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

Area of Science:

• Gastroenterology
• Stem Cell Biology
• Developmental Biology

Background:

• Intestinal stem cells (ISCs) are crucial for maintaining gut homeostasis and regeneration.
• Multiple cell populations have shown potential ISC activity, but their inter-relationships remain unclear.

Purpose of the Study:

• To investigate the relationships between different putative mouse ISC populations.
• To characterize the stem cell potential of Prox1+ cells within the intestinal epithelium.

Main Methods:

• Comparative RNA-sequencing (RNA-seq) of various ISC populations.
• Single-cell mRNA sequencing (scRNA-seq) of Prox1-GFP+ cells.
• In vitro clonogenic assays.
• In vivo lineage tracing after radiation injury.

Main Results:

• Transcriptomes of most cycling ISC populations resemble Lgr5+ ISCs.
• Bmi1-GFP+ cells are distinct and enriched for enteroendocrine (EE) markers like Prox1.
• Prox1-GFP+ cells demonstrate sustained in vitro clonogenic growth and form long-lived clones in vivo.
• scRNA-seq identified two Prox1-GFP+ subsets: mature EE cells and a progenitor-like population expressing EE, tuft cell, Lgr5, and Ascl2 markers.

Conclusions:

• The enteroendocrine lineage, including mature EE cells, represents a significant reservoir of ISCs.
• These EE-derived ISCs are capable of both homeostatic maintenance and injury-induced regeneration.
• Findings expand the understanding of cellular plasticity and stemness in the intestinal epithelium.