Abstract
Liver tissue consists hepatocytes and nonparenchymal liver cells (NPC) and hepatocytes in vivo are surrounded by NPC, and the differentiation and growth of hepatocytes are regulated by their interactions with NPC. Therefore, it is important to coculture hepatocytes with NPC for establishing hepatocyte culture system which has structural organization similar to liver in order to develop hepatic module system. In this study, our attempt to culture hepatocytes with NPC on PVLA (poly-N-p-vinyl benzyl-D-lactonamide) as a polymer model of asialoglycoprotein for establishing hepatocyte culture system is described. Attached hepatocytes on PVLA remarkably formed anchored multilayer aggregations resembling micro-liver without supplemented growth factors, when cocultured with NPC. Hepatocytes in multilayer aggregations which were induced by NPC, retained enhanced expression of differentiated functions such as the secretion of albumin, and also survived for a long time. It seems likely that hepatocytes cultured with NPC experienced the stable environment of liver tissue in vivo, and as a result exhibited enhanced expression of differentiated functions and long-term survivability. Therefore, PVLA as a synthetic substratum is an efficacious substratum for the coculture of hepatocytes and NPC which results in a culturing system similar to liver tissue in vivo. The culture system described here has useful potentials for the development of hybrid artificial liver and the study of the process in liver regeneration.
