Impairment of Hair-Inducing Capacity of 3D-Cultured Human Dermal Papilla Cells by the Ablation of STAT5

The study investigated the role of STAT5 in the hair-inducing capacity of human dermal papilla (DP) cells. Researchers used a small interfering RNA (siRNA) approach to knock down STAT5 in 3D-cultured DP spheres and then conducted a patch hair reconstitution assay. They found that when non-trichogenic 2D-cultured human DP cells were induced to form trichogenic DP spheroids, the expression of STAT5 and its target genes was elevated. However, hair follicle induction was significantly impaired when STAT5 (A or B) knock-down DP spheres were implanted with newborn mouse epidermal cells. This suggests that the enhanced trichogenicity of DP spheres is at least partly due to increased STAT5 levels, indicating that STAT5 plays a crucial role in the hair-inducing capacity of DP cells.