Dynamic Nestin expression during hair follicle maturation and the normal hair cycle

Nestin, a type-VI intermediate filament protein, serves as a marker for neural stem cells, and is also known to be expressed in follicle stem cells. Hair follicles go through repeated cycles of anagen (growth), catagen (regression) and telogen (quiescence) throughout the life of mammals following morphogenesis. In the present study it was demonstrated that in mice, the maturation of hair follicles includes the period between morphogenesis and the first anagen (4 weeks of age). Skin samples from Nestin‑green fluorescent protein (GFP)+ mice at different hair follicle stages were collected, and immunostaining for Nestin and Ki67 was performed. It was identified that during morphogenesis, Nestin‑GFP expression was rarely detected and it gradually increased during maturation (0‑4 weeks) in hair follicle dermal cells. In mature hair follicle dermal cells, Nestin and the proliferation marker Ki67 were highly expressed in anagen, while during telogen, they were markedly decreased. Additionally, lineage tracing data demonstrated that peri‑follicular Nestin+ cells during morphogenesis differentiated into cluster of differentiation 31+ cells.