Restoration of Hair-Inductive Activity of Cultured Human Follicular Keratinocytes by Co-Culturing with Dermal Papilla Cells

In the 2018 study, researchers found that co-culturing human outer root sheath (ORS) cells with human dermal papilla (DP) cells for 5 days restored the hair-inductive activity of the ORS cells. When these co-cultured cells were implanted into nude mice along with neonatal mouse dermal cells, they successfully induced hair formation, unlike monocultured ORS cells. Microarray analysis showed that a number of genes were differentially regulated in the co-cultured ORS cells, indicating that DP cells can influence ORS cell gene expression through paracrine factors. This suggests a potential new approach for treating hair loss by preparing competent human epidermal cells. The gene expression changes were confirmed by real-time PCR in three independent experiments, with significant differences noted (p < 0.05). The research was funded by the National Research Foundation of Korea.