Replacement of Lost Lgr5-Positive Stem Cells through Plasticity of Their Enterocyte-Lineage Daughters

Abstract

Intestinal crypts display robust regeneration upon injury. The relatively rare secretory precursors can replace lost stem cells, but it is unknown if the abundant enterocyte progenitors that express the Alkaline phosphate intestinal (Alpi) gene also have this capacity. We created an Alpi-IRES-CreERT2 (Alpi(CreER)) knockin allele for lineage tracing. Marked clones consist entirely of enterocytes and are all lost from villus tips within days. Genetic fate-mapping of Alpi(+) cells before or during targeted ablation of Lgr5-expressing stem cells generated numerous long-lived crypt-villus "ribbons," indicative of dedifferentiation of enterocyte precursors into Lgr5(+) stems. By single-cell analysis of dedifferentiating enterocytes, we observed the generation of Paneth-like cells and proliferative stem cells. We conclude that the highly proliferative, short-lived enterocyte precursors serve as a large reservoir of potential stem cells during crypt regeneration.

Intestinal epithelial organoids fuse to form self-organizing tubes in floating collagen gels

“…4B). Occasionally, organoids formed from the rims of crypt holes, in agreement with in vivo findings by us and others: committed progenitor cells can revert to a stem cell phenotype upon depletion of the initial stem cell compartment (Tian et al, 2011;van Es et al, 2012;Tetteh et al, 2016). However, we have never seen in vitro or in vivo evidence for fully differentiated cells (enterocytes, goblet cells, or Paneth cells) to revert to a stem cell state or to initiate organoids.…”

Using primary murine intestinal enteroids to study dietary TAG absorption, lipoprotein synthesis, and the role of apoC-III in the intestine

“…Ultimately, R-spondin removal results in a higher amount of terminally differentiated cells, but this comes at the cost of LGR5+ niche, which means that replenishment of differentiated epithelial cells is lost. It has recently been reported that there is an additional niche of differentiated epithelial enterocytes that reverts to multipotent ISCs when LGR5+ stem cells are ablated (28,36). This may explain one of the significant issues we faced with our primary enteroid cultures, which stubbornly retained "stem-ness" and high expression of LGR5 throughout culture.…”

“…Previous studies in enteroids have focused on stem cell biology, lineage tracing, and Na + /H + exchange (23,(26)(27)(28). We asked whether enteroids were able to accomplish TAG absorption, lipoprotein synthesis, and lipoprotein secretion, which are major functions of the intestine.…”

Dissecting the stem cell niche with organoid models: an engineering-based approach

“…These emerging technologies will facilitate studies that aim to address key concepts in stem cell biology, such as the influence of the niche on cell plasticity, as well as how the physical properties of the stem cell niche direct stem cell self-organization and, in turn, stem cell fate. For example, progenitors that are restricted to the enterocyte lineage during normal intestinal homeostasis can dedifferentiate to become stem cells and repopulate the crypt following damage (Tetteh et al, 2016). Similarly, in the prostate both luminal and basal cells can produce in vitro organoids containing both lineages, but only basal cells give rise to all lineages when transplanted in vivo (Goldstein et al, 2008;Karthaus et al, 2014).…”