Atopic Dermatitis Model Research Articles

Extract of Wheatgrass and Aronia Mixture Ameliorates Atopic Dermatitis-Related Symptoms by Suppressing Inflammatory Response and Oxidative Stress In Vitro and In Vivo.

Atopic dermatitis is regulated by the production of pro-inflammatory cytokines and chemokines via the nuclear factor kappa B or mitogen-activated protein kinase signaling pathways, as well as, the release of oxidative stress-related factors via the NF-E2 p45-related factor 2 signaling pathway. Both wheatgrass (Triticum aestivum L., TA) and aronia (Aronia melanocarpa, AR) are known for their anti-inflammatory and antioxidant properties, however, the anti-inflammatory and antioxidant effects of TA and AR (TAAR) mixture extract have not been elucidated in an atopic dermatitis model. In this study, we assessed the inhibitory effects and underlying molecular mechanism of TAAR extract against lipopolysaccharide-induced inflammation and tumor necrosis factor-α/interferon-γ-induced inflammation and oxidative stress in vitro. We also investigated the alleviating effect of TAAR extract on DNCB-induced atopic dermatitis-like skin lesions in mice in vivo. We found that TAAR extract treatment inhibited inflammatory mediators in both RAW 264.7 cells and HaCaT cells, and increased the expression of oxidative stress defense enzymes in HaCaT cells. Furthermore, treatment of the DNCB-induced mouse model with TAAR extract ameliorated the overall symptoms of atopic dermatitis. Therefore, TAAR extract as a novel natural therapeutic agent may be used for the treatment of atopic dermatitis.

Dual antibody inhibition of KLK5 and KLK7 for Netherton syndrome and atopic dermatitis.

The epidermis is a barrier that prevents water loss while keeping harmful substances from penetrating the host. The impermeable cornified layer of the stratum corneum is maintained by balancing continuous turnover driven by epidermal basal cell proliferation, suprabasal cell differentiation, and corneal shedding. The epidermal desquamation process is tightly regulated by balance of the activities of serine proteases of the Kallikrein-related peptidases (KLK) family and their cognate inhibitor lymphoepithelial Kazal type-related inhibitor (LEKTI), which is encoded by the serine peptidase inhibitor Kazal type 5 gene. Imbalance of proteolytic activity caused by a deficiency of LEKTI leads to excessive desquamation due to increased activities of KLK5, KLK7, and KLK14 and results in Netherton syndrome (NS), a debilitating condition with an unmet clinical need. Increased activity of KLKs may also be pathological in other dermatoses such as atopic dermatitis (AD). Here, we describe the discovery of inhibitory antibodies against murine KLK5 and KLK7 that could compensate for the deficiency of LEKTI in NS. These antibodies are protective in mouse models of NS and AD and, when combined, promote improved skin barrier integrity and reduced inflammation. To translate these findings, we engineered a humanized bispecific antibody capable of potent inhibition of human KLK5 and KLK7. A crystal structure of KLK5 bound to the inhibitory Fab revealed that the antibody binds distal to its active site and uses a relatively unappreciated allosteric inhibition mechanism. Treatment with the bispecific anti-KLK5/7 antibody represents a promising therapy for clinical development in NS and other inflammatory dermatoses.

Topical application of imatinib mesylate suppresses vitamin D3 analog-induced dermatitis in Balb/c mice.

