Implications of Constitutively Active Bone Morphogenetic Protein Signaling in Skin Morphogenesis and Skin Postnatal Homeostasis

The study investigated the role of Bone Morphogenetic Protein (BMP) signaling in skin morphogenesis and homeostasis using transgenic mice with a constitutively active BMPR1A receptor. It was found that high levels of BMP signaling impaired hair follicle morphogenesis, while epidermal morphogenesis remained normal but with disrupted differentiation and proliferation balance. Mice with low levels of transgene expression experienced progressive hair loss with age, indicating that BMP was crucial not only for morphogenesis but also for maintaining hair follicle homeostasis by balancing proliferation and quiescence in hair follicle stem cells.