Role of Bulge Epidermal Stem Cells and TSLP Signaling in Psoriasis

The study investigated the role of bulge hair follicle stem cells (HF-SCs) and thymic stromal lymphopoietin (TSLP) signaling in psoriasis. Researchers found reduced expression of c-JUN and JUNB in bulge HF-SCs in patients with scalp psoriasis. Using mouse models with inducible deletion of these genes, they demonstrated that mutant bulge HF-SCs could initiate epidermal hyperplasia and skin inflammation. TSLP was identified as a key factor promoting proliferation of neighboring non-mutant epidermal cells. Blocking TSLP in psoriasis-like mice reduced skin inflammation and epidermal proliferation. The study highlighted the distinct roles of HF-SCs and inter-follicular epidermal cells in psoriasis, providing new insights into epidermal cell interactions in inflammatory skin diseases.