Expression of Nerve Growth Factor in Skin Tissues and Its Effect on the Proliferation of Outer Root Sheath Cells in Cashmere Goats

The study investigated the expression of nerve growth factor (NGF) and its receptor TrkA in the skin of Liaoning cashmere goats and their role in hair follicle cycling. The researchers found that both NGF and TrkA were persistently expressed in skin tissue, with significantly higher levels during the anagen (growth) phase compared to the catagen (regression) phase. High immunoreactivity of TrkA was observed in the outer root sheath (ORS), and NGF in both the internal root sheath (IRS) and ORS during anagen. Additionally, NGF was found to significantly promote the proliferation of isolated ORS cells at concentrations of 20 ng/mL or 100 ng/mL, but this effect was inhibited by K252a, a TrkA inhibitor. These results suggest that NGF may play a role in hair follicle growth and reconstruction via TrkA-dependent pathways.