Expression of Hair-Related Keratins in a Soft Epithelium: Subpopulations of Human and Mouse Dorsal Tongue Keratinocytes Express Keratin Markers for Hair, Skin, and Esophageal Types of Differentiation

The study explored the expression of hair-related keratins in the soft epithelium of human and mouse dorsal tongue keratinocytes, revealing that these cells express keratin markers associated with hair, skin, and esophageal differentiation. In Hoxc13 null mice, defects such as malformed nails and filiform tongue papillae were observed, along with a lack of vibrissae and pelage hairs due to premature hair fracture, despite normal-looking hair follicles. This suggested that Hoxc13 might play a crucial role in hair and filiform papilla development by regulating hair keratin gene expression. Further research in Hoxc13-overexpressing mice indicated deregulation of various hair follicle-specific genes, supporting the hypothesis of Hoxc13's involvement in hair keratin synthesis.