Transplanted placental cells successfully detected in mouse pancreas after birth

The pancreas is a complex organ comprising multiple cell types that regulate blood glucose levels through hormones, such as insulin, and support digestion by producing digestive enzymes. These researchers previously developed an intraplacental transplantation method whereby pancreatic progenitor cells are injected into the placenta of a pregnant mouse and delivered to the developing fetus. However, whether transplanted cells could become incorporated into pancreatic tissue had not been demonstrated.

In this study, cells derived from embryonic pancreatic buds at embryonic day 12.5 (E12.5) were transplanted via the placenta into recipient embryos at embryonic day 9.5 (E9.5). After birth, donor-derived cells were detected within the pancreas in some recipient mice in regions that corresponded to pancreatic islets, acinar tissue, and ducts, although their distribution varied among recipient mice.

The researchers also examined mice lacking the Pdx1 gene, which is crucial for pancreatic development. In separate experimental cohorts, some transplanted Pdx1-deficient mice showed detectable circulating insulin or transient postnatal increases in blood glucose levels. However, among the Pdx1-deficient recipients for which anatomical records were available, no macroscopically detectable organized pancreatic tissue was observed in the examined anatomical region. Because the localization of donor-derived cells was not determined in these animals, the source of the detected insulin remains unclear.

This study highlights that pancreatic bud-derived cells transplanted intraplacentally into developing fetuses can subsequently be detected within the pancreas after birth. These findings provide new insights into the behavior of transplanted pancreatic cells during development. In future, the researchers plan to further investigate the migration and differentiation of induced pluripotent stem cell-derived pancreatic progenitor cells after intraplacental transplantation.