scholarly journals Antimigraine Drug Avitriptan Is a Ligand and Agonist of Human Aryl Hydrocarbon Receptor that Induces CYP1A1 in Hepatic and Intestinal Cells

2020 ◽  
Vol 21 (8) ◽  
pp. 2799
Author(s):  
Barbora Vyhlídalová ◽  
Kristýna Krasulová ◽  
Petra Pečinková ◽  
Karolína Poulíková ◽  
Radim Vrzal ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Nuclear Translocation ◽  
Primary Cultures ◽  
Human Colon ◽  
Human Hepatocytes ◽  
Intestinal Cells ◽  
Competitive Binding Assay ◽  
Aryl Hydrocarbon ◽  
Affinity Ligand ◽  
Cyp1a1 Mrna

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.

Dexamethasone controls aryl hydrocarbon receptor (AhR)-mediated CYP1A1 and CYP1A2 expression and activity in primary cultures of human hepatocytes

2009 ◽  
Vol 179 (2-3) ◽  
pp. 288-296 ◽  
Author(s):  
Radim Vrzal ◽  
Lucie Stejskalova ◽  
Katalin Monostory ◽  
Patrick Maurel ◽  
Petr Bachleda ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Primary Cultures ◽  
Human Hepatocytes ◽  
Aryl Hydrocarbon ◽  
Expression And Activity

scholarly journals Transporter Gene Regulation in Sandwich Cultured Human Hepatocytes Through the Activation of Constitutive Androstane Receptor (CAR) or Aryl Hydrocarbon Receptor (AhR)

2021 ◽  
Vol 11 ◽  
Author(s):  
Congrong Niu ◽  
Bill Smith ◽  
Yurong Lai
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Constitutive Androstane Receptor ◽  
Gene Induction ◽  
Human Hepatocytes ◽  
Drug Transporter ◽  
Transporter Gene ◽  
Aryl Hydrocarbon ◽  
Multiple Donors ◽  
Metabolizing Enzyme ◽  
Nuclear Receptor Ligands

The induction potentials of ligand-activated nuclear receptors on metabolizing enzyme genes are routinely tested for new chemical entities. However, regulations of drug transporter genes by the nuclear receptor ligands are underappreciated, especially in differentiated human hepatocyte cultures. In this study, gene induction by the ligands of constitutive androstane receptor (CAR) and aryl hydrocarbon receptor (AhR) was characterized in sandwich-cultured human hepatocytes (SCHH) from multiple donors. The cells were treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), omeprazole (OP), 6-(4-chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO) and phenobarbital (PB) for three days. RNA samples were analyzed by qRT-PCR method. As expected, CITCO, the direct activator, and PB, the indirect activator of CAR, induced CYP3A4 (31 and 40-fold), CYP2B6 (24 and 28-fold) and UGT1A1 (2.9 and 4.2-fold), respectively. Conversely, TCDD and OP, the activators of AhR, induced CYP1A1 (38 and 37-fold), and UGT1A1 (4.3 and 5.0-fold), respectively. In addition, OP but not TCDD induced CY3A4 by about 61-fold. Twenty-four hepatic drug transporter genes were characterized, and of those, SLC51B was induced the most by PB and OP by about 3.3 and 6.5 fold, respectively. Marginal inductions (about 2-fold) of SLC47A1 and SLCO4C1 genes by PB, and ABCG2 gene by TCDD were observed. In contrast, SLC10A1 gene was suppressed about 2-fold by TCDD and CITCO. While clinical relevance of SLC51B gene induction or SLC10A1 gene suppression warrants further investigation, the results verified that the assessment of transporter gene inductions are not required for new drug entities, when a drug does not remarkably induce metabolizing enzyme genes by CAR and AhR activation.

scholarly journals Tryptophan Metabolism Activates Aryl Hydrocarbon Receptor-Mediated Pathway To Promote HIV-1 Infection and Reactivation

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Yan-Heng Zhou ◽  
Li Sun ◽  
Jun Chen ◽  
Wei-Wei Sun ◽  
Li Ma ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Aryl Hydrocarbon Receptor ◽  
Metabolic Pathways ◽  
Nuclear Translocation ◽  
Underlying Mechanism ◽  
Hiv Pathogenesis ◽  
Downstream Target ◽  
Potential Target ◽  
Aryl Hydrocarbon ◽  
Hiv 1

ABSTRACT Multiple cellular metabolic pathways are altered by HIV-1 infection, with an impact on immune activation, inflammation, and acquisition of non-AIDS comorbid diseases. The dysfunction of tryptophan (Trp) metabolism has been observed clinically in association with accelerated HIV-1 pathogenesis, but the underlying mechanism remains unknown. In this study, we demonstrated that the aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, is activated by Trp metabolites to promote HIV-1 infection and reactivation. AHR directly binds to the HIV-1 5′ long terminal repeat (5′-LTR) at the molecular level to activate viral transcription and infection, and AHR activation by Trp metabolites increases its nuclear translocation and association with the HIV 5′-LTR; moreover, the binding of AHR with HIV-1 Tat facilitates the recruitment of positive transcription factors to viral promoters. These findings not only elucidate a previously unappreciated mechanism through which cellular Trp metabolites affect HIV pathogenesis but also suggest that a downstream target AHR may be a potential target for modulating HIV-1 infection. IMPORTANCE Cellular metabolic pathways that are altered by HIV-1 infection may accelerate disease progression. Dysfunction in tryptophan (Trp) metabolism has been observed clinically in association with accelerated HIV-1 pathogenesis, but the mechanism responsible was not known. This study demonstrates that Trp metabolites augment the activation of aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, to promote HIV-1 infection and transcription. These findings not only elucidate a previously unappreciated mechanism through which cellular Trp metabolites affect HIV pathogenesis but also suggest that a downstream target AHR may be a potential target for modulating HIV-1 infection.

