526 The involvement of gremlin 1 in particulate matter-induced melanogenesis

Particulate matter (PM) is known as a major concern for human health because it closely associated with mortality and morbidity from respiratory cardio- neurovascular diseases. Recently, has been reported that PM can aggravate allergic skin diseases by affecting the barrier or inducing inflammation. Along our previous reports promotes melanin production via ER-mediated IRE1α signaling pathway, we also performed high-throughput single-cell RNA sequencing analysis using PM-delivered ex vivo tissues to find out target molecules in different cell types, keratinocytes, melanocytes, fibroblasts, etc. Among many candidates, gremlin 1 was induced keratinocytes fibroblasts. Gremlin secreted protein bone morphogenetic (BMP) antagonist inhibits transforming growth factor-beta pathway. As works BMP antagonist, plays role cancer proliferation, angiogenesis, osteoblast differentiation. In skin, protects fibroblasts ultraviolet radiation-induced damage. However, whether be effect of on melanocytes have not investigated. this study, utilized recombinant investigate association between melanogenesis primary epidermal (PHEMs). The type secretes treatment keratinocytes. PHEMs melanogenesis-related production. Vascular endothelial factor receptor 2 evaluated pathway involved 1-related melanogenesis. Our data suggest stimulate secretion, especially PM-induced induce PHEMs.