JunB Defines Functional And Structural Integrity Of The Epidermal-Pilosebaceous Unit In The Skin

The study investigated the role of JunB, a transcription factor, in maintaining the integrity of the epidermal-pilosebaceous unit in the skin. It was found that JunB regulated epidermal stem cells and sebaceous glands by balancing progenitor cell proliferation and differentiation, and preventing lineage infidelity. JunB deficiency led to a dermatitis-like condition similar to seborrheic dermatitis, with impaired sebaceous glands and altered lipid profiles. During wound healing, some JunB-deficient epidermal progenitors switched fate, forming new sebaceous glands. The study identified dysregulated Notch signaling as a cause of these phenotypes, and pharmacological inhibition of Notch signaling was able to restore normal function in JunB knockout mice. This highlighted a critical role for JunB in the homeostasis and pathology of epidermal-pilosebaceous stem cells.