Dermal β-catenin activity in response to epidermal Wnt ligands is required for fibroblast proliferation and hair follicle initiation

The study from April 15, 2012, found that dermal β-catenin activity, stimulated by epidermal Wnt ligands, is essential for fibroblast proliferation and the initiation of hair follicle development in mice. The absence of dermal Wnt signaling/β-catenin activity resulted in a failure to upregulate epidermal β-catenin activity and Edar expression, which are critical for hair follicle development. Conversely, forced activation of β-catenin signaling in the dermis caused a thickened dermis and enlarged, prematurely differentiated hair follicles. The research used tissue-specific genetic manipulation in mice and provided quantitative data on the proliferation index of dermal fibroblasts and cell density, as well as the number of hair follicles at various developmental stages. However, the exact number of embryos used was not specified. The findings underscore the importance of dermal β-catenin in skin differentiation and patterning, particularly in the early stages of hair follicle development.