1184 Inhibitory effects of secreted frizzled related protein 1 on melanocytes: Implications on solar lentigo

Solar lentigo (SL) is a common hyperpigmented lesion occurring on sun-exposed skin, and sign of photodamage aging. WNT/β-catenin signaling promotes melanogenesis via activating MITF, the master regulator melanocytes. Secreted frizzled related proteins (sFRP) are antagonists that inhibit binding WNT ligands to their receptors. However, recent studies have reported sFRP2 activates melanocytes, suggesting opposing effects sFRP proteins. In this study, we focused sFRP1, whose function in melanocytes unclear, examined its regulation possibly SL formation. Paired skin biopsies were obtained from peri-lesional (PL) female volunteers aged 50-68 years. Dermal RNA was extracted expression levels sFRP1 measured with real-time qPCR. The recombinant protein (rsFRP1) determined morphology, cell number, viability, cultured normal human several types cells by qPCR, Western blotting, ELISA. mRNA level decreased areas compared PL areas. Treatment rsFRP1 dendricity, proliferation, tyrosinase activity. Expression highest keratinocytes, evident fibroblasts, dermal papilla cells. These results suggest produced different negatively regulates reduced involved pathogenesis SL. Enhancing may be potential therapeutic approach for hyperpigmentation.