小肠干细胞的命运调控

小肠上皮具有快速更新的能力,是研究成体干细胞的理想系统.小肠上皮由绒毛和隐窝两部分组成,而位于小肠隐窝底部的小肠干细胞是其持续更新的源泉.近年来,以Lgr5为代表的小肠干细胞标记物的发现、Lgr5+小肠干细胞的分离培养和多种转基因小鼠模型的出现,极大地促进了对小肠干细胞自我更新和分化调控的研究,使得人们可以更加深入地认识小肠干细胞命运决定的分子机制.本文简要综述了近年来人们对Wnt,BMP,Notch和EGF等信号如何在小肠干细胞命运调控中发挥作用的认识.

Regulation of Intestinal Stem Cell Fate

The remarkable ability of rapid self-renewal has made the intestinal epithelium become an ideal model for the study of adult stem cell regulation. The intestinal epithelium is organized into villus and crypts, and a population of intestinal stem cells located at the base of crypts is responsible for this constant self-renewal throughout the life. Recently, identification of the intestinal stem cell marker Lgr5, isolation and in vitro culture of Lgr5＋ intestinal stem cells and the use of transgenic mouse models have significantly facilitated the studies of intestinal stem cell homestasis and differentiation and greatly expanded our knowledge of the regulatory mechanisms underlying the intestinal stem cell fate determination. In this review, we summarize the current understanding of how signaling from Wnt, BMP, Notch and EGF in the stem cell niche modulates the intestinal stem cell fate.