Hair Cycle Regulation by a Mitochondrially Localized Protein: Is MPZL3 a Central Component of the Elusive Hair Cycle Clock?

In a study from May 2021, researchers investigated the role of Myelin Protein Zero-like 3 (MPZL3) in hair follicle cycling in mice. They found that MPZL3, a protein localized in mitochondria and involved in epidermal differentiation, also regulates the hair cycle clock (HCC). Mice lacking functional MPZL3 showed delayed transition from the growth phase to the resting phase after normal hair follicle development, followed by an accelerated hair cycle with a quicker transition back to the growth phase. MPZL3 expression was found to oscillate with the hair cycle and was localized to key areas of hair cycle regulation. The study also demonstrated that the absence of MPZL3 in skin epithelia led to a similar accelerated hair cycle, suggesting that MPZL3-dependent signals from skin epithelia control the HCC. These findings suggest that mitochondria play a significant role in hair cycle control and that MPZL3 is a central component of the HCC, providing potential new targets for alopecia treatment. The specific number of mice used in the study was not mentioned in the summary provided.