Regulation of differentiation and proliferation of rat hepatocytes by lactose-carrying polystyrene.

We noticed that hepatocytes recognize the structure of oligosaccharides via asialoglycoprotein receptors and synthesized lactose-carrying styrene polymer (PVLA) as an asialoglycoprotein model. We found that the regulation of differentiated function and proliferation of hepatocytes that were cultured on polystyrene dishes can be achieved by varying the amount of PVLA coated on the dishes. The 3H-thymidine uptake of cultured hepatocytes is low for cells cultured on dishes coated with high amounts of PVLA in which the hepatocytes are round and is highest for those cultured on dishes with a low PVLA coating level in which the hepatocytes are spread in shape. Moreover, bile acid release as a typical differentiated function of hepatocytes was maintained at higher levels in hepatocytes attached on dishes coated with a high level of PVLA. Our results indicated that regulation of differentiated function and proliferation in hepatocytes could be achieved by specific ligand-mediated recognition of microscopic surface structure. Thus, it may be possible to regulate proliferation and differentiation of hepatocytes by design of the culturing substrata.