Controlling MTORC1 Activity as a Novel Therapeutic Strategy for Managing Human Hair Growth and Pigmentation
TLDR Blocking mTORC1 activity with rapamycin could help increase hair pigmentation and growth, potentially reversing gray hair.
The study investigates the role of mechanistic Target of Rapamycin Complex 1 (mTORC1) in human hair follicle (HF) biology, particularly focusing on hair growth and pigmentation. Using HF organ culture, researchers found that inhibiting mTORC1 with rapamycin significantly increased melanin production, gp100 expression, tyrosinase activity, and melanocyte dendricity in healthy human anagen scalp HFs. This effect was linked to increased a-MSH production by keratinocytes, especially in graying HFs, where rapamycin could even re-stimulate melanogenesis. Conversely, excessive mTORC1 activity reduced HF pigmentation. Additionally, rapamycin prolonged the anagen phase and inhibited hair matrix keratinocyte apoptosis, suggesting its potential for managing hair growth and pigmentation disorders. The findings highlight mTORC1's fundamental role in HF cycling and pigmentation, proposing rapamycin and rapalogs as novel therapeutic strategies.