JNK inhibitor SP600125 is a partial agonist of human aryl hydrocarbon receptor and induces CYP1A1 and CYP1A2 genes in primary human hepatocytes

2008 ◽  
Vol 75 (2) ◽  
pp. 580-588 ◽  
Author(s):  
Zdenek Dvorak ◽  
Radim Vrzal ◽  
Pavla Henklova ◽  
Petra Jancova ◽  
Eva Anzenbacherova ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Partial Agonist ◽  
Human Hepatocytes ◽  
Primary Human Hepatocytes ◽  
Aryl Hydrocarbon

scholarly journals Disruption of endogenous regulator homeostasis underlies the mechanism of rat CYP1A1 mRNA induction by metyrapone

1998 ◽  
Vol 331 (1) ◽  
pp. 273-281 ◽  
Author(s):  
Joanna L. HARVEY ◽  
Alan J. PAINE ◽  
Matthew C. WRIGHT
Keyword(s):  
Gene Expression ◽  
Glucocorticoid Receptor ◽  
Aryl Hydrocarbon Receptor ◽  
Culture Medium ◽  
Male Rats ◽  
Aryl Hydrocarbon ◽  
Mrna Induction ◽  
Cyp1a1 Gene ◽  
Cyp1a1 Mrna

The transcriptional induction of the cytochrome P-450 1A1 (CYP1A1) gene by xenobiotics such as polyaromatic hydrocarbons is dependent on their interaction with the aryl hydrocarbon receptor. Administration of the structurally unrelated compounds metyrapone (a cytochrome P-450 inhibitor) or dexamethasone (a glucocorticoid) to male rats does not induce hepatic CYP1A1 mRNA. However, administration of both metyrapone and dexamethasone to male rats results in the induction of hepatic CYP1A1 mRNA expression. The induction response is mimicked in vitro in cultured rat hepatocytes by the addition of metyrapone and dexamethasone to a serum-free culture medium, suggesting that these compounds act directly on the liver in vivo to effect hepatic CYP1A1 mRNA induction. An examination of the characteristics of CYP1A1 induction by metyrapone and dexamethasone in combination in vitro indicate that at least 6 h of treatment is required for detectable levels of CYP1A1 mRNA to accumulate in hepatocytes. In contrast, β-naphthoflavone, which is known to bind to the aryl hydrocarbon receptor to effect CYP1A1 gene expression, induces detectable levels of CYP1A1 mRNA within 2 h of treatment. CYP1A1 mRNA is also induced when hepatocytes are treated with metyrapone in combination with the protein synthesis inhibitor cycloheximide but not with dexamethasone in combination with cycloheximide, indicating that CYP1A1 mRNA induction is strictly dependent on the presence of metyrapone and suggesting that the metyrapone-associated induction of CYP1A1 mRNA is dependent on a loss of a constitutively expressed protein that functions to suppress CYP1A1 gene expression. The role of dexamethasone in metyrapone-associated induction of CYP1A1 is probably mediated through the glucocorticoid receptor since the glucocorticoid receptor antagonist RU486 reduces the levels of CYP1A1 mRNA induced by metyrapone and dexamethasone in combination. Increasing the levels of the photosensitizer riboflavin present in the culture medium 10-fold and exposure to light increases the levels of CYP1A1 mRNA induced by metyrapone and dexamethasone in combination in vitro, suggesting that photoactivation of inducing medium constituent(s) might be required for induction. Failure to induce CYP1A1 mRNA by co-administration of metyrapone and dexamethasone in hepatocytes cultured in a balanced salt solution with or without photoactivation indicates that induction is dependent on a photoactivated component of the culture medium and not on metyrapone or dexamethasone alone. The addition of tryptophan in the presence of riboflavin to the balanced salt solution restores CYP1A1 mRNA induction by metyrapone alone and induction is increased when medium is exposed to light, indicating that induction is dependent on tryptophan photoactivation in vitro. Metyrapone failed to compete with 2,3,7,8-tetrachlorodibenzo-p-dioxin for specific binding to the aryl hydrocarbon receptor in rat liver cytosolic fractions. These results suggest that CYP1A1 might be induced in rats by metyrapone through an indirect mechanism associated with an elevation in the level of an endogenously generated inducer such as photoactivated product(s) of tryptophan and not because of metyrapone's interacting with the aryl hydrocarbon receptor. The dependence of CYP1A1 induction on dexamethasone or cycloheximide suggests that derepression by a glucocorticoid receptor-modulated negative-acting factor of CYP1A1 gene expression might be critical to induction by metyrapone.

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