Osthole attenuates mouse atopic dermatitis by inhibiting thymic stromal lymphopoietin production from keratinocytes

Atopic dermatitis is one of the most common skin diseases. Dysregulation of immune system and chronic inflammation were believed to be associated with atopic dermatitis. Osthole was reported to play important roles in antitumor and anti‐inflammation. However, whether osthole has effects on atopic dermatitis remains unclear. In this present study, we explored the biological role of osthole in atopic dermatitis and the molecular mechanism. Atopic dermatitis was induced by 2,4‐dinitrochlorobenzene. Pathological damage of ear was detected by H&E staining. IgE level in serum or thymic stromal lymphopoietin (TSLP) level in supernatant was detected by ELISA. Interleukin (IL)‐4 expression and IL‐13 expression in CD4⁺ T cells were detected using flow cytometry. The expression levels of mRNA or protein levels were detected by RT‐PCR or Western blot. Osthole attenuated atopic dermatitis development in mouse model. Osthole inhibits Th2 cell response, but have on influence on Th1 or Th17 cell response in the skin. In mouse model, osthole treatment significantly inhibited atopic dermatitis via directly inhibiting TLSP expression levels in keratinocytes. Osthole treatment alleviates atopic dermatitis through directly down‐regulating TSLP production from keratinocytes. Osthole may serve as a potential choice for atopic dermatitis treatment in clinic.     

A novel mouse model of atopic dermatitis with epicutaneous allergen sensitization and the effect of Lactobacillus rhamnosus

Atopic dermatitis (AD) is a chronic and relapsing inflammatory skin disease, and the pathogenesis is not completely understood. Although there are some mouse models of AD, it is not easy to establish model to represent the natural AD development in human. In this study, we developed an AD model based on outside–inside theory and investigated the effect of Lactobacillus rhamnosus (Lcr35), which have known as an immune modulator in allergic diseases. SKH‐1 hairless mice underwent three 1‐week exposures (separated by 2‐week intervals) to an ovalbumin (OVA) or saline (control) patch at the same site to develop the mouse model of AD. Lcr35 (1 × 10⁹ CFU) was administered orally every day from 1 week before the first sensitization until the end of the study. The AD model induced erythematous and itchy skin, increasing TEWL and increasing skin inflammation as assessed by histology in the mice. Oral Lcr35 attenuated all disease parameters previously mentioned. OVA‐specific IgE and skin expression of interleukin‐4 (IL‐4) and thymic stromal lymphopoietin (TSLP) increased in AD mice, but were reduced in AD mice treated with Lcr35. Moreover, Lcr35 treatment led to an increase in CD4⁺CD25⁺ Foxp3⁺ Treg cells in the mesenteric lymph nodes of AD mice. In conclusions, based on the ‘outside–inside’ theory, topical allergen may induce AD without skin injury. Oral application of Lcr35 prevented the development of AD in this model by suppressing production of the inflammatory cytokines, IL‐4 and TSLP in the skin via a mechanism that may involve CD4⁺CD25⁺Foxp3⁺Treg cells.     

上皮源性细胞因子白细胞介素33、白细胞介素25和胸腺基质淋巴细胞生成素在特应性皮炎发病机制中的作用

【摘要】 表皮屏障功能缺陷及免疫改变是特应性皮炎（AD）发生发展的主要病理生理改变,而皮肤角质形成细胞在各种损伤因素作用下可释放多种炎症因子和介质,其中3种上皮源性因子白细胞介素33、白细胞介素25、胸腺基质淋巴细胞生成素被认为是皮肤或黏膜屏障Th2型免疫应答的有效诱导因子,能够激活免疫细胞,引起Th2型细胞因子分泌,增强Th2型免疫应答,参与AD的发生与发展。本文就3种上皮源性细胞因子在AD发病机制中的作用进展进行总结。     

Suppressive effect of mangosteen rind extract on the spontaneous development of atopic dermatitis in NC/Tnd mice

