# Iron Deficiency Inhibits the Proliferation of Intestinal Stem Cells and Induces Their Differentiation to Enterocytes

## TL;DR

Iron deficiency reduces intestinal stem cell proliferation and pushes them to become enterocytes, affecting gut health and repair.

## Contribution

This study reveals a novel mechanism linking iron deficiency to altered intestinal stem cell behavior via the Notch signaling pathway.

## Key findings

- Iron deficiency reduces Lgr5-positive intestinal stem cells and Ki67-positive proliferating cells.
- Iron deficiency increases Vil1 expression, indicating a shift toward enterocyte differentiation.
- Modulation of the Notch signaling pathway is associated with iron deficiency-induced differentiation of intestinal stem cells.

## Abstract

Objectives: Iron deficiency impairs intestinal mucosal structure and function, yet its impact on intestinal stem cells (ISCs) remains unclear. This study was therefore designed to examine how iron deficiency affects the proliferation and differentiation of ISCs. Methods: Iron-deficient mouse and enteroid models were established. Expression of key cell markers was analyzed using Western blot, qPCR, and immunofluorescence. Results: Iron deficiency led to structural impairment of the intestinal mucosa, characterized by decreased small intestinal villus height. In iron-deficient mice, expression of ChrA (enteroendocrine cell marker), Lyz (Paneth cell marker), and Muc2 (goblet cell marker) was significantly downregulated across duodenum, jejunum and ileum, whereas Vil1 (enterocyte marker) expression increased. Moreover, both Lgr5 (an ISC marker) expression and the number of Ki67-positive proliferating cells were significantly reduced, along with a decrease in Ki67 transcriptional levels under iron-deficient conditions. Similarly, deferoxamine (DFO)-treated enteroids showed fewer Lgr5-positive ISCs, downregulation of Lgr5, Lyz and Muc2, and upregulation of Vil1. RNA-seq further confirmed that iron deficiency skews ISC differentiation toward absorptive lineage. This shift was associated with modulation of the Notch signaling pathway: upregulation of the ligand Dll1, receptors Notch2 and Notch3, and the protease ADAM10, alongside downregulation of the negative regulator Atoh1. These findings indicate that Notch pathway activation promotes enterocyte differentiation under iron deprivation. Conclusions: Iron deficiency suppressed the proliferation of ISCs and induced their differentiation toward enterocytes, which is associated with the modulation of the Notch signaling pathway, providing a mechanistic insights for impaired intestinal repair and the potential for nutrient-targeted therapies.