Bone morphogenetic protein (BMP) signaling controls hair pigmentation by means of cross-talk with the melanocortin receptor-1 pathway

The study investigated the role of bone morphogenetic protein (BMP) signaling in hair pigmentation, particularly its interaction with the melanocortin type 1 receptor (MC-1R) pathway. Using transgenic mice overexpressing the BMP antagonist noggin, researchers found that these mice lacked the typical yellow band in their dorsal hair, displaying near-black pigmentation instead. This change was linked to reduced Agouti signal protein levels and increased microphthalmia transcription factor expression. The wild-type hair color was restored by administering a synthetic MC-1R antagonist, indicating a cross-talk between BMP and MC-1R pathways. BMP-4 was shown to stimulate Agouti expression in keratinocytes and dermal fibroblasts, suggesting that BMP signaling regulates Agouti protein expression and influences the balance between pheomelanogenesis and eumelanogenesis during hair growth.