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

Abstract

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 up- and downregulation of hundreds of genes. An understanding of these changes is crucial for a correct interpretation of in vitro data. The possibilities and limitations of the most useful liver in vitro systems are summarized, including three-dimensional culture techniques, co-cultures with non-parenchymal cells, hepatospheres, precision cut liver slices and the isolated perfused liver. Also discussed is how closely hepatoma, stem cell and iPS cell–derived hepatocyte-like-cells resemble real hepatocytes. Finally, a summary is given of the state of the art of liver in vitro and mathematical modeling systems that are currently used in the pharmaceutical industry with an emphasis on drug metabolism, prediction of clearance, drug interaction, transporter studies and hepatotoxicity. One key message is that despite our enthusiasm for in vitro systems, we must never lose sight of the in vivo situation. Although hepatocytes have been isolated for decades, the hunt for relevant alternative systems has only just begun.Electronic supplementary materialThe online version of this article (doi:10.1007/s00204-013-1078-5) contains supplementary material, which is available to authorized users.

Highlight report: prediction of drug induced liver injury (DILI) with human hepatocytes in vitro

“…In recent years, much effort has been invested into the development of hepatocyte in vitro systems (Ehrhardt and Schmicke 2016;Ramboer et al 2015;Verhulst et al 2015;Hammad and Ahmed 2014;Hammad et al 2017;Godoy et al , 2015Grinberg et al 2014). Besides cytotoxicity further readouts, such as gene expression or functional endpoints have been recommended (Grinberg et al 2014;Reif et al 2015;Rashidi et al 2016;Arbo et al 2016).…”

Highlight report: perspectives in stem cell research—unbiased quantification of the similarity between in vitro generated and primary hepatocytes

“…In vitro systems represent a cutting-edge topic in toxicology (Grinberg et al 2014;Frey et al 2014;Godoy et al 2013;Godoy 2011;Stewart and Marchan 2014). Particularly, in the fields of liver (Godoy et al 2013;Zellmer et al 2010;Godoy and Bolt 2012), kidney (Faiz et al 2015;Yang et al 2014), and neurotoxicity (Zimmer et al 2014;Waldmann et al 2014;Krug et al 2013), in vitro systems are frequently used.…”

“…Particularly, in the fields of liver (Godoy et al 2013;Zellmer et al 2010;Godoy and Bolt 2012), kidney (Faiz et al 2015;Yang et al 2014), and neurotoxicity (Zimmer et al 2014;Waldmann et al 2014;Krug et al 2013), in vitro systems are frequently used. Primary human cells still represent a gold standard in toxicological research (Heise et al 2012;Ghallab 2013Ghallab , 2014a.…”

Highlight report: cytoprotective signaling in toxicology

“…A second field addressing the stress responses of cells exposed to chemicals is the upregulation of detoxifying or downregulation of activating metabolism (Godoy et al 2013;El-Sherbeni and El-Kadi 2014;Abdelhamid et al 2013;Grinberg et al 2014). Metabolism still represents one of the major challenges for in vitro system development (Hammad 2013;Reif 2014;Godoy 2010Godoy , 2011.…”