Atopic Dermatitis-like Model Research Articles

Schizonepeta tenuifolia Briq-Saposhnikovia divaricata decoction alleviates atopic dermatitis via downregulating macrophage TRPV1.

Schizonepeta tenuifolia -Saposhnikovia divaricata (Jingjie-Fangfeng, JF) has been used for years to treat allergic inflammatory skin diseases like atopic dermatitis, but the specific effects and mechanisms of JF are still unclear. We aim to investigate the therapeutic effect and mechanism of JF in MC903-induced atopic dermatitis-like model. JF decoction was subjected to rigorous HPLC and GC analysis. The JF decoction was then freshly prepared and administered to MC903-induced atopic dermatitis -like mice models to investigate its therapeutic effects. Our evaluation focused on several markers of inflammation including the TEWL index, ear thickness, swelling, and specific inflammation indicators such as TSLP, IL33, IgE, and immune cell presence at the lesion sites. We measured Transient Receptor Potential Vanilloid 1 (TRPV1) expression levels through immunofluorescent staining in skin tissue from both atopic dermatitis patients and the MC903-treated mice. Furthermore, TRPV1 expression and macrophage activation markers were measured in LPS/IFN-γ-stimulated Raw264.7 and THP-1 cell models in vitro. Additionally, we developed cell lines that overexpress TRPV1 and investigated how JF treatment affects NF-κB p65 phosphorylation in these cells to understand better the role of TRPV1 in atopic dermatitis. The JF decoction met the standards outlined in the Chinese pharmacopeia. The JF decoction significantly alleviated inflammatory skin symptoms and helped restore skin barrier function. Additionally, it reduced the levels of IgE and pro-inflammatory cytokines TSLP, IL-33, and IL-4. There was also a noticeable decrease in mast cell infiltration and degranulation. Notably, JF decoction reduced infiltrated macrophages with limited affection on T cell infiltration. It also decreased F4/80+/TRPV1+ cells in atopic dermatitis mice and TRPV1 expression in LPS/IFNγ-stimulated microphages. Additionally, we observed that CD68+/TRPV1+ cells increased in human atopic dermatitis tissue. Further studies showed that JF water extract (JF-WE) suppressed TRPV1 expression in macrophages, potentially by affecting NF-κB p65 phosphorylation rather than the JAK-STAT6 pathway. This study offers initial evidence of the effectiveness of JF-WE in suppressing inflammation in atopic dermatitis. The therapeutic effect might stems from its ability to downregulate TRPV1 expression and subsequent NF-κB p65 phosphorylation in macrophages.

Evodiamine Alleviates 2,4-Dinitro-1-Chloro-Benzene-Induced Atopic Dermatitis-like Symptoms in BALB/c Mice.

Evodiamine is an alkaloid found in Evodia fruits, a traditional Chinese medicine. Preclinical studies have demonstrated its anti-inflammatory and neuroprotective properties. The 2,4-dinitro-1-chloro-benzene (DNCB) was used to test the effects of evodiamine on a chemically induced atopic dermatitis-like model in BALB/c mice. Evodiamine significantly lowered serum immunoglobulin E levels, which increased as an immune response to the long-term application of DNCB. Several atopic dermatitis-like skin symptoms induced by DNCB, including skin thickening and mast cell accumulation, were suppressed by evodiamine therapy. DNCB induced higher levels of pro-inflammatory cytokines in type 2 helper T (Th2) cells (IL-4 and IL-13), Th1 cells (IFN-γ and IL-12A), Th17 cells (IL-17A), Th22 cells (IL-22), and chemokines (IL-6 and IL-8). These increases were suppressed in the lymph nodes and skin following evodiamine treatment. The results of our study indicate that evodiamine suppresses atopic dermatitis-like responses in mice and may therefore be useful in treating these conditions.

