Precise and efficient endocytosis is critical for sustained neurotransmission during continuous neuronal activity. Endocytosis is a prerequisite for maintaining the auditory function. However, the differences between the patterns of endocytosis in cochlear inner hair cells (IHCs) and outer hair cells (OHCs) remain unclear. Both IHCs and OHCs were obtained from adult C57 mice. Patterns of endocytosis in cells were estimated by analyzing the uptake of FM1-43, a fluorescent. The observations were made using live confocal imaging, fluorescence intensities were calculated statistically. Results revealed the details about following phenomenon, i) sites of entry: the FM1-43 dye was found to enter IHC at the apical area initially, the additional sites of entry were then found at basolateral membrane of the cells, The entry of the dye into OHCs initially appeared to be occurring around whole apical membranes area, which then diffused towards the other membrane surface of the cells, ii) capacity of endocytosis: fluorescence intensity in IHCs showed significantly higher than that of OHCs (P<0.01). We have found different patterns of endocytosis between IHCs and OHCs, this indicated functional distinctions between them. Moreover, FM1-43 dye can be potentially used as an indicator of the functional loss or repair of cochlear hair cells.
- MeSH
- biologický transport fyziologie MeSH
- endocytóza fyziologie MeSH
- fluorescenční barviva analýza metabolismus MeSH
- kvartérní amoniové sloučeniny analýza metabolismus MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- orgánové kultury - kultivační techniky MeSH
- pyridinové sloučeniny analýza metabolismus MeSH
- sluchové evokované potenciály fyziologie MeSH
- vnější vláskové buňky chemie metabolismus MeSH
- vnitřní vláskové buňky chemie metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- fluorescenční barviva MeSH
- FM1 43 MeSH Prohlížeč
- kvartérní amoniové sloučeniny MeSH
- pyridinové sloučeniny MeSH
A series of pentamethinium salts with benzothiazolium and indolium side units comprising one or two positive charges were designed and synthesized to determine the relationships among the molecular structure, charge density, affinity to sulfated polysaccharides, and biological activity. Firstly, it was found that the affinity of the pentamethinium salts to sulfated polysaccharides correlated with their biological activity. Secondly, the side heteroaromates displayed a strong effect on the cytotoxicity and selectivity towards cancer cells. Finally, doubly charged pentamethinium salts possessing benzothiazolium side units exhibited remarkably high efficacy against a taxol-resistant cancer cell line.
- Klíčová slova
- Anticancer activity, Cytotoxicity, Fluorescent cyanine, Pentamethinium salt, Recognition, Sulfated polysaccharides,
- MeSH
- apoptóza účinky léků MeSH
- benzothiazoly chemická syntéza chemie metabolismus farmakologie MeSH
- CHO buňky MeSH
- Cricetulus MeSH
- estery kyseliny sírové metabolismus MeSH
- glykosaminoglykany metabolismus MeSH
- hydrofobní a hydrofilní interakce MeSH
- indoly chemická syntéza chemie metabolismus farmakologie MeSH
- lidé MeSH
- ligandy MeSH
- molekulární struktura MeSH
- nádorové buněčné linie MeSH
- protinádorové látky chemická syntéza chemie metabolismus farmakologie MeSH
- pyridinové sloučeniny chemická syntéza chemie metabolismus farmakologie MeSH
- racionální návrh léčiv MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- audiovizuální média MeSH
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- benzothiazoly MeSH
- estery kyseliny sírové MeSH
- glykosaminoglykany MeSH
- indoly MeSH
- ligandy MeSH
- protinádorové látky MeSH
- pyridinové sloučeniny MeSH
The oximes 4-carbamoyl-1-[({2-[(E)-(hydroxyimino) methyl] pyridinium-1-yl} methoxy) methyl] pyridinium (known as HI-6) and 3-carbamoyl-1-[({2-[(E)-(hydroxyimino) methyl] pyridinium-1-yl} methoxy) methyl] pyridinium (known as HS-6) are isomers differing from each other only by the position of the carbamoyl group on the pyridine ring. However, this slight difference was verified to be responsible for big differences in the percentual of reactivation of acetylcholinesterase (AChE) inhibited by the nerve agents tabun, sarin, cyclosarin, and VX. In order to try to find out the reason for this, a computational study involving molecular docking, molecular dynamics, and binding energies calculations, was performed on the binding modes of HI-6 and HS-6 on human AChE (HssAChE) inhibited by those nerve agents.