Atopic dermatitis (AD) is an allergic disease mediated by Th2 cells. In AD, externally stimulated keratinocytes release inflammatory cytokines, such as IL-33 and TSLP. Inflammatory cells infiltrate skin tissue and increase vascular permeability. Therefore, we hypothesized that imatinib mesylate (IMT), which suppresses vascular permeability, may be a candidate therapeutic agent for AD. A vitamin D3 analog (MC903) was administered daily to both ears of Balb/c mice to create a murine AD model to which IMT was applied. The skin lesions were evaluated histopathologically and by immunostaining. Cytokine expression in the skin was assessed by using real-time polymerase chain reaction (PCR) and immunostaining and was investigated using Evans Blue to determine whether IMT suppressed vascular permeability due to histamine. The suppressive effect of TNF-α/IL-4-induced TSLP expression in primary mouse keratinocytes (MKCs) treated with IMT was then investigated. Tslp gene and protein expression in the lesion was measured using real-time PCR and ELISA. The activation of signal transduction was analysed by western blotting. Topical application of IMT significantly reduced ear thickness, Evans blue leakage, and scratch onset. IMT suppressed the number of infiltrating cells (CD4+ T cells, eosinophils, and basophils), and the expression of IL-13, IL-33, and TSLP in a MC903-induced, murine AD model and inhibited TNF-α/IL-4-induced TSLP expression via downregulation of ERK phosphorylation in MKCs. IMT reduced the skin symptoms in a MC903-induced, murine AD model, suggesting that it may have potential as a new treatment for AD.

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

BackgroundThe progression of acute-to-chronic atopic dermatitis is accompanied by multiple helper T-cell cytokine responses, but the mechanisms and relative importance of these changes remain unclear. There is no animal model for atopic dermatitis that recapitulates these cytokine responses.ObjectiveWe sought to build a novel mouse model for atopic dermatitis (AD) that recapitulates these helper T-cell responses and some dynamic changes in cytokine responses in the progression of AD.MethodsFemale BALB/c mice were subjected to the application of dinitrofluorobenzene (DNFB) and ovalbumin (OVA) to induce AD-like dermatitis. Skin lesions and serum were collected from mice in the acute and chronic phases to detect changes in cytokine responses and other features of AD.ResultsCombined application of DNFB and OVA successfully induced AD-like dermatitis and histological changes as well as epidermal barrier dysfunction. In the acute phase of AD-like dermatitis, Th2-associated cytokines were mainly increased in serum and skin lesions. In the chronic phase of AD-like dermatitis, Th2-associated cytokines were still highly expressed, while Th1- and Th17-associated cytokines were also gradually increased. Compared with the acute phase, the JAK-STAT signaling pathway was highly expressed in the chronic phase of AD-like dermatitis.ConclusionThe combined application of DNFB and OVA could be used to build a new mouse model for atopic dermatitis. This mouse model recapitulates the helper T-cell responses and some dynamic changes in cytokine responses in the progression of acute-to-chronic in human AD. The JAK-STAT signaling pathway plays a pivotal role in the chronicity of AD.

Inhibitory Effect of Oroxylin A in a Mouse Model of Atopic Dermatitis.

Scutellaria baicalensis has long been used in Asian traditional medicine to prevent and treat suppurative dermatitis, allergic diseases, inflammation, hyperlipemia, and arteriosclerosis. Oroxylin A is a flavone present in Scutellaria baicalensis. Because the root extracts of Scutellaria baicalensis have been shown to have anti-dermatitis effects, the authors investigated the effects of oroxylin A on chemically induced atopic dermatitis (AD) in an in vivo AD model induced by 1-chloro-2,4-dinitrobenzene (CDNB) in BALB/c mice. CDNB-induced skin hypertrophy and accumulation of mast cells in the epidermis and dermis were significantly decreased by oroxylin A. Increased serum levels of immunoglobulin E, as well as pro-inflammatory chemokines and cytokines in the skin and lymph nodes, were significantly decreased by oroxylin A. Suppression of immune responses in the skin and lymph nodes by oroxylin A decreased the symptoms of AD. Thus, these results proved that oroxylin A is an effective component of Scutellaria baicalensis for treating the symptoms of AD.

