767 Regulation of XPC by 7-dehydrocholesterol in keratinocytes and fibroblasts

7-dehydrocholesterol (7DHC) is a precursor of cholesterol biosynthesis and its pathological accumulation is linked to the photosensitive Smith-Lemli-Opitz syndrome. 7DHC is photoconverted by ultraviolet radiation (UV) in epidermal keratinocytes to pre-Vitamin D3 which isomerizes and is enzymatically hydroxylated to other biologically active forms. Exogenously administered vitamin D3 hydroxylated derivatives in human keratinocytes promote upregulation of XPC, a vital component of nucleotide excision repair pathway, suggesting a compensatory response to DNA damage incurred upon UV exposure during Vitamin D photosynthesis.
Source: Journal of Investigative Dermatology - Category: Dermatology Authors: Tags: Photobiology Source Type: research