Aryl hydrocarbon receptor (AHR) plays pivotal roles in intestinal physiology and pathophysiology. Intestinal AHR is activated by numerous dietary, endogenous, and microbial ligands. Whereas the effects of individual compounds on AHR are mostly known, the effects of real physiological mixtures occurring in the intestine have not been studied. Using reporter gene assays and RT-PCR, we evaluated the combinatorial effects (3520 combinations) of 11 microbial catabolites of tryptophan (MICTs) on AHR. We robustly (n = 30) determined the potencies and relative efficacies of single MICTs. Synergistic effects of MICT binary mixtures were observed between low- or medium-efficacy agonists, in particular for combinations of indole-3-propionate and indole-3-lactate. Combinations comprising highly efficacious agonists such as indole-3-pyruvate displayed rather antagonist effects, caused by saturation of the assay response. These synergistic effects were confirmed by RT-PCR as CYP1A1 mRNA expression. We also tested mimic multicomponent and binary mixtures of MICTs, prepared based on the metabolomic analyses of human feces and colonoscopy aspirates, respectively. In this case, AHR responsiveness did not correlate with type of diet or health status, and the indole concentrations in the mixtures were determinative of gross AHR activity. Future systematic research on the synergistic activation of AHR by microbial metabolites and other ligands is needed.

• Klíčová slova
• aryl hydrocarbon receptor, indole derivatives, microbiome, mimic mixtures, tryptophan metabolites,
• MeSH
• cytochrom P-450 CYP1A1 genetika   metabolismus   MeSH
• indoly metabolismus   farmakologie   MeSH
• lidé MeSH
• ligandy MeSH
• messenger RNA metabolismus   MeSH
• propionáty MeSH
• pyruváty MeSH
• receptory aromatických uhlovodíků * metabolismus   MeSH
• střeva MeSH
• tryptofan * metabolismus   farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cytochrom P-450 CYP1A1 MeSH
• indoly MeSH
• ligandy MeSH
• messenger RNA MeSH
• propionáty MeSH
• pyruváty MeSH
• receptory aromatických uhlovodíků * MeSH
• tryptofan * MeSH

The human PXR (pregnane X receptor), a master regulator of drug metabolism, has essential roles in intestinal homeostasis and abrogating inflammation. Existing PXR ligands have substantial off-target toxicity. Based on prior work that established microbial (indole) metabolites as PXR ligands, we proposed microbial metabolite mimicry as a novel strategy for drug discovery that allows exploiting previously unexplored parts of chemical space. Here, we report functionalized indole derivatives as first-in-class non-cytotoxic PXR agonists as a proof of concept for microbial metabolite mimicry. The lead compound, FKK6 (Felix Kopp Kortagere 6), binds directly to PXR protein in solution, induces PXR-specific target gene expression in cells, human organoids, and mice. FKK6 significantly represses pro-inflammatory cytokine production cells and abrogates inflammation in mice expressing the human PXR gene. The development of FKK6 demonstrates for the first time that microbial metabolite mimicry is a viable strategy for drug discovery and opens the door to underexploited regions of chemical space.

• Klíčová slova
• drugs, microbial metabolite, mimics, pregnane X receptor, therapy,
• MeSH
• cytokiny MeSH
• kultivované buňky MeSH
• lidé MeSH
• ligandy MeSH
• molekulární mimikry * MeSH
• myši MeSH
• organoidy MeSH
• pregnanový X receptor chemie   MeSH
• střeva MeSH
• zánět MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• cytokiny MeSH
• ligandy MeSH
• pregnanový X receptor MeSH

The mechanisms contributing to toxic effects of airborne lower-chlorinated PCB congeners (LC-PCBs) remain poorly characterized. We evaluated in vitro toxicities of environmental LC-PCBs found in both indoor and outdoor air (PCB 4, 8, 11, 18, 28 and 31), and selected hydroxylated metabolites of PCB 8, 11 and 18, using reporter gene assays, as well as other functional cellular bioassays. We focused on processes linked with endocrine disruption, tumor promotion and/or regulation of transcription factors controlling metabolism of both endogenous compounds and xenobiotics. The tested LC-PCBs were found to be mostly efficient anti-androgenic (within nanomolar - micromolar range) and estrogenic (at micromolar concentrations) compounds, as well as inhibitors of gap junctional intercellular communication (GJIC) at micromolar concentrations. PCB 8, 28 and 31 were found to partially inhibit the aryl hydrocarbon receptor (AhR)-mediated activity. The tested LC-PCBs were also partial constitutive androstane receptor (CAR) and pregnane X receptor (PXR) agonists, with PCB 4, 8 and 18 being the most active compounds. They were inactive towards other nuclear receptors, such as vitamin D receptor, thyroid receptor α, glucocorticoid receptor or peroxisome proliferator-activated receptor γ. We found that only PCB 8 contributed to generation of oxidative stress, while all tested LC-PCBs induced arachidonic acid release (albeit without further modulations of arachidonic acid metabolism) in human lung epithelial cells. Importantly, estrogenic effects of hydroxylated (OH-PCB) metabolites of LC-PCBs (4-OH-PCB 8, 4-OH-PCB 11 and 4'-OH-PCB 18) were higher than those of the parent PCBs, while their other toxic effects were only slightly altered or suppressed. This suggested that metabolism may alter toxicity profiles of LC-PCBs in a receptor-specific manner. In summary, anti-androgenic and estrogenic activities, acute inhibition of GJIC and suppression of the AhR-mediated activity were found to be the most relevant modes of action of airborne LC-PCBs, although they partially affected also additional cellular targets.

