Notch Signaling Regulates Late-Stage Epidermal Differentiation and Maintains Postnatal Hair Cycle Homeostasis

The 2011 study investigated the role of Notch signaling in late-stage epidermal differentiation and postnatal hair cycle homeostasis. Using genetically modified mice, the researchers found that Notch signaling is crucial for maintaining normal hair growth and cycle progression. Inhibition of Notch signaling led to a delay in hair follicle differentiation, an extended anagen phase, and eventually hair loss. The study also found that the absence of Pofut1, a critical component of the Notch signaling pathway, led to abnormalities in the granular layer of the epidermis, altered filaggrin processing, and aberrant telogen morphology. These findings suggest that Notch signaling is essential for the homeostasis of bulge stem cells during the hair cycle transition and that its loss leads to DNA damage response and loss of stem cell characteristics.