The Antiaging Activity of Ergothioneine in UVA-Irradiated Human Dermal Fibroblasts via the Inhibition of the AP-1 Pathway and the Activation of Nrf2-Mediated Antioxidant Genes

Figure 6

EGT pretreatment facilitated the nuclear translocation of Nrf2 to induce downstream antioxidant protein expression in UVA-irradiated HSF cells. (a) Effect of EGT concentration on total Nrf2, HO-1, γ-GCLC, and NQO-1 expression in UVA-irradiated HSF cells. HSF cells were pretreated with EGT (0.125-0.5 μM) for 24 h followed by irradiated without or with 3 J/cm² UVA. Western blot results showing that EGT dose-dependently upregulated total Nrf2, HO-1, γ-GCLC, and NQO-1 levels. β-Actin as an internal control using densitometry. (b) Immunofluorescence staining of subcellular localization of Nrf2 in EGT-treated and UVA-irradiated cells. HSF cells were pretreated with 0.5 μM EGT for 24 h and then irradiated without or with 3 J/cm² UVA. The percentage of fluorescence cell intensity of each experimental condition was quantified using Olympus Soft Imaging Solutions. (c) Effect of EGT on nuclear translocation of endogenous Nrf2 in UVA-irradiated cells. HSF cells were pretreated with 0.5 μM EGT for 24 h and then irradiated without or with 3 J/cm² UVA. Western blot results showing the effect of EGT on the protein expressions of nuclear as well as the cytosolic Nrf2 levels. Changes in protein expressions were analyzed using densitometry against histone and β-actin as the internal controls. Changes in protein expressions were analyzed against β-actin as an internal control using densitometry. Data were presented as of three or more assays. and compared with untreated control cells and ^## compared with UVA-irradiated cells.

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