Innate Type 2 Response to Aspergillus fumigatus in a Murine Model of Atopic Dermatitis-like Skin Inflammation

Oyster hydrolysate ameliorates UVB-induced skin dehydration and barrier dysfunction

Ultraviolet (UV) exposure triggers skin aging primarily by disrupting skin barrier function, resulting in dry skin and wrinkle formation. Oyster hydrolysate (OH), as a functional food, has been reported for anti-cancer, anti-oxidant and anti-apoptotic effects. This study investigated the underlying mechanism of OH effect on UVB-induced skin aging in SKH1 hairless mice. Mice were exposed to UVB three times per week while they were fed with a normal diet or diet containing OH for 10 weeks. Additionally, a randomized, double-blind, and placebo-controlled clinical trial was performed to investigate the OH effect on human skin moisturizing to evaluate its efficacy and safety. UVB exposure increased parameters of skin aging; dehydration, transepidermal water loss, and macroscopic dorsal skin lesions. OH significantly reduced these features of skin aging. Histological analysis demonstrated that OH decreased skin epidermal and dermal thickness and collagen degradation induced by UVB. OH significantly reduced ROS production, suppressed macrophage activation and neutrophil infiltration, and downregulated pro-inflammatory cytokine production. OH improved skin barrier function by increasing the expression of filaggrin, aquaporin-3, and hyaluronic acid synthesis enzymes and promoting recovery from skin damage. Importantly, the results from a human clinical trial demonstrated that OH improved skin moisturization and integrity with no side effects. Taken together, OH supplementation ameliorates skin damage via anti-oxidant and anti-inflammatory properties and enhances skin hydration and barrier function. OH has a therapeutic potential for skin photoaging.

Type 2 Innate Lymphoid Cells and Skin Fibrosis in a Murine Model of Atopic Dermatitis-Like Skin Inflammation

BACKGROUND

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease. Although murine studies have demonstrated that type 2 innate lymphoid cells (ILCs) mediate type 2 skin inflammation, their role in skin fibrosis in AD remains unclear. This study investigated whether type 2 ILCs are involved in skin fibrosis using an AD-like murine model.

METHODS

C57BL/6 mice were treated epicutaneously with Aspergillus fumigatus (Af) for 5 consecutive days per week for 5 weeks to induce skin fibrosis. Mature lymphocyte deficient Rag1-/- mice were also used to investigate the role of type 2 ILCs in skin fibrosis.

RESULTS

The clinical score and transepidermal water loss (TEWL) were significantly higher in the AD group than in the control group. The AD group also showed significantly increased epidermal and dermal thicknesses and significantly higher numbers of eosinophils, neutrophils, mast cells, and lymphocytes in the lesional skin than the control group. The lesional skin of the AD group showed increased stain of collagen and significantly higher levels of collagen than the control group (10.4 ± 2.2 µg/mg vs. 1.6 ± 0.1 µg/mg, P < 0.05). The AD group showed significantly higher populations of type 2 ILCs in the lesional skin compared to the control group (0.08 ± 0.01% vs. 0.03 ± 0.01%, P < 0.05). These findings were also similar with the AD group of Rag1-/- mice compared to their control group. Depletion of type 2 ILCs with anti-CD90.2 monoclonal antibodies significantly improved clinical symptom score, TEWL, and infiltration of inflammatory cells, and significantly decreased levels of collagen were observed in the AD group of Rag1-/- mice (1.6 ± 0.0 μg/mg vs. 4.5 ± 0.3 μg/mg, P < 0.001).

CONCLUSION

In the Af-induced AD-like murine model, type 2 ILCs were elevated, with increased levels of collagen. Additionally, removal of type 2 ILCs resulted in decreased collagen levels and improved AD-like pathological findings. These findings suggest that type 2 ILCs play a role in the mechanism of skin fibrosis in AD.

Homobifunctional imidoester-modified zinc nano-spindle attenuated hyphae growth of Aspergillus against hypersensitivity responses

Fungi cause various forms of invasive fungal disease (IFD), and fungal sensitization can contribute to the development of asthma, asthma severity, and other hypersensitivity diseases, such as atopic dermatitis (AD). In this study, we introduce a facile and controllable approach, using homobifunctional imidoester-modified zinc nano-spindle (HINS), for attenuating hyphae growth of fungi and reducing the hypersensitivity response complications in fungi-infected mice. To extend the study of the specificity and immune mechanisms, we used HINS-cultured Aspergillus extract (HI-AsE) and common agar-cultured Aspergillus extract (Con-AsE) as the refined mouse models. HINS composites within the safe concentration range inhibited the hyphae growth of fungi but also reduce the number of fungal pathogens. Through the evaluation of lung and skin tissues from the mice, asthma pathogenesis (lung) and the hypersensitivity response (skin) to invasive aspergillosis were least severe in HI-AsE-infected mice. Therefore, HINS composites attenuate asthma and the hypersensitivity response to invasive aspergillosis.

Personal Exposure to Total VOC Is Associated With Symptoms of Atopic Dermatitis in Schoolchildren

BACKGROUND

The urinary levels of volatile organic compound (VOC) metabolites provide individual exposure levels compared to data obtained by measuring these compounds in ambient air. We aimed to investigate the association between personal urinary concentrations of VOC metabolites and symptoms of atopic dermatitis in schoolchildren.

METHODS

Nine urinary VOC metabolites were analyzed from urine samples of 149 children. Diagnosis of atopic dermatitis was determined using standardized questionnaires. Pediatricians visited the schools and rated the severity of symptoms using the SCORing Atopic Dermatitis (SCORAD) in all children.

RESULTS

Forty-five children (30.2%) had atopic dermatitis based on the International Study of Asthma and Allergies in Childhood (ISAAC) results and 35 children (23.8%) had symptoms of atopic dermatitis with positive SCORAD index values (defined as SCORAD ≥ 5). Children with benzylmercapturic acid detected in personal urines were associated with presence of atopic dermatitis and positive SCORAD index values. Children in the highest quartile of mandelic acid concentration were associated with presence of atopic dermatitis and positive SCORAD results.

CONCLUSION

Personal exposure to VOCs, as indicated by urinary levels of VOC metabolites, was associated with presence of atopic dermatitis and the SCORAD index value.