Lab-Grown Organoids Transplanted into Mice Grow into Functioning Human Tissues

Scientists have made a major breakthrough when it comes to studying diseases of the intestine. They've managed to transplant "organoids" of functioning human intestinal tissue grow from pluripotent stem cells into mice. This creates an unprecedented model when it comes to studying human disease.

The scientists used induced pluripotent stem cells (iPSCs), which can become any tissue type in the body, in order to generate the intestinal organoids. Then, the researchers converted adult cells drawn from skin and blood samples into "blank" iPSCs. Then, they placed the stem cells into a molecular cocktail so that they would form intestinal organoids.

The next step was to engraft the human organoids into the capsule of the kidney of a mouse. This provided a necessary blood supply that allowed the organoid cells to grow into fully mature human intestinal tissue.

"These studies support the concept that patient-specific cells can be used to grow intestine," said Michael Helmrath, lead investigator in the new study, in a news release. "This provides a new way to study the many diseases and conditions that can cause intestinal failure, from genetic disorders appearing at birth to conditions that strike later in life, such as cancer and Crohn's disease. These studies also advance the longer-term goal of growing tissues that can replace damaged human intestine."

In fact, this step represents a major step forward when it comes to regenerative medicine. Since the researchers were able to produce significant amounts of fully functional, fully human intestine, this could eventually lead to treatments for those born with genetic defects that affect their digestive systems.

"The mucosal lining contains all the differentiated cells and continuously renews itself by proliferation of intestinal stem cells," said Helmrath. "In addition, the mucosa develops both absorptive and digestive ability that was not evident in the culture dish. Importantly, the muscle layers of the intestine also develop."

The findings are published in the journal Nature.