Identification of differentially expressed microRNAs in the skin of experimentally sensitized naturally affected atopic beagles by next-generation sequencing.

Canine atopic dermatitis (AD) is a very common inflammatory skin disease, but limited data are available on the genetic characterization (somatic mutations, microarrays, and genome-wide association study (GWAS)) of skin lesions in affected dogs. microRNAs are good biomarkers in inflammatory and neoplastic diseases in people. The aim of this study was to evaluate microRNA expression in the skin of atopic beagles, before and after exposure to Dermatophagoides farinae. Four atopic and four unrelated age-matched healthy beagle dogs were enrolled. Total RNA was extracted from flash-frozen skin biopsies of healthy and atopic dogs. For the atopic dogs, skin biopsies were taken from non-lesional (day 0) and lesional skin (day 28 of weekly environmental challenge with Dermatophagoides farinae). Small RNA libraries were constructed and sequenced. The microRNA sequences were aligned to CanFam3.1 genome. Differential expressed microRNAs were selected on the basis of fold-change and statistical significance (fold-change ≥ 1.5 and p ≤ 0.05 as thresholds. A total of 277 microRNAs were sequenced. One hundred and twenty-one differentially regulated microRNAs were identified between non-lesional and healthy skin. Among these, two were increased amount and 119 were decreased amount. A total of 45 differentially regulated microRNAs between lesional and healthy skin were identified, 44 were decreased amount and one was increased amount. Finally, only two increased amount microRNAs were present in lesional skin when compared with that of non-lesional skin. This is the first study in which dysregulation of microRNAs has been associated with lesional and non-lesional canine AD. Larger studies are needed to understand the role of microRNA in canine AD.

Allergy immunotherapy restores airway epithelial barrier dysfunction through suppressing IL-25 -induced endoplasmic reticulum stress in asthma.

Constant exposure to allergen triggers destructive type 2 cell-mediated inflammation. The effect of allergen specific immunotherapy (SIT) in maintaining airway epithelial barrier function in asthma remains unknown. In the current study, we showed that SIT maintained airway epithelial homeostasis in mice exposed to dermatophagoides farinae (Der f), which induced increased expression of IL-25, endoplasmic reticulum (ER) stress and airway epithelial apoptosis. Meanwhile, SIT treatment ameliorated airway inflammatory infiltration and hyper-responsiveness in allergic mice. SIT treatment restored the airway epithelial integrity, attenuated Der f -induced airway epithelial ER stress and epithelial apoptosis. We also found that 4-PBA, an inhibitor of ER stress, suppressed airway epithelial ER stress and apoptosis in vitro. The pathological changes were partially induced by IL-25-induced ER stress, epithelial tight junction damage, and cell apoptosis in airways following allergen exposure. Furthermore, IL-25 induced ER stress in airway epithelial cells in vitro. The IL-25-induced airway epithelial apoptosis dependent on PERK activity was inhibited by 4-PBA. Taken together, we demonstrate that SIT is effective in allergic asthma and dependent on its depressive effect on the expression of IL-25, epithelial integrity damage, and epithelial ER stress.

Clinical evaluation for sublingual immunotherapy with Dermatophagoides farinae drops in adult patients with allergic asthma.

PURPOSE: The efficacy and safety of sublingual immunotherapy (SLIT) in house dust mite-induced allergic asthma (AA) have yet to be firmly established, especially in adult patients. Our objective is to evaluate the efficacy of SLIT with Dermatophagoides farinae drops in adult patients with AA. METHODS: One hundred and thirty-four adult patient data with house dust mite (HDM)-induced AA who had been treated for 2 years were collected. These patient data that we collected were divided into the SLIT group (n = 85) and control group (n = 49). All patients were treated with low to moderate dose of inhaled glucocorticoid and long-acting ß2 agonists. Patients in the SLIT group were further treated with D. farinae drops. Clinical scores including the total asthma symptom score (TASS), total asthma medicine score (TAMS), asthma control test (ACT), and peak flow percentage (PEF%) were assessed before treatment and at yearly visits. The presence of adverse events (AEs) were recorded once a month. RESULTS: Before treatment, the PEF% in the SLIT group was significantly lower than that in the control group (p < 0.05). After 2 years, both treatments were effective in the clinical scores when compared with baseline values (all p < 0.001). Meanwhile, the SLIT group showed significantly lower TASS and TAMS (all p < 0.001) and higher ACT (p < 0.001) and PEF% (p < 0.05) when compared with the control group. No severe systemic AEs were reported. CONCLUSIONS: SLIT with D. farinae drops plus pharmacotherapy is more effective than routine drug treatment in adult patients with AA.

Chlorella vulgaris Attenuates Dermatophagoides Farinae-Induced Atopic Dermatitis-Like Symptoms in NC/Nga Mice.

