189 Integrating single-cell and spatial transcriptomics of human hair follicles to define transcriptional signature of follicular dermal papilla

The follicular dermal papilla (DP) is a specialized hair mesenchymal cell that plays pivotal roles in follicle (HF) development and morphogenesis. Although transcriptome data exists for HF, characterization of human DPs at the single-cell level has been unsatisfactory due to limited number DP cells under dissociation condition. To generate high proportion cells, we manually isolated anagen HFs from three scalp specimens used these populations RNA sequencing (scRNA-seq). In addition, Digital Spatial Profiling (DSP) provide expression profile with spatial information. Using computational deconvolution methods, integration scRNA-seq DSP estimated epithelial abundance hair-specific regions interest confirm utility identifying molecular markers mesenchyme. Analysis HF revealed RSPO4, WNT5A, TRPS1, CRABP1, APCDD1, EDN3, RSPO3, LEF1, BMP4, BMP7, NRG2 are specifically expressed whereas MME, LGR4, LGR5, FZD1, CXCL14, TAGLN were mainly sheath. markers, performed situ hybridization (RNA-ISH). RNA-ISH, observed presence MSX1 HOXC13 mRNA matrix BMP5, DKK3, RSPO4 LGR6 DP. Collectively, through transcriptomic profiling, could establish foundation understand characteristics