Analysis of Glycogen Synthase Kinase Inhibitors That Regulate Cytochrome P450 Expression in Primary Human Hepatocytes by Activation of beta-Catenin, Aryl Hydrocarbon Receptor and Pregnane X Receptor Signaling

作者：Briolotti Philippe; Chaloin Laurent; Balaguer Patrick; Da Silva Franck; Tomankova Veronika; Pascussi Jean Marc; Duret Cedric; Fabre Jean Michel; Ramos Jeanne; Klieber Sylvie; Maurel Patrick; Daujat Chavanieu Martine; Gerbal Chaloin Sabine^*

来源：Toxicological Sciences, 2015, 148(1): 261-275.

DOI：10.1093/toxsci/kfv177

• GSK3 beta
• CYP
• CTNNB1
• AhR
• PXR
• crosstalk

Cytochrome P450 (CYP) expression and activity are not homogeneous in the liver lobules. Indeed, CYPs are mainly expressed and induced in centrilobular hepatocytes. The wingless-type MMTV integration site family (WNT)/beta-catenin pathway was identified as a major regulator of this zonal organization. We have recently demonstrated that in primary human hepatocytes (PHHs), the expression of CYP2E1, CYP1A2, and aryl hydrocarbon receptor (AhR), but not of CYP3A4, is regulated by the WNT/beta-catenin pathway in response to WNT3a, its canonical activator. Here, we investigated whether glycogen synthase kinase 3 beta (GSK3 beta) inhibitors, which mimic the action of WNT molecules, could be used in PHHs to activate the beta-catenin pathway to study CYP expression. We assessed the activity of 6BIO (6-bromoindirubin-3'-oxime), CHIR99021 (6-((2-((4-(2,4-dichlorophenyl)-5-(4methyl-1H-imidazol-2-yl)pyrimidin-2-yl)amino) ethyl)amino) nicotinonitrile), and GSK3iXV (Pyridocarbazolo-cyclopentadienyl Ruthenium complex GSK3 inhibitor XV) that belong to structurally different families of GSK3b inhibitors. Using small interfering RNAs, reporter gene assays, and molecular docking predictions, we demonstrated that GSK3 beta inhibitors can activate the WNT/beta-catenin pathway in PHHs to regulate CYP2E1 expression. We also found that 6BIO and GSK3iXV are AhR full agonists that participate, through AhR signaling, to CYP1A2 induction. Conversely, CHIR99021 is an AhR partial agonist, and a pregnane X receptor ligand and partial agonist, thus regulating CYP1A2 and CYP3A4 gene expression in a beta-catenin-independent manner. In conclusion, GSK3 beta inhibitors can activate the WNT/beta-catenin pathway in PHHs. Nevertheless, their role in CYP regulation should be analyzed with caution as these molecules can interact with xenosensors.

• 出版日期2015-11