What's new in atopic eczema?

Biofunctional Inorganic Layered Double Hydroxide Nanohybrid Enhances Immunotherapeutic Effect on Atopic Dermatitis Treatment

Atopic dermatitis (AD) is a widespread, recurrent, and chronic inflammatory skin condition that imposes a major burden on patients. Conventional treatments, such as corticosteroids, are associated with various side effects, underscoring the need for innovative therapeutic approaches. In this study, the possibility of using indole-3-acetic acid-loaded layered double hydroxides (IAA-LDHs) is evaluated as a novel treatment for AD. IAA is an auxin-class plant hormone with antioxidant and anti-inflammatory effects. Following the synthesis of IAA-LDH nanohybrids, their ability to induce M2-like macrophage polarization in macrophages obtained from mouse bone marrow is assessed. The antioxidant activity of IAA-LDH is quantified by assessing the decrease in intracellular reactive oxygen species levels. The anti-inflammatory and anti-atopic characteristics of IAA-LDH are evaluated in a mouse model of AD by examining the cutaneous tissues, immunological organs, and cells. The findings suggest that IAA-LDH has great therapeutic potential as a candidate for AD treatment based on its in vitro and in vivo modulation of AD immunology, enhancement of macrophage polarization, and antioxidant activity. This inorganic drug delivery technology represents a promising new avenue for the development of safe and effective AD treatments.

A review on natural biopolymers in external drug delivery systems for wound healing and atopic dermatitis

Despite the advantages of topical administration in the treatment of skin diseases, current marketed preparations face the challenge of the skin's barrier effect, leading to low therapeutic effectiveness and undesirable side effects. Hence, in recent years the management of skin wounds, the main morbidity-causing complication in hospital environments, and atopic dermatitis, the most common inflammatory skin disease, has become a great concern. Fortunately, new, more effective, and safer treatments are already under development, with chitosan, starch, silk fibroin, agarose, hyaluronic acid, alginate, collagen, and gelatin having been used for the development of nanoparticles, liposomes, niosomes and/or hydrogels to improve the delivery of several molecules for the treatment of these diseases. Biocompatibility, biodegradability, increased viscosity, controlled drug delivery, increased drug retention in the epidermis, and overall mitigation of adverse effects, contribute to an effective treatment, additionally providing intrinsic antimicrobial and wound healing properties. In this review, some of the most recent success cases of biopolymer-based drug delivery systems as part of nanocarriers, semi-solid hydrogel matrices, or both (hybrid systems), for the management of skin wounds and atopic dermatitis, are critically discussed, including composition and in vitro, ex vivo and in vivo characterization, showing the promise of these external drug delivery systems.

Extract from Black Soybean Cultivar A63 Extract Ameliorates Atopic Dermatitis-like Skin Inflammation in an Oxazolone-Induced Murine Model

Black soybean has been used in traditional medicine to treat inflammatory diseases, cancer, and diabetes and as a nutritional source since ancient times. We found that Korean black soybean cultivar A63 has more cyanidin-3-O-glucoside, (C3G), procyanidin B2 (PB2), and epicatechin (EPC) contents than other cultivars and has beneficial effects on cell viability and anti-oxidation. Given the higher concentration of anthocyanidins and their strong anti-oxidant activity, we predicted that A63 extract could relieve inflammatory disease symptoms, including those of atopic dermatitis (AD). Here, we evaluated the anti-AD activity of A63 extract in an oxazolone (OXA)-induced mouse model. A63 extract treatment significantly reduced epidermal thickness and inflammatory cell infiltration, downregulated the expression of AD gene markers, including Interleukin (IL)-4 and IL-5, and restored damaged skin barrier tissues. Furthermore, A63 extract influenced the activation of the signal transducer and activator of transcription (STAT) 3 and STAT6, extracellular regulatory kinase (ERK), and c-Jun N-terminal kinase (JNK) signaling pathways, which play a crucial role in the development of AD. Altogether, our results suggest that A63 can ameliorate AD-like skin inflammation by inhibiting inflammatory cytokine production and STAT3/6 and Mitogen-activated protein kinase (MAPK) signaling and restoring skin barrier function.

