Cyanobacterial blooms are increasing in frequency and intensity globally, and impacting recreational waters as well as waters used for drinking water provisioning. They are sources of bioactive metabolites including retinoids and the neurotoxin anatoxin-a. Here, we investigated the effects of anatoxin-a on a differentiating in vitro human neural stem cell model previously characterised with retinoic acids. Effects on protein and gene expression upon exposure for 9 or 18 days to anatoxin-a alone or in co-exposure with all-trans retinoic acid were evaluated using a panel of neural and glial differentiation biomarkers. Anatoxin-a did not cause distinct developmental neurotoxicity alone, or in co-exposure with retinoic acid. However, in line with its excitotoxicity, in co-exposure with 200 nM all-trans retinoic acid it reduced the differentiation of acetylcholinergic neuron subtypes in the culture at 1000 nM (highest tested concentration). While this could have substantial functional implications for the developing nervous system, there is no indication for developmental neurotoxicity beyond its (excito-)toxicity to acetylcholinergic neurons, which only occurred in co-exposure to all-trans retinoic acid.
- MeSH
- exprese genu MeSH
- lidé MeSH
- neurotoxické syndromy * etiologie MeSH
- retinoidy metabolismus MeSH
- sinice * MeSH
- toxiny kmene Cyanobacteria MeSH
- tretinoin toxicita MeSH
- tropany * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Microbial indoles have been demonstrated as selective or dual agonists and ligands of the pregnane X receptor (PXR) and aryl hydrocarbon receptor (AhR). However, structural determinants of microbial indoles selectivity towards both receptors remain elusive. Here, we studied the effects of existing and newly synthesized derivatives of indole microbial metabolite tryptamine on the activity of AhR and PXR receptors. We show that the elongation of indolyl-3-alkaneamine chain, indole N-methylation and conversion of indolyl-3-alkaneamines to oleamides resulted in a major increase of PXR activity and in parallel loss of AhR activity. Using reporter gene assays, RT-PCR and TR-FRET techniques, we have characterized in detail the activation of PXR by novel indolyl-3-alkanyl-oleamides, 1-methyltryptamine and 1-methyltryptamine-acetamide. As a proof of concept, we demonstrated anti-inflammatory and epithelial barrier-protective activity of lead derivatives in intestinal Caco-2 cells, employing the measurement of expression of pro-inflammatory chemokines, tight junction genes, trans-epithelial electric resistance TEER, and dextran-FITC permeability assay. In conclusion, we show that a subtle chemical modifications of simple microbial indole metabolite tryptamine, leads to substantial changes in AhR and PXR agonist activities.
Mitochondrial enzymes are targets of newly synthesized drugs being tested for the treatment of neurodegenerative disorders, such as Alzheimer's disease (AD). The enzyme 17β-hydroxysteroid dehydrogenase type 10 (HSD10) is a multifunctional mitochondrial protein that is thought to play a role in the pathophysiology of AD and is one of the targets of new potential AD drugs. The in vitro effects of frentizole, riluzole, AG18051, and 42 novel modulators of HSD10 (potential AD drugs) on citrate synthase (CS) activity, monoamine oxidase (MAO) activity, complex I- or complex II-linked mitochondrial respiratory rate, and complex I activity were measured in isolated pig brain mitochondria. Based on their minimal inhibitory effects on the respiratory rate of mitochondria and CS and complex I activity, six novel compounds were selected for further testing. Assuming that inhibition of MAO-B could be a desirable effect of AD drugs, only AG18051 and one new compound met the criteria for MAO-B inhibition with minimal drug-induced effects on mitochondrial respiration. In conclusion, our in vitro screening of mitochondrial effect of novel potential AD drugs has enabled the selection of the most promising molecules for further testing that are relatively safe in terms of drug-induced mitochondrial toxicity.
