Correspondence should be addressed to:
Institute of Biochemistry, Medical Faculty, University Leipzig, Liebigstrasse 16, 04103 Leipzig
Wnt/beta-catenin signalling plays an important role in zonation of liver parenchyma and in patterning of hepatocyte heterogeneity. A characteristic marker of this heterogeneity is glutamine synthetase, which is expressed only in a subset of pericentrally located hepatocytes. To investigate, whether and how the Wnt/beta-catenin signalling pathway is involved a culture of hepatocytes was stimulated by LiCl. This resulted in an increase in the specific GS activity, indicating that the Wnt/beta-catenin pathway may participate in regulating GS levels. Affymetrix GeneChip oligonucleotide arrays were used to monitor the gene expression changes during a period from 2 to 24 hours after stimulation by LiCl. Samples from a cultivation without stimulation were used as controls. Based on the gene expression profiles a hypothetic signal transduction network was constructed by a reverse engineering algorithm. The network robustness was tested and the most stable structure was identified.