Atopic Dermatitis-Beyond the Skin

Atopic dermatitis is a chronic inflammatory disease that can arise during the first months of life or at maturity and have a significant negative impact on the quality of life. The main pathogenic mechanism is the breakdown of cutaneous barrier integrity, which is associated with systemic inflammatory immunologic disorders. Atopic dermatitis involves numerous immunologic, allergic, respiratory, and ophthalmologic comorbidities that develop through similar intricate pathogenic phenomena. The atopic march represents the evolution in time of various allergic diseases, of which food allergies often cause the first manifestations of atopy, even from a very young age. Chronic inflammation translated through specific markers, next to increased immunoglobulin E (IgE) serum levels and heterogenous clinical manifestations, argue for the inclusion of atopic dermatitis in the systemic disease category.

Staphylococcus aureus and the Cutaneous Microbiota Biofilms in the Pathogenesis of Atopic Dermatitis

Biofilm is the dominant mode of growth of the skin microbiota, which promotes adhesion and persistence in the cutaneous microenvironment, thus contributing to the epidermal barrier function and local immune modulation. In turn, the local immune microenvironment plays a part in shaping the skin microbiota composition. Atopic dermatitis (AD) is an immune disorder characterized by a marked dysbiosis, with a sharp decline of microbial diversity. During AD flares biofilm-growing Staphylococcus aureus emerges as the major colonizer in the skin lesions, in strict association with disease severity. The chronic production of inflammatory cytokines in the skin of AD individuals concurs at supporting S. aureus biofilm overgrowth at the expense of other microbial commensals, subverting the composition of the healthy skin microbiome. The close relationship between the host and microbial biofilm resident in the skin has profound implications on human health, making skin microbiota an attractive target for the therapeutic management of different skin disorders.

Antimicrobial stewardship and infection prevention and control in atopic dermatitis in children

Atopic dermatitis is a chronic, recurrent inflammatory skin disease, characterized by frequent exacerbations that can necessitate increased antibiotic use. A qualitative study was conducted at a specialist pediatric hospital to explore the perceptions of dermatology nurses on their role in antimicrobial stewardship when caring for children with atopic dermatitis. Thematic and content analysis derived that the awareness of nurses on antimicrobial stewardship was low, although they were implementing key elements in their clinical practice.

Ursolic acid downregulates thymic stromal lymphopoietin through the blockade of intracellular calcium/caspase‑1/NF‑κB signaling cascade in HMC‑1 cells

Thymic stromal lymphopoietin (TSLP) plays an important role in allergic disorders, including atopic dermatitis and asthma. Ursolic acid (UA) has various pharmacological properties, such as antioxidant, anti‑inflammatory and anticancer. However, the effect of UA on TSLP regulation has not been fully elucidated. The aim of the present study was to analyze how UA regulates the production of TSLP in the human mast cell line HMC‑1. Enzyme‑linked immunosorbent assay, quantitative polymerase chain reaction analysis, western blotting, caspase‑1 assay and fluorescent measurements of intracellular calcium levels were conducted to analyze the regulatory effects of UA. The results revealed that UA inhibited TSLP production and mRNA expression. In addition, UA reduced the activation of nuclear factor‑κB and degradation of IκBα. Caspase‑1 activity was increased by exposure to phorbol myristate acetate plus calcium ionophore, whereas it was reduced by UA. Finally, UA treatment prevented an increase in intracellular calcium levels. These results indicated that UA may be a useful agent for the treatment and/or prevention of atopic and inflammatory diseases, and its effects are likely mediated by TSLP downregulation.

