0000000000676735
AUTHOR
Elke Ueberham
Aryl hydrocarbon receptor-dependent cell cycle arrest in isolated mouse oval cells
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor, which mediates toxic responses to environmental pollutants, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds. Besides its well known role in induction of xenobiotic metabolizing enzymes, for instance CYP1A1, the AhR is also involved in tumor promotion in rodents although the underlying mechanisms are still poorly understood. Additionally, the AhR is known to regulate cellular proliferation, which might result in either inhibition or stimulation of proliferation depending on the cell-type studied. Potential targets in hepatocarcinogenesis are liver oval (stem/progenitor) cells. In the pres…
Hepatocyte-Specific Smad7 Expression Attenuates TGF-β–Mediated Fibrogenesis and Protects Against Liver Damage
Background & Aims The profibrogenic role of transforming growth factor (TGF)-β in liver has mostly been attributed to hepatic stellate cell activation and excess matrix synthesis. Hepatocytes are believed to contribute to increased rates of apoptosis. Methods Primary hepatocyte outgrowths and AML12 cells were used as an in vitro model to detect TGF-β effects on the cellular phenotype and expression profile. Furthermore, a transgenic mouse model was used to determine the outcome of hepatocyte-specific Smad7 expression on fibrogenesis following CCl 4 -dependent damage. Samples from patients with chronic liver diseases were assessed for (partial) epithelial-to-mesenchymal transition (EMT) in h…