 deficiency attenuated dysregulation of skin barrier and tight junction genes. CONCLUSIONS AND CLINICAL RELEVANCE: These findings demonstrate that CHI3L1 mediates the development of AD induced by OVA, affecting Th2 inflammation, M2 macrophage activation and skin barrier function.

5 nm Silver Nanoparticles Amplify Clinical Features of Atopic Dermatitis in Mice by Activating Mast Cells.

The triggering effect of silver nanoparticles (NPs) on the induction of allergic reactions is evaluated, by studying the activation of mast cells and the clinical features of atopic dermatitis in a mouse model. Granule release is induced in RBL-2H3 mast cells by 5 nm, but not 100 nm silver NPs. Increases in the levels of reactive oxygen species (hydrogen peroxide and mitochondrial superoxide) and intracellular Ca++ in mast cells are induced by 5 nm silver NPs. In a mouse model of atopic dermatitis induced by a mite allergen, the skin lesions are more severe and appear earlier in mice treated simultaneously with 5 nm silver NPs and allergen compared with mice treated with allergen alone or 100 nm silver NPs and allergen. The histological findings reveal that number of tryptase-positive mast cells and total IgE levels in the serum increase in mice treated with 5 nm silver NPs and allergen. The results in this study indicate that cotreatment with 5 nm silver NPs stimulates mast cell degranulation and induces earlier and more severe clinical alterations in allergy-prone individuals.

Thymic stromal lymphopoietin regulates eosinophil migration via phosphorylation of l-plastin in atopic dermatitis.

Infiltration of eosinophils in atopic dermatitis (AD), which contains inflammatory molecules and cytokines, recruits more inflammatory cells and causes further skin damage. Thymic stromal lymphopoietin (TSLP) is an epithelial cytokine that induces the proinflammatory Th2 immune response and plays an important role in allergic disease. In this study, we aimed to identify a novel protein that regulates TSLP in eosinophils to further understand the role of eosinophils in atopic dermatitis. Using a proteomics approach, we identified the TSLP-inducible protein l-plastin and confirmed upregulation of l-plastin and p-l-plastin in TSLP-treated human eosinophilic leukaemic (EoL-1) cells and in eosinophils from AD patients. Migration assays showed that migration of eosinophils increased when cells were treated with TSLP and when cells were treated with TSLP and an additional cytokine such as interleukin (IL)-3, IL-4, IL-5 or IL-13, when compared to migration of untreated eosinophils. We also confirmed a positive correlation between phosphorylation of l-plastin and an increase in migration of TSLP and cytokine-treated eosinophils. In addition, phosphorylation of l-plastin was sensitive to PKCßII inhibition. Our results suggest that TSLP-induced phosphorylation of l-plastin affects eosinophil migration, which may be mediated by the protein kinase C signalling pathway in atopic dermatitis, thus suggesting p-l-plastin as a potential drug target for eosinophil-targeted allergy therapy.

Positive reactions to nickel on a patch test do not predict clinical outcome of nickel alloy-based atrial septal defect occluder implantation.

BACKGROUND: Patch testing is thought to be necessary prior to metal device implantation to rule out metal allergy-related complications; however, there are controversies over the effects of nickel allergy on the outcome of nickel alloy-based device implantation. OBJECTIVE: This study aimed to evaluate the adverse events in a Korean population of nickel allergy patients who underwent atrial septal defect (ASD) closure with a nickel-titanium alloy-based device. METHODS: We retrospectively reviewed the medical records of patients who underwent ASD closure with a nitinol device. RESULTS: Among 38 patients who had ASD closure, 4 of 5 nickel-allergic patients and 10 of the 33 non-nickel-allergic patients had post-closure complications. All patients fared well, without device failure culminating in device removal. CONCLUSION: In this study, positive reactions to nickel in a patch test were not associated with adverse early or late outcomes following ASD closure with a nickel alloy-based device.

Head and neck dermatitis is exacerbated by Malassezia furfur colonization, skin barrier disruption, and immune dysregulation.