Effects of Linalyl Acetate on Thymic Stromal Lymphopoietin Production in Mast Cells

Thymic stromal lymphopoietin (TSLP) is an important factor responsible for the pathogenesis of allergic diseases, such as atopic dermatitis and asthma. Because linalyl acetate (LA) possesses a wide range of pharmacological properties, being antispasmodic, anti-inflammatory, and anti-hyperpigmentation, we hypothesized that LA could inhibit TSLP. Therefore, enzyme-linked immunosorbent assay, quantitative polymerase chain reaction, caspase-1 assay, Western blot analysis, fluorescent analyses of the intracellular calcium levels, and the phorbol myristate acetate (PMA)-induced edema model were used to investigate how LA inhibits the production of TSLP in HMC-1 cells. LA reduced the production and mRNA expression of TSLP in HMC-1 cells. LA also inhibited the activation of nuclear factor-κB and degradation of IκBα. PMA plus A23187 stimulation up-regulated caspase-1 activity in HMC-1 cells; however, this up-regulated caspase-1 activity was down-regulated by LA. Finally, LA decreased intracellular calcium levels in HMC-1 cells as well as PMA-induced ear swelling responses in mice. Taken together, these results suggest that LA would be beneficial to treatment of atopic and inflammatory diseases by reducing TSLP.

Allergic Responses Induced by the Immunomodulatory Effects of Nanomaterials upon Skin Exposure

Over the past decade, a vast array of nanomaterials has been created through the development of nanotechnology. With the increasing application of these nanomaterials in various fields, such as foods, cosmetics, and medicines, there has been concern about their safety, that is, nanotoxicity. Therefore, there is an urgent need to collect information about the biological effects of nanomaterials so that we can exploit their potential benefits and design safer nanomaterials, while avoiding nanotoxicity as a result of inhalation or skin exposure. In particular, the immunomodulating effect of nanomaterials is one of most interesting aspects of nanotoxicity. However, the immunomodulating effects of nanomaterials through skin exposure have not been adequately discussed compared with the effects of inhalation exposure, because skin penetration by nanomaterials is thought to be extremely low under normal conditions. On the other hand, the immunomodulatory effects of nanomaterials via skin may cause severe problems for people with impaired skin barrier function, because some nanomaterials could penetrate the deep layers of their allergic or damaged skin. In addition, some studies, including ours, have shown that nanomaterials could exhibit significant immunomodulating effects even if they do not penetrate the skin. In this review, we summarize our current knowledge of the allergic responses induced by nanomaterials upon skin exposure. First, we discuss nanomaterial penetration of the intact or impaired skin barrier. Next, we describe the immunomodulating effects of nanomaterials, focusing on the sensitization potential of nanomaterials and the effects of co-exposure of nanomaterials with substances such as chemical sensitizers or allergens, on the onset of allergy, following skin exposure. Finally, we discuss the potential mechanisms underlying the immunomodulating effects of nanomaterials by describing the involvement of the protein corona in the interaction of nanomaterials with biological components and by presenting recent data about the adjuvant effects of well-characterized particle adjuvant, aluminum salt, as an example of immunomodulatory particulate.

Nonsteroidal Topical Immunomodulators in Allergology and Dermatology

The purpose of this study was to review currently available literature data concerning pathomechanisms of action, indications, treatment efficacy, as well as side effects of nonsteroidal immunomodulators used in dermatology, primarily for the treatment of allergic dermatoses. MEDLINE search was undertaken using the key words “Topical Immunomodulators, Dermatology and Allergy”. Full articles, and nothing but full articles, were used.

Association Between Atopic Dermatitis and Autism Spectrum Disorders: A Systematic Review

BACKGROUND

Atopic dermatitis (AD) is an allergic disorder caused by both immunological dysregulation and epidermal barrier defect. Several studies have investigated the association between AD and mental health disorders. Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental conditions characterized by impairments in social communication and restricted, stereotyped interests and behaviors. The concurrent increased prevalence of AD and ASD in the last decades has led many scientists to investigate the relationship between the two diseases.

OBJECTIVE

The aim of this systematic review was to examine the association between AD and ASD.

METHODS

A systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed and ScienceDirect were searched up to March 2015 for all reports examining the association between ASD and AD. Descriptive statistics of the studies are reported.