Astaxanthin Ameliorates Atopic Dermatitis by Inhibiting the Expression of Signal Molecule NF-kB and Inflammatory Genes in Mice

Background: This study was conducted to determine the anti-inflammatory effect of astaxanthin, on atopic dermatitis.Methods: Changes in mouse body weight, lymph node weight, and the degree of improvement in symptoms were measured to determine the inflammatory response. Real-time reverse transcription-polymerase chain reaction tests were performed to determine the degree of expression of inflammation-related cytokines (IL-31 and IL-33 and chemokines such as CCL17 and CCL22), and western blot analysis was performed to evaluate the expression of inflammation-related factors (iNOS, COX-2, and NF-kB signaling molecules p-IkBα, p50, p-65 and pSTAT3).Results: The degree of symptoms significantly improved in the PA+AX group. Lymph node weight in the PA+AX group was lower than the PA group. Inflammatory cytokines (IL-31, IL-33, and inflammatory chemokines such as CCL17 and CCL22) were significantly reduced in the PA+AX group compared with the PA group. The expression of inflammatory genes (iNOS, COX-2, NF-kB and signaling molecules (p-IkBα, p50, p65, and p-STAT 3) was lower in the PA+AX group compared with the PA group.Conclusion: Astaxanthin may modulate the inflammatory response in a mouse model of atopic dermatitis and has an anti-inflammatory effect.

IL-31–generating network in atopic dermatitis comprising macrophages, basophils, thymic stromal lymphopoietin, and periostin

IL-31 is a type 2 cytokine involved in the itch sensation in atopic dermatitis (AD). The cellular origins of IL-31 are generally considered to be TH2 cells. Macrophages have also been implicated as cellular sources of IL-31. We sought to determine the expression of IL-31 by macrophages and to elucidate the productive mechanisms and contributions to itch in AD skin lesions. Expression of IL-31 by macrophages, expressions of thymic stromal lymphopoietin (TSLP) and periostin, and presence of infiltrating basophils in human AD lesions were examined through immunofluorescent staining, and correlations were assessed. Furthermore, mechanisms of inducing IL-31-expressing macrophages were analyzed in an MC903-induced murine model for AD invivo and in mouse peritoneal macrophages exvivo. A significant population of IL-31+ cells in human AD lesions was that of CD68+ cells expressing CD163, an M2 macrophage marker. The number of IL-31+/CD68+ cells correlated with epidermal TSLP, dermal periostin, and the number of dermal-infiltrating basophils. In the MC903-induced murine AD model, significant scratching behaviors with enhanced expressions of TSLP and periostin were observed, accompanied by massive infiltration of basophils and IL-31+/MOMA-2+/Arg-1+ cells. Blockade of IL-31 signaling with anti-IL-31RA antibody or direct depletion of macrophages by clodronate resulted in attenuation of scratching behaviors. To effectively reduce lesional IL-31+ macrophages and itch, basophil depletion was essential in combination with TSLP- and periostin-signal blocking. Murine peritoneal macrophages produced IL-31 when stimulated with TSLP, periostin, and basophils. A network comprising IL-31-expressing macrophages, TSLP, periostin, and basophils plays a significant role in AD itch.

059 IL-31 causes anxiety-like behavior in a mouse model of atopic dermatitis

Atopic dermatitis (AD) is a chronic, recurrent, itchy, inflammatory skin disease. The coexistence of anxiety, depression, and social withdrawal is problematic in AD. Although an association between AD and anxiety and depressive behavior has been observed in humans and in a few mouse models, the detailed mechanisms are unknown. To address this issue, we analyzed the mental state of mice using AD models. We sensitized mice with 3% oxazolone (OXA) and then repeatedly applied 0.6% OXA to the ears of mice 3 times per week for 4 weeks.

331 Mitochondrial stress contributes to atopic dermatitis

Atopic dermatitis (AD) is a complex disease characterized by eczematous lesions over dry skin and local and systemic oxidative stress. Indeed, patients with AD display increased concentrations of oxidative stress biomarkers in the urine, blood, and saliva. Although the source of ROS in AD is uncertain, dysfunctional mitochondria might be involved in excessive oxidative stress in AD skin. In this study, we investigated oxidative stress in AD epidermis by using a mouse model of AD, i.e. flaky tail (ft/ft) mice, and primary keratinocytes and skin biopsies from AD patients.

