Human Sensory Neurons Modulate Melanocytes Through Secretion of RGMB

Melanocytes are surrounded by diverse cells including sensory neurons in our skin, but their interaction and functional importance has been poorly investigated. In this study, we found that melanocytes and nociceptive neurons contact more in human skin color patch tissue than control. Co-culture with human iPS cell-derived sensory neurons significantly induced morphogenesis and pigmentation of human melanocytes. To reveal melanocytes-stimulating factors secreted from neurons, we performed proteomic analyses and identified RGMB in the sensory neuron-conditioned media. RGMB protein induced morphogenesis and melanin production of melanocytes, demonstrating that RGMB is a melanocyte-stimulating factor released from sensory neurons. Transcriptome analysis suggested that the melanosome transport machinery could be controlled by RGMB, which led us to identify vesicle production response of melanocytes upon RGMB treatment. This study discovered a role of sensory neurons to modulate multiple aspects of human melanocytes through secretion of a key factor RGMB. Overall design: RNA-seq of melanocytes upon recombinant RGMB treatment and RGMB depleted IPSC-derived sensory neuron conditioned media.