Hair follicle stem cells mobilize and expand to help repair the skin’s barrier by differentiating into epidermal lineages . Credit: Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development at The Rockefeller University
Now, new research demonstrates that once stem cells have entered this state, known as lineage plasticity, they cannot function effectively in either role until they choose a definitive fate. In a screen to identify key regulators of this process, retinoic, the biologically active form of Vitamin A, surfaced as a surprising rheostat. The findings shed light on lineage plasticity, with potential clinical implications.
To better understand how the body regulates this process, Fuchs and her team screened small molecules for their ability to resolve lineage plasticity in cultured mouse hair follicle stem cells, under conditions that mimicked a wound state. They were surprised to find that retinoic acid, a biologically active form of vitamin A, was essential for these stem cells to exit lineage plasticity and then be coaxed to differentiate into hair cells or epidermal cells in vitro.
“By defining the minimal requirements needed to form mature hair cell types from stem cells outside the body, this work has the potential to transform the way we approach the study of hair biology,” Tierney says.