- Klíčová slova
- HI-6, HS-6, acetylcholinesterase, chemical defense, molecular modeling,
- MeSH
- acetylcholinesterasa metabolismus MeSH
- chemické bojové látky chemie MeSH
- cholinesterasové inhibitory chemie MeSH
- lidé MeSH
- nervová bojová látka chemie MeSH
- organofosfáty chemie MeSH
- organofosforové sloučeniny chemie MeSH
- organothiofosforové sloučeniny chemie MeSH
- oximy metabolismus MeSH
- pralidoximové sloučeniny metabolismus MeSH
- pyridinové sloučeniny metabolismus MeSH
- sarin chemie MeSH
- simulace molekulární dynamiky MeSH
- simulace molekulového dockingu MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- acetylcholinesterasa MeSH
- asoxime chloride MeSH Prohlížeč
- chemické bojové látky MeSH
- cholinesterasové inhibitory MeSH
- cyclohexyl methylphosphonofluoridate MeSH Prohlížeč
- HS 6 MeSH Prohlížeč
- nervová bojová látka MeSH
- organofosfáty MeSH
- organofosforové sloučeniny MeSH
- organothiofosforové sloučeniny MeSH
- oximy MeSH
- pralidoximové sloučeniny MeSH
- pyridinové sloučeniny MeSH
- sarin MeSH
- tabun MeSH Prohlížeč
- VX MeSH Prohlížeč
BACKGROUND: Based on in vitro and in vivo rat experiments, the newly developed acetylcholinesterase (AChE) reactivator, K203, appears to be much more effective in the treatment of tabun poisonings than currently fielded oximes. METHODS: To determine if this reactivating efficacy would extend to humans, studies were conducted in vitro using human brain homogenate as the source of AChE. The efficacy of K203 was compared with commercially available oximes; pralidoxime, obidoxime and asoxime (HI-6). RESULTS: Reactivation studies showed that K203 was the most effective reactivator with a second order kinetic constant (kr) of 2142 min- 1. M- 1, which was 51 times higher than that obtained for obidoxime (kr = 42 min- 1. M- 1). Both pralidoxime and asoxime (HI-6) failed to significantly reactivate tabun-inhibited human AChE. DISCUSSION: According to these results and previous studies, using K203, it appears that oxime K203 is the most effective reactivator of tabun-inhibited cholinesterase in several species including humans and should be considered as a possible medical countermeasure to tabun exposure.