- MeSH
- 17-hydroxysteroidní dehydrogenasy antagonisté a inhibitory toxicita MeSH
- buněčné dýchání účinky léků MeSH
- inhibitory enzymů terapeutické užití toxicita MeSH
- lidé MeSH
- mitochondrie účinky léků MeSH
- modely u zvířat MeSH
- neurodegenerativní nemoci farmakoterapie MeSH
- prasata MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Remdesivir (RDV) is a novel antiviral drug whose mitochondrial effects are not well known. In vitro effects of RDV on the mitochondrial respiration, individual respiratory complexes, and the activity of monoamine oxidase (MAO-A and MAO-B) were measured in isolated mitochondria. At micromolar RDV concentrations, minimal or no inhibitory effects on the studied mitochondrial enzymes were found. At very high concentrations of RDV, there was partial inhibition of complex I- (IC50 675 μmol/L, residual activity 39.4 %) and complex II-linked (IC50 81.8 μmol/L, residual activity 40.7 %) respiration, without inhibition of complex IV-linked respiration, and partial inhibition both of MAO-A (IC50 26.6 μmol/L, residual activity 35.2 %) and MAO-B (IC50 89.8 μmol/L, residual activity 34.0 %) activity. Individual respiratory complexes (I, II + III, and IV) were partially inhibited at a high drug concentration. The active metabolite of RDV (GS-443902) had very little effect on mitochondrial oxygen consumption rate with residual activity of 87.0 % for complex I-linked respiration, 90.3 % for complex II-linked respiration, and with no inhibition of complex IV-linked respiration. In conclusion, measurement of the effect of RDV and its active metabolite on isolated mitochondria shows that there is very little direct effect on mitochondrial respiration occurs at therapeutic drug concentration.
- MeSH
- antivirové látky farmakologie MeSH
- buněčné dýchání účinky léků MeSH
- kultivované buňky účinky léků MeSH
- lidé MeSH
- mitochondrie účinky léků metabolismus MeSH
- modely u zvířat MeSH
- monoaminoxidasa účinky léků metabolismus MeSH
- prasata MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Concentration addition as a classic null model for toxicology and pharmacology is based on Loewe's mathematical formulation and the linearity of the isoboles. Novel mathematical models, however, propose curved isoboles in certain conditions. This article aims to test the hypothesis of the curvature of isoboles in experimental measurements. With the assumption of linear isoboles, a partial agonist acts as an antagonist above its maximal effect level. The isoboles automatically convert to a positive slope. For curved isoboles, a partial agonist acts as an antagonist at higher effect levels than its maximal effect alone. The discrepancies between effect levels were studied with an estrogen receptor binding assay (BMAEREluc/ERα) using a mixture of 17β-estradiol and fulvestrant as a partial agonist. A mixture of 17β-estradiol and fulvestrant acts as a partial agonist and causes the diminishing of the effect level of 17β-estradiol at a significantly higher level than the maximal effect of their partial-agonistic dose-response curve. Measured, elevated effect levels were well predicted by the mathematical model. Nonlinear isoboles may change our understanding and definition of synergism or antagonism and prompt further attention in receptor theory.
BACKGROUND: From 2012 to 2013, there was a mass methanol poisoning outbreak in the Czech Republic. Methanol metabolites can cause specific lesions in the basal ganglia, subcortical white matter, and optic nerve. However, long-term sequelae of methanol poisoning on cognitive functioning have not yet been explored. The current study aimed to delineate the cognitive changes observed in methanol poisoning survivors in the seven years since 2012. METHODS: We conducted longitudinal research with repeated measurements in 2013, 2015, 2017 and 2019 to evaluate the development of cognitive changes after acute methanol poisoning. A complex neuropsychological battery consisted of tests of global cognitive performance, auditory and visual attention, executive functioning, learning and memory, working memory and language. Motor performance measures and depression scale were also included. RESULTS: Repeated measures ANOVA of four measurements with post-hoc tests showed a significant decline in the Mini-Mental State Examination (p = 0.007); however, other parameters were not significantly decreasing. In comparison to normative values, the z-scores for each test measure, in the memory domain, in particular, ranged from 43 to 60 % of participants below 1.5 SD. Mild to severe depression levels from the onset of poisoning improved during the seven years, returning to normal in up to 27 % of participants. CONCLUSION: In the longitudinal perspective, methanol poisoning survivors manifest progressive global cognitive decline and overall persistent below-average cognitive performance with some improvements in the frequency of depressive symptoms.
