ABSTRACT
Chitinase-3-like-1 (CHI3L1) is known to induce inflammation in the progression of allergic diseases. Previous our studies revealed that 2-({3-[2-(1-cyclohexen-1-yl)ethyl]-6,7-dimethoxy-4-oxo-3,4-dihydro-2-quinazolinyl}sulfanyl)-N-(4-ethylphenyl)butanamide (K284-6111; K284), the CHI3L1 inhibiting compound, has the anti-inflammatory effect on neuroinflammation. In this study, we investigated that K284 treatment could inhibit the development of atopic dermatitis (AD). To identify the effect of K284, we used phthalic anhydride (5% PA)-induced AD animal model and in vitro reconstructed human skin model. We analyzed the expression of AD-related cytokine mediators and NF-κB signaling by Western blotting, ELISA and quantitative real-time PCR. Histological analysis showed that K284 treatment suppressed PA-induced epidermal thickening and infiltration of mast cells.K284 treatment also reduced PA-induced release of inflammatory cytokines. In addition, K284 treatment inhibited the expression of NF-κB activity in PA-treated skin tissues and TNF-α and IFN-γ-treated HaCaT cells. Protein-association network analysis indicated that CHI3L1 is associated with lactoferrin (LTF). LTF was elevated in PA-treated skin tissues and TNF-α and IFN-γ-induced HaCaT cells. However, this expression was reduced by K284 treatment. Knockdown of LTF decreased the expression of inflammatory cytokines in TNF-α and IFN-γ-induced HaCaT cells. Moreover, anti-LTF antibody treatment alleviated AD development in PA-induced AD model. Our data demonstrate that CHI3L1 targeting K284 reduces AD-like skin inflammation and K284 could be a promising therapeutic agent for AD by inhibition of LTF expression.
ABSTRACT
Chitinase-3-like-1 (CHI3L1) is known to induce inflammation in the progression of allergic diseases. Previous our studies revealed that 2-({3-[2-(1-cyclohexen-1-yl)ethyl]-6,7-dimethoxy-4-oxo-3,4-dihydro-2-quinazolinyl}sulfanyl)-N-(4-ethylphenyl)butanamide (K284-6111; K284), the CHI3L1 inhibiting compound, has the anti-inflammatory effect on neuroinflammation. In this study, we investigated that K284 treatment could inhibit the development of atopic dermatitis (AD). To identify the effect of K284, we used phthalic anhydride (5% PA)-induced AD animal model and in vitro reconstructed human skin model. We analyzed the expression of AD-related cytokine mediators and NF-κB signaling by Western blotting, ELISA and quantitative real-time PCR. Histological analysis showed that K284 treatment suppressed PA-induced epidermal thickening and infiltration of mast cells.K284 treatment also reduced PA-induced release of inflammatory cytokines. In addition, K284 treatment inhibited the expression of NF-κB activity in PA-treated skin tissues and TNF-α and IFN-γ-treated HaCaT cells. Protein-association network analysis indicated that CHI3L1 is associated with lactoferrin (LTF). LTF was elevated in PA-treated skin tissues and TNF-α and IFN-γ-induced HaCaT cells. However, this expression was reduced by K284 treatment. Knockdown of LTF decreased the expression of inflammatory cytokines in TNF-α and IFN-γ-induced HaCaT cells. Moreover, anti-LTF antibody treatment alleviated AD development in PA-induced AD model. Our data demonstrate that CHI3L1 targeting K284 reduces AD-like skin inflammation and K284 could be a promising therapeutic agent for AD by inhibition of LTF expression.
ABSTRACT
PURPOSE: In our previous study, we demonstrated that both titrated extract of Centella asiatica (TECA) and astaxanthin (AST) have anti-inflammatory effects in a 5% phthalic anhydride (PA) mouse model of atopic dermatitis (AD). The increasing prevalence of AD demands new therapeutic approaches for treating the disease. We investigated the therapeutic efficacy of the ointment form of TECA, AST and a TECA + AST combination in a mouse model of AD to see whether a combination of the reduced doses of 2 compounds could have a synergistic effect. METHODS: An AD-like lesion was induced by the topical application of 5% PA to the dorsal ear and back skin of an Hos:HR-1 mouse. After AD induction, TECA (0.5%), AST (0.5%) and the TECA (0.25%) + AST (0.25%) combination ointment (20 μg/cm2) were spread on the dorsum of the ear or back skin 3 times a week for 4 weeks. We evaluated dermatitis severity, histopathological changes and changes in protein expression by Western blotting for inducible nitric oxide synthase (iNOS), cyclocxygenase (COX)-2, and nuclear factor (NF)-κB activity. We also measured the concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and immunoglobulin E (IgE) in the blood of AD mice by enzyme-linked immunosorbent assay (ELISA). RESULTS: PA-induced skin morphological changes and ear thickness were significantly reduced by TECA, AST and TECA + AST treatments, but these inhibiting effects were more pronounced in the TECA + AST treatment. TECA, AST and the TECA+AST reatments inhibited the expression of iNOS and COX-2; NF-κB activity; and the release of TNF-α, IL-6 and IgE. However, the TECA+AST treatment showed additive or synergistic effects on AD. CONCLUSIONS: Our results demonstrate that the combination of TECA and AST could be a promising therapeutic agent for AD by inhibiting NF-κB signaling.