Neurogenic Skin Inflammation in Stress-Triggered Inhibition of Hair Growth in Mice Is Promoted via Nerve Growth Factor-Dependent Pathways

The study explored the role of nerve growth factor (NGF) in stress-triggered hair loss in mice, highlighting the brain-hair follicle axis. Researchers found that stress increased NGF expression, which in turn elevated substance P (SP) release, contributing to hair loss. Stress also upregulated the NGF receptor p75 and downregulated the TrkA receptor. Neutralizing NGF with antibodies inhibited stress-induced hair cycle changes, apoptosis, and immune cell activation. Conversely, injecting recombinant NGF mimicked stress effects, increasing SP-positive neurons. The findings suggested that stress-induced NGF release promotes neurogenic inflammation, leading to hair loss through interactions between sensory nerves and immune cells.