Atopic dermatitis (AD) is a chronic and inflammatory skin disease that can place a significant burden on quality of life for patients. AD most frequently appears under the age of six and although its prevalence is increasing worldwide, therapeutic treatment options are limited. Chlorella vulgaris (CV) is a species of the freshwater green algae genus chlorella, and has been reported to modulate allergy-inducible factors when ingested. Here, we examined the effect of CV supplementation on AD-like symptoms in NC/Nga mice. CV was orally administrated for six weeks while AD-like symptoms were induced via topical application of Dermatophagoides farinae extract (DFE). CV treatment reduced dermatitis scores, epidermal thickness, and skin hydration. Histological analysis also revealed that CV treatment reduced DFE-induced eosinophil and mast cell infiltration into the skin, while analysis of serum chemokine levels indicated that CV treatment downregulated thymus- and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC) levels. In addition, CV treatment downregulated mRNA expression levels of IL-4 and IFN-γ. Taken together, these results suggest that CV extract may have potential as a nutraceutical ingredient for the prevention of AD.

Modulation of HMGB1 translocation and RAGE/NFκB cascade by quercetin treatment mitigates atopic dermatitis in NC/Nga transgenic mice.

Quercetin, glycosylated form of flavonoid compound, has potent antioxidant and anti-inflammatory properties. In this study, we have investigated the effects of quercetin on skin lesion, high-mobility group box (HMGB)1 cascade signalling and inflammation in atopic dermatitis (AD) mouse model. AD-like lesion was induced by the application of house dust mite extract to the dorsal skin of NC/Nga transgenic mouse. After AD induction, quercetin (50 mg/kg, p.o) was administered daily for 2 weeks. We evaluated dermatitis severity, histopathological changes and changes in protein expression by Western blotting for HMGB1, receptor for advanced glycation end products (RAGE), toll-like receptor (TLR)4, nuclear factor (NF)κB, nuclear factor erythroid-2-related factor (Nrf)2, kelch-like ECH-associated protein (Keap)1, extracellular signal-regulated kinase (ERK)1/2, cyclooxygenase (COX)2, tumor necrosis factor (TNF)α, interleukin (IL)-1ß, IL-2Rα and other inflammatory markers in the skin of AD mice. In addition, serum levels of T helper (Th) cytokines (interferon (IFN)γ, IL-4) were measured by enzyme-linked immunosorbent assay. Quercetin treatment attenuated the development of AD-like skin lesions. Histological analysis showed that quercetin inhibited hyperkeratosis, parakeratosis, acanthosis, mast cells and infiltration of inflammatory cells. Furthermore, quercetin treatment downregulated cytoplasmic HMGB1, RAGE, nuclear p-NFκB, p-ERK1/2, COX2, TNFα, IL-1ß, IL-2Rα, IFNγ and IL-4 and upregulated nuclear Nrf2. Our data demonstrated that the HMGB1/RAGE/NFκB signalling might play an important role in skin inflammation, and quercetin treatment could be a promising agent for AD by modulating the HMGB1/RAGE/NFκB signalling and induction of Nrf2 protein.

DAMP molecules S100A9 and S100A8 activated by IL-17A and house-dust mites are increased in atopic dermatitis.

S100A9 and S100A8 are called damage-associated molecular pattern (DAMP) molecules because of their pro-inflammatory properties. Few studies have evaluated S100A9 and S100A8 function as DAMP molecules in atopic dermatitis (AD). We investigated how house-dust mites affect S100A9 and S100A8 expression in Th2 cytokine- and Th17 cytokine-treated keratinocytes, and how secretion of these molecules affects keratinocyte-derived cytokines. Finally, we evaluated expression of these DAMP molecules in AD patients. S100A9 expression and S100A8 expression were strongly induced in IL-17A- and Dermatophagoides (D.) farinae-treated keratinocytes, respectively. Furthermore, co-treatment with D. farinae and IL-17A strongly increased expression of S100A9 and S100A8 compared with D. farinae-Th2 cytokine co-treatment. The IL-33 mRNA level increased in a dose-dependent manner in S100A9-treated keratinocytes, but TSLP expression did not change. S100A8/A9 levels were also higher in the lesional skin and serum of AD patients, and correlated with disease severity. Taken together, S100A9 and S100A8 may be involved in inducing DAMP-mediated inflammation in AD triggered by IL-17A and house-dust mites.

