Histochemical Studies on Cutaneous Stem Cells in Human Fetal Skin

The study investigated the distribution and characteristics of cutaneous stem cells in human fetal skin during embryogenesis, using immunohistochemical methods to analyze their differentiation into epidermis and hair follicles. It found that integrins β1 and K19 were coexpressed in the undifferentiated epidermis, with β1 expression downregulated during follicular keratinization. K14 was differentially expressed in the basal and spinous layers, while K10 was in the differentiated spinous and granular layers. Epidermal progenitor cells were mainly located in the basal layer and hair follicle structures, expressing integrins β1, K19, K14, and PCNA. The study concluded that basal layer cutaneous cells contribute to epidermis and hair follicle development, with mesenchymal cues also playing a role in hair follicle formation and cycling.