Molecular Biology of Hair Morphogenesis: Development and Cycling

The document from August 15, 2003, reviews the progress in understanding the molecular mechanisms of hair follicle development and cycling. It explains that hair follicles go through a growth cycle consisting of anagen, catagen, and telogen phases, with specific molecular interactions required for each stage. Key signaling pathways and factors such as BMPs, EGF, Shh, p75NTR receptor, Wnt/ß-catenin/Lef-1, Hoxc13, Foxn1, Notch, and desmoglein 4 are involved in the regulation of hair follicle morphogenesis and cycling. The review also discusses the role of FGF5 in the anagen-catagen transition, neurotrophins and TGF-B1 in catagen induction, and the regulation of apoptosis and hair shedding. It emphasizes the importance of the dermal papilla's anti-apoptotic properties and the balance of growth stimulators and inhibitors, such as BMP4 and noggin, in hair cycle progression. The document suggests that understanding these molecular mechanisms could lead to treatments for hair growth disorders.