Human hepatocyte cell lines proliferating as cohesive spheroid colonies inalginate markedly upregulate both synthetic and detoxificatory liver function

Background/Aims: Bio-artificial liver support systems for treatment of hepa tic failure require maintained expression of hepatocyte function in vitro. We studied cultures of human hepatocyte cell-lines proliferating within alg inate beads, investigating the hypothesis that 3-dimensional cohesive colon ies of hepatocyte cell-lines would achieve polarity and cell-to-cell contac t resulting in upregulation of function. Methods: HepG2 and HHY41 human cell lines in alginate beads were cultured f or >20 days. Results: Proliferation was maintained for 20 days. Production of albumin, p rothrombin, fibrinogen, alpha-1-acid glycoprotein and alpha-l-antitrypsin w as maintained throughout, maximal at days 8-10, when upregulation was 300-1 100% compared with monolayer cultures at similar cell number per unit volum e. Detoxificatory functions: ethoxyresorufin deethylase activity, androsten edione metabolism, and urea synthesis from arginine was also increased seve ralfold. Function returned to pre-freezing levels within 18 h of thawing af ter cryopreservation of cells in alginate, Electron microscopy revealed sph erical colonies of cells of cuboidal shape, with cell-to-cell contact via d esmosomes and junctional complexes, abundant microvilli, and cytoplasmic ap pearances suggesting transcriptionally active hepatocytes. Conclusion: Hepatocyte cell-lines, proliferating in alginate express a rang e of liver-specific functions at levels approaching those found in vivo, re levant to their use in liver support systems. (C) 2001 European Association for the Study of the Liver. Published by Else vier Science B.V. All rights reserved.