Role of Beta-Catenin Signaling in Adult Epidermal Cell Fate Specification

The study investigated the role of β-catenin signaling in adult epidermal cell fate using transgenic mice. Activation of β-catenin signaling prompted resting hair follicles to enter the growth phase and led to the formation of new ectopic hair follicles from existing follicles, interfollicular epidermis, and sebaceous glands, resulting in trichofolliculomas. While transient activation initiated hair follicle morphogenesis, continuous activation was necessary to maintain hair follicle tumors. The study also highlighted the influence of β-catenin signaling on the Hedgehog and Notch pathways and the vitamin D receptor. Additionally, the research explored the relationship between β-catenin and c-Myc in epidermal cell lineage choice and developed an in vitro model for analyzing lineage selection at the single-cell level. This approach demonstrated the benefits of controlling β-catenin signaling to study epidermal stem cell self-renewal and differentiation, with potential applications in understanding adult skin homeostasis.