Therapeutic Perspectives in Atopic Dermatitis

Hydrogels Treat Atopic Dermatitis by Transporting Marine-Derived miR-100-5p-Abundant Extracellular Vesicles

Atopic dermatitis (AD) is a prevalent skin disorder worldwide. However, many AD medications are unsuitable for long-term use due to low therapeutic efficacy and side effects. Extracellular vesicles (EVs) extracted from Pinctada martensii mucus have demonstrated therapeutic efficacy in AD. It is hypothesized that EVs may exert their activity on mammalian cells through their specific contents. In this study, we analyzed the results of miRNA sequencing of the EVs and investigated the potency of highly expressed miR-100-5p in treating AD. To enhance the therapeutic efficiency of the EVs in AD, we developed oxidized sodium alginate (OSA)-carboxymethyl chitosan (CMCS) self-cross-linked hydrogels as a vehicle to deliver the EVs to BALB/c mice with dermatitis. The miR-100-5p in EVs exhibited a favorable anti-inflammatory function, while the hydrogels provided enhanced skin residency. Additionally, its efficacy in inflammation inhibition and collagen synthesis was demonstrated in in vivo experiments. Mechanistically, miR-100-5p in EVs exerted anti-inflammatory effects by inhibiting the expression of FOXO3, consequently suppressing the activation of the downstream NLRP3 signaling pathway. This study underscores the significance of utilizing OSA-CMCS hydrogels as a vehicle for delivering miR-100-5p in P. martensii mucus-derived EVs for the treatment of AD.

Myricetin treatment has ameliorative effects in DNFB-induced atopic dermatitis mice under high-fat conditions

Atopic dermatitis (AD) is a chronic, inflammatory cutaneous disorder. Obesity is associated with increased prevalence and severity of AD for reasons that remain poorly understood. Myricetin, a dietary flavonoid found in fruits and vegetables, is known to have anti-inflammatory effects, but its role in AD is unclear. Thus, we investigated the effects of obesity on exacerbation AD lesions and evaluated the effects of myricetin on obese AD. Mice were fed normal diet (ND) or high-fat diet, and then 2,4-dinitrofluorobenzene was used to induce AD-like lesions. We found that obesity exacerbated AD lesions, and myricetin topical administration ameliorated symptoms and skin lesions of obsess AD mice, such as dermatitis scores, scratching behavior, epidermal thickness, and mast cell infiltration. In addition, myricetin reduced the levels of immunoglobulin E and histamine, inhibited the infiltration of CD4+T cells, and modulated the expression of Th1, Th2, Th17, and Th22 cytokines and pro-inflammatory factors (CCL17, CCL22, IL-1β, and TGF-β). Moreover, myricetin restored impaired barrier function by reducing transepidermal water loss, increasing lamellar body secretion, as well as upregulating the mRNA and protein expression of filaggrin. Western blot results showed that significantly increased levels of phosphorylated IκB and NF-κB p65 was observed in the obese AD mice compared with the AD mice fed ND, whereas the myricetin could downregulated the phosphorylations of IκB and NF-κB, and inhibited mRNA expression of iNOS and COX2. Taken together, our results suggest that myricetin treatment exhibits potentially protective effects against the obeseassociated AD by inhibiting inflammatory response and restoring skin barrier function.

Impressic Acid Ameliorates Atopic Dermatitis-Like Skin Lesions by Inhibiting ERK1/2-Mediated Phosphorylation of NF-κB and STAT1