• Klíčová slova
• Airborne polychlorinated biphenyls, Endocrine disruption, HydroxyLated PCBs, Metabolism of xenobiotics, Tumor promotion,
• MeSH
• buněčné linie MeSH
• endokrinní disruptory metabolismus   toxicita   MeSH
• epitelové buňky účinky léků   MeSH
• hydroxylace MeSH
• konstitutivní androstanový receptor MeSH
• látky znečišťující vzduch toxicita   MeSH
• lidé MeSH
• nádory metabolismus   MeSH
• polychlorované bifenyly metabolismus   toxicita   MeSH
• pregnanový X receptor MeSH
• receptory cytoplazmatické a nukleární metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• steroidní receptory metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• endokrinní disruptory MeSH
• konstitutivní androstanový receptor MeSH
• látky znečišťující vzduch MeSH
• polychlorované bifenyly MeSH
• pregnanový X receptor MeSH
• receptory cytoplazmatické a nukleární MeSH
• steroidní receptory MeSH

Atorvastatin, fluvastatin and rosuvastatin are drugs used for treatment of hypercholesterolemia. They cause numerous drug-drug interactions by inhibiting and inducing drug-metabolizing cytochromes P450. These three statins exist in four optical forms, but they are currently used as enantiopure drugs, i.e., only one single enantiomer. There are numerous evidences that efficacy, adverse effects and toxicity of drugs may be enantiospecific. Therefore, we investigated the effects of optical isomers of atorvastatin, fluvastatin and rosuvastatin on the expression of drug-metabolizing P450s in primary human hepatocytes, using western blots and RT-PCR for measurement of proteins and mRNAs, respectively. The activity of P450 transcriptional regulators, including pregnane X receptor (PXR), aryl hydrocarbon receptor (AhR) and glucocorticoid receptor (GR), was assessed by gene reporter assays and EMSA. Transcriptional activity of AhR was not influenced by any statin tested. Basal transcriptional activity of GR was not affected by tested statins, but dexamethasone-inducible activity of GR was dose-dependently and enantioselectively inhibited by fluvastatin. Basal and ligand-inducible transcriptional activity of PXR was dose-dependently influenced by all tested statins, and the potency and efficacy between individual optical isomers varied depending on statin and optical isomer. The expression of CYP1A1 and CYP1A2 in human hepatocytes was not influenced by tested statins. All statins induced CYP2A6, CYP2B6 and CYP3A4, and the effects on CYP2C9 were rather modulatory. The effects varied between statins and enantiomers and induction potency decreased in order: atorvastatin (RR>RS = SR>SS) > fluvastatin (SR>RS = SS>RR) >> rosuvastatin (only RS active). The data presented here might be of toxicological and clinical importance.

• MeSH
• atorvastatin farmakologie   MeSH
• cytochrom P-450 CYP3A biosyntéza   MeSH
• cytochrom P450 CYP2A6 biosyntéza   MeSH
• cytochrom P450 CYP2B6 biosyntéza   MeSH
• dospělí MeSH
• enzymová indukce účinky léků   MeSH
• fluvastatin MeSH
• hepatocyty cytologie   enzymologie   MeSH
• indoly farmakologie   MeSH
• induktory cytochromu P450 CYP2B6 farmakologie   MeSH
• induktory cytochromu P450 CYP3A farmakologie   MeSH
• kyseliny mastné mononenasycené farmakologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• pregnanový X receptor MeSH
• rosuvastatin kalcium farmakologie   MeSH
• senioři MeSH
• stereoizomerie MeSH
• steroidní receptory biosyntéza   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• atorvastatin MeSH
• CYP2A6 protein, human MeSH Prohlížeč
• CYP2B6 protein, human MeSH Prohlížeč
• CYP3A4 protein, human MeSH Prohlížeč
• cytochrom P-450 CYP3A MeSH
• cytochrom P450 CYP2A6 MeSH
• cytochrom P450 CYP2B6 MeSH
• fluvastatin MeSH
• indoly MeSH
• induktory cytochromu P450 CYP2B6 MeSH
• induktory cytochromu P450 CYP3A MeSH
• kyseliny mastné mononenasycené MeSH
• pregnanový X receptor MeSH
• rosuvastatin kalcium MeSH
• steroidní receptory MeSH