Gasdermin A Is Required for Epidermal Cornification during Skin Barrier Regeneration and in an Atopic Dermatitis-Like Model

Atopic dermatitis (AD) is featured with impaired skin barrier. The stratum corneum (SC) and the intercellular tight junctions (TJs) constitute the permeability barrier, which is essential to protect the host water loss and pathogen entrance. The epidermal barrier is constantly renewed by differentiating keratinocytes through cornification, during which autophagy contributes to organelles and nucleus elimination. The human GSDMA and its mouse homologs Gsdma1-3 are expressed in the suprabasal epidermis. Although a pyroptotic role for GSDMA/Gsdma1 in host defense against Streptococcus pyogenes has been reported, the physiological function of Gsdma1/a2/a3 in epidermal homeostasis remains elusive. Herein, through repeated epidermal barrier disruption, we found that TJ formation and SC maturation were defective in the Gsdma1/a3-deficient epidermis. Using comparative gene profiling analysis, mitochondrial respiration measurement, and in vivo tracing of mitophagy, our data indicate that Gsdma1/a3 activation leads to mitochondrial dysfunction and subsequently facilitates mitochondrial turnover and epidermal cornification. In calcipotriol (MC903)-induced AD-like animal model, we demonstrated that Gsdma1/a3-deficiency selectively enhanced the Th2 response. Remarkably, the GSDMA expression is reduced in the epidermis of patients with AD compared to normal individuals. Gsdma1/a3-deficiency might be involved in AD pathogenesis, likely through GSDMA-mediated epidermal differentiation and cornification.

Modulation of Skin Inflammatory Responses by Aluminum Adjuvant

Aluminum salt (AS), one of the most commonly used vaccine adjuvants, has immuno-modulatory activity, but how the administration of AS alone may impact the activation of the skin immune system under inflammatory conditions has not been investigated. Here, we studied the therapeutic effect of AS injection on two distinct skin inflammatory mouse models: an imiquimod (IMQ)-induced psoriasis-like model and an MC903 (calcipotriol)-induced atopic dermatitis-like model. We found that injection of a high dose of AS not only suppressed the IMQ-mediated development of T-helper 1 (Th1) and T-helper 17 (Th17) immune responses but also inhibited the IMQ-mediated recruitment and/or activation of neutrophils and macrophages. In contrast, AS injection enhanced MC903-mediated development of the T-helper 2 (Th2) immune response and neutrophil recruitment. Using an in vitro approach, we found that AS treatment inhibited Th1 but promoted Th2 polarization of primary lymphocytes, and inhibited activation of peritoneal macrophages but not bone marrow derived neutrophils. Together, our results suggest that the injection of a high dose of AS may inhibit Th1 and Th17 immune response-driven skin inflammation but promote type 2 immune response-driven skin inflammation. These results may provide a better understanding of how vaccination with an aluminum adjuvant alters the skin immune response to external insults.

The Preventive Effect of Topical Administration of Human Mesenchymal Stem Cells-Conditioned Medium (MSC-CM) on DNCB-Induced Atopic Dermatitis-Like Model in Mice

The Preventive Effect of Topical Administration of Human Mesenchymal Stem Cells-Conditioned Medium (MSC-CM) on DNCB-Induced Atopic Dermatitis-Like Model in Mice

Intervention of the Mahuang Lianqiao Chixiaodou decoction on immune imbalance in atopic dermatitis-like model mice

To explore the potential mechanism of intervention on the immune imbalance of atopic dermatitis (AD) by studying the effects of Mahuang Lianqiao Chixiaodou decoction (MLCD) on skin damage and inflammation factors in an AD-like mouse model. Ninety-six male BALB/c mice were divided into normal, model, positive control (mometasone furoate), and traditional Chinese medicine treatment (MLCD) groups by a random number table. 2,4-dinitrofluorobenzene was used to induce AD-like mice in all groups except the normal group. The treatment or intervention was administered for seven consecutive days on days 4, 18, 32, and 39. The mRNA relative expressions of interleukin-4 (IL-4), IL-10, interferon-γ (IFN-γ), thymic stromal lymphopoietin (TSLP), and the TSLP receptor (TSLPR) were measured using quantitative real-time polymerase chain reaction, and the serum immunoglobulin E, IL-4, IL-10, and IFN-γ levels were detected using enzyme-linked immunosorbent assay. Compared with the normal group, the hematoxylin-eosin staining of the skin lesions of the mice in the model group was significantly thickened on days 11, 25, and 39. Compared with the model group, the epidermal thickness of the positive control group was significantly alleviated on day 39 ( P < .001), and that of the MLCD group was significantly improved on days 25 and 39 ( P < .001). Compared with the four observation time points, MLCD had the best treatment effect on day 39 of the experiment and significantly improved the skin damage performance and relieved pathological lesions. On day 39, compared with the model group, MLCD downregulated the skin mRNA relative expressions of IL-4 ( P = .009), TSLP ( P = .030), and TSLPR ( P < .001), and reduced the mouse serum levels of IL-4 ( P = .003). For other serum indicators, no significant difference was observed between the model and MLCD groups. MLCD improved AD-like mice skin damage by regulating the Th1/Th2 immune imbalance.