- MeSH
- časové faktory MeSH
- deprese chemicky indukované diagnóza epidemiologie psychologie MeSH
- dospělí MeSH
- epizodická paměť * MeSH
- kognice účinky léků MeSH
- kognitivní dysfunkce chemicky indukované diagnóza epidemiologie psychologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- longitudinální studie MeSH
- methanol otrava MeSH
- mladý dospělý MeSH
- neuropsychologické testy MeSH
- neurotoxické syndromy diagnóza epidemiologie psychologie MeSH
- poruchy paměti chemicky indukované diagnóza epidemiologie psychologie MeSH
- prevalence MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Piscine cytochrome P450 (CYP) enzymes play an important role in the metabolism of xenobiotics. Xenobiotics often act as inducers of CYP1A1 and CYP3A expression and activity in fish. We compared constitutive mRNA expression of CYP1A1, CYP3A27, and CYP3A45 and catalytic activity of CYP1A (7-ethoxyresorufin-O-deethylation, EROD) and CYP3A-like (benzyloxy-4-trifluoromethylcoumarin-O-debenzyloxylation, BFCOD) enzymes in the following six rainbow trout tissues: liver, gill, heart, brain, intestine, and gonad. mRNA expression and activity were present in all investigated tissues. The CYP1A1 mRNA expression was higher in the liver, gill, heart, and brain compared to gonad and intestine. The intestine was the main site of CYP3A27 and CYP3A45 expression. The highest EROD and BFCOD activity was observed in liver tissue followed in descending order by heart, brain, gill, intestine, and gonad. Such differences might be related to the role of CYP physiological functions in the specific tissue. Rainbow trout exposure to 50 mg/kg of β-naphthoflavone for 48 h resulted in a 7.5- and 5.9-fold increase in liver EROD and BFCOD activity, respectively. In vitro EROD activity inhibition with ellipticine showed tissue-specific inhibition, while ketoconazole decreased BFCOD activity by 50-98 % in all tissues. Further studies are needed to identify all CYP isoforms that are responsible for these activities and modes of regulation.
- MeSH
- cytochrom P-450 CYP1A1 genetika metabolismus MeSH
- cytochrom P-450 CYP3A genetika metabolismus MeSH
- játra enzymologie MeSH
- messenger RNA genetika metabolismus MeSH
- mozek enzymologie MeSH
- myokard enzymologie MeSH
- Oncorhynchus mykiss metabolismus MeSH
- pohlavní dimorfismus MeSH
- regulace genové exprese enzymů fyziologie MeSH
- střeva enzymologie MeSH
- žábry enzymologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Oxime-based acetylcholinesterase reactivators (briefly oximes) regenerate organophosphate-inactivated acetylcholinesterase and restore its function. Poor blood-brain-barrier passage and fast elimination from blood limit their actual use in treatment of patients exposed to organophosphates. Previous in vitro results implicated further testing of cucurbit[7]uril as a delivery vehicle for bisquaternary oximes. The present paper focuses on cell toxicity, in vivo safety and influence of cucurbit[7]uril on oxime pharmacokinetics and pharmacodynamics. Neither the K027 nor the complex caused any cell toxicity, changes in blood biochemistry or hepato- or nephrotoxicity in tested concentrations. The encapsulation of K027 increased and accelerated the blood-brain-barrier penetration. The peripheral oxime exposure also increased, supporting the suggestion that cucurbit[7]uril protects the circulating oxime from rapid renal clearance. Contrary to the comparable in vitro reactivation power of K027 and the encapsulated K027, we failed to confirm this in vivo. In theory, this might result from the non-specific binding of molecules to the cucurbit[7]uril or the interaction of K027 with cucurbit[7]uril being too strong for acetylcholinesterase reactivation. Precise explanation requires additional in silico, in vitro and also in vivo experiments.
