Cholesterol Homeostasis: Links to Hair Follicle Biology and Hair Disorders

The 2019 review article examines the critical role of cholesterol in hair follicle function and how disruptions in cholesterol homeostasis can lead to hair disorders such as primary cicatricial alopecia, congenital hypertrichosis, and androgenic alopecia. It discusses the molecular mechanisms by which cholesterol affects hair follicle cell proliferation and differentiation, the importance of cholesterol in skin and keratinocyte function, and the need for further research to fully understand cholesterol transport mechanisms in hair follicles. The review also explores the role of cholesterol in signaling pathways that regulate hair growth and cycling, local steroid hormone synthesis in hair follicles, and the potential links between dyslipidemia and hair loss disorders. It suggests that understanding cholesterol movement in hair follicles could provide insights into hair growth regulation and the development of hair disorders. Additionally, the document mentions the inconclusive evidence regarding the impact of statins on hair loss and the need for more research to understand how hair follicle cell populations handle cholesterol. It also notes that mutations in genes related to cholesterol transport and metabolism are associated with hair loss conditions, and that future studies should focus on the targeted knockout of specific enzymes within the hair follicle to elucidate the role of local steroid hormone synthesis in hair disorders.