Regulation of asialoglycoprotein receptor expression in the proliferative state of hepatocytes

It is necessary to proliferate hepatocytes and to increase the number of he patocytes for development of bioartificial liver (BAL) and reconstitutive t herapy. But usually the cell has a precarious balance between proliferation and differentiation: as the cell proliferation increases, functional diffe rentiation decreases. Therefore, it is desirable for the hepatocytes to be functional by differentiation as a material for such clinical use not to be proliferative. In this study, we investigated the background of hepatocyte proliferation for the springboard of control between proliferation and dif ferentiation of hepatocytes, and we focused attention to the asialoglycopro tein receptors (ASGP-R) of the hepatocytes. Partially hepatectomized (PH) r ats were used as a model animal. When the isolated hepatocytes were plated onto the artificial extracellular matrix of poly-(N-p-vinylbenzyl-O-beta -D -galactopyranosyl-D-gluconamide) (PVLA) having galactose residues as cell-s pecific ligand, the rate of adhesion was decreased along with liver regener ation. Interestingly, the release of the ASGP-R from hepatocytes in serum a fter PH in vivo and reduction of ASGP-R of the hepatocytes in the prolifera tive state occurred due to cell growth in vitro. It is suggested that the A SGP-R on the hepatocyte surface during the differentiation was released in the proliferative state. (C) 2001 Academic Press.