复层扁平上皮干细胞群体的异质性参与维持口腔粘膜对生理应激的反应，这一成果由美国北卡罗莱纳大学医学院Scott E. Williams研究小组近日取得。2019年12月5日出版的国际学术期刊《细胞—干细胞》发表了这一研究成果。

一般认为，复层扁平上皮中的干细胞遵守非层级的单祖细胞模型。使用谱系追踪和遗传标记保留测定，研究人员发现口腔的硬腭上皮表现出独特的显著增殖异质性。

研究人员确定驻留在候选微环境、交界区（JZ）内以前未表征的、不常分裂的干细胞群体。JZ干细胞倾向于通过平面对称分裂自我更新，响应咀嚼压力并促进伤口愈合，而频繁分裂的细胞位于JZ外部，优先通过垂直不对称分裂进行更新，并且对损伤的反应较弱。LRIG1富集在动态平衡中不常分裂的群体中，可响应组织压力动态改变表达，并促进静止，而Igfbp5则优先标记快速增长且易于分化的群体。

这些研究将口腔粘膜确立为研究上皮干细胞群体及其对组织应激反应的重要模型系统。

附：英文原文

Title: Heterogeneity within Stratified Epithelial Stem Cell Populations Maintains the Oral Mucosa in Response to Physiological Stress

Author: Kevin M. Byrd, Natalie C. Piehl, Jeet H. Patel, Won Jae Huh, Inês Sequeira, Kendall J. Lough, Bethany L. Wagner, Pauline Marangoni, Fiona M. Watt, Ophir D. Klein, Robert J. Coffey, Scott E. Williams

Issue&Volume: 2019/12/05

Abstract: Stem cells in stratified epithelia are generally believed to adhere to a non-hierarchicalsingle-progenitor model. Using lineage tracing and genetic label-retention assays,we show that the hard palatal epithelium of the oral cavity is unique in displayingmarked proliferative heterogeneity. We identify a previously uncharacterized, infrequently-dividingstem cell population that resides within a candidate niche, the junctional zone (JZ).JZ stem cells tend to self-renew by planar symmetric divisions, respond to masticatorystresses, and promote wound healing, whereas frequently-dividing cells reside outsidethe JZ, preferentially renew through perpendicular asymmetric divisions, and are lessresponsive to injury. LRIG1 is enriched in the infrequently-dividing population inhomeostasis, dynamically changes expression in response to tissue stresses, and promotesquiescence, whereas Igfbp5 preferentially labels a rapidly-growing, differentiation-pronepopulation. These studies establish the oral mucosa as an important model system tostudy epithelial stem cell populations and how they respond to tissue stresses.

DOI: 10.1016/j.stem.2019.11.005

Source: https://www.cell.com/cell-stem-cell/fulltext/S1934-5909(19)30460-6