Division of Gastroenterology, Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA.
Transl Res. 2010 Sep;156(3):180-7. doi: 10.1016/j.trsl.2010.06.003. Epub 2010 Jul 3.
The intestinal epithelium contains a rapidly proliferating and perpetually differentiating epithelium. The principal functional unit of the small intestine is the crypt-villus axis. Stem cells located in the crypts of Lieberkühn give rise to proliferating progenitor or transit amplifying cells that differentiate into the 4 major epithelial cell types. The study of adult gastrointestinal tract stem cells has progressed rapidly with the recent discovery of several putative stem cell markers. Substantial evidence suggests 2 populations of stem cells: long-term quiescent (reserved) and actively cycling (primed) stem cells. These cells are in adjoining locations and are presumably maintained by the secretion of specific proteins generated in a unique microenvironment or stem cell niche surrounding each population. The relationship between these 2 populations, as well as the cellular sources and composition of the surrounding environment, remains to be defined, and is an active area of research. In this review, we will outline progress in identifying stem cells and in defining epithelial-mesenchymal interactions in the crypt. We will summarize early advances using stem cells for therapy of gastrointestinal disorders.
肠上皮含有快速增殖和不断分化的上皮细胞。小肠的主要功能单位是隐窝-绒毛轴。位于李氏隐窝中的干细胞产生增殖的祖细胞或过渡扩增细胞，分化为 4 种主要的上皮细胞类型。随着最近发现的几个假定的干细胞标记物，成人胃肠道干细胞的研究取得了快速进展。大量证据表明存在 2 种干细胞群体：长期静止（保留）和活跃循环（启动）干细胞。这些细胞位于相邻位置，可能由在每个群体周围的独特微环境或干细胞龛中产生的特定蛋白质的分泌来维持。这两个群体之间的关系，以及周围环境的细胞来源和组成，仍有待确定，这是一个活跃的研究领域。在这篇综述中，我们将概述在鉴定干细胞和定义隐窝中上皮-间充质相互作用方面的进展。我们将总结使用干细胞治疗胃肠道疾病的早期进展。
