596 Retinoic acid receptor-related orphan receptor (ROR) agonists impact cellular responses to UV radiation in human keratinocytes

Retinoic acid receptor-related orphan receptor (ROR) agonists have been shown to regulate circadian rhythms in cultured cells and improve various disease outcomes animal models. Because expression of the core nucleotide excision repair protein XPA is governed by clock, we examined whether a natural synthetic ROR agonist (nobiletin SR1078, respectively) impact cellular responses UV radiation human keratinocytes. Interestingly, though these compounds little effect on total expression, they both reduce endopeptidase cathepsin L (CTSL), which known act several nuclear proteins, including at C-terminus under defined cell lysis conditions. We further show that NOB SR1078 slow keratinocyte proliferation varying extents while protects from lethal effects UVB radiation, it acts as photosensitizer response UVA radiation. Thus, results help better characterize potential functions keratinocytes exposed