beta-Catenin is critical for early postnatal liver growth.

The Wnt/beta-catenin pathway plays an important role in embryonic liver development, morphogenesis, and organogenesis. Here, we report on the activation of beta-catenin during early postnatal liver growth. Modulation of beta-catenin expression was studied in CD-1 mice livers over a time course of 0 to 30 postnatal days (PD) and 3 mo.

R-Etodolac decreases beta-catenin levels along with survival and proliferation of hepatoma cells.

Background/aims: Inhibition of hepatoma cells by cyclooxygenase (COX)-2-dependent and -independent mechanisms has been shown previously. Here, we examine the effect of Celecoxib, a COX-2-inhibitor and R-Etodolac, an enantiomer of the nonsteroidal anti-inflammatory drug Etodolac, which lacks COX-inhibitory activity, on the Wnt/beta-catenin pathway and human hepatoma cells.

Methods: Hep3B and HepG2 cell lines were treated with Celecoxib or R-Etodolac, and examined for viability, DNA synthesis, Wnt/beta-catenin pathway components, and downstream target gene expression.

Wnt'er in liver: expression of Wnt and frizzled genes in mouse.

Unlabelled: The Wnt signaling pathway is essential for a wide array of developmental and physiological processes. Wnts are extracellular ligands that bind to frizzled (Fz) receptors at the membrane, canonically inducing beta-catenin nuclear translocation and activation. Although beta-catenin has been shown to be critical in liver biology, the expression of the 19 Wnt and 10 Fz genes in liver remains undetermined.

Activation of Wnt/beta-catenin pathway during hepatocyte growth factor-induced hepatomegaly in mice.

Hepatocyte growth factor (HGF) and beta-catenin both play a crucial role in stimulating hepatocyte proliferation, but whether these 2 pathways cooperate in inducing hepatocyte proliferation is unclear. We have previously reported that beta-catenin forms a complex with c-Met (HGF receptor) that undergoes dissociation because of beta-catenin tyrosine phosphorylation on stimulation by HGF. It is also known that delivery of the human HGF gene cloned in a plasmid under a CMV promoter results in hepatomegaly in mice.

Mouse fetal liver cells in artificial capillary beds in three-dimensional four-compartment bioreactors.

Bioreactors containing porcine or adult human hepatocytes have been used to sustain acute liver failure patients until liver transplantation. However, prolonged function of adult hepatocytes has not been achieved due to compromised proliferation and viability of adult cells in vitro. We investigated the use of fetal hepatocytes as an alternative cell source in bioreactors.

Serum-free cryopreservation of porcine hepatocytes.

The use of porcine hepatocytes in xenotransplantation, bioartificial liver support or pharmacological approaches demands serum-free cryopreservation protocols yielding high quality, viable, functional hepatocytes. Here, primary porcine hepatocytes were frozen without serum in liquid nitrogen by the use of a computer-assisted freezing device. After thawing, more than 90% of the initial hepatocytes were lost, in part because of damage to genomic DNA.

Genotoxicological characterisation of complex mixtures. Genotoxic effects of a complex mixture of perhalogenated hydrocarbons.

Toxicological and genotoxicological investigation of complex mixtures is one of the main focus of the recent research in toxicology. Testing complex mixtures present a formidable scientific problem since most recently available toxicological data has been obtained from single substance studies and is not simply transferable to mixtures of chemicals. Although there are no special strategies and standard protocols available for determining toxic and genotoxic effects of complex mixtures, the fundamental concepts of evaluation are the same as those for single substances.