Impressic acid (IPA), a lupane-type triterpenoid from Acanthopanax koreanum, has many pharmacological activities, including the attenuation of vascular endothelium dysfunction, cartilage destruction, and inflammatory diseases, but its influence on atopic dermatitis (AD)-like skin lesions is unknown. Therefore, we investigated the suppressive effect of IPA on 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin symptoms in mice and the underlying mechanisms in cells. IPA attenuated the DNCB-induced increase in the serum concentrations of IgE and thymic stromal lymphopoietin (TSLP), and in the mRNA levels of thymus and activation regulated chemokine (TARC), macrophage derived chemokine (MDC), interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13 (IL-13), tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) in mice. Histopathological analysis showed that IPA reduced the epidermal/dermal thickness and inflammatory and mast cell infiltration of ear tissue. In addition, IPA attenuated the phosphorylation of NF-κB and IκBα, and the degradation of IκBα in ear lesions. Furthermore, IPA treatment suppressed TNF-α/IFN-γ-induced TARC expression by inhibiting the NF-κB activation in cells. Phosphorylation of extracellular signal-regulated protein kinase (ERK1/2) and the signal transducer and activator of transcription 1 (STAT1), the upstream signaling proteins, was reduced by IPA treatment in HaCaT cells. In conclusion, IPA ameliorated AD-like skin symptoms by regulating cytokine and chemokine production and so has therapeutic potential for AD-like skin lesions.

Non-thermal plasma inhibits mast cell activation and ameliorates allergic skin inflammatory diseases in NC/Nga mice

Non-thermal plasma (NTP) has many functional activities such as, sterilization, wound healing and anti-cancer activity. Despite of its wide spread biomedical application, the effect of NTP on immune cells and allergic response has not been well studied. In this study, we determined whether NTP suppresses mast cell activation, which is important for allergic response, and ameliorates an atopic dermatitis (AD)-like skin inflammatory disease in mice. Exposure to NTP-treated medium during mast cell activation inhibited the expression and production of IL-6, TNF-α and suppressed NF-κB activation. We also investigated whether NTP treatment ameliorates house dust mite (HDM)-induced AD-like skin inflammation in mice. NTP treatment inhibited increases in epidermal thickness and recruitment of mast cells and eosinophils, which are important cell types in AD pathogenesis. In addition, Th2 cell differentiation was induced by application of HDM and the differentiation was also inhibited in the draining lymph node of NTP-treated mice. Finally, the expression of AD-related cytokines and chemokines was also decreased in NTP-treated mice. Taken together, these results suggest that NTP might be useful in the treatment of allergic skin diseases, such as AD.

Cyanidin 3-Rutinoside, an Anthocyanin Pigment of Schisandra chinensis Baill, Inhibits Allergic Inflammation

The occurrence of allergy-mediated inflammatory diseases such as asthma and atopic dermatitis have increased, but comprehensive treatment remains difficult. Previous studies have shown that Schisandra chinensis Baill has antioxidant, antidiabetic, and antitumorigenic effects. Cyanidin 3-rutinoside (CR) is the major anthocyanin pigment of S. chinensis. However, the biological effects of CR have been rarely studied to date. Therefore, the aim of this study was to investigate the regulatory effects of CR on phorbol-12-myristate-13-acetate (PMA)/A23187-induced allergic inflammation in vitro. CR inhibited the secretion of inflammatory cytokines such as interleukin-6 and tumor necrosis factor-α, and it also suppressed the phosphorylation of nuclear factor-kappa B. These results show that CR ameliorated PMA/A23187-induced allergic inflammation via the suppression of inflammatory cytokines in HMC-1 cells. Therefore, CR has potential as a therapeutic agent for allergic diseases.

Umbilical cord-derived mesenchymal stem cell extracts ameliorate atopic dermatitis in mice by reducing the T cell responses