Atopic dermatitis (AD) is a chronic and relapsing skin disorder characterized by pruritic and dry skin lesions with allergic inflammation. Recent studies have revealed anti‐inflammatory and anti‐allergic effects of xanthones in mangosteen through regulation of the nuclear factor (NF)‐κB signaling pathway. Activation of NF‐κB signals is responsible for allergic inflammation in AD. To develop a new preventive therapy for AD, we examined the effects of the natural medicine, mangosteen rind extract (ME), on AD in a murine model. ME (250 mg/kg per day) was administrated to NC/Tnd mice, a model for human AD, for 6 weeks to evaluate its preventive effects on AD. We also confirmed the effects of ME on various immune cell functions. Oral administration of ME prevented the increase of clinical skin severity scores, plasma total immunoglobulin E levels, scratching behavior, transepidermal water loss and epidermal hyperplasia in NC/Tnd mice; moreover, no adverse effects were noted. We demonstrated that ME suppressed thymic stromal lymphopoietin and interferon‐γ mRNA expression both in vitro and in vivo. Not only immunoglobulin E production from splenic B cells but also immunoglobulin E‐mediated degranulation of bone marrow‐derived cultured mast cells was significantly reduced by the addition of ME to the culture. In addition, mRNA expression levels of nerve growth factor were decreased in ME‐administrated NC/Tnd mice compared with those of controls. Keratinocyte proliferation was well‐controlled by ME application. Oral administration of ME exhibited its suppressive potential on the early development of AD by controlling inflammation, itch and epidermal barrier function.     

窄谱中波紫外线对特应性皮炎患者外周血血清胸腺基质淋巴细胞生成素、白细胞介素25及其受体的影响

目的 探讨窄谱中波紫外线（NB-UVB）对特应性皮炎（AD）患者血清胸腺基质淋巴细胞生成素（TSLP）、白细胞介素25（IL-25）及外周血单一核细胞（PBMC）TSLP受体（TSLPR）mRNA、IL-25受体（IL-25R）mRNA表达水平的影响。 方法 AD患者40例,采用NB-UVB照射治疗,双抗体夹心酶联免疫吸附试验（ELISA）检测治疗前后血清中TSLP、IL-25水平;反转录-聚合酶链反应（RT-PCR）法检测治疗前后PBMC TSLPR mRNA、IL-25R mRNA的表达水平。采用欧洲的AD评分标准（SCORAD）评估疾病严重程度,视觉模拟标尺法（VAS）评价瘙痒程度。选取30例健康体检者作为对照。组间比较采用两独立样本t检验,治疗前后比较采用配对t检验。 结果 患者组经NB-UVB照射后总有效率达75%（30/40）,治疗后SCORAD评分（20.36 ± 5.12）及VAS评分（3.05 ± 1.02）均较治疗前（分别为55.26 ± 10.88和8.20 ± 1.37）明显降低,差异均有统计学意义（t值分别为10.29和8.16,P < 0.05）。AD患者组治疗前血清TSLP［（198.24 ± 29.47） ng/L］、IL-25含量（160.54 ± 34.89 ng/L）及TSLPR mRNA（8.57 ± 1.34）、IL-25R mRNA（6.81 ± 0.50）相对表达量均明显高于健康对照组［分别为（120.13 ± 19.65） ng/L、（120.41 ± 43.07） ng/L、1.94 ± 0.39、1.48 ± 0.47］,差异均有统计学意义（t值分别为29.70、14.65、7.07、18.89,P < 0.05）。NB-UVB治疗显著改善病情后,患者血清TSLP［（151.87 ± 14.78） ng/L］、IL-25含量［（130.52 ± 29.65） ng/L］及PBMC TSLPR mRNA（2.89 ± 0.53）、IL-25R mRNA（3.90 ± 0.37）相对表达量较治疗前明显降低,差异均有统计学意义（t值分别为18.56、9.07、5.21、7.35,均P < 0.05）。治疗后血清TSLP、IL-25含量,PBMC TSLPR mRNA、IL-25R mRNA相对表达量与健康对照组相比,差异均无统计学意义（P > 0.05）。 结论 TSLP、IL-25可能在AD的发病中起重要作用,NB-UVB下调TSLP、IL-25及其受体的表达可能是NB-UVB治疗AD的机制之一。     

Insight into newly discovered innate immune modulation in atopic dermatitis

Atopic dermatitis (AD) is a highly pruritic, chronic relapsing inflammatory skin disease characterized by innate and adaptive immune reactions. In AD, innate immune mechanisms such as pattern recognition receptors and antimicrobial peptides have been investigated in detail, but recently, epidermis‐derived cytokines, namely thymic stromal lymphopoietin (TSLP), IL‐25 and IL‐33, were shown to participate in innate immune reactions independently of adaptive immunity. In addition to conventional innate cells, such as mast cells, basophils and eosinophils, Th2 cytokine‐producing invariant natural killer T (iNKT) cells, innate lymphoid cells (ILCs) and Th17/Th22 cytokine‐producing innate cells – iNKT cells and natural killer (NK)‐like cells – can participate in innate immune modulation in AD. Accordingly, early control of innate immune responses in AD before activation of adaptive immune responses by conventional T and B cells that perpetuate chronic skin inflammation may adequately alleviate acute exacerbations of AD. Therefore, we hypothesized that select immune modulators targeting the innate immune response could potentially be used for individualized treatment of AD.     