RESULTS

The review included 18 studies assessing the association between ASD and AD. Of these studies, two focused on ASD in relation to AD alone, 14 discussed ASD in relation to both AD and other atopic disorders, and two evaluated AD in parents of children with ASD. Most of these studies found a positive association between the two disorders, although there were some studies going in the opposite direction. The entity of the association is somewhat inconsistent among the different studies given that the frequencies of AD in ASD compared with a control group ranged from 7 to 64.2%. In addition, odds ratios (ORs) or hazard ratios (HRs) gave different results as three studies found a weak association with an OR below 2 and a nonsignificant p value, and three other studies found a moderate or strong association with an OR ranging from 1.52 to 7.17 and a significant p value. When all atopic disorders were considered when evaluating the risk of ASD, the association was strong with an HR of 3.4 or an OR of 1.24 and p < 0.001.

CONCLUSIONS

Overall, the results of this systematic review seem to reveal an association between ASD and AD, suggesting that subjects with ASD have an increased risk of presenting with AD compared with typically developing controls, and vice versa. This association is supported by clinical/epidemiological aspects, shared genetic background and common immunological and autoimmune processes. However, the variability in study population and design, and the presence of other risk factors acting as confounding factors, sometimes contribute to inconsistent results. Further studies are needed to clarify the underlying pathophysiologic mechanism explaining the association between ASD and AD and to explore the causal association between the two conditions.

Prenatal air pollutant exposure and occurrence of atopic dermatitis

BACKGROUND

Hereditary and environmental factors have been related to the occurrence of atopic dermatitis (AD) in early childhood. However, the role of prenatal and early postnatal exposure to air pollutants has not been totally elucidated.

OBJECTIVES

To evaluate the association between prenatal air pollutant exposure and occurrence of AD.

METHODS

In total 24 200 infant-mother pairs were recruited to participate in the Taiwan Birth Cohort Study in 2005 using multistage stratified sampling. Medical history, including physician-diagnosed AD, was inquired by questionnaire at the infant's age of 6 months. Monthly averages of five criteria air pollutants - NO2 , CO, O3 , SO2 and PM10 - were retrieved from 66 air-quality-monitoring stations, and interpolated to all administrative districts using the kriging method. Exposure data during each of the three gestational trimesters and three months after birth were calculated for each study subject, and odds ratios (ORs) of AD occurrence were calculated by logistic regression.

RESULTS

Among the participants, 16 686 mother-infant pairs were qualified for and included in the analysis. Among them, 1206 infants (7·2%) had been diagnosed as having AD before the age of 6 months, and the prevalence was higher in boys (8·3%) than in girls (6·1%). The occurrence of AD was significantly associated with CO exposure during the whole gestational period [adjusted OR (aOR) 1·37, 95% confidence interval (CI) 1·06-1·78] and the first trimester (aOR 1·51, 95% CI 1·16-1·97). We did not observe any significant association among the other air pollutants during either the whole gestational period or any period of the three trimesters and 3 months after birth.

CONCLUSIONS

Our study found a relationship between AD occurrence and gestational exposure to CO, where exposure during the first trimester seemed to be the most important.

Atopic dermatitis as a systemic disease

Atopic dermatitis (AD) is a chronic inflammatory disease that seriously affects the quality of life of these patients. Both immune deviations and epidermal barrier deficiency have been defined as pathophysiologic mechanisms in the disease development. The atopic march, or the natural progression form atopic dermatitis in infancy to asthma and allergic rhinitis, is a classic example for the multiorgan involvement in atopy. It has been hypothesized that epidermal barrier impairment is the primary pathologic condition responsible for the atopic march. In recent decades, a growing body of evidence has accumulated that AD can be accompanied by a variety of systemic diseases, such as autoimmune disorders, ophthalmologic involvement, eosinophilic gastroenteritis, inflammatory bowel disease, nephritic syndrome, and metabolic diseases. This contribution reviews these associations and focuses on the possible common underlying mechanisms of AD and the associated syndromes. We present a concept on AD as a multiorgan systemic disease.