Therapeutic effects of soluble human leukocyte antigen G2 isoform in lupus-prone MRL/lpr mice

Human leukocyte antigen (HLA)-G, a non-classical HLA class I molecule, has one of the splicing isoforms, HLA-G2, which lacks one domain (α2) and forms a non-covalent homodimer. HLA-G2 is expressed on placental cells, regulatory T cells, tumor cells, and virus-infected cells, and is involved in immunosuppression. The major isoform of HLA-G, HLA-G1, binds to leukocyte immunoglobulin (Ig)-like receptor (LILR) B1 and LILRB2, on the contrary, HLA-G2 binds to only LILRB2. We previously reported that HLA-G2 bound LILRB2 more strongly than HLA-G1 and also to paired Ig-like receptor (PIR)-B, a mouse homolog of LILRBs. Furthermore, HLA-G2 showed immunosuppressive effects in both collagen-induced arthritis (CIA) and atopic dermatitis-like model mice. In this study, we examine in vivo effects of HLA-G2 in systemic lupus erythematosus (SLE) model mice. HLA-G2 showed the suppression of the typical SLE symptoms such as serum anti-dsDNA antibody level and urinary albumin index. Furthermore, HLA-G2 tended to downregulate B-lymphocyte stimulator (BLyS) production. This is the first observation of the immunosuppressive effects of HLA-G2 isoform in SLE model mice, suggesting that HLA-G2 could be a useful therapeutic agent for SLE.

125 Characterization of TSG-6 protein in healthy and inflammatory models of reconstructed human epidermis

TSG-6 is an anti-inflammatory hyaluronan-binding protein involved in extracellular matrix remodelling whose functions have never been studied in skin. Characterization of TSG-6 was carried out in vivo in healthy human epidermis and in vitro using keratinocyte monolayers and reconstructed human epidermis (RHE). Distribution of TSG-6 protein was highlighted by immunofluorescence and levels of relative mRNA and protein expression were respectively measured by RT-qPCR and ELISA. The immunofluorescent signal of TSG-6 protein was located in the living layers of epidermis in vivo and in vitro, mostly in basal keratinocytes, and was restricted to the intracellular compartment. Because the localization of hyaluronan (HA) is in the extracellular matrix, no colocalization of TSG-6 and HA could thus be detected. ELISA assay shows that TSG-6 is abundant in the intracellular compartment, and is present in weak amounts in pericellular spaces, as well as in the culture medium. In vitro, TSG-6 mRNA level did not change during epidermal differentiation induced by confluence and increased cell density. The expression of TSG-6 was then analysed in RHE subjected to inflammatory conditions using two different models. In the first one, RHE were infected with arthrospores of Trichophyton rubrum dermatophyte, allowing adhesion and invasion of cornified layer by fungal elements. The second one corresponds to an atopic dermatitis-like model where RHE were first deprived from plasma membrane cholesterol using methyl-b-cyclodextrin ahead of exposure to interleukins (IL-4, IL-13, IL-25). In both inflammatory models, despite TSG-6 mRNA and protein levels were increased, simultaneously with an increase in HA fluorescent detection no colocalization of TSG-6 with HA was ever detected. In summary, these results demonstrate that TSG-6 is present intracellularly in epidermal keratinocytes in physiological conditions, and its expression is induced by inflammatory conditions. Only low concentration of this protein is detectable extracellularly.

Effect of Dangguibohyul-Tang, a Mixed Extract of Astragalus membranaceus and Angelica sinensis, on Allergic and Inflammatory Skin Reaction Compared with Single Extracts of Astragalus membranaceus or Angelica sinensis

Dangguibohyul-tang (DBT), herbal formula composed of Astragalus membranaceus (AM) and Angelica sinensis (AS) at a ratio of 5 : 1, has been used for the treatment of various skin diseases in traditional medicine. We investigated the effect of DBT on allergic and inflammatory skin reaction in atopic dermatitis-like model compared to the single extract of AM or AS. DBT treatment showed the remission of clinical symptoms, including decreased skin thickness and scratching behavior, the total serum IgE level, and the number of mast cells compared to DNCB group as well as the single extract of AM- or AS-treated group. Levels of cytokines (IL-4, IL-6, IFN-γ, TNF-α, and IL-1β) and inflammatory mediators (NF-κB, phospho-IκBα, and phospho-MAPKs) were significantly decreased in AM, AS, and DBT groups. These results demonstrated that AM, AS, and DBT may have the therapeutic property on atopic dermatitis by inhibition of allergic and inflammatory mediators and DBT formula; a mixed extract of AM and AS based on the herb pairs theory especially might be more effective on antiallergic reaction as compared with the single extract of AM or AS.

