Epidermis Reconstructed from the Outer Root Sheath of Human Hair Follicle: Effect of Retinoic Acid

The study demonstrated that a multilayered and well-differentiated epidermis could be generated in vitro from the outer root sheath of human hair follicles on de-epidermized dermis. This reconstructed epidermis exhibited features similar to normal human epidermis, including the expression of specific markers for keratinocyte differentiation. The transition from outer root sheath cells to interfollicular keratinocytes occurred without living fibroblasts. Retinoic acid modulated the differentiation of the epidermis in a dose-dependent manner. The culture system on dead dermis was easier to handle than those on collagen-fibroblast lattices, suggesting its potential as a wound-healing model and a tool for pharmacological studies on reconstructed skin.