Humans may one day be cured of diabetes by growing a new pancreas in another animal.

A recent study in Nature describes how the procedure was performed on a smaller scale, between a rat and a mouse. The researchers used mouse stem cells to grow a pancreas within a rat, then transplanted insulin-producing cells from that pancreas into the diabetic mouse. The new cells controlled the mouse’s diabetes.

According to the findings, because the cells were a genetic match to the mouse rather than the rat that grew them, the smaller rodent didn’t need the immunosuppression drugs normally required to prevent a body from rejecting a transplant — and at the same time had normal blood sugar levels for more than a year. 

Read: When Donated Organs Are Rejected

In addition to being an effective treatment for diabetes, the process is important because there are never enough organ donations to meet demand, when it comes to any serious medical condition. “Growing organs from one species in the body of another may one day relieve transplant shortages,” Stanford University Medical Center said in a statement. “The success of the interspecies transplantation suggests that a similar technique could one day be used to generate matched, transplantable human organs in large animals like pigs and sheep.”

A person with diabetes does not make enough insulin, the hormone that regulates the amount of sugar in your blood. Cells in the pancreas called beta cells produce insulin, and they form in clusters called islets, which is what the researchers — from Stanford and from the University of Tokyo’s Institute of Medical Science — were actaully transplanting from their rats to their mice.

The study says transplanting these cells is already “an established therapy for diabetes,” but where the cells come from counts. Previous experiments that were the reverse and attempted to grow a rat pancreas in a mouse, for example, didn’t produce enough of the insulin-producing cells because the mouse was too small for the rat’s needs. The new direction was much more successful.

“We found that the diabetic mice were able to normalize their blood glucose levels for over a year after the transplantation of as few as 100 of these islets,” senior author Dr. Hiromitsu Nakauchi, a Stanford genetics professor, said in the statement. “Furthermore, the recipient animals only needed treatment with immunosuppressive drugs for five days after transplantation, rather than the ongoing immunosuppression that would be needed for unmatched organs.”

Several months after the transplant, the mice had, in fact, “eliminated” all rat cells present. Nakauchi said that is “very promising for our hope to transplant human organs grown in animals because it suggests that any contaminating animal cells could be eliminated by the patient’s immune system after transplant.”

The team is now working on similar experiments with other organs, including kidneys, livers, and lungs.

Source: Yamaguchi T, Sato H, Kato-Itoh M, et al. Interspecies organogenesis generates autologous functional islets. Nature. 2017.

See also:

Device Smells Your Breath, Diagnoses Diabetes

What Hypoglycemia Does to Your Body