This layer, known as the intestinal epithelium, is coated with many small indentations known as crypts. At the bottom of each crypt is a small pool of epithelial stem cells, which constantly replenish the specialized cells of the intestinal epithelium, which only live for about five days. These stem cells can become any type of intestinal epithelial cell, but don't have the pluripotency of embryonic stem cells, which can become any cell type in the body.
If scientists could obtain large quantities of intestinal epithelial stem cells, they could be used to help treat gastrointestinal disorders that damage the epithelial layer. Recent studies in animals have shown that intestinal stem cells delivered to the gut can attach to ulcers and help regenerate healthy tissue, offering a potential new way to treat ulcerative colitis.
Using those stem cells to produce large populations of specialized cells would also be useful for drug development and testing, the researchers say. With large quantities of goblet cells, which help control the immune response to proteins found in food, scientists could study food allergies; with enteroendocrine cells, which release hunger hormones, they could test new treatments for obesity.
"If we had ways of performing high-throughput screens on large numbers of these very specific cell types, we could potentially identify new targets and develop completely new drugs for diseases ranging from inflammatory bowel disease to diabetes," Karp says.
Controlling cell fate
In 2007, Hans Clevers, a professor at the Hubrecht Institute in the Netherlands, identified a marker for intestinal epithelial stem cells a protein called Lgr5. Clevers, who is an author of the new Nature Methods paper, also ide
|Contact: Sarah McDonnell|
Massachusetts Institute of Technology