Identification of Hair Shaft Progenitors That Create a Niche for Hair Pigmentation

In 2017, researchers identified progenitor cells in the hair matrix that differentiate from follicular epithelial cells and are crucial for hair growth and pigmentation. These progenitors express the transcription factor KROX20, and their depletion leads to halted hair growth, highlighting their importance as precursors to structural hair cells. Additionally, these KROX20+ cells are responsible for producing stem cell factor (SCF), which is essential for maintaining differentiated melanocytes that provide pigmentation to hair. This study uncovered the role of hair matrix progenitors in creating a supportive niche for follicular melanocytes through SCF, thereby regulating hair color and growth.