Experimental Modulation of the Differentiated Phenotype of Keratinocytes from Epidermis and Hair Follicle Outer Root Sheath and Matrix Cells
December 1991
in “
Annals of the New York Academy of Sciences
”
TLDR ORS and hair matrix cells balance growth and differentiation better than normal keratinocytes, with human dermal fibroblasts crucial for proper differentiation.
The study investigated the differentiation of keratinocytes from the epidermis and hair follicle outer root sheath (ORS) and matrix cells by analyzing keratin profiles as differentiation markers. It was found that ORS and hair cortex contained distinct sets of keratins, with ORS cells expressing "soft" keratins and hair cortex containing "hard" alpha-keratins. In culture, ORS and hair matrix cells formed stratified epithelia expressing epidermal differentiation markers, maintaining a better balance between growth and differentiation compared to normal keratinocytes (NEK). In transplants on nude mice, tissue homeostasis was normalized across all epithelial cell types. When embedded in Matrigel, ORS and NEK formed spheroids with epidermoid differentiation, with NEK showing greater differentiation than ORS. The presence of human dermal fibroblasts (HDF) was crucial for spheroid formation and differentiation, as replacing HDF with follicular dermal papilla (DP) cells reduced spheroid size and differentiation.
