We report here that ultraviolet irradiation substantially reduced the mRNA and protein of the two major nuclear retinoid receptors, RAR-γ and RXR- α, in human skin in vivo. Pre-treatment with retinoic acid mitigated this loss of nuclear retinoid receptors. Ultraviolet irradiation caused a near- total loss of retinoic acid induction of two RAR/RXR target genes, cellular retinoic acid binding protein-II and RA 4-hydroxylase, but did not affect 1,25-dihydroxyvitamin D3 induction of the vitamin D receptor/RXR-regulated gene vitamin D 24-hydroxylase. In effect, ultraviolet irradiation causes a functional vitamin A deficiency that may have deleterious effects on skin function, contributing to skin photo-aging and carcinogenesis.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)