Sox2-Positive Dermal Papilla Cells Specify Hair Follicle Type in Mammalian Epidermis

The study demonstrated that Sox2-positive dermal papilla cells played a crucial role in specifying hair follicle types in mammalian epidermis. Sox2 was initially expressed in all dermal papillae at E16.5, but later became restricted to certain types, specifically in guard/awl/auchene follicles in postnatal skin. The research utilized transgenic mice to isolate and compare Sox2+ (GFP+) CD133+ cells with Sox2- (GFP-) CD133+ cells, revealing distinct gene expression profiles and pathway activations. Sox2+ cells were associated with Wnt, FGF, and BMP pathways, while Sox2- cells were linked to hedgehog, IGF, Notch, and integrin pathways. Skin reconstitution assays showed that the absence of Sox2+ CD133+ cells led to the failure of awl/auchene hair formation, highlighting the importance of Sox2-positive cells in determining specific hair follicle types.