Short Cell Cycle Duration Is a Phenotype of Human Epidermal Stem Cells

This study challenges the traditional view that human epidermal stem cells (SCs) divide slowly by demonstrating that, although SCs may divide infrequently, they progress through cell cycle phases more rapidly than committed progenitors (CPs) when they do divide. Using live cell imaging and single-cell RNA sequencing, researchers found that SCs have a significantly shorter cell cycle duration (CCD) compared to CPs, with median CCDs of 19 hours for SCs (n=1017) versus 30 hours for CPs (n=174). The study also revealed that SCs have shortened G1 and G2 phases, while the S phase duration remains consistent between SCs and CPs. These findings suggest that SCs, despite their infrequent division, exhibit a rapid progression through the cell cycle phases.