Department of Dermatology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Department of Dermatology, San Francisco Co-Director Epithelial Section Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, 1700 Owens Street, San Francisco, CA, 94158, USA.
Stem Cell Res Ther. 2024 Mar 13;15(1):76. doi: 10.1186/s13287-024-03670-y.
A traditional view is that stem cells (SCs) divide slowly. Meanwhile, both embryonic and pluripotent SCs display a shorter cell cycle duration (CCD) in comparison to more committed progenitors (CPs).
We examined the in vitro proliferation and cycling behavior of somatic adult human cells using live cell imaging of passage zero keratinocytes and single-cell RNA sequencing.
We found two populations of keratinocytes: those with short CCD and protracted near exponential growth, and those with long CCD and terminal differentiation. Applying the ergodic principle, the comparative numbers of cycling cells in S phase in an enriched population of SCs confirmed a shorter CCD than CPs. Further, analysis of single-cell RNA sequencing of cycling adult human keratinocyte SCs and CPs indicated a shortening of both G1 and G2M phases in the SC.
Contrary to the pervasive paradigm, SCs progress through cell cycle more quickly than more differentiated dividing CPs. Thus, somatic human adult keratinocyte SCs may divide infrequently, but divide rapidly when they divide. Additionally, it was found that SC-like proliferation persisted in vitro.
传统观点认为干细胞（SCs）分裂缓慢。同时，与更成熟的祖细胞（CPs）相比，胚胎和多能性SCs 表现出更短的细胞周期持续时间（CCD）。
我们使用传代零角质形成细胞的活细胞成像和单细胞 RNA 测序来检查体外成年人体细胞的增殖和细胞周期行为。
我们发现了两种角质形成细胞群体：一种具有短 CCD 和延长的近指数生长，另一种具有长 CCD 和终末分化。应用遍历原理，对富含 SC 的细胞周期中 S 期的循环细胞的比较数量证实了 SC 的 CCD 短于 CPs。此外，对循环成人角质形成细胞 SC 和 CPs 的单细胞 RNA 测序分析表明，SC 中的 G1 和 G2M 期都缩短了。
与普遍的范式相反，SCs 通过细胞周期的速度快于更分化的分裂 CPs。因此，体细胞人类成年角质形成细胞 SC 可能很少分裂，但分裂时分裂迅速。此外，还发现 SC 样增殖在体外持续存在。