Benzimidazole drugs lansoprazole and omeprazole are used for treatment of various gastrointestinal pathologies. Both compounds cause drug-drug interactions because they activate aryl hydrocarbon receptor and induce CYP1A genes. In the current paper, we examined the effects of lansoprazole and omeprazole enantiomers on the expression of key drug-metabolizing enzyme CYP3A4 in human hepatocytes and human cancer cell lines. Lansoprazole enantiomers, but not omeprazole, were equipotent inducers of CYP3A4 mRNA in HepG2 cells. All forms (S-, R-, rac-) of lansoprazole and omeprazole induced CYP3A4 mRNA and protein in human hepatocytes. The quantitative profiles of CYP3A4 induction by individual forms of lansoprazole and omeprazole exerted enantiospecific patterns. Lansoprazole dose-dependently activated pregnane X receptor PXR in gene reporter assays, and slightly modulated rifampicin-inducible PXR activity, with similar potency for each enantiomer. Omeprazole dose-dependently activated PXR and inhibited rifampicin-inducible PXR activity. The effects of S-omeprazole were much stronger as compared to those of R-omeprazole. All forms of lansoprazole, but not omeprazole, slightly activated glucocorticoid receptor and augmented dexamethasone-induced GR transcriptional activity. Omeprazole and lansoprazole influenced basal and ligand inducible expression of tyrosine aminotransferase, a GR-target gene, in HepG2 cells and human hepatocytes. Overall, we demonstrate here that omeprazole and lansoprazole enantiomers induce CYP3A4 in HepG2 cells and human hepatocytes. The induction comprises differential interactions of omeprazole and lansoprazole with transcriptional regulators PXR and GR, and some of the effects were enantiospecific. The data presented here might be of toxicological and clinical importance, since the effects occurred in therapeutically relevant concentrations.

• MeSH
• buňky Hep G2 MeSH
• cytochrom P-450 CYP3A genetika   metabolismus   MeSH
• hepatocyty účinky léků   metabolismus   MeSH
• kultivované buňky MeSH
• lanzoprazol škodlivé účinky   farmakologie   MeSH
• lidé MeSH
• omeprazol škodlivé účinky   farmakologie   MeSH
• pregnanový X receptor MeSH
• protivředové látky škodlivé účinky   farmakologie   MeSH
• receptory glukokortikoidů metabolismus   MeSH
• steroidní receptory metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• CYP3A4 protein, human MeSH Prohlížeč
• cytochrom P-450 CYP3A MeSH
• lanzoprazol MeSH
• omeprazol MeSH
• pregnanový X receptor MeSH
• protivředové látky MeSH
• receptory glukokortikoidů MeSH
• steroidní receptory MeSH

Azole antifungal ketoconazole (KET) was demonstrated to activate aryl hydrocarbon receptor (AhR). Since clinically used KET is a racemic mixture of two cis-enantiomers (2R,4S)-(+)-KET and (2S,4R)-(-)-KET, we examined the effects of KET enantiomers on AhR signaling pathway. (+)-KET dose-dependently activated AhR in human gene reporter cell line AZ-AHR, and displayed 5-20× higher agonist activity (efficacy), as compared to (-)-KET; both enantiomers were AhR antagonists with equal potency (IC50). Consistently, (+)-KET strongly induced CYP1A1 mRNA and protein in human HepG2 cells, while (-)-KET exerted less than 10% of (+)-KET activity. In primary human hepatocytes, both enantiomers preferentially induced CYP1A2 over CYP1A1 mRNA and protein, and the potency of (+)-KET was slightly higher as compared to (-)-KET. Ligand binding assay with guinea pig liver cytosols revealed that both (+)-KET and (-)-KET are weak ligands of AhR that displaced [3H]-TCDD with comparable potency. Similarly, both enantiomers weakly transformed AhR to DNA-binding form with similar potency, as showed by EMSA, in guinea pig liver cytosolic extracts and nuclear extracts from mouse Hepa-1 cells. We also examined effects of KET on glucocorticoid receptor (GR), a regulator of AhR activity. Both KET enantiomers antagonized GR with similar potency, as revealed by gene reporter assay in AZ-GR cell line and down-regulation of tyrosine aminotransferase mRNA in human hepatocytes. Finally, we demonstrate enantiospecific antifungal activities of KET enantiomers in six Candida spp. strains. In conclusion, the significance of current study is providing the first evidence of enatiospecific effects of cis-enantiomers of ketoconazole on AhR-CYP1A pathway.

• MeSH
• antifungální látky chemie   farmakologie   MeSH
• buňky Hep G2 MeSH
• Candida účinky léků   MeSH
• cytochrom P-450 CYP1A1 genetika   metabolismus   MeSH
• cytochrom P-450 CYP1A2 genetika   metabolismus   MeSH
• genetická transkripce účinky léků   MeSH
• hepatocyty účinky léků   metabolismus   MeSH
• ketokonazol chemie   farmakologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• morčata MeSH
• myši MeSH
• receptory aromatických uhlovodíků metabolismus   MeSH
• senioři MeSH
• signální transdukce účinky léků   MeSH
• stereoizomerie MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• morčata MeSH
• mužské pohlaví MeSH
• myši MeSH
• senioři MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• antifungální látky MeSH
• cytochrom P-450 CYP1A1 MeSH
• cytochrom P-450 CYP1A2 MeSH
• ketokonazol MeSH
• messenger RNA MeSH
• receptory aromatických uhlovodíků MeSH