Functional diversity and pharmacological profiles of the FKBPs and their complexes with small natural ligands

From 5 to 12 FK506-binding proteins (FKBPs) are encoded in the genomes of disparate marine organisms, which appeared at the dawn of evolutionary events giving rise to primordial multicellular organisms with elaborated internal body plan. Fifteen FKBPs, several FKBP-like proteins and some splicing variants of them are expressed in humans. Human FKBP12 and some of its paralogues bind to different macrocyclic antibiotics such as FK506 or rapamycin and their derivatives. FKBP12/(macrocyclic antibiotic) complexes induce diverse pharmacological activities such as immunosuppression in humans, anticancerous actions and as sustainers of quiescence in certain organisms. Since the FKBPs bind to various assemblies of proteins and other intracellular components, their complexes with the immunosuppressive drugs may differentially perturb miscellaneous cellular functions. Sequence-structure relationships and pharmacological profiles of diverse FKBPs and their involvement in crucial intracellular signalization pathways and modulation of cryptic intercellular communication networks were discussed.

Oral evening primrose oil and borage oil for eczema

BACKGROUND

Eczema is a chronic inflammatory skin condition, which usually develops in early childhood. Many children outgrow this disorder as they reach secondary school age, and although It may improve with age, there is no cure. Constant itch makes life uncomfortable for those with this condition, no matter what age they are, so it may have a significant effect on a person's quality of life. Its prevalence seems to be increasing as populations move from rural locations to cities. Some people, who do not see an adequate improvement or fear side-effects of conventional medical products, try complementary alternatives to conventional treatment. This is a review of evening primrose oil (EPO) and borage oil (BO) taken orally (by mouth); these have been thought to be beneficial because of their gamma-linolenic acid content.

OBJECTIVES

To assess the effects of oral evening primrose oil or borage oil for treating the symptoms of atopic eczema.

SEARCH METHODS

We searched the following databases up to August 2012: Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 1946), EMBASE (from 1974), AMED (from 1985), and LILACS (from 1982). We also searched online trials registers and checked the bibliographies of included studies for further references to relevant trials. We corresponded with trial investigators and pharmaceutical companies to try to identify unpublished and ongoing trials. We performed a separate search for adverse effects of evening primrose oil and borage oil in November 2011.

SELECTION CRITERIA

All randomised controlled, parallel, or cross-over trials investigating oral intake of evening primrose oil or borage oil for eczema.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied eligibility criteria, assessed risk of bias, and extracted data. We pooled dichotomous outcomes using risk ratios (RR), and continuous outcomes using the mean difference (MD). Where possible, we pooled study results using random-effects meta-analysis and tested statistical heterogeneity using both the Chi(²) test and the I(²) statistic test. We presented results using forest plots with 95% confidence intervals (CI).

MAIN RESULTS

A total of 27 studies (1596 participants) met the inclusion criteria: 19 studies assessed evening primrose oil, and 8 studies assessed borage oil. For EPO, a meta-analysis of results from 7 studies showed that EPO failed to significantly increase improvement in global eczema symptoms as reported by participants on a visual analogue scale of 0 to 100 (MD -2.22, 95% CI -10.48 to 6.04, 176 participants, 7 trials) and a visual analogue scale of 0 to 100 for medical doctors (MD -3.26, 95% CI -6.96 to 0.45, 289 participants, 8 trials) compared to the placebo group.Treatment with BO also failed to significantly improve global eczema symptoms compared to placebo treatment as reported by both participants and medical doctors, although we could not conduct a meta-analysis as studies reported results in different ways. With regard to the risk of bias, the majority of studies were of low risk of bias; we judged 67% of the included studies as having low risk of bias for random sequence generation; 44%, for allocation concealment; 59%, for blinding; and 37%, for other biases.