Mesenchymal stem cells derived from Wharton’s jelly of the umbilical cord (UC-MSCs) have immunomodulatory properties. The aim of this study was to explore whether extracts of MSCs (MSC-Ex) could augment the low therapeutic efficacy of the whole cells in an Aspergillus fumigatus (Af)-induced atopic dermatitis (AD) model. LPS- or TNF-α/IFN-γ-stimulated keratinocytes (HaCaT cells) were treated with MSC-Ex, and the Af-induced AD model was established in BALB/c mice. In HaCaT cells, MSC-Ex treatment significantly reduced the inflammatory cytokine (IL-6, IL-1β, IL-4, IL-5 and TNF-α), iNOS and NF-κB levels, and upregulated the anti-inflammatory cytokines (IL-10 and TGF-β1). In the AD mice, the MSC-Ex group showed greatly reduced dermatitis, and lower clinical symptom scores and IgE levels. The histological dermatitis scores were also markedly lower in the MSC-Ex-treated animals compared with the MSC-treated group. Decreased levels of IFN-γ (Th1) and IL-17 (Th17), IL-4 and IL-13 (Th2) were detected in T cells and the skin tissue from the MSC-Ex treated AD mice. The therapeutic capacity of MSC-Ex was preserved after lyophilization and reconstitution. MSC-Ex treatment reproducibly suppresses dermatitis and inhibits the induction of inflammatory cytokines in the skin of AD mice. MSC-Ex is therefore a potential new treatment agent for AD.

Therapeutic effects of bee venom and its major component, melittin, on atopic dermatitis in vivo and in vitro

BACKGROUND AND PURPOSE

Atopic dermatitis (AD) is a multifactorial skin condition with complex interactions of innate and adaptive immune responses. There are several existing therapies for AD, including topical glucocorticosteroids, emollients, phototherapies, calcineurin inhibitors and immunosuppressants, such as cyclosporine A. Although these therapies reduce inflammation, they also cause serious side effects. Therefore, it is necessary to develop new therapeutic approaches for AD treatment without side effects. There are several studies on natural materials or toxins, such as herbs, ginseng extract and snake venom, for AD treatment. However, treatment of AD with bee venom and its major component, melittin has rarely been studied.

EXPERIMENTAL APPROACH

Effects of bee venom and melittin were studied in a model of AD in vivo induced by 1-chloro-2,4-dinitrobenzene (DNCB) in female Balb/c mice and in cultures of human keratinocytes, stimulated by TNF-α/IFN-γ. The potential pharmacological effects of bee venom and melittin on these in vivo and in vitro AD-like skin disease models were studied.

KEY RESULTS

Bee venom and melittin exhibited potent anti-atopic activities, shown by decreased AD-like skin lesions, induced by DNCB in mice. In vitro studies using TNF-α/IFN-γ-stimulated human keratinocytes showed that bee venom and melittin inhibited the increased expression of chemokines, such as CCL17 and CCL22, and pro-inflammatory cytokines, including IL-1β, IL-6 and IFN-γ, through the blockade of the NF-κB and STAT signalling pathways.

CONCLUSIONS AND IMPLICATIONS

Our results suggest that bee venom and melittin would be suitable for epicutaneous application, as topical administration is often appropriate for the treatment of AD.

Oral Aspects Identified in Atopic Dermatitis Patients: A Literature Review

Introduction:

Atopic dermatitis is a chronic inflammatory skin condition that is more prevalent in children (10-20% of the world's population) than in adults. As its etiology is multifactorial, it is important to know the most frequent oral manifestations in atopic dermatitis patients.

Methodology:

In the last decades, the correlation between atopic dermatitis and conditions and/or changes in the oral cavity has been demonstrated by several studies. The objective of this paper was to describe, through a review of the literature, the oral health conditions and/or oral aspects identified in patients with atopic dermatitis.

Search Strategy:

A descriptive literature review was carried out through a bibliographical survey based on the last 10 years, in order to answer the study questions.

Results:

As a result, we found six studies with different sample sizes, ranging from 43 to 468 patients, and the majority of them were of cross-sectional study design.

Discussion:

Two studies performed their analysis through dental exams and reported that patients with atopic dermatitis tend to have a greater frequency of carious lesions, and two studies correlated Candida with atopic dermatitis through mycological analyzes.

Conclusion:

There are a few studies in the literature that identify the oral aspects of atopic dermatitis. More investigations are needed in order to contribute to the knowledge of such oral aspects and the approach to treat these patients regarding oral health.