Eosinophil involvement in atopic dermatitis as reflected by elevated serum levels of eosinophil cationic protein.

Eosinophil cationic protein (ECP), one of the eosinophil granule proteins, is released during allergic reactions. We investigated the possibility of correlations among the serum levels of ECP, clinical activity, and eosinophil number in patients with atopic dermatitis (AD). Forty-four patients with AD and 25 normal, non-atopic subjects were studied. ECP was quantitated by a double antibody radioimmunoassay. The levels of serum ECP correlate with the grading of severity of clinical evaluations in AD. The patients with severe and moderate AD had significantly higher ECP concentrations than normal controls (p less than 0.001); mild AD had levels identical with those of control groups. A positive correlation was observed between the number of peripheral blood eosinophils and serum ECP levels in the severe cases (r = 0.67, p less than 0.05). Furthermore, these ECP levels significantly decreased in response to either improvement of clinical severity of AD or decreased numbers of blood hypodense eosinophils in anti-allergic drug-treated patients. No coefficient of correlation was observed between serum ECP and IgE levels. These findings indicate that eosinophils may release their granular contents, including ECP, into the peripheral circulation and/or inflammatory skin lesions and subsequently provoke a clinical exacerbation by stimulating allergic reactions.     

胸腺基质淋巴细胞生成素在炎症性皮肤病中的作用及相关机制研究进展

胸腺基质淋巴细胞生成素(TSLP)是一种调节皮肤粘膜炎症反应、维持免疫稳态的IL-7样细胞因子.近年来研究显示,TSLP不但在特应性皮炎、接触性皮炎等变态反应性皮肤病中发挥重要作用,也与玫瑰痤疮、银屑病、嗜酸性皮病和白塞病等多种炎症性皮肤病相关.现就TSLP的一般生物学特性、在常见炎症性皮肤病中的相关作用机制及TSLP...     

40例成人发病型特应性皮炎患者外周血嗜酸性粒细胞和血清总IgE的检测

目的:探讨外周血嗜酸性粒细胞(EOS)和血清总IgE与成人发病型特应性皮炎(AD)的关系.方法:选取首次发病年龄>18岁的40例AD患者作为病例组,30例健康成年体检者作为对照组,检测两组外周血EOS和血清总IgE水平,比较性别、年龄、外周血EOS和血清总IgE水平在病例组和对照组以及不同疾病严重程度、伴/不伴呼吸道过...     

Filaggrin knockdown and Toll-like receptor 3 (TLR3) stimulation enhanced the production of thymic stromal lymphopoietin (TSLP) from epidermal layers

Keratinocytes constitute the first-line barrier against exogenous antigens and contain Toll-like receptors (TLRs), which function as pattern-recognition molecules to activate antimicrobial innate immune responses. In an effort to ascertain whether or not filaggrin (filament-aggregating protein) expression affected the TLR-mediated responses of keratinocytes, we transfected filaggrin siRNA into HaCaT human keratinocyte cells and determined that thymic stromal lymphopoietin (TSLP) and IL-6 secretion were increased by poly(I:C) stimulus. Additionally, TSLP expression is increased in filaggrin knockdown as well as TLR3 stimulation in reconstituted human epidermal layers. Therefore, the findings of this study show that reduced filaggrin levels may influence innate immune responses via TLR stimuli and may contribute to the pathogenesis of inflammatory skin disease via TSLP expression.     

