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.

• 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

Dietary and microbial indoles can act as ligands and activators of pregnane X receptor (PXR), with implications in human intestinal health. In the current study, we examined the effects of simple mono-methylated indoles (MMIs) on the activity and function of PXR, using a series of human hepatic and intestinal cell models. Indoles 1-MMI and 2-MMI strongly induced CYP3A4 and MDR1 mRNAs in human intestinal adenocarcinoma cells LS180, but not in primary human hepatocytes. The levels of CYP3A4 mRNA were increased by 1-MMI and 2-MMI in wild type, but not in PXR-knock-out human hepatic progenitor HepaRG cells, implying the involvement of PXR in CYP3A4 induction by MMIs. Utilizing reporter gene assay, we observed dose-dependent activation of PXR by all MMIs, and their efficacies and potencies were comparable. Tested MMIs also displayed moderate antagonist effects on PXR, revealing about partial agonist effects of these compounds. As demonstrated using the Chromatin immunoprecipitation assay (ChIP),1-MMI increased PXR occupancy of the CYP3A4 promoter. Time-Resolved Fluorescence Resonance Energy Transfer revealed that MMIs are weak ligands of human PXR. Collectively, we show that MMIs are ligands and partial agonists of human PXR, which induce PXR-regulated genes in human intestinal cells.

• MeSH
• cytochrom P-450 CYP3A genetika   fyziologie   MeSH
• hepatocyty účinky léků   metabolismus   MeSH
• indoly metabolismus   farmakologie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• P-glykoproteiny genetika   MeSH
• pregnanový X receptor účinky léků   genetika   metabolismus   MeSH
• promotorové oblasti (genetika) MeSH
• signální transdukce účinky léků   MeSH
• střevní sliznice cytologie   účinky léků   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Mono-methylindoles (MMI) were described as agonists and/or antagonists of the human aryl hydrocarbon receptor (AhR). Here, we investigated the effects of MMI on AhR-CYP1A pathway in human hepatocytes and HepaRG cells derived from human progenitor hepatic cells. All MMI, except of 2-methylindole, strongly induced CYP1A1 and CYP1A2 mRNAs in HepaRG cells. Induction of CYP1A genes was absent in AhR-knock-out HepaRG cells. Consistently, CYP1A1 and CYP1A2 mRNAs and proteins were induced by all MMIs (except 2-methylindole), in human hepatocytes. The enzyme activity of CYP1A1 was inhibited by MMIs in human hepatocytes and LS180 colon cancer cells in a concentration-dependent manner (IC50 values from 1.2 μM to 23.8 μM and from 3.4 μM to 11.4 μM, respectively). Inhibition of CYP1A1 activity by MMI in human liver microsomes was much weaker as compared to that in intact cells. Incubation of parental MMI with human hepatocytes either diminished (4-methylindole, 6-methylindole) or enhanced (7-methylindole) their agonist effects on AhR in AZ-AHR reporter cells. In conclusion, overall effects of MMI on AhR-CYP1A pathway in human cells comprise the induction of CYP1A genes through AhR, the inhibition of CYP1A catalytic activity and possibly the metabolic transformation causing loss or gain of AhR agonist activity of parental compounds.

