Comparative Spatial Transcriptomic and Single-Cell Analyses of Human Nail Units and Hair Follicles Show Transcriptional Similarities between the Onychodermis and Follicular Dermal Papilla

This study used spatial transcriptomics and single-cell RNA sequencing to compare human nail units and hair follicles, revealing significant transcriptional similarities between the onychodermis (OD) and the dermal papilla (DP). Key findings include shared gene expression patterns in Wnt and BMP signaling pathways, which are crucial for the growth and differentiation of both structures. The research involved analyzing 16,606 cells, highlighting the role of BMP signaling in inducing hard keratin gene expression in nail matrix keratinocytes. These results suggest that the onychodermis is analogous to the dermal papilla, with BMP5 playing a crucial role in nail matrix keratinocyte differentiation, potentially informing future therapeutic strategies for conditions affecting both tissues.