Keratinocytes-Derived Reactive Oxygen Species Play an Active Role to Induce Type 2 Inflammation of the Skin: A Pathogenic Role of Reactive Oxygen Species at the Early Phase of Atopic Dermatitis

Background@#Atopic dermatitis (AD) is characterized by chronic, relapsing skin inflammation (eczema) with itchy sensation. Keratinocytes, which are located at the outermost part of our body, are supposed to play important roles at the early phase of type 2 inflammation including AD pathogenesis. @*Objective@#The purpose of this study was to evaluate whether keratinocytes-derived reactive oxygen species (ROS) could be produced by the allergens or non-allergens, and the keratinocytes-derived ROS could modulate a set of biomarkers for type 2 inflammation of the skin. @*Methods@#Normal human epidermal keratinocytes (NHEKs) were treated with an allergen of house dust mites (HDM) or a non-allergen of compound 48/80 (C48/80). Then, biomarkers for type 2 inflammation of the skin including those for neurogenic inflammation were checked by reverse transcriptase-polymerase chain reaction and western immunoblot experiments. @*Results@#HDM or C48/80 was found to upregulate expression levels of our tested biomarkers, including type 2 T helper-driving pathway (KLK5, PAR2, and NF κ B), epithelial-cell-derived cytokines (thymic stromal lymphopoietin, interleukin [IL]-25, IL-33), and neurogenic inflammation (NGF, CGRP). The HDMor C-48/80-induced expression levels of the biomarkers could be blocked by an antioxidant treatment with 5 mM N-acetyl-cysteine. In contrast, pro-oxidant treatment with 1 mM H2O2 could upregulate expression levels of the tested biomarkers in NHEKs. @*Conclusion@#Our results reveal that keratinocytes-derived ROS, irrespective to their origins from allergens or non-allergens, have a potential to induce type 2 inflammation of AD skin.

Ethanol Extract of Peanut Sprout Exhibits a Potent Anti-Inflammatory Activity in Both an Oxazolone-Induced Contact Dermatitis Mouse Model and Compound 48/80-Treated HaCaT Cells

BACKGROUND: We developed an ethanol extract of peanut sprouts (EPS), a peanut sprout-derived natural product, which contains a high level of trans-resveratrol (176.75 microg/ml) and was shown to have potent antioxidant activity. OBJECTIVE: We evaluated the potential anti-inflammatory activity of EPS by measuring its antioxidant potential in skin. METHODS: The anti-inflammatory activity of EPS was tested using two models of skin inflammation: oxazolone (OX)-induced contact dermatitis in mice and compound 48/80-treated HaCaT cells. As biomarkers of skin inflammation, cyclooxygenase-2 (COX-2) and nerve growth factor (NGF) levels were measured. RESULTS: OX-induced contact dermatitis was suppressed markedly in mice that were treated with an ointment containing 5% EPS as evidenced by a decrease in the extent of scaling and thickening (p<0.05) and supported by a histological study. COX-2 (messenger RNA [mRNA] and protein) and NGF (mRNA) levels, which were upregulated in the skin of OX-treated mice, were suppressed markedly in the skin of OX+EPS-treated mice. Consistent with this, compound 48/80-induced expression of COX-2 (mRNA and protein) and NGF (mRNA) in HaCaT cells were suppressed by EPS treatment in a dose-dependent manner. As an inhibitor of NF-kappaB, IkappaB protein levels were dose-dependently upregulated by EPS. Fluorescence-activated cell sorting (FACS) analysis revealed that EPS scavenged compound 48/80-induced reactive oxygen species (ROS) in HaCaT cells. CONCLUSION: EPS exerts a potent anti-inflammatory activity via its anti-oxidant activity in both mouse skin and compound 48/80-treated HaCaT cells in vitro. Compound 48/80-treated HaCaT cells are a useful new in vitro model of skin inflammation.

Effects of 630 nm Light-Emitting Diode Irradiation on Caveolin-1 and Procollagen I and III Expression in Human Dermal Fibroblasts / 대한피부과학회지

BACKGROUND: Recent studies indicate that light-emitting diodes (LED) may represent a novel and effective anti-aging light source for the skin. Among many candidate molecules known to control collagens, caveolin-1 (Cav-1) is known to play an inhibitory role in cutaneous collagen metabolism. OBJECTIVE: This study aimed to evaluate the effects of LED irradiation on the expression levels of Cav-1 and procollagens (proCOLs) in human dermal fibroblasts (HDFs). METHODS: Cultured HDFs were irradiated with 630 nm LED at different doses, and the mRNA and protein expression levels of Cav-1 and proCOLs I/III were analyzed. RESULTS: In LED-irradiated HDFs, mRNA and protein levels of Cav-1 were found to be down-regulated, whereas those of proCOLs I/III were up-regulated in a dose-dependent manner. A negative correlation between Cav-1 and proCOLs was verified in Cav-1 siRNA transfected HDFs. LED was moreover found to result in up-regulation of transforming growth factor (TGF)-beta1 and its receptors (TbetaRI, TbetaRII), SMAD1, and SMAD2 mRNA levels, indicating that LED may activate the TGF-1/TbetaR/SMAD pathway in HDFs. CONCLUSION: The anti-aging effects of 630 nm LED on human skin are likely mediated by up-regulation of proCOLs I/III and inhibition of Cav-1 expression levels in HDFs.