Dynamic Regulation of Retinoic Acid-Binding Proteins in Developing, Adult, and Neoplastic Skin Reveals Roles for β-Catenin and Notch Signaling

The study investigated the dynamic regulation of retinoic acid-binding proteins (CRABP1, CRABP2, and FABP5) in developing, adult, and neoplastic skin, revealing their regulation by β-catenin and Notch signaling. CRABP1 was found in the dermal papilla and tumor stroma, while CRABP2 and FABP5 were expressed in sebaceous glands, interfollicular epidermis, and hair follicles. RA treatment increased the expression of these proteins, while Wnt/β-catenin signaling downregulated them. Notch activation increased CRABP2 and FABP5 in the interfollicular epidermis but not in hair follicles. The study highlighted the complex regulation of RA signaling in skin and its interaction with β-catenin and Notch pathways, suggesting potential therapeutic targets for skin-related conditions.