FGF22 Secreted by Hair Papilla Cells Regulates Hair Follicle Stem Cell Proliferation and Differentiation

This study explores the role of FGF22, secreted by dermal papilla cells (DPCs), in regulating hair follicle stem cell (HFSC) proliferation and differentiation. Using a DPC-HFSC co-culture system, researchers found that FGF22 overexpression enhances HFSC viability and proliferation by activating Wnt/β-Catenin, Sonic Hedgehog, and Notch signaling pathways while inhibiting BMP pathways. Conversely, FGF22 knockout reduces HFSC proliferation by 25% and increases apoptosis by 1.81-fold. These findings suggest FGF22 is crucial for hair follicle cycle transition and early growth phase entry, offering potential applications in regenerative medicine and hair loss treatment. The study was conducted using fine-wool sheep cells with a sample size of 3 biological repetitions.