| [ Summary ] |
Intestinal stem cells represent a cell population which is the origin of all intestinal epithelial cells. They are defined as cells which can self-renew, and also have multi-potency. Thus, they can potentially differentiate into all the intestinal epithelial cell lineages. Therefore, intestinal epithelial stem cells play indispensable roles in the maintenance and homeostasis of the entire epithelial layer. Recent studies have made great advances possible in identifying and characterizing intestinal stem cells, based on their distinct gene expression patterns. Various stem cell-specific genes have been reported. Some have been proven to mark functionally validated stem cells in the "+4 position", or "crypt base columnar cells". These intestinal stem cells constitute the epithelial layer by "neutral competition", rather than a "hierarchical model". Furthermore, long-term ex-vivo culture techniques are now available for both scientific analysis and application in clinical settings. In this review, we overview recent advances in this field, and also give prospects for application of stem cell-based therapy for the treatment of refractory intestinal ulcers. |