A study from Nagoya University shows that human stem cell-derived pituitary tissue can restore hormone production in primates, potentially offering a new treatment for hypopituitarism.

Researchers at Nagoya University in Japan have successfully transplanted pituitary tissue grown from human stem cells into a macaque monkey. The procedure restored critical hormone signals in the primate, which had previously undergone the surgical removal of its own pituitary gland. This study, published in the journal Stem Cell Research & Therapy, marks the first time lab-grown human pituitary cells have been shown to survive and function within a primate model.

Restoring Hormone Function

The pituitary gland is responsible for releasing hormones like ACTH, which triggers the adrenal glands to produce cortisol. When the gland fails, patients develop hypopituitarism and must rely on daily hormone pills that often fail to mimic the body's natural, fluctuating needs. By using organoids—small, lab-grown masses of tissue derived from human stem cells—researchers aimed to provide a more natural method of hormone regulation.

Testing in Mice and Primates

The team first tested the organoids in mice, where the tissue produced ACTH for over six months and extended the animals' lifespans without causing tumors. In the macaque monkey, the transplanted tissue functioned for six weeks, successfully elevating ACTH and cortisol levels while slowing weight loss associated with hormone deficiency. Researchers used immune-suppressing drugs to prevent rejection, and follow-up samples taken three months later confirmed that some transplanted cells had survived.