PPAR-gamma agonist, ciglitazone, increases pigmentation and migration of human melanocytes.

Peroxisome proliferator-activated receptors (PPARs) play an important role in cellular responses. It was reported that three subtypes of PPAR are expressed in human melanocytes. In this study, we investigated the effects of the PPAR-gamma agonist, ciglitazone, on pigmentation and migration of human melanocytes. Ciglitazone stimulated the melanin content of cells and cultured skin. This increase in pigmentation was due to the stimulation of tyrosinase activity and expression of tyrosinase and microphthalmia-associated transcription factor protein of the melanocytes. Migration was increased after ciglitazone treatment, which was observed by the Boyden chamber checkerboard analysis and a scratch motility assay. These results suggest the regulatory role of PPAR-gamma in pigmentation and migration of human melanocytes.