Anyamanee ChaiprasongsukZorica JanjetovicTae Kang KimCynthia J. SchwartzRobert C. TuckeyEdith K.Y. TangChander RamanUraiwan PanichAndrzej T. SlominskiBirmingham VA Medical CenterThe University of Western AustraliaThe University of Alabama at BirminghamFaculty of Medicine, Siriraj Hospital, Mahidol UniversityChulabhorn Royal Academy2020-12-282020-12-282020-12-02International Journal of Molecular Sciences. Vol.21, No.24 (2020), 1-1814220067166165962-s2.0-85097521379https://repository.li.mahidol.ac.th/handle/20.500.14594/60385© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Lumisterol (L3) is a stereoisomer of 7-dehydrocholesterol and is produced through the photochemical transformation of 7-dehydrocholesteol induced by high doses of UVB. L3 is enzymatically hydroxylated by CYP11A1, producing 20(OH)L3, 22(OH)L3, 20,22(OH)2L3, and 24(OH)L3. Hydroxylumisterols function as reverse agonists of the retinoic acid-related orphan receptors α and γ (RORα/γ) and can interact with the non-genomic binding site of the vitamin D receptor (VDR). These intracellular receptors are mediators of photoprotection and anti-inflammatory activity. In this study, we show that L3-hydroxyderivatives significantly increase the expression of VDR at the mRNA and protein levels in keratinocytes, both non-irradiated and after UVB irradiation. L3-hydroxyderivatives also altered mRNA and protein levels for RORα/γ in non-irradiated cells, while the expression was significantly decreased in UVB-irradiated cells. In UVB-irradiated keratinocytes, L3-hydroxyderivatives inhibited nuclear translocation of NFκB p65 by enhancing levels of IκBα in the cytosol. This anti-inflammatory activity mediated by L3-hydroxyderivatives through suppression of NFκB signaling resulted in the inhibition of the expression of UVB-induced inflammatory cytokines, including IL-17, IFN-γ, and TNF-α. The L3-hydroxyderivatives promoted differentiation of UVB-irradiated keratinocytes as determined from upregulation of the expression at the mRNA of involucrin (IVL), filaggrine (FLG), and keratin 14 (KRT14), downregulation of transglutaminase 1 (TGM1), keratins including KRT1, and KRT10, and stimulation of ILV expression at the protein level. We conclude that CYP11A1-derived hydroxylumisterols are promising photoprotective agents capable of suppressing UVB-induced inflammatory responses and restoring epidermal function through targeting the VDR and RORs.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyChemical EngineeringChemistryComputer ScienceArticleSCOPUS10.3390/ijms21249374