IMPLICATIONS FOR PRACTICE

Oral borage oil and evening primrose oil lack effect on eczema; improvement was similar to respective placebos used in trials. Oral BO and EPO are not effective treatments for eczema.In these studies, along with the placebos, EPO and BO have the same, fairly common, mild, transient adverse effects, which are mainly gastrointestinal.The short-term studies included here do not examine possible adverse effects of long-term use of EPO or BO. A case report warned that if EPO is taken for a prolonged period of time (more than one year), there is a potential risk of inflammation, thrombosis, and immunosuppression; another study found that EPO may increase bleeding for people on Coumadin® (warfarin) medication.

IMPLICATIONS FOR RESEARCH

Noting that the confidence intervals between active and placebo treatment are narrow, to exclude the possibility of any clinically useful difference, we concluded that further studies on EPO or BO for eczema would be hard to justify.This review does not provide information about long-term use of these products.

New era of biologic therapeutics in atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a common inflammatory skin disease regulated by genetic and environmental factors. Both skin barrier defects and aberrant immune responses are believed to drive cutaneous inflammation in AD. Existing therapies rely largely on allergen avoidance, emollients and topical and systemic immune-suppressants, some with significant toxicity and transient efficacy; no specific targeted therapies are in clinical use today. As our specific understanding of the immune and molecular pathways that cause different subsets of AD increases, a variety of experimental agents, particularly biologic agents that target pathogenic molecules bring the promise of safe and effective therapeutics for long-term use.

AREAS COVERED

This paper discusses the molecular pathways characterizing AD, the contributions of barrier and immune abnormalities to its pathogenesis, and development of new treatments that target key molecules in these pathways. In this review, we will discuss a variety of biologic therapies that are in development or in clinical trials for AD, perhaps revolutionizing treatment of this disease.

EXPERT OPINION

Biologic agents in moderate to severe AD offer promise for controlling a disease that currently lacks good and safe therapeutics posing a large unmet need. Unfortunately, existing treatments for AD aim to decrease cutaneous inflammation, but are not specific for the pathways driving this disease. An increasing understanding of the immune mechanisms underlying AD brings the promise of narrow targeted therapies as has occurred for psoriasis, another inflammatory skin disease, for which specific biologic agents have been demonstrated to both control the disease and prevent occurrence of new skin lesions. Although no biologic is yet approved for AD, these are exciting times for active therapeutic development in AD that might lead to revolutionary therapeutics for this disease.

Management of patients with atopic dermatitis: the role of emollient therapy

Atopic dermatitis is a common inflammatory skin disorder that afflicts a growing number of young children. Genetic, immune, and environmental factors interact in a complex fashion to contribute to disease expression. The compromised stratum corneum found in atopic dermatitis leads to skin barrier dysfunction, which results in aggravation of symptoms by aeroallergens, microbes, and other insults. Infants—whose immune system and epidermal barrier are still developing—display a higher frequency of atopic dermatitis. Management of patients with atopic dermatitis includes maintaining optimal skin care, avoiding allergic triggers, and routinely using emollients to maintain a hydrated stratum corneum and to improve barrier function. Flares of atopic dermatitis are often managed with courses of topical corticosteroids or calcineurin inhibitors. This paper discusses the role of emollients in the management of atopic dermatitis, with particular emphasis on infants and young children.

Effects of schizandrin on the expression of thymic stromal lymphopoietin in human mast cell line HMC-1

AIMS

Thymic stromal lymphopoietin (TSLP) plays an important role in allergic diseases such as asthma and atopic dermatitis. Schizandrin has various effects such as anti-asthmatic, anti-cancer and anti-inflammatory effects. However, the effect of schizandrin on the production of TSLP has not been clarified. Thus, we investigated how schizandrin inhibits the production of TSLP in the human mast cell line HMC-1 cells.

MAIN METHODS

We used enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction, luciferase assay, and Western blot analysis to investigate the effects of schizandrin.