- Klíčová slova
- Antidotes, Chemical warfare agents, Oxime, Poisoning, Reactivator, Treatment,
- MeSH
- acetylcholinesterasa metabolismus MeSH
- antidota metabolismus MeSH
- cholinesterasové inhibitory metabolismus MeSH
- krysa rodu Rattus MeSH
- lidé MeSH
- mozek enzymologie MeSH
- organofosfáty metabolismus MeSH
- oximy metabolismus MeSH
- pyridinové sloučeniny metabolismus MeSH
- reaktivátory cholinesterasy metabolismus MeSH
- simulace molekulového dockingu MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- 1-(4-carbamoylpyridinium)-4-(4-hydroxyiminomethylpyridinium)but-2-ene MeSH Prohlížeč
- acetylcholinesterasa MeSH
- antidota MeSH
- cholinesterasové inhibitory MeSH
- organofosfáty MeSH
- oximy MeSH
- pyridinové sloučeniny MeSH
- reaktivátory cholinesterasy MeSH
- tabun MeSH Prohlížeč
Organophosphate (OP) poisoning is a major global health issue; while compounds from this group have been used intensively over the last century, an effective antidote is still lacking. Oxime-type acetylcholinesterase (AChE) reactivators are used to reactivate the OP inhibited AChE. Pralidoxime is the only US Food and Drug Administration approved oxime for therapeutic use but its efficacy has been disappointing. Two novel oximes (K378 and K727) were investigated in silico and in vitro and compared with an experimental oxime (kamiloxime; K-27) and pralidoxime. In silico the molecular interactions between AChE and oximes were examined and binding energies were assessed. LogP (predicted log of the octanol/water partition coefficient) was estimated. In vitro the intrinsic ability of the oximes to inhibit AChE (IC50) and their reactivation potency (R50) when used in paraoxon inhibited human RBC-AChE was determined. Molecular docking revealed that K378 and K727 bind to the peripheral site(s) with high binding energies in contrast to the central binding of K-27 and pralidoxime. LogP values indicating that the novel compounds are significantly less hydrophilic than K-27 or pralidoxime. IC50 of K378 and K727 were comparable (0.9 and 1 µM, respectively) but orders of magnitude lower than comparators. R50 values revealed their inability to reactivate paraoxon inhibited AChE. It is concluded that the novel oximes K378 and K727 are unlikely to be clinically useful. The in silico and in vitro studies described allow avoidance of unnecessary in vivo animal work and contribute to the reduction of laboratory animal use.
- Klíčová slova
- K-27, K378, K727, Oximes, organophosphates, paraoxon-ethyl, pralidoxime,
- MeSH
- acetylcholinesterasa krev chemie MeSH
- antidota chemie metabolismus farmakologie MeSH
- cholinesterasové inhibitory chemie metabolismus toxicita MeSH
- GPI-vázané proteiny antagonisté a inhibitory krev chemie MeSH
- konformace proteinů MeSH
- lidé MeSH
- otrava organofosfáty krev farmakoterapie enzymologie MeSH
- oximy chemie metabolismus farmakologie MeSH
- paraoxon analogy a deriváty chemie metabolismus toxicita MeSH
- pralidoximové sloučeniny chemie metabolismus farmakologie MeSH
- pyridinové sloučeniny chemie metabolismus farmakologie MeSH
- reaktivátory cholinesterasy chemie metabolismus farmakologie MeSH
- simulace molekulového dockingu * MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- Názvy látek
- 1-(3-phenylpropyl)-4-hydroxyiminomethylpyridinium MeSH Prohlížeč
- 4-(aminocarbonyl)-1-(3-(4-((E)-(hydroxyimino)methyl)pyridinium-1-yl)propyl)pyridinium dibromide MeSH Prohlížeč
- acetylcholinesterasa MeSH
- ACHE protein, human MeSH Prohlížeč
- antidota MeSH
- cholinesterasové inhibitory MeSH
- ethylparaoxon MeSH Prohlížeč
- GPI-vázané proteiny MeSH
- naphthylene-2,7-diyl-bis(2-hydroxyiminomethylpyridinium) MeSH Prohlížeč
- oximy MeSH
- paraoxon MeSH
- pralidoxime MeSH Prohlížeč
- pralidoximové sloučeniny MeSH
- pyridinové sloučeniny MeSH
- reaktivátory cholinesterasy MeSH
Dinaciclib is a novel cyclin-dependent kinase inhibitor (CDKI) with significant activity against various cancers in vitro and in vivo. ABC efflux transporters play an important role in drug disposition and are responsible for multidrug resistance in cancer cells. Inhibitors and substrates of these transporters may participate in pharmacokinetic drug-drug interactions (DDIs) that alter drug disposition during pharmacotherapy. To assess such risks associated with dinaciclib we evaluated its possible effects on efflux activities of ABCB1, ABCC1 and ABCG2 transporters in vitro. Monolayer transport, XTT cell proliferation, ATPase and intracellular accumulation assays were employed. Here, we show that the transport ratio of dinaciclib was far higher across monolayers of MDCKII-ABCB1 and MDCKII-ABCG2 cells than across MDCKII parental cell layers, demonstrating that dinaciclib is a substrate of ABCB1 and ABCG2. In addition, overexpression of ABCB1, ABCG2 and ABCC1 conferred resistance to dinaciclib in MDCKII cells. In ATPase assays, dinaciclib decreased stimulated ATPase activity of ABCB1, ABCG2 and ABCC1, confirming it has interactive potential toward all three transporters. Moreover, dinaciclib significantly inhibited ABCC1-mediated efflux of daunorubicin (EC50=18 μM). The inhibition of ABCC1 further led to a synergistic effect of dinaciclib in both MDCKII-ABCC1 and human cancer T47D cells, when applied in combination with anticancer drugs. Taken together, our results suggest that ABC transporters can substantially affect dinaciclib transport across cellular membranes, leading to DDIs. The DDIs of dinaciclib with ABCC1 substrate chemotherapeutics might be exploited in novel cancer therapies.
