A Systematic Comparison of the Impact of Inflammatory Signaling on Absorption, Distribution, Metabolism, and Excretion Gene Expression and Activity in Primary Human Hepatocytes and HepaRG Cells

Abstract

Inflammatory processes are associated with compromised metabolism and elimination of drugs in the liver, largely mediated by proinflammatory cytokines, such as interleukin-6. The Hepa-RG cell line is an established surrogate for primary human hepatocytes (PHH) in drug metabolism and toxicity studies. However, the impact of inflammatory signaling on HepaRG cells has not been well characterized. In this study, the response of primary human hepatocytes and HepaRG cells to interleukin (IL)-6 was comparatively analyzed. For this purpose, broad-spectrum gene expression profiling, including acute-phase response genes and a large panel of drug-metabolizing enzyme and transporter (DMET) genes as well as their modifiers and regulators, was conducted in combination with cytochrome P450 (P450) activity measurements. Exposure of PHH and HepaRG cells to IL-6 resulted in highly similar coordinated reduction of DMET mRNA, including major ATP-binding cassette transporters (ABCs), P450s, glutathione S-transferases (GSTs), uridine diphosphate glucuronosyltransferases (UGTs), and solute carriers (SLCs). Enzyme activities of CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, and CYP3A4 were reduced upon 48-72 hours exposure to IL-6 in PHH and HepaRG. However, although these effects were not significant in PHH due to large interindividual donor variability, the impact on HepaRG was more pronounced and highly significant, thus emphasizing the advantage of HepaRG as a more reproducible model system. Exposure of HepaRG cells to interleukin-1b and tumor necrosis factor a resulted in similar effects on gene expression and enzyme activities. The present study emphasizes the role of proinflammatory cytokines in the regulation of drug metabolism and supports the use of HepaRG in lieu of PHH to minimize subject variability.

Activating and Inhibitory Functions of WNT/β-Catenin in the Induction of Cytochromes P450 by Nuclear Receptors in HepaRG Cells

“…When following a differentiation protocol including two weeks of cultivation in medium containing a high amount of dimethylsulfoxide, HepaRG cells differentiate into a mixed population of hepatocyte-and bile duct epithelium-like cells. Differentiated HepaRG cells possess several hepatocyte-specific functions and show exceptional expression and activity of many P450s relevant for the metabolism of drugs and xenobiotics (Aninat et al, 2006;Guillouzo et al, 2007;Klein et al, 2015). Our data suggest a significant effect of WNT/ b-catenin signaling on basal as well as inducible expression of the major P450 genes.…”

“…The latter phenomenon has, to the best of our knowledge, not been previously analyzed in human cells. HepaRG cells were chosen because of their high relevance as an in vitro model for human hepatocytes, which show less interindividual variability compared with cultures of PHHs (Klein et al, 2015). By two different, complementary approaches for modulating the WNT pathway (namely by using the canonical ligand WNT3a as well as by specific siRNA-mediated b-catenin downregulation), our data provide evidence for an intricate crosstalk between the Role of b-Catenin in the Regulation of Human P450 Enzymes WNT/b-catenin pathway and various receptors involved in the regulation of P450 gene expression.…”

Involvement of Interleukin 6 in Hepatitis B Viral Infection

“…Sodium taurocholate cotransporting polypeptide (NTCP) is a multiple transmembrane transporter predominantly expressed in the liver [50], and is recognized as an HBV-specific receptor that binds to the N-terminal part of the pre-S1 region of the large envelope protein [51]. NTCP is known to be strongly downregulated by IL-6 [52]. Thus, IL-6 prevents HBV entry into cells through the downregulation of NTCP.…”

Inflammation-Associated MicroRNA-130b Down-Regulates Cytochrome P450 Activities and Directly Targets CYP2C9

“…This analysis revealed strongly elevated levels of miR-21, miR-34a, and miR-130b in cholestatic liver and of miR-21 and miR-130b during inflammation, as indicated by elevated C-reactive protein levels in the serum of the liver donors (Rieger et al, 2013). It is well known that during inflammatory conditions, cytokine signaling leads to a broad and effective down-regulation of ADME gene expression as well as P450 activities (Aitken et al, 2006;Klein et al, 2015). A number of studies have addressed potential mechanisms and hypotheses to explain the apparently coordinated response, although no single pathway could yet be elucidated that would be consistent with all experimental observations (Assenat et al, 2006 ;Morgan, 2009;Yang et al, 2010).…”