Ameliorative effects of Juniperus rigida fruit on oxazolone- and 2,4-dinitrochlorobenzene-induced atopic dermatitis in mice

ETHNOPHARMACOLOGICAL RELEVANCE

The fruits of Juniperus rigida have been used in Korean traditional medicine for the treatment of inflammatory diseases in humans such as rheumatoid arthritis.

AIM OF THE STUDY

This study aimed to investigate the anti-atopic properties of J. rigida fruit in in vivo murine atopic dermatitis (AD) models.

METHODS AND RESULTS

BALB/c mouse ears ad SKH-1 hairless mice stimulated with oxazolone (4 weeks) and DNCB (3 weeks), respectively, were treated with the 1% Juniperus rigida fruit EtOH extract (JFE). The JFE improved AD symptoms in both oxazolone- and DNCB-induced AD mice by accelerating skin barrier recovery function and suppressing the overproduction of serum immunoglobulin E (IgE) and interleukin 4 (IL-4). The JFE was found to contain isoscutellarein-7-O-β-xylopyranoside, cupressuflavone, podocarpusflavone A, and hinokiflavone as major components based on phytochemical analysis. Eight flavonoids were isolated from JFE, and of those, cupressuflavone and isoscutellarein-7-O-β-xylopyranoside strongly down-regulated IL-4 expression and β-hexosaminidase release in RBL-2H3 cells.

CONCLUSION

Therapeutic attempts with J. rigida fruit and its active components might be useful in treating AD and related skin inflammatory diseases.

Beneficial effects of melittin on ovalbumin-induced atopic dermatitis in mouse

Atopic dermatitis (AD) is an inflammatory skin disease characterized by intense pruritus and relapsable eczematous lesions. The hallmarks of AD are defects in the epidermal barrier and immunoglobulin E (IgE)-mediated sensitization to several environmental allergens, as well as an immune disorder mediated by an imbalance toward T-helper-2 response. Melittin, a major component of bee venom, has been studied in various inflammatory diseases. However, the beneficial effects of melittin on mouse with AD-like symptoms have not been explored. Therefore, we investigated the anti-allergic effects of melittin. AD was induced by ovalbumin (OVA) patch. After agent treatment, skin tissues and sera were extracted from the sacrificed mice were used to demonstrate the effects of melittin through various molecular biological methods. The results showed that OVA-induced skin thickening and inflammatory infiltration were decreased in the melittin-treated group. Melittin prevented OVA-induced filaggrin deficiency and imbalanced inflammatory mediators. Furthermore, melittin inhibited IL-4/IL-13-induced filaggrin downregulation through the blockade of STAT3 activation in human keratinocytes. In summary, this study has shown that melittin ameliorated OVA-induced AD-like symptoms from various perspectives. The findings of this study may be the first evidence of the anti-inflammatory effects of melittin on OVA-induced AD.

Probiotics in dermatologic practice

OBJECTIVE

Probiotics are live microorganisms that beneficially affect the host when administered in adequate amounts. They have an excellent safety profile. Probiotics have been used as immunomodulators in inflammatory skin conditions, such as atopic dermatitis. The aim of this study was to summarize the available evidence concerning the use of different strains of probiotics in dermatology practice.

METHODS

We conducted a literature review of English and Spanish publications listed in standard databases (PubMed, Ovid, Google Scholar, Medline, and EBSCO), between 1994 and 2015 using the words "probiotics" and "dermatology." We found ∼70 studies containing these criteria and selected 42 in which probiotics were used for dermatologic purposes.

RESULTS

We found enough evidence to recommend the use of probiotics in specific conditions in dermatology practice, especially in children with atopic dermatitis.

CONCLUSIONS

Further well-designed, large population based trials are needed to validate the use of probiotics in dermatology practice, including innovative therapies to rebuild skin barrier defects, protection against microbial colonization, and restoration of immunologic balance.

