Culture System of Bile Duct-Like Cystic Structures Derived from Human-Inducible Pluripotent Stem Cells

Inducible pluripotent stem (iPS) cells are multipotent stem cells that are produced by gene transfer of reprogramming factors to somatic cells. They are thought to be an important source of regenerative medicine because of their pluripotency and self-renewal ability. Although the liver has high regeneration ability, continuous death of hepatocytes due to chronic inflammation leads to liver cirrhosis and liver carcinoma. With regard to such serious liver diseases, liver transplantation is used as a complete cure, but there is a problem of donor shortage. Therefore, transplantation therapy using liver tissue generated from stem cells in vitro is expected.We are developing a system to induce the differentiation of cholangiocytes, one of important non-parenchymal cells in living liver tissue, from human iPS cells. Bile duct-like cystic structures can be induced by purifying human iPS cell-derived hepatoblasts expressing hepatic progenitor cell surface markers and inducing differentiation under appropriate culture conditions. These cells are considered to be useful in constructing a hepatic organoid that reproduces the liver structure of the living body.