• MeSH
• cytochrom P-450 CYP1A1 antagonisté a inhibitory   biosyntéza   genetika   MeSH
• enzymová indukce MeSH
• hepatocyty účinky léků   enzymologie   MeSH
• indoly farmakologie   MeSH
• induktory cytochromu P450 farmakologie   MeSH
• inhibitory cytochromu P450 farmakologie   MeSH
• jaterní mikrozomy účinky léků   enzymologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• nádorové buněčné linie MeSH
• nádory tračníku enzymologie   MeSH
• receptory aromatických uhlovodíků agonisté   genetika   metabolismus   MeSH
• senioři MeSH
• transkripční faktory bHLH agonisté   genetika   metabolismus   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Essential oils (EOs) of culinary herbs and spices are used to flavor, color and preserve foods and drinks. Dietary intake of EOs is significant, deserving an attention of toxicologists. We examined the effects of 31 EOs of culinary herbs and spices on the transcriptional activity of human aryl hydrocarbon receptor (AhR), which is a pivotal xenobiotic sensor, having also multiple roles in human physiology. Tested EOs were sorted out into AhR-inactive ones (14 EOs) and AhR-active ones, including full agonists (cumin, jasmine, vanilla, bay leaf), partial agonists (cloves, dill, thyme, nutmeg, oregano) and antagonists (tarragon, caraway, turmeric, lovage, fennel, spearmint, star anise, anise). Major constituents (>10%) of AhR-active EOs were studied in more detail. We identified AhR partial agonists (carvacrol, ligustilide, eugenol, eugenyl acetate, thymol, ar-turmerone) and antagonists (trans-anethole, butylidine phtalide, R/S-carvones, p-cymene), which account for AhR-mediated activities of EOs of fennel, anise, star anise, caraway, spearmint, tarragon, cloves, dill, turmeric, lovage, thyme and oregano. We also show that AhR-mediated effects of some individual constituents of EOs differ from those manifested in mixtures. In conclusion, EOs of culinary herbs and spices are agonists and antagonists of human AhR, implying a potential for food-drug interactions and interference with endocrine pathways.

• MeSH
• cytochrom P-450 CYP1A1 genetika   metabolismus   MeSH
• dobromysl (rod) MeSH
• interakce mezi potravou a léky MeSH
• koření analýza   MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• Myristica MeSH
• nádorové buněčné linie MeSH
• oleje prchavé farmakologie   MeSH
• oleje rostlin farmakologie   MeSH
• receptory aromatických uhlovodíků agonisté   antagonisté a inhibitory   MeSH
• regulace genové exprese účinky léků   MeSH
• Thymus (rostlina) MeSH
• transkripční faktory bHLH agonisté   antagonisté a inhibitory   MeSH
• vaření MeSH
• vavřín MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Essential oils (EOs) are extensively used in food industry, gastronomy and alternative medicine. They are multicomponent mixtures of bioactive compounds; hence, their potential for food-drug interactions is substantial. In this study, we investigated the effects of 31 EOs of culinary herbs and spices on the transcriptional activity of pregnane X receptor (PXR) and expression of cytochrome P450 3A4 (CYP3A4), using human intestinal and hepatic in vitro models. All tested EOs activated PXR in intestinal LS180 cells transiently transfected with PXR, as revealed by a reporter gene assay. Consistently, all EOs induced CYP3A4 mRNA expression in PXR-transfected LS180 cells, primary human hepatocytes and wild-type hepatic progenitor HepaRG cells. EO-mediated induction of CYP3A4 mRNA expression was nullified in PXR-knock out HepaRG cells, suggesting the involvement of PXR in these effects. Collectively, we showed that EOs of culinary herbs and spices might be common activators of PXR and inducers of CYP3A4 at doses present in foods, thereby, they might have a potential for food-drug interactions. Follow-up studies are warranted to identify the bioactive constituents in the tested EOs.

