Role Of Notch Signalling In Intestinal Stem Cell Renewal

In the intestinal epithelium, the Notch signaling pathway regulates cell fate under the influence of Wnt  signaling.

Notch signaling helps maintain the intestinal stem cell or ISC pool in the intestinal crypt.

Here, the Notch ligands expressed on the Paneth cells interact with the Notch receptor on the ISCs and inhibit their differentiation, allowing the ISCs to maintain their stem-cell state in the crypt.

As the ISCs begin differentiation, the Notch signaling pathway also determines the fate of transit-amplifying, TA cells, which differentiate into either absorptive or secretory cell types.

Some TA cells express high levels of Notch ligands and prevent the differentiation of adjacent cells by activating their Notch receptors.

The Notch receptor-expressing TA cells keep dividing and move upward, away from the Wnt signals, before differentiating into absorptive cells.

In contrast, Notch ligand expressing TA cells stop dividing and differentiate into secretory cells.