0000000000583010
AUTHOR
Rolf Gebhardt
New Hepatocyte In Vitro Systems for Drug Metabolism: Metabolic Capacity and Recommendations for Application in Basic Research and Drug Development, Standard Operation Procedures
Primary hepatocytes represent a well-accepted in vitro cell culture system for studies of drug metabolism, enzyme induction, transplantation, viral hepatitis, and hepatocyte regeneration. Recently, a multicentric research program has been initiated to optimize and standardize new in vitro systems with hepatocytes. In this article, we discuss five of these in vitro systems: hepatocytes in suspension, perifusion culture systems, liver slices, co-culture systems of hepatocytes with intestinal bacteria, and 96-well plate bioreactors. From a technical point of view, freshly isolated or cryopreserved hepatocytes in suspension represent a readily available and easy-to-handle in vitro system that c…
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…
Recent advances in 2D and 3D in vitro systems using primary hepatocytes, alternative hepatocyte sources and non-parenchymal liver cells and their use in investigating mechanisms of hepatotoxicity, cell signaling and ADME.
This review encompasses the most important advances in liver functions and hepatotoxicity and analyzes which mechanisms can be studied in vitro. In a complex architecture of nested, zonated lobules, the liver consists of approximately 80 % hepatocytes and 20 % non-parenchymal cells, the latter being involved in a secondary phase that may dramatically aggravate the initial damage. Hepatotoxicity, as well as hepatic metabolism, is controlled by a set of nuclear receptors (including PXR, CAR, HNF-4α, FXR, LXR, SHP, VDR and PPAR) and signaling pathways. When isolating liver cells, some pathways are activated, e.g., the RAS/MEK/ERK pathway, whereas others are silenced (e.g. HNF-4α), resulting in…