Epidermal GRK2 Knockout Triggers a Hair Loss Phenotype with Features Resembling Immune-Mediated Alopecias

The study investigates the role of GRK2 in hair follicle (HF) homeostasis using a keratinocyte-specific knockout mouse model. Deletion of GRK2 leads to significant hair loss due to the formation of abnormal cyst-like structures in the hair follicles, which displace and destroy the dermal papilla, promoting hair loss. These cysts attract immune cells and undergo apoptosis, resembling features of immune-mediated alopecias such as Alopecia Areata (AA). The GRK2 knockout mice exhibit transcriptomic similarities to AA, suggesting shared mechanisms. The findings highlight the importance of GRK2 in maintaining HF homeostasis and regulating interactions between hair follicles and immune cells.