Functional human intestinal tissue can be generated by growing human stem cells in the lab and then transplanting them into mice, according to a study in Nature Medicine. This human-mouse model of the intestine may be used to study developmental processes, gastrointestinal disease and to test new therapies for certain disorders.
It has previously been shown that embryonic as well as induced pluripotent stem cells could be grown in the lab to form intestinal tissue. However, as these models grow, they do not fully copy the physiological and anatomical changes and function of intestinal tissue in the body.
Michael Helmrath and colleagues found that if this lab grown tissue was implanted within the kidney tissue of mice, it matured further than it did in the lab and developed into a complex structure resembling the human small intestine.
Anatomically, the tissue developed characteristic features of the small intestine, including crypts and villi, and contained several different intestinal cell types. This tissue also exhibited digestive functions, such as absorption of particles into the bloodstream of the mouse and digestive enzyme activity. The authors also found that surgical removal of a portion of the mouse intestine resulted in growth and adaptation of the implanted human tissue, suggesting the human intestinal tissue can respond to signals released into the circulation of the mouse.