- Klíčová slova
- ABCB1, ABCC1, ABCG2, Cytotoxicity, Dinaciclib, Dinaciclib (PubChem CID: 46926350), Multidrug resistance,
- MeSH
- ABC transportér z rodiny G, člen 2 MeSH
- ABC transportéry metabolismus MeSH
- adenosintrifosfatasy metabolismus MeSH
- bicyklické sloučeniny heterocyklické metabolismus farmakologie MeSH
- biologický transport MeSH
- buňky MDCK MeSH
- cyklické N-oxidy MeSH
- cyklin-dependentní kinasy antagonisté a inhibitory MeSH
- indoliziny MeSH
- inhibitory proteinkinas metabolismus farmakologie MeSH
- lidé MeSH
- nádorové proteiny metabolismus MeSH
- P-glykoproteiny metabolismus MeSH
- proteiny spojené s mnohočetnou rezistencí k lékům metabolismus MeSH
- psi MeSH
- pyridinové sloučeniny metabolismus farmakologie MeSH
- techniky in vitro MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- ABC transportér z rodiny G, člen 2 MeSH
- ABC transportéry MeSH
- ABCB1 protein, human MeSH Prohlížeč
- ABCG2 protein, human MeSH Prohlížeč
- adenosintrifosfatasy MeSH
- bicyklické sloučeniny heterocyklické MeSH
- cyklické N-oxidy MeSH
- cyklin-dependentní kinasy MeSH
- dinaciclib MeSH Prohlížeč
- indoliziny MeSH
- inhibitory proteinkinas MeSH
- multidrug resistance-associated protein 1 MeSH Prohlížeč
- nádorové proteiny MeSH
- P-glykoproteiny MeSH
- proteiny spojené s mnohočetnou rezistencí k lékům MeSH
- pyridinové sloučeniny MeSH
BACKGROUND: Processes of anterograde and retrograde membrane trafficking play an important role in cellular homeostasis and dynamic rearrangements of the plasma membrane (PM) in all eukaryotes. These processes depend on the activity of adenosine ribosylation factors (ARFs), a family of GTP-binding proteins and their guanine exchange factors (GEFs). However, knowledge on the function and specificity of individual ARF-GEFs for individual steps of membrane trafficking pathways is still limited in plants. RESULTS: In this work, treatments with various trafficking inhibitors showed that the endocytosis of FM 4-64 is largely dynamin-dependent and relies on proteins containing endocytic tyrosine-based internalization motif and intact cytoskeleton. Interestingly, brefeldin A (BFA), reported previously as an inhibitor of anterograde membrane trafficking in plants, appeared to be the most potent inhibitor of endocytosis in tobacco. In concert with this finding, we demonstrate that the point mutation in the Sec7 domain of the GNOM-LIKE protein1a (NtGNL1a) confers intracellular trafficking pathway-specific BFA resistance. The internalization of FM 4-64 and trafficking of PIN-FORMED1 (PIN1) auxin efflux carrier in BY-2 tobacco cells were studied to reveal the function of the ARF-GEF NtGNL1a in these. CONCLUSIONS: Altogether, our observations uncovered the role of NtGNL1a in endocytosis, including endocytosis of PM proteins (as PIN1 auxin efflux carrier). Moreover these data emphasize the need of careful evaluation of mode of action of non-native inhibitors in various species. In addition, they demonstrate the potential of tobacco BY-2 cells for selective mapping of ARF-GEF-regulated endomembrane trafficking pathways.