Mite hypersensitivity in patients with rhinitis and rhinosinusitis living in a tropical environment

PURPOSE: Rhinitis and rhinosinusitis are major concerns in public health. Mites are important aetiological agents in the tropics. The present study investigated the in vivo response to mite allergens in patients with rhinitis and rhinosinusitis. METHODS: All patients with presumptive nasal allergy were included. Skin tests were done with inhalants and mite extracts. Patients were classified as allergic or non-allergic according to skin tests and history. RESULTS: Out of 229 patients, 175 (76.4%) showed positive skin tests. Allergic patients showed positivity to mites in 97.1% of cases, 51.4% to dog dander; 40.5% to cat dander; 36.5% to German cockroach; 22.8% to moulds; and 21.1% to grass pollens. Dermatophagoides farinae induced responses in 90.8% of patients, D. pteronyssinus in 90.1%, Blomia tropicalis in 74.8%, Glycyphagus domesticus in 62.2%, Chortoglyphus arcuatus in 58.2%, Acarus siro in 46.2%, Lepidoglyphus destructor in 35.4%, and Tyrophagus putrescentiae in 35.0%. Higher correlations were found between skin test diameters induced by mites from the same family. CONCLUSIONS: Sensitisation to inhalant allergens is present in 76% of allergy clinics' patients with rhinitis or rhinosinusitis. Our results confirm previous observations showing that mites constitute the most important cause of respiratory allergy in tropical settings and suggest that mite allergen cross-reactivity is responsible for the positivity of skin tests to mites not present in the patient's environment since the species Glycyphagus, Chortoglyphus, Acarus, Lepidoglyphus and Tyrophagus have not been found in Caracas house dust

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[[Expression of house dust mite allergens Der f1 and Der f2 in Nicotiana benthamiana leaves].

The class E immunoglobulins (IgE) is known to recognize conformational epitopes and therefore the native conformation of recombinant allergens is essential for their using in test-systems. Recombinant Dermatophagoides farinae house dust mite (HDM) allergens Der f1 and Der f2 were expressed in bacteria Escherichia coli and Nicotiana benthamiana plants. It has been shown that IgE in sera from children allergic to HDM recognizes Der f2 expressed both in E. coli and N. benthamiana. Mature form of Der f1 expressed in E. coli does not interact with IgE while the protein purified from N. benthamiana is able to recognize IgE as a native allergen.

The fruits of Cudrania tricuspidata suppress development of atopic dermatitis in NC/Nga mice.

The fruits of Cudrania tricuspidata are a medicinal herb in Korea, known for its antiatherosclerotic and antiinflammatory effects. Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by the influx of lymphocytes into the dermis. Using an animal model of AD, we assessed whether C. tricuspidata suppresses the development of AD-like skin lesions. Cudrania tricuspidata was administered orally to NC/Nga mice with Dermatophagoides-farinae-induced AD-like lesions for 49 days. The effects of C. tricuspidata were assessed by measuring clinical symptoms, swelling of the skin on the back and ears, and plasma concentrations of mTARC (mouse thymus and activation regulated chemokine), histamine and immunoglobulin E (IgE). We found that C. tricuspidata (60 mg/kg/day) inhibited the development of AD-like skin lesions, reduced skin dermatitis scores and inhibited the histological changes induced by repeated application of D. farinae. In addition, C. tricuspidata inhibited the increases in plasma concentrations of mTARC, histamine and IgE induced by D. farinae. These findings indicate that C. tricuspidata inhibits the development of AD-like skin lesions induced by repeated applications of D. farinae in sensitized NC/Nga by suppressing plasma concentrations of mTARC, histamine and IgE.

Identification of immunoglobulin E binding components of the two-spotted spider mite Tetranychus urticae: allergenic relationships with the citrus red mite and house-dust mite.

The two-spotted mite (TSM) is commonly found on fruit trees, herbaceous plants, and greenhouse flowers. However, a recent investigation indicated that the sensitization rate to TSM was as high as that of house-dust mites (HDMs) in nonfarmers as well as in farmers working in orchards in this country. The aim of this study was to identify immunoglobulin E (IgE)-binding components within TSM and to evaluate the allergenic relationship with the citrus red mite (CRM) and HDM. Sera were collected from eight patients who were not farmers and who had asthma with high serum-specific IgE to the TSM and from unexposed controls showing negative responses to the TSM on skin-prick test. Twelve percent sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis were applied. To evaluate allergenic relationships with HDMs and CRMs, two kinds of sera pools were used: one (A) showing positive responses to both TSMs and HDMs and the other (B) showing an isolated positive response to TSMs. ELISA inhibition tests using A and B pooled sera were conducted. The TSM-ELISA inhibition test using sera A showed significant inhibition with addition of TSMs and CRMs, partial inhibition with HDMs, and minimal inhibition with other inhalant allergens. The ELISA inhibition test using sera B showed significant inhibition with TSMs and CRMs and minimal inhibition was noted with HDMs as well as other inhalant allergens. Immunoblot analysis using individual sera showed seven IgE-binding components (75, 56, 47, 41, 37, 28, and 14 kDa) and two (75 and 14 kDa) of them were bound to IgE in > 50% of the sera tested. Seven IgE-binding components were identified within the TSM extract and two (75 and 14 kDa) could be considered major allergens. It is suggested that the TSM contains species-specific allergen in addition to shared allergens with CRMs and HDMs.