Hair Follicle Chemosensation: TRPM5 Signaling Is Required for Anagen Maintenance

The study explored the role of TRPM5 in human hair follicle biology, focusing on its importance in maintaining the anagen phase of hair growth. TRPM5 was highly expressed in the outer root sheath keratinocytes of hair follicles. Its knockdown resulted in increased apoptosis and transition to the catagen phase, underscoring its necessity for anagen maintenance. Activation of TRPM5 by compounds such as 2-heptanone and 2,5-dimethylpyrazine promoted hair growth and sustained anagen, whereas inhibition with triphenylphosphine oxide (TPPO) triggered catagen. The findings suggested that TRPM5 could be a potential target for treating hair disorders, highlighting its unique role in supporting hair follicle keratinocyte proliferation, unlike other TRP channels that inhibit hair growth.