• MeSH
• aktivace transkripce účinky léků   MeSH
• buněčné linie MeSH
• cytochrom P-450 CYP3A biosyntéza   MeSH
• cytochrom P450 CYP2B6 biosyntéza   genetika   MeSH
• enzymová indukce účinky léků   MeSH
• hepatocyty účinky léků   MeSH
• játra účinky léků   metabolismus   MeSH
• koření analýza   MeSH
• lidé MeSH
• oleje prchavé farmakologie   MeSH
• P-glykoproteiny biosyntéza   MeSH
• primární buněčná kultura MeSH
• reportérové geny MeSH
• steroidní receptory účinky léků   metabolismus   MeSH
• střeva účinky léků   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Novel methylindoles were identified as endobiotic and xenobiotic ligands of the human aryl hydrocarbon receptor (AhR). We examined the effects of 22 methylated and methoxylated indoles on the transcriptional activity of AhRs. Employing reporter gene assays in AZ-AHR transgenic cells, we determined full agonist, partial agonist, or antagonist activities of tested compounds, having substantially variable EC50, IC50, and relative efficacies. The most effective agonists (EMAX relative to 5 nM dioxin) of the AhR were 4-Me-indole (134%), 6-Me-indole (91%), and 7-MeO-indole (80%), respectively. The most effective antagonists of the AhR included 3-Me-indole (IC50; 19 μM), 2,3-diMe-indole (IC50; 11 μM), and 2,3,7-triMe-indole (IC50; 12 μM). Reverse transcription polymerase chain reaction analyses of CYP1A1 mRNA in LS180 cells confirmed the data from gene reporter assays. The compound leads, 4-Me-indole and 7-MeO-indole, induced substantial nuclear translocation of the AhR and enriched binding of the AhR to the CYP1A1 promoter, as observed using fluorescent immunohistochemistry and chromatin immunoprecipitation assays, respectively. Molecular modeling and docking studies suggest the agonists and antagonists likely share the same binding pocket but have unique binding modes that code for their affinity. Binding pocket analysis further revealed that 4-methylindole and 7-methoxyindole can simultaneously bind to the pocket and produce synergistic interactions. Together, these data show a dependence on subtle and specific chemical indole structures as AhR modulators and furthermore underscore the importance of complete evaluation of indole compounds as nuclear receptor ligands.

• MeSH
• buňky Hep G2 MeSH
• cytochrom P-450 CYP1A1 metabolismus   MeSH
• indoly farmakologie   MeSH
• lidé MeSH
• ligandy MeSH
• messenger RNA metabolismus   MeSH
• nádorové buněčné linie MeSH
• promotorové oblasti (genetika) účinky léků   MeSH
• receptory aromatických uhlovodíků agonisté   antagonisté a inhibitory   MeSH
• reportérové geny účinky léků   MeSH
• transkripční faktory bHLH agonisté   antagonisté a inhibitory   MeSH
• Check Tag
• lidé 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

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.

• MeSH
• buněčné linie MeSH
• endokrinní disruptory metabolismus   toxicita   MeSH
• epitelové buňky účinky léků   MeSH
• hydroxylace MeSH
• látky znečišťující vzduch toxicita   MeSH
• lidé MeSH
• nádory metabolismus   MeSH
• polychlorované bifenyly metabolismus   toxicita   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

The role of vitamin D receptor (VDR) in immune responses has been broadly studied and it has been shown that activated VDR alters the levels of some interleukins (ILs). In this study, we studied the opposite, i.e. whether 13 selected pro-inflammatory and anti-inflammatory ILs influence the transcriptional activity of human VDR. The experimental models of choice were two human stably transfected gene reporter cell lines IZ-VDRE and IZ-CYP24, which were designed to evaluate the transcriptional activity of VDR. The gene reporter assays revealed inhibition of calcitriol-induced luciferase activity by IL-4 and IL-13, when 1 ng/mL of these two compounds decreased the effect of calcitriol down to 60% of the control value. Consistently, calcitriol-induced expression of CYP24A1 mRNA was also significantly decreased by IL-4 and IL-13. The expression of VDR and CYP27B1 mRNAs was not influenced by any of the 13 tested ILs. These data suggest possible cross-talk between the VDR signalling pathway and IL-4- and IL-13-mediated cell signalling.