Interferons: Success in anti-viral immunotherapy

The interferons (IFNs) are glycoproteins with strong antiviral activities that represent one of the first lines of host defense against invading pathogens. These proteins are classified into three groups, Type I, II and III IFNs, based on the structure of their receptors on the cell surface. Due to their ability to modulate immune responses, they have become attractive therapeutic options to control chronic virus infections. In combination with other drugs, Type I IFNs are considered as "standard of care" in suppressing Hepatitis C (HCV) and Hepatitis B (HBV) infections, while Type III IFN has generated encouraging results as a treatment for HCV infection in phase III clinical trials. However, though effective, using IFNs as a treatment is not without the need for caution. IFNs are such powerful cytokines that affect a wide array of cell types; as a result, patients usually experience unpleasant symptoms, with a percentage of patients suffering system wide effects. Thus, constant monitoring is required for patients treated with IFN in order to reach the treatment goals of suppressing virus infection and maintaining quality of life.

Bone marrow-derived clonal mesenchymal stem cells inhibit ovalbumin-induced atopic dermatitis

Mesenchymal stem cells (MSCs) possess immunomodulatory activities, including suppression of T- and B-cell activation. However, their effects on atopic dermatitis (AD) have not yet been studied. Using an ovalbumin-induced AD mouse model, we investigated whether MSCs can be used as therapeutics in AD. We isolated both allogeneic and syngeneic clonal MSCs (cMSCs) from mouse bone marrow according to the subfractionation culturing method. Our cMSCs suppressed both T- and B-cell activation. T-cell proliferation and cytokine production, including interferon (IFN)-γ and interleukin (IL)-4, were suppressed by inhibition of transcription factors, such as T-bet, GATA-3, and c-Maf. Those transcription factors were nitric oxide dependent. Immunoglobulin E (IgE) suppression occurred through downregulation of AID and BLIMP-1, important regulators for isotype class switch and B-cell differentiation. The cMSCs were injected intravenously into ovalbumin-induced AD mouse model, and the therapeutic effects were analyzed. Injection of both allogeneic and syngeneic cMSCs in an AD mouse model inhibited cell infiltration in skin lesions and decreased the serum level of IgE. IL-4 expression was also suppressed by cMSCs in both the lymph node and skin. The cMSCs migrated to skin lesions and draining lymph nodes. Taken together, these data demonstrated that cMSCs, which suppressed T- and B-cell functions, can be used for the treatment of AD in mice.

Pathogenic intracellular and autoimmune mechanisms in urticaria and angioedema

Urticaria and angioedema are common disorders. Chronic urticaria is defined as lasting longer than 6 weeks. Causes of chronic urticaria fall into the following categories: physical, allergic, hereditary, autoimmune, and idiopathic. Basophils and mast cells are the primary effector cells responsible for clinical symptoms and signs. These cells produce and secrete a variety of mediators including histamine, leukotrienes, prostaglandins, cytokines, chemokines, and other pro-inflammatory mediators. This leads to vasodilation, fluid exudation, increased vascular permeability, and accumulation of additional secondary inflammatory cells. Two mechanisms have been investigated as possibly contributing to the pathogenesis of chronic urticaria. One is the development of autoantibodies to FcεRI or IgE on mast cells and basophils. This appears to be responsible for 30-50 % of cases. The other is dysregulation of intracellular signaling pathways involving Syk, SHIP-1, or SHIP-2 in basophils and mast cells. The primary treatment for chronic urticaria is to treat the underlying pathology, if any can be identified. Otherwise, in idiopathic cases, H1 antihistamines, H2 antihistamines, antileukotrienes, and corticosteroids constitute the main pharmacologic treatment modalities. In severe and recalcitrant cases of chronic and autoimmune urticaria, immunosuppressive drugs have been used, most commonly cyclosporin. More recent experimental studies have also suggested that omalizumab, an anti-IgE therapy, may be of benefit. Currently, inhibitors of Syk are also being developed and tested in the laboratory and in animal models. As our understanding of the pathogenesis of idiopathic urticaria increases, development of additional drugs targeting these pathways may provide relief for the significant physical and psychological morbidity experienced by patients with this disorder.