359 Skin deep and beyond: Function of Calprotectin (S100A8/A9)

Skin diseases affect 900 million people worldwide. Skin colonization by Staphylococcus aureus ( S. aureus) is a hallmark of Atopic Dermatitis (AD), the most common inflammatory skin disease (ISD). The expression of antimicrobial peptides (AMPs) such as S100A8 (A8), S100A9 (A9) and the A8/A9 heterodimer Calprotectin (CP) was reported to be elevated in ISDs, which likely influences S. aureus growth. In the JunBΔep genetic mouse model of AD, constitutive epidermal deletion of JunB leads to skin inflammation with S.

180 The antimicrobial peptide derived from insulin-like growth factor-binding protein 5 promotes skin barrier function and relieves dermatitis-like symptoms in a mouse model of atopic dermatitis

The antimicrobial peptide derived from insulin-like growth factor-binding protein 5 (AMP-IBP5) displays antimicrobialactivities and immunomodulatory properties; however, its role in the regulation of skin barrier in the context of atopic dermatitis (AD) remains unclear. Normal human keratinocytes were stimulated with AMP-IBP5 and Western blot was used to analyze the expression of tight junction (TJ)-related proteins. Immunofluorescence staining was used to examine the intercellular distribution of TJ-related proteins.

Isosorbide Fatty Acid Diesters Have Synergistic Anti-Inflammatory Effects in Cytokine-Induced Tissue Culture Models of Atopic Dermatitis.

Atopic dermatitis (AD) is a chronic disease in which epidermal barrier disruption triggers Th2-mediated eruption of eczematous lesions. Topical emollients are a cornerstone of chronic management. This study evaluated efficacy of two plant-derived oil derivatives, isosorbide di-(linoleate/oleate) (IDL) and isosorbide dicaprylate (IDC), using AD-like tissue culture models. Treatment of reconstituted human epidermis with cytokine cocktail (IL-4 + IL-13 + TNF-α + IL-31) compromised the epidermal barrier, but this was prevented by co-treatment with IDL and IDC. Cytokine stimulation also dysregulated expression of keratinocyte (KC) differentiation genes whereas treatment with IDC or IDL + IDC up-regulated genes associated with early (but not late) KC differentiation. Although neither IDL nor IDC inhibited Th2 cytokine responses, both compounds repressed TNF-α-induced genes and IDL + IDC led to synergistic down-regulation of inflammatory (IL1B, ITGA5) and neurogenic pruritus (TRPA1) mediators. Treatment of cytokine-stimulated skin explants with IDC decreased lactate dehydrogenase (LDH) secretion by more than 50% (more than observed with cyclosporine) and in vitro LDH activity was inhibited by IDL and IDC. These results demonstrate anti-inflammatory mechanisms of isosorbide fatty acid diesters in AD-like skin models. Our findings highlight the multifunctional potential of plant oil derivatives as topical ingredients and support studies of IDL and IDC as therapeutic candidates.

323 A Novel, Stress-Responsive and Clinically Predictive Humanized Mouse Model of Atopic Dermatitis: Autologous Th2-Polarized Lymphocytes Suffice to Induce Characteristic Lesions in Healthy Non-Atopic Human Skin Xenotransplants In Vivo

Clinically relevant in vivo models for atopic dermatitis (AD) are needed, in which the minimal signals required for AD induction in human skin can be defined and candidate therapeutics explored. Here, we report a novel humanized AD mouse model that uses split-thickness skin from healthy, non-atopic female human donors xenotransplanted onto SCID/beige mice and injected with autologous, Th2-polarized PBMCs. After intradermal injection of PBMCs preincubated only with IL-2, IL-4 and LPS, the xenotransplants develop a phenocopy of human AD lesions, including epidermal hyperplasia, hyperproliferation, erythema, and skin barrier impairment (reduced filaggrin and claudin-1 expression, altered corneocyte nanotexture [atomic force miocroscopy]).

400 308-nm excimer lamp ameliorates MC-903 induced atopic dermatitis with a reduction of thymic stromal lymphopoietin mRNA levels

Purpose Narrow band-ultraviolet B (NB-UVB) is efficacious for atopic dermatitis (AD). However, its detailed mechanism remains to be elucidated. The purpose of this study is to explore an in vivo-effect of NB-UVB on AD, utilizing MC903-induced AD model mice. Method To induce AD-like dermatitis, MC903, a vitamin D3 analogue, was applied on the shaved dorsal skin of C57BL/6 mice once a day for twelve days. Mice were irradiated with a 308-nm excimer lamp at 100 mJ/cm2 once every other day from days 0 to 10.