KEY FINDINGS

Schizandrin inhibited the production and mRNA expression of TSLP in HMC-1 cells. The maximal inhibition rate of TSLP production by schizandrin (10 μM) was 68.62 ± 3.47%. Schizandrin inhibited the translocation and luciferase activity of nuclear factor-κB induced by phorbol myristate acetate plus A23187. In the activated HMC-1 cells, the activation of caspase-1 was increased, whereas the activation of caspase-1 was decreased by pretreatment with schizandrin.

SIGNIFICANCE

These results suggest that schizandrin can be used to treat inflammatory and atopic diseases through the inhibition of TSLP.

Amorphous silica nanoparticles size-dependently aggravate atopic dermatitis-like skin lesions following an intradermal injection

Background

Due to the rising use of nanomaterials (NMs), there is concern that NMs induce undesirable biological effects because of their unique physicochemical properties. Recently, we reported that amorphous silica nanoparticles (nSPs), which are one of the most widely used NMs, can penetrate the skin barrier and induce various biological effects, including an immune-modulating effect. Thus, it should be clarified whether nSPs can be a risk factor for the aggravation of skin immune diseases. Thus, in this study, we investigated the relationship between the size of SPs and adjuvant activity using a model for atopic dermatitis.

Results

We investigated the effects of nSPs on the AD induced by intradermaly injected-mite antigen Dermatophagoides pteronyssinus (Dp) in NC/Nga mice. Ear thickness measurements and histopathological analysis revealed that a combined injection of amorphous silica particles (SPs) and Dp induced aggravation of AD in an SP size-dependent manner compared to that of Dp alone. In particular, aggravation was observed remarkably in nSP-injected groups. Furthermore, these effects were correlated with the excessive induction of total IgE and a stronger systemic Th2 response. We demonstrated that these results are associated with the induction of IL-18 and thymic stromal lymphopoietin (TSLP) in the skin lesions.

Conclusions

A particle size reduction in silica particles enhanced IL-18 and TSLP production, which leads to systemic Th2 response and aggravation of AD-like skin lesions as induced by Dp antigen treatment. We believe that appropriate regulation of nanoparticle physicochemical properties, including sizes, is a critical determinant for the design of safer forms of NMs.

Topical fluticasone propionate: intervention and maintenance treatment options of atopic dermatitis based on a high therapeutic index

Fluticasone propionate (FP), a medium potent glucocorticoid (class III) of carbothioate nature with a favourable benefit/risk ratio, has emerged as a standard medication for the topical treatment of inflammatory skin disorders, in particular atopic dermatitis (AD). FP is available as a 0.05% cream and a 0.005% ointment formulation. The glucocorticoid is characterized by high lipophilicity, high affinity binding to the glucocorticoid receptor and a rapid hepatic biotransformation. Though skin blanching following topical application of FP surpasses that given with glucocorticoids of medium strength, clinical trials show a low potential of FP for local and systemic adverse effects. Even in paediatric patients with AD as well as in difficult-to-treat areas like face, eyelids and intertriginous areas, FP proved to be both effective and safe. Thus, the therapeutic effects of FP clearly outweigh the unwanted effects. Correspondingly, a therapeutic index of 2.0 can be attributed to this glucocorticoid. In this respect, topical FP does not differ from other topical glucocorticoids with increased benefit-to-risk ratio, e.g. prednicarbate, methylprednisolone aceponate and mometasone furoate. However, randomized controlled trials do not only support conventional intervention but also innovative maintenance treatment.

Naringenin suppresses the production of thymic stromal lymphopoietin through the blockade of RIP2 and caspase-1 signal cascade in mast cells

Thymic stromal lymphopoietin (TSLP) plays a critical role in allergic diseases such as atopic dermatitis, asthma, and chronic obstructive pulmonary disease. Naringenin has various effects such as anti-atherogenic, anti-oxidant, and anti-inflammatory effects. However, the effect of naringenin on the production of TSLP has not been clarified. Thus, we investigated how naringenin inhibits the production of TSLP in the human mast cell line (HMC-1) cells. Naringenin inhibited the production and mRNA expression of TSLP in HMC-1 cells. The maximal inhibition rate of TSLP production by naringenin (100 μM) was 62.27 ± 10.79%. Naringenin also inhibited the nuclear factor-κB luciferase activity induced by phorbol myristate acetate plus A23187. In the activated HMC-1 cells, the activations of receptor-interacting protein (RIP)2 and caspase-1 were increased, whereas the activations of RIP2 and caspase-1 were decreased by pretreatment with naringenin. These results suggest that naringenin can be used to treat inflammatory and atopic diseases through the inhibition of TSLP.

