Alk1 Acts in Non-Endothelial VE-Cadherin+ Perineurial Cells to Maintain Nerve Branching During Hair Homeostasis

The study reveals that Alk1 in non-endothelial VE-cadherin+ perineurial cells is essential for maintaining nerve branching during hair homeostasis. Using various mouse models and techniques, researchers identified these cells as crucial for nerve encapsulation and structural integrity, impacting hair follicle function. Loss of Alk1 led to increased nerve branching and disorganization, linked to reduced laminin in the basement membrane. This expands the known functions of VE-cadherin/Alk1 beyond vascular roles to include nerve homeostasis, with potential implications for vascular and nerve diseases.