Association between early life antibiotic exposure and development of early childhood atopic dermatitis

Atopic dermatitis (AD) is a chronic, inflammatory skin disease commonly onset during infancy. We examine the association between pre-and postnatal antibiotic exposure and the development of AD. A retrospective, observational study analyzed 4106 infants at the University of Florida from June 2011 to April 2017. Antibiotic exposure during the first year of life was associated with a lower risk of AD. The association was strongest for exposure during the first month of life. There were no significant differences in the rates of AD in infants with or without exposure to antibiotics in months 2 through 12, when examined by month. Antibiotic exposure during week 2 of life was associated with lower risk of AD, with weeks 1, 3, and 4 demonstrating a similar trend. Retrospective data collection from a single center, use of electronic medical record, patient compliance with prescribed medication, and variable follow-up. Early life exposures, such as antibiotics, may lead to long-term changes in immunity. Murine models of atopic dermatitis demonstrate a "critical window" for the development of immune tolerance to cutaneous microbes. Our findings suggest that there may also be a "critical window" for immune tolerance in human infants, influenced by antibiotic exposure.

Genomic control of inflammation in experimental atopic dermatitis

Atopic Dermatitis (AD) or eczema, a recurrent allergic inflammation of the skin, afflicts 10–20% of children and 5% adults of all racial and ethnic groups globally. We report a new topical treatment of AD by a Nuclear Transport Checkpoint Inhibitor (NTCI), which targets two nuclear transport shuttles, importin α5 and importin β1. In the preclinical model of AD, induced by the active vitamin D3 analog MC903 (calcipotriol), NTCI suppressed the expression of keratinocyte-derived cytokine, Thymic Stromal Lymphopoietin (TSLP), the key gene in AD development. Moreover, the genes encoding mediators of TH2 response, IL-4 and its receptor IL-4Rα were also silenced together with the genes encoding cytokines IL-1β, IL-6, IL-13, IL-23α, IL-33, IFN-γ, GM-CSF, VEGF A, the chemokines RANTES and IL-8, and intracellular signal transducers COX-2 and iNOS. Consequently, NTCI suppressed skin infiltration by inflammatory cells (eosinophils, macrophages, and CD4 + T lymphocytes), and reduced MC903-evoked proliferation of Ki-67-positive cells. Thus, we highlight the mechanism of action and the potential utility of topical NTCI for treatment of AD undergoing Phase 1/2 clinical trial (AMTX-100 CF, NCT04313400).

Topical Administration of a Novel Acetylated Tetrapeptide Suppresses Vascular Permeability and Immune Responses and Alleviates Atopic Dermatitis in a Murine Model.

Although the pathogenesis of atopic dermatitis (AD) remains to be fully deciphered, skin barrier abnormality and immune dysregulation are known to be involved. Recently, the vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) system has also been implicated in the pathogenesis of this multifactorial chronic inflammatory skin disorder. Previously, we showed that a novel tetrapeptide, N-acetyl-Arg-Leu-Tyr-Glu (Ac-RLYE), inhibits angiogenesis and vascular permeability effectively by selectively antagonizing VEGFR-2. The current study aimed to investigate the pharmacological effect of Ac-RLYE on AD in vitro and in vivo. The in vitro experiments demonstrated that Ac-RLYE inhibited VEGF-induced vascular permeability in endothelial cells. Moreover, in an in vivo animal model of AD, Ac-RLYE relieved AD-like symptoms such as ear thickness and dermatitis severity scores and infiltration of immune cells, including mast cells and eosinophils. Ac-RLYE inhibited IgE secretion, restored the skin barrier protein filaggrin level, and markedly downregulated gene expression of AD-related Th1, Th2, and Th17 cytokines. Collectively, these findings suggest that Ac-RLYE would be useful for the treatment of AD and associated inflammatory skin disorders.