Berberine inhibits the production of thymic stromal lymphopoietin by the blockade of caspase-1/NF-κB pathway in mast cells

Thymic stromal lymphopoietin (TSLP) plays a pivotal role in allergic diseases such as atopic dermatitis, asthma, and chronic obstructive pulmonary disease. However, it has not been clarified the effect of berberine (BER) on the production of TSLP yet. Thus, we investigated how BER inhibits the production of TSLP in the human mast cell line (HMC-1) cells. We used enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction, luciferase assay, and Western blot analysis to investigate the effects of BER. BER inhibited the production and mRNA expression of TSLP in HMC-1 cells. BER also inhibited the nuclear factor-κB luciferase activity induced by phorbol myristate acetate plus A23187. BER inhibited the activation of caspase-1 in HMC-1 cells. Furthermore, BER inhibited the production of TSLP in primary mast cells. These results provide evidence that BER can help to treat inflammatory and atopic diseases through the inhibition of TSLP.

Epigallocatechin-3-O-gallate inhibits the production of thymic stromal lymphopoietin by the blockade of caspase-1/NF-κB pathway in mast cells

The cytokine thymic stromal lymphopoietin (TSLP) has been implicated in the development and progression of allergic diseases such as atopic dermatitis, asthma, and chronic obstructive pulmonary disease. However, it has not yet been clarified the effect of epigallocatechin-3-O-gallate (EGCG) on the production of TSLP. Thus, we investigated how EGCG inhibits the production of TSLP in the human mast cell line (HMC-1) cells. Enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction, luciferase assay, and Western blot analysis were used to investigate the effects of EGCG. EGCG inhibited the production and mRNA expression of TSLP in HMC-1 cells. EGCG also inhibited the nuclear factor-κB luciferase activity induced by phorbol myristate acetate plus A23187. Furthermore, EGCG inhibited the activation of caspase-1 in HMC-1 cells. These results provide evidence that EGCG can help us to treat inflammatory and atopic diseases through the inhibition of TSLP.

Thymic stromal lymphopoietin is expressed and produced by caspase-1/NF-κB pathway in mast cells

Thymic stromal lymphopoietin (TSLP) plays a pivotal role in allergic diseases such as atopic dermatitis, asthma, and chronic obstructive pulmonary disease. Although there are many reports regarding function and regulatory mechanism of TSLP in dendritic cells and/or T cells, the regulatory mechanism of TSLP in mast cells has not been fully elucidated. Here, we describe how TSLP is expressed and produced by inflammatory stimulus in mast cells. TSLP mRNA was expressed by phorbol myristate acetate (PMA) plus A23187 stimulation in HMC-1 cells and reached its peak 5h after PMA plus A23187 stimulation. The expression of TSLP mRNA was inhibited by nuclear factor (NF)-κB inhibitor. In addition, NF-κB luciferase activity was inhibited by caspase-1 inhibitor, indicating that caspase-1 is an upstream of NF-κB in mast cells. Furthermore, caspase-1 inhibitor decreased the expression of TSLP mRNA induced by PMA plus A23187. Finally, TSLP production was inhibited by both caspase-1 inhibitor and NF-κB inhibitor. These results provide proof of principle that TSLP can be expressed and produced through caspase-1 and NF-κB in mast cells and open new perspectives to pharmacologically manipulate the expression and production of TSLP by molecules acting on the caspase-1 and NF-κB pathway.