Introduction & objectives: Head and neck dermatitis (HND) is a refractory phenotype of atopic dermatitis (AD) and can be a therapeutic challenge due to lack of responsiveness to conventional treatments. Previous studies have suggested that the microbiome and fungiome may play a role in inducing HND, but the underlying pathogenic mechanisms remain unknown. This study aimed to determine the link between HND and fungiome and to examine the contribution of Malassezia furfur. Materials and methods: To identify the effect of the sensitization status of M. furfur on HND, 312 patients diagnosed with AD were enrolled. To elucidate the mechanism underlying the effects of M. furfur, human keratinocytes and dermal endothelial cells were cultured with M. furfur and treated with Th2 cytokines. The downstream effects of various cytokines, including inflammation and angiogenesis, were investigated by real-time quantitative PCR. To identify the association between changes in lipid composition and M. furfur sensitization status, D-squame tape stripping was performed. Lipid composition was evaluated by focusing on ceramide species using liquid chromatography coupled with tandem mass spectrometry. Results: Increased sensitization to M. furfur was observed in patients with HND. Additionally, sensitization to M. furfur was associated with increased disease severity in these patients. IL-4 treated human keratinocytes cultured with M. furfur produced significantly more VEGF, VEGFR, IL-31, and IL-33. IL-4/M. furfur co-cultured dermal endothelial cells exhibited significantly elevated VEGFR, TGF-ß, TNF-α, and IL-1ß levels. Stratum corneum lipid analysis revealed decreased levels of esterified omega-hydroxyacyl-sphingosine, indicating skin barrier dysfunction in HND. Finally, M. furfur growth was inhibited by the addition of these ceramides to culture media, while the growth of other microbiota, including Cutibacterium acnes, were not inhibited. Conclusions: Under decreased levels of ceramide in AD patients with HND, M. furfur would proliferate, which may enhance pro-inflammatory cytokine levels, angiogenesis, and tissue remodeling. Thus, it plays a central role in the pathogenesis of HND in AD.

FABP5 as a possible biomarker in atopic march: FABP5-induced Th17 polarization, both in mouse model and human samples.

BACKGROUND: While the incidence of patients with atopic dermatitis (AD) with atopic march (AM) showing respiratory allergy is steadily rising, the pathomechanism is still unknown. There are currently no biomarkers to predict progression of AM. METHODS: To explore the mechanism of AM, patients with AD and AM and healthy controls were recruited and RNA microarray, flow cytometry, quantitative real-time polymerase chain reaction, and immunofluorescence staining were performed. We also co-cultured dendritic cells and CD4+T cells with various Dermatophagoides farinae allergen fractions. Cytokine levels were evaluated using enzyme-linked immunosorbent assay. FINDINGS: Both fatty-acid-binding protein 5 (FABP5) and Th17-related genes were more highly expressed in AM. FABP5 knockdown significantly decreased Th17-inducing cytokines in keratinocytes and IL-17A in T cells from AM patients. Further confirmation was obtained using an AM mice model compared to mice without AM. Der f 1, a major D. farinae allergen, increased FABP5 and IL-17A expression in T cells from AM patients. Higher serum FABP5 levels from AM patients were positively correlated with serum IL-17A levels. INTERPRETATION: FABP5 expression, possibly enhanced by higher epicutaneous and respiratory sensitization to Der f 1, may directly promote Th17 responses in AD patients with AM. Thus, AM progression can be explained by Th17 reaction induced by FABP5. FABP5 was identified as a potential biomarker in AM. FUNDING: This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Science and ICT; No. NRF-2017R1A2B4009568), grants of the Korean Health Technology R&D Project, Ministry for Health, Welfare & Family Affairs, and the Republic of Korea (HI13C0010, HI14C1324, HI14C1799).

ZAG Regulates the Skin Barrier and Immunity in Atopic Dermatitis.