- MeSH
- endocytóza MeSH
- kvartérní amoniové sloučeniny metabolismus MeSH
- pyridinové sloučeniny metabolismus MeSH
- rostlinné buňky fyziologie MeSH
- rostlinné proteiny genetika metabolismus MeSH
- tabák genetika fyziologie MeSH
- transport proteinů MeSH
- výměnné faktory guaninnukleotidů genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- FM 4-64 MeSH Prohlížeč
- kvartérní amoniové sloučeniny MeSH
- pyridinové sloučeniny MeSH
- rostlinné proteiny MeSH
- výměnné faktory guaninnukleotidů MeSH
The blood-brain barrier plays a vital role in the protection of the central nervous system. It is composed of endothelial cells with tight-junctions to limit the penetration of many endogenous and exogenous compounds, particularly hydrophilic xenobiotics. Nerve agents and pesticides are groups of compounds with high penetration potential into the central nervous system. However, oxime type antidotes are known to penetrate blood-brain barrier only in low concentration. The aim of presented study is to describe the pharmacokinetic profile of oxime K027 a novel antidote candidate. The main focus is on penetration of tested substance into the selected brain regions following time-dependent manner. The maximum concentration of the oxime K027 was attaining 15 and 30 min after i.m. application in plasma and brain tissue, respectively. The perfused brain tissue concentration was relatively high (10(-7) M order of magnitude) and depending on the brain region it was constant 15-60 min after application. The highest concentration was found in the frontal cortex 15 min after application while the lowest measured concentration was determined in the basal ganglia. This study showed that oxime K027 is able to achieve high concentration level in perfused brain tissue relatively quickly, but also demonstrated rapid clearance from the central nervous system. These results are probably due to low overall uptake of oxime K027 into the brain.
- MeSH
- časové faktory MeSH
- centrální nervový systém účinky léků metabolismus MeSH
- hematoencefalická bariéra účinky léků metabolismus MeSH
- krysa rodu Rattus MeSH
- mozek účinky léků metabolismus MeSH
- oximy metabolismus farmakokinetika MeSH
- potkani Wistar MeSH
- pyridinové sloučeniny metabolismus farmakokinetika MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- 1-(4-hydroxyiminomethylpyridinium)-3-(carbamoylpyridinium) propane dibromide MeSH Prohlížeč
- oximy MeSH
- pyridinové sloučeniny MeSH
The antidotal treatment of organophosphorus poisoning is still a problematic issue since no versatile antidote has been developed yet. In our study, we focused on an interesting property, which does not relate to the reactivation of inhibited acetylcholinesterase (AChE) of some oximes, but refers to their anti-muscarinic effects which may contribute considerably to their treatment efficacy. One standard reactivator (HI-6) and two new compounds (K027 and K203) have been investigated for their antimuscarinic properties. Anti-muscarinic effects were studies by means of an in vitro stimulated atrium preparation (functional test), the [(3)H]-QNB binding assay and G-protein coupled receptor assay (GPCR, beta-Arrestin Assay). Based on the functional data HI-6 demonstrates the highest anti-muscarinic effect. However, only when comparing [(3)H]-QNB binding results and GPCR data, K203 shows a very promising compound with regard to anti-muscarinic potency. The therapeutic impact of these findings has been discussed.
