Protective effects of novel derivatives of vitamin D3 and lumisterol against UVB-induced damage in human keratinocytes involve activation of Nrf2 and P53 defense mechanisms

Abstract

We tested whether novel CYP11A1-derived vitamin D 3-and lumisterol-hydroxyderivatives, including 1,25(OH) 2 D 3 , 20(OH)D 3 , 1,20(OH) 2 D 3 , 20,23(OH) 2 D 3 , 1,20,23(OH) 3 D 3 , lumisterol, 20(OH)L 3 , 22(OH)L 3 , 20,22(OH) 2 L 3 , and 24(OH)L 3 , can protect against UVB-induced damage in human epidermal keratinocytes. Cells were treated with above compounds for 24 h, then subjected to UVB irradiation at UVB doses of 25, 50, 75, or 200 mJ/cm 2 , and then examined for oxidant formation, proliferation, DNA damage, and the expression of genes at the mRNA and protein levels. Oxidant formation and proliferation were determined by the DCFA-DA and MTS assays, respectively. DNA damage was assessed using the comet assay. Expression of antioxidative genes was evaluated by real-time RT-PCR analysis. Nuclear expression of CPD, phospho-p53, and Nrf2 as well as its target proteins including HO-1, CAT, and MnSOD, were assayed by immunofluorescence and western blotting. Treatment of cells with the above compounds at concentrations of 1 or 100 nM showed a dose-dependent reduction in oxidant formation. At 100 nM they inhibited the proliferation of cultured keratinocytes. When keratinocytes were irradiated with 50-200 mJ/cm 2 of UVB they also protected against DNA damage, and/or induced DNA repair by enhancing the repair of 6-4PP and attenuating CPD levels and the tail moment of comets. Treatment with test compounds increased expression of Nrf2-target genes involved in the antioxidant response including GR, HO-1, CAT, SOD1, and SOD2, with increased protein expression for HO-1, CAT, and MnSOD. The treatment also stimulated the phosphorylation of p53 at Ser-15, increased its concentration in the nucleus and enhanced Nrf2 translocation into the nucleus. In conclusion, pretreatment of keratinocytes with 1,25(OH) 2 D 3 or CYP11A1-derived vitamin D 3-or lumisterol hydroxy-derivatives, protected them against UVB-induced damage via activation of the Nrf2-dependent antioxidant response and p53-phosphorylation, as well as by the induction of the DNA repair system. Thus, the new vitamin D 3 and lumisterol hydroxy-derivatives represent promising anti-photodamaging agents.

Participation of keratinocyte‐ and fibroblast‐derived factors in melanocyte homeostasis, the response to UV, and pigmentary disorders

“…In human keratinocytes, the expression of VDR is important for efficient NER, as it promotes the dissociation of XPC from DNA damage sites to allow subsequent enzymes to resume the repair of DNA photoproducts (Wong & Oh, 2021). Recently, it was reported that D3 has potent antioxidant effects on UV‐irradiated keratinocytes by activating Nrf2 (Chaiprasongsuk et al., 2019). Additionally, D3 results in increased p53 levels and its transactivation in keratinocytes and melanocytes irradiated with UV (Chaiprasongsuk et al., 2019; Dixon et al., 2005).…”

“…Recently, it was reported that D3 has potent antioxidant effects on UV‐irradiated keratinocytes by activating Nrf2 (Chaiprasongsuk et al., 2019). Additionally, D3 results in increased p53 levels and its transactivation in keratinocytes and melanocytes irradiated with UV (Chaiprasongsuk et al., 2019; Dixon et al., 2005). The antioxidant effect of D3 is supported by the findings that its analog tacalcitol reduces hydrogen peroxide‐induced ROS and oxidative damage in melanocytes (Li et al., 2011), and enhances transactivation of Nrf2 in hydrogen peroxide‐induced melanocytes (Tang et al., 2018).…”

Antiphotoaging Potential of Extracts of Yin‐Tonic Herbal Medicine in Skin Cell and Human Skin Equivalent

“…Second, this study is limited by the lack of information on the natural compounds that exert photoprotective effect. Plant extracts, natural compounds, or metabolites such as melatonin [ 33 ] and vitamin D compounds [ 34 ] have been considered as one of the most promising sources to prevent or ameliorate the effects of UVB. Some yin-tonic herbal medicines possess antioxidant properties, having rich antioxidants such as phenolic compounds, which contribute to the yin-tonic or antioxidative activity [ 35 , 36 ] as well as anti-inflammatory properties [ 35 ], implying that yin-yang theory is somewhat equivalent to the modern theory of antioxidant-oxidant balance.…”

Increased Histone Acetylation and Decreased Expression of Specific Histone Deacetylases in Ultraviolet-Irradiated and Intrinsically Aged Human Skin In Vivo

“…Anti-aging strategies target diverse mechanisms involved in skin aging, such as oxidative stress, mitochondrial dysfunction, cellular senescence, and epigenetic changes [1,[31][32][33][34]. For example, melatonin and its metabolites, non-calcemic secosteroids, lumisterol derivatives, polyphenols, and vitamins represent promising anti-aging agents [1,35,36]. It has also been reported that natural products, such as epigallocatechin-3-gallate, genistein, curcumin, and resveratrol, can affect the activity of various epigenetic regulating enzymes, such as DNA methyltransferase, HATs, and HDACs [37,38].…”