Adipokines modulate immune responses and lipid metabolism in allergic disease; however, little is known about their role in the skin barrier and atopic dermatitis (AD). We identified ZAG, an adipokine that regulates lipid mobilization, as a biomarker for AD. ZAG levels were consistently decreased in sera, T cells, and skin in human AD patients compared with healthy controls. ZAG was primarily detected in the stratum corneum along with FLG and LOR. Knockdown of ZAG with short hairpin RNA resulted in decreased FLG and increased TSLP. Topical ZAG treatment in AD mice recovered ZAG expression in the skin and improved AD-like symptoms, transepidermal water loss, and ceramide levels. Furthermore, topical ZAG treatment induced immunoregulatory effects, including reduction of IL-4, IL-17, and IFN-γ and increased Foxp3 in the skin and lymphoid organs. Interestingly, ZAG treatment also recovered decreased levels of ADAM17, an important player in skin barrier function and immune response in AD. Thus, ZAG deficiency is closely related to skin barrier function and the immune abnormalities of AD, and we suggest that restoration of ZAG may be a promising therapeutic option for the treatment of AD.

Particulate matter induces inflammatory cytokine production via activation of NFκB by TLR5-NOX4-ROS signaling in human skin keratinocyte and mouse skin.

Particulate matter (PM) increases levels of pro-inflammatory cytokines, but its effects on the skin remain largely unknown. We investigated the signal transduction pathway and epigenetic regulatory mechanisms underlying cellular inflammation induced by PM with a diameter of ≤ 2.5 (PM2.5) in vitro and in vivo. PM2.5-treated skin keratinocytes produced various inflammatory cytokines, including IL-6. The binding of PM2.5 to TLR5 initiated intracellular signaling through MyD88, and led to the translocation of NFκB to the nucleus, where it bound the NFκB site within IL-6 promoter. Furthermore, PM2.5 induced a direct interaction between TLR5 and NOX4, and in turn induced the production of ROS and activated NFκB-IL-6 downstream, which was prevented by siRNA-mediated knockdown of NOX4 or antioxidant treatment. Furthermore, expression of TLR5, MyD88, NOX4, phospho-NFκB, and IL-6 was increased in skin tissue of PM2.5-treated flaky tail mice. PM2.5-induced increased transcription of IL-6 was regulated via DNA methylation and histone methylation by epigenetic modification; the binding of DNA demethylase and histone methyltransferase to the IL-6 promoter regions resulted in increased IL-6 mRNA expression. Our findings provide deep insight into the pathogenesis of PM2.5 exposure and can be used as a therapeutic strategy to treat inflammatory skin diseases caused by PM2.5 exposure.

Activated Leukocyte Cell Adhesion Molecule Modulates Th2 Immune Response in Atopic Dermatitis.

PURPOSE: Activated leukocyte cell adhesion molecule (ALCAM), a member of the immunoglobulin superfamily, is highly expressed on dendritic cells. ALCAM and its receptor CD6 are co-stimulatory molecules in the immunological synapse; their interaction is required for T cell activation. While atopic dermatitis (AD) is recognized as a T helper 2 (Th2)-mediated allergic disease, the role of ALCAM in its pathogenesis is unclear. METHODS: ALCAM levels were measured in the serum of AD patients and AD-induced murine model by ovalbumin treatment. We next investigated transepidermal water loss, clinical score, Th2-immune responses, skin barrier gene expression and T-cell activation using wild-type (WT) and ALCAM deficiency mice. An oxazolone-induced AD-like model was also established and analyzed using WT- and ALCAM-deficient mice. RESULTS: We found that serum ALCAM levels were elevated in pediatric AD patients as well as WT AD mice, whereas Th2-type cytokine production and AD symptoms were suppressed in ALCAM-deficient mice. In addition, CD4⁺ effector T-cell counts in murine skin and skin-draining lymph nodes were lower in ALCAM-deficient mice than in their WT counterparts. ALCAM deficiency was also linked to higher expression of skin barrier genes and number of lamellar bodies. CONCLUSIONS: These findings indicate that ALCAM may contribute to AD pathogenesis by meditating a Th2-dominant immune response and disrupting the barrier function of the skin.

Successful transdermal allergen delivery and allergen-specific immunotherapy using biodegradable microneedle patches.

