712 UV-induced reduction in polycomb repression promotes epidermal pigmentation

Ultraviolet (UV) radiation is a prime environmental stressor that our epidermis exposed to on daily basis. To avert UV-induced damage, epidermal stem cells (EpSCs) become pigmented via process of heterotypic interaction between melanocytes and EpSCs, however the molecular mechanisms this are not well understood. In study we show function key chromatin regulator, Polycomb complex, was reduced upon UV exposure in human mouse epidermis. Genetic ablation subunits murine mimicking depletion exposure, results an increased number subsequent pigmentation. Genome-wide transcriptional studies regulates expression UV-responsive genes identify type II collagen as critical secreted regulator melanogenesis Altogether, findings how UV-exposure induces Polycomb-mediated changes EpSCs affect melanocyte behavior promote