Hunting the Hair Cycle Clock: Evidence That Mitochondrially Localized MPZL3 Is a Key Element in Murine and Human Hair Follicles
TLDR MPZL3 is important for controlling the hair growth cycle in mice and humans.
The study explores the role of Myelin Protein Zero-like 3 (MPZL3), a protein localized to the mitochondria, in the hair cycle clock (HCC) which controls the timing and velocity of hair follicle cycles. Previous research showed that MPZL3 is expressed in the secondary hair germ, a key area for hair cycle regulation, and that mice without MPZL3 had accelerated hair follicle cycling, suggesting MPZL3 acts as a brake on hair growth. The current study found that MPZL3 is also expressed in human hair follicles and that reducing MPZL3 expression in cultured scalp hair follicles extended the growth phase and delayed the regression phase, likely by reducing TGF-β2 expression. MPZL3 silencing also reduced mitochondrial-specific VDAC1/PORIN expression. These findings suggest that mitochondria play a larger role in hair cycle control than previously thought, and that MPZL3-dependent signaling in hair follicle keratinocytes is central to the HCC. This suggests that targeting MPZL3-dependent signaling pathways could provide new strategies for therapeutic hair cycle manipulation.