- MeSH
- acetylcholinesterasa krev metabolismus MeSH
- buňky A549 MeSH
- buňky Hep G2 MeSH
- erytrocyty účinky léků enzymologie MeSH
- GPI-vázané proteiny krev metabolismus MeSH
- hodnocení rizik MeSH
- imidazoly aplikace a dávkování farmakokinetika toxicita MeSH
- injekce intramuskulární MeSH
- lidé MeSH
- maximální tolerovaná dávka MeSH
- mozek účinky léků enzymologie MeSH
- myši inbrední ICR MeSH
- oximy aplikace a dávkování farmakokinetika toxicita MeSH
- přemostěné cyklické sloučeniny aplikace a dávkování farmakokinetika toxicita MeSH
- pyridinové sloučeniny aplikace a dávkování farmakokinetika toxicita MeSH
- reaktivátory cholinesterázy aplikace a dávkování farmakokinetika toxicita MeSH
- tkáňová distribuce MeSH
- viabilita buněk účinky léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
An attempt has been made to delineate the role of natural and synthetic retinoid receptor ligands on vimentin expression in the human triple-negative breast cancer cells. The effects of currently synthesized triorganotin derivatives of the general formula R3SnX (R is butyl or phenyl, X is isothiocyanate), which are considered RXR ligands, were investigated in the human MDA-MB-231 breast cancer cell line. Studies were evaluated in the presence and absence of all-trans retinoic acid (ATRA), a natural RAR ligand. Vimentin represents the major protein associated with epithelial-mesenchymal transition (EMT), an essential process when the primary tumour transforms into a malignant one. mRNA and proteomic data obtained in this study, based on the PDQuest software protein evaluation and further quantification of proteins by iTRAQ analysis, suggest that vimentin was significantly reduced in the combination of RAR ligand and RXR ligand treatment. Both tested triorganotin compounds showed similarly reduced expression of vimentin, but tributyltin isothiocyanate (TBT-ITC) proved to be more effective than triphenyltin isothiocyanate (TPT-ITC). Furthermore, the effect of natural (9cRA) and synthetic RXR ligands, both chloride and isothiocyanate derivatives, on vimentin expression was compared.
- MeSH
- 2D gelová elektroforéza MeSH
- antitumorózní látky farmakologie MeSH
- down regulace MeSH
- epitelo-mezenchymální tranzice účinky léků MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádory prsu farmakoterapie metabolismus patologie MeSH
- organocínové sloučeniny farmakologie MeSH
- proteomika metody MeSH
- retinoidní X receptory agonisté metabolismus MeSH
- signální transdukce účinky léků MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- tandemová hmotnostní spektrometrie MeSH
- tretinoin farmakologie MeSH
- trialkylcínové sloučeniny farmakologie MeSH
- vimentin metabolismus MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
The interplays between the metabolic products of intestinal microbiota and the host signaling through xenobiotic receptors, including pregnane X receptor (PXR), are of growing interest, in the context of intestinal health and disease. A distinct class of microbial catabolites is formed from dietary tryptophan, having the indole scaffold in their core structure, which is a biologically active entity. In the current study, we examined a series of ten tryptophan microbial catabolites for their interactions with PXR signaling. Utilizing a reporter gene assay, we identified indole (IND) and indole-3-acetamide (IAD) as PXR agonists. IND and IAD induced PXR-regulated genes CYP3A4 and MDR1 in human intestinal cancer cells. Using time-resolved fluorescence resonance energy transfer, we show that IND (IC50 292 μM) and IAD (IC50 10 μM) are orthosteric ligands of PXR. Binding of PXR in its DNA response elements was enhanced by IND and IAD, as revealed by chromatin immunoprecipitation assay. We demonstrate that tryptophan microbial intestinal metabolites IND and IAD are ligands and agonists of human PXR. These findings are of particular importance in understanding the roles of microbial catabolites in human physiology and pathophysiology. Furthermore, these results are seminal in expanding potential drug repertoire through microbial metabolic mimicry.
- MeSH
- cytochrom P-450 CYP3A genetika metabolismus MeSH
- indoly metabolismus MeSH
- kultivované buňky MeSH
- kyseliny indoloctové metabolismus MeSH
- lidé MeSH
- ligandy MeSH
- nádorové buněčné linie MeSH
- P-glykoproteiny genetika metabolismus MeSH
- pregnanový X receptor agonisté genetika MeSH
- reportérové geny MeSH
- střevní mikroflóra * MeSH
- střevní sliznice * metabolismus mikrobiologie MeSH
- transfekce MeSH
- tryptofan metabolismus MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