• MeSH
• 1-alfa-hydroxylasa 25-hydroxyvitaminu D3 genetika   MeSH
• buněčné linie MeSH
• CYP24A1 genetika   MeSH
• genetická transkripce účinky léků   MeSH
• interleukiny farmakologie   MeSH
• lidé MeSH
• receptory kalcitriolu genetika   MeSH
• reportérové geny genetika   MeSH
• transfekce MeSH
• transgeny genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Essential oils (EOs) of culinary herbs and spices are consumed on a daily basis. They are multicomponent mixtures of compounds with already demonstrated biological activities. Taking into account regular dietary intake and the chemical composition of EOs, they may be considered as candidates for endocrine-disrupting entities. Therefore, we examined the effects of 31 EOs of culinary herbs and spices on transcriptional activities of glucocorticoid receptor (GR), androgen receptor (AR) and vitamin D receptor (VDR). Using reporter gene assays in stably transfected cell lines, weak anti-androgen and anti-glucocorticoid activity was observed for EO of vanilla and nutmeg, respectively. Moderate augmentation of calcitriol-dependent VDR activity was caused by EOs of ginger, thyme, coriander and lemongrass. Mixed anti-glucocorticoid and VDR-stimulatory activities were displayed by EOs of turmeric, oregano, dill, caraway, verveine and spearmint. The remaining 19 EOs were inactive against all receptors under investigation. Analyses of GR, AR and VDR target genes by means of RT-PCR confirmed the VDR-stimulatory effects, but could not confirm the anti-glucocorticoid and anti-androgen effects of EOs. In conclusion, although we observed minor effects of several EOs on transcriptional activities of GR, AR and VDR, the toxicological significance of these effects is very low. Hence, 31 EOs of culinary herbs and spices may be considered safe, in terms of endocrine disruption involving receptors GR, AR and VDR.

• MeSH
• aktivace transkripce účinky léků   MeSH
• androgenní receptory chemie   metabolismus   MeSH
• androgeny škodlivé účinky   MeSH
• antagonisté androgenů škodlivé účinky   MeSH
• endokrinní disruptory škodlivé účinky   MeSH
• jedlé rostliny chemie   MeSH
• koření * MeSH
• léčivé rostliny chemie   MeSH
• lidé MeSH
• ligandy MeSH
• nádorové buněčné linie MeSH
• oleje prchavé škodlivé účinky   MeSH
• receptory glukokortikoidů agonisté   antagonisté a inhibitory   genetika   metabolismus   MeSH
• receptory kalcitriolu agonisté   antagonisté a inhibitory   genetika   metabolismus   MeSH
• regulace genové exprese účinky léků   MeSH
• rekombinantní proteiny chemie   metabolismus   MeSH
• reportérové geny účinky léků   MeSH
• reprodukovatelnost výsledků MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Geografické názvy
• Česká republika MeSH

Variety of xenobiotics, including therapeutically used vitamin D analogues or environmental and alimentary endocrine disruptors, may interfere with vitamin D receptor (VDR) signaling, with serious physiological or pathophysiological consequences. Therefore, it is of topical interest to have reliable and efficient in vitro screening tools for the identification of agonists and activators of human VDR. We present here two novel stably transfected human reporter cell lines allowing rapid, high-throughput, and selective identification of VDR agonists and activators. Human colon adenocarcinoma cells LS180 were stably transfected with reporter plasmids CYP24_minP-pNL2.1[Nluc/Hygro] (IZ-CYP24 cells contain the -326/-46 sequence from the human CYP24A1 promoter) or VDREI3_SV40-pNL2.1[Nluc/Hygro] (IZ-VDRE cells contain three copies of vitamin D response elements VDRE-I from the human CYP24A1 promoter). Both cell lines remained fully functional for over two months in the culture and also after cryopreservation. Luciferase inductions ranged from 10-fold to 25-fold (RLU 10(6)-10(7)) and from 30-fold to 80-fold (RLU 10(3)-10(4)) in IZ-VDRE and IZ-CYP24 cells, respectively. Time-course analyses revealed that detection of VDR activators is possible as soon as after 8 h of incubation. Cell lines were highly selective toward VDR agonists, displaying no cross-activation by retinoids, thyroids, and steroids. As a proof of concept, we used IZ-VDRE and IZ-CYP24 cells for profiling analogues of vitamin D, and intermediates in vitamin D2 and vitamin D3 metabolic pathways against VDR transcriptional activity. The data obtained revealed significant activation of VDR not only by obligatory ligands calcitriol and ergocalcitriol but also by their precursors and degradation products.

• MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• receptory kalcitriolu metabolismus   MeSH
• reportérové geny * MeSH
• rodina 24 cytochromů P450 genetika   MeSH
• vitamin D metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH