Role of Estrogen Receptor Signaling in the Control of the Hair Follicle Cycle

The study conducted 20 years ago aimed to understand the role of estrogen receptors (ER), ERα and ERß, in hair growth and control in both mice and humans. The research found that the expression of these receptors in mice was dependent on the hair cycle. In human scalp hair follicles, ERß expression decreased after treatment with prolactin or melatonin. The study also found sex-dependent differences in ERß expression in human scalp hair follicles. In female scalp hair follicles, estrogen (E2) inhibited hair shaft elongation and hair matrix keratinocytes proliferation. In contrast, E2 stimulated both the hair shaft elongation and hair matrix keratinocytes proliferation in male scalp hair follicles. The study also identified several novel estrogen-related target genes. The results suggested a crucial role of estrogens and their receptors in hair growth and control, highlighting the importance of sex-dependent differences and endogenous modulation.