RXR? ablation in epidermal keratinocytes enhances UVR-induced DNA damage, apoptosis, and proliferation of keratinocytes and melanocytes.

ABSTRACT: We show here that keratinocytic nuclear receptor retinoid X receptor-? (RXR?) regulates mouse keratinocyte and melanocyte homeostasis following acute UVR. Keratinocytic RXR? has a protective role in UVR-induced keratinocyte and melanocyte proliferation/differentiation, oxidative stress-mediated DNA damage, and cellular apoptosis. We discovered that keratinocytic RXR?, in a cell-autonomous manner, regulates mitogenic growth responses in skin epidermis through secretion of heparin-binding EGF-like growth factor, GM-CSF, IL-1?, and cyclooxygenase-2 and activation of mitogen-activated protein kinase pathways. We identified altered expression of several keratinocyte-derived mitogenic paracrine growth factors such as endothelin 1, hepatocyte growth factor, ?-melanocyte stimulating hormone, stem cell factor, and fibroblast growth factor-2 in skin of mice lacking RXR? in epidermal keratinocytes (RXR?(ep-/-) mice), which in a non-cell-autonomous manner modulated melanocyte proliferation and activation after UVR. RXR?(ep-/-) mice represent a unique animal model in which UVR induces melanocyte proliferation/activation in both epidermis and dermis. Considered together, the results of our study suggest that RXR antagonists, together with inhibitors of cell proliferation, can be effective in preventing solar UVR-induced photocarcinogenesis.

SUBMITTER: Wang Z 

PROVIDER: S-EPMC3073005 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature