Np63 Regulates Stem Cell Dynamics in the Mammalian Olfactory Epithelium

The study demonstrated that the transcription factor p63 (Trp63) was crucial for the differentiation of horizontal basal cells (HBCs) in the olfactory epithelium (OE), which were reserve stem cells activated by severe epithelial damage. The research showed that p63 was expressed by adult HBCs and was necessary for their differentiation, as evidenced by the absence of HBC formation in p63-null mice, while other OE cell types formed normally. The role of p63 in HBC differentiation was also observed in regenerating rat OE. Additionally, p63 protein was downregulated in HBCs when they were activated to become multipotent progenitor cells, indicating a p63-dependent molecular switch for activating reserve stem cells.