An Estrogen Receptor Pathway Regulates the Telogen-Anagen Hair Follicle Transition and Influences Epidermal Cell Proliferation

The study demonstrated that an estrogen receptor pathway in the dermal papilla regulated the transition from the telogen (resting) to anagen (growth) phase in hair follicles and influenced epidermal cell proliferation. Topical application of 17-beta-estradiol to mice skin arrested hair follicles in telogen and inhibited hair growth, while 17-alpha-estradiol had no effect. Conversely, the estrogen receptor antagonist ICI 182,780 induced hair follicles to enter anagen, promoting hair growth. Immunohistochemical staining showed high estrogen receptor expression in the dermal papilla during telogen. These findings suggested that estrogen receptors in the dermal papilla play a crucial role in hair cycle regulation and epidermal cell proliferation.