The comparative effects of diethyldithiocarbamate-copper complex with established proteasome inhibitors on expression levels of CYP1A2/3A4 and their master regulators, aryl hydrocarbon and pregnane X receptor in primary cultures of human hepatocytes

2016 ◽  
Vol 30 (6) ◽  
pp. 585-595 ◽  
Author(s):  
Radim Vrzal ◽  
Zdenek Dvorak
2011 ◽  
Vol 31 (1) ◽  
pp. 86-93 ◽  
Author(s):  
Imen Ayed-Boussema ◽  
Jean-Marc Pascussi ◽  
Patrick Maurel ◽  
Hassen Bacha ◽  
Wafa Hassen

Aflatoxin B1 (AFB1), one of the most common mycotoxins found in human foods and animal feed, is principally hepatotoxic and hepatocarcinogenic. The aim of the present study was to explore the effect of AFB1 on messenger RNA (mRNA) expression of pregnane X receptor (PXR), constitutive androstane receptor (CAR), and aryl hydrocarbon receptor (AhR) and some of their target cytochromes using primary cultures of human hepatocytes. Our results showed that AFB1, at noncytotoxic increasing concentrations, caused a significant upregulation of cytochrome P 2B6 (CYP2B6), CYP3A5, and to a lesser extent CYP3A4 and CYP2C9. Pregnane X receptor and CAR mRNA expression increased in the 3 treated livers. Aflatoxin B1 was found also to induce an overexpression of CYP1A1 and CYP1A2 genes accompanied by an increase in AhR mRNA expression. These findings suggest that AFB1 could activate PXR, CAR, and AhR; however, further investigations are needed to confirm nuclear receptor activation by AFB1.


2020 ◽  
Vol 21 (8) ◽  
pp. 2799
Author(s):  
Barbora Vyhlídalová ◽  
Kristýna Krasulová ◽  
Petra Pečinková ◽  
Karolína Poulíková ◽  
Radim Vrzal ◽  
...  

The efforts for therapeutic targeting of the aryl hydrocarbon receptor (AhR) have emerged in recent years. We investigated the effects of available antimigraine triptan drugs, having an indole core in their structure, on AhR signaling in human hepatic and intestinal cells. Activation of AhR in reporter gene assays was observed for Avitriptan and to a lesser extent for Donitriptan, while other triptans were very weak or no activators of AhR. Using competitive binding assay and by homology docking, we identified Avitriptan as a low-affinity ligand of AhR. Avitriptan triggered nuclear translocation of AhR and increased binding of AhR in CYP1A1 promotor DNA, as revealed by immune-fluorescence microscopy and chromatin immune-precipitation assay, respectively. Strong induction of CYP1A1 mRNA was achieved by Avitriptan in wild type but not in AhR-knockout, immortalized human hepatocytes, implying that induction of CYP1A1 is AhR-dependent. Increased levels of CYP1A1 mRNA by Avitriptan were observed in human colon carcinoma cells LS180 but not in primary cultures of human hepatocytes. Collectively, we show that Avitriptan is a weak ligand and activator of human AhR, which induces the expression of CYP1A1 in a cell-type specific manner. Our data warrant the potential off-label therapeutic application of Avitriptan as an AhR-agonist drug.


2009 ◽  
Vol 179 (2-3) ◽  
pp. 288-296 ◽  
Author(s):  
Radim Vrzal ◽  
Lucie Stejskalova ◽  
Katalin Monostory ◽  
Patrick Maurel ◽  
Petr Bachleda ◽  
...  

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