- MeSH
- acetylcholinesterasa metabolismus MeSH
- agonisté muskarinových receptorů farmakologie MeSH
- antagonisté muskarinových receptorů farmakologie MeSH
- chinuklidinylbenzilát metabolismus MeSH
- elektrická stimulace MeSH
- krysa rodu Rattus MeSH
- oximy metabolismus farmakologie MeSH
- oxotremorin analogy a deriváty farmakologie MeSH
- potkani Wistar MeSH
- pyridinové sloučeniny metabolismus farmakologie MeSH
- reaktivátory cholinesterasy metabolismus farmakologie MeSH
- receptory muskarinové účinky léků MeSH
- receptory spřažené s G-proteiny metabolismus MeSH
- srdeční frekvence účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- acetylcholinesterasa MeSH
- agonisté muskarinových receptorů MeSH
- antagonisté muskarinových receptorů MeSH
- asoxime chloride MeSH Prohlížeč
- chinuklidinylbenzilát MeSH
- oximy MeSH
- oxotremorin MeSH
- oxotremorine M MeSH Prohlížeč
- pyridinové sloučeniny MeSH
- reaktivátory cholinesterasy MeSH
- receptory muskarinové MeSH
- receptory spřažené s G-proteiny MeSH
Assay of acetylcholinesterase (AChE) activity plays an important role in diagnostic, detection of pesticides and nerve agents, in vitro characterization of toxins and drugs including potential treatments for Alzheimer's disease. These experiments were done in order to determine whether indoxylacetate could be an adequate chromogenic reactant for AChE assay evaluation. Moreover, the results were compared to the standard Ellman's method. We calculated Michaelis constant Km (2.06 × 10(-4) mol/L for acetylthiocholine and 3.21 × 10(-3) mol/L for indoxylacetate) maximum reaction velocity V(max) (4.97 × 10(-7) kat for acetylcholine and 7.71 × 10(-8) kat for indoxylacetate) for electric eel AChE. In a second part, inhibition values were plotted for paraoxon, and reactivation efficacy was measured for some standard oxime reactivators: obidoxime, pralidoxime (2-PAM) and HI-6. Though indoxylacetate is split with lower turnover rate, this compound appears as a very attractive reactant since it does not show any chemical reactivity with oxime antidots and thiol used for the Ellman's method. Thus it can be advantageously used for accurate measurement of AChE activity. Suitability of assay for butyrylcholinesterase activity assessment is also discussed.
- Klíčová slova
- 5,5′-dithio-bis-2-nitrobenzoic acid, Alzheimer’s disease, acetylcholinesterase, enzyme activity, indoxylacetate, nerve agents, oxime reactivator,
- MeSH
- acetylcholinesterasa metabolismus MeSH
- cholinesterasové inhibitory chemie metabolismus MeSH
- enzymatické testy * MeSH
- indoly chemie metabolismus MeSH
- kinetika MeSH
- kyselina dithionitrobenzoová chemie metabolismus MeSH
- obidoxim chlorid chemie metabolismus MeSH
- oximy chemie metabolismus MeSH
- paraoxon chemie metabolismus MeSH
- pralidoximové sloučeniny chemie metabolismus MeSH
- pyridinové sloučeniny chemie metabolismus MeSH
- reaktivátory cholinesterasy chemie metabolismus MeSH
- substrátová specifita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- acetylcholinesterasa MeSH
- asoxime chloride MeSH Prohlížeč
- cholinesterasové inhibitory MeSH
- indoly MeSH
- indoxyl acetate MeSH Prohlížeč
- kyselina dithionitrobenzoová MeSH
- obidoxim chlorid MeSH
- oximy MeSH
- paraoxon MeSH
- pralidoxime MeSH Prohlížeč
- pralidoximové sloučeniny MeSH
- pyridinové sloučeniny MeSH
- reaktivátory cholinesterasy MeSH