Delayed Hair Cycle in Mnd2 Mutant Mice Lacking HtrA2 Serine Protease Activity

This study investigated the role of HtrA2 serine protease activity in hair cycle regulation using mnd2 mutant mice. The researchers observed that mnd2 mice exhibited a delay in the transition from the telogen to anagen phase of the hair cycle, which was associated with a differential skin color change compared to wild-type mice. Histological and molecular assays revealed that HtrA2 inactivation led to growth retardation of adipocytes in the subcutaneous skin layer, contributing to the delayed hair cycle. These findings highlight the essential role of HtrA2 in regulating the adipogenesis-associated hair cycle.