Effects of Indole-3-Lactic Acid, a Metabolite of Tryptophan, on IL-4 and IL-13-Induced Human Skin-Equivalent Atopic Dermatitis Models.

Indole-3-lactic acid (I3LA) is a well-known metabolite involved in tryptophan metabolism. Indole derivatives are involved in the differentiation of immune cells and the synthesis of cytokines via the aryl hydrocarbon receptors for modulating immunity, and the indole derivatives may be involved in allergic responses. I3LA was selected as a candidate substance for the treatment of atopic dermatitis (AD), and its inhibitory effect on AD progression was investigated. Full-thickness human skin equivalents (HSEs) consisting of human-derived cells were generated on microfluidic chips and stimulated with major AD-inducing factors. The induced AD-HSEs were treated with I3LA for 7 days, and this affected the AD-associated genetic biomarkers and increased the expression of the major constituent proteins of the skin barrier. After the treatment for 14 days, the surface became rough and sloughed off, and there was no significant difference between the increased AD-related mRNA expression and the skin barrier protein expression. Therefore, the short-term use of I3LA for approximately one week is considered to be effective in suppressing AD.

An Inflamed and Infected Reconstructed Human Epidermis to Study Atopic Dermatitis and Skin Care Ingredients.

Atopic dermatitis (AD), the most common inflammatory skin disorder, is a multifactorial disease characterized by a genetic predisposition, epidermal barrier disruption, a strong T helper (Th) type 2 immune reaction to environmental antigens and an altered cutaneous microbiome. Microbial dysbiosis characterized by the prevalence of Staphylococcus aureus (S. aureus) has been shown to exacerbate AD. In recent years, in vitro models of AD have been developed, but none of them reproduce all of the pathophysiological features. To better mimic AD, we developed reconstructed human epidermis (RHE) exposed to a Th2 pro-inflammatory cytokine cocktail and S. aureus. This model well reproduced some of the vicious loops involved in AD, with alterations at the physical, microbial and immune levels. Our results strongly suggest that S. aureus acquired a higher virulence potential when the epidermis was challenged with inflammatory cytokines, thus later contributing to the chronic inflammatory status. Furthermore, a topical application of a Castanea sativa extract was shown to prevent the apparition of the AD-like phenotype. It increased filaggrin, claudin-1 and loricrin expressions and controlled S. aureus by impairing its biofilm formation, enzymatic activities and inflammatory potential.

Cellular Anti-Inflammatory and Antioxidant Activities of Bamboo Sasa albomarginata Leaf Extract and Its Constituent Coumaric Acid Methyl Ester.

Hot water extract of Sasa albomarginata (Kumazasa) leaves is commercially available and used as a dietary supplement or skincare cream. The extract possesses anti-inflammatory activity on the mouse atopic dermatitis model. To elucidate the mechanism of in vivo activity, we have studied the cellular anti-inflammatory and antioxidant activities of the extract and its constituents. Secretion of mouse and human IL-6 was measured by ELISA. ROS production was measured by a fluorescent reagent. Ultrahigh performance liquid chromatography (UHPLC)/MS was used for the ingredient analysis. The Sasa albomarginata extract inhibited inflammatory mediators such as LPS-induced NO, IL-6, and ROS production in mouse monocyte leukemia RAW264.7 cells. It also inhibited iNOS, IL-6, and IL-1β expressions. Moreover, it inhibited LPS-induced IL-6 expression and production in human monocyte leukemia THP-1 cells differentiated into macrophages. The HPLC analysis of the extract revealed the existence of coumaric acid, ferulic acid, and coumaric acid methyl ester. Coumaric acid methyl ester but not coumaric acid or ferulic acid inhibited LPS-induced NO, IL-6, and ROS production in RAW264.7 cells and IL-6 production in differentiated THP-1 cells. The hot water extract of Sasa albomarginata leaves and one of its constituents possess cellular anti-inflammatory and antioxidant activities.