Akt2 and SGK3 Are Both Determinants of Postnatal Hair Follicle Development

The study investigated the roles of SGK3 and Akt2 in postnatal hair follicle development in mice. SGK3 was previously known to be crucial for hair follicle development, with SGK3-deficient mice showing abnormal follicle cycling that improved with age. However, mice lacking Akt1, Akt2, or Akt3 did not exhibit similar abnormalities. The researchers created Akt2/SGK3 double knockout (DKO) mice and found that these mice had more severe hair growth defects than SGK3-deficient mice alone, with issues persisting with age. The defects included accelerated catagen and anagen phases, irregular follicle orientation, and increased sebaceous gland expression. These were linked to a failure in β-catenin accumulation and proliferation in follicle matrix cells. Both Akt2 and SGK3 were shown to stimulate β-catenin-dependent transcription in keratinocytes, suggesting their redundant roles in regulating hair follicle cell proliferation and morphogenesis.