Hizikia fusiformis fractions successfully improve atopic dermatitis indices in anti-CD3-stimulated splenocytes and 2,4-dinitrochlorobenzene-treated BALB/c mice

In the present study, we aimed to examine whether fractions from an edible sea weed, Hizikia fusiformis, had immunomodulatory effects, particularly an anti-atopic effect, by attenuating the expression of T cell-dependent cytokines using in-vitro and in-vivo animal atopic dermatitis-like models. The anti-atopic activities were examined in in vitro, and a 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis-like mouse model using quantitative real-time polymerase chain reaction, electrophoretic-mobility shift and histopathological analysis. Our results showed that the final fraction (F2') of H. fusiformis contained a higher amount of butanoic acid which was not found in the other fractions, and effectively inhibited T cell activation by inhibiting dephosphorylation of nuclear factor of activated T cells in electrophoretic-mobility shift assay. As a consequence, helper T cell-dependent cytokines, such as interleukin-2, -4 and interferon-γ, were significantly inhibited while activated with an anti-CD3 antibody. We also showed that skin challenged with DNCB successfully recovered when treated with 2.5 mg/kg, comparable to that by 0.25% prednicarbate. These results indicate that F2' may contribute to inhibit T cell activation by eliminating Th cell-dependent cytokines. Taken together, we concluded that F2' containing butanoic acid may be a new functional anti-atopic candidate, which probably acts through nuclear factor of activated T cell inactivation mechanisms.

황련해독탕(黃連解毒湯)의 아토피 피부염 개선 효과(效果)

Objectives : The water extract of Hwangnyeonhaedok-tang (HHT), composed of the Scutellariae Radix, Coptidis Rhizoma, Phellodendri Cortex and Gardeniae Fructus has been traditionally used to treat fever, inflammation, gastritis and hypertension in east asia. However, little is known about the ameliorative effects of HHT on atopic dermatitis. Therefore, the purpose of this study was to investigate the therapeutic effect of HHT on atopic dermatitis Methods : We investigated the inhibitory effects of HHT on the production of proinflammatory cytokines in rat peritoneal mast cells (RPMCs), on the scratching behavior in ICR mice, and on atopic dermatitis symptoms in 2,4-dinitrofluorobenzene (DNFB)-induced atopic dermatitis-like model hairless mice. Results : Levels of TNF- and IL- increased by PMA plus A23187 co-treatment were significantly inhibited by HHT in a dose-dependent manner. HHT also inhibited the histamine release from RPMCs stimulated by compound 48/80, which promotes histamine release. The oral administration of HHT reduced the scratching behavior induced by compound 48/80 and histamine in ICR mice. Furthermore, the intradermal treatment of HHT reduced the ear edema, skin lesions, and atopic molecular marker (IgE and IL-4) in DNFB-induced atopic dermatitis model mice. Conclusions : These results suggest that HHT may be used as a potential treatment for AD as a prescription for treatment of atopic dermatitis.

Noninvasive delivery of siRNA into the epidermis by iontophoresis using an atopic dermatitis-like model rat

Topical application of siRNA to the skin should be an effective treatment for serious skin disorders, such as atopic dermatitis. However, it is difficult to introduce hydrophilic macromolecules, including siRNA, into the skin by conventional methods. For efficient delivery of siRNA, we examined an iontophoretic technique, since it is suitable for the delivery of charged molecules. Naked siRNA effectively accumulated in the epidermis (and not in the dermis) after iontophoretic delivery. In contrast, siRNA did not penetrate tape-stripped skin by passive diffusion. In a rat model of atopic dermatitis, skin was sensitized with ovalbumin to stimulate IL-10 mRNA expression as observed in skin lesions. Iontophoretic delivery of anti-IL-10 siRNA significantly reduced (73%) the level of IL-10 mRNA. In conclusion, we successfully delivered naked siRNA into the epidermis and concomitantly suppressed the expression of an endogenous immuno-regulatory cytokine.