Title: Region-specific differences in human epidermal differentiation at a single-cell level
Abstract: Palmoplantar skin, the thickened skin found on the palms of the hands and soles of the feet, is marked by its increased epidermal thickness and specific pattern of keratin expression. Although these differences have previously been noted, their transcriptomic differences have yet to be characterized on the single cell level. We utilized scRNA-seq data from non-volar (hip) and volar (palm and sole) skin from human subjects to characterize these differences, focusing specifically on the keratinocyte populations. Our analysis indicated increased immune function in non-volar keratinocytes, which may contribute to volar skin’s differential susceptibility to disease. Additionally, these results pointed to greater differences within palmoplantar skin, i.e. between the palm and the sole, than previously appreciated. Pseudotime analysis points to the presence of two distinct keratinocyte differentiation trajectories that are conserved across the multiple body sites.