1. Academic Validation
  2. 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

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

  • Redox Biol. 2019 Jun;24:101206. doi: 10.1016/j.redox.2019.101206.
Anyamanee Chaiprasongsuk 1 Zorica Janjetovic 2 Tae-Kang Kim 2 Stuart G Jarrett 3 John A D'Orazio 3 Michael F Holick 4 Edith K Y Tang 5 Robert C Tuckey 5 Uraiwan Panich 6 Wei Li 7 Andrzej T Slominski 8
Affiliations

Affiliations

  • 1 Department of Dermatology, University of Alabama at Birmingham, USA; Department of Pharmacology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
  • 2 Department of Dermatology, University of Alabama at Birmingham, USA.
  • 3 Department of Toxicology and Cancer Biology, The Markey Cancer Center, College of Medicine, University of Kentucky, Lexington, KY, USA.
  • 4 Department of Medicine, Boston University, MA, USA.
  • 5 School of Molecular Sciences, The University of Western Australia, Perth, WA, Australia.
  • 6 Department of Pharmacology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
  • 7 Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA.
  • 8 Department of Dermatology, University of Alabama at Birmingham, USA; VA Medical Center, Birmingham, AL, USA. Electronic address: [email protected].
Abstract

We tested whether novel CYP11A1-derived vitamin D3- and lumisterol-hydroxyderivatives, including 1,25(OH)2D3, 20(OH)D3, 1,20(OH)2D3, 20,23(OH)2D3, 1,20,23(OH)3D3, lumisterol, 20(OH)L3, 22(OH)L3, 20,22(OH)2L3, and 24(OH)L3, 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/cm2, 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/cm2 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)2D3 or CYP11A1-derived vitamin D3- 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 D3 and lumisterol hydroxy-derivatives represent promising anti-photodamaging agents.

Keywords

Epidermal keratinocytes; Lumisterol (L(3)); Nuclear factor E2-related factor 2 (Nrf2); Photoprotective effects; Ultraviolet B (UVB); Vitamin D(3) hydroxy-derivatives.

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