Intestinal Enteroendocrine Lineage Cells Possess Homeostatic and Injury-Inducible Stem Cell Activity

Abstract

SUMMARY Several cell populations have been reported to possess intestinal stem cell (ISC) activity during homeostasis and injury-induced regeneration. Here, we explored inter-relationships between putative mouse ISC populations by comparative RNA-sequencing (RNA-seq). The transcriptomes of multiple cycling ISC populations closely resembled Lgr5+ ISCs, the most well-defined ISC pool, but Bmi1-GFP+ cells were distinct and enriched for enteroendocrine (EE) markers including Prox1. Prox1-GFP+ cells exhibited sustained clonogenic growth in vitro, and lineage-tracing of Prox1+ cells revealed long-lived clones during homeostasis and after radiation-induced injury in vivo. Single-cell mRNA-seq revealed two subsets of Prox1-GFP+ cells, one of which resembled mature EE cells while the other displayed low level EE gene expression but co-expressed tuft cell markers, Lgr5 and Ascl2, reminiscent of label-retaining secretory progenitors. Our data suggest that the EE lineage, including mature EE cells, comprise a reservoir of homeostatic and injury-inducible ISCs, extending our understanding of cellular plasticity and stemness.

Unsupervised Trajectory Analysis of Single-Cell RNA-Seq and Imaging Data Reveals Alternative Tuft Cell Origins in the Gut

“…While p-Creode has the potential to contribute to the ongoing debate on the existence of multiple reserve stem cell populations or whether reserve stem cells are dedifferentiated committed cells (Buczacki et al, 2013; Li et al, 2016; Yan et al, 2017), our limited dataset does not allow us to reach a definitive conclusion. Because of the overrepresentation of committed cell states, the resolution required to depict the more nuanced relationships among rare populations of reserve stem cells (~5 cells in a set of >2000 cells) was lacking.…”

“…It should be noted that the small intestine and colon are characterized by large differences in microbial content and load, and we observe differential dependence of Atoh1 on tuft cell development between the two regions. A recent study also suggested that tuft cells may share a common progenitor with subsets of enteroendocrine cells in the small intestine (Yan et al, 2017). Because of the importance of the microbiome in various ailments, modulating luminal-sensing tuft cell may be important in controlling allergic and inflammatory diseases.…”

Epithelial WNT Ligands Are Essential Drivers of Intestinal Stem Cell Activation

“…However, this is unlikely, as we did not observe BMI1 + cells at the CBC position (Figure 3), nor did we observe increased lineage tracing of BMI1 + daughter cells following RV infection (Figure S5). Recent work suggests that BMI1 + cells bear signatures of enteroendocrine cells, a differentiated, secretory cell type in the small intestine, making BMI1 + cells a possible early progenitor committed to the enteroendocrine lineage (Jadhav et al, 2017; Yan et al, 2017a). Together, these results argue that RV-induced villus damage also does not affect the enteroendocrine progenitor population.…”

The Role of Nrf2 in the Response to Normal Tissue Radiation Injury

“…In contrast to the radiation response of the +4 Bmi1 CreER;Rosa26 YFP cells, CBC Lgr5-eGFP-IRES-CreERT2 cell numbers were significantly reduced 48 h after 12 Gy irradiation, although sporadic regeneration was observed 7 days postirradiation. Yan et al (44) then expanded on these studies using RNA-seq to characterize stem cell inter-relatedness. They found that the CBC signature genes (e.g., Lgr5, Ascl2 and Olfm4) were also expressed at low levels in Bmi1-GFP+ cells while Lgr5+ cells express 4+ markers Bmi1, mTert and Hopx, but at low levels.…”