Soluble E-selectin and eosinophil cationic protein are distinct serum markers that differentially represent clinical features of atopic dermatitis

The serum levels of eosinophil cationic protein (ECP), soluble E-selectin (sE-selectin), soluble CD14 (sCD14) and interleukin (IL)-4 are known to be elevated in patients with atopic dermatitis (AD). However, little is known of the mutual relationship between these factors. To elucidate the clinical and mutual relevance of these markers, we examined the serum levels of ECP, sE-selectin, sCD14 and IL-4 as compared with eruption scores, itch scores, total IgE and numbers of peripheral eosinophils in patients with AD (n = 43), non-atopic eczema (n = 24) and urticaria (n = 13) and in normal individuals (n = 45). In 27 patients with AD the levels of these markers were compared before and after treatment. Levels of ECP were elevated only in the patients with AD, whereas the sE-selectin levels were higher not only in AD but also in non-atopic eczema in a severity-dependent manner. The levels of both markers significantly diminished after treatment. Significant correlations existed between ECP levels and numbers of eosinophils, sE-selectin levels and itch scores, and sE-selectin levels and IgE levels. No significant changes were observed in the sCD14 and IL-4 levels. Taken together, sE-selectin and ECP are good but distinct serum markers that reflect different clinical features of AD.     

No association between serum eosinophil cationic protein and atopic dermatitis or allergic rhinitis in an unselected population of children

Background In order to obtain background references when dealing with serum eosinophil cationic protein (s‐ECP) measurements in children with allergic diseases, population‐based studies are important. The objectives of our study were to explore the strength of associations between the s‐ECP level and atopic dermatitis (AD), allergic rhinitis (AR) and asthma in an unselected northern Norwegian schoolchildren population. Methods s‐ECP was sampled from 396 schoolchildren aged 7–12 years from Sør‐Varanger community, northern Norway as a part of a population‐based study of allergy. In advance, anamnestic information concerning a history of AD, AR and asthma were obtained. The children underwent a clinical investigation, including skin prick tests and peak expiratory flow measurements, where the presence of AD, AR and asthma were evaluated. The associations of these diseases to the s‐ECP values were examined in bivariate statistical analysis. Results No statistical significant associations were detected in bivariate analysis between s‐ECP and AD, AR or asthma: the mean s‐ECP in children without self‐reported AD/AR/asthma was 4.6 µg/L [95% confidence interval (CI) 4.0–5.2]. The mean s‐ECP in children with self‐reported AD or AR or asthma was 5.2 µg/L (95% CI 4.1–6.2), 4.6 µg/L (95% CI 3.5–5.7) and 6.4 µg/L (95% CI 4.4–8.3), respectively. The highest mean s‐ECP level was measured in children with clinically diagnosed asthma; 7.1 µg/L (95% CI 4.0–10.3). Above the 75‐percentile level of s‐ECP, only 17.2% of the children had a history of asthma. Conclusions In this unselected children population, the occurrence of AD or AR was not reflected by an increase in the s‐ECP level. The s‐ECP was increased in children with asthma, but was not statistically significant. Furthermore, the majority of children with high s‐ECP values were not asthmatics. We conclude that the associations between s‐ECP and allergic diseases are weak in an unselected population of children.     

Characteristics of extrinsic vs. intrinsic atopic dermatitis in infancy: correlations with laboratory variables

BACKGROUND: Atopic dermatitis (AD) has been divided into the extrinsic type (ADe) and the intrinsic type (ADi) according to the serum IgE levels and the presence or absence of allergen-specific IgE. Although previous studies have demonstrated differences in the various immunological parameters, the characteristics of AD in infancy have rarely been reported. OBJECTIVES: Our study was performed to analyse the correlations between the laboratory parameters of infantile ADe and ADi. METHODS: We recruited 237 infants with AD and checked the SCORAD index, the number of peripheral blood eosinophils, the serum eosinophil cationic protein (ECP) levels, the total serum IgE levels and the specific serum IgE levels in all the patients. We also checked the serum interleukin (IL)-4 and IL-5 levels in 20 patients with ADe and in 20 with ADi. RESULTS: This study showed many peculiar characteristics of infantile AD. In infancy, ADi was more prevalent than ADe. The eosinophil count, the ECP level and the SCORAD in ADi were lower than in ADe. Furthermore, a group of patients without characteristics of ADi or ADe could be identified. We tentatively classify this group as indeterminate type (ADind) and propose it as a separate entity. The clinical severity was well correlated with the eosinophil count and the serum ECP levels in ADe and ADi. Therefore these two parameters could be used as clinical severity markers in infancy. Infants are more allergic to food, and the variety of specific allergenic responses was connected with clinical severity. A higher eosinophil count, a higher ECP level and a higher detection rate of IL-5 in the peripheral blood of infants with ADe means that eosinophils have a more prominent role in ADe than in ADi. CONCLUSIONS: Infantile AD has many distinctive features in its laboratory variables as compared with AD in other age groups. Clinicians should recognize these facts when they deal with infants with AD, and further studies are warranted on the natural course of infantile AD.