Intestinal Epithelial Lgr5⁺ Stem Cell Niche and Organoids

Over the past 10years, insights into the biology of intestinal stem cells have rapidly increased. The adult intestinal epithelium represents one of the most suitable models to study tissue stem cells. It is the rapidly self-renewing tissue and the design of its basic units, the crypt-villus is highly stereotypical. Since the discovery of Lgr5⁺ stem cells at the base of intestinal crypts, it has become possible to unveil the molecular mechanisms that control homeostasis of the stem cells, including the extrinsic signaling cues from the crypt niche. Based on these insights, in vitro propagation of murine and human intestinal stem cells in the form of ever-expanding organoids has become possible. The three-dimensional culture technology of organoids opens new avenues for studying fundamental questions on the stem cells and their niche, but has also allowed several applications in personalized medicine. Here, we discuss these recent developments and insights.