The Stress-Responsive Secretory Protein Adrenomedullin 2 Potently Induces Cell Cycle Arrest and Apoptosis in Human Hair Follicles

The study investigates the role of adrenomedullin 2 (ADM2) in human hair follicles (HFs) under stress conditions. Using an ex vivo model with 3 human HFs treated with recombinant human ADM2 (rhADM2) for 48 hours, researchers found that ADM2 significantly reduces cell proliferation and increases apoptosis in various HF compartments, except for the dermal papilla where apoptosis was not increased. ADM2 did not affect angiogenesis, as indicated by unchanged CD31 expression. These results suggest that ADM2 acts as a potent inhibitor of the cell cycle and induces apoptosis in HFs, contrasting with its previously known pro-proliferative and anti-apoptotic roles. ADM2 likely plays a crucial role in the integrated stress response pathway in HFs.