Nine-year follow-up of children with atopic dermatitis by general practitioners

The frequency of associated comorbidity and the cost of treatments in patients with atopic dermatitis (AD) followed up in primary care settings are poorly known. We carried out a retrospective cohort study on a longitudinal electronic medical records database of patients consulting a panel of general practitioners in France. All subjects with AD diagnosed during the first year of life were selected and matched with infants without the disease according to sex (1,163 vs. 1,163). Subjects were followed up for 9 years. Associated diseases, drug consumptions and available medical costs were detailed. Comparisons between subjects and controls were carried out. Subjects with AD had more comorbidities than others, especially in respiratory and ophthalmic system organs. The number of prescribed treatments in the field of skin diseases as well as overall medical costs (general practitioner consultations and prescribed drugs) were higher among atopic subjects, but differences were attenuated with age.

Efficacy of Probiotic Therapy on Atopic Dermatitis in Children: A Randomized, Double-blind, Placebo-controlled Trial

Purpose

To evaluate a therapeutic efficacy of probiotics mixture (probiotics) in the treatment of children with mild-to-moderate atopic dermatitis (AD).

Methods

Randomized, double-blind, placebo-controlled, parallel trial with a washout period of 2 weeks and an intervention period for 6 weeks, conducted from November 2010 to October 2011. One hundred children with mild to moderate AD (2-9 years old) were randomly allocated to the probiotics (Lactobacilluss casei, Lactobacillus rhamnosus, Lactobacillus plantarum, and Bifidobacterium lactis) or placebo groups. The assessment of efficacy was based on the change in eczema area severity index (EASI), visual analogue scale for pruritus (VASP), fecal cell counts of each strains (log10[cell counts/g stool]), and serum cytokine levels (Interleukin-4 [IL-4]; IL-10; Tumor necrosis factor alpha, [TNF-α]) in weeks 0 and 6.

Results

Demographics and baseline characteristics at the week 0 were not significantly different between the 2 groups. The significant increments in fecal-cell counts were observed in the probiotcs group at week 6 (P=0.00), while the cytokine levels between the 2 groups were not significantly different in week 6 (IL-4, P=0.50; IL-10, P=0.58; TNF-α, P=0.82). The probiotics significantly improved clinical severity after 6 weeks' intervention of probiotics; however, the placebo group also showed significant improvement (EASI; P=0.00, VASP; P=0.00).

Conclusions

Our findings showed that probiotics successfully colonized in the intestine after 6 weeks' intervention; nevertheless, we could not find an additional therapeutic or immunomodulatory effects on the treatment of AD. Further long-term studies will be necessary to clarify the therapeutic efficacy of probiotics.

The practical understanding and treatment of asthma

Asthma is a syndrome which is seen by physicians in nearly every specialty and affects millions of people throughout the world. Although the geoepidemiology with respect to prevalence and incidence of asthma does vary, even under the most mild of circumstance, asthma is among the leading causes of school absenteeism, work loss, and physician visits. In the past, it was considered primarily a disorder of childhood. Hence, the adage that children outgrow their asthma. We now realize that children really only outgrow their pediatrician and the genetic predisposition to asthma and bronchial hyperactivity persists throughout life. This issue is devoted to key papers that focus on important clinical problems in allergies and asthma. This issue is dedicated to helping the many sufferers of asthma with the hope that this topic will eventually become a medical anachronism.

Novel challenges for the allergist

The last years have witnessed novel findings with exciting developments in the field of allergy-related diseases including asthma, bronchial hyperresponsiveness, eczema, and atopy that have enormously increased over the past few years. This issue of the Reviews is timely dedicated to comprehensive articles discussing the current trends in the study of these conditions. In particular, the impact of new data in genomics, environmental factors through epigenetics and proteomics will be reviewed and critically discussed.