A Meeting of Two Chronobiological Systems: Circadian Proteins Period1 and BMAL1 Modulate the Human Hair Cycle Clock

The study demonstrated that circadian proteins PER1 and BMAL1 significantly modulated the human hair cycle, particularly the transition from the growth phase (anagen) to the regression phase (catagen). In organ-cultured human hair follicles (HFs), silencing BMAL1 or PER1 prolonged the anagen phase, suggesting these genes as potential therapeutic targets for influencing hair growth. The research indicated that peripheral core clock genes were integral to the human hair cycle clock, offering insights into potential treatments for hair growth disorders. The study involved a small sample size, with scalp skin and HF units collected from 3 females and 10 males.