In-vitro reconstitution of hepatic tissue architectures with neonatal mouse liver cells using three-dimensional...

Stem cells have the potential to differentiate into multiple lineages, and the capabilities to self-renew, and reconstitute tissues following transplantation. Thus, stem cells are expected to be useful for regenerative medicine; however, the mechanisms that regulate the reconstitution of three-dimensional (3-D) tissues remain to be elucidated. To study such mechanisms, we have established a novel procedure of 3-D culture that supports the formation of tissues from isolated cells, including hepatic stem/progenitor cells in vitro. We cultured neonatal mouse liver cell populations, including hepatic stem/progenitor cells, in a simulated microgravity environment produced by a Rotating Wall Vessel bioreactor. After 8 days in culture, we obtained a 3-D tissue architecture. Histological analysis showed that bile duct structures secreting mucin formed complicated tubular branches in the peripheral region. In the non-bile duct structure region, we observed mature hepatocytes that were capable of producing albumin and storing glycogen. Thus, we were able to establish a novel 3-D culture system that is able to reconstitute functional hepatic tissue architecture from isolated neonatal mouse liver cells.