Allergen-specific immunotherapy (SIT) is an effective treatment modality for allergic diseases such as atopic dermatitis (AD). However, frequent visits over a 3-year period as well as looming adverse events tend to discourage patient compliance. Therefore, a more convenient, effective, and safe method of SIT is needed. For several decades, use of microneedles has been promoted as an efficient and precise transdermal drug delivery method. In this study, we developed Dermatophagoides farinae (D. farinae) extract (DfE)-loaded microneedle patches, and evaluated their safety and efficacy as a novel SIT method. After 4 weeks of patch application, efficient allergen delivery and successful induction of immune response to DfE were demonstrated in mice, with no apparent adverse events. AD-induced NC/Nga mice received microneedle immunotherapy (MNIT) (10 µg), subcutaneous immunotherapy (SCIT) (10 µg), SCIT (100 µg), or placebo. Both MNIT (10 µg) and SCIT (100 µg) treatments improved clinical and histologic manifestations of AD skin lesions, altered immunoglobulin production, dampened Th2 cellular response, and boosted Treg infiltrates, without significant side effects; whereas SCIT (10 µg) or placebo subsets failed to show any effects. Based on the favorable safety and efficacy profiles demonstrated in mice by MNIT in the current study, we believe that MNIT may serve as a new SIT modality.

Upregulation of CD47 in Regulatory T Cells in Atopic Dermatitis.

PURPOSE: Regulatory T (Treg) cells are key modulators in the immune system. Recent studies have shown that atopic dermatitis (AD) patients have higher numbers of Treg cells; however, little is known about the specific phenotype and function of Treg cells in AD. MATERIALS AND METHODS: To identify differentially expressed proteins in peripheral induced Treg cells in AD and naturally derived Treg cells in normal controls, CD4⁺CD25⁺ Treg cells were isolated from thymus tissue of normal mice and the spleens of AD mice. Membrane proteins were extracted, and quantitative proteomics labeling with Tandem Mass Tags (TMT) was performed, followed by one-dimensional liquid chromatography/tandem mass spectrometry analysis. RESULTS: Using TMT labeling, we identified 510 proteins, including 63 membrane proteins and 16 plasma membrane proteins. CD47 was one of the upregulated proteins in Treg cells in AD spleens. Although CD47 was expressed in all CD4⁺ and CD8⁺ T cells, a significantly higher expression of CD47 was observed in the Treg cells of AD mice and AD patients than in those of normal mice and healthy controls. Furthermore, Treg cells from the spleen showed a significantly higher expression of CD47 than those from the thymus. CONCLUSION: We found that CD47 is highly expressed in the Treg cells of AD mice, particularly in the spleen. Based on our results, we propose that CD47(high) Treg cells are likely induced Treg cells and that upregulated CD47 in the Treg cells of AD patients may play a role in the increased population of Treg cells in AD.

TSLP Is a Potential Initiator of Collagen Synthesis and an Activator of CXCR4/SDF-1 Axis in Keloid Pathogenesis.

Recently, thymic stromal lymphopoietin (TSLP), which is well studied in allergic diseases, has been reported in fibrotic diseases, including idiopathic pulmonary fibrosis and atopic dermatitis fibrosis. However, the role of TSLP in keloid is obscure. In this study, we assessed the expression of TSLP in keloid tissue and investigated the possible role of TSLP in keloid pathogenesis. We observed that TSLP expression was increased in keloid tissue compared to normal tissue. Furthermore, TSLP treatment induced increased collagen I and collagen III expression in fibroblasts via transforming growth factor-?; however, there was higher expression in keloid fibroblasts compared to normal fibroblasts. Stromal cell-derived factor-1?, which was recently reported to enhance wound healing through recruiting bone marrow-derived mesenchymal stem cells to the wound area, increased after TSLP treatment in fibroblasts and was primarily expressed in ?-smooth muscle action-positive myofibroblasts in keloid tissue. Furthermore, fibrocytes expressing CXCR4, a stromal cell-derived factor-1? receptor, were significantly increased in keloid tissue compared to normal tissue. Finally, intradermal TSLP injection on BALB/c mice increased stromal cell-derived factor-1? expression and CXCR4(+) fibrocytes infiltration. Our data suggest that TSLP is a potent inducer of collagen and transforming growth factor-? production in keloid fibroblasts. In addition, it might activate the CXCR4/stromal cell-derived factor-1 axis to increase fibrocyte infiltration into the keloid tissue.