UZH discovers colon stem-cell niche

The renewal of cells in the lining of the intestines is driven by stem cells located in small folds of the epithelium, as the lining is known, explained UZH in a statement. However, this regeneration process is only activated when GLi1-positive cells secrete a Wnt signal.  

Konrad Basler from the Institute of Molecular Life Sciences and a group of UZH researchers have now discovered the GLi1-positive cells responsible for providing the activating signal to the stem cells. They are nearby in the folds of the epithelium.  

“If the Gli1-positive cells are eliminated or unable to secrete Wnt proteins, the activation signal is lost,” explained Basler in the statement. “Consequently, the colon’s stem cells as well as the epithelium will perish, and the organism dies.”

In tests on mice, the researchers showed that if Wnt signaling is stimulated excessively, the stem cells divide in an uncontrolled manner. Mice with mutations in the Wnt signaling pathways developed polyps, from which colon cancer later develops, according to Basler.

In response to inflammation of the colon, however, the cells increased in line with the level of inflammation. “The cells we’ve discovered are thus not only essential for healthy organisms, but are also essential when it comes to repairing a damaged intestinal epithelium,” said Basler.

The research group’s discovery therefore has relevance for a range